Another impressive feature of the Proxim Harmony architecture is that mobile clients can roam between access points on different subnets with all traffic tunneled through the APC. The Proxim Harmony APC can support as many as 10 different remote subnet entries. A Proxim Harmony access point supports two modes of operation: tunneled mode and managed mode. In tunneled mode, all access point traffic is routed through the APC, which processes all traffic, thus allowing policy management and subnet roaming. In managed mode, access points are still centrally managed, but they communicate directly with the wired network. While managed mode doesn't provide as much control over traffic, it avoids a potential performance bottleneck at the APC. If an APC becomes congested, you can scale the system by installing multiple APC, but that increases the cost. Proxim's challenge is to scale the APC's performance to handle as many access points as possible. Another key enterprise feature is the Proxim Harmony Power System, which provides power-over-Ethernet capabilities to 11a, 11b and OpenAir access points. SNMP support is also provided through the APC.
One feature we would have liked is the ability to adjust radio transmission power. This is scheduled to be incorporated in the next firmware release. Also, unlike Harmony's 11b and OpenAir access points, this version of the Harmony 11a cannot function in standalone mode without the APC. This issue is also expected to be addressed. Unlike Intermec's unit, Harmony lacks the capability to recover failed access points.
As for performance, Proxim's Harmony made a good showing. In the turbo mode, we obtained throughputs of more than 30 Mbps. Only SMC's product turned in higher numbers. Performance in standard 11a mode, which didn't vary much product to product, was average.
In transmission range, Proxim's Harmony access point is the best of any product tested. Its coverage extended as far as 140 feet in one direction. The ping coverage at the various spots indicated that up to 15 percent packet loss was observed at spot E, with up to 40 percent packet loss at spot F. At the remaining spots there was zero packet loss (see "Range Results" graphic).
Harmony 802.11a Access Point, $695. Proxim Corp., (800) 229-1630, (408) 731-2700. www.proxim.com or [email protected]