scope:

This document defines the requirements for telephone voice interconnect for Land Mobile Radio systems. The general system model given in Figure 1 of this document describes a telephone interconnect interface (Et), and it is the purpose of this document to define how telephone service is accessed through the 'Et' interface by a Land Mobile Radio system. A primary objective is to describe how control functions over the Air Interface are used for telephone interconnect services. This document only applies to those features of a telephone interconnect service which are necessary for basic telephone functionality.

Note that equipment comprising an RF Subsystem may be manufacturer-specific. Only the reference interface points are specified. Thus when referring between these requirements and the System Model Reference Configuration, shown in Figure 1, no attempt is made to allocate specific functionalities to elements such as Base Control (BC), RF Subsystem Control (RFC), RF Subsystem Switch (RFS) or RF Subsystem Gateways (RFG). Further, this document does not define the ergonomic interface to radio equipment for telephone interconnect service. Note that features and services for which support is required by this document may not necessarily be supported by the telephone network connected at the 'Et' point. Describing these features and services does not predicate their presence in the telephone network being accessed.