IP Packet Forwarding Mechanism in Multi-Hop Tactical Wireless Networks

Abstract

Today's modern tactical operations are going towards the concept of Network Centric Warfare. In such military operations, tactical wireless networks require high demands for robustness, responsiveness, reliability, availability and security. One of the key requirements of the tactical user expectation is to efficiently utilize the available bandwidth. IP packet routing in the tactical wireless networks which are connected via IP radios consume more system bandwidth in order to maintain the up-to-date information. Complex routing protocols have to be implemented in the radio as embedded software modules in order to exchange the IP routing information. This will consume the system bandwidth thereby throughput will be reduced. Moreover, hop by hop routing method will reconstruct the entire IP packet by changing the destination MAC address in every hop thereby packet processing time will be increased. In this paper, we have proposed two simple and efficient IP packet forwarding schemes for multi-hop tactical wireless networks which are connected via radios. Both schemes make use additional parameters such as unique radio identifier and associated IP Address/MAC address table during the topology discovery process using the link state routing algorithm. After successful topology discovery, each wireless node in the network will get to know the entire network topology in terms of a table containing the radio connectivity list and each radios associated LAN IP address/MAC address. This network topology table will be used in during the packet forward decision making process. The associated IP/MAC address to node Id mapping table will be used to find the destination radio Id from the incoming IP packet. The forwarding radio nodes will examine only the radio header portion of the received IP packet instead of analyzing & reconstructing the entire IP packet thereby packet processing time will be reduced at each intermediate wireless node. There by packet processing time will be reduced. The proposed approach also supports for forwarding of broadcast and multicast IP packets to enable group communication among the IP networks which are connected via the IP radios. Overhead for both of the proposed approaches are very minimal and consume less bandwidth.