Wimax standards and Security The Wimax

Interoperability and Certification Testing

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   WiMAX Certification Overview
   

One of the key elements of WiMAX technology is the interoperability of WiMAX equipment certified by the WiMAX Forum. Without a certification program, it would be very difficult to ensure that the equipment interoperate without going through independent testing. In any standards-based technol- ogy, equipment vendors try their best to develop products that comply with the standard. However, different interpretations of standards can lead to lack of interoperability among their products [4].
The WiMAX certification program, launched by WiMAX Forum, is designed to address the conformance and interoperability issues by encour- aging cooperation among vendors through “Plugfest’’ events, where they can informally verify interoperability, and through the formal and official certi- fication testing. The certification program was launched in mid-2005. The certification process includes the following two types of tests that focus on the physical (PHY) and medium access control (MAC) layers:

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  Conformance testing to ensure that products correctly implement the specifications defined by IEEE 802.16 and ETSI HiperMAN stan- dards. The vendor is required to complete the PICS questionnaire to specify which features have been implemented in the product for conformance testing. Based on the results of conformance
  

testing, the vendors may choose to modify their hardware or firmware and formally resubmit their products for conformance testing.

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  Interoperability testing to verify that the products from different vendors work correctly within the same network. At least three vendors have to submit products within the same certification pro- file (defined by RF spectrum band, channelization, and duplexing mode used) to start interoperability testing.
  

The certification testing is conducted at independent labs recommended by the WiMAX Forum. CETECOM lab in Spain was the first lab to per- form certification testing, while recently, the Telecommunications Technology Association (TTA) in South Korea was added as the second certification lab. The WiMAX Forum plans to announce additional labs in the future [4]. After a successful certification testing, vendors receive a WiMAX Forum certificate and a test report.

The WiMAX certification process is summarized in Figure 9.1. The roles for the main players in the certification program are summarized in Table 9.1.
It is to be noted that not all WiMAX products will (or are expected to) inter- operate with each other. For example, a subscriber unit operating at 3.5 GHz band will not be able to establish a connection with a 5.8 GHz BS; nevertheless, both products are based on the same standards (IEEE 802.16 and ETSI Hiper- MAN) and meet the same requirements. The WiMAX Forum has defined the following two types of profiles to address the need of different classes of the products that use the same technology: system profiles and certifica- tion profiles. Working with profiles make interoperability more effective and focused.

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