Delay optimization using Knapsack algorithm for multimedia traffic over MANETs

• Established mathematical relationship among packet size, buffer size and delay.
• Optimized router buffer capability by forwarding packets in correct order.
• Minimize the delay by maximizing the in-order packets.
• High conversion rate of out-of-order packets into in-order within the buffer.
• We report throughput improvement over existing approaches.

Multimedia transmission over Mobile Ad-hoc Networks (MANETs) is crucial to many applications. However, MANETs possess several challenges including transmitting large size packets, minimizing delay, loss-tolerant and buffer size estimation. For effective multimedia transmission, delay should be minimized and packets should be received in the defined order. The existing standards such as 802.11b and 802.11e perform well in wireless networks, but exhibit poor response in MANETs for multimedia traffic, especially in multi-hop networks. In this paper, we first establish the dependency of delay on buffer size and packet size, and then present a delay optimization approach for multimedia traffic in MANETs. We use Knapsack algorithm for buffer management to maximize the in-order packets and minimize the out-of-order packets simultaneously. Our approach exploits the buffer internals and dynamically adjusts the buffer usage so that a node transmits the packets in the desired order to its successive nodes. Careful estimation of packet size and buffer size helps in minimizing the delay, improving the capability of receiving packets in the correct order and reducing out-of-order packets in the buffer at intermediate nodes. Our approach also controls the loss of multimedia data packets during transmission. We validate our approach with real-world examples using network simulator.