Rne Fundamentals B11 tn4v

= 0 πR²

F rec, thr

0

R = f (hBS, hMS, f, Kmor, EIRP, Frec,thr)

1 · 1 · 188

R

r

r = distance between BTS and MS Frec = received power σ = Standard deviation

All Rights Reserved © Alcatel-Lucent 2010

Basics · Basics RNE · RNE (Radio Network Engineering) B11 Fundamentals

All Rights Reserved © Alcatel-Lucent 2010 TMO54014 Issue 01

2.7 Cell Range Calculation

2.7.2 Coverage Probability

Pcov 0,95

(r)

Pcov = P ( Frec > Frec, thr )

1

0,5

0

r

R 1 · 1 · 189





2.7.3 Coverage Ranges and Hata Correction Factors

Area Coverage Probability 100%

95%

Reference Pathloss [dB]

90% 155

Pcov

150 145

85%

140 135 130

Clutter type Skyscrapers Dense urban Medium urban Lower urban Residential Industrial zone Forest Agricultural Low tree density Water Open area

Cor [dB] σ [dB] 0 6 2 6 4 7 6 7 8 6 10 10 8 8 20 6 15 8 27 5 27 6

125

80%

120 115 110

75%

Calculation conditions: 70% 0,0

1,5

3,0

4,5

6,0

7,5

9,0

Correction = 3; Sigma = 7 hBS = 30 m; hMS = 1.7m; f = 900 Mhz

10,5

d [km]

1 · 1 · 190



The lognormal distribution, described by a mean fieldstrength Fmed and a standard deviation s, is shown in in the left diagram. A coverage probability Pcov can be calculated, which defines the chance that a certain fieldstrength threshold Fthr is reached or exceeded by the calculated (or predicted) mean fieldstrength level Fmed. This probability is represented by the area enclosed by the graph of the probability density function and the vertical line at F=Fthr in the left diagram. The variation of the probability in dependence on Fmed is shown in the right diagram. The required difference between Fmed and Fthr in order to achieve a required probability is called the fading margin. Without any margin, the probability is 50%, which is not a sufficient value in order to provide a good call success rate. A typical design goal should be a coverage probability of 90...95%. The following normalized table can be applied to find fading margins for different values of s. The fading margin is calculated by multiplying the value of k (in the table) with the standard deviation (Fading Margin = k s).

k

-∞

-0.5

0

1

1.3

1.65

2

2.33

+∞

Coverage Probability

0%

30%

50%

84%

90%

95%

97.7%

99%

100%



TX and RX

TX

2.7.4 Conventional BTS Configuration

1 BTS Omnidirectional antenna for both TX and RX Coverage Range R0 Coverage Area A0

ALCATEL EvoliumTM

R0

TX → 45.4 dBm RX → -109dBm

A0

1 · 1 · 191





2.7.5 Coverage Improvement by Antenna Diversity

one for both RX and TX one for RXDIV RXDIV

TX and TX RX

1 BTS Omnidirectional antennas Antenna diversity gain (2...6 dB) Example: 3 dB

Coverage range RDiv = 1.23 · R0 Coverage area ADiv = 1.5 · A0

R0

ALCATEL EvoliumTM

TX → 45.4 dBm RX → -109dBm

A0 ADiv 1 · 1 · 192




RDiv


2.7.6 Radiation Patterns and Range

sector omni

3 antennas at sector site, Gain: 18 dBi, HPBW: 65°

1 · 1 · 193

Resulting antenna footprint ("cloverleaf") compared to an 11 dBi omni antenna





2.7.7 Improvement by Antenna Diversity and Sectorization

TX

RXDIV

3 BTS Directional antennas (18 dBi) Antenna diversity (3 dB) Max. coverage range Rsec,div = 1.95 · R0 Coverage area Asec,div = 3 · A0

R0

ALCATEL EvoliumTM ALCATEL EvoliumTM

Rsec,div

ALCATEL EvoliumTM

Asec,div

1 · 1 · 194





2.7.8 Improvement by Antenna Preamplifier

RXDIV

3 BTS Directional antennas (18 dBi) Antenna diversity (3 dB) Antenna preamplifier (3dB) Max. coverage range Rsec,div,pre = 2.22 · R0 Coverage area Asec,div,pre = 3.9 · A0

TX

General: Asec = g · A0 g: Area gain factor

R0

ALCATEL EvoliumTM

Rsec,div,pre

ALCATEL EvoliumTM ALCATEL EvoliumTM

1 · 1 · 195

Asec,div,pre




2 Coverage Planning

2.8 Antenna Engineering

1 · 1 · 196





2.8.1 Omni Antennas

Application Large area coverage Umbrella cell for micro cell layer

Advantages Continuous coverage around the site Simple antenna mounting Ideal for homogeneous terrain

Drawbacks No mechanical tilt possible Clearance of antenna required Densification of network difficult

1 · 1 · 197





2.8.2 Sector Antenna

Antenna with horizontal HPBW of e.g. 90° or 65° Advantages Coverage can be focussed on special areas Low coverage of areas of no interest (e.g. forest) Allows high traffic load Additional mechanical downtilt possible Wall mounting possible

Drawbacks More frequencies needed per site compared to omni sites More hardware needed Lower coverage area per sector

1 · 1 · 198





2.8.3 Typical Applications

Wide horizontal beam width (e.g. 90°) For areas with few reflecting and scattering objects (rural area) Area coverage for 3-sector sites Sufficient cell overlap to allow successful handovers

Small horizontal beam width (e.g. 65°) For areas with high scattering (city areas) Coverage between sectors by scattering and by adjacent sites (mostly site densification in urban areas)

1 · 1 · 199





2.8.4 Antenna Tilt

Downtilting of the Antenna main beam related to the horizontal line Goals: Reduction of overshoot Removal of insular coverage Lowering the interference Coverage improvement of the near area (indoor coverage) Adjustment of cell borders (handover zones)

Mechanical / Electrical or Combined downtilt

1 · 1 · 200





2.8.5 Mechanical Downtilt Advantages Later adjustment of vertical tilt possible Antenna diagram is not changed, i.e. nulls and side lobes remain in their position relative to the main beam Cost effective (single antenna type may be used) Fast adjustments possible

Drawbacks Side lobes are less tilted Accurate adjustment is difficult Problems for sites with difficult access

1 · 1 · 201





2.8.6 Electrical Downtilt

τ=0

Advantages Same tilt for both main and side lobes downtilt angle Antenna mounting is more simple adjustment errors

Drawbacks

τ=t → no

τ = delay time Introduction of additional antenna types necessary New antenna installation at the site if downtilting is introduced Long antenna optimization phase Adjustment of electrical tilt mostly not possible

1 · 1 · 202




τ=2t τ=3t


2.8.7 Combined Downtilt Combination of both mechanical and electrical downtilt High electrical downtilt: Distinct range reduction in sidelobe direction (interference reduction) Less mechanical uptilt in main beam direction

Choose sector antennas with high electrical downtilt (6°...8°) and apply mechanical uptilt installation for optimum coverage range in main beam direction

1 · 1 · 203





2.8.8 Assessment of Required Tilts

Required tilt is estimated using Geometrical Optics Consideration of Vertical HPBW of the antenna Antenna height above ground Height difference antenna/location to be covered Morpho-structure in the vicinity of the antenna Topography between transmitter and receiver location

Tilt must be applied for both TX and RX antennas!

1 · 1 · 204





2.8.9 Inter Site Distance in Urban Area Using sectorized sites with antennas of 65° horizontal half power beam width The sidelobe is approximately reduced by 10dB. This is a reduction of cell range to 50%. X A

B

X

The inter site distance calculation factor depends on Type of antenna Type of morpho class Multi path propagation Scattering Sigma (fading variations)

R2

1 · 1 · 205

0.5* R2





2.8.10 Downtilt in Urban Area

Site A

Tilt 2

Tilt 2

M ai n

e ob el d i S

be am

Cell range R2

0.5* R2

Inter Site Distance A-B = 1.5* R2

1 · 1 · 206




Site B


2.8.11 Downtilt in Urban Area The upper limit of the vertical half power beam width is directed towards the ground at maximum cell range Upper –3dB point of the vertical antenna pattern

To be used in areas with Multi path propagation condition Good scattering of the beam

Aim Reduction of interference

Optimization Coverage Optimization in isolated cases using less downtilt Interference Reduction in isolated cases using more downtilt

1 · 1 · 207





2.8.12 Downtilt in Suburban and Rural Area Downtilt planning for Suburban Rural Highway Coverage

The main beam is directed towards the ground at maximum cell range

Tilt 1

Tilt 1

Site C

Ma in b

Site D eam in b Ma

eam

Cell range R1

Cell range R1

Inter Site Distance C-D = 2* R1

1 · 1 · 208





2.8.13 Antenna configurations Rx/Tx

Application of Duplexer Consists of a TX/RX Filter and a combiner one antenna can be saved

Tower Mounted Amplifier (TMA) Increase Uplink Sensitivity TMA needs to have TX by => in case of duplexer usage

Diversity

Duplex Filter

Space diversity Polarization diversity

Tx Rx To BTS 1 · 1 · 209





2.8.14 Antenna Configurations for Omni and Sector Sites Antenna Configurations for Omni and Sector Sites Sector antenna

Pole mounting for roof-top mounting

Bracons

Rxdiv

Tx

Rxdiv

Rx

Rx

Tx

Pole

Sector Antenna

Pole Tower mounting for omni antennas

1 · 1 · 210

Tower mounting for directional antennas




Pole mounting for wall or parapet mounting


2.8.15 Three Sector Antenna Configuration with AD

1 · 1 · 211





2.8.16 Antenna Engineering Rules

Distortion of antenna pattern: No obstacles within Antenna near field range HPBW Rule plus security margin of 20° First fresnel ellipsoid range (additional losses!)

TX-RX Decoupling to avoid blocking and intermodulation Required minimum separation of TX - RX antennas dependent on antenna configuration (e.g. duplexer or not)

Diversity gain Required antenna separation for space diversity

1 · 1 · 212





2.8.17 Distortion of antenna pattern

Antenna Near Field Range: Rmin = 2D²/λ D = Aperture of antenna (e.g. 3m) => Rmin = 60 / 120m for GSM / DCS

HPBW Rule with securtiy margin of 20° and tilt α

ϕ

H

Roof Top = Obstacle D 1 · 1 · 213

ϕ = HPBW/2 + 20° + α D[m] 1 5 10 H[m] 0.5 2.5 5 HPBW = 8°, α = 2°





2.8.18 Tx-Rx Decoupling (1) Out of Band Blocking Requirement (GSM Rec. 11.21) GSM 900 GSM 1800

= +8 dBm = 0 dBm

Required Decoupling TX-TX TX-RX GSM TX-RX DCS

(n = number of transmitters)

= 20 dB = 30 + 10 log (n) dB = 40 + 10 log (n) dB

Receiver Pout Characteristic

P [dBm] fuse

-13

-101

TX

fint

RX

n*200kHz

fuse

1 · 1 · 214

fint

P1dB

f[MHz]




Pblock

Pin


2.8.19 TX-RX Decoupling (2) Horizontal separation (Approximation) Isolation for Horizontal Separation - omni 11dBi 45

dH

I =22+20log(d/λ)-(G +G ) [dB] H

H

T

Isolation [dB]

40

GSM1800

35 30

GSM900

25

R

20

Separation [m ]

1 · 1 · 215




14 14 ,4 14 ,8 15 ,2

12 12 ,4 12 ,8 13 ,2 13 ,6

5, 7 6, 7 7, 7 8, 7 9, 7 10 ,4 10 ,8 11 ,2 11 ,6

1, 7 2, 7 3, 7 4, 7

15


2.8.20 TX-RX Decoupling (3)

Vertical separation (Approximation) Isolation for Vertical Separation 70 60

dv

dm

GSM1800

40 30

GSM900

20

I =28+40log(d /λ) [dB] V

50 Isolation [dB]

Mast

V

10 0 0,2

0,3

0,4

0,5

0,6 Separation [m]

1 · 1 · 216




0,7

0,8

0,9

1


2.8.21 Space Diversity Required separation for max. diversity gain = F(λ)

RXA dV

dH RXA

RXB

For a sufficient low correlation coefficient ρ < 0.7: dH = 20λ => GSM 900: 6m / GSM1800: 3m dV = 15λ => GSM 900: 4.5m / GSM1800: 2.25m

1 · 1 · 217




RXB


2.8.22 Power Divider Power dividers connect several antennas to one feeder cable

Quasi-Omni Configuration

For combination of individual antenna patterns for a requested configuration Quasi-omni configuration Bidirectional configuration (road coverage)

4-to-1 Power splitter (6 dB loss)

To BTS: Duplexer output (TX plus RX diversity) 1 · 1 · 218




To BTS: Receiver input


2.8.23 Power Divider

Power divider Also called "power splitter" or "junction box" ive device (works in both (transmit and receive) direction) Pin

Pin

Pin

Pin

Pin

Pin

Pin

Pin

Pin

2

2

3

3

3

4

4

4

4

3 dB

Pin

1 · 1 · 219

4.5 dB

Pin




6 dB

Pin


2.8.24 Configurations (1) Radial Arrangement of 6 Antennas with horizontal beamwidth = 105 ° gain = 16.5 dBi, mast radius = 0.425 m, mounting radius = 0.575 m

1 · 1 · 220





2.8.25 Configurations (2) Example 2: Quasi Omni Arrangement of 3 antennas with horizontal beamwidth = 105 °, gain =13.5 dBi, mounting radius = 4 m

1 · 1 · 221





2.8.26 Configurations (3) Example 3: Skrew Arrangement

of 4 Antennas with horizontal beamwidth = 65 °, gain = 12.5 dBi, mast radius = 1 m, mounting radius = 1.615 m

1 · 1 · 222




2.8 Antenna Engineering 2.8.27 Feeders

Technical summary Inner conductor: Copper wire Dielectric:

Low density foam PE Inner conductor Outer conductor

Outer conductor: Corrugated copper tube Jacket:

Polyethylene (PE) black Dielectric

1 · 1 · 223




Jacket


2.8.28 Feeder Installation Set and Connectors

1 Cable Clamps 2 Antenna Cable 3 Double Bearing 4 Counterpart 5 Anchor tape

1 · 1 · 224

7/16 Connector: Coaxial Connector Robust Good RF-Performance





2.8.29 Feeder Parameters

Type

Minimum bending radius

Jacket (outer diameter)

Weight (m)

Recommended clamp spacing

Single bending

Repeated bending

LCF 1/2’’

70 mm

210 mm

16 mm

0.35 kg

0.6 m

LCF 7/8’’

120 mm

360 mm

28 mm

0.62 kg

0.8 m

LCF 1 5/8’’

300 mm

900 mm

49.7 mm

1.5 kg

1.2 m

GSM 900 Type LCF 1/2“ LCF 7/8“ LCF 1_5/8“

Attenuation /100 m [dB] 6.6 4.0 2.6

GSM 1800

Recommended max length [m] 45 75 115

Attenuation /100 m [dB] 10.3 6.0 4.0


GSM 1900 Attenuation /100 m [dB] 10.6 6.3 4.2

These values are based on feeder types with an impedance of 50 ohms

1 · 1 · 225






2.8.30 Feeder attenuation (1)

Main contribution is given by feeder loss Feeder Cable 4dB/100m => length 50m Loss =2.0dB Jumper Cable 0.066dB/1m => 5m Loss =0.33dB Insertion Loss of connector and power splitter < 0.1dB Total Loss 2.0dB+2x0.33dB+5x0.1dB+0.1dB =3.26dB

Cable type is trade off between Handling flexibility Cost Attenuation

1 · 1 · 226




2.8 Antenna Engineering 2.8.31 Radiating Cables

Provide coverage in Tunnels, buildings, along side tracks or lines Principle: Radiate a weak but constant electromagnetic wave Suitable for coverage over longer distances (Repeater) Fieldstrength distribution more constant as with antennas

Repeater

F F

F Thr

1 · 1 · 227

F

Thr




Terminating Load


2.8.32 Components of a radiating cable system

Components are shown with black lines N-connections Radiating cable

Tx

Termination load

BTS Rx

Jumper cabel

Mounting clips with 50 mm wall standoff

1-leg radiating cable system

1 · 1 · 228




Earthing kit

2.8.33 Comparison of field strength: Radiating cable and standard antenna

-40 -50

[dBm]

-60

Cable attenuation between the antennas

-70 -80

Radiating cable field strength

-90 -100

Antenna field strength

-110 Distance

1 · 1 · 229





2.8.34 Example of a radiating cable in a tunnel

Example of a radiating cable in a tunnel

1 · 1 · 230





2.8.35 Microwave antennas, feeders and accessories

Microwave point to point systems use highly directional antennas Gain 4π A e G = 10 lg

with

λ2

G = gain over isotropic, in dBi A = area of antenna aperture e = antenna efficiency

Used antenna types parabolic antenna high performance antenna horn lens antenna horn antenna

1 · 1 · 231





2.8.36 Parabolic antenna Parabolic dish, illuminated by a feed horn at its focus Available sizes: 1’ (0.3 m) up to 16’ (4.8 m) Sizes over 4’ seldom used due to installation restrictions Single plane polarized feed vertical (V) or horizontal (H) Also: dual polarized feeder (DP), with separate V and H connections (lower gain) Front-to-back ratios of 45 dB not high enough for back-to-back configuration on the same frequency Antenna patterns are absolutely necessary for interference calculations

1 · 1 · 232



Parabolic dish, illuminated by a feed horn at its focus. Available in a wide variety of sizes [1’ (0.3 m), 2’ (0.6 m), 4’ (1.2 m), 6’ (1.8 m), 8’ (2.4 m), 10’ (3.0 m) and sometimes up to 16’ (4.8 m) in most frequency bands. Sizes over 4’ are seldom used due to the installation restrictions on private buildings Mostly with single plane polarised feed, which can be either vertical (V) or horizontal (H) Dual polarized feeds (DP), with separate V and H connections possible DP`s usually have lower gain than single polarized antennas Front-to-back ratios of about 45 dB are not high enough to use these antennas back-to-back on the same frequency (interference calculations) Antenna patterns are absolutely necessary for interference calculations



2.8.37 High performance antenna Similar to common parabolic antenna, except for attached cylindrical shield Improvement of front-to-back ratio and wide angle radiation discrimination Available in same sizes as parabolic, single or dual polarized Substantially bigger, heavier, and more expensive than parabolic antennas Allow back-to-back transmission at the same frequency in both directions (refer to interference calculation)

1 · 1 · 233



Similar to the common parabolic antenna, except for an attached cylindrical shield Improvement of the front-to-back ratio, and wide angle radiation discrimination Available in the same sizes as parabolic ones, either single or double polarised Substantially bigger, heavier, and more expensive than the ordinary parabolics Allow back-to-back transmision at the same frequency in both directions (refer to interference calculation)



2.8.38 Horn antennas Horn lens antenna For very high frequencies > 25 GHz Replacement for small parabolic antennas (1’) Same electrical data, but easier to install due to size and weight Horn reflector antenna Large parabola, energy from the feed horn is reflected at right angle (90°) Gain like 10’ parabolic antenna (60 dBi), but higher front-to-back ratios > 70 dB

Big and heavy, requires a complex installation procedure Only used on high capacity microwave backbones (e.g. MSC-MSC interconnections)

1 · 1 · 234



Horn lens antenna Only available for very high frequencies (above 25 Ghz) Replacement for small parabolic antennas (1’) Electrical data nearly the same, but easier to install due to their size and weight Horn reflector antenna Consists of a very large parabola, mounted at such an angle that the energy from the feed horn is reflected at right angle (90°) Gain in the region of a 10’ parabolic antenna (60 dBi), but it has much higher front-to-back ratios ( 70 dB or more) Very big, heavy and requires a complex installation procedure Only used on high capacity microwave backbones (example: MSC-MSC interconnections).



2.8.39 Specific Microwave Antenna Parameters (1) Cross polarization discrimination (XPD) highest level of cross polarisation radiation relative to the main beam; should be > 30 dB for parabolic antennas

Inter-port isolation isolation between the two ports of dual polarised antennas; typical value: better than 35 dB

Return loss (VSWR) Quality value for the adaption of antenna impedance to the impedance of the connection cable Return loss is the ratio of the reflected power to the power fed at the antenna input (typical> 20 dB)

1 · 1 · 235





2.8.40 Specific Microwave Antenna Parameters (2)

Radiation pattern envelope (RPE) Tolerance specification for antenna pattern (specification of antenna pattern itself not suitable due to manufacturing problems) Usually available from manufacturer in vertical and horizontal polarisation (worst values of several measurements) Weight Wind load

1 · 1 · 236





2.8.41 Data sheet 15 GHz

Bandwidth Model number Nominal diameter

(GHz)

Half-power beamwidth Gain low band Gain mid band Gain high band Front-to-back ratio Cross polar discrimination Return loss

(deg) (dBi) (dBi) (dBi) (dB) (dB) (dB)

2.3 36.2 36.5 36.7 42 28 26

1.2 42.3 42.5 42.8 48 30 26

0.8 45.8 46.0 46.3 52 30 28

Weight Windload Elevation adjustment

(kg)

19

43

73

(deg)

+/- 5

+/- 5

+/- 5

(m) (ft)

14.4 - 15.35 14.4 - 15.35 14.4 - 15.35 PA 2 - 144 PA 4 - 144 PA 6 - 144 0.6 1.2 1.8 2 4 6

Parabolic antenna 15 GHz

1 · 1 · 237

Bandwidth Model number Nominal diameter

(GHz)

Half-power beamwidth Gain low band Gain mid band Gain high band Front-to-back ratio Cross polar discrimination Return loss

(deg) (dBi) (dBi) (dBi) (dB) (dB) (dB)

2.3 36.2 36.5 36.7 65 28 26

1.2 42.3 42.5 42.8 68 30 26

0.8 45.8 46.0 46.3 68 30 26

Weight Windload Elevation adjustment

(kg)

28

55

130

(deg)

+/- 12

+/- 12

+/- 12

(m) (ft)

14.4 - 15.35 14.4 - 15.35 14.4 - 15.35 DA2 - 144 DA4 - 144 DA6 - 144 0.6 1.2 1.8 2 4 6

High performance antenna 15 GHz





2.8.42 Radiation pattern envelope

1 · 1 · 238




Depending on the frequency coaxial cables and waveguides are used for the transmission of RF energy 2.8radio Antenna Engineering between systems and antennas. The most important characteristic of feeders is their loss, but also 2.8.43 Feeders their impedance (return loss). (1)

Coaxial cables or waveguides (according to frequency) Most important characteristic: loss and return loss Coaxial cables Used between 10 MHz and 3 GHz Dielectric material: foam or air Parameters of common coaxial cables:

type

dielectric

diameter (mm)

loss (dB/100m)

power rating (kW)

bending radius (mm)

LCF 1/2’ CU2Y

foam

16.0

0.47

200

LCF 7/8’ CU2Y

foam

28.0

0.95

360

LCF 1 5/8’ CU2Y

foam

49.7

10,9 / 2 GHz 13.8 / 3 GHz 6.5 / 2 GHz 8.5 / 3 GHz 4.4 / 2 GHz 5.6 / 3 GHz

1.7

380

1 · 1 · 239





2.8.44 Feeders (2)

Waveguides Used for frequency bands above 2.5 GHz Three basic types available: circular, elliptical and rectangular

Rigid circular waveguide Very low loss s two orthogonal polarisations Capable to carry more than one frequency band Usually, short components of this type are used Disadvantages: cost, handling and moding problems

1 · 1 · 240





2.8.45 Feeders (3) Elliptical semiflexible waveguides Acceptable loss, good VSWR performance Low cost and easy to install Various types optimised for many frequency bands up to 23 GHz Used for longer distances (easy and flexible installation) Can be installed as a "single run" (no intermediate flanges)

1 · 1 · 241

type

loss /100 m

Frequency

EW 34 EW 52 EW 77 EW 90 EW 220

2.0 4.0 5.8 10.0 28.0

4 GHz 6GHz 8GHz 11 GHz 23 GHz





2.8.46 Feeders (4) Solid and flexible rectangular waveguides Solid rectangular waveguides Combination of low VSWR and low loss High cost and difficult to install Used for realising couplers, combiners, filters

1 · 1 · 242

type

loss /100 m

Frequency

WR 229 WR159 WR112 WR 90 WR 75

2.8 4.5 8.5 11.7 15.0

4 GHz 6GHz 8GHz 11 GHz 13 GHz





2.8.47 Feeders (5)

Flexible rectangular waveguides Worse VSWR and losses than for solid waveguides Often used in short lengths (<1 m), where position between connection points depends on actual installation place Common applications: connection of microwave system to antenna (close together on rooftops or towers) for frequencies >13 Ghz

1 · 1 · 243

type

loss / m

Frequency

PDR140 PDR180 PDR220

0.5 1 2

15GHz 18 GHz 23 GHz





2.8.48 Antenna feeder systems (1) Direct radiating system Most commonly used for frequencies up to 13 Ghz Depending on accepted feeder loss/length, higher frequencies may be possible Excessive attenuation and costs in long runs of wave guide Occurence of echo distortion due to mismatch in long runs of waveguide possible

1 · 1 · 244





2.8.49 Antenna feeder systems (2) Periscope antenna system Used for considerable antenna heights waveguide installation problems

Negligible wave guide cost and easy installation System gain is a function of antenna and reflector size, distance and frequency Used above 4 GHz , because reflector size is prohibitive for lower frequencies

1 · 1 · 245





2.8.50 Antenna feeder systems (3) Combined antenna with transceiver Antenna and transceiver are combined as a single unit to cut out wave guide loss (higher frequencies) Units are mounted on top of a mast and connected to multiplex equipment via cable

1 · 1 · 246




2 Coverage Planning

2.9 Alcatel BSS

1 · 1 · 247




2.9 Alcatel BSS

2.9.1 Architecture of BTS - Evolium Evolution A9100 Air interface

3 levels Antenna network stage

Antenna network stage

ANC or ANB (note)

ANC

Antenna coupling level Combiner stage (ANY)

TRX level

TRX

BCF level

TRX

TRX

TRX

TRX

TRX

TRX

TRX

Combiner stage (ANY)

TRX

TRX

TRX

TRX

Station unit module Abis interface

Abbreviations BCF

Base station Control Function

TRX

Transceiver

Note 1 : ANB module is limited to 2 TRX in No TX Div mode and to 1 TRX in TX Div mode. 1 · 1 · 248



Antenna coupling level The general functions performed at this level are: - Duplexing transmit and receive paths onto common antennas; - Feeding the received signals from the antenna to the receiver front end, where the signals are amplified and distributed to the different receivers (Low Noise Amplifier (LNA) and power splitter functions); - Providing filtering for the transmit and the receive paths; - Combining, if necessary, output signals of different transmitters and connecting them to the antenna(s); - Supervising antennas VSWR (Voltage Standing Wave Ratio). -Powering and supervising TMA through the feeder. The Antenna Network Combiner (ANC) module - one duplexer allowing a single antenna to be used for the transmission and reception of both downlink and uplink channels- hence minimizing the number of antenna - a frequency selective VSWR meter to monitor antenna feeder and antenna - one LNA amplifying the receive RF signal, and giving good VSWR values, noise compression and good reliability - two splitter levels distributing the received signal to four separate outputs so that each output receives the signal from its dedicated antenna and from the second one (diversity) - one Wide Band Combiner (WBC), concentrating two transmitter outputs into one, only for configurations with more than two TRX - insertion of 12V DC current in the feeder in order to provide power to TMAs when TMAs are used; there is thus no need for separate Power Distribution Unit (PDU) nor Bias-Tee (Feeder Lightning protections, that come with the ANC in case of outdoor BTSs, are themselves of a new type, compatible with this DC power feeding) (This function is only available with the new Evolution version of this module; it can be disabled, even if TMAs are used, in case those TMAs have their own PDUs).


2.9 Alcatel BSS

2.9.2 EVOLIUMTM A9100 Base Station (1) The Antenna network Combiner (ANc)- no-combining mode Antenna A TXA - RXA - RXdivB

Antenna B TXB- RXB - RXdivA

Duplexer

Duplexer

Filter Filter

Filter Filter

By- function

WBC

LNA

LNA

Splitter

Splitter

Splitter

Splitter

Splitter

Splitter

By- function

WBC

RXd RXn TX

TX RXn RXd

TRX 1

TRX 2

No-combining mode & No TX Div mode 1 · 1 · 249



The No-combining mode for configuration up to 2 TRX if TX Diversity is not used, or up to one TRX if TX Diversity is used (two TRX ports must then be connected to the two Antenna Connector ports of a same Twin TRX module); in these cases, the Wide Band Combiner is not needed, and therefore byed


2.9 Alcatel BSS

2.9.3 EVOLIUMTM A9100 Base Station (2) The Antenna network Combiner (ANc)- Combining mode & No TX Div mode Antenna A TXA - RXA - RXdivB

Antenna B TXB- RXB - RXdivA

Duplexer

Duplexer

Filter

W BC

Filter

Filter LNA

LNA

Splitter

Splitter

Splitter

Splitter

Splitter

TX RXn RXd

TX RXn RXd

RXdRXn TX

TRX 1

TRX 2

TRX 3

1 · 1 · 250

Splitter

Filter

W BC

RXd RXn TX TRX 4



The Combining mode for configuration from 3 up to 4 TRX if TX Diversity is not used, or up to 2 TRX if TX Diversity is used (two TRX ports must then be connected to the two Antenna Connector ports of a same Twin TRX module); in these cases, the Wide Band combiner is not byed, as shown in the figure


2.9 Alcatel BSS

2.9.4 EVOLIUMTM A9100 Base Station (3) The Twin Wide Band Combiner stage (ANY) combines up to four transmitters into two outputs, and distributes the two received signals up to four receivers. This module includes twice the same structure, each structure containing: ●one wide band combiner (WBC), concentrating two transmitter outputs into one ● two splitters, each one distributing the received signal to two separate outputs providing diversity and non-diversity path

ANy: Twin Wide Band Combiner Stage TXA

RXA

WBC

TX

RX

Splitter Splitter

RXdiv

TRX 1 1 · 1 · 251

RXAdiv

TX

RX

RXdiv

TRX 2

RXBdiv

RXB

TXB

Splitter Splitter

Rxdiv RX

TX

TRX 3

WBC

Rxdiv RX

TX

TRX 4




2.9 Alcatel BSS

2.9.5 EVOLIUMTM BTS Features Standard Features according to GSM DR (Dual Rate), EFR (Enhanced Full Rate coder), AMR (Adaptive Multi Rate) requires that the BSS software release and the other network elements also these codecs HW s GSM 850, E-GSM, GSM 900, GSM 1800 and GSM 1900 bands Multi Band Capabilities (ing of 850/1800 TRX, 850/1900TRX, and, 900 /1800 can be located in the same cabinet) All known A5 algorithms to be ed; HW provisions done

Standard Features due to new Architecture and new SW Releases SUS (Station Unit Sharing) Only one central control unit (SUM) for all BTS per cabinet Multiband BTS (GSM 900/1800) in one cabinet Static (Release 4) and statistical (Release 6) submultiplexing on Abis Better use of Abis-interface capacity: More BTS/TRX to be ed in a multidrop loop

Introduction of GPRS and HSCSD without HW changes EDGE compatible TRX

1 · 1 · 252



● The BTS range s A5/1 and A5/2 ciphering algorithms; ● A5/0 = ‘no ciphering’ is always ed. ● The TRX are hardware ready for A5/3.


2.9 Alcatel BSS

2.9.6 EVOLIUMTM BTS Features [cont.] Features specific to Radio Performance TX Output Power (at TRX output) TX output power, GMSK

TX output power, 8-PSK (EDGE)

GSM 850

Frequency band

45 W = 46.5 dBm

15 W = 41.8 dBm

GSM 900 MP (*)

45 W = 46.5 dBm

30 W = 44.8 dBm

GSM 900 HP

60 W = 47.8 dBm

30 W = 44.8 dBm

GSM 1800 MP (*)

35 W = 45.4 dBm

30 W = 44.8 dBm

GSM 1800 HP

60 W = 47.8 dBm

30 W = 44.8 dBm

GSM 1900

45 W = 46.5 dBm

25 W = 44.0 dBm

RX Sensitivity:

-111 dBm certified (GSM|ETSI| request: -104 dBm) Synthesized Frequency Hopping as general solution Standard RF hopping mode Pseudo baseband RF hopping mode

Antenna Diversity in general Two or four antennas (RX) per sector TX Diversity feature is possible with Twin TRX module in coverage mode only.

Duplexer (TX and RX on one antenna) as general solution Multiband capabilities Thanks to the high flexibility of the EVOLIUM™ A9100 Base Station, GSM 850 and GSM 1800 TRXs or GSM 850 and GSM 1900 TRXs or GSM 900 and GSM 1800 TRXs or GSM 900 and GSM 1900 TRXs can be located in the same cabinet with a single Station Unit Module (SUM). 1 · 1 · 253



(*) Note that for the Twin TRX, the TX output powers above are in capacity mode, i.e. each of the functional TRX achieves these output powers. In coverage mode, i.e. with Tx Diversity, a significant extra gain has to be considered (see "TX Diversity" chapter) thanks to on-air combining and diversity. ● The diagram below shows that 4RX Diversity requires two Antenna Network modules per sector, thereby

needing either 4 vertical-polarized or 2 cross-polarized antennas. TX1 RX1

TX2 RX3

RX2 0

A n te n n a N e tw o rk

RX4

A n te n n a N e tw o rk

TW IN TRX

Figure : Twin TRX module in TX Div & 4 RX div


2.9 Alcatel BSS

2.9.6 EVOLIUMTM BTS Features [cont.] Capacity Mode Principle 1 TWIN module = 2 functional TRX 1 Housing = 2 functional TRX = 16 radio timeslots Same Radio Performances as EDGE + TRX Medium Power

Tx Tx:: Rx Rx::

T R X

TRX TRX

TRX 1

TRX 2

GSM GSM 900 900 ::45 45W WGMSK GMSK//30 30W W8PSK 8PSK GSM 1800 : 35 W GMSK / 30 W 8PSK GSM 1800 : 35 W GMSK / 30 W 8PSK Sensitivity Sensitivity< <-114 -114dBm dBm

(-114 (-114toto-117 -117dBm dBmwith with22Rx Rxdiversity diversity––environment environmentdependent) dependent)

Reduced Power Consumption

Saving Savingper perTRX TRX(vs. (vs.TRX TRXEDGE+): EDGE+): --17 % in GSM 900 17 % in GSM 900 --35 35%%ininGSM GSM1800 1800 1 · 1 · 254




2 TRXs can belong to different sectors

2.9 Alcatel BSS

2.9.6 EVOLIUMTM BTS Features [cont.] Coverage Mode Principle Higher Output Power 1 TWIN module = 1 functional TRX = 8 radio TS 2 RX & 4 RX diversity possible TX diversity used ( very high coverage) Gain in sites (less sites needed) This mode is also called TX div mode Up to 12 TRX in MBI5/MBO2 cabinets

Higher Sensitivity

Tx Tx::

GSM GSM900 900::113 113to to175 175W W(*) (*)GMSK GMSK GSM 1800 : 88 to 136 W (*) GMSK GSM 1800 : 88 to 136 W (*) GMSK

Rx Rx::

Equ. Equ.sensitivity sensitivity= =-117.4 -117.4to to--121 121dBm dBm(*) (*)(4RX (4RXdiv) div) dependent) (*)(*) environment environment dependent)

1 · 1 · 255




2.9 Alcatel BSS

2.9.6 EVOLIUMTM BTS Features [cont.] 2 RX Diversity The TRX module s enhanced diversity combining in all frequency bands, which is based on several algorithms: A beam-forming algorithm to improve the received signal by steering a beam in the direction of the mobile. This is one way of doing smart antennas, An algorithm to reduce interference: this mitigates the influence of interferers by steering a null beam in the direction of the main interferer (the phase difference between the two antennas for the strongest interfering signal is estimated and then this interfering signal is strongly attenuated by summing the signals with an inversed phase). strong interferer

Environment

Total 2RX diversity gain

Equivalent RX sensitivity (without TMA)

Dense Urban (TU3)

6 dB

-117dBm

Sub Urban (TU50)

5 dB

-116dBm

Rural (RA100)

3.5 dB

-114.5dBm

1 · 1 · 256




2.9 Alcatel BSS

2.9.6 EVOLIUMTM BTS Features [cont.] 4 RX Diversity 4 RX diversity is ed by the Twin TRX module in coverage mode only. It uses exactly the same algorithms as for 2Rx diversity, i.e. beam-forming techniques are implemented. The table below provides the typical gains achieved thanks to 4RX enhanced Diversity and the equivalent Rx sensitivity that can be considered for link budget calculations.

Environment



Dense Urban (TU3)

10 dB

-121dBm

Sub Urban (TU50)

8.6 dB

-119.6dBm

Rural (RA100) 6.4 dB 4 RX diversity also provides significant benefits for-117.4dBm GPRS/EDGE since it allows achieving higher throughputs for given radio conditions.

1 · 1 · 257




2.9 Alcatel BSS

2.9.7 Generic Configurations for A9100 G4/5 BTS The configurations for indoor (MBI) and outdoor (MBO) cabinet are presented in the next slides larger configurations with more than one cabinet can be derived from the tables configurations are valid for EDGE capable TRX (Evolution step 2) availability of multiband configurations other than GSM 900 / GSM 1800 must be checked with product management (authorization required) Notation: BBU - Battery Backup Unit BATS - Small Battery Backup LBBU - Large Battery Backup Unit

1 · 1 · 258



TWIN TWIN TWIN TWIN

TRX

TRX

TRX

TRX

TWIN TWIN

S U M

A N C

TWIN TWIN A N Y

A N Y

A N C TRX

Indoor MBI5 3x8

TRX

TWIN TWIN A N Y

A N Y

A N C TRX

Available space for either: • Mounting Frame for 19" equipment (6U) • Battery

A N Y

A N Y TRX

TWIN TWIN

TRX

TWIN TWIN

TRX

A//DC conversion

TRX

TWIN TWIN A N Y TRX

A N C

TWIN TWIN

TRX

A N C

TRX

A N Y

TRX

A N Y TRX

A N C

TRX

A N Y


A N Y

S U M

TRX

TWIN TWIN A N Y TRX

TRX

Mounting Frame for 19" equipment (3U)

TWIN TWIN TWIN TWIN

TRX

TRX

TRX

TRX

Outdoor MBO2 3x8

Stand


2.9 Alcatel BSS

2.9.8 Non multi-band configurations Sectors

Min TRX

Max TRX per sector

per sect.

MBI3

AC

AC

BU5

other

Notes

MBI5 (Note 4)

DC

AC

AC

AC

BU90

BU5

Other

CBO

DC

AC

DC

MBO1 Evolut ion

MBO2 Evolut ion

Frequency bands

Standard(3) no TX div

1

1

8

8

8

8

8

8

8

4

6

8

8

900/1800

(2)


2

1

4

4

6

8

8

8

8

2

3

6

8

900/1800

(2)


3

1

2

2

4

4

4

6

8

1*

2

4

8

* No BU5

900/1800

(2)


4

1

2

2

4

4

4

6

2**

6

* No BU5 ** MBO1 Evo. only

900/1800

(2)

Low-loss no TX div

1

3

8

10

12

16

16

16

16

12

16

900/1800

(2)

Low-loss no TX div

2

3

3

4

6

8

10

10

12

6

12

900/1800

(2)

Low-loss no TX div

3

3

4

6

6

8

8

900/1800

(2)

Standard TX div & 2 RX div

1

1

4

4

4

4

4

4

4

2

2

4

4

900/1800

(2)


2

1

2

2

2

4

4

4

4

1

1

2

4

900/1800

(2)


3

1

1

2

2

2

2

2

2

1

2

2

900/1800

(2)

2

2

2

900/1800

(2)

2

2

900/1800

(2)

2

900/1800

(2)

Low loss TX div & 4 RX div

1

1

2

2

2

2

2

2

2


2

1

2

2

2

2

2

2

2


3

1

2

2

2

2

4

2

6

Note 1: "AC other" is referring to the Indoor AC configurations without integrated battery, i.e. either with no battery, or with batteries in an external cabinet. Note 2: Frequency bands: new modules are available initially in GSM 900 and GSM 1800 frequency band; they will be available in a second step in GSM 850 and GSM 1900, on market request. Note 3: As described in chapter "Standard configurations" above, "Standard" is referring to configurations with 1 Antenna Network per sector, and are thus limited to 8 TRXs per sector. Configurations with more than 8 TRXs per sector need two Antenna Networks per sector; such configurations are called "Low-loss" and described in a separate section of the table. Note 4: With MBI5, more than 18 TRX per cabinet is only possible with DC cabinets (and using TWIN modules) and more precisely with functional variant 3BK 25965 ABxx of these cabinets, that has become since end 2006 the standard delivery; MBI5 with functional variant 3BK 25965 AAxx, are limited to 18 TRX (using TWIN modules); functional variant of a cabinet can be checked either on site (on printed Barcode label, or available through Line Maintenance Terminal), or from the OMC-R where it is part of the Remote Inventory data.

1 · 1 · 259




2.9 Alcatel BSS

2.9.9 Multi-band configurations Sectors

Min TRX

(3)

per sect. band1/ band2

Standard no TX div

1

1/1

Standard no TX div

2

Standard no TX div

3

Max TRX per sector (band 1/ band 2)

MBI3

MBI5 (Note 4)

AC

AC

BU5

othe r

DC

2/2

2/2 6/6

AC BU90

AC

AC

Notes MBO1 Evolution MBO2 Evolution

CBO

DC

AC

DC

2/2

4/2

Frequency

bands

BU5 Other

8/8

8/8

8/8

12/12

1/1

4/4

4/4

4/4

6/6

1/1

2/2

2/2

2/2

4/4

6/6

12/12

900/1800

(2)

2/2

6/6

900/1800

(2)

4/4

900/1800

(2)

Note 1: "AC other" is referring to the Indoor AC configurations without integrated battery, i.e. either with no battery, or with batteries in an external cabinet. Note 2: Frequency bands: new modules are available initially in GSM 900 and GSM 1800 frequency band; they will be available in a second step in GSM 850 and GSM 1900, on market request. Note 3: Count of sectors is made with hypothese of multiband cell, i.e. that each sector contains one cell in band1 and one cell in band2, these two cells being paired as a single "multiband cell", counted as one sector. In multiband "without multiband cell", a same configurations would be counted as having twice the number of sectors. The table above thus describes at the same time - possible configurations for multiband "with multiband cell" - those configurations for multiband "without multiband cell" that have the same number of sectors in each band Note 4: With MBI5, more than 18 TRX per cabinet is only possible with DC cabinets (and using Twin TRX modules) and more precisely with functional variant 3BK 25965 ABxx of these cabinets, that has become since end 2006 the standard delivery; MBI5 with functional variant 3BK 25965 AAxx, are limited to 18 TRX (using Twin TRX modules); functional variant of a cabinet can be checked either on site (on printed Barcode label, or available through Line Maintenance Terminal), or from the OMC-R where it is part of the Remote Inventory data.

1 · 1 · 260




2.9 Alcatel BSS

2.9.10 Extended cell configurations

Min. Number

of TRX

Max. number

of TRX

Inner

Outer

Inner

Outer

Type of cabinet

Frequency band

1

1

8

8

MBI5; MBO2 evolution

900

1

1

4

4

MBI3; MBO1 Evolution

900

Extended Cell configurations

1 · 1 · 261




2.9 Alcatel BSS

2.9.11 Standard configurations The interface with the antenna system is through one single Antenna network combining (ANC) module in each sector (and then through 2 feeders and two antennas or one dual-polarized antenna). Antenna Antenna

Antenna Antenna

Antenna Antenna

Antenna Antenna

No-combining ANC or ANB

Combining ANC

Combining ANC

Combining ANC

TRX 1 TRX 2

TRX 1

TRX 4

TRX 1 TRX 2 Combiner (ANY) TRX 3

1 up to2TRX/ sector

3 up to 4TRX/ sector

Combiner (ANY)

TRX 6

5 up to 6TRX/ sector

TRX 1

TRX 4

Combiner (ANY) TRX 5

TRX 8

5 up to 8RX/sector

Standard configurations with Twin TRX in No TX Div

The number of sectors and TRXs depends on the cabinet type, with a maximum of 6 sectors and 24 TRXs in a Indoor MBI5 ("AB" functional variant) or an Outdoor MBO2 evolution cabinet. 1 · 1 · 262




2.9 Alcatel BSS

2.9.12 TRX Types Example of TRE boards with their frequency band and power characteristics NAME

BAND

POWER

GMSK

8PSK

W

dBm

W

dBm

TRAL

850

MP

45W

46,5

15W

41,8

TRAG

900

MP

45W

46,5

15W

41,8

TRAGE

900

MP

45W

46,5

30W

44,8

TAGH

900

HP

60W

47,7

25W

44,0

TAGHE

900

HP

60W

47,8

30W

41,8

TRAD

1800

MP

35W

45,4

12W

40,8

TRADE

1800

MP

35W

45,4

30W

44,8

TRAP

1900

MP

45W

46,5

25W

40,0

TRDH

1800

HP

60W

47,7

TADH

1800

HP

60W

47,7

25W

44,0

TADHE

1800

HP

60W

46,8

30W

44,8

TGT09

900

45W

46,5

30W

44,8

TGT18

1800

35W

45,4

30W

44,8

1 · 1 · 263



GMSK – Gaussian Minimum Shift Keying 8PSK – 8 phase shift keying TGT – Twin GSM Tranceiver Different Transceivers are used depending on the band : 900, 1800, 1900 (in America) and 850MHz (this new band has been introduced in the Release 1999 of the 3GPP Standard). The list above is not exhaustive. A new Tx Rx hardware module gives the possibility to have per Hardware module transmission receiption function. In this case the module is called Twin TRX For example In the MBI5 rack, the number of hardware module is 12 maximum, but if all are Twin TRX the maximum number of Transmitter functions will be 24. (TRE G5) The new Twin TRX (TGT) gives also the possibility to provide TX diversity


2.9 Alcatel BSS

2.9.12 TRX Types The losses between TRE connector and the Antenna connector

Configuration

Transmission loss (dB)

1 ANC without bridges

1.8

1 ANC

5.1

1 ANC + 1 ANY

8.6

1 ANX

1.8

1 ANX / 1 ANY

5.3

1 ANX + 2 ANY

8.8

delta ANY

3.5

1 · 1 · 264



Losses due to the Antenna Network (AN)

Module

Transmission loss (dB)

ANC

4.4

ANC no bridge

1

ANX

1

ANY

3.3

Radio cables TRE-AN

0.3

AN-AN

0.2

AN-Antenna

0.5


2.9 Alcatel BSS

2.9.13 BTS Output Power What is monitored during validation is the BTS output power at antenna connector The individual losses for duplexer, combiner and internal cabling are not systematically measured for detailed info consult the BTS product description

1 · 1 · 265




2.9 Alcatel BSS

2.9.14 Feature Power Balancing From G4 (now G5) BTS it is allowed to use TRXs of different power within the same sector, or to use of different combining path for TRX belonging to the same sector. Reason: the G4 BTS is able to detect unbalanced losses/powers within a sector and automatically compensate it for GMSK modulation. Consequence: All TRX connected to one ANc are automatically adjusted to the GMSK output power of the weakest TRX (required for BCCH recovery)

1 · 1 · 266




2.9 Alcatel BSS

2.9.15 Cell Split Feature Principle Cell Split allows to provide one logical cell with one common BCCH over several BTS cabinets. The cabinets must be synchronized

Benefits Same number of TRX in fewer racks No need to touch/modify the configuration of existing BTS (cabling) Take full benefit of 24 TRX per cabinet

Drawback: more complex antenna system Applications Multi-band cells Configuration extension of sites by adding TRX Large configurations

Condition: BTS must be synchronized

1 · 1 · 267



Configuration built with several cabinets and the “cell split over two BTSs” feature It is possible to optimize the number of cabinets needed for a site configuration (indoor or outdoor, single band or multi-band) built with more than one cabinet, thanks to a feature called “cell split over two BTSs”. In that case, the TRXs of one sector can be split over two A9100 BTS cabinets. Various configurations are possible, the only constraint being that following conditions are fulfilled: Maximal number of TRX per cell is 16. Maximal number of cabinets between which a given cell is shared is 2. Cabinets between which a cell is shared are clock synchronised in a master / slave configuration Note : when used in mono band configurations, cell split feature may allow to reduce the number of cabinets with regards to the solution with one cabinet per sector; but at the expense of a more complex antenna system (two ANC, hence 4 feeders per sector instead of 2 feeders, as for "low-loss" configurations); this has to be considered before selecting such a solution.


2.9 Alcatel BSS

2.9.19 Cell Split Example: High Power Configuration The following figure gives an example of standard multi-band with multi-band cell 3x8/3x8 in 2 MBI5 cabinets :

ANC

Cabinet1 (Standard 8,8,8TRX)

ANY TRX 1

ANC ANY

TRX 4

TRX 5

ANY TRX 8

TRX 1

ANY

Cabinet2 (Standard 8,8,8TRX)

TRX 1

TRX 4

TRX 5

ANY TRX 8

TRX 1

ANY TRX 5

ANY TRX 8

TRX 1

TRX 4

ANY

TRX 4

ANC

Sector1: 1x16 TRX

1 · 1 · 268

ANY

TRX 4

ANC

ANC

TRX 5

TRX 8

ANC ANY TRX 5

ANY TRX 8

Sector2: 1x16 TRX

TRX 1

TRX 4

ANY TRX 5

Sector3: 1x16 TRX



For a MBI5, in a 3 sector configuration, max. 3 HP TRX /sector are allowed (thermal reasons). The only way´to have 3x6 in MBI5 is with the cell split feature.


TRX 8

2.9 Alcatel BSS

2.9.22 Indoor BTS Rack Layout

1 · 1 · 269



IND mini: 4carrier, 1 Duplexer (Anx), 1 Combiner (Any), SUM (U, Link to BSC) IND Medi: 12carrier, 3 Duplexer (Anx), 3 Combiner (Any), SUM (U, Link to BSC)


2.9 Alcatel BSS

MBO1 Evolution

MBO2 Evolution

Depth (floor level)

74 cm

74 cm

Depth (roof level)

80 cm

80 cm

Height without plintht

146 cm

146 cm

Height with plinth

161 cm

161 cm

Width

94 cm

156 cm


External Dimensions


2.9.23 Outdoor MBO1 Evolution and MBO2 Evolution cabinets

Radio subrack

Radio subrack

Radio subrack

Radio subrack

Radio subrack

Radio subrack

A//DC conversion

Mounting Frame for 19" equipment (3U)

The Multi-standard Outdoor BaseStation cabinets MBO1 Evolution and MBO2 Evolution offer operators important flexibility with: An easy extension on-site from the Outdoor MBO1 Evolution BTS (up to 12 TRXs capacity) to the Outdoor MBO2 Evolution BTS (up to 24 TRXs capacity)

1 · 1 · 270




2.9 Alcatel BSS

2.9.24 Micro BTS types M5M EVOLIUM A9110 Micro-BTS (M5M) Introduced in Q3 2003 up to 12 TRX-es site configurations can mix older A910 with newer A9110-E for GPRS and EDGE (release dependent)

1 · 1 · 271



13 All Rights Reserved © Alcatel-Lucent 2010 TMO54014 Issue 01

2.9 Alcatel BSS

2.9.25 Technical Data

A910 A9110 (2 TRX) (2 TRX) GSM 850, E-GSM, GSM 850, E-GSM, GSM900, GSM 1800, GSM GSM900, GSM 1800, GSM 1900 1900 Up to 4.5 W 7W

Frequency band Tx output power (at antenna connector) Rx sensitivity

-107 dBm

-110 dBm

Yes

yes

Temperature range (max.)

55 °C

55 °C

Max. power consumption

130 W

145 W

Size (volume)

54 litres

54 litres

39.6 kg (incl. connection box)

32.5

Radio FH

Weight

1 · 1 · 272




2.9 Alcatel BSS

2.9.26 BSC capacities in of boards Three BSC capacities are defined depending on the number of TRXs BSC Capacity Equipment

200 TRX 400 TRX 600 TRX

ATCA shelf

1

C

1

2

Spare C

1

TPGSM

2

OM

2

SSW

2

LIU shelf

1

MUX

2

LIU

1 · 1 · 273

8

3

16



The quantity of TPGSM, OM, SSW and MUX boards have to be considered as 1 activ + 1 stand-by for redundancy function in the shelf. LIU Line Interface Unit – 16x 2Mbit/Board


2.9 Alcatel BSS

2.9.27 Capacity and dimensioning for E1 links The BSC Evolution is able to process up to 2600 erlangs BSC Capacity Equipment

200 TRX 400 TRX 600 TRX

Max number of BTS

150

255

255

Max number of cells

200

264

264

Total number of E1

112

128

224

Number of Abis

96

96

176

Number of Atermux CS

10

20

30

Number of Atermux PS

6

12

18

900 Traffic Ater PS (Mb/s) Max12

1800

2600

24

36

Number of Erlangs

1 · 1 · 274




2.9 Alcatel BSS

2.9.28 Abis and atermux allocation on LIU boards

LIU 8 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128

One ater LIU board for 200 TRX

400

LIU 7 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112

400

LIU 6 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96

600 TRX 400 TRX 200 TRX LIU 9 LIU 10 LIU 11 LIU 12 LIU 13 LIU 14 LIU 15 LIU 16 129 145 161 41 31 21 2 1 130 145 162 42 32 22 4 3 131 147 163 43 33 23 6 5 132 148 164 44 34 24 8 7 133 149 165 45 35 25 10 9 134 150 166 46 36 26 12 11 135 151 167 47 37 27 14 13 136 152 168 48 38 28 16 15 137 153 169 x 39 29 18 17 138 154 170 x 40 30 20 19 139 155 171 x 24 18 12 11 140 156 172 x 23 17 10 9 141 157 173 28 22 16 8 7 142 158 174 27 21 15 6 5 143 159 175 26 20 14 4 3 144 160 176 25 19 13 2 1

200

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16

600 TRX 400 TRX 200 TRX LIU 1 LIU 2 LIU 3 LIU 4 LIU 5 1 17 33 49 65 2 18 34 50 66 3 19 35 51 67 4 20 36 52 68 5 21 37 53 69 6 22 38 54 70 7 23 39 55 71 8 24 40 56 72 9 25 41 57 73 10 26 42 58 74 11 27 43 59 75 12 28 44 60 76 13 29 45 61 77 14 30 46 62 78 15 31 47 63 79 16 32 48 64 80

200

Abis and atermux allocation on LIU boards versus BSC capacity

Maximum flexibility on abis LIU board

Ater Ports

Abis ports

Abis ports (max 176) Atermux CS (max 48) Ater mux PS (max 28)

1 · 1 · 275



LIU boards are fitted in the LIU shelf depending on the BSC configuration (Capacity + connectivity), but only 2 HW configurations for the LIU shelf are considered: one with 8 LIU boards, one with 16 LIU boards, Assignment to each LIU boards either to Abis or Ater, On the Ater LIU, 10 TP are “generic” (can be assigned either to PS, full CS or a mixed of the 2), and the 6 others are dedicated to PS. In case of 200 TRX configuration, Alcatel decided to split the traffic up to 2 LIU boards (even if one LIU board should be efficient) in order to not impact all the traffic in case of one LIU board failure. The maximum of available LIU boards are used for Abis, to offer maximum flexibility to the clients. The port numbered 9, 10, 11 and 12 on the LIU 12 are not used.


2 Coverage Planning

2.10 Coveradge Improvement

1 · 1 · 276




2.10 Coveradge Improvement

2.10.1 Antenna Diversity

1 · 1 · 277





2.10.1.1 Diversity Purpose

Demands

Improvement in fading probability statistics leads to a better total signal level or better total S/N ratio

Principle Combining signals with same information from different signal branches

1 · 1 · 278

correlation between different signal branches should be low

Combining methods Selection Diversity Maximum Ratio Combining Equal Gain Combining



Purpose The purpose of using diversity is to reduce short-term fading effects, such that an acceptable level of performance (receiver sensitivity) can be achieved, without having to increase the transmitted power or the bandwidth. Principle The principle relies on the combination of two or more signals, containing the same information, which are at least partially de-correlated. If two signals of the same level are completely de-correlated, the probability that both signals experience the same depth of fade is very low. Therefore the signal reliability is increased.



2.10.1.2 Selection Diversity (1)

Fieldstrength [dBm]

Principle selection of the highest baseband signal-to-noise ratio (S/N) or of the strongest signal (S+N) -80

Correlation of signal levels a lower correlation between signal levels of different branches improves the total signal level

-90

Correlation of signal levels should be low

-100 Antenna 1 Antenna 2

0.1

0.2

0.3

0.4

Time [sec]

1 · 1 · 279



The algorithm for the selective diversity combining technique is based on the principle of selecting the best signal among all of the signals received from different branches, at the receiving end.



2.10.1.3 Selection Diversity (2) Difference in signal level

Fieldstrength [dBm]

a high difference in signal levels of two branches doesn’t improve the total signal level

Difference in signal levels should be low

-80

-90

-100 Antenna 2

Antenna 1

0.1

0.2

Time [sec]

1 · 1 · 280

0.3

0.4





2.10.1.4 Selection Diversity (3) Theoretical diversity gain 10dB for two-branch diversity at the 99% reliability level 16dB for four branches at the 99% reliability level

The theoretical diversity gain doesn’t improve linear with the number of branches

1 · 1 · 281





2.10.1.5 Equal Gain Combining (1) Principle cophase signal branches sum up signals

Coherent addition of signals and incoherent addition of noises Theoretical diversity gain 11dB for two-branch diversity at the 99% reliability level

1 · 1 · 282



In comparison with MRC, in this technique the branch weights are all set to unity but the signal from each branch are co-phased to provide equal gain combining diversity. The possibility of producing an acceptable signal from a number of unacceptable inputs is still retained, and performance is only marginally inferior to maximal ratio combining an superior to selection diversity.



2.10.1.6 Equal Gain Combining (2) Correlation of signal levels

Difference in signal level

a lower correlation between signal levels of different branches improves the total S/N ratio


1 · 1 · 283

Assuming equal noise in the branches, the higher the difference in signal levels is, the higher is the loss of S/N ratio of the better signal branch after summation

Difference in signal levels should be low





2.10.1.7 Maximum Ratio Combining (1) Principle weight signals proportionally to their S/N ratios cophase signal branches sum up the weighted signals

Coherent addition of signals and incoherent addition of noises Improved S/N

1 · 1 · 284



In this method the signals from all the branches are weighted according to their individual S/N and then summed. Here the individual signals must be co-phased before being summed ( unlike selection diversity ) which generally requires an individual receiver and phasing circuit for each antenna . Maximal ratio combining produces an output SNR equal to the sum of the individual SNRs. Thus, it has the advantage of producing an output with an acceptable SNR even when none of the individual signals are themselves acceptable. This technique gives the best statistical reduction of fading of any known diversity combiner. Modern DSPs and digital receivers are now making this optimal form of diversity practical.



2.10.1.8 Maximum Ratio Combining (2) Correlation of signal levels

Difference in signal level

a lower correlation between signal levels of different branches improves the total S/N ratio

Assuming equal noise in the branches, the higher the difference in signal levels is, the higher is the loss of S/N ratio of the better signal branch after summation comparing to equal ratio combining, this combining reduces influence of worse signal branches


low

1 · 1 · 285

Difference in signal levels should be





2.10.1.9 Comparison of combining methods Improvement of average SNR from a diversity combiner compared to one branch (a) Maximum Ratio Combining (b) Equal Gain Combining (c) Selection Diversity

The maximum ratio combining, which is used in the ALCATEL BTS, gives the best statistical reduction of any known linear diversity combiner.

1 · 1 · 286





2.10.1.10 Enhanced Diversity Combining (1) Principle: 2 algorithms Beam forming algorithm (available also for MRC) Interference reduction algorithm (new)

best efficiency when the useful signal and the interfering signals come from different directions.

Requirements to benefit from this feature: Hardware: G4 (onwards) TRE (Edge capable TRX) installed in Evolium Evolution BTS step1 resp. step 2 (internal name: G3 resp. G4) Software release: from B6.2 onwards For a maximum gain: antenna engineering rules respected Correct antenna choice for the considered environment Correct antenna spacings and orientations (in case of space diversity)

1 · 1 · 287



The TRX module s enhanced diversity combining in all frequency bands, which is based on several algorithms: ●

A beam-forming algorithm to improve the received signal by steering a beam in the direction of the mobile. This is one way of doing smart antennas,

●

An algorithm to reduce interference: this mitigates the influence of interferers by steering a null beam in the direction of the main interferer (the phase difference between the two antennas for the strongest interfering signal is estimated and then this interfering signal is strongly attenuated by summing the signals with an inversed phase).

Maximum efficiency of enhanced diversity combining is achieved when the useful/desired signal and the interfering signals emanate from different directions. In interference-limited environments, beam-forming algorithms will provide a much greater diversity gain compared to traditional maximum ratio combining. ●

The above mentioned algorithms are working together in a way to combat spatial interferer signals while keeping optimal sensitivity perfomance for undisturbed but week reception.



2.10.1.11 Enhanced Diversity Combining (2)

Diversity gain coming from the fact that the signals received on both antennas are decorrelated (this requires using Xpol antennas or largely spaced antennas) Array-Gain or Beamforming gain : coming from the fact, that co-phased signals are added (stronger combined signal power) for this direction Null Steering / Interference Reduction (with a spatial interferer) coming from a algorithm which reduces the interference (the figures below assume a standard interference margin is considered for the link budget)

Environment



Dense Urban (TU3)

6 dB

-117dBm

Sub Urban (TU50)

5 dB

-116dBm

Rural (RA100)

3.5 dB

-114.5dBm

1 · 1 · 288





2.10.1.12 Tx Diversity Basic Idea: Transmit twice the same signal from two antennas No combining losses (on air combining) 3dB gain Possible Issue: Coherence between signal can lead to destructive effects This effect depends on the environment a short delay is introduced between two antennas (2 symbols) Environment

Total TX diversity gain

Equivalent TX output power (GMSK)

Dense Urban (TU3)

5.9 dB

GSM900: 52.4dBm (175W) GSM1800: 51.3dBm (136W)

Sub Urban (TU50)

4.6 dB

GSM900: 51.1dBm (129W) GSM1800: 50dBm (100W)

Rural (RA100)

4 dB

GSM900: 50.5dBm (113W) GSM1800: 49.4dBm (88W)

BTS

MS

0011000101001

0011000101001 short delay

1 · 1 · 289



TX Diversity works with all types of Mobile stations since it is fully transparent to the receiver; this feature takes advantage of the MS equalizer which can already handle multiple paths with different times of arrival. Consequently, the equivalent TX output power is very high, up to 6dB above the nominal TX output power, which improves the coverage and reduces the number of sites needed to cover a given area, provided the link budget remains balanced or downlink-limited The table provides the typical gains achieved thanks to TX Diversity and the equivalent TX output power that can be considered for link budget calculations. Note that such gains are environment-dependent since they are highly related to the level of de-correlation between paths. In 8-PSK, the TX diversity gain is highly dependent on the coding scheme, the environment and the level of Carrier to Interference+Noise Ratio. No significant gains are expected.



2.10.1.12 Tx Diversity

Diversity Gain: On top of the output power increase TxDiv artificially increases the number of multi-paths The higher the de-correlation between paths, the higher the gain Other features: a) high power TRX or b) Transmit Coherent Combining do not benefit from this effect Time

Example:

First channel

Fading hole

2 paths (blue and red) They show independent amplitude (fast) fading Probability to fall in a hole is reduced Fading holes of a channel are often compensated by the other channel

Second channel

Attenuation

Additional gain 1 · 1 · 290






Delay Trade-Off Higher delay between antennas implies Less destructive effect, more de-correlated paths and so higher diversity gain: Higher Gains Higher channel delay spread: More Self-interference

Alcatel found the optimal trade-off • For all environments • Based on extensive simulations and lab measurements

1 · 1 · 291




0011000101001

0011000101001 short delay



Summary of the Transmit Diversity effects 3dB increase of the signal strength Additional up to 2.9dB diversity gain for un-correlated fast fading: Diversity gains are maximum in dense urban because there are a lot of scatterers Diversity gains are reduced in rural because we have Line of Sight propagation

Self-interference due to the artificial increase of the delay spread Environment

Fading Profile

Power increase

Diversity gain

Total TxDiv gain

Dense Urban

TU3

3dB

2.9dB

5.9dB

Sub-Urban

TU50

3dB

1.6dB

4.6dB

Rural

RA100

3dB

1dB

4dB

1 · 1 · 292





2.10.1.12 Diversity systems in Mobile Radio Networks Two diversity systems are used in Mobile Radio Networks : Space Diversity

TXB

horizontal vertical

dH

dH

RXA

RXB

TXA

TXB dv TXA

Polarization Diversity

+45°

-45°

+45°

RXA RXB 1 · 1 · 293

-45°

TXA TXB All Rights Reserved © Alcatel-Lucent 2010




2.10.1.13 Space Diversity Systems

Diversity gain depends on spatial separation of antennas Horizontal separation (e.g. Roof Top)

Vertical separation (e.g. Mast) RXA dV

dH RXA

RXB

RXB

For Optimum Diversity Gain dH = 20λ 15λ GSM900 = 6m GSM1800 = 3m 1 · 1 · 294

dV GSM900 GSM1800 All Rights Reserved © Alcatel-Lucent 2010



= = 4.5m = 2.25m


2.10.1.14 Space Diversity - General Rules The larger the separation the higher the diversity gain Prefer horizontal separation (more effective) d The higher the antenna the higher the required separation, rule: d > h/10 h Highest diversity gain from the "broadside” Select orientation of diversity setup according to orientation of cell / traffic

Optimum diversity Gain

1 · 1 · 295





2.10.1.15 Achievable Diversity Gain Depends on fading conditions Varies in between 2.5 - 6dB Higher diversity gain in areas with multipath propagation (urban and suburban areas)

General rule: consider diversity gain with 3dB in the link budget

1 · 1 · 296





2.10.1.16 Polarization Diversity Diversity gain in using orthogonal orientated antennas

Horizontal / vertical polarization: Hor/Ver Antenna

V

H

RXA RXB

Polarization of +/- 45°: cross polarized antenna or Slant antenna

+45° 45° RXA RXB

Big Advantage: Only one antenna is required to profit from diversity gain using this configuration 1 · 1 · 297





2.10.1.17 Principle of Polarization Diversity

multipathpropagation reflection, diffraction

1 · 1 · 298

reception with a hor / ver polarised antenna

EV

Diversity Gain

EH

G = f( ρ,Δ )

EX1 Ex2 or Eh

reception with a X-polarised antenna

EX2

Ex1 or Ev

Time [sec]



ρ correlation coeficient (0.7) Δ difference in signal level ---> diversity gain with dual polarized antennas depends on : ρ, Δ and the orientation of the sending and receiving antenna To achieve low correlation and low differences in signal level, reflection and diffraction under multipath condition is necessary. ----> In rural areas neglectible diversity gain can be expected from polarization diversity.



2.10.1.18 Air Combining Features only one TX per antenna combining signals "on air" and not in a combiner 3dB combiner loss can be saved to increase coverage

Can be realized with two vertical polarized antennas one cross polarized antenna

TX1 TX2

TX1

TX2

1 · 1 · 299



The idea of air combining is to combine transmitted signals in the air and not with an internal combiner, in order to save combining losses. Thus the maximum achievable coverage range will be increased. Air combining can be realized with • two sector or omni antennas • one cross polar antenna transmitting different carriers on +/-45°.



2.10.1.19 Air Combining with Polarization Diversity One antenna system

1 TRX

2 TRX

cross polarized antennas recommended for urban/suburban area (less space req.)

or

V DUPL TX RXA

H BF RXB

No Air combining Bandfilter if Decoupling too low

1 · 1 · 300

DUPL

DUPL

TX1 RX1 TX2 RX2 RX2D RX1D Air combining Recommended for Evolium BTS





2.10.1.20 Air Combining with Space Diversity Two antenna system Vertical or horizontal spacing (recommended for rural area)

or

or RXA RXB

RXA RXB TX TX

1 · 1 · 301





2.10.1.21 Decoupling of Signal Branches

One antenna system: TX / RX decoupling cannot be achieved by spatial separation Decoupling between both polarization branches needs to be sufficiently high to avoid blocking problems intermodulation problems

Required decoupling values G2 BTS: Evolium A9100 BTS:

1 · 1 · 302

30 dB 25dB (Integrated duplexer Anx)





2.10.1.22 Cross Polarized or Hor/Ver Antenna? (1) Receiving Application same diversity gain for cross polarized and hor/ver antennas in urban and suburban area polarization diversity gain equal to space diversity gain (2.5 - 6dB) negligible polarization diversity gain in rural areas (not recommended) accordingly consider polarization diversity gain with 3dB in the link budget

1 · 1 · 303





2.10.1.23 Cross Polarized or Hor/Ver Antenna? (2) Transmission Application: Air combining

3dB

1 · 1 · 304

2dB

3dB loss when transmitting horizontal/vertical polarized (use of combiner) 1-2dB losses when transmitting at 45° (optimum antenna is straighten vertically) Air combining only recommended with cross polarized antenna





2.10.1.24 Conclusion on Antenna Diversity Rural Areas installation space not limited apply Space Diversity (higher gain)

Urban and Suburban Area apply space or polarization diversity use cross polarized antennas for air combining

Diversity Gain consider diversity gain in link budget with 3dB

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2.10. Coveradge Improvement

2.10.2 Repeater Systems

1 · 1 · 306





2.10.2.1 Repeater Application

repeater

area covered by repeater

1 · 1 · 307

BTS (donor cell)

original service area





2.10.2.2 Repeater Block Diagram

Required Isolation > 70…90 dB

1 · 1 · 308



A repeater is a bi-directional amplifier. It receives the downlink signal from the BTS, amplifies it and transmits the signal to the mobile. In the uplink direction, the signal of the mobile is received, amplified and transmitted to the BTS.



2.10.2.3 Repeater Applications (2) Coverage Improvement of Cells (‘Cell Enhancer’) removal of coverage holes caused by topography (hills, ravines, ...) man made obstacles

Provision of tunnel coverage street, railway tunnels underground stations

Provision of indoor coverage at places of low additional traffic

1 · 1 · 309





2.10.2.4 Repeater Types Channel selective repeaters

Broad band repeaters

high selectivity of certain channels high traffic areas, small cell sizes

Band selective repeaters adjustment to operator’s frequency band no (accidental) usage by competitors

1 · 1 · 310

low cost solution for low traffic areas (rural environment) medium to high repeater gain

Personal repeaters low gain broad band indoor coverage improvement for certain rooms





2.10.2.5 Repeater for Tunnel Coverage Choice of repeater type due to tunnel dimensions wall materials

Antenna to donor cell

feeding by directional antennas leaky feeder cables

long tunnels Radiating cable Repeater

chains of several repeaters fiber optic backbone for repeater feeding

Tunnel

1 · 1 · 311





2.10.2.4 Repeater for Indoor coverage For smaller buildings Compensation for wall losses, window losses (heat insulated windows) Low cost personal repeaters installed in certain rooms

Personal repeater

For larger buildings (shopping malls, convention centers, sport centers) multispot transmission using co-axial distribution network fiber-optic distribution network

Antenna to donor cell Master unit

Remote units

Fiber optic distribution Radiating cable

1 · 1 · 312





2.10.2.5 Planning Aspects Repeater does not provide additional traffic capacity risk of blocking if additional coverage area catches more traffic possible carrier upgrading required

Repeater causes additional signal delay delay: 4..8μs ⌫ max. cell range of 35 km reduced by 1 to 2km special care needed for total delay of repeater chain! delayed signal and original signal could cause outage in urban environment if total delay exceeds 16 ... 22μs

1 · 1 · 313





2.10.2.6 Repeater Gain Limitation (1) Intermodulation products should be low when amplifier reaches saturation point, intermodulation products go up

Signal to noise ratio should be high when amplifier reaches saturation point, signal to noise ratio is getting worse

Antenna isolation between transmission and receiving antenna should be high if signal from transmission antenna to receiving antenna is too high, amplifier goes into saturation

1 · 1 · 314





2.10.2.7 Repeater Gain Limitation (2)

Repeater gain limited by antenna isolation: GRepeater < IDonor, Repeater - M Pin

Pback = Pin - 12 dB

M (Margin) ~ 12 dB gain 78 dB

isolation 90 dB

Measure isolation after installation

1 · 1 · 315



I = G Amplifier + δ M arg in


Pout


2.10.2.8 Intermodulation Products

A Non-linear system produces higher-order intermodulation products as soon as output power reaches the saturation point

Parameter 1 dB compression point 3rd order intercept point (I3) Intermodulation reduction (IMR) Amplifier back-off

GSM900/GSM1800 requirements IM products ≤ -36 dBm or IM distance > 70 dBc whichever is higher

1 · 1 · 316



Each amplifier has a limited linear operation range. In the linear range the input power is amplified by the amplification factor v. But this is only valid until a certain maximum input power. As soon as you feed the amplifier with too high input power the input signal will less and less amplified. The point were the degradation from the specified amplification is 1dB is called the one dB compression point. Lower amplification is one effect when you operate an amplifier in the non linear region, another effect which can cause even worse problems is the intermodulation. Especially the 3rd order intermodulation product (2f1+-f2) is very significant. The amplifier produces interfering signals based on available frequencies (f1 and f2). dbc = is the power of one signal referenced to a carrier signal



2.10.2.9 Repeater Link Budget !

!

Uplink Loss = Downlink Loss ⇒ Uplink Gain = Downlink Gain Downlink Path Received power at repeater Link antenna gain Cable loss Repeater input power Repeater gain Repeater output power Cable loss Repeater antenna gain EIRP

Unit dBm dBi dB dBm dB dBm dB dBi dBm

Value -65 +19 -2 -48 +78 30 -2 +18 46

Different gains may be needed in Up- and Downlink if the sensitivity of the repeater is worse than the sensitivity of the BTS

1 · 1 · 317





2.10.2.10 High Power TRXs High Power TRXs: solution for coverage improvement HP must be used together with TMA: due to unbalanced Link Budget A9100 BTS s High Power TRX Medium Power TRX type is chosen by: environment conditions required data throughput (GPRS/EDGE)

TX power of EVOLIUM™ Evolution step 2 TRX : Frequency band

TX output power, GMSK

TX output power, 8-PSK (EDGE)

GSM 900 HP

60 W = 47.8 dBm

25 W = 44.0 dBm

GSM 1800 HP

60 W = 47.8 dBm

25 W = 44.0 dBm

1 · 1 · 318





2.10.2.13 3x6 TRXs High Power Configuration Configuration made with EVOLIUM™ A9100 Base Station Obs: All TRX are HP The configuration is using cell split feature

ANc Combining

Cabinet1 (High power 3x3TRX)

No-combining

HPTRX1 HPTRX 2 MPTRX 3

Cabinet2 (High power 3x3TRX)

ANc Combining


ANc Combining

No-combining


Sector1: 1x6 TRX

1 · 1 · 319

No-combining

ANc Combining


ANc Combining

No-combining


Sector2: 1x6 TRX

No-combining

ANc Combining

No-combining


Sector3: 1x6 TRX





2.10.2.14 Mixed TRX Configuration

BTS EVOLIUM™ s a mix of: EVOLIUM™ TRX (TRE) - s GSM/GPRS and EDGE EVOLIUM™ Evolution step 2 TRX (TRA) with Medium Power EVOLIUM™ Evolution step 2 TRX (TRA) with High Power Hardware configuration

T R A

T R A

HP

MP

T R E

T R E

Logical cell

Allocation Packet Voice

TRX1 (BCCH) TRX2 (1 SDCCH) TRX3 TRX4

1 · 1 · 320




3 Traffic & Frequency Planning

1 · 1 · 321




3 Fraffic & Frequency Planning

3.1 Traffic Caspacity

1 · 1 · 322




3.1 Traffic Capacity

3.1.1 Telephone System blocked call attempts

subscriber sub 1

1 2

line to PSTN

3 4

sub 2 sub 3 sub 4

automatic switch

observation period, e.g. main busy hour (MBH)

Parameters: λ: μ: 1/μ:

arrival rate [1/h] release rate [1/h] mean holding time [sec]

1 · 1 · 323

time

"offered" traffic = # of calls arriving in MBH × mean holding time ρ = λ × 1/μ [Erlang]





3.1.2 Offered Traffic and Traffic Capacity

Offered Traffic (ρ)

Loss System (n slots)

Handled Traffic (T) T=ρ-R

Rejected Traffic (R)

Handled Traffic, Traffic Capacity: T Blocking Probability, Grade of Service (GoS): pblock = R / ρ System load: τ = T / n, i.e. T < n

1 · 1 · 324





3.1.3 Definition of Erlang

ERLANG : Unit used to quantify traffic

T=

(resource usage duration)/ (total observation duration)

1 · 1 · 325




[ERLANG]


3.1.4 Call Mix and Erlang Calculation

CALL MIX EXAMPLE 350 call/hour 3 LU/call TCH duration : 85 sec SDCCH duration : 4,5 sec

ERLANG COMPUTATION TCH = (350 * 85)/3600 = 8,26 ERLANG SDCCH = [ (350 + 350*3) * 4,5 ] / 3600 = 1.75 ERLANG

1 · 1 · 326





3.1.5 ERLANG B LAW

ERLANG B LAW Relationship between Offered traffic Number of resources Blocking rate

1 · 1 · 327





3.1.5 ERLANG B LAW (2)

call request arrival rate (and leaving) is not stable number of resources = average number of requests mean duration is sometime not sufficent => probability of blocking

=> Erlang B law Pblock : blocking probability N : number of resources E : offered traffic [Erlang] Calculated with Excel - Makro or Table

1 · 1 · 328





3.1.6 Erlang´s Formula How to calculate the traffic capacity T? Basics: Markov Chain (queue statistics) λ

λ

p0

p1 μ

p2 2μ

no call establishe d

pi

pn nμ

3μ

i channels occupied

all channels occupied

Calculation of the blocking probability using Erlang´s formula (Erlang B statistics):

n ρi ρn p block = ∑ n ! i = 0 i! Varation of ρ until pblock reached: ρ → T

1 · 1 · 329





3.1.7 Blocking Probability (Erlang B)

Nr. of channels 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 30 35 40 45 50

Blocking Probability Erlang B 0.1% 0.2% 0.5% 0.001 0.046 0.194 0.439 0.762 1.146 1.579 2.051 2.557 3.092 3.651 4.231 4.831 5.446 6.077 6.721 7.378 8.046 8.724 9.411 10.108 10.812 11.524 12.243 12.969 16.684 20.517 24.444 28.447 32.512

0.002 0.065 0.249 0.535 0.900 1.325 1.798 2.311 2.855 3.427 4.022 4.637 5.270 5.919 6.582 7.258 7.946 8.644 9.351 10.068 10.793 11.525 12.265 13.011 13.763 17.606 21.559 25.599 29.708 33.876

1 · 1 · 330

0.005 0.105 0.349 0.701 1.132 1.622 2.157 2.730 3.333 3.961 4.610 5.279 5.964 6.663 7.376 8.099 8.834 9.578 10.331 11.092 11.860 12.635 13.416 14.204 14.997 19.034 23.169 27.382 31.656 35.982

1%

2%

3%

4%

5%

10%

15%

20%

50%

0.010 0.153 0.455 0.869 1.361 1.909 2.501 3.128 3.783 4.461 5.160 5.876 6.607 7.352 8.108 8.875 9.652 10.437 11.230 12.031 12.838 13.651 14.470 15.295 16.125 20.337 24.638 29.007 33.432 37.901

0.020 0.223 0.602 1.092 1.657 2.276 2.935 3.627 4.345 5.084 5.842 6.615 7.402 8.200 9.010 9.828 10.656 11.491 12.333 13.182 14.036 14.896 15.761 16.631 17.505 21.932 26.435 30.997 35.607 40.255

0.031 0.282 0.715 1.259 1.875 2.543 3.250 3.987 4.748 5.529 6.328 7.141 7.967 8.803 9.650 10.505 11.368 12.238 13.115 13.997 14.885 15.778 16.675 17.577 18.483 23.062 27.711 32.412 37.155 41.933

0.042 0.333 0.812 1.399 2.057 2.765 3.509 4.283 5.080 5.895 6.727 7.573 8.430 9.298 10.174 11.059 11.952 12.850 13.755 14.665 15.581 16.500 17.425 18.353 19.284 23.990 28.758 33.575 38.430 43.316

0.053 0.381 0.899 1.525 2.218 2.960 3.738 4.543 5.370 6.216 7.076 7.950 8.835 9.730 10.633 11.544 12.461 13.385 14.315 15.249 16.189 17.132 18.080 19.031 19.985 24.802 29.677 34.596 39.550 44.533

0.111 0.595 1.271 2.045 2.881 3.758 4.666 5.597 6.546 7.511 8.487 9.474 10.470 11.473 12.484 13.500 14.522 15.548 16.579 17.613 18.651 19.692 20.737 21.784 22.833 28.113 33.434 38.787 44.165 49.562

0.176 0.796 1.602 2.501 3.454 4.445 5.461 6.498 7.551 8.616 9.691 10.776 11.867 12.965 14.068 15.176 16.289 17.405 18.525 19.647 20.773 21.901 23.031 24.164 25.298 30.995 36.723 42.475 48.245 54.029

0.250 1.000 1.930 2.945 4.010 5.109 6.230 7.369 8.522 9.685 10.857 12.036 13.222 14.413 15.608 16.807 18.010 19.216 20.424 21.635 22.848 24.064 25.281 26.499 27.720 33.840 39.985 46.147 52.322 58.508

1.000 2.732 4.591 6.501 8.437 10.389 12.351 14.320 16.294 18.273 20.254 22.238 24.224 26.212 28.201 30.191 32.182 34.173 36.166 38.159 40.153 42.147 44.142 46.137 48.132 58.113 68.099 78.088 88.079 98.072





3.1.8 BTS Traffic Capacity (Full Rate)

Number of TRX SDCCH 1 4 2 8 3 8 4 16 5 16 6 24 7 24 8 32

TCH 7 14 22 29 37 44 52 59

1 · 1 · 331

Speech Traffic (Erlang 1% 2% 2.501 2.935 7.352 8.2 13.651 14.896 19.487 21.039 26.379 28.254 32.543 34.682 39.7 42.124 46.039 48.7

B) 5% 3.738 9.73 17.132 23.833 31.64 38.557 46.533 53.559

Signalling Traffic (Erlang B) 0.1% 0.2% 0.5% 0.439 0.535 0.701 2.051 2.311 2.73 2.051 2.311 2.73 6.721 7.258 8.099 6.721 7.258 8.099 12.243 13.011 14.204 12.243 13.011 14.204 18.205 19.176 20.678





3.2 Network Evolution

1 · 1 · 332





3.2.1 Network Evolution - Capacity Approach (1) The roll out of a network is dedicated to provide coverage Network design changes rapidly Planning method must be flexible and fast (group method) Manual frequency planning possible

1 · 1 · 333





3.2.2 Network Evolution - Capacity Approach (2) With the growing amount of subscribers, the need for more installed capacity is rising Possible Solutions: Installing more TRXs on the existing BTS Implementing additional sites

Discussion!

1 · 1 · 334



Also new services like GPRS are demanding more capacity



3.2.3 Network Evolution - Capacity Approach (3) Installing more TRXs - Advantages No site search/acquisition process No additional sites to rent (saves cost) Trunking efficiency Higher capacity per cell

Installing more TRXs - Disadvantages More antennas on roof top (Air combining) Additional losses if WBC has to be used Less (indoor) coverage

More frequencies per site needed Tighter reuse necessary decreasing quality

1 · 1 · 335



Trunking efficiency 1TRX

2.7 Erl.

+2.7 Erl

2TRX

8.2 Erl

+5.3 Erl (+1 Signalling TS)

3TRX

14.9 Erl

+6.7 Erl

4TRX

21.0 Erl


5TRX

28.3 Erl

+7.3 Erl

6TRX

34.7 Erl


7TRX

42.1 Erl

+7.4 Erl

….



3.2.4 Network Evolution - Capacity Approach (4) Implementing additional sites - Advantages Reuse can remain the same (smaller cell sizes) Needs less frequency spectrum higher spectrum efficiency

Implementing additional sites - Disadvantages Additional site cost (rent) Re-design of old cells necessary (often not done)

1 · 1 · 336





3.3 Cell Structures

1 · 1 · 337




3.3 Cell Structures

3.3.1 Cell Structures and Quality Frequency re-use in cellular radio networks allow efficient usage of the frequency spectrum but causes interference

Interdependence of Cell size Cluster size Re-use distance Interference level Network Quality

interferer region

1 · 1 · 338




3.3 Cell Structures

3.3.2 Cell Re-use Cluster (Omni Sites) (1)

2 7

1 6

R

1 · 1 · 339

D

3 2

4 5

7

3 1

6

4 5




3.3 Cell Structures

3.3.2 Cell Re-use Cluster (Omni Sites)(2)

1 4

2 5

D

6 8

7 10

3

11

1 · 1 · 340

9 12




3.3 Cell Structures

3.3.4 Cell Re-use Cluster (Sector Site) (1)

1 · 1 · 341




3.3 Cell Structures

3.3.5 4x3 Cell Re-use Cluster (Sector Site) (2)

1 · 1 · 342




3.3 Cell Structures

3.3.6 Irregular (Real) Cell Shapes

5

1

2

1 · 1 · 343

4

5

6

Network Border

3

Coverage Hole




7

Island


3.4 Frequency Reuse

1 · 1 · 344




3.4 Frequency Reuse

3.4.1 GSM Frequency Spectrum GSM 900 DL: 935-960 MHz UL: 890-915 MHz 200 kHz channel spacing 124 channels ARFCN 1 - 124

E-GSM DL: 925-935 MHz UL: 880-890 MHz 200 kHz channel spacing Additional 50 channels ARFCN 0, 975 - 1023 200 kHz channel spacing 124 channels

GSM 850 DL: 869-894 MHz ARFCN: 128 - 251

UL: 824-849 MHz

GSM 1800 DL: 1805-1880 MHz UL: 1710-1785 MHz 200 kHz channel spacing 374 channels ARFCN 512 - 885

1 · 1 · 345




3.4 Frequency Reuse

3.4.2 Impact of limited Frequency Spectrum Bandwidth is an expensive resource Best usage necessary Efficient planning necessary to contain good QoS when the traffic in the network is increasing smaller reuse Multiple reuse pattern (MRP) usage implementation of concentric cells / microcells/dual band implementation of Frequency Hopping Baseband Synthezised

1 · 1 · 346




3.4 Frequency Reuse

3.4.3 What is frequency reuse? As the GSM spectrum is limited, frequencies have to be reused to provide enough capacity The more often a frequency is reused within a certain amount of cells, the smaller the frequency reuse Aim: Minimizing the frequency reuse for providing more capacity REUSE CLUSTER: Area including cells which do not reuse the same frequency (or frequency group)

1 · 1 · 347




3.4 Frequency Reuse

3.4.4 RCS and ARCS (1) Reuse Cluster Size - RCS If all cells within the reuse cluster have the same amount of TRXs, the reuse per TRX layer can be calculated:

RCS =

B # TRX / cell

Average Reuse Cluster Size - ARCS If the cells are different equiped, the average number of TRXs has to be used for calculating the average reuse cluster size:

ARCS =

1 · 1 · 348

B # TRX / cell




3.4 Frequency Reuse

3.4.5 RCS and ARCS (2) The ARCS is giving the average reuse of the network when using the whole bandwidth and all TRXs per cell E.g: if we want to have the reuse of all non hopping TCH TRXs, we have to use the dedicated bandwidth and the average number of non hopping TCH TRXs per cell to get the ARCS of this layer type. Each cell has only one BCCH. Therefore the BCCH reuse is an RCS and not an ARCS!

1 · 1 · 349




3.4 Frequency Reuse

3.4.6 Reuse Cluster Size (1) Sectorized sites 4 sites per reuse cluster 3 cells per site REUSE Cluster Size: 4X3 =12

1

2

4

3 1

2

4

3 8

8 9

6 7

10

9

1 · 1 · 350

6 7

5




12

5

11

10 12

11

3.4 Frequency Reuse

3.4.7 Reuse Cluster Size (2) Sectorized sites 3 sites per reuse cluster 3 cells per site REUSE Cluster Size 3X3 = 9 1

2

4

3

5 6

7

8 9

1

2

4

3

6 7

8 9

1 · 1 · 351




5

3.4 Frequency Reuse

3.4.8 Reuse Distance

cell A

reus ed ist an ce

D = f ⋅ R ⋅ 3 ⋅ RCS ⎧⎪ 1 f = ⎨2 ⎪⎩ 3

omnidirectional cells three - sectorized cells interferer region

1 · 1 · 352

cell B



In theory reuse distance and reuse shouldn’t be dependent. In reality, when the cells are not well designed: bigger cell overlapp =>higher frequency reuse, smaller reuse distance


3.4 Frequency Reuse

3.4.9 Frequency Reuse Distance D = distance between cell sites with the same frequencies R = service radius of a cell B = number of frequencies in total bandwidth RCS = reuse cluster size, i.e. one cell uses B/RCS frequencies In hexagonal cell geometry: D/R = f · omni cells:

3 RCS

Examples (omni): RCS = 7: D/R = 4.6 RCS = 9: D/R = 5.2 RCS =12: D/R = 6.0

f=1; sector cells: f=2/3

Received Power Frec, A

Frec

Frec, B

C/I

site A 0

1 · 1 · 353

σ

R

distance




site B D

3.4 Frequency Reuse

3.4.10 Frequency Reuse: Example

BCCH RCS

No sectorization 7 cells per cluster BCCH RCS = 7

TCH Reuse: Depending on BW and Number of installed TRXs per cell Example: B= 26 4TRXs per cell

TCH RCS =

1 · 1 · 354

interferer region

TCH RCS

26 − 7BCCH −1Guard =6 3 All Rights Reserved © Alcatel-Lucent 2010


BCCH reuse is always RCS, because we don’t need to use an average (always one BCCH per cell). Omni cells To calculate the TCH reuse in the example, the BCCH RCS is subtracted from the bandwidth B and the average number of TCH TRX per cell is 4 minus 1 BCCH = 3



3.5 Cell Planning

1 · 1 · 355




3.5 Cell Planning

3.5.1 Cell Planning - Frequency Planning (1) Can frequency planning be seen independently from cell planning?

Discussion

1 · 1 · 356




3.5 Cell Planning

3.5.2 Cell Planning - Frequency Planning (2) Bad cell planning Island coverage Big overlap areas

disturbing the reuse pattern bigger reuse necessary

Good cell planning Sharp cell borders Small overlap areas

1 · 1 · 357

good containment of frequency tighter reuse possible




3.5 Cell Planning

3.5.3 Influencing Factors on Frequency Reuse Distance Topography Hilly terrain Usage of natural obstacles to define sharp cell borders tighter frequency reuse possible Flat terrain design

Achieveable reuse much more dependent on the accurate cell

Morphology Water

low attenuation

City

high attenuation

1 · 1 · 358

high reuse distance low reuse distance




3.5 Cell Planning

3.5.4 Conclusion In cellular mobile networks, the frequency reuse pattern has a direct influence on the interference and hence the network quality Regular hexagonal patterns allow the deduction of engineering formulas In real networks, cell sizes and shapes are irregular due to Variation in traffic density Topography Land usage

Engineering formulas allow the assessment of the network quality and worstcase considerations, but the real situation must be proved!

1 · 1 · 359




3.5 Cell Planning

3.5.5 Examples for different frequency reuses Big city in the south of Africa: BCCH reuse 26 Irregular cell design Mixed morphology Lots of water Flat terrain plus some high sites

Big city in eastern Europe BCCH reuse 12 Regular cell design Flat area Only urban environment

1 · 1 · 360





3.6 Interference Probability

1 · 1 · 361





3.6.1 Interference Theory (1) C/I restrictions 9dB for co-channel interference -9 dB for adjacent channel interference

P rec

Received Power Prec, A

Prec, B

C/ I

0

1 · 1 · 362

σ

dista nce

R

D



C/I is the difference between the two received power lines when shifting the two transmitters towards each other, the area where the C/I is > 9dB shrinks At a certain distance of the two transmitters, the C/I can never fulfil the GSM criteria -> minimum site distance. It has to be kept in mind, that of course other cells will be inbetween two cells transmitting at the same frequency!



3.6.2 Interference Theory (2)

ARCS 6.5..9.0 7.0..9.5 8.5..11.0 12.0..16.0

Interference probability C/Imed is the calculated carrier to interference ratio at a certain location (pixel)

Pint[%] 10 7.5 5.0 2.5

Interferer probability [%]

Probability density function [%]

100% 3.6 Interference Probability

5,0% 4,0%

80%

3,0%

60%

2,0%

40% Margin

1,0%

20%

0,0% C/Ithr

C/Imed

C/I [dB] →

0% -20

-15

-10

-5

0

5

10

15

20

C/I - C/Ithr[dB] 1 · 1 · 363



The marked area left of C/Ithr is the area of interference. Although the received level is above the threshold, there is a certain probability to get interference because of the standard deviation of the received signal.



3.6.3 DF - Cumulative Probability Density Function

Pint = P ( C/I < C/I thr) P int 1 0,9 0,8 0,7 0,6 0,5 0,4 0,3 0,2 0,1 0

DF - Cumulative Probability Density Function

D

R

1 · 1 · 364




Distance from serving cell


3.6.4 Interference Probability dependent on Average Reuse

ARCS = Pint [%]

# of frequencies in used bandwidth average # of carriers per cell Examples: Pint[%] ARCS 10 6.5...9 7.5 7...9.5 5 8.5...11 2.5 12...16

12 9 6 3 0

5

1 · 1 · 365

10

15

20




25

ARCS


3.7 Carrier Types

1 · 1 · 366




3.7 Carrier Types

3.7.1 Carrier Types - BCCH carrier BCCH frequency is on air all the time If there is no traffic/signaling on TS 1 to 7 dummy bursts are transmitted PC (Power Control) and DTX (Discontinuous Transmission) are not allowed Important for measurements of the mobile

1 · 1 · 367



The BCCH frequency must be transmitted with full power all the time! Otherwise the measurements of the neighborcell levels would be useless.


3.7 Carrier Types

3.7.2 Carrier Types - TCH carrier PC allowed and recommended for UL and DL Reduction of transmit power according to the actual path loss Careful parameter tuning for DL necessary

DTX allowed and recommended for UL and DL Discontinuous Transmission If there is no speech, nothing is transmitted Generation of comfort noise at receiving mobile

TCH not in use

no signal is transmitted

Special case: Concentric cells Different re-uses for inner and outer zone are possible

1 · 1 · 368



PC and DTX are reducing the overall interference in the network. As a TCH is not transmitting anything when not in use, the interference level is strongly related to the traffic on the interfereing cells.



3.8 Multiple Reuse Pattern MRP

1 · 1 · 369




3.8 Multiple reuse pattern

3.8.1 Meaning of multiple reuse pattern (1) For different types of carriers, different interference potential is expected As the BCCH carrier has the highest interferer potential because of being on air all the time and the BCCH channel itself is accepting only low interference, the REUSE on the BCCH layer is higher then on other layers TCH layers can be planned with a smaller REUSE Inner zones of concentric cells are able to deal with the smallest reuse in non hopping networks

1 · 1 · 370





3.8.2 Meaning of multiple reuse pattern (2)

REUSE clusters for INNER ZONE layer TCH layer

BCCH layer

1 · 1 · 371



When applying different reuses in the different cell layers, of course separated bands are necessary!



3.8.3 GSM restrictions Intra site minimum channel spacing 2 Intra cell minimum channel spacing 2 (ETSI recommends 3, but with Alcatel EVOLIUM capabilities this value can be set to 2) constrains:

fC

, ,1 f C2

,...

f C3

fA1,fA2,fA3,...

Uplink power control enabled Intra cell interference handover enabled

fB

Frequencies fAx,fBx,fCx,… must have at least 2 channels spacing Frequencies fx1,fx2,fx3,… must have at least 3 channels spacing

1 ,f B2 ,

1 · 1 · 372

fB

3 ,.

.. All Rights Reserved © Alcatel-Lucent 2010


The Intra cell minimum channel spacing of 3 is given by the combiner in the BTS, to avaoid IM problems Important remark: the whole training is compliant to the co-cell constraint of 3 channels ; this is more restrictive than the BTS capability of filtering the channels on frequency n*200 kHz Acc to A.Krause: for Evolium BTS standard equipped with WBC the co-cell constraint can be only 2 channels. (A channel spacing of 2 was tested @Vodacom in 1999 but the result was not better than with channel spacing of 3.)



3.9 Intermodulation

1 · 1 · 373




3.9 Intermodulation

3.9.1 Intermodulation problems (1) IM Products GSM900 In a GSM 900 system intermodulation products of 3rd and 5th order can cause interference 2 * f1,t – f2,t = f2,r / 2 * f2,t – f1,t = f1,r 3 * f1,t – 2 * f2,t = f2,r / 3 * f2,t – 2 * f1,t = f1,r

Frequency planning must avoid fulfilling these equations Both frequencies must be on the same duplexer To avoid intra band IM inside GSM900 the following frequency separations shall be avoided: 75/112/113 channels

IM5

IM3

1 · 1 · 374



Info from techn. dept: If a WBC has to be used because of the number of TRXs, the output power is not high enough to cause problems. -> No intermodulation problems .


3.9 Intermodulation

3.9.2 Intermodulation problems (2) IM Products GSM1800 In a GSM 1800 system, only intermodulation products of 3rd order can cause measurable interference 2 * f1,t – f2,t = f2,r / 2 * f2,t – f1,t = f1,r Frequency separations to be avoided 237/238 channels

IM Products Dual Band (GSM900/GSM1800) f1800,t – f900,t = f900,r Decoupling between the GSM 1800 TX path and the GSM 900 RX path is less than 30 dB (e.g. same antenna used!)

1 · 1 · 375




3.9 Intermodulation

3.9.3 Intermodulation problems (3) - Summary INSIDE Problem: IM3 / IM5 carrier/antenna G3 900 1 G3 900 2 ore more G3 1800 1 G3 1800 2 or more carrier/antenna G2 900 w/o dupl 1 2 or more G2 900 with dupl 1 2 or more G2 1800 w/o dupl 1 2 or more G2 1800 with dupl 1 2 2

OUTSIDE Problem: Dual Band Colocated BTSs G3 900 G2/G3 1800 G2 900 w/o dupl

G2/G3 1800

G2 900 with dupl

G2/G3 1800

1 · 1 · 376

Problem can be solved by hopping over more than 10 frequencies

restriction no 112/113 (IM3) and 75 (IM5) no 237/238 (IM3) no IM5 quality degradation measurable no no no 112/113 (IM3) and 75 (IM5) no no no dud2(high Power) -> no dupd -> 237/238

Problem only for non hopping and BCCH carriers f(1800,t) - f(900,t) = f(900,r) no f(1800,t) - f(900,t) = f(900,r)



Caution: SFH doesn’t bring additional benefits when hopping over more than 4 frequencies


3.9 Intermodulation

3.9.4 Treating “neighbor” cells Cells, which are not declared as neighbor cells but are located in the neighborhood may use adjacent frequencies if it is not avoidable, but no co channel frequencies Cells which are declared as neighbors, thus have HO relationships, must not use co or adjacent frequencies If an adjacent frequency is used, the HO will be risky and at least audible by the

1 · 1 · 377




3.9 Intermodulation

3.9.5 Where can I find neighbor cells? At the OMC-R for each cell a list of neighbor cells is defined Maximum number of neighbors: 32 The list of neighbors and their frequencies is transmitted to the mobile to be able to perform measurements on these frequencies In case of a HO cause, the HO will be performed towards the best neighbor

1 · 1 · 378





3.10 Manual frequency planning

1 · 1 · 379




3.10 Manual Frequency Planning

3.10.1 Frequency planning (1) No fixed method Free frequency assignment possible, but very time consuming for larger networks For easy and fast frequency planning: use group assignment Example: 18 channels, 2TRX per cell

1 · 1 · 380

ARCS 9





3.10.2 Frequency planning (2)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 A1 B1 A2 B2 A3 B3 A4 B4 A5

GSM restrictions are automatically fulfilled, if on one site only groups A* or only B* are used

1 · 1 · 381





3.10.3 Exercise: Manual frequency planning (1)

1 · 1 · 382



A1 A2

A2 A3

B4

B1 A4 B2

B1 B3

B2

A1 A2

A5

A3 A4

B2

A5

B4

A1 A2

A2


A3

B1


3.10.4 Exercise: Manual frequency planning (2)

A1 A2

A2 A3

B2

B1 B1

B3

B2

B2

A5 A1

A4

1 · 1 · 383

A5

B4

A3 A2

A4

B4

A1 A2

A3




A2

B1


3.10.5 Discussion: Subdivide frequency band?

Any subdivision of the frequency band is reducing the spectrum efficiency! Separations should be avoided if possible! As the BCCH has to be very clean, it is nevertheless recommended to use a separated band and select a bigger reuse

1 · 1 · 384



The focus in the discussion is not the fx band splitting by fx management authorities.



3.10.6 Hint for creating a future proofed frequency plan If a frequency plan is implemented, using all available frequencies in the most efficient way, it is very difficult to implement new sites in the future! New sites would make a complete re-planning of the surrounding area or the whole frequency plan necessary To avoid replanning every time when introducing new sites, it is recommended to keep some Joker frequencies free These Joker frequencies can be used for new sites (especially BCCH TRXs) unless it is impossible to implement new sites without changing a big part of the frequency plan New frequency plan necessary!

1 · 1 · 385





3.10.7 Implementing a frequency plan

If only a few frequencies have to be changed, the changes can be done at the OMC-R Disadvantage: Every cell has to be modified separately Downtime of the cell approx. 5 minutes

If lots of changes have to be done, it is of advantage to use external tools Since B6.2 the complete frequency plan can be ed from the OMC the ed file can be modified by the tool (A9155 PRC Generator) the the new plan is ed into the network and activated at once

1 · 1 · 386





3.11 BSCI planning

1 · 1 · 387




3.11 BSIC Planning

3.11.1 BSCI allocation Together with the frequencies the Base Transceiver Station Identity Code (BSIC) has to be planned The BSIC is to distinguish between cells using the same BCCH frequency BSIC = NCC (3bits) + BCC (3bits) NCC Network (PLMN) Colour Code

BCC - Base Transceiver Station (BTS) Colour Code

BSIC planning is ed by the A9155 (Alcatel Radio Network Planning Tool)

1 · 1 · 388




3.11 BSIC Planning

3.11.2 BSIC planning rules The same combination BCCH/BSIC must not be used on cell influencing on each other (having a mutual interference <>0) BSIC allocation rules: Avoid using same BCCH/BSIC combination of: neighbor cells second order neighbor cells (the neighbors of neighbor cell (OMC limitation))

C

B

neighbor Cell BCCH:24 neighbor Cell

A

BSIC: must NOT be 36

BCCH:24 BSIC:36

Serving Cell BCCH:10 BSIC: any

1 · 1 · 389




3.11 BSIC Planning

3.11.3 Spurious RACH Bad BSIC planning can cause SDCCH congestion cause by the spurious RACH problem, also known as “Ghost RACH” This problem occurs, when a mobile sends an HO access burst to a TRX of cell A using the same frequency as a nearby cell B uses on the BCCH Both cells using the same BSIC and Training Sequence Code TSQC, the HO access burst is understood by the cell B as a RACH for call setup Therefore on cell B SDCCHs are allocated everytime a HO access burst is sent from the mobile to the cell A

1 · 1 · 390



If in cell B the BCCH and TRX 2 exchange their frequencies (BCCH gets the fx of TRX2 and TRX2 gets the fx of BCCH): no problem with spurious RACH

Cell B F1 F2 BSIC=1

Cell C


Cell A F5 F1 BSIC=1

3.11 BSIC Planning

3.11.4 Summary For optimal usage of your frequency spectrum a good cell design is essential Use larger reuse for BCCH frequencies Use spectrum splitting only when necessary

1 · 1 · 391





3.12 Capacity Enhancement Techniques

1 · 1 · 392





3.12.1 Capacity enhancement by planning Interference reduction of cells Check of antenna type, direction and down tilt This is a check of cell size, border and orientation

Check of proper cabling Is TX and RX path on the same sector antenna?

Check of the frequency plan Introduction of a better frequency plan

1 · 1 · 393





3.12.2 Capacity enhancement by adding feature Frequency hopping Base band hopping Synthesized frequency hopping

Concentric cells Half rate

1 · 1 · 394





3.12.3 Capacity enhancement by adding TRX Adding TRX to existing cells Multi band cells Concentric cells

1 · 1 · 395





3.12.4 Capacity enhancement by adding cells Adding of cells at existing site locations Adding new cell = adding new BCCH Dual band Adding cells using another frequency band

Cell splitting Reduction of cell size Change of one omni cell into several cells/sector cells

1 · 1 · 396





3.12.5 Capacity enhancement by adding sites Dual band/multi band network Adding of new sites in new frequency band

Multi layer network Adding of new sites in another layer E.g. adding micro cells for outdoor coverage

Indoor coverage Adding micro cells indoor coverage Adding macro cells indoor coverage

1 · 1 · 397




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1 · 1 · 398 Basics · Basics RNE · RNE (Radio Network Engineering) B11 Fundamentals


This page is left blank intentionally


4 Radio Interface 4.1 GSM Air Interface

1 · 1 · 399




4.1 GSM Air Interface

4.1.1 Radio Resources

Radio Spectrum Allocation

Frequency (FDMA)

Time (TDMA)

Carrier Frequencies (ARFCN) Cell Allocation (CA)

Timeslot 0 <7

Mobile Allocation (MA)

1 · 1 · 400

FDMA TDMA ARFCN TN FN

TDMA Frames 0




4.1.2 GSM Transmission Principles (1) FDMA and TDMA with 8 time slots per carrier RF frequency band (880) 890 ... 915 MHz Uplink (MS → BS) (925) 935 ... 960 MHz Downlink (BS → MS) 1710 ... 1785 MHz Uplink 1805 ... 1880 MHz Downlink

(E)GSM: GSM1800:

200 kHz bandwidth Number of carriers: GSM: Flower E-GSM: Flower Flower DCS : Flower

(n) (n) (n) (n)

124 (GSM); 374 (DCS); 49 (E-GSM)

= 890 + 0.2 · n = 890 + 0.2 · n = 890 + 0.2 · (n -1024) = 1710.2 + 0.2 · (n - 512)

MHz MHz MHz MHz

with with with with

(E)GSM: Fupper (n) = Flower (n) + 45 MHz DCS: Fupper (n) = Flower (n) + 95 MHz

1 · 1 · 401




1 ≤ n ≤ 124 0 ≤ n ≤ 124 975 ≤ n ≤ 1023 512 ≤ n ≤ 885


4.1.3 GSM Transmission Principles (2) Channel types Traffic Channels (TCH) Full rate Half rate

Control Channels (CCH) Broadcast Control Channel (BCCH) Common Control Channel (CCCH) Dedicated Control Channel (DCCH)

TDMA frame cycles 26 cycle for traffic channels 51 cycle for control channels

1 · 1 · 402





4.1.4 Advantages of Signal Processing

Bad propagation conditions

Spectrum limitations Operator

P t Good spectrum efficiency

1 · 1 · 403

Good transmission quality





4.1.5 Signal Processing Chain

stealing bit and FACCH speech input speech coding

error protection

interleaving

encryption

Loss Noise Interference Fading speech output speech decoding

error correction

de-interleaving

decryption

stealing bit and FACCH

1 · 1 · 404




modulation

radio channel

demodulation

4 Radio Interface

4.2 Channel Coding

1 · 1 · 405




4.2 Channel Coding

4.2.1 Speech Coding

Coding algorithm: RPE-LTP

20 ms of coded speech

Pre-computation RPE = Regular Pulse Excitation Model of human voice generation

260 bits speech block

LTP = Long Term Prediction Reduction of bit rate

Bit rate: 13 kBit/s 182 class 1 bits

78 class 2 bits

sensitive to bit errors must be protected

robust to bit errors

Coding at fixed network: PCM A-law Bit rate: 64 kBit/s

1 · 1 · 406




4.2 Channel Coding

4.2.2 Error Protection Speech (full rate)

Messages (signalling data)

260 bits Class 1a

184 bits

Fire Code 184

Class 1b

50 bits

Cyclic code

Parity check

4 0

Convolutional Code r = 1/2, K = 5

4

Tail bits

5 0

78 bits

Tail bits

3

132

4

Convolutional Code r = 1/2, K = 5

456 = 24 x 19

37 8 456 bits in 20 ms = 22.6 kbit/s

1 · 1 · 407

Class 2

132 bits




78

= 456 = 8 x 57

4.2 Channel Coding

4.2.3 Interleaving and TDMA Frame Mapping

57 bits Block n (456 bits) Block n-1 (456 bits) 0123 4 5 6 7 0123 4 5 6 7

Block n+1 (456 bits) 0123 4 5 6 7 Interleaving

2 x 57 bits

.... 114 bits 114 bits 114 bits 114 bits 114 bits 114 bits 114 bits 114 bits .

.... . Addition of stealing flags

.... 116 bits 116 bits 116 bits 116 bits 116 bits 116 bits 116 bits 116 bits .

.... . Mapping onto bursts

.... .

burst n-3

burst n-2 burst n-1

burst n

burst n+1 burst n+2 burst n+3 burst n+4

1 time slot

1 · 1 · 408




.... .

4.2 Channel Coding

4.2.4 Encryption

Network Algorithm A3

AuC IMSI Ki

Ki

Random number generator

Mobile station

Authenticatio n yes/no +

Algorithm A3

SRES (32 bit)

RAND (128 bit)

Ki RAND

RAND

Algorithm A8

Algorithm A8 Kc

Kc (64 bit)

Algorithm A5 original data

+

1 · 1 · 409

Algorithm A5 encrypte d data

encrypte d data




+

original data

SIM Card

4.2 Channel Coding

4.2.5 Burst Structure A burst contains one data "portion" of one timeslot TDMA frame: time between two bursts with same timeslot number The burst also consists of:

Normal Burst

Guard period (GP): allows for transition and settling times Tail bits: allow for small shifts in time delay (synchronisation) Stealing flags: to indicate FACCH (control channel) data Training sequence: for equalization purposes

TDMA frame = 4.615 ms

0

1

2

Data GP 3

57 bits

tail bits

3

4

5

Training Sequence 1

26 bits

6

1

stealing flags




0

Data

156.25 bit periods = 0.577 ms

1 · 1 · 410

7

57 bits

3 GP tail bits

4.2 Channel Coding

4.2.4 Synchronisation

1

transmitted from BTS 0 1 2 3 4 5 6 7 0 1 (downlink)

0 1 2 3 1 2

4

0 1 2

2

TT

TT

1 2

3 RACH

non-synchronized

3 TS delay

received at BTS (uplink) received at MS (downlink) transmitted from MS (uplink)

0 1 2 3 4 5 6 7 0 1

0 1 2 3 4 5 6 7 0 1 TT

0 1 2 3 4 5 6 7 0 1 TT

synchronized

MS delay line setting

Transmitted bursts need a travelling time (TT) to the receiver For network access, the MS sends a (non-synchronized) shortened RACH burst The BSS measures the TT and generates a timing advance value TA which is transmitted to the MS

1 · 1 · 411




4.2 Channel Coding

4.2.5 Modulation Gaussian minimum shift keying Based on phase shift keying Reduction of required bandwidth Maximum phase change during one bit duration Baseband filtering to achieve continuous phase changes

cos Data

∫

ϕ

x

≈

+ 90°

sin

1 · 1 · 412

x




to RF modulator

4.2 Channel Coding

4.2.6 Propagation Environment Radio propagation is characterised by dispersive multipath caused by reflection and scattering Moving MS causes Doppler spectrum → Definition of propagation models in the time domain to allow channel simulations TUxx (Typical Urban) RAxx (Rural Area) HTxx (Hilly Terrain) xx = speed in km/h

see also GSM 05.05, 11.20, 11.21 1 · 1 · 413




4.2 Channel Coding

4.2.7 Equalizing Purpose: equalize distortions in transmission spectrum Adaptive filtering required 0.1

Filter parameters determined out of the training sequence Filter parameters change from burst to burst

BER

Equalizer takes advantage from multipath propagation (path diversity) 0.01

Equalizer none Alcatel MLSE 0.001 0

1

2

3

4

5

Delay of second path [chips]

1 · 1 · 414




6

7

8

4.2 Channel Coding

4.2.8 Definition of Bit Error Rates FER = Frame Erasure Rate Ratio of corrupted frames, indicated by a wrong CRC (cyclic redundancy checksum) and BFI (bad frame indicator)

RBER = Residual Bit Error Rate considering corrupted frames not recognized as bad frames

BER = total bit error rate Consideration of class 1 or 2 bits → e.g. RBER1b, RBER2

see also GSM 05.05, 11.20, 11.21 1 · 1 · 415




4.2 Channel Coding

4.2.9 Speech Quality

BER >0.01 <0.005 <0.0025 <0.0003 <0.0001

Thresholds:

Quality no communication “bad” “marginal” “good” “excellent”

1 · 1 · 416

C/I: Ec/No: BTS (GSM900): HH (GSM900): BTS (GSM1800): HH (GSM1800):



HH - handheld

RXQUAL_0

BER <0,2%

RXQUAL_1

0,2% <0,4%

RXQUAL_2

0,4% <0,8%

RXQUAL_3

0,8% <1,6%

RXQUAL_4

1,6% <3,2%

RXQUAL_5

3,2% <6,4%

RXQUAL_6

6,4% <12,8%

RXQUAL_7

12,8%


9 dB 8 dB -104 dBm -102 dBm -104 dBm -100 dBm

4.2 Channel Coding

4.2.10 Dependence of BER on Noise and Interference

BER1 for marginal speech quality: 0.25% required C/I ≈ 9 dB for TU50 environment but: signal must not be close to noise floor!

BER1 →

Variation of BER1 over C/I Parameter: Ec/N0 How to find a quality figure?

TU50

C/I [dB] →

1 · 1 · 417




4.2 Channel Coding

4.2.13 Frequency Hopping (1) 0 Lognormal fading Raleygh fading

-10

-20

Received Power [dBm]

Problem: specific fading pattern for each used frequency Fast MS cope with the situation (due to signal processing) Slow MS suffer from fading holes Solution: change the fading pattern by frequency hopping

-30

-40

-50

-60

Fading holes

1 · 1 · 418

Distance [m]




49.9

47.3

44.7

42.1

39.4

36.8

34.2

31.6

29.0

26.3

23.7

21.1

18.5

15.9

13.2

10.6

8.0

5.4

2.8

0.1

-70

4.2 Channel Coding

Variation of BER1 over Ec/N0 TU environment, flat fading, v = 0 km/h (worst case) Parameter: number of hopping frequencies

BER →

4.2.14 Frequency Hopping (2)

Compensation with 4 hopping frequencies possible

Ec/N0 [dB] →

1 · 1 · 419




4.2 Channel Coding

4.2.15 The OSI Reference Model

Application layer 7 Presentation layer 6 Session layer

5

Transport layer 4 Network layer 3

04.07/08 08.58/4.0 8 04.05/06 08.56

Data link layer 2 Physical layer 1

04.04 08.54

End system

Transportation system

End system

Definition in GSM recommendations: layers 1 to 3 Notion of "Physical" channels and "Logical" channels

1 · 1 · 420




4.2 Channel Coding

4.2.16 GSM Burst Types (1) Normal Burst

For regular transmission

Frequency Correction Burst

Contains 142 zeros (0) → pure sine wave Allows synchronisation of the mobile's local oscillator

Synchronisation Burst

Consists of an enlarged unique training sequence code (TSC) Contains the actual FN → time synchronisation

Access Burst

Shortened burst (unique TSC and enlarged guard period) Timeslot overlapping avoided at BTS when MS accesses network

Dummy Burst

"Filler" for unused BCCH timeslots → BCCH permanently on air Similar to normal burst (defined mixed bits for data, no stealing flag)

1 · 1 · 421




4.2 Channel Coding

4.2.17 GSM Burst Types (2) Normal burst TB 3

57 data bits

1

26 bit training 1 sequence

57 data bits

TB GP 3 8.25

Frequency correction burst TB 3

TB GP 3 8.25

142 fixed bits (pure sine wave)

Synchronisation burst TB 3

64 bit training sequence

39 data bits

39 data bits

Access burst TB 41 bit synchronisation 8 sequence

1 · 1 · 422

36 data bits

TB 3




enlarged GP 68.25 bit

TB GP 3 8.25

4.2 Channel Coding

4.2.18 Logical Channels

Traffic channel

Control channel

Speech

Data

Broadcast channel

CCCH

TCH/FS

TCH/F9.6

FCCH

RACH

FACCH

SDCCH

TCH/HS

TCH/F4.8

SCH

PCH

SACCH

CBCH

TCH/F2.4

BCCH

AGCH

TCH/H4.8 TCH/H2.4

1 · 1 · 423




Associated Dedicated channel channel

4.2 Channel Coding

4.2.19 Possible Channel Combinations

1

TCH/F+FACCH/F+SACCH/TF

2

TCH/H(0.1)+FACCH/H(0.1)+SACCH/TH(0.1)

3

TCH/H(0.0)+FACCH/H(0.1)+SACCH/TH(0.1)+TCH/H(1.1)

4

FCCH+SCH+BCCH+CCCH

5

FCCH+SCH+BCCH+CCCH+SDCCH/4(0..3)+SACCH/C4(0..3)

6

BCCH+CCCH

7

SDCCH/8(0..7)+SACCH/C8(0..7)

CCCH = PCH+RACH+AGCH Combination 4 and 5 is only possible on TS0 of the first (BCCH) carrier Combination 6 is possible on TS2, TS4, or TS6 of the BCCH carrier

1 · 1 · 424




4.2 Channel Coding

4.2.20 Channel Mapping (1)

.......

0 12 3 4 5 6 70 12 3 4 5 6 7 0 12 3 4 5 6 7 0 12 3 4

....... time

.......

one TDMA frame = 4.616 ms

Presentation of consecutive TDMA frames on the vertical axis

1 · 1 · 425

Information packages are always related to the same timeslot number! Bursts are transmitted and received every TDMA frame duration (4.616 ms)




4.2 Channel Coding

4.2.21 Channel Mapping (2) not combined BCCH 0

combined BCCH

downlink

uplink

FCCH

RACH

FCCH

downlink FCCH

SCH

RACH

SCH

SCH

BCCH

BCCH

TCH

uplink

SDCCH3

SDCCH3

RACH

RACH

RACH

TCH

RACH

RACH

TCH

SACCH0

SACCH2

RACH

FCCH

FCCH

RACH

SCH

SCH

TCH SACCH3

RACH

RACH

RACH

TCH

RACH

RACH

RACH

TCH

RACH

RACH

RACH

TCH

RACH

RACH

TCH

RACH

RACH

TCH

RACH

CCCH

CCCH

RACH

RACH

RACH

TCH

FCCH

RACH

FCCH

FCCH

RACH

RACH

TCH

SCH

RACH

RACH

SCH

SCH

RACH

RACH

TCH

RACH

RACH

TCH

RACH RACH

RACH

RACH

RACH

RACH

RACH

RACH

RACH

RACH

25

RACH

RACH

RACH

0

RACH

RACH

TCH

RACH

SDCCH0

SDCCH1 RACH

TCH

RACH

RACH

TCH

FCCH

FCCH

RACH

RACH

TCH

SCH

RACH

SCH

SCH

RACH

RACH

TCH

RACH SDCCH2

SDCCH2

RACH

RACH

TCH

RACH

RACH

TCH

RACH

RACH

RACH

TCH

RACH

RACH

RACH

TCH

RACH

RACH

RACH

RACH

SDCCH0

SDCCH0

RACH SDCCH3

RACH

FCCH

FCCH

TCH

SCH

RACH

SCH

SCH

TCH

RACH

SDCCH3

SDCCH0

SDCCH0

SDCCH4

SDCCH4

SDCCH1

SDCCH1

SDCCH5

SDCCH5

SDCCH2

SDCCH2

SDCCH6

SDCCH6

30

SDCCH3

SDCCH3

SDCCH7

SDCCH7

SDCCH4

SDCCH4

SACCH0

SACCH4

SDCCH5

SDCCH5

SACCH1

SACCH5

SDCCH6

SDCCH6

SACCH2

SACCH6

SDCCH7

SDCCH7

SACCH3

SACCH7

SACCH0

SACCH4

40

TCH SDCCH1

SDCCH1

RACH

TCH SACCH0

SACCH2

RACH

TCH

RACH

RACH

RACH

TCH

RACH

RACH

RACH

TCH

RACH

TCH SACCH1

SACCH3

RACH

TCH SDCCH2

SDCCH2

RACH

TCH

RACH

TCH

25

1 · 1 · 426

SDCCH3

TCH

FCCH

CCCH

SACCH3

TCH

RACH

50

SACCH7

20

TCH 12 SACCH

SDCCH3

RACH

CCCH

SDCCH2

TCH

SDCCH1 RACH

40

SDCCH2

TCH

RACH

RACH

CCCH

SACCH2

TCH

FCCH

CCCH

SACCH6

SDCCH0

RACH CCCH

10

CCCH

RACH

30

SDCCH1

TCH CCCH

CCCH

SDCCH1

TCH 12 SACCH

SACCH1 RACH

20

SACCH1

TCH

RACH

SCH

CCCH

SACCH5

TCH

RACH

Traffic channels Follows a 26-cycle Duration: 120 msec

CCCH

FCCH

CCCH

SDCCH0

TCH CCCH

RACH

10

SDCCH0

TCH

RACH

Follows a 51-cycle Duration: 235.4 msec Consists mostly of four consecutive blocks Synchronisation with FCCH and SCH

uplink

TCH

RACH

CCCH

downlink 0

TCH

RACH

Control channels

TCH TCH

RACH BCCH

SDCCH

up/ downlink 0




50

4.2 Channel Coding

4.2.22 TDMA Frame Structure for TCHs

Hyperframe

2048 superframes of 6.12 s duration

Superframe

51 multiframes of 120 ms duration

Multiframe Frame Time slot

3 h 28 m 53 s 6.12 s

0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

0

TB 3

1 · 1 · 427

1

2

57 data bits

3

1

4

26 bit training 1 sequence

5

57 data bits




6

7

TB 3

GP 8.2 5

120 ms 4.615 ms 0.577 ms

Abbreviations and Acronyms

AMR AMSS AN ARCS ARFCN AS AS ASMA ASMB AuC BC BCU BCLA BCR BCU BCCH BCF BG

Advanced Multi Rate (TC) Aeronautical Mobile Satellite Services Antenna Network (BTS) Average Reuse Cluster Size Absolute Radio Frequency Channel Access Switch (BSC) Alarm Surveillance (O&M) A-ter Submultiplexer A A-ter Submultiplexer B Authentication Center Broadcast Broadcast Unit BSC Clock A Broadcast Broadcast Unit Broadcast Common Control Channel (GSM TS) Base station Control Function (BTS) Border Gate (GPRS)

1 · 1 · 428

BIE BIEC BIUA BPA BSC BSIC BSS BSSGP BTS CAE CAL CBC CBCH CBE CCCH CCU

Base Station Interface Equipment Base Station Interface Equipment (BSC) Base Station Interface Unit A Back Assembly Base Station Controller Base Transceiver Station Identity Code Base Station (sub)System Base Station System GPRS Protocol (GPRS) Base Transceiver Station Customer Application Engineering Current Alarm List (O&M) Cell Broadcast Center Cell Broadcast Channel (GSM TS) Cell Broadcast Entity Common Control Channel (GSM TS) Channel Coding Unit




Abbreviations and Acronyms [cont.]

CDMA CE CEK C/I CLK CLSI CMA CMDA CMFA R CRC CS CS CU DCE DCN DL

Code Division Multiple Access Control Element (BSC) Control Element Kernel Carrier to Interferer ratio Clock Custom Large Scale Integrated circuit Configuration Management Application (O&M) Common Memory Disk A Common Memory Flash A Common Processor (Type: RA, RC) Cyclic Redundancy Check Circuit Switching (Telecom) Coding Scheme (GPRS): CS-1, CS-2, CS-3, CS-4 Carrier Unit (BTS) Data Circuit Terminating Equipment Data Communication Network DownLink

1 · 1 · 429

DLS DMA DRFU DRX DSE DSN DTX DTC DTE EDGE EDA EI EML EPROM ETSI FPE FR

Data Load Segment Direct Memory Access Dual Rate Frame Unit Discontinuous Reception (GSM TS) Digital Switching Element Digital Switching Network Discontinuous Transmission (GSM TS) Digital Trunk Controller (Type: DTCA, DTCC) Data Terminal Equipment Enhanced Data rates for GSM Evolution Extended Dynamic Allocation Extension interface Element Management Level Erasable Programmable Read Only Memory European Telecom Standard Institute Functional and Protective Earth Full Rate (GSM TS)





FR FRDN FU FW GCR GGSN GMLC GMM GMSC GPRS GPU GS-1 GS-2 GSL GSM GSM TS HAL HDSL HDLC

Frame Relay (Telecom) Frame Relay Data Network (Telecom) Frame Unit (BTS) Firmware Group Call Gateway GPRS Node (GPRS) Gateway Mobile Location Center GPRS Mobility Management (GPRS) Gateway Mobile Switching Center General Packet Radio Service GPRS Packet Unit Group Switch of stage 1 (BSC) Group Switch of stage 2 (BSC) GPRS Signalling Link Global System for Mobile Communications GSM Technical Specification Historical Alarm List (O&M) High rate Digital Subscriber Line High Level Datalink Control

1 · 1 · 430

HLR HMI HO HR HW IDR ILCS IMT IND IP ISDN IT LA LAC LAN LED LEO LCS

Home Location Human Machine Interface HandOver Half Rate Hardware Internal Directed Retry ISDN Link Controller Installation and Maintenance Terminal (MFS) Indoor (BTS) Internet Protocol Integrated Services Data Network Intelligent Terminal Location Area (GSM TS) Location Area Code (GSM TS) Local Area Network Light Emitting Diode Low Earth Orbit (Satellite) Location Services





PCH PCM PCU PDCH PDN PDU PLL PLMN PMA PMC PPCH PRACH Prec PRC PSDN

Paging CHannel (GSM TS) Pulse Coded Modulation Packet Control Unit (GPRS) Packet Data CHannel Packet Data Network (Telecom) Protocol Data Unit (generic terminology) Phase Locked Loop Public Land Mobile Network Prompt Maintenance Alarm (O&M) Permanent Measurement Campaign (O&M) Packet Paging CHannel (GPRS) Packet Random Access CHannel (GPRS) Received Power Provisioning Radio Configuration (O&M) Packet Switching Data Network (Telecom)

1 · 1 · 431

PSTN PTP-CNLS QoS RA RACH RAM R RLC RLP RML RNO RNP RSL

Public Switching Telephone Network (Telecom) Point To Point CoNnectionLeSs data transfer (GPRS) Quality of Service Radio Access Random Access CHannel (GSM TS) Random Access Memory Radio Control Point Radio Link Control (GPRS) Radio Link Protocol (GSM TS) Radio Management Level Radio Network Optimisation Radio Network Planning Radio Signalling Link





RTS RxLev RxQual SACCH SAU SC SCC S SC SCSI SDCCH SDU SGSN SIEA

Radio Time Slot Received Level Received Quality Slow Associated Control Channel (GSM TS) Subrack assembly unit (BSC) Supervised Configuration (O&M) Serial Communication Controller Service Control Point Signalling Connection Control Part Small Computer Systems Interface Standalone Dedicated Control Channel (GSM TS) Service Data Unit (generic terminology) Serving GPRS Node (GPRS) SCSI Interface Extension A

1 · 1 · 432

SM SMLC SMP SMS SMS-CB SM-GMSC SRAM SRS SS7 SSD SSP SW SWEL TBF TAF

Submultiplexer Serving Mobile Location Center Service Management Point Short Message Service Short Message Service - Cell Broadcast Short Message Gateway Mobile Switching Center Static RAM SubRate Switch Signalling System ITU-T N°7 (ex CCITT) Solid State Disk Service Switching Point Software Switch Element Temporary Block Flow (GPRS) Terminal Adaptor Function





TC TC TCC TCH TCIL TCSM TCU TDMA TFO TFTS TLD TMN TRAC TRAU TRCU TRE TRS TRU

Transcoder Terminating Call Trunk Controller Chip Traffic CHannel (GSM TS) TransCoder Internal Link TransCoder / SubMultiplexer equipment TRX Control Unit (Type: TCUA, TCUC) Time Division Multiple Access Tandem Free Operation (TC) Terrestrial Flight Telecom Systems Top Level Design Telecommunication Management Network Trunk Access Circuit Transcoder and Rate Adapter Unit Transcoder Unit Transceiver Equipment Technical Requirement Specification Top Rack Unit

1 · 1 · 433

TRX TS TS TSS TSCA TSU TU UL UMTS USSD VBS VGCS VLR VPLMN VSWR WAN WAP WBC

Transceiver Time Slot Technical Specification (GSM TS) Time Space Switch Transmission Sub-System Controller A (BSC) Terminal Sub Unit (BSC) Terminal Unit (BSC) UpLink Universal Mobile Transmission System Unstructured Supplementary Services Data Voice Broadcast Service Voice Group Code Service Visitor Location Visited PLMN Voltage Standing Wave Ratio (BTS) Wide Area Network Wireless Application Protocol Wide Band Combiner




End of Module Basics

1 · 1 · 434




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