With iPhone, Wi-Fi Use Grows on AT&T Networks

[qi:gigaom_icon_routers] Following up on my previous post, “How Smartphones Are Making Wi-Fi Hot Again,” I’ve heard from different network providers that have shared their data with me. Today, folks from AT&T (s T) let us know that the traffic on their Wi-Fi network is going up pretty sharply.

During the second quarter of 2009, AT&T handled nearly 15 million Wi-Fi connections — a 41 percent increase over the first quarter. Nearly 25.6 million connections have been made so far in 2009 vs. 20 million seen in all of 2008.

AT&T acquired Wayport for $275 million last year to alleviate the concerns of iPhone owners. Wayport provides Wi-Fi service in Starbucks and airports, among other locations. iPhone (s aapl) and other smartphone consumers are using this network quite aggressively.

During the second quarter of 2009, 49 percent of connections to AT&T’s Wi-Fi network were made with smartphones, including the iPhone, up from 38 percent of connections in the first quarter, the company said.

The data from AT&T and Meraki shows there is a significant shift toward Wi-Fi enabled devices. The interesting thing to note is that the spike in traffic followed the availability of auto-authentication for iPhone OS 3.0 users, which launched in June. Comparing the month of May vs. June, iPhone connections at AT&T Wi-Fi hot spots more than tripled.

As you may have noticed, I am tracking these developments pretty closely, and I’m also looking at usage on 3G networks. (If you want to share data or insights, drop me an email or DM me on Twitter.) One of the reasons I’m interested in all these stats is that I want to figure out not only the impact on the networks (including backhaul) but also understand what this kind of connectivity means for apps.