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Marrying the Cellphone to Cheap Internet Calling
Matthew Miller had some problems with a T-Mobile service.
By GLENN FLEISHMAN
SEATTLE
MATTHEW MILLER wanted to cut the cost of his cellphone plan. He and his wife, Dayna, had regularly exceeded their 2,000-minute-per-month T-Mobile family plan, incurring extra-use charges that reached $60 some months.
With her home business and his daily commute of two and a half hours to his job in Seattle, they decided this year to move to the maximum 3,000-minute plan. They spend another $20 a month for unlimited long-distance calling on their landline.
Mr. Miller, a columnist for Geek.com and ZDNet in his spare time, was therefore not surprised when T-Mobile asked the couple to join an early local test of a service that combines the ubiquity of cellular networks with the flat pricing for unlimited calls available with some Internet-based phone services.
The new service, HotSpot@Home, allows a subscriber to place calls from a mobile phone using cellular and Wi-Fi networks, whether a home wireless network or a hot spot operated by T-Mobile.
In my own testing, I found the service a reasonable first draft of what could become a reliable alternative to both all-cellular networks and an emerging set of Wi-Fi-only phones. The marriage might even save money — for both T-Mobile and its subscribers. Carrying calls over Wi-Fi networks costs the company as little as 20 percent of the expense of calls handled on a cellular network.
All calls originating on a Wi-Fi network to numbers in the United States are included in a monthly fee of $20 for a primary phone and $5 for additional phones in a family plan. The Wi-Fi plan must be coupled with a traditional voice cellular service plan of at least $40 a month.
Although T-Mobile introduced the service in late October, after the tests in which the Millers took part, the company allows subscribers to sign up only in the Seattle-Tacoma region, and only at corporate stores. The service can be used nationwide, however.
The company, based in Bellevue, Wash., declined to comment for attribution for this story, citing its intention to keep interest in the service low until it is nationally available. I tested this service as a walk-up customer at a mall kiosk paying retail price.
The service is designed to pass calls in progress from a Wi-Fi network to the cellular network (or vice versa) when a signal drops in strength, in the same fashion that regular cellphones hand off among many cell towers. To a suitably equipped telephone, Wi-Fi is just another cell tower.
Providing calls over Wi-Fi also has the potential to improve voice quality in often hard-to-serve interior spaces in detached homes and apartment buildings.
While corporations have used telephone handsets or base stations that route calls exclusively over Wi-Fi, those networks require expensive server equipment to ensure call quality, roaming and capacity. Telephones for these networks typically cost at least $300 to $500.
T-Mobile’s service, by contrast, works over networks using much less expensive equipment, including existing home Wi-Fi gateways, as well as a router that T-Mobile offers for free to subscribers after a $50 mail-in rebate. Further, its subscribers bear the cost of the home network broadband connection.
Other Wi-Fi phones have appeared in great variety in recent months, with several models appearing that tie into Skype, the eBay-owned service that dominates free computer-to-computer calling worldwide. For a variety of per-minute and flat-rate fees, Skype also offers calling to and from the public switched-telephone network.
These Wi-Fi-only phones lack cellular radios, and often have difficulty in connecting to Wi-Fi networks that are not completely free and open, or are not operated by the phone’s owner. (Some smartphones feature both cellular and Wi-Fi radios, including several Nokia models sold primarily outside the United States, but carriers that support these phones do not offer hybrid calling plans.) For the T-Mobile service being offered in Seattle, with its dual Wi-Fi and cellular ability, the choice of phones is limited, although more are expected to appear throughout 2007. HotSpot@Home requires either the Nokia 6136 or the Samsung SGH-T709. Both are $30 after a $50 mail-in rebate.
The phones automatically connect to T-Mobile hotspots, and can scan and be configured to connect to any open Wi-Fi network or one secured with a home Wi-Fi security method.
Because the service uses an international standard (Unlicensed Mobile Access) focused on voice, the phones perversely cannot use Wi-Fi networks for data access, and laptop access to T-Mobile hotspots is also not included in the HotSpot@Home plan.
Information services offered with the phones, including a typical minimally featured Web browser, require T-Mobile’s low-speed GPRS or slightly faster EDGE cellular data network. Access to those networks adds $20 a month for unlimited use.
This also means that a free network that requires a button click to gain access is off limits to the service. I tried to test the phone on a commuter bus line through Seattle that has a trial Wi-Fi-based Internet connection on board. But I was stymied by the inability to click “I Accept.”
Nevertheless, I used a Nokia 6136 over a swath of Seattle, including inside homes and offices, and at hot spots run by T-Mobile and other providers. Call quality was excellent on all Wi-Fi networks tested, including full-duplexing — better described as the Robert Altman effect — in which both parties are speaking at the same time but can hear each other clearly.
Roaming, however, was far from acceptable. The cellular-to-Wi-Fi handoffs worked most of the time without interruption to a call in progress. But most Wi-Fi-to-cell transitions caused a dropped call as the hot spot signal ebbed with distance.
The Millers experienced regular call drops during calls placed on the Wi-Fi connection; they tried both the Samsung and Nokia models. Another user, Monica Paolini, a cellular and wireless industry analyst, has found her Samsung phone “sometimes ‘forgets’ about Wi-Fi and it needs to be rebooted.”
These rough edges in roaming and call continuity can be smoothed over time through software updates performed over-the-air to the phone — something cellular carriers already carry out on a regular basis for all their phones — and through tweaks to the handoff systems on the cellular network. T-Mobile is expected to make these improvements before expanding its potential subscriber base.
Ms. Paolini uses the phone with a D-Link Wi-Fi router sold by T-Mobile and with a second Wi-Fi network in her home. The D-Link router includes two features intended to improve call quality and battery life.
The first feature, WMM (Wireless Multimedia), can give higher priority to voice data — as well as streaming media — traveling over a Wi-Fi network to reduce the chance of stuttering or delays.
The second feature, a subset of WMM called Power Save, lets a handset reduce radio power whenever it is not actively transmitting or receiving.
This can increase battery life by 15 to 40 percent over standard Wi-Fi, according to the Wi-Fi Alliance, an industry trade group that provides WMM certification and device approval.
Mr. Miller said that after the several weeks of testing, he signed up for the commercial service from T-Mobile, only to drop it within the two-week cancellation period. He and his wife were unable to get consistent connections to the Wi-Fi router with either the Nokia or Samsung phone, and were unhappy with the limited battery life and the call dropping.
“If it wasn’t dropping calls and frustrating her from that aspect, we probably would have stuck with it,” he said. He would consider the service again if he was confident that it had improved.
T-Mobile may be eager to convert and retain customers like the Millers and me. When I canceled my service after testing, a store manager offered to pay $350 in cancellation fees my current provider would have charged, sweetened further with a $100 use credit after a year’s service.
While that offer is not unheard-of to lure a switcher — carriers can pay $300 or more in customer acquisition costs — it may show how eager the company is to further its trial program here before trying to sell the rest of the nation on Wi-Fi calling.
