Evaluation of radio link selection with Analytic Hierarchy Process algorithm in heterogeneous radio networks

A multi-access radio network that efficiently utilizes radio resources is a promising approach to flexible, reliable, high-capacity communication. Regarding cooperative controlling functionality in a heterogeneous radio network, two schemes are considered to be applicable to the efficient usage of multi-radio systems: link selection and link aggregation. This paper focuses on link selection and its improvement of Transmission Control Protocol (TCP) throughput with an Analytic Hierarchy Process (AHP) algorithm in comparison with two conventional algorithms of the fixed priority scheme (Priority) and the maximum transmission rate scheme (MaxRate). Because the characteristics of transmission delay influence the behavior of the TCP protocol, the impact of three kinds of delay (RTT: round trip time, DL delay: downlink delay, and UL delay: uplink delay) are compared to find which delay is suitable for a metric of the AHP algorithm. According to the simulation results, using RTT as a metric shows 22% and 400%, at maximum, better improvement in throughput compared to MaxRate and Priority, respectively.