T-Mobile switches on ISP-hotspot piggy-backing

T-Mobile customers in the Tampa and Orlando, Florida areas could be about to receive a windfall.

Those who opt in to the MNO’s trial of automatic, hotspot piggy-backing won’t have that hotspot bandwidth eat into their plan’s data allotment, according to TmoNews, a PhoneDog-owned website covering T-Mobile.

Bright House

T-Mobile is partnering, in a test, with Bright House, the second-largest cable operator in Florida, to offload mobile traffic onto the ISP’s fixed, cabled hotspots.

T-Mobile says in support documents on its website that Bright House has about 34,000 hotspots in the areas.

The “Preferred Wi-Fi Network” as T-Mobile calls it ostensibly gives customers automatic, extended coverage for mobile devices when in range of a hotspot. But it also helps the MNO by alleviating network capacity strain on crowded spectrum.


The heart of the system, called Passpoint, was developed by the Wi-Fi Alliance, an association of Wi-Fi companies, and lets Wi-Fi users more easily connect to Access Points (APs) without passwords. They can then roam seamlessly from one AP to another.

Passpoint was introduced in 2012, according to a FierceWirelessTech article about the roaming technology.

However, deployment thus far has been predominantly for data users in the Wi-Fi hotspot market, rather than for MNO-derived mobile calling. Mobile hotspot provider Boingo, for example, along with cable provider Time Warner, uses Passpoint to provide reciprocal hotspot data roaming.


Where T-Mobile’s implementation of Passpoint is different from what gone before is that it’s a major mobile network offload.

In other words, it isn’t just for data sessions at hotspots, along with occasional app-based calling, but is a total mobile calling solution with seamless call handoffs—if you have the right equipment.

Voice over LTE, or VoLTE, mobile devices where the voice call is sent over LTE as IP data, will not drop calls, if used in a VoLTE cell, T-Mobile says on its website.


Wi-Fi calling itself isn’t new and end-users like it. I recently wrote about an Ericsson survey that indicated that people made longer and more frequent calls with Wi-Fi rather than mobile networks—the quality was better, they thought.

A lack of handoffs has been an impediment though, and the survey respondents said that they don’t like it when the call gets dropped as they move around.

VoLTE along with Passpoint, as used in this T-Mobile test, should fix that.


The Bright House Networks and T-Mobile mix has a secondary benefit too, over the traditional Wi-Fi calling, in that theoretically the MNO has some control over quality—it has a relationship with the network.

With ad-hoc Wi-Fi calling it doesn’t, and potential poor quality reflects on the MNO.

Cable alliance

“Bright House is also a member of the CableWiFi Alliance, which was formed in 2012 by Bright House, Cox Communications, Charter Communications, Time Warner Cable and Comcast to support roaming among the cable companies' public Wi-Fi hotspots.

“T-Mobile's test appears to indicate the wireless carrier's intention to tap into that public Wi-Fi network to improve its coverage,” FierceWireless said in an article about T-Mobile’s Passpoint tests.

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