WLAN Gets Dense
Introducing the concept of a wireless LAN switch, or controller, to secure and manage larger networks of access points was really just the first part of the puzzle.
Now -- as corporate customers slowly start to get more comfortable with the concept of installing 50 or more 802.11 radios on a campus -- the firms that want to provide the kit are trying to address the problems of providing capacity, among APs in a really crowded RF environment.
Aruba Wireless Networks laid out its solution to the density issue this week with new "grid" software and mini APs intended to provide high-capacity wireless coverage to a few users rather than the 10 or more served by most of the corporate installations today (see Aruba Grids Up).
Rivals have questioned how effective this approach will be.
"By introducing more APs at a lower power into the network, Aruba appears to be forcing wireless LAN clients to go through the handoff/reauthentication routine more often than before," says Joel Vincent, senior product marketing manager at Meru Networks Inc. Meru has developed its own "zero handoff" architecture that treats an AP network as if it were all one AP (see Meru Grabs $17M).
Aruba counters that because its system holds user information at the switch, and facilitates centralized changeovers using mobile IP and a DHCP proxy, its new APs will still handoff faster than standard APs.
"It's handled faster at the switch than it is at an AP," claims Aruba's director of communications, David Callisch.
Meanwhile, rival Airespace Inc. says that it is also examining a micro-cell architecture not unlike the one Aruba has announced for dense deployments. But Jeff Aaron, senior marketing manager at Airespace, questions Aruba's concept of putting the access point in the wall and not the ceiling.
"You absolutely need to install an AP in an area that has clear visibility of the network... Something like a WiFi walljack is not recommended." He questions how Aruba's ground-level system will be able to react to changes in RF environment around it -- if, for instance, a user moves a box in his cubicle.
Aruba says its new APs will still be able to detect other nearby APs, and the system software will adjust overall radio power and channel settings to suit the environment. But the AP itself will be able to do "local" updates -- like adjusting to changes in a user's cubicle -- and relay details of those changes back to the system.
On the radio front, Airespace recently introduced its own "smart antenna" access point, in part to try to address capacity issues for larger deployments.
In fact, the need to introduce better radio technology like the 802.11n radio standard (108-Mbit/s plus) that is currently on the drawing board is the one thing all three startups agree on. Both Aruba and Meru say they are looking at introducing faster access points.
— Dan Jones, Site Editor, Unstrung