On the need for buffer optimization strategies for inter-session network coding

During the past decades inter-session network coding for wireless network has been proven to be an effective tool being capable of providing a many-folded gain in terms of throughput. In order to utilize the full potential of inter-session network coding, any coding node needs to operate in an ideal wireless environment that provides equal flow of incoming packets. However, such an ideal wireless environment is seldom seen in a real world scenario. In this work, we address one of the issue that may arise in a non-ideal wireless environment, namely asynchronous packet arrival at the relay leading to an inefficient coding gain. To overcome this, we present a buffer enhancement structure at the coding node that guarantees an equal packet distribution of the codable flows. This structure is implemented on our test platform and using it, we performed a real-life measurement. Our measurement results show that by ensuring an equal packet distribution at the relay yields an improvement in terms of system throughput in compare to an unequally distributed packet buffer structure.