Conformance testing is designed to help eliminate problems with user equipment that would would impact the functioning and performance of wireless networks. 3GPP is the body that has set the standards by which equipment is both designed and tested in order to meet those standards. OEMs, chipset and software component vendors, test houses and network operators all make use of 3GPP conformance testing, in addition to other tests such as carrier acceptance testing — which requires that a device meet an additional set of conditions set by the mobile carriers themselves before they will allow it to be sold and operate on their networks.
3GPP conformance testing is actually a specific group of tests which involve connecting wireless device to a system of wireless test equipment, and then performing specific tests that are mandated by 3GPP. Some of them involve the radio frequencies on which the device operates, some of them are protocol-based tests; some of them are conducted over-the-air, and there may also be testing of device SIM cards. The Global Certification Forum, one of two major organizations for the 3GPP-based device certification, also requires that the device be drive-tested. The pass-fail limits for 3GPP conformance testing are one of the test determinations made by 3GPP in the course of developing the tests.
“Without passing these tests, you can’t take your phone to market and sell it,” said Mike Barrick, business development manager for wireless at test company Anritsu. He noted that protocol and RF tests are the main focuses of the 3GPP conformance testing, however.
3GPP provides the standards for technologies including GSM, W-CDMA and LTE. The body also provides the test specifications for UEs in terms of radio frequency, protocol and USIM (Universal Subscriber Identity Module) testing.
The 3GPP conformance tests, and other conformance tests developed by forums including the Open Mobile Alliance or the European Telecommunications Standards Institute (ETSI). The device certification groups — PTCRB (which serves mostly North American carriers), the GCF (mostly European carriers) and the CDMA Certification Forum (for devices using CDMA2000) then provide a framework in which certain combinations of tests are performed as required in order for a device to receive a particular group’s certification. The GCF and CCF recently announced that they are working together on a single certification process for mobile devices that encompass any combination of 3GPP and 3GPP2 technologies, and shared a booth at the most recent CTIA show. CDMA2000 is a 3GPP2 technology, and the move was driven by the continued evolution of networks away from 2G and 3G technologies toward LTE — as well as devices making use of multiple technologies in order to function on both legacy networks and LTE.
3GPP has a number of working groups that develop various pieces of the technology. Its RAN (Radio Access Network) WG5 develops mobile terminal conformance testing, for interactions between the user equipment and the radio interface. According to the group’s Web site, that conformance testing includes RF conformance tests for TDD and FDD LTE; Radio Resource Management (RRM) conformance tests for TDD and FDD; tests for the air interfaces, including Universal Terrestrial Radio Access (UTRA), e-UTRA in LTE, and IMS and NAS protocol tests; and others. The group coordinates with other 3GPP working groups in order to develop the conformance tests.
Barrick said that the system for developing the test cases for 3GPP conformance testing can take six months to a year, from when the standards body develops the conformance specifications it wants tested, to the development of test cases by test houses and having those test cases validated in order to be approved by the GCF or the PTCRB. Third party labs must perform the testing so that testing companies have no direct influence on the test case validation results, Barrick noted.
Other sources: 3GPP TSG RAN WG5 page: www.3gpp.org/RAN5-Mobile-terminal-conformance
