Since the AMPS standard is analog technology, it suffers from an inherently inefficient use of the frequency spectrum. All AMPS carriers have converted most of their consumer base to a digital standard such as CDMA2000 or GSM and continue to do so at a rapid pace. Digital technologies such as GSM and CDMA2000 support multiple voice calls on the same channel and offer enhanced features such as two-way text messaging and data services.
Unlike in the United States, the Canadian Radio-television and Telecommunications Commission (CRTC) and Industry Canada have not set any requirement for maintaining AMPS service in Canada. Rogers Wireless has dismantled their AMPS (along with IS-136) network, the networks were shut down May 31, 2007. Bell Mobility and Telus Mobility, operate AMPS networks in Canada, they have announced that they will observe the same timetable as outlined by the FCC in the United States, and as a result will not begin to dismantle their AMPS networks until after February 2008.
OnStar relies heavily on North American AMPS service for its subscribers because, when the system was developed, AMPS offered the most comprehensive wireless coverage in the US. ADT recently asked the FCC to extend the AMPS deadline due to many of their alarm systems still using analog technology to communicate with the control centers. Cellular companies who own an A or B license (such as Verizon and AT&T Wireless) must still provide analog service until February 18, 2008. After that point, however, most cellular companies will be eager to shut down AMPS and use the remaining channels for digital services. OnStar is transitioning to digital service with the help of data transport technology developed by Airbiquity, but warns customers who cannot be upgraded to digital that their service will permanently expire on January 1, 2008.
But still there are a lot of cell phones, home security systems and car alarm services using analog transmitters. Home alarm systems are most vulnerable, as providers report having customers in areas with little to no GSM reception.
This step is intended for accelerating the process of entering the digital era.