Users use the terminal to experience the functions provided by the network. Therefore, the maturity and quality of the terminal are directly related to the promotion and development of the mobile communication service itself. This is especially important for TD-SCDMA, which was developed in China alone. With the official release of 3G licenses and the continuous expansion of TD-SCDMA networks, policy factors and network coverage issues will be solved perfectly, and the performance and quality of the terminals themselves will become the most concerned topic. Test instruments are a very critical device for ensuring the quality of the terminal.
For operators, it is impossible to achieve the same coverage as GSM for TD-SCDMA networks. Existing 2G networks are needed to provide alternative services in areas that cannot be covered by TD-SCDMA. Therefore, dual-mode terminals compatible with both TD-SCDMA/GSM systems have become an inevitable trend. Correspondingly, TD-SCDMA terminal test instruments need to increase the GSM measurement capability to improve test efficiency.
The non-signaling mode (only measuring RF indicators, not establishing network connection and call test) used in some TD-SCDMA terminal production tests is suitable for calibration and RF measurement, and is not suitable for final testing of TD-SCDMA terminals. Because the TD-SCDMA terminal is still relatively mature, it is only tested in the non-signaling mode, and may encounter problems during actual calls. Therefore, the entire signaling test mode is necessary for the TD-SCDMA terminal that is still in its infancy.
For the application service and functional testing and protocol testing of the terminal, there is currently no corresponding network emulator, and the actual base station is used to construct the analog network. For the incomparable conformance test (protocol, application, USIM, etc.) of the mobile terminal, it is necessary to ensure the uniformity of the test conditions based on the simulated network environment of the base station emulator.
TD-SCDMA/TD-HSDPA terminal RF testThe RF test of TD-SCDMA terminal mainly includes the following two aspects: (1) R&D test—including board-level and complete machine test verification of the terminal design process to ensure that the main indicators of the terminal meet the requirements of the specification. (2) Production line testing – including non-signaling calibration and signaling connection testing to ensure stable performance of the final terminal product.
The radio transmission and reception indicators that the TD-SCDMA terminal needs to conform to are specified in the 3GPP TS34.122 specification, including transmitter characteristics, receiver characteristics, performance, radio resource management, and HSDPA performance.
R&D engineers need to adjust the parameters in time to follow the changes in the specifications. In the production line test, it is also necessary to improve the efficiency of the test. To meet these challenges, test instruments must provide test items that fully comply with regulatory requirements, while allowing users to flexibly define and configure.
Anli's MT8820B-based TD-SCDMA/HSDPA terminal RF test solution fully supports the RF test items required by the specification (Table 1), and provides batch test functions, while measuring multiple test items. In addition, Anritsu has a unique dual-port solution (Figure 1). One instrument can simultaneously support the testing of two mobile phones, greatly improving the efficiency of production testing, saving space and cost.
Figure 1: Anritsu has a unique dual-port solution that allows one instrument to simultaneously test two phones.
Table 1: Main items of TD-SCDMA/TD-HSDPA terminal RF measurement.
The MT8820B can perform RF measurement/calibration in non-signaling mode, as well as continuous call test in signaling mode, end-to-end call test, and video telephony test. Corresponding to the latest TD-HSDPA terminal, MT8820B can perform corresponding connection test, data throughput test and CQI measurement. When measuring HSDPA throughput using the RMC signal, it supports all HS-DSCH levels including a maximum rate of 2.8 Mbps.
Anritsu's MT8820B also supports WCDMA/HSPA, GSM/GPRS/EDGE, CDMA2000/1XEVDO and other communication systems, which can support stable switching from TD-SCDMA to GSM systems. During the test, the dual-mode terminal can easily switch from the TD-SCDMA connection state to the GSM connection state, and no longer needs to be disconnected and reconnected.
Figure 2: The MT8820B supports stable switching from TD-SCDMA to GSM systems.
TD-SCDMA terminal application testWith the increasing use of mobile phone functions, especially the popularization of new functions such as mobile Internet access and data services, the complexity of mobile phone applications has increased, and the corresponding faults and problems have also increased. Therefore, a series of application tests must be performed on the mobile terminal, including parallel testing, extreme testing, etc., to test the support level of the application layer software of the mobile phone to services such as MMS and WAP, and the processing capability of the multimedia data.
Anritsu's MD8470A can support the simulation of a variety of 2G/3G mobile communication systems including TD-SCDMA, providing a very powerful test environment and providing a graphical interface for user convenience. The MD8470A Signaling Tester supports voice, SMS, data communication, MMS, video telephony, supplementary services and other business tests. The MD8470A can also be used with companies such as SETCOM to form an application that complies with the 3GPP standard and the USIM conformance test system.
Another area of ​​application for the MD8470A is the protocol testing of TD-SCDMA. R&D personnel can write protocol test scripts in C language, freely define the parameters of the physical layer, MAC layer, and RLC layer, and write the protocol flow arbitrarily. The message sent by the base station side is completely defined by the user, and this is difficult to achieve in an actual network. The signaling process can be monitored at any time during the test, making it easy to troubleshoot and debug. At present, only the MD8470A can complete the above TD-SCDMA protocol test function (Figure 3).
Figure 3: The TD-SCDMA emulator is a required test tool for each stage of end product development.
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