Radio Aware SCTP Extension for Handover Data in EGPRS

SCTP is a transport protocol that is used in wired networks to transport PSTN signaling. It provides interesting features (namely multihoming and multistreaming) to enhance the performances of information transport over cellular networks air interfaces (S. Kang and M. Fields, 2003). Some additional extensions have been defined to adapt SCTP in a wireless context (mSCTP) (W. Xing et al., 2002). However current approaches do not take into account radio information in cell reselection/handover process. This study proposes a new extension for the SCTP protocol which aims at improving the transport performance in wireless environments. We define for that purpose a new control chunk (named Qos_measurement_chunk). It allows the emission of radio information from the mobile to the SCTP peer in the network. These information can be used by the SCTP layer to adapt the transmission rate to the current radio transmission conditions (particularly useful in handover/reselection situation). The combined use of Qos_measurement_chunk and of the multihoming feature provide a data handover with a performance improvement. The obtained simulation results are compared with the standard SCTP and present better performance in terms of data throughput in the access network