Wireless Multi-hop Network Geocast Multicast Protocol Studies

The feature of wireless Multi-hop networks is no base stations, no central control. The Geocast protocols (geography location-based multicast protocols) which are wireless multicast routing protocols based on directional delivery, can reduce the data redundancy and the delay of end to end. So the Geocast protocols are widely absorbed attention by related industry. The exiting Geocast protocols can forward the packet to the destination region with forwarding region. In order to decrease the data redundancy, they use forward region to suppress to forward data packets of most nodes. When the networks is dense, the exiting Geocast protocols have the shortcoming of the large data redundancy and the seriously channel competition leading to the high rate of data dropped, more frequent of data packet forwarding and the longer of the delay of end to end. the paper will propose two protocols based GeoGRID protocol.In order to decrease the delay and the data redundancy, the paper will propose two protocols based GeoGRID protocol. The proposed protocols design the appropriate length of the grid and the strategy of building the network grid. Then we design the gateway selection algorithm in forwarding region and in destination region. In forwarding region, the node which is nearest to the center of the grid is selected the gateway. In the destination region, it proposes the method of judging the edge grid and the algorithm of selecting more than a gateway in the edge grid. At last, it analyzes and designs the process of the node switching the grid (including the grid process of interaction before and after the movement). The proposed protocols can manage the network nodes with grid switching.The paper will propose the two kinds of new protocol based the GeoGRID protocol: the GeoGRID-LBM protocol and A-GeoGRID (Advanced GeoGRID) protocol based two hops information. GeoGRID-LBM protocol has the advantage of the GeoGRID protocol and the LBM protocol. It forwards the packet to the neighbor gateway which is nearest to the central of destination region. The algorithm can forward packet with direction, decrease the delay. To a large extent, it can reduce the data redundancy to forward the packet with the gateway and the rate of data collision. A-GeoGRID protocol uses the two hops information to forward the packet to the neighbor gateway whose neighbor is nearest to the central of the destination region. This method can forward the packet with stronger direction, decrease the probability of channel competition and going back, reduce the delay,reduce the data redundancy, improve the stability of the proposed protocols in sparse networks. At last, the paper will simulate the performance of the proposed protocols with OPNET. The results show that the proposed protocols obviously reduce the data redundancy, the rate of data collision and the delay of end to end.