P Identifier Interface Type Administrative State unlocked Maximum Bandwidth (ingress) 150000 Maximum Bandwidth (egress) 150000 Maximum VCI Length In Bits Figure 3.74 Connection configuration (CoCo)-ATM Interface Transmission Network Planning and Optimisation Interface ID (13) Value VPI: (2) Default Peak Cell Rate (Ingress) Common NBAP links (1) Default Peak Cell Rate (Egress) TP ID: 1 VCI: 56 Default CDVT (Ingress) Dedicated NBAP links (1) Default CDVT (Egress) Service Category Constant bit rate (CBR) AAL2 signalling links (1) Conformance Definition Constant bit rate 1 (CBR_1) AAL2 user plane links (1) Early Packet Discard Disabled Partial Packet Discard Disabled Quality of Service Class QoS Class 1 Figure 3.75 Connection configuration (CoCo)-D-NBAP links signalling links should also be determined, including the priority. Parameters are defined for signalling links, signalling link sets, routing and also for signalling sublayers. An example is shown in Figure 3.75 (where CDVT is the cell delay variation tolerance and D-NBAP is the Dedicated Node B Application Protocol). 3.14 Transmission Network Optimisation To start with, two things need to be specified. What is meant by transmission in this context and what is really meant by optimising it? This might sound like hair-splitting but unfortunately transmission optimisation and transmission optimisation in cellular networks are loosely used phrases that are heard often but very seldom (if ever) made clear as to what is really meant. It is evident that the purpose is to improve something and that there is a willingness to do this, but that is about as far as it gets before the situation becomes fuzzy. 3.14.1 Definition of Transmission To get started, it is important to acknowledge that when talking about transmission optimisation in cellular networks the discussion concerns a very special kind of transmission solution and a very narrow implementation of transmission. Transmission as a word just suggests that some information is being moved from one place to another 