Most iDEN handsets are built to withstand rougher treatment than your average cell phone, but the venerable network itself will finally bite the dust within the next few years.
As part of a plan to consolidate its networks using new equipment that can serve multiple radio bands and technologies, Sprint said Monday it expects to begin phasing out iDEN in 2013. In the meantime, Sprint will shift the PTT (push-to-talk) service for which the technology is famous to its CDMA (Code-Division Multiple Access) network.
Nextel Communications adopted Motorola's iDEN technology in 1996 to build a cellular service that became popular among business users and in blue-collar fields such as plumbing and construction. Its national network was pieced together from a few early regional carriers and Motorola spectrum licenses for two-way radios.
Nextel was popular because its phones were rugged and incorporated PTT, which could take the place of the walkie-talkie radios often used by workers in the field. Partly as a result of that business customer base, Nextel was envied for its high per-user revenue. It also used iDEN for its low-cost, prepaid Boost Mobile service.
Sprint, which also served many business users, merged with Nextel in 2005.
The newly formed Sprint Nextel reassured subscribers that it would keep iDEN running until at least 2007. The network has already outlived that commitment by three years, even as its users have fled in large numbers. In the third quarter of this year, counting customers of its own brands, Sprint reported a net loss of 383,000 postpaid and 700,000 prepaid iDEN subscribers, ending with a total of 6.1 million postpaid and 4.5 million prepaid customers on the network. In the same period, Sprint's own-brand CDMA services gained subscribers. Nextel had more than 15 million subscribers when it merged with Sprint.
But the iDEN network is finally succumbing to the passage of time and advancements in technology. While Sprint and other U.S. carriers operate national networks that run at 500K bps (bits per second) or more, and are migrating to multimegabit "4G" systems, iDEN's data throughput averages 20K bps to 30K bps.
"iDEN is this really scrappy technology that allowed [Nextel] to turn little, worthless pieces of spectrum in a local area into a nationwide gold mine," said Nielsen Co. analyst Roger Entner.
As more former walkie-talkie users adopted the technology, it became a standard within certain trades, said NPD Group analyst Eddie Hold. Those in the trade expected to be able to use Nextel PTT, with its distinctive two-beep alert, to contact co-workers or subcontractors.
"It was the first social network. It was the professional social network," Hold said.
Another advantage was that PTT calls were free, Entner pointed out.
Seeing the loyal and lucrative customer base rallying around Nextel and Motorola, which were effectively the only purveyors of iDEN, other vendors and carriers developed their own PTT systems. Those alternatives have never been hugely successful, partly because of the value of that social network around iDEN, according to Hold.
"It was really hard for one person to say, 'I'm switching,'" Hold said. "Once you were in it, it was too painful to get out of it."
In addition, Nextel's PTT had a big edge in quality, at least while other carriers were still using 2G (second-generation) cellular networks, Hold said. That edge narrowed as rivals deployed 3G, but PTT from other carriers still didn't catch on, he added.
But with the advent of free in-network calling, the cost advantage of PTT also diminished, according to Nielsen's Entner. The even bigger threat to iDEN was the high-speed data capabilities that 3G offered. Entner recalled talking to iDEN's backers in 2002.
"I said, 'You guys will be fine until the day people want to have a lot of data.' And those days are here," Entner said.
Despite iDEN falling farther behind other networks in speed, Sprint had shown continued support for the system in recent years. In 2008, the company said it would keep investing in the network until at least 2012, and last year it introduced NextMail Locator, a feature for workers in the field that attaches GPS (Global Positioning System) coordinates to a voicemail message so co-workers can see where the user was at the time of the message. Motorola also continued to introduce iDEN handsets.
Now, Sprint plans to introduce a next-generation PTT service on CDMA next year, featuring sub-second call setup time and better data capabilities, and shift more PTT users to the 3G network over time. With its new, consolidated infrastructure, the carrier also plans to gradually repurpose Nextel frequencies in the 800MHz range -- a band that may provide better in-building coverage than Sprint's 1.9GHz spectrum -- to other services. Though the iDEN spectrum began as a hodgepodge of frequencies, it's now more coherent and easier to reuse because of a deal Nextel made with the U.S. government in 2005 to remove interference with public-safety networks, the carrier said.
Though discontinuing iDEN is an idea whose time has come, it will be an expensive project if Sprint wants to retain the remaining subscribers, analysts said. It may be even harder to bring along Boost customers than Nextel subscribers, according to Hold. The migration is likely to look like carriers' earlier strategies for phasing out analog networks, Entner said.
"If Sprint really wants them off, then they have to buy them a new phone," he said.