dwidth calculations is detailed planning, which requires source data to be defined, implementing a technical solution in the IP perspective. The following activities are normally performed as part of detailed planning: IP physical connection schema towards the IP backbone; IP addressing plan for signalling over the IP; IP signalling links characteristics definition; - IP signalling link/link set property; - circuit group (CGR) mapping into the IP (IP trunk); - signalling route in IP. 4.13 Mobile Packet Core Architecture Planning The Mobile Packet Core (MPC) architecture plan consists of a logical and physical network plan. It will also contain a local area network design, management system connectivity plan, switching and routing plans and charging and billing plans. Transport Network Planning This contains the logical and physical network architecture details, load balancing schemes, network redundancy, WAN addressing schemes, IP addressing plans, QoS parameter planning, network migration plans and routing and access control configuration. This involves the planning of the Gi and Gp interfaces. Core Network Planning and Optimisation Gi is the interface between the GGSN and the external PDN while Gp is the interface between the BG and the inter-PLMN. The plans include the connectivity to the Internet service providers, corporate clients, corporate Intranet and other services/content providers. Mobility Management Mobility management (MIM) is the core of the signalling plans. As discussed in Chapter 2, MM deals with the location and state of the UE in the network. Chapter 2 describes how the BSC/RNC take care of the MM functionality; however, the SGSN is responsible for the MM within the PS service domain as the UE has the MM context for both the CS and PS core networks, which work independently of each other. There are two main features that are supported by MM: GPRS attach and GPRS detach. These two are responsible for making the UE reachable and unreachable respectively; detach informs the HLR that 3G SGSN has 