Flexible layer one for the GSM/EDGE radio access network (GERAN)

In Release 6 of the 3GPP standards, a major enhancement of the physical layer is being designed for the GSM/EDGE radio access network (GERAN): the flexible layer one (FLO). The main advantage of FLO is that the configuration of the physical layer is specified at call setup. Consequently support of new services such as the IP multimedia subsystem services can be handled smoothly without having to specify new coding schemes for each release. Through several enhancements, the radio bearers offered by FLO fulfils the IMS requirements in terms of flexibility and performance, and also improves the link level performance of real-time IMS services compared to GERAN Release 5. This paper describes the proposed architecture for FLO, highlights the commonalities with UTRAN and presents the gains it provides for the support of real time services compared to Release 5.