Custom Wireless Networking over Standard Physical Layers, 10-R9753Printer Friendly Version
Inclusive Dates: 10/01/07 Current
Background - Wireless networking for personal and business computing has become ubiquitous in the past several years because of standards such as IEEE 802.11 (WiFi). Many companies have invested large amounts of capital to develop electronics to implement the standard, and chip sets are commercially available that implement 802.11. This has been driven by the size of the market, and the work that has been put into the development of the standard.
Some military and space applications have a need for two-way wireless networks in environments in which 802.11 and other standards will not suffice. For instance, wireless links that must traverse very long distances require a protocol that will not be affected by large propagation delays. Developing new standard protocols from the ground up for these environments is very costly, and delays the insertion of wireless networks into these application areas.
Approach - The goal of this research is to develop a technique for leveraging the investment in standards, such as 802.11, to develop highly customized wireless protocols for applications with vastly different signal environments than that for which the standard was developed. The objective is to develop a demonstration system that leverages 802.11 electronics in a target environment with long distances (up to 150 nautical miles) and high closing speed between the radios (high Doppler effect). The approach is to utilize the physical layer electronics developed to support the 802.11 standard, but replace the collision avoidance-based Media Access (MAC) and link layer with a custom, scheduled protocol with deterministic behavior.
Accomplishments - The project has developed a novel dynamic time division multiple access (DTDMA) algorithm to create a deterministic protocol that can work with standard 802.11 physical layer electronics to create a wireless link that can operate over long distances. The protocol has been successfully simulated. A laboratory demonstration system is being developed that uses standard 802.11 electronics in tandem with an embedded computer to implement the custom protocol.