Agilent Puts 802.11 to the Test
Among the compact collection of 802.11 equipment companies in CeBIT's Hall 13, Unstrung saw the Agilent test gear put through its paces, courtesy of RF and wireless application engineer, Spiro Moskov. The equipment and software can test any wireless chipset that operates at frequencies up to 6 GHz, and so covers the two current "flavors" of the Institute of Electrical and Electronics Engineers Inc. (IEEE)'s standardized wireless LAN technologies: 802.11a (54-Mbit/s over 5GHz), and 802.11b (11-Mbit/s over 2.4GHz), as well as the soon-to-be-ratified 802.11g (54-Mbit/s over 2.4GHz) (see 802.11g Approval Coming June).
The test suite comprises three pieces of hardware -- a signal generator, a signal analyzer, and a performance spectrum analyzer -- along with some software. With these, a vendor can test its products, whether transceivers or receivers, to ensure they meet standards specifications. The most important, and most complex, measurement is of error vector magnitude (EVM), says Moskov. This allows a vendor to identify sources of errors in the device being tested. And for each 802.11 technology there is a specific EVM limit that must be attained, so the vendor can check whether its product conforms to stringent IEEE specifications.
Moskov believes Agilent has stolen a march on its rivals, such as Rohde & Schwarz and Anritsu Corp.. "Rohde & Schwarz has a good signal generator, but not a complete solution for signal analysis. We believe we have a complete package that no one else has. We’re making easy business," says Moskov.
That business includes 802.11 silicon developers such as Broadcom Corp. (Nasdaq: BRCM) and Intersil Corp. (Nasdaq: ISIL).
Testimony to Agilent's abilities is the Wi-Fi Alliance's use of the vendor's Interoperability Certification Lab for testing products before it certifies them for the market (see 802.11 Security Issues Sorted?).
So what's next? The next generation of 802.11 testing equipment will be a low-cost tester for product functionality, designed to test, for example, PC cards and access points. At the moment, says Moskov, companies such as Proxim Corp. (Nasdaq: PROX) have only their existing products to use as a benchmark. "To test anything properly you need equipment that is better than the product you are manufacturing," says the Agilent man.
— Ray Le Maistre, European Editor, Unstrung