MAC-PDU Size Optimization for OFDMA Modulated Wireless Relay Networks

Hop adaptive MAC-PDU (Protocol Data Unit) size optimization is proposed for Orthogonal Frequency Division Multiple Access (OFDMA) based wireless relay networks. Such optimization improves the end-to- end goodput via MAC-PDU size optimization. We provide design and evaluation for two hop cellular networks with fixed relays where the Base Station (BS) to Relay Station (RS) links are potentially robust and are Line of Sight (LOS). The proposal reduces the total overhead transmitted in the end-to-end path via transmitting longer length packets in the potentially robust BS-to-RS links. The link level simulations show that, the reductions in overhead that consists of header and tailer is 25% to 44%. The system level investigations in a multi-user environment with a total of 3 relays in the cell show an average end-to-end goodput gain of 13%.