Last year, word began trickling out that cellular operator T-Mobile, a unit of Deutsche Telekom, was checking into the idea of dual-mode mobile phones which could place calls both via traditional cellular networks and, where available, via W-Fi hotspots—like the 8,000+ operated by T-Mobile itself, but also subscribers’ home Wi-Fi networks, or any other open hotspot they might be near. T-Mobile has quiety been testing the service in Seattle since at least early 2007, and the results have apparently been promising: the Wall Street Journal is currently reporting T-Mobile plans to launch the dual-mode service throughout the United States as early as this June.
T-Mobile is currently testing the service with dual-mode phones made by Samsung and Nokia, and the service not only supports both cellular and Wi-Fi calling, but can transfer active calls between the two services which users shift between access points without a noticeable lag or disruption for the calling parties; much of T-Mobile’s testing has involved making this handoff as smooth as possible. The appeal of placing calls via Wi-Fi rather than cellular networks is to cut back on the comparatively expensive utilization of the cellular network for voice and data charges: by using Wi-Fi, many users will be able to significantly reduce their phone bills.
Pricing for T-Mobile’s plan, currently dubbed Hotspot at Home, hasn’t been fixed, but users in the company’s Seattle-area trial are paying about $20 a month on top of their normal mobile phone bill, plus an additional $5 for other family members on the plan.
According to the Wall Street Journal, T-Mobile is also considering offering consumer the option to connect ordinary landlines to home-based routers, setting the mobile operator in direct competition with traditional landline phone companies.
AT&T and Sprint have also tested dual-mode Wi-Fi and cellular services, but so far have not revealed any plans to offer the service to consumers.