5.2.5 Link adaptation for ECSD

23.0343GPPHigh Speed Circuit Switched Data (HSCSD)Release 17Stage 2TS

Link adaptation for ECSD particularly in high data rate call becomes essential in order to provide good enough service over large coverage areas. In A/Gb mode, signalling for link adaptation between channel coding schemes in 8-PSK modulation and between GMSK and 8-PSK coding schemes is done using existing signalling mechanisms, i.e. RR Channel Mode Modify procedure, intracell handover, etc. In performing link adaption between 8-PSK modulated channels, the normal Channel Mode (or the assignment or the intra-cell HO procedure) should be used and in case of link adaptation between 8-PSK modulated channels and GMSK modulated channels the assignment procedure or the intra-cell handover should be used.

In GERAN Iu mode, the Radio bearer reconfiguration procedure is used for link adaptation.