Europe : Two protocol testers, the R&S CRTU-W for UMTS and the R&S CRTU-G for GSM, can be used for the development of mobile dual-mode terminals. The R&S CRTU-WA03 software option makes it possible even at this stage to design custom signaling tests that simulate different UMTS-to-GSM handover scenarios. Both voice and data transmission can be tested. The software is the expansion of the R&S CRTU-W, which has already proven itself in conformance testing with its user-friendly TTCN interface.

The R&S CRTU-W, with its C++ programming interface R&S CRTU-WT02 and its official tree and tabular combined notation (TTCN) test cases, is already being successfully used in development for testing UMTS terminals. Now, however, the research and development laboratories of mobile phone companies and network providers also need a tool for testing the interoperability of 2G to 3G networks in custom signaling scenarios. Rohde & Schwarz has developed the R&S CRTU-WA03 software option to meet this need.

Users can perform such tests with the help of the extensive GSM/GPRS/EDGE function library of the Protocol Tester R&S CRTU-G, which was integrated into the UMTS medium level application programming interface (MLAPI) as C++ modules. As with the C++ MLAPI, these new modules can also be used in the GERAN protocol stack as a simple and time-saving means of generating signaling scenarios at layer 3. All underlying channel structures are taken into account. Even deliberately incorrect settings of the lower layers can be configured.

Complex processes can be combined in macros and make programming more efficient, as do predefined sample scenarios. Besides the signaling, voice or data applications can also be included in the test. Furthermore, cell reselection within the two networks and InterRAT measurements using the compressed mode at the UMTS end are available.

The R&S Message Composer, a graphical tool, has been implemented to help development engineers configure not only UTRAN-specific but also GERAN-specific messages. All actions carried out within a scenario as well as all messages sent are written to log files and can be visualized by means of the
R&S Message Analyzer. It automatically combines and sorts the UMTS and GERAN signaling data, allowing it to be analyzed at a glance.

The complete system consists of the two Protocol Testers R&S CRTU-W and R&S CRTU-G and the flexible C++ MLAPI R&S CRTU-WT02. The new R&S CRTU-WA03 software option for the MLAPI is now available from Rohde & Schwarz.