TCH.4 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 Dynamic Abis Pool TCH.5 TCH.6 TCH.7 TCH.8 TCH.1 TCH.2 TCH.3 TCH.4 TCH.5 TCH.6 TCH.7 TCH.8 TRXSIGI OMUSIGI TRXSIG2 OMUSIG2 TRXSIGI OMUSIGI TRXSIG2 OMUSIG2 TRXSIG3 OMUSIG3 TRXSIG4 OMUSIG4 TRXSIG3 OMUSIG3 TRXSIG4 OMUSIG4 TRXSIG5 OMUSIG5 TRXSIG6 OMUSIG6 TRXSIG5 OMUSIG5 TRXSIG6 OMUSIG6 TRXSIG7 OMUSIG7 TRXSIG8 OMUSIG8 TRXSIG7 OMUSIG7 TRXSIG8 OMUSIG8 TRXSIG9 OMUSIG9 TRXSIG10 OMUSIGIO TRXSIG9 OMUSIG9 TRXSIG10 OMUSIGIO TRXSIG11 OMUSIG11 TRXSIG12 OMUSIG12 TRXSIG11 OMUSIGII TRXSIG12 OMUSIG12 'Static' Abis 'Dynamic' Abis Figure 6.4 'Static' and 'dynamic' Abis A group of these dynamic Abis channels is known as a 'dynamic Abis pool' (DAP). A DAP consists of a minimum of one time slot, while the maximum may depend on the system capability within one PCM. With EDGE transceivers, the BSC allocates Abis capacity for data calls from the EGPRS dynamic pool (EDAP) when needed, i.e. when MCS-3 or higher is used. Standard GPRS (non-EGPRS) calls using CS-2, CS-3 and CS-4 can also use EDAP resources when allocated into EGPRS territory (EDGE transceivers). Time-slot Allocation in Dynamic Abis Time-slot allocation in the Abis interface of an EDGE transmission network is almost the same as in GSM/GPRS networks. Traffic channels on the Abis still occupy 16 kbps sub-time slots for voice, and data rates up to 16kbps. However, for data rates above 16 kbps, one master sub-time slot of 16 kbps and up to four sub-time slots from the DAP are required, as shown in Figure 6.5. Th