New CMW500s Make the Connection for Wireless Devices

With many more products incorporating cellular radios, it’s become essential for Elite to have the very best equipment in place to enable wireless connectivity for items under test.  This is especially true for those devices that integrate cellular modular radios.  To support this growing need, Elite has put in place three CMW500 Radio Communication cellular base station emulators from Rohde & Schwarz.

Elite’s CMW500s are in constant use around the lab to support all types of Automotive EMC, Commercial EMC, and Antenna Over-The-Air (OTA) Performance test requirements:

1) Quick and Reliable Cellular Calls.  Test items that incorporate cellular radios typically have to be evaluated while having a live cellular communication link. In the past, the cell links were simply made as an over-the-air connection to a local AT&T, Verizon, etc. tower, but these connections were not always reliable and required configuration of the phone and software for this specific purpose. In addition, because test items are often in shielded enclosures or due to the type of testing performed, the remote cell call link was not as stable as was needed to run a compliance test. 

By using the CMW500 instead of linking to an actual cell tower, the cellular channel configuration can be precisely controlled. Elite engineers can select the uplink and downlink frequency bands, transmit power level, and optimize the positioning of the base emulator antenna proximity to the test item.

2) Immunity Testing Requires Cellular Bit Error Rate Pass/Fail Monitoring.  Some regulatory harmonized standards require not only a cellular link but also specify pass/fail criteria for device performance. An example is EN 301 489-52 which is the cellular user equipment EMC standard for the European CE Mark Radio Equipment Directive. This standard specifies that the channel throughput shall not degrade more than by a 5% Bit Error Rate (BER or BLER) during immunity testing.  The only reliable means to configure this test and measure the BER/BLER metric is with a base station emulator like the CMW500.
 
3) Cellular Channel & Power Level Configuration for Emissions Verification.  New FCC requirements state cell modular radios integrated into a digital host must be measured for spurious emissions at specified frequencies and in a particular mode, ie WCDMA, LTE, etc.  Cellular AT commands are certainly one means to configure the radio, but the CMW500 is by far the most efficient and reliable means to enable the cell call to a designated frequency and operating condition. The requirement for verification of spurious emissions and intermodulation products are stated in FCC Guidance Document for Modular Transmitters (KDB 996369 D04) and in the ETSI Integration Guide EN 203 367. The CMW500 is used in these applications to configure the modular cell radio for the mode required for testing.

4) Other uses for the CMW500 are to provide the paired transmitted signal during a receiver blocking tests.  Receiver blocking requires a properly formatted signal be sent to the test item receiver while an interfering signal on an adjacent frequency is combined at the test item receiver input port.   For receiver blocking tests such as in EN 300 328 or EN 301 908 the CMW500 is an ideal source for a very stable and reliable the paired signal.  

For cellular boosters certification applications, a cell modulated signal is required as part of the certification testing suite.  The CMW500 is available to generate the necessary cellular modulations and apply the signal and at the required power level.

5) Besides cellular signals, the CMW500 also provides WiFi access point emulation and is a Bluetooth emulator as well.  

If your product incorporates a cellular wireless device (or WiFi and Bluetooth), then contact Elite today to learn more about using a CMW500 for a reliable and easily configurable cellular link.