Research On Quality-Awareness Concurrent Multipath Transfer (CMT)in Mobile Wireless Network

In recent years, increasing number of services and applications are widely offered to users over the wireless networks by making use of their ubiquitous access support. Mobile devices equipped with multiple network interfaces can increase their throughput by parallel transmission over multiple paths. Concurrent multipath transfer (CMT) utilizes the Stream Control Transmission Protocol’s (SCTP) multi-homing feature to simultaneously transfer data across multiple end-to-end paths. However, the different condition of the multiple paths will cause the out of order problems, which seriously degrades the transmission performance. The classic CMT strategy mainly uses a round-robin method to split SCTP packets over all available paths in an equal way without considering the path quality differences in terms of bandwidth, delay and other network parameters. Consequently, CMT suffers from significant receiver buffer blocking problems.In this paper, we introduce a novel quality awareness concurrent multipath transfer solution, which makes important contributions in the following three sections:(1) accurately senses each path’s current transmission status and estimates in real time each path’s data handling capacity;(2) designs a newly data distribution algorithm to deliver optimally the application layer data over multiple paths and ensure the received data arrives in order;(3) introduces a proper retransmission mechanism to handle different kinds of packet loss and alleviate the packet reordering problem. The simulation results show how this mechanism effectively achieves better performance and transmission efficiency in comparison with basic CMT and CMT-PF solution. Future work will consider the fairness, cross layer and handover issues of CMT.