Learn the basic RF Parameter for LTE Drive Test

1. Author : Ray Khastur
: http://www.linkedin.com/pub/ray-khastur/36/965/b7a
4G LTE
Drive Test Introduction

2. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 2
Drive Test Peripheral
Notebook
GPS
LTE Dongle

3. LTE Radio Parameter

4. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 4
LTE Main Radio Parameter
PCI (0~503)
RSRP (- 130 ~ -50)
dBm
SINR (-20 ~ 30) dB
MIMO (TM1,
TM2, TM3, TM7)

5. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 5
UE State Information

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

7. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 7
DL RB Used on High Speed Throughput

8. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 8
DL RB Used on Low Speed Throughput

9. LTE Access

10. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 10
Attach Request Procedure – Event List

11. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 11
Attach Request Procedure – L3 Message

12. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 12
UE Attach Procedure
RACH
RRC Setup
Authentication
E-RAB

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

14. LTE Neighboring Cell

15. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 15
Serving and Neighboring Cell
Meas_RPRT
S1AP_Handover_Required
S1AP_Handover_CMD
RRC_CONN_RECFG
(HO_CMD) S1AP_eNB_Status_Transfer
UE S_eNB T_eNB Core Network
S1AP_Handover_Notify
S1AP_UE_CONTEXT_REL_CMD
RRC_CONN_RECFG_CMP
(HO_CMP)
RRC_CONN_RECFG
RRC_CONN_RECFG_CMP
UU_interface X2_interface S1_interface
S1AP_Handover_REQ_ACK
S1AP_MME_Status_Transfer
S1AP_UE_CONTEXT_REL_CMP
S1AP_Handover_Request

16. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 16
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.

17. 4G LTE Drive Test Introduction @ Floatway Learning Centre , slide number 17
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 support 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.
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).
ANR vs UE capability : Intra-eNodeB