LTE Drive Tests Basics
This tutorial section on LTE basics covers following sub topics:
Main page features terminologies Frame TDD FDD Channel types PHY stack throughput VoLTE CA cell search network entry Timers PSS vs SSS Security LTE Bands EARFCN Hotspot router
This page covers measurements performed during LTE drive test. It mentions LTE drive test scanner hardware and drive test software.
The Drive tests are useful for various reasons as mentioned below:
• It helps test the system before deployment.
• To determine any RF signal strength related issues.
• To determine the cells available in the region for the target RAT(Radio Access Technology) or any other RATs.
• To determine the functioning of the system(e.g. LTE) along with other RATs. (GSM,UMTS)
• To find out any issues during long duration CS and PS call.This is referred as stability tests. Refer basics of RF drive test.
LTE drive test system composed of LTE UE hardware and software which takes care of decoding the eNB compliant signal. It also houses drive test software application to perform various measurements in a easy to display manner. This helps LTE RF engineers and LTE network engineers troubleshoot problems during the testing and installation phase.
Following table mentions lists of measurements performed by such LTE drive test system. JDS Uniphase Corporation has developed LTE drive test software(Model: JDSU-E6474A) and hardware module measurement receiver(Model:JDSU W1314A) for their drive test system solution. The solution covers multiple bands and supports multiple technologies. The drive test system supports multiple RATs e.g. GSM, UMTS, HSPA, GPRS, TD-SCDMA, iDEN, WiMAX and LTE. Following LTE drive test measurements are performed by JDSU solution.
|Protocol Log(RRC log, NAS log)||This helps analyze the cell related system informations and broadcast messages and troubleshoot timing related events|
|Physical Cell-ID/E-ARFCN||This helps determine active and powered on cells i.e. base stations or eNBs|
|RSRP(Reference Signal Received Power) in dBm||It measures cell site received signal coverage|
|RSRQ(Reference Signal Received Quality) in dB||It measures cell site reecived signal quality|
|Channel Quality Measurements-SINR/CINR/SNR||This is proprietary measurements and it is manufacturer specific.|
|DL-SCH and UL-SCH throughput||measurements on the shared channel used by LTE UE on uplink and downlink.|
|DL-SCH and UL-SCH BLER||Block Error Rate UE is achieving while on UL and DL channels.|
|DL/UL resource blocks||Shared channels allocated to UE by the LTE scheduler operating in eNB.|
|DL/UL modulation and coding||Supported modulations such as BPSK, QPSK, 16QAM or 64QAM based on network conditions|
|WB/NB Channel Quality Information||measurement if channel quality on allocated frequencies. It is used for link adaption purpose.|
|Number of Tx/Rx paths||It will determine active MIMO mode.|
|UE transmit power||Help determine power used by the UE for efficient operation.|
|User application throughput||It will help in estimation of LTE throughput achivable by the LTE network for various applications.|
|Ping related measurements||It will help measure latency of the network.|
R&S LTE Drive Test Scannerfig.1
R&S has developed LTE drive test scanner model numbers R&S®TSMW
and R&S®TSME, which has following features:
• The scanner supports TD-LTE and LTE FDD frame structures/topologies.
• There is no limitation on number of cells to be measured. It supports scanning of all the 504 Physical Cell IDs.
• LTE drive test scanner TSMW supports MIMO measurements with R&S®TSMW-K30 MIMO option.
• Measures MIB and SIB informations transmitted by eNBs, refer LTE system information blocks for more information on these messages.
• Supports for other multiple RATs e.g. GSM, WCDMA, CDMA200, 1xEVDO, WiMAX 802.16e, TETRA, TD-SCDMA, LTE FDD, TD-LTE, RF Powerscan etc.
LTE RELATED RESOURCES
Difference between SC-FDMA and OFDMA
LTE Cyclic Delay Diversity
LTE eNodeB Physical Layer Measurements
LTE EPC Network Inerfaces
LTE UE Physical Layer Measurements
LTE Bearer types
LTE UE Event Measurement Reporting
LTE RSRP vs RSRQ
LTE Signalling radio bearers
LTE EPS mobility management states
LTE EPS connection management states
LTE UE cell selection
LTE UE PLMN selection
LTE UE Paging Procedure
LTE CQI vs PMI vs RI
LTE RNTI vs GUTI
LTE Security Basics