alysis and results. Digit Analysis and Routing in the MSS System The primary function of digit analysis and routing in MSS system network elements is to find free resources in the network to direct user traffic, voice and data connections to the desired destination. Digit analysis determines the destination of a call and selects an external route to the destination. It analyses the digit sequences that it receives. Typically the received sequence is the address of the receiving end (E.164 number, AESA address). Digit analysis is used to find the correct route to a destination that is requested by an MSS. Digit analysis gets the address of the other network element and finds the route for the destination by analysing the address. In brief, the digit analysis process in the MSS system can be described in a call example, as shown in Figure 4.35. Core Network Planning and Optimisation Considering a call from subscriber A in MSS1 to subscriber B in MSS2, then MGW1 and MGW2 are controlled by MSS1 and MSS2 respectively. Digit Analysis in MSSI The analysis of the incoming call (in tree 2) results in a special route of the HLR enquiry. This results in the subscriber B roaming number being returned to MSS1. The analysis of roaming number (in tree 50) results in an outgoing route to MSS2. Besides the roaming number of subscriber B, the BNC-ID (bearer network connection identifier) and BIWF address of MGW1 are also sent to MSS2. Digit Analysis in MSS2 The analysis of received roaming number (in tree 50) results in a special route of paging subscriber B. MSS2 sends the BNC-ID and BIWF address of MGW1 to MGW2. Digit Analysis in MGW2 The analysis of the received BIWF address of MGW1 from MSS2 (after the digit analysis process in MSS1 and MSS2) results in the establishment of a bearer network connection with MGW1. Digit Analysis in RNC1 The analysis of the received BIWF address of MGW1 from MSS1 (during the RAB assignment request) results in the establishment of a bearer network connection with MGW1. Digit Analysis in RNC2 The a