SBIR-STTR Award

Originally aimed at offsetting the expense and time associated with installing Ethernet office networks, wireless LAN products are finding their way into more demanding Industrial and Military environments and applications.Unlike office or residential applications, the Military/Industrial wireless application scenarios require levels of performance and reliability beyond what is currently available. The challenges facing the next generation of industrial strength wireless LAN products can be summarized as follows:Extreme Environmental Stresses Sustainable operation in harsh physical environments~~~ Predictable connectivity in various friend and foe jamming scenarios~~~ Connectivity in open, closed, and connected spacesApplication Based Requirements~~~ On-demand multi-link thruput~~~ Guarantee user access~~~ Seamless roaming between nodesThis research will investigate a next generation approach (3G) to providing concurrent high-speed multi-user wireless accessibility within a non-cooperative electromagnetic environment.This research will examine the multi-access capabilities of code division multiple access (CDMA) with the robustness of orthogonal frequency division multiplexing to overcome channel impairments such as multipath and jamming.Using available COTS IEEE 802.11 2.4 GHz components and communication systems modeling applications Phase I output will focus on establishing a set of implementation strategies and technological techniques for implementing a short range jam resistance link-agile multi-access CDMA/OFDM transceiver.This technology has specific and immediate industrial and commercial application, these include:1. Enhanced spectrum utilization in the VHF to 1 GHz spectrum. The 150 MHz - 1 GHz band plays a major role in business, commercial and national infrastructure communications. Primarily used for narrowband voice and data applications the FCC is actively seeking modulation and coding techniques, which substantially increase channel capacity, and effective data throughput without affecting legacy narrowband services.2. Providing low-cost multi-access high-density voice and data services for semi- urban and rural business and residential subscribers. More than thirty percent of U.S. citizens are without reasonably priced Internet access and nearly 10 percent are lacking reliable voice service. Worldwide it is estimated that the unfulfilled demand is for 45-50 million network connections per year. 3. Next generation of in-building high-speed multi-user LAN systems. Productized this technology would provide 100 MHz + wireless office LAN connectivity.

Keywords:
Cdma, Ofdm, Multi-Access, Fcc, Modulation, Coding

Phase II of this project will provide a prototype high-capacity frequency agile shipboard wireless LAN system. The system is intended to provide uninterrupted network connectivity in the event primary or secondary hardwired WAN and/or LAN transport systems are compromised. The proposed system will integrated concepts and knowledge gained in Phase I to produce a hybridize wireless LAN node capable of concurrently establishing and managing three independent high bit rate (5-15 Mbps) full duplex IP base wireless links in a dense shipboard RF environment. Fundamental to successful implementation is the ability to search and find moderately wide and relatively free spectral transmission and transmission widows over a wide controlled bandwidth. Utilizing discovery and classification algorithms investigated in Phase I together with fourth generation COTS wireless LAN integrated circuit technology, the system will be able to provide sub-second alternative back-up service to a wide range of C4I and HM&E systems. Initiated in Phase I, ongoing inter-compartment and inter-deck measurement exercises will be extended to additional vessel classes. This effort will form the basis of an ongoing propagation profiling and cataloging effort, which will be immensely useful in fleet deployment. On-air system verification will consist of installing and independently testing 10 to 15 wireless LAN nodes in a variety of nominal and fault induced operational scenarios.

Keywords:
FREQUENCY AGILE,WIRELESS LAN,SPECTRAL WINDOWING, FREQUENCY HOPPERS