Effect of slot allocation mechanisms on the performance of link adaptation

Link adaptation (LA), initially developed as a 3G technique (see Dunlop, J. et al., 1995), has been identified as a key technology for evolved GSM systems. The basic principle of LA is to assess the channel conditions and then use a transport mode, from a set of predefined options, which is optimised for these conditions. The performance and operation of link adaptation depends on the channel quality dynamics. Since such dynamics are influenced by the mechanisms used to assign free slots in a TDMA system, the paper investigates the effect that different slot allocation mechanisms have on the link adaptation performance. In particular, we consider a random and a sequential slot allocation mechanism for packet data transmissions.