Synchronisation and Timing Groups for GSM Networks

GSM networks are optimised for voice services using compact frequency re-use schemes such as 1/1 with fractional loading. GPRS/EDGE codecs require better quality channels to support higher data throughput, i.e. channels with lower collision rates and better average carrier-to-interference ratio (CII). With the continuing growth of mobile data traffic, networks must improve channel quality in a compact re-use environment. To achieve this, we recommend the introduction of timing synchronisation for base stations (BS) in a GSM/GPRS/EDGE network. Our analysis shows that BS synchronisation leads to a reduction in collision rates that can be exploited for either C/I or capacity improvement. More importantly, we propose timing groups (TG) for a synchronized network. In conjunction with frequency planning, TG offers greater flexibility in network design by providing superior quality channels to a category of users without dividing the available spectrum into carrier groups with different re-use schemes