As enterprise WLANs expand to deliver coverage and support for business-critical applications, network and RF management have grown increasingly important—and complex. Reliability and stability while operating in unlicensed spectrum is now the second biggest challenge facing large-scale WLAN deployment, according to this year’s WLAN State of the Market survey.
WLAN controllers automate tasks like channel assignment, power tuning, and load balancing, while WLAN monitoring systems (embedded or overlay) offer insight into operational and performance problems. However, both focus on 802.11—for example, avoiding co-channel interference between APs, or detecting excessive 802.11 frame retransmissions. In unlicensed airspace, this can result in missing the forest for the trees.
“Wireless spectrum is a strategic asset for our customers, and its management is key to the robust delivery of mobility applications,” said Brett Galloway, vice president and general manager of Cisco’s Wireless Networking Business Unit. Acquiring Cognio, the market leader in RF spectrum analysis, will help Cisco deliver rich and dependable end-user mobility experiences, said Galloway.
Expanding wireless horizons
Last week, Cisco announced an agreement to purchase Cognio. The acquisition—number 122 for Cisco—is expected to close in the first quarter of 2008. Cognio will become part of Cisco’s Wireless Networking Business Unit, under the Ethernet and Wireless Technology Group.
“With a strong product and technology portfolio and consistent innovation from a talented group of engineers, Cognio has emerged as the leader in spectrum intelligence technology,” said Galloway.
Cognio’s expertise will complement Cisco’s own broad networking expertise, as well as 802.11 technology acquired from other sources—notably Airespace. According to Cisco, “This acquisition will expedite the delivery of industry-changing capabilities and is consistent with how Cisco uses business development strategies to move into new markets or to gain new technologies.
Drilling into RF interference
Cognio’s Spectrum Expert products are designed to find and solve RF interference problems that frequently inhibit proper operation and optimal performance of business critical wireless deployments.
Spectrum Expert analyzes, diagnoses, and locates radio devices that happen to be operating in or near an enterprise network. It does so by listening to physical layer transmissions in the frequency ranges used by Wi-Fi (2.4GHz–2.5GHz, 4.9GHz–5.9GHz) and RFID (851MHz–870MHz, 902MHz–960MHz). By detecting, classifying, identifying, fingerprinting, and finding non-Wi-Fi/RFID sources of interference, Spectrum Expert can isolate problems in the RF spectrum from problems in the wireless network, eliminating guesswork about what’s actually causing trouble and how to best mitigate it.
For example, Spectrum Expert for Wi-Fi combines a spectrum analysis PC card with Windows Vista/XP/2000 software. With the help of an internal or external antenna, the card sweeps designated frequencies, capturing detected RF energy. Those observations are analyzed by expert software, matched against RF signatures for common device types, including 802.11a/b/g/n, Bluetooth, DECT/TDD/analog cordless phones, NTSC/PAL/SECAM analog video cameras, and microwave ovens. Transmissions are correlated to individual source devices. A “finder” can then be used to home in on a given device and narrow down its physical location.
Putting RF intelligence to work
According to a statement from Cisco, “The acquisition will provide Cisco with complementary and differentiating technology, intellectual property, and a core team to expand Cisco’s leadership in unified wireless networking.”
However, in addition to selling Spectrum Expert directly to about 1,000 customers, Cognio now partners with AirMagnet, Fluke Networks, and WildPackets. Each of these vendors currently sells a privately-branded OEM version of Spectrum Expert to their own customers. Cisco reportedly does not intend to end these OEM partnerships.
So where will differentiation come from? Cisco has been reselling Spectrum Expert for the past year or so. Cognio is already capable of forwarding Spectrum Expert alerts to the shipping version of Cisco’s Wireless Control System (WLC). Next month, WCS Version 4.2 will include integrated graphics that make it easier for a WLAN manager drill down and view RF interference sources. Tighter integration will no doubt occur in the future, as Cisco attempts to leverage RF spectrum analysis throughout its Unified Wireless Network initiative.
