Evaluations of Wireless Multihop Network Incorporating Intermittent Periodic Transmit and Packet Forwarding Path Reservation

Intermittent Periodic Transmit (IPT forwarding) is known as a packet forwarding scheme that achieves highly efficient packet relays in wireless multihop networks. In the method, a source node sends source packets intermittently and periodically with some transmit period, by which co-transmission space of forwarding packets, that is defined as space between multihop nodes in packet transmission, can be controlled in accordance with the given transmit period. If the transmit period is greater than a certain limit, packet collisions due to interference are eliminated and thus packet forwarding is maximized in its efficiency. However, the IPT forwarding needs elaborations on network topology for a given node layout because the principle of the scheme relies on string topology of node layout. This paper proposes a technique to enable the IPT forwarding in any network topologies. In the proposed scheme, a source node reserves a packet forwarding path to make the relay nodes on the path devote themselves to forward the packets originated by the source node. In addition, neighboring nodes close to the forwarding path are made to set their NAV (Network Allocation Vector) to prevent them from giving interference to the nodes on the reserved path. The proposed scheme can be combined with a conventional routing algorithm such as tree type ones or mesh type ones. Simulation results ensure that the combination of the IPT forwarding with the proposed path reservation achieves higher throughput and lower average packet delay compared with a conventional packet forwarding method.