scope:

The prcsenL doeumelll specifics the layer 3 procedures used on the Base Station System (BSS) lO Mobile-services Switching Cemre (MSC) interface for conu'ol of GSM services.

For the purposes of call conU'ol and mobility management. messages arc nOt interpreted at the Base Station System (BSS) which acts as a relay function. These messages and procedures arc documemed in 3GPP TS 04.08. the only relevant issues coveling these messages in the present document arc those concerned with error conditions at the illlerface, and the headers that arc required for the correct addressing of the messages. This is specified in more detail in 3GPP TS 08.06.

The functional split between MSC and BSS is defined in 3GPP TS 08.02 and states that the BSS is responsible for local radio resource allocation and in order lO supp0!1this the required procedures between BSS and MSC are defined in detail in the present document.

3GPP TS 08.02 also states that the BSS is responsible for the scheduling of all CCCH/BCCH  messages and therefore some procedures for providing the BSS with the necessary infonnation to be passed on these channels for individual calls (Le. paging) are defined in the present document, but the scheduling is not discussed.

This interface and consequently these layer 3 procedures are designed lO support BSSs providing one or more cells.