Wi-Fi to fill mobile WAN gaps

As AT&T prepares yet again to upgrade its HSPA 7.2 3G access and backhaul networks in the United States, the word is that some mobile network operators will eventually look to offload some of their spiraling mobile data traffic onto Wi-Fi networks. It's not clear just yet exactly what kind of experience such a move would deliver to users, but it makes sense for major operators with both types of networks to supplement their mobile WANs with Wi-Fi where they need the bandwidth.

That seems particularly relevant for AT&T, which is currently the sole distributor of the Apple iPhone in the United States, a device that is at least perceived to place unprecedented and unanticipated loads on the carrier's network. Even so, however, a recent Gartner study did indicate that all four major U.S. carriers' 3G networks have failed to deliver on customer throughput expectations.

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In fact, enabling access to AT&T's Wi-Fi networks, which comprises 20,000 hotspots across 50 states, is a stated component of the carrier's latest upgrade initiative. It aims to allow customers to use the "best available" AT&T mobile broadband connection wherever they happen to be, according to the company.

Carriers who want to shift traffic on and off Wi-Fi networks to provide better throughput will need to figure out some way to make that a seamless user experience.

For example, users with a universal client connectivity application, from companies such as service aggregator iPass, can "transfer" from a 3G mobile data network to a Wi-Fi network fairly easily, but the process does require a few user clicks. Ultimately, what would be desirable would be for the underlying provider to place user traffic and sessions on the "best" wireless network available at the time without the user having to fuss about it or worry about rate changes.

Joanie Wexler is an independent networking technology writer/editor in Silicon Valley.