Research on TD-SCDMA Mobile Terminal test

Summary:

The development strategy of the third generation mobile communication system based on CDMA2000 1X technology, the conformance test of mobile terminals of category CDMA 1X in China, it is necessary to test the TD-SCDMA Mobile terminal. In addition to the principle of consistency test and the method of conformance testing, this paper also puts forward the development background and limitation of TD-SCDMA in China.

Background:

In recent years, conformance testing has been a very important and rapid development field in the world. Conformance testing is the consistency between the verification protocol implementation and the corresponding protocol standard. For example: At present, the CDG test of CDMA 1X carried out in the Mtnet laboratory of the Ministry of Information Industry Telecommunication Institute is a conformance test. This test is to adapt to the development of CDMA cellular technology in China, to ensure that different manufacturers of systems and mobile units in the network can be interoperable, to ensure that China's domestic development can be based on, for operators to ensure quality. As China's first proposed international 3G standard with independent intellectual property rights, TD-SCDMA adopts the advanced technology of smart antenna, relay switching, dynamic channel allocation and uplink synchronization, which shows many incomparable advantages from the beginning. With many concerns and joint efforts, TD-SCDMA technology has made rapid progress: the Ministry of Information Industry Mtnet Laboratories and the main research and development institutions of the enterprise test, it also successfully went to the outdoor demonstrations. With the advent of 3G standards, the study of terminal standards and terminal system equipment testing has become a priority task. Refer to 3GPP files, WCDMA test Specification and UE test Instrument development progress, combined with the information Industry Department Mtnet Laboratory of the existing environment, the development of China's national conditions for the test program is steadily underway. In the completion of basic telecommunications services and data services, to play TD-SCDMA-specific technology to complete more powerful functions. Among them, the solution of TD-SCDMA Mobile Terminal Equipment Protocol inconsistency problem will become the whole system evolution process of a factor that can not be ignored. Therefore, it is of great significance to carry out the research on the conformance testing technology of TD-SCDMA mobile terminals, and to provide standard and practical conformance testing methods and tools to accurately verify the technology, signaling and performance requirements of mobile terminals. (Computer science)

The principle of conformance testing

Protocol conformance testing is essentially the use of a set of test sequences, in a certain network environment, the implementation of the Protocol (IUT) for black-box testing, by comparing the actual output of the IUT and the expected output of the similarities and differences, to determine the extent of IUT in accordance with the description of the agreement, Establish the success rate of IUT through conformance testing in interconnection. According to the conformance test methodology, the test standard includes 3 parts: Abstract test Set (ATS), Protocol Implementation Conformance specification (PICS), and Protocol Implementation additional information (PIXIT).

From the specification, is the text that describes the test process. Each ATS prescribes the testing purposes, content, and procedures of a standard protocol, so the formation of ATS determines the quality of the test. Pics describes the implementation requirements, capabilities and implementation of options, Pixit provides the protocol parameters that must be indicated when testing, and its specific steps are as follows.

①iut's pics analysis Iut iut static consistency requires an SCR check to analyze whether the pics is consistent with the specified SCR specification.

The ② Test selection pics and pixit are used to select the appropriate test cases from the consistency test set, and use the information provided by Pixit to quantify these test cases, generate the executable test set ETS from ATS, and eventually produce the parameterized executable test set ETS.

③ test execution uses ETS for conformance testing of IUT, resulting in detailed test reports.

The final consistency test of ④iut combines known pics and pixit analysis and test results to obtain IUT consistent conclusions about standard requirements, recorded in conformance testing reports.

Second, wireless interface protocol

The wireless interface of TD-SCDMA mobile communication system is divided into 3 protocol layers: Physical layer (L1), Data link layer (L2) and Network layer (L3).

The physical layer is composed of downlink physical channel and uplink physical channel; the data link layer accepts the service of the physical layer and provides services to the network layer, which is divided into the media Access sub Layer (MAC), the Wireless Link Control sub Layer (RLC), the packet Data set Protocol sub Layer (PDCP) and the broadcast/multicast Control child layer (BMC). The MAC sub layer controls the access signaling process of the wireless channel. The RLC child layer provides logical link control for the wireless interface. The BMC-SAP child layer provides broadcast/multicast services for public user data on the user plane of the wireless interface. The PDCP of the upper layer can be mapped into the low-level wireless interface protocol, which can make the upper protocol transparent, and the PDCP layer also provides the compression and decompression of protocol control information. Network layer and RLC are divided into control plane and user plane, PDCP and BMC exist only in the user plane. The lowest layer of the network layer control plane is the wireless resource management sub Layer (RRC), responsible for processing the signaling between the mobile terminal and the Wireless access Network (RAN) on the control surface of the network layer, the upper level of the network layer control plane is the mobility Management sub Layer (MM), the call Control sub Layer (CC), and the packet switching mobility Management sub Layer (GMM) and session Management sub-layer (SM), which belongs to the non-access layer.

Introduction of test methods

From the TD-SCDMA technology, should not only provide users with ordinary telephone services and functions should also be based on their own wireless performance indicators and supported the protocol more secure and richer business. In a general sense, terminal testing should include the following:

• Business Function Testing

• Wireless Indicator test

• Protocol Signaling Test

• Other tests

1. Business function test

(1) Basic REQUIREMENTS for UE human-machine interface

As the call of the caller number display, call progress signal instructions, the national/PLMN instructions, keyboard, switch, Chinese support ability, telephone number storage function, signal intensity indicator, etc. as the basic functions of the terminal can be called. These are the basic requirements for commercial terminals.

(2) Business test

Including basic telecommunications services, bearer services, concurrent operations and supplementary services.

• Basic telecommunications services include voice services, emergency calls and point-to-point short message operations.

• Bearer services: Circuit Domain Multimedia services: should be able to support compatible h.324m Videophone terminal access, and PLMN or PSTN, ISDN network h.324m videophone terminal, multimedia videophone communication. Multimedia service is carried by BS30 bearer service.

cs/ps Concurrent Business AMR Voice and PS data coexistence business combination test.

• Complementary business such as unconditional call forwarding, before and after the rush and no answer before the transfer.

(3) Roaming function test

It is mainly divided into roaming and td-scdma/gsm between the TD-SCDMA systems of different manufacturers

2 Wireless Indicator test

TD-SCDMA is also internationally recognized as the 3G standard, so the wireless indicators are roughly the same as other standards, including three parts:

(1) Transmitter testing, including UE maximum output power, frequency tolerance, minimum output power, bandwidth consumption, adjacent leakage suppression ratio, stray radiation, emission intermodulation, vector amplitude error (EVM), peak code area error.

(2) receiver test, including reference sensitivity level, maximum input level, adjacent channel selectivity, stray radiation and so on.

(3) Wireless performance test, including the demodulation under the condition of static propagation, the performance requirements of DCH demodulation under different fading conditions.

TD-SCDMA's unique smart antenna technology and bandwidth is significantly different, so that the test project and indicators are somewhat different, the following list only a few of the more distinctive items and points out the difference.

1) Maximum output power

The maximum output power for different power levels is not the same, the domestic is the use of power level 3, single code channel 12.2kbps maximum output power tolerance for +21±2.7DBM, dual-code 12.2kbps maximum output power of the tolerance is +18±2.7dbm.

2) Frequency tolerance

The TDD model does not require that the terminal achieve maximum transmit power when testing, only when the base station simulator transmitter power is -108DBM, the frequency error is required in * (0,1ppm+10hz).

3) adjacent channel leakage suppression ratio (ACLR)

For the 1.28Mcps LCR-TDD mode, the bandwidth is 1.6MHz. So the test points are selected as ue-channel±1.6 MHz and ue-channel±3.2 MHz.

4) Emission intermodulation

For LCR-TDD mode, the frequency offset of the interference signal CW is ±1.6mhz and ±3.2mhz.

5) Uplink power control

This test project is a unique test project for TDD mode, and the main test is to verify that the UE receiver is capable of achieving the required link quality on the network with as little uplink power as possible.

This test initially sets the pccpch power to -60DBM, adjusts the DPCH constant to enable the UE to transmit the power to reach 5dBm, and stabilizes 5s, changes the pccpch power to -70dbm. Because a frame of 1.28Mcps TDD mode contains two frames, the transmit power of the UE is measured separately at the first and last slots of two frames. When the power of pccpch has just changed, the first time slot of two frames is 15dBm, and the last one is 5dBm. In the 20th frame after the change, the first time slot emission power of two frames is 15dBm, and the last one has 15dBm.

3. Protocol Signaling Test

The Protocol Signaling Test Section guarantees the consistency and normalization of UE's signaling and protocol. This part of the test mainly includes three parts: The basic function of 3G network, the basic process of circuit domain and the basic process of grouping domain.