Bluetooth Product Qualification

When counting the contributions to the electronics industry, Bluetooth is a big player. In 2005, more than 200 million units shipped with Bluetooth technology aboard, and market forecasts predict the billion units mark by 2010.

With chip volumes up and prices down, Bluetooth is being added to a wide array of consumer electronics products. But before a product can carry the Bluetooth logo, it must undergo a very exacting qualification process and be registered with the Bluetooth Special Interest Group (BT SIG).

Product Qualification
Bluetooth technology is defined by the BT SIG. Formed of eight promoter companies and hundreds of associate and adopter-level member companies, the BT SIG, through its various committees and working groups, creates the specifications that define Bluetooth protocols. Bluetooth intellectual property may be used in products royalty-free as long as those products pass a series of functional and interoperability tests called product qualification and the product is listed on the BT SIG qualification website.¹

Any company that manufactures a Bluetooth product can become a BT SIG member and qualify that product. Adopter-level membership in the BT SIG is free. Associate members pay a fee based on the annual revenue of the company. Currently, companies with annual revenue of less than $100 million are charged an annual membership fee of $7,500. Those with higher revenues pay $35,000 per year.

Adopter-level members may use published BT intellectual property but are not allowed early access to specifications in development or participation in the working groups that create the specifications. Associate members enjoy early access to specifications, the capability to influence the technology by participating in specification working groups, reduced fees, and other benefits.

All members pay a fee per qualified design. Adopter-level members are charged $10,000 and associate members $4,000 if the new PRD 2.0 process is used or $5,000 if the PRD 1.0 qualification process is applied. Given the difference in qualification costs, companies should look at their qualification plans to determine if an associate membership will actually save money by paying a lower qualification fee.

The Qualification Process
Qualification involves four basic steps. First, a test plan is developed identifying the features that require testing and the tests for those features. Second, the testing is performed, and test reports are generated. Third, the test reports are submitted to the SIG, and fourth, the qualified product is listed on the SIG website.

The BT SIG currently is re-engineering the product qualification process. A new version of the Qualification Program Reference Document has been written, but the BT SIG still is operating under PRD 1.0 with a date for the PRD 2.0 rollout pending.

Step 1. Obtain a Design ID
Product qualification begins when a manufacturer visits the BT SIG website² and pays a fee of $1,000 that will be applied to the final qualification fee. The BT SIG then assigns a design ID to the project.

Multiple related products may be listed under one design ID with no further fees required. For example, if a cellular phone maker uses the same Bluetooth hardware and software design in all members of a product family, only one design ID is required.

Step 2. Develop a Test Plan
All elements of a Bluetooth-enabled device must be tested and qualified, but not all of this testing must be done by the product manufacturer. For example, the product may contain a commercially available protocol stack that has been prequalified as a component by the stack vendor. Any product that uses such a stack need only reference the qualification record of the stack vendor.

For the features of a product that require testing by the manufacturer, a test plan is developed. To simplify preparation for product testing, the BT SIG has provided an online tool, the Test Plan Generator (TPG), to automate the process of identifying qualification tests that must be run for a particular product.

The manufacturer identifies the features of the product using the Profile Implementation Conformance Statements (PICS). The PICS designate all available features for a particular profile or specification part along with an indication of mandatory or optional for each feature. As a matter of convenience, the manufacturer should complete these forms using the SIG-supplied PDF files before moving to the online tool.

PICS data is entered into the TPG, which produces a list of tests that must be run against the product.

Step 3. Testing
The methods used for testing a product depend on what is being tested. Low-level testing of radio features will require some rather costly equipment to capture and analyze device performance. If this sort of testing is necessary, it often is more cost-effective to have it performed by a third-party laboratory that specializes in such work.

Bluetooth sniffers used to capture the over-the-air protocol exchanges between two devices are somewhat affordable. They generally cost between $8,000 and $15,000 plus an annual maintenance fee that covers the necessary software upgrades. On the other hand, more sophisticated analysis tools that can directly run the qualification code developed by the BT SIG, depending on options and capabilities selected, can exceed $500,000.

Profile-level tests can be as simple as connecting a hands-free car kit to a Bluetooth cell phone, initiating a phone call from the car kit, and verifying that the call was properly established. Profile testing also may require the use of a Bluetooth sniffer to capture the over-the-air protocol for analysis.

Each Bluetooth profile has an associated test specification that describes the procedures as well as pass and fail criteria. The test plan generated in Step 2 determines which of these tests must be run to achieve qualification.

After completing the testing, a report is generated. This report describes the test setup, the test equipment used, specific information about the device being tested, the tests executed, and the results for these tests. A more detailed description of the test report is given in PRD 2.0.

Step 4. Listing the Product
Following the completion of all required test reports, the manufacturer completes and signs a Declaration of Compliance that states the BT specifications implemented by this design. It is the responsibility of the manufacturer to review all documentation and test results to ensure compliance with the BT specifications. The product�s qualification may be revoked if nonconformances are found in the product.

Also required is a signed Supplier Declaration of Conformity (SDoC). This document attests that all requirements related to the PRD 2.0 process document have been fulfilled. The SDoC also grants the BT SIG or its agent permission to audit the qualification submissions made for this product as specified in the Qualification Surveillance, Auditing, and Enforcement Process (QEP) document.

Last in this process is creating a Qualified Design Listing (QDL) on the BT SIG website and paying all fees due. Remember that more than one product may reference the same QDL if they use the same BT subsystem hardware and software. There is no fee to list products based on a valid QDL.

The qualified design ID issued by the BT SIG must be published and easily located on the product, its documentation, or its packaging. There should be no need to disassemble a Bluetooth product to locate its design ID.

Product Qualification Resources
If all of this is beginning to sound a bit intimidating, help is available. There are full-service vendors who can assist with all aspects of product qualification and perform the testing using BT SIG-approved equipment.

If a manufacturer already owns sufficient test gear as a result of the product development cycle, a Bluetooth Qualification Expert (BQE) may be the solution. BQEs are required to maintain current knowledge of the qualification process and participate in qualification-related SIG activities such as test events, process meetings, and the testing committee.

A BQE may be contracted to review and submit qualification documents on behalf of a client. In addition to the expert guidance, such a submission will not be subject to a random audit by the BT SIG.

Enforcing the Process
The qualification process includes a new quality enforcement mechanism described in the QEP document. Several mechanisms exist for detecting nonconforming products:

� Complaints submitted to the SIG website. If your product experiences difficulties interoperating with an off-the-shelf BT product and you can determine that the fault is a nonconformance in the other product, there is a mechanism to report that problem to the SIG.
� SIG testing of products purchased on the open market.
� SIG random audits of submitted designs.
� SIG for-cause audits of submitted designs triggered by nontrivial abnormalities in the submitted qualification documents; for example, required testing that is missing.

When a conformance issue is discovered, the SIG will work with the product manufacturer to resolve the issue. Members always will be given the opportunity to correct a problem.

A Corrective Action Plan (CAP) is drafted and agreed to by the manufacturer and the SIG. The manufacturer must complete the plan within the agreed time line. If this is not done, the SIG can revoke the qualification of the product, which means the product may not be sold with the Bluetooth logo and may violate the intellectual property licenses granted to qualified BT products.

Profile Tuning Suite
To assist in product testing, the Profile Tuning Suite (PTS) software application is being developed and may be used to perform much of the PRD 2.0 required testing. In the future, the use of the PTS for testing could become mandatory. The exact rules governing the use of PTS will depend on the profiles that it supports at any given time.

PTS is an application hosted on a Windows XP system and uses a USB BT dongle for communications with the target device or implementation under test (IUT) to use the BT term.

The PTS tool provides a graphical user interface and allows the tester to build a project that can be configured to the test requirements of a particular IUT. Information about the IUT, such as device address and supported features, is entered in a format similar to the Implementation Conformance Statement and the Implementation eXtra Information for Testing document that have long been used by the BT test process.

Profile-specific test sets are based on the features of the IUT. Running a test is as simple as double-clicking the icon for the desired test. The PTS automates as much of the test as possible. But certain activities, such as passkey entry for Bluetooth security, require user actions on the IUT that cannot be automated by the test software.

The PTS uses the SIG-developed Tree and Tabular Combined Notation (TTCN) test definitions to drive test execution.

The PTS provides several useful features to complement the execution of qualification tests. First, an automatic report generator creates a test report with the click of a mouse. This report may be used to document compliance with profile specification requirements.

Second, the PTS supplies a detailed trace of messaging traffic that can be used as a debugging tool if problems are encountered. Third, a Message Sequence Chart (MSC) is produced, also useful for documenting device operation and debugging.

The PTS system is under development at this time, and the current version is available to all SIG members as a download from the SIG website. For associate and promoter members, the PTS tool is free while adopter members will pay $7,500. Support is available for an additional fee as well as a development kit that will allow you to add tests to the PTS.

Summary
To help you get started, here are some suggestions for qualifying your Bluetooth-enabled product.

� Start planning for qualification from the beginning of your project. Some design decisions may be influenced by knowing in advance what testing must be done later. Selection of test equipment should be made with an eye toward what will be useful later in product qualification.
� Become a SIG member. Look carefully at your Bluetooth plans before immediately opting for the free adopter membership. Paying a fee for joining the SIG at the associate level will save money later in the form of reduced fees for qualification and the PTS. In addition, your company will have early access to specifications and be able to participate in the development of those specifications. These benefits may far exceed the cost of the upgraded membership.
� Seek expert help especially if you are new to Bluetooth product development. It may be more cost-effective to have an outside firm do your qualification testing. Using a BQE when preparing the qualification submission may prevent errors that will be costly to correct later if your product does not comply with the BT specifications or qualification process.
� Perform interoperability testing with as many products from as many manufacturers as possible. Qualification testing can only go so far in proving interoperability between products, and specifications cannot anticipate every possible method of implementing a feature. Be certain that your product is as robust as you can make it.
� Don�t shortcut testing. Remember, the SIG and your competitors are able to challenge your claims of specification compliance.
� Always refer to the current specification to ensure compliance to the qualification process.

The purpose of the qualification process is to ensure that products bearing the Bluetooth logo adhere to the Bluetooth specifications and will interoperate with similarly featured products from other manufacturers. In short, the objective is to provide an excellent user experience. Isn�t that what you want from the products that you purchase?

References
1. http://qualweb.bluetooth.org
2. https://programs.bluetooth.org/tpg/

About the Author
Burch Seymour, a principle engineer with the automotive communications and electronics group of Motorola, has nearly three decades of experience in software engineering. Mr. Seymour received a B.S. in applied math and computer science from Washington University. He currently is a member of the Bluetooth Car Working Group, which addresses vehicle-related BT profile development. Motorola, 21440 W. Lake Cook Rd., Deer Park, IL 60103, 847-862-2592, e-mail: [email protected]

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June 2006