Dynamic packet fragmentation for wireless channels with failures

It was shown recently [7?9], under quite general conditions, that retransmission-based protocols may result in power-law delays and possibly zero throughput even if the distribution of packets (data units) is very concentrated, e.g., exponential or Gaussian. This phenomenon occurs irrespective of whether the cause of retransmissions is due to channel failures in the data link layer [7] or collisions in ALOHA-type protocols in the MAC layer [9]. These theoretical findings are in agreement with empirical measurements in [18], showing that the utilization of the 802.11 protocol is only 40%, basically due to retransmissions. In order to alleviate this problem, we propose a new dynamic packet fragmentation algorithm that can adaptively match channel failure characteristics. This algorithm is based on the mathematical insights developed in [7, 8]. As a first order approximation to the channel dynamics, we assume that the channel is either available for a period of time or unavailable. Then,...

• Type: Conference
• Year: 2008
• Where: MOBIHOC
• Authors: Predrag R. Jelenkovic, Jian Tan
• Keywords: Channel Availability Periods, Fragmentation Algorithm, MOBIHOC 2008, Packet Fragmentation Algorithm, Wireless Networks