Pulse Code Modulation.  Form of modulation used in the PSTN
Personal Communications Services.  Standard of mobile system.  Digital technology that offers superior sound quality and the capacity for multiple communications services, such as voice, paging, text messaging, and wireless data transmissions.
A Mobile Station that follows PCS mobile system standards.  Uses digital technology enabling various services and data transmissions.
Personal Communications Services.  Standard of mobile system that operates in the 800 MHz frequency range.
Ericsson’s upbanded (1900 MHz frequency range) D-AMPS service offering digital technology (superior sound quality and the capacity for multiple communications services, such as voice, paging, text messaging, and wireless data transmissions).
Personal Digital Cellular.  Standard defined by the mobile system in Japan.  Digital.  Operates in the 800-1500 MHz range, uses TDMA/FDM access method, FDD duplex method, and has 1600 channels (3 users per channel.
Public Land Mobile Network.  The network formed by the cellular system.  The components of this structure consist of cells, Location Areas (LA), Service Areas (SA).
The area inside which the service will be provided by one network operator.  These areas may overlap geographically, e.g., where different companies operate networks within the same country.
Public Switched Telephone Network.  A vast wireline telephone system of switches and other components that route landline calls.  It includes local exchange and long-distance carriers, but not mobile telecommunications networks.
Portable Wireless Telephone.  Digital mobile system that operates in the 1880-1900 MHz frequency range.  TDMA/FDM multiple access method.  Also known as DECT.
The process of informing an MS that a call is coming in to that MS.
A mobile telecommunications product offering alphanumeric capability and many features including access to current news and weather, connection to a toll free number and voice mail.
The steady decrease in the power of a signal as the distance from the transmitter increases. 
Active Mobile Stations send signals to the MSC at regular intervals.  Registration can be triggered by specific events such as call origination, termination, MS power on, or moving between service areas.
Standard of mobile system.  Digital technology that offers superior sound quality and the capacity for multiple communications services, such as voice, paging, text messaging, and wireless data transmissions.
A cell that has a range of the floor of a building or smaller.
Private Numbering Plan (PNP) allows a group of users to define a common, abbreviated numbering plan which can be used to shorten dialed numbers.
Ericsson systems and services for transmitting voice, data, text and images over public networks.