TIA EIA/IS-41.2 PDF

Intersystem handoff uses dedicated voice and data facilities between the MSCs. Future versions may use other facilities. Handoffs are allowed to traverse from system to system with the total number of switches in the sequence limited to the value of a parameter which is programmed by the service providers. No attempt 1s made to detect inefficient or unnecessary trunking beyond abutting systems. Path minimization is limited to handbacks to abutting systems. No provision is made to optimize or collapse paths, such that two (2) or more systems are removed at one time. (This does not prevent a target system from detecting a returning CSS and truncating the path.)

All handoffs and contractions between systems are incremental. This feature is manufacturer and system independent. This protocol does not preclude handoff between bands A and 8 within the same Cellular Geographic Serving Area (CGSA).

In general, custom calling features and other features are not supported in this version. No remote feature use or control is allowed. Existing calls using custom features may be involved in intersystem handoffs as long as no feature support is required across systems.

An off-hook CSS is a unit that is currently involved in a call. Only off-hook CSSs may handoff. A CSS that is in the alerting state will not be handed off.