ation closer to the customer provides one stage of time switching to route each call from one PM premises being served (remote site). They support analogue lines via a junctor link to another NM which routes the call to the required and provide low level functions like line scanning and ringing. terminating PM. There can be up to 32 NM, each interfacing 64 A maximum of 640 lines can be connected to each LCM. Each DS30 links giving a network capacity of 64K channels. LCM consists of two shelves, known as Line Concentrating Arrays The second generation network which is now being used for all (LCA). There can be up to 320 lines connected to each LCA. new work is known as the Enhanced Network (E-net) and comprises A group of LCM connects to a Line Group Controller (LGC), a a single stage junctor-less non-blocking switching matrix of up to Line Trunk Controller (LTC), or a Remote Cluster Controller 128K channels, as shown in Figure 32.13. The crosspoint cards (RCC), which in turn connects to the Switching Network. There are 32/20 Telephone exchanges Switch network Peripheral modules E-Net Plane 0 Local or remote line module Speech Links Trunk Analogue module junctions Digital trunk controller junctions Shelf: CCS #7 peripheral Message links processor DMS Bus Input/Output DMS Core controller Maintenance System administration module position Figure 32.12 DMS (SuperNode) system a maximum of three DS30 links per LCA and a maximum of six As Figure 32.14 illustrates, there is usually some concentration of DS30 links per LCM. lines, depending on the engineering of the particular exchange. The For reliability, each Line Concentrating Array is capable of taking concentration can occur in two places: in the LCM or in the LGC. over the lines of the mate LCA. The LCAs are connected by a serial Each LGC has a maximum of ten LCM and, therefore, a maxi- data link that allows one LCA to checkpoint its data with the mate mum of 6400 (10 X 640) lines. The LGC has a maximum of 20 ports LCA. The data for each call in progress is sent to 