Lte Drive Test Introduction 2i5i2a

4G LTE

Drive Test Introduction Author

: Ray Khastur : http://www.linkedin.com/pub/ray-khastur/36/965/b7a

Drive Test Peripheral

LTE Dongle

Notebook

GPS

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 2

LTE Radio Parameter

LTE Main Radio Parameter PCI (0~503) RSRP (- 130 ~ -50) dBm

SINR (-20 ~ 30) dB MIMO (TM1, TM2, TM3, TM7)

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 4

UE State Information

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 5

Throughput Measurement

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 6

DL RB Used on High Speed Throughput

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 7

DL RB Used on Low Speed Throughput

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 8

LTE Access

Attach Request Procedure – Event List

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 10

Attach Request Procedure – L3 Message

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 11

UE Attach Procedure RACH

RRC Setup

Authentication

E-RAB

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 12

Access Failure Reasons Random access fail reasons: • Bad RF conditions ( SINR<-3 or RSRP<-120) • UE configuration parameter (Monitor the top-1 fail UE for analysis) • Enode-B configuration parameter (Parameter checking at the TOP-1 fail site) • Core-network configuration parameter (If all the site in one CN often fail)

Authentication will happen between UE and MME, EnodeB just transfer the information. So we have to check the “S1 interface message” in core-M2000. Authentication fail in three reasons: • UE did not all the information (4 messages). -----check the UE signal conditions. • Core-Network no reply “Initial UE context setup Req)-----UE and CN need to be check. • Core-Network release “S1 UE Context Rel_CMD”-----UE and CN need to be check.

RRC Setup Fail reasons: • Case-1: often fail by One UE: trace the UE and get the RF signal performance. Maybe cause by the UE signal or UE configuration setting. • Case-2: Often fail in one site by different UEs: Trouble shooting the problem site.

ERAB fail Reason: •Security mode negotiation problem (“RRC SEQUR Mode Fail” reply by UE)----UE problem •Security mode negotiation problem (No receive “RRC SECUR MODE CMP” from UE”---UE RF conditions. •UE CAP enquiry fail.(No receive “RRC_UE_CAP_RSP”from UE”----UE RF conditions. •RECFM not complete (No receive” RRC CONN RECFG CMP” from UE)----UE RF conditions.

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 13

LTE Neighboring Cell

Serving and Neighboring Cell UE

S_eNB

T_eNB

Core Network

Meas_RPRT S1AP_Handover_Required S1AP_Handover_Request S1AP_Handover_REQ_ACK S1AP_Handover_CMD RRC_CONN_RECFG (HO_CMD)

S1AP_eNB_Status_Transfer S1AP_MME_Status_Transfer RRC_CONN_RECFG_CMP S1AP_Handover_Notify (HO_CMP) S1AP_UE_CONTEXT_REL_CMD S1AP_UE_CONTEXT_REL_CMP RRC_CONN_RECFG RRC_CONN_RECFG_CMP

UU_interface

X2_interface

S1_interface

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 15

ANR vs UE capability : Inter-eNodeB 1. The source eNodeB delivers the intra-frequency measurement configuration to the UE, instructing the UE to measure neighboring cells that work on the frequencies specified in the measurement configuration. 2. The UE detects that the PCI of cell B meets the measurement requirements, and reports the PCI to the source eNodeB. 3. The source eNodeB checks whether its intra-RAT NCL includes the PCI of cell B. If so, the procedure ends. If not, the source eNodeB sends the measurement configuration to the UE, instructing the UE to read the ECGI, tracking area code (TAC), and PLMN ID list of cell B. 4. The source eNodeB allows the UE to read these parameters over the broadcast channel (BCH). 5. The UE reports the obtained parameter values to the source eNodeB. Notes: ANR features of an UE will effect the capability of the UE to read the ECGI, TAC and other information of the target cell. Thus, failure to do so the target cell information can’t be read. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 16

ANR vs UE capability : Intra-eNodeB 1. The source eNodeB delivers the intra-frequency measurement configuration to the UE, instructing the UE to measure neighboring cells that work on the frequencies specified in the measurement configuration. 2. The UE detects that the PCI of target cell (Cell A) meets the measurement requirements, and reports the PCI to the source cell (Cell B). Due to the source cell and target cell are located under the same BBU board, thus target cell information can be search and obtain internally referring to the PCI. Therefore although UE doesn’t ANR features, it doesn’t affect the reading of ECGI, TAC and other information of the target cell which required for the creation of NCL.

4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 17