The Advanced Mobile Phone System (AMPS), analog technology that ushered in the country's first cellular network 24 years ago, began going dark Feb. 18, leaving unprepared end-users scrambling for new solutions.

Older OnStar systems in automobiles, alarm systems and some 1 million cell phones are affected by the shutdown. A 2002 FCC ruling allows operators to shut down their analog networks and convert that spectrum for digital technologies, which are more spectrally efficient.

AT&T Mobility, Verizon Wireless and Alltel are the largest operators with analog networks. AT&T and Verizon plan to shutter their networks quickly, while Alltel will take a phased approached, ending service in September. A few small rural carriers plan to continue offering analog service.

While the impending shutdown has been known since 2002, the action six years later is catching some customers by surprise. Drivers of older General Motors automobile models who subscribe to the in-vehicle OnStar service and have analog-only telematics devices had their service shut down early, on Jan. 1. If their systems were analog/digital ready, then they are eligible for a digital upgrade. Otherwise, they are out of luck. (Vehicles made after 2005 are all digital.) GM has been warning customers on its Web site of the impending shutdown and about converting to digital technology.

Analog, because of its wide coverage area, has been built into applications ranging from fleet telematics to automated meter readers. Most of the bigger corporations have been aggressively converting their systems or had installed analog/digital modules early on, said Chris Purpura, senior vice president of marketing for Aeris, a telematics and machine-to-machine operator.

“There is almost a Y2K in 2008,” Purpura said. “Companies have to do aggressive replacement of analog.”

Purpura blames the telematics industry itself for much of the angst. Even though the analog shutdown was known about in 2002, many companies continued to ship analog-only modules until 2006, he said. “Many fleet telematics companies put in dual-mode solutions starting years ago, so the analog shutdown's no big deal for them. For others, only AMPS is deployed, so when the signal is gone, they are out of luck.”

Home alarm systems may be in the most jeopardy. The Alarm Industry Communications Committee (AICC) unsuccessfully lobbied the FCC last year for a two-year extension of the sunset rule. The AICC doesn't know how many analog alarm systems are still in operation, but a survey it conducted in 2002 indicated that fewer than 1 million home alarm systems used analog cellular to communicate with alarm centers.

“We are concerned that many smaller companies — for some reason that are unreachable — may not know. They are in denial or something,” said AICC Chairman Louis Fiore. “The mid-sized to larger companies have been very aggressive in changing out; smaller companies we've tried to reach in every possible way.”

What has complicated things for the AICC is the fact that some dealers are under the impression that their installed cellular units are “digital” and aren't affected by the sunset rule. That's because many of the analog systems use a digital subchannel of the network.

“Unless you have specifically installed GSM cellular radios, your ‘digital’ units, which use the control channel of the analog (AMPS) service will stop functioning,” the AICC warns in all-capital red letters on its Web site.

Purpura said companies need to be careful about the digital modules they select to replace their analog ones because certain digital technologies may have short lifespans. For instance, General Packet Radio Service (GPRS), a relatively slow data service used in GSM networks may be fading out as 3G networks come online. CDMA units, on the other hand, are forward-compatible, meaning they will work with future generations of high-speed CDMA networks.