The ins and outs of WAN mobility

Last time, I indicated that 2.5/3G network deployments have hit some snags and their fate hangs in the balance. The biggest obstacles are the relatively low speeds supported by 3G and the lengthy deployment paths required of the carriers for achieving ubiquitous 3G coverage, compared to emerging technology competitors.

In addition to wireless LANs, contenders for WAN mobility include networks based on emerging 802.16e and 802.20 air interface standards. Let’s take a look at how the three stack up based on a few different variables:

* 802.16e

Speed: Shared data rates of about 70M bit/sec. Expected to be apportioned to customers in symmetric bandwidth increments similar to T-1 (1.5) speeds.

Application:  Aimed at fixed wireless last-mile users with adjunct mobility via PC Card technology. Services will likely fall in “metro” (regional or local) areas and consist of low-latency data and real-time voice services.

Estimated standard completion: Year-end.

* 802.20 (a.k.a. mobile broadband wireless access or “MBWA”)

Speed: Per-user symmetric data rates of about 1M bit/sec at vehicular speeds of 150 miles or 250 kilometers per hour.

Application: Aimed initially at delivering low-latency IP data services to fully mobile users via PC Card-enabled data devices, for global mobility and roaming. Voice-over-IP to be supported as well.

Estimated standard completion: Unknown.

* 3G (a.k.a. IMT-2000)

Speed: 2M bit/sec in fixed or in-building environments; 384K bit/sec in urban environments, 144K bit/sec in mobile WAN environments

Application: Cellular voice with some asymmetric data service support for global mobility and roaming.

Estimated standard completion: Five different standards complete; in various stages of rollout and interoperability