d since the first ex- change was brought into service in 1977, but the ever changing 1. As Base Station Controller (BSC). telecommunication arena constantly provides new demands. Table 2. As Mobile Switching Centre (MSC). 32.1 gives some examples of already ongoing changes, including 3. As Visitor Location Register (VLR). the possibility of digital access to voice and data services. 4. As a transit switch interconnecting the MSCs and to provide access to the fixed network. 5. As a Service Control Point (SCP) for IN (Intelligent Network) functionality (the service control functionality can also be inte- Table 32.1 Changes in telecommunication requirements grated on the MSC or transit layer). 6. As an operator exchange for manually assisted calls. The mobile applications covered by AXE also encompasses func- tionality for Personal Communication Networks (PCN). Node defined switching Network wide services Copper bandwidth Fibre bandwidth 32.10.6 Intelligent Network (IN) Node intelligence Intelligence diffused through the entire network The AXE/IN architecture consists of six functional levels: In band signalling Common channel signalling Standard services Customised services 1. Basic switching. Wire access Wire and radio access 2. Service switching. 3. Service control. Local/regional standardisation Global standardisation 4. Network management. Monopolistic regulation Competitive markets 5. Service management. 6. Service creation. Circuit switching A mix of circuit and packet switching The first three layers are implemented in AXE. The last three in a Narrowband services A mix of narrowband, specially tailored Service Management System (SMAS). wideband and broadband The central processor in AXE is by nature a real time, high services availability computing system, optimised for use within telecom- Calling defined locations Calling personal numbers munications networks. It fits with the intelligent network applica- Plesiochronous transmission Synchronous transmission DMS system 32/19 32.11 DMS system comprising the m