An Adaptive Frame Length Aggregation Scheme in Vehicular Delay-Tolerant Networks

Vehicular delay-tolerant networks (VDTN) experience high-speed mobility and volatile topology on a large scale. Therefore, VDTN may not guarantee end-to-end connections. This gives the MAC layer the opportunity to adapt its transmission strategy to the current unstable wireless connections in order to improve transmission efficiency. We propose an adaptive frame length aggregation scheme in VDTN in order to improve transmission efficiency and increase data throughput. In our scheme, suitable aggregation frame lengths are calculated according to the current wireless status, and are applied in the MAC layer at the initiation of the data transmissions. We analyze and apply our adaptive frame length aggregation strategy to the current frame aggregation schemes in 802.11. Our simulations demonstrate improved results in data throughput, retransmissions, and transmission efficiency, compared to nonadaptive aggregation schemes.