Bandwidth Scheduling for Multipath TCP Based Concurrent Multipath Transfer

Concurrent multipath transfer (CMT) can achieve bandwidth aggregation by employing multiple TCP subflows in a connection. However, constrained by the transport layer protocols such as Multipath TCP, the throughput cannot increase linearly with bandwidth, which means bandwidth resources cannot be fully utilized. To improve the spectral efficiency, in this paper we propose a bandwidth scheduling scheme by allocating appropriate spectral resources for each link. Firstly, the concept of validity bandwidth (VBW) is employed to estimate the required size of bandwidth based on Mathis Model. Secondly, the Kalman Filter is applied to smooth the value of VBW caused by dynamical changes of network status. The simulation results demonstrate the effectiveness of our proposed scheme in achieving a tradeoff between throughput and spectral efficiency. With path loss rate varies, the spectral efficiency improves by 92.6%. while the corresponding throughput suffers a decline by 17.4%. When delay changes, the biggest gap occurs at 100ms with 14.1% decline in throughput and 89.5% growth in spectral efficiency.