Broadband wireless access (BWA) has become the best way to meet escalating business demand for rapid Internet connection and integrated data, voice and video services. BWA can extend fiber optic networks and provide more capacity than cable networks or digital subscriber lines (DSL). One of the most compelling aspects of BWA technology is that networks can be created in just weeks by deploying a small number of base stations on buildings or poles to create high-capacity wireless access systems.
BWA has had limited reach so far, in part because of the unmet need for a universal standard. While providing such a standard is important for developed countries, it is even more important for the developing world where wired infrastructures are limited. (Multimedia Solution, 2004) Excerpted from Wimax Forum (2005) The test process includes the development of test scripts, lab preparation, and validation Of the test scripts and certification testing, as described in more detail below:
Development of Test Scripts for Validation The first step in the process is the development of test scripts, which describe individual tests to be performed on the vendor’s product to ensure it meets the mandatory functionality requirements for certification. The test scripts were jointly developed by ETSI (European Telecommunications Standards Institute) and the WiMAX Forum in May of 2005. The features to be tested are based on IEEE 802. 16- 2004 and ETSI HyperMAN specifications.
Lab Preparation The lab preparation process involves validating test scripts, sourcing relevant test tools, opening the lab, preparing test hardware, integrating test scripts into the test hardware and finally, accepting vendor equipment. Validation testing of Test Scripts and Test Bed Validation of the test scripts is a necessary process in the certification program. Before a test script is released for use in the lab (test bed), it must be tested with a minimum of three (3) vendor products for a given profile.
A profile describes a set of operational parameters over which the equipment operates including frequency band, duplexing scheme (TDD or FDD), channel size, etc. Currently, the WiMAX Forum has selected two (2) specific profiles, described below, with additional profiles planned for 2006. If all three vendors successfully pass validation testing, then the script is considered valid. Certification testing the final step in the test process is certification testing, which involves two key components: conformance and interoperability testing:
Conformance testing. Test activity to verify a vendors implementation of the standard is compliant to a set of 802. 16-2004/HyperMAN specifications selected by the WiMAX Forum. Interoperability testing. Testing activity to verify a vendors subscriber unit is able to establish a link and communicate with two other vendors’ base stations, or vendors base station is able to establish a link and communicate with two other vendors subscriber units.
Certification testing will be performed in multiple releases and waves. Multiple releases are necessary to test products as they evolve over time with new features/specifications. For each release, the procedure will test all new features as well as all previously tested features. Note that each release will be backward compatible with the previous release (e. g. Release 2 products will operate with Release 1 products and support all Release 1 features).
For each release, there will also be The first two system profiles to be certified are FDD systems in the 3. 5 GHz band with a 2×3. 5 MHz channel bandwidth and TDD systems in the 3. 5 GHz band with 3. 5 and 7 MHz channel bandwidth. In the first half of 2006, we expect to certify products in the 5. 8 GHz band. The certification testing like in many other technologies is an evolving process. As test scripts are developed and validated, the WiMAX Forum will continue to add testing capabilities into the certification test bed.
In order to do this in an efficient manner, testing capabilities are introduced in individual releases (as discussed above) to allow vendors to incorporate firmware and software changes that support required testing capabilities of the test bed. During the first two certification releases network entry, dynamic services and bandwidth allocation functionality is tested along with interoperability for these capabilities. In subsequent releases we will test additional features such as QoS, ARQ, AES, etc.
Vendors are actively involved in the identification of testing requirements for each release of certification and thereby will plan to upgrade equipment via software and firmware releases. Products that are tested to a later certification release must be backwards compatible to earlier released certified products. Since WiMAX Forum certified products are tested for interoperability and are backward compatible; you have the option of purchasing newly released products from other vendors with the assurance that it will support the release 1 products you already deployed in your network.