Layer 1 Tests Made Easy for 3G WCDMA and HSDPA

Europe : The layer 1 test software from Rohde & Schwarz is a flexible test environment for layer 1 implementations in WCDMA and HSDPA user equipment. It offers numerous possible configurations for the transport channels defined in these standards. An additional scripting interface facilitates the automated execution of test scenarios. The layer 1 test software is available as a software option for the R&S CRTU-W and R&S CRTU-M platforms.

In accordance with the WCDMA standard, services with different quality requirements can be bundled on the same resources in the physical layer (layer 1); a different channel combination can be selected for each service. HSDPA adds to the list of tasks for layer 1. Chipset manufacturers for WCDMA and HSDPA terminals must therefore thoroughly test the layer 1 implementation before it is integrated.

For this purpose, Rohde & Schwarz offers a layer 1 test software option for the tried-and-tested R&S CRTU-W hardware platform and the more economical R&S CRTU-M. The test software simulates the layer 1 behavior of a WCDMA base station. It can generate complex downlink signals at layer 1 and test their reception and processing in the layer 1 UE implementation under test. In the uplink, the layer 1 test software analyzes the signals received from the DUT. Moreover, the software tests for correct interaction between the downlink and the uplink in the DUT, which is indispensable in HSDPA tests. The DUT is operated in non-signaling mode, where no signaling by higher layers is required.

The test software verifies layer 1 functions such as compressed mode, closed loop power control and transmit diversity. Above all, it provides numerous capabilities for configuring the transport channels defined in the WCDMA standard and then for creating different channel combinations. In the physical layer, the HSDPA standard provides for two new channels in the downlink and one new channel in the uplink. Owing to the layer 1 test software, these new channels are user-configurable; even HSDPA specifics such as adaptive modulation and hybrid ARQ protocol can be taken into account. Thus, virtually any test scenario can be generated. In addition to manual operation, the layer 1 test software supports a scripting interface based on the Microsoft COM standard, enabling regression tests. Automated test scripts can be prepared in Visual Basic, for example, and predefined channels integrated into the scripts.

The test software allows a test scenario to be modified while the test is in progress, without the need for recompilation. Configuring the Windows-based GUI and immediately activating parameter changes requires no special programming knowledge.

The layer 1 test software option for R&S CRTU-W and R&S CRTU-M is now available from Rohde & Schwarz. Both of these hardware platforms can be upgraded to fully configured protocol test environments; they can thus be flexibly used, from layer 1 development and protocol integration through to conformance tests. Plus, they are ready for high speed uplink packet access (HSUPA).