New switch wraps Wi-Fi in 802.11n blanket
- 25 March, 2008 15:01
Enterprise Wi-Fi vendor Extricom has launched an 802.11n switch, claiming its "blanket" Wi-Fi technology solves the power problem of the new standard, allowing a smooth transition to faster Wi-Fi.
"Other vendors' implementation plans for enterprise-class 802.11n abandon the 2.4GHz band, move to the 5GHz band, and require costly non-standard power-over-Ethernet schemes," said David Confalonieri, vice president of marketing at Extricom. Extricom's "blanket" architecture avoids all these problems, he said, and supports four radios in one access point (AP).
Although the draft 802.11n standard offers a substantial speed increase over today's Wi-Fi, most vendors have been unable to make a full implementation, using two radios and multiple antennas, which uses less electrical power than the maximum of 12.95 watts which can be provided using the power-over-Ethernet standard with which enterprises drive their APs.
Only Siemens has apparently solved the problem for a two radio access point, while other Wi-Fi vendors have offered different work-arounds including proprietary power-over-Ethernet, and tuning back the throughput of the access point.
Extricom can vault past that, because its blanket architecture - which puts all access points on the same radio channel - centralizes more of the processing. "Our AP has no CPU," said Confalonieri. "We can offer four radios and use less than 6 watts." Extricom's four-radio N access point is a new version of quad-radio 802.11abg APs launched a year ago.
Despite this, Extricom suggests companies should introduce N in stages, especially in the 5GHz band which has rarely been used for Wi-Fi till now, and whose propagation differs from the normal 2.4GHz band. Extricom says its systems can provide full N coverage and support legacy 802.11b and 802.11g using only the 2.4GHz band, because every access point uses the same channels - in contrast to "cell-planning" systems from Cisco Aruba and Trapeze, where adjacent APs have to use different channels.
This leaves the 5GHz band empty for gradual deployment. "You can introduce a slow roll-out of N, without changing the real estate, until your business has clients which require 5GHz N," said Confalonieri.
"The 802.11n standard promises to play a pivotal role in finally making the all-wireless enterprise a reality," said Stan Schatt, director of wireless connectivity at ABI Research.
"The implementation of 802.11n should be about evolution, not revolution," said Gideon Rottem, chief executive of Extricom, who has said cell-planning is the 'original sin' of Wi-Fi.
The EXRP-40En four radio access point includes two n/a/b/g radios and two a/b/g radios, which can be operated in any combination of channels and bands. The 'n' equipped radios support 3x3 MIMO (multiple-in, multiple-out) antenna configuration. Extricom has also launched a tri-radio AP, with two 'n' radios and one a/b/g radio.
A firmware upgrade can give existing Extricom switches the ability to support the new APs, and a new switch, the EXSW-1600 has been announced, along with an antenna bar, which can add more antennas so one AP can have up to twelve antennas on a wall-mounted bar, connected to the AP by a single cable.