Enterasys ups high-speed wireless ante

  • John Cox (Computerworld)
  • 01 May, 2001 08:26

Enterasys Networks doesn't yet have a high-speed wireless LAN product. But it has something almost as good: a way to shift your firm from an 11M bit/sec wireless LAN to one almost five times faster.

Enterasys will announce a wireless LAN access point, the RoamAbout R2, which will let customers change an IEEE 802.11b wireless network into an 802.11a net, with a data rate of up to 54M bit/sec, by swapping a radio card. The 11a radios, which run in the 5-GHz band, compared with today's 2.4-GHz radios, are expected to appear in interface cards and access points from Enterasys and several other LAN vendors starting late this year.

Competitors such as 3Com, Cisco Systems, Agere Systems / Lucent Technologies and Symbol Technologies sell 802.11b 11M bit/sec wireless LANs now; all have announced plans, or are expected to do so, for 802.11a products.

An access point contains a radio transmitter that exchanges signals with other access points and with client devices, such as PCs or laptops, that have a corresponding wireless interface card.

Enterasys' R2 is designed as a foundation box that will eventually support an array of wireless products. Initially, net managers can buy the R2, then buy the 802.11b interface card and create an 11M bit/sec wireless LAN. Late this year, when the more powerful 11a products ship, net managers will have two options. One is to replace the slower radio card with the faster one.

The second is to pay for a daughtercard, slot it into the R2's PC Card slot, and run a 2.4-GHz and a 5-GHz radio. The two can run so close together because they operate in different bands and are based on different technologies. The slower radio can handle routine LAN traffic while the faster one handles such things as video or large image files.

The R2 can also function as a wireless bridge linked to antennae on building roofs to create line-of-sight connections that can network the wired or wireless LANs in one building with those in another.

Enterasys, a unit of Cabletron in Rochester, N.H., is billing the RoamAbout R2 as "802.11a-ready" because the box is designed for the higher-speed 11b interface cards.

"They're not really ready yet, because no one has any client cards [for 11a LANs]," says Jason Smolek, an International Data Corp. analyst. But Smolek likes the thinking embodied in the R2, which will let companies start with 11b and move selectively to 11a without scrapping the access points.

"The other [LAN] companies aren't thinking in terms of a migration to save customers money," Smolek says. "They sell their products at a premium: It will force enterprises to rip out 11b LANs and replace them with 11a."

But the migration is unlikely to be as simple as Enterasys executives suggest. First, higher-frequency radios have a shorter range than lower-frequency radios. Users may have to add 5-GHz access points to get the coverage they need. Secondly, for both radios, the wireless bandwidth is shared by the clients linking to given access points. Depending on the application mix and the client population shifts, net managers may have to move and add access points.

Smolek notes that 5-GHz radios are "power hogs," an especially critical issue for mobile laptop clients. Enterasys and other vendors should be planning power management features to help with this, he says.

With the faster 11a interfaces later this year, R2 also will support a battery of advanced services, according to Peter Beardmore, general manager for Enterasys' wireless products. These include:

- Wireless bandwidth provisioning, to allocate specified bandwidth to a given users or group of users.

- Quality-of-service features to give some types of traffic priority.

- Integrated Group Management Protocol support to limit such things as a video stream to specific users, rather than broadcasting it to all on the subnet.

- Advanced encryption to block hacking.

RoamAbout R2 will be launched at the NetWorld+Interop show in Las Vegas. The list price is $1,349, with one slot; the current 802.11b radio card is $149. The daughtercard, creating the second slot, is $149. Beardmore declines to say what pricing might be for the 5-GHz 802.11a radio interfaces when they're available.