A Proposal of Multipath Reliable Communication Technique Considering Unstable Links

摘要

Recently, with advances in cellular phones and wireless LAN technologies, mixed environments consisting of a fixed network and a wireless network have become commonplace. Also, information networks represented by the Internet are now indispensable for daily life. Hence, demands for highly reliable communications in a mixed environment of fixed and wireless networks have increased. However, wireless networks have the problem of easily generated packet loss due to various factors such as obstacles and interference. In a network consisting of a link with a high packet loss rate and high instability, the end-to-end packet arrival rate is significantly degraded. In addition, the entire network may become unstable due to frequency updating of the paths as a result of losses in routing control packets. To enhance the packet arrival rate, it is effective to use a multipath communications system in which several copies of the packets are sent by different paths. In this paper, based on path design considering the introduction of the intermittent state as a link condition, and introduction of the concepts of interruption-tolerant path and route calculation considering interference, a multipath communication system is proposed that enhances the end-to-end packet arrival rate while the control load is reduced in a network consisting of unstable links. By means of simulation it is shown that the control load can be kept small during communications while the packet arrival rate is improved over that in the conventional system.