RF4G LTE Drive Test Tools and Essential Parameters
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In the world of mobile networks, ensuring optimal performance and Quality of Service (QoS) is crucial. This is where 4G LTE drive testing plays a vital role. Drive test tools help network engineers analyze and optimize 4G LTE networks, ensuring seamless connectivity, faster speeds, and minimal disruptions. From signal strength to handover performance, these tests measure key parameters critical to delivering an excellent user experience.
In this article, we’ll explore the most commonly used drive test tools & scanners and the essential parameters tested during 4G LTE drive testing. Drive tests are useful for various reasons:
- 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 (Circuit Switched) and PS (Packet Switched) calls. This is referred to as stability tests.
An LTE drive test system comprises LTE UE (User Equipment) hardware and software which takes care of decoding the eNB (evolved NodeB) compliant signal. It also houses a drive test software application to perform various measurements in an easy-to-display manner. This helps LTE RF engineers and LTE network engineers troubleshoot problems during the testing and installation phase.
LTE Drive Test Parameters
The following table lists measurements performed by an LTE drive test system. JDS Uniphase Corporation has developed LTE drive test software (Model: JDSU-E6474A) and a 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.
| LTE Measurements | Description |
|---|---|
| Protocol Log (RRC log, NAS log) | This helps analyze cell-related system information 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 received signal quality. |
| Channel Quality Measurements - SINR/CINR/SNR | This is proprietary measurement, and it is manufacturer-specific. |
| DL-SCH and UL-SCH throughput measurements | Downlink Shared Channel (DL-SCH) and Uplink Shared Channel (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 (BLER) UE is achieving while on UL (Uplink) and DL (Downlink) 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 | Wideband (WB) and Narrowband (NB) Channel Quality Information measurement of channel quality on allocated frequencies. It is used for link adaption purposes. |
| Number of Tx/Rx paths | It will determine the active MIMO (Multiple-Input Multiple-Output) mode. |
| UE transmit power | Helps determine the power used by the UE for efficient operation. |
| User application throughput | It will help in estimating the LTE throughput achievable by the LTE network for various applications. |
| Ping related measurements | It will help measure the latency of the network. |
LTE Drive Test Tools | R&S LTE Drive Test Scanner
Let’s understand various drive test tools available for the LTE system. JDSU has developed drive test solutions for the LTE system, which includes the JDSU E6474A wireless network optimization system and the JDSU W1314A measurement receiver and other modules/software. They have phone-based drive tests and receiver-based drive tests for LTE.
RantCell has developed the following drive test tools for similar needs in 4G LTE as well as other cellular technologies:
- RF drive test tool to optimize the mobile network.
- Cell tower QoE monitoring.
- Identify and monitor QoE issues/events on 2G, 3G, LTE, and CDMA networks.
- RAN (Radio Access Network) network cell site survey.
- Cell tower signal and range measurement.
LTE Test Scanner R&S
R&S has developed LTE drive test scanner model numbers R&S ® TSMW and R&S ® TSME, which has the following features:
- The scanner supports TD-LTE and LTE FDD frame structures/topologies.
- There is no limitation on the number of cells to be measured. It supports scanning all 504 Physical Cell IDs.
- LTE drive test scanner TSMW supports MIMO measurements with the R&S ® TSMW-K30 MIMO option.
- Measures MIB (Master Information Block) and SIB (System Information Block) information transmitted by eNBs.
- Supports other multiple RATs, e.g., GSM, WCDMA, CDMA200, 1xEVDO, WiMAX 802.16e, TETRA, TD-SCDMA, LTE FDD, TD-LTE, RF Powerscan, etc.
Conclusion
4G LTE drive testing is indispensable for maintaining high network performance and quality. With the help of advanced drive test tools, engineers can assess and optimize critical parameters like signal strength, coverage, and data throughput. These tests ensure that users experience reliable, high-speed connectivity in any environment. As mobile networks evolve, drive testing will remain a cornerstone for delivering superior network performance.
