Global Sources
EE Times-India
Stay in touch with EE Times India
EE Times-India > Networks

Testing WiMAX, testing

Posted: 12 Nov 2008     Print Version  Bookmark and Share

Keywords:WiMAX  WiMAX Wave 2  WiMAX testing  broadband wireless access 

Time and cost constraints

While any testing solution must be accurate enough to ensure that WiMAX signals meet these more stringent specifications, "testing has to meet time and cost constraints that differ little from those of Wi-Fi," Lukez said. "It's a case, again, of having to do more—more accuracy, more complex testing—without taking significantly longer or costing significantly more."

WiMAX Forum defines and conducts conformance and interoperability testing to ensure that different vendor systems work seamlessly with one another. Successful testing gives the tested device a "WiMAX Forum Certified" designation. "The Forum goes to great lengths to warn vendors that claims like 'WiMAX-like' and 'WiMAX-compliant' are not WiMAX Forum Certified, which means their equipment isn't interoperable with other vendors' equipment," said Ron Resnick, president of WiMax Forum.

WiMAX certification is crucial for the market to grow—without it, interoperability would be limited. "Interoperability is like any other standard," said Edwin Lowery, principal consultant for Verigy's Wireless Centre of Expertise. "If everyone went [his or her] own way, you wouldn't be able to use your Compaq computer with the Sprint network, or use your Sprint handset in Europe, etc. Compliance allows for interoperability. As an example, imagine if there were 10 different Bluetooth flavours. You could 'buy a Bluetooth,' but the device only works with this one compliant headset. What's the point of a standard if it only works with one product?"

"There is really only one solution: Make sure WiMAX devices are tested in production in ways that ensure they truly meet the standard's specifications," said Rob Brownstein, LitePoint vice president, market relations and communications. "This sounds simplistic but it's not. In development, one has some latitude with test time. In production, where pricing and margins can make or break a market, trading off testing comprehensiveness for time and cost is very tempting. The solution is not to give in to temptation."

Verigy's Lowery explained specific challenges of WiMAX testing: "WiMAX supports multiple modulation types and multiple modulation bandwidths. To effectively test WiMAX, you need a mechanism to easily and effectively create the multiple waveforms used to test the device under test—that has to be part of the test strategy."

Lowery said that older 2G testers may not have the performance, phase noise and linearity required to test WiMAX to spec. The newer testers have the capability to perform the challenging EVM tests. "It is important to have good synchronisation, good I/Q balance for your RF sources and I/Q balance between the AWGs [arbitrary waveform generators] and digitisers," said Lowery.

 First Page Previous Page 1 • 2 • 3 Next Page Last Page

Comment on "Testing WiMAX, testing"
*  You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.


Go to top             Connect on Facebook      Follow us on Twitter      Follow us on Orkut

Back to Top