The connection of a user to two or more switching centers by separate access lines using a single message routing indicator or telephone number. 2. In satellite communications, the capability of a communications satellite to function as a portion of a communications link between more than one pair of satellite terminals concurrently. Note: The three types of multiple access presently used with communications satellites are code-division, frequency-division, and time-division multiple access. 3. In computer networking, a scheme that allows temporary access to the network by individual users, on a demand basis, for the purpose of transmitting information. Note: Examples of multiple access are carrier sense multiple access with collision avoidance (CSMA/CA) and carrier sense multiple access with collision detection (CSMA/CD).