AT&T Inc. (NYSE: T) is reportedly planning to let Wi-Fi take the strain off its 3G networks in 20 New York parks with a major extension of its mobile data off-load program in the Big Apple this year.

The Wall Street Journal reports that AT&T CEO Randall Stephenson will get together with Mayor Michael Bloomberg at Thomas Jefferson Park to reveal details of the Wi-Fi plan.

AT&T has already deployed Wi-Fi "hotzones" in Times Square, The Rockefeller Center and areas in Charlotte, N.C., Chicago and San Francisco. The deployments, which use mesh technology to extend the range of the wireless LAN signal, are intended to speed up mobile data downloads and off-load traffic from AT&T's 3G cellular network onto Wi-Fi.

The operator uses equipment from BelAir Networks Inc. and others in its deployments, according to the Journal. The system works by co-locating carrier Wi-Fi access points with AT&T's cellular base stations and then using mesh radios to extend the range of the signal. Basically, the meshed radios act in concert as if they were one giant Wi-Fi hotspot. (See Wireless Mesh: Ready!)

Why this matters
Despite faster 3G and Long Term Evolution (LTE) deployments, AT&T is still expanding its Wi-Fi footprint as a cost-effective way of relieving the data pressure on its cellular network. Even Verizon Wireless -- a notable hold-out on the hotzones concept -- now plans to follow suit.

For more
Read more about AT&T's Wi-Fi ways:

— Dan Jones, Site Editor, Light Reading Mobile