Research And Design On Cross-Layer And Tcp-Friendly Data Concurrent Multipath Transfer

Multihoming techniques are widely offered to employ the latest mobile devices to provision network diversity, in order to fit the definite trend towards ubiquitous and heterogeneous Internet access support. These aspects render Concurrent Multipath Transfer (CMT) as one most-preferred mode to improve the performance of wireless communications. It provides benefits of bandwidth aggregation, fault tolerance and load balance that are very attractive for future content-rich network services. However, often data reordering and loss due to network dynamicity determine CMT buffer blocking. The existing multipath scheduling solutions at transport layer only are not accurate enough because of the uncertainties of the low-layer variations at the wireless channel. In addition, CMT may occupy excessive bandwidth in comparison with popular TCP flows, which results in seriously unfair sharing of competitive network resources.This essay proposes a novel Cross-Layer and TCP-Friendly CMT solution (CMT-CL/TF) to both buffer-induced transport blocking and unfair bandwidth share use in heterogeneous wireless networks. CMT-CL/TF utilizes a cross-layer approach to monitor and analyze path quality, which includes wireless channel measurements at data-link layer and rate/bandwidth estimations at transport layer. Furthermore, an innovative window-based mechanism is applied for flow control with good balance between fairness and efficiency. Finally, CMT-CL/TF intelligently distributes data over different paths depending on their evaluated quality to mitigate data reordering and loss, under the constraint of TCP-friendly flow control. Simulation results show how CMT-CL/TF outperforms existing solutions in terms of both transport throughput and TCP-friendly fairness.