Robert Graham
The introduction of new conformance tests is the first step in improving Bluetooth interoperability. A more effective test environment is still needed.

 

Up until January 1, 2003, manufacturers of Bluetooth devices had been able to use engineering evidence and a declaration (Category B testing) to satisfy a Bluetooth Qualification Body (BQB) that their Bluetooth solution had passed the radio-frequency (RF) and the protocol and profile conformance tests.

As of February 2003, Category A testing became active for all RF conformance test cases (except for out-of-band spurious emissions). In addition, beginning April 1, more test cases became active. These include baseband, link manager, service discovery protocol, and generic access profile tests. Test cases for the logical link control and adaptation protocol (L2CAP) and the sequenced packet protocol (SPP) and RF communications (RFCOMM) layers are also expected to be activated at a Category A level in the future.

Category A Testing

Category A testing is defined as mandatory testing performed at an accredited Bluetooth Qualification Test Facility (BQTF) using a validated test system. Existing Bluetooth wireless solutions that are listed before January 1, 2003, do not need to be retested under the new regime.

However, the new testing requirements present significant
implications for Bluetooth products listed after January 1, 2003.

New Bluetooth products will almost certainly require some test cases to be performed at a BQTF using validated test systems. In addition, new Bluetooth end products incorporating pretested components listed before January 1, 2003, may still require some test cases to be performed at a BQTF using validated test systems. In every case, it is imperative to contact the intended product-listing BQB. The BQB will take into account all variables when deciding testing requirements.

Many manufacturers have expressed concern at the cost implications of this new regime for their products . There will undoubtedly be additional test time required and, therefore, more costs payable to a BQTF. However, this increased cost should be offset by the fact that a manufacturer no longer needs to produce a test report containing detailed engineering evidence for tests that now fall under Category A. In addition, the time it takes for a BQB to assess a BQTF test report will be dramatically reduced when compared with the time required to wade through a test report for Category B test cases.

Accredited Testing

The idea of accrediting test labs that use validated test equipment for Bluetooth testing is not new. The concept was introduced in the first official Bluetooth Qualification Program Reference Document drafted by the Bluetooth Qualification Review Board (BQRB) for general release in December 1999. The idea then was to standardize the testing to provide a consistent test procedure applicable to all Bluetooth products.

The desired effect is to aid interoperability by normalizing the qualification test requirements of the fundamental layers of the Bluetooth protocol stack. This has been a costly process both for the BQRB (in commissioning tree and tabular combined notation [TTCN] test cases for protocol/profile conformance testing) and for the test equipment manufacturers (in developing test platforms).

Pretested Components

To reduce the development cycle of Bluetooth products and to minimize test requirements, manufacturers should consider using pretested components. These Bluetooth building blocks are readily available and can be found by searching the Qualified Products List on the official Bluetooth Web site (http://www.bluetooth.org).

Pretested and qualified components have already been through the qualification process to prove that it is possible to qualify a Bluetooth product using the component. It is important to note, however, that the use of a pretested component does not mean automatic qualification of a product that incorporates it. Retest requirements are decided by a BQB.

It is also critical to remember that regulatory testing of Bluetooth devices is required in order to sell them. Such testing may involve radio approval, and meeting electromagnetic compatibility, safety, and specific absorption rate requirements, depending upon the country or region where the product is to be sold.

Conclusion

The introduction of Category A testing should benefit all organizations with interests in Bluetooth. The standardization of the testing is an initial step to end interoperability problems. The final step will be the introduction of an effective profile interoperability test environment.

Robert Graham is a Bluetooth Qualification Body and is principal engineer for Radio Frequency Investigation Ltd. (Thatcham, Berkshire, UK). He can be reached via e-mail at robert.graham@rfi-wireless.com.

Bluetooth: New Specification Uses Adaptive Frequency Hopping   The new Bluetooth 1.2 specification includes changes designed to provide improved coexistence with other wireless technologies such as 802.11 (Wi-Fi). The new specification also provides better voice quality and faster connection time, according to Anders Edlund, marketing director of Bluetooth SIG. With adaptive frequency hopping, the new specification avoids busy frequencies, Edlund noted in the April 2003 edition of Ericsson's Bluetooth Moves. He said frequency hopping would eliminate the noise caused by collisions with technologies such as 802.11, improving both sound and data quality. In addition to improving the quality of the Bluetooth specification, Edlund said the use of adaptive hopping provides a good example of how to cooperate with neighboring technologies in the unlicensed band. The new specification is designed to be completely backward compatible with the earlier 1.1 version. The 1.2 specification also includes advancements to the synchronous connection-oriented (SCO) link to improve voice quality. The new specification provides more efficient bandwidth management. Edlund said the new 1.2 version can use multiple, simultaneous Bluetooth connections using Scatternet (the ability to make a call using a headset while at the same time synchronizing data between a mobile phone and a PC, for example). The new specification is unlikely to result in new types of devices, but Edlund said he foresees improved products within current Bluetooth applications.