T-Mobile wants to replace your landline with its HotSpot @Home Wi-Fi service

Around the same time Apple was shaking up the mobile market with the iPhone launch, T-Mobile announced its plan to merge Wi-Fi and cellular communications. T-Mobile's HotSpot @Home service will allow customers to place VoIP and cellular calls from a single mobile phone.

To use T-Mobile's HotSpot @Home service, you need a broadband connection, a wireless router, and one of two phones designed for the HotSpot @Home service. When you're within range of your home's Wi-Fi network or a T-Mobile HotSpot, all incoming and outgoing calls are placed using the phone's wireless VoIP-like technology. If you travel out of the Wi-Fi area, the phone automatically transfers your call to T-Mobile's GSM/GPRS/EDGE wireless network. Likewise, if you start a call on T-Mobile's cellular network and travel into a T-Mobile Wi-Fi HotSpot, the call will move with you. The transition is seamless. Unless you watch the phone during the process, you won't notice the switch.

T-Mobile's HotSpot @Home service uses Unlicensed Mobile Access (UMA) technology to bridge the Wi-Fi and cellular network. You can learn more about how UMA works and which companies are exploring this technology at Umatoday.com.

Two phones are currently available for the HotSpot @Home service; the Samsung T409 and Nokia 6086. Each phone costs $49.99 with a two-year contract. T-Mobile offers a preconfigured Linksys WRT54G or D-Link DI-524 wireless router--free with a rebate when you sign up for the program. You can also use your existing 802.11 b/g wireless router. You'll need to purchase a regular T-Mobile service plan in addition to the HotSpot @Home service, which costs $9.99 a month for a single line or $19.99 for a family plan.

HotSpot @Home subscribes get unlimited nationwide calling when the calls originate from a Wi-Fi network. If the call originates from the cellular network, the talk time applies to the T-Mobile service plan's minutes. So, when you place a call while driving home, be sure to hang up and call back once you arrive. Otherwise, you'll be using your plan minutes even though you're talking on your Wi-Fi network.