PCS, or a personal communications service, is the designation for a portion of the radio frequency band that is devoted to the use of wireless phone service in the United States, Canada, and Mexico. Here is some background on the development of the concept of the PCS, and how PCS continues to function today.
Early in the development of cell phone technology, the need to assign particular bandwidths to the signals that would be used for cellular services was evident. To this end, the need to carve out a radio band that would be for the exclusive use of cellular wireless networks was studied. Ultimately, the conclusions of the FCC in the United States and Industry Canada was that the designation of the 1850-1990 MHz range for use with cellular telephone service would ensure there was no interference with frequencies that were used for public broadcast or governmental functions. During 1994, both countries established the 1900 MHz band as the standard for use in any wireless network based for service in the United States or Canada. This effectively created the first unified PCS on the market.
While this helped to ensure that the new technology did not interfere with other bandwidth uses, and also helped to make the process of interacting with a wired network easier, this did not address the issue of cellular phone interaction with European and Asian locations and services. Over time, the development of dual band phones that allowed for signals to be processed that would accommodate both North American standards and other worldwide standards to be compatible. Sometimes referred to as multi-band GSM systems, many parts of the world now use PCS as a term to describe GSM services that operate in the 1900 MHz range.
In the United States, Sprint was the first service provider to establish true PCS service, working with a base station that anchored service in the Baltimore-Washington DC area of the country. The station was actually configured to operate with GSM-1900 standards, which made it possible to utilize the service with international calling. Over time, Sprint upgraded to CDMA technology for their cellular network that rendered the base obsolete, although they continued to provide signaling within the now defined PCS range. Today, just about every cellular provider within the continental United States operates within the PCS range of 1850-1900 MHz, which has made many of the contemporary features of cell phone plans possible, as they relate to interaction with other wireless networks.