Rohde & Schwarz Adds Bluetooth Low-energy Test Mode to Popular Connectivity Testers

With many wireless technologies available to designers, it can be difficult to choose the right protocol for an IoT-geared design.

Rohde & Schwarz is aiming to simplify the testing process for BLE devices with a new Bluetooth low-energy test mode or BLE 5.0, based on the CMW platform, that allows developers to "perform all RF and pre-conformance tests on their Bluetooth LE components via the air interface (OTA)."

In this article, we will look at the Rohde & Schwarz CMW platform connectivity tester and why a device like this could be useful for developing your next Bluetooth LE product. 

 

Bluetooth Requirements

Not any device can be stamped with the official Bluetooth logo. There are strict requirements around its use.

According to R&S's resource on Bluetooth testing with the CMW testers, the first requirement is that any company that wishes to integrate Bluetooth into its product must be a member of the Bluetooth SIG.

 

Diagram of design, qualification, and manufacturing setups for BLE devices. Image used courtesy of Rohde & Schwarz

 

The product must also go under a number of tests to ensure that it conforms to all standards. These include RF conformance, protocol, profile, and interoperability testing. Once these requirements have been met, the product can be stamped with the official Bluetooth logo.

The other series of tests required by a product include EMC conformity to ensure that the product meets the regulations laid out in laws such as FCC and CE.

Getting a product tested for sale is required to go through a national certification process body which itself must be certified by Bluetooth SIG.

 

R&S CMW All-in-One Platform

Since product testing is an expensive step with no guarantee of passing, pretesting can save a production team time and funds.

Rohde & Schwarz offers a range of CMW models to provide tests needed during the entire development process from R&D to pre-qualification. The R&S CMW platform meets all standards and requirements laid out in the Bluetooth qualification scheme, which includes validating RF test coverage for Bluetooth Classic, Bluetooth LE, and Bluetooth 5.2.

 

The CMW platform's wireless device testing. Image used courtesy of Rohde & Schwarz

 

Parametric Testing

Another major benefit to the R&S CWM platform is its parametric nature whereby individual parameters can be changed to provide different testing environments and settings. This also means that Bluetooth products can be tuned and improved during the development stages to improve connectivity and power consumption. 

 

Integrated Spectrum Analyzer

Another key feature of the R&S CMW platform is its integrated spectrum analyzer capabilities that can be used to determine if a Bluetooth device goes beyond three channels.

The analyzer shows the channels graphically, but each channel can be viewed on a table if preferred. The graphical representation of the channels also has overlays to show limits, giving engineers an understanding of how close their designs are to those limits. Individual channels that do go beyond those limits are highlighted.

 

Receiver/Transmitter Verification

The R&S CMW platform offers receiver/transmitter verification, including bit rate error, packet error, sensitivity measurements, and dirty transmitter tests. The bit rate error tests can be performed as individual measurements or as continuous measurements to see the overall error analysis.

The sensitivity measurements allow users to determine the sensitivity of a product by gradually reducing the output power until a define BER is reached. The dirty transmitter tests can be used to determine the resilience of the transmitter. The R&S CMW will produce poor-quality Bluetooth transmissions to see how well the product is able to decode the data stream.

 

One of the testers in the CMW platform, the CMW270. Image used courtesy of Rohde & Schwarz

 

Conclusion

For a product to be successful, it must be carefully developed with testing procedures to ensure conformity. While custom testing equipment can be used, equipment used in test houses, including R&S CMW is also a worthwhile option. 

The increasing use of IoT devices also means that the importance of Bluetooth will continue to grow. Therefore, a single device that can scan a spectrum, apply error tests, and detect if channel limits are breached might go a long way.