This Small Business Innovation Research (SBIR) Phase II project will demonstrate the ability of an adaptive antenna system ? a radio with an antenna that changes its radiation pattern to provide coverage where it is needed ? to automatically optimize coverage. Harsh RF environments, for example those with shifting reflective surfaces such as shipping container yards, make it hard to set up reliable communication even when there is only one radio. When several radios must work together to provide coverage in an extended area, it is extremely difficult and time-consuming to manually tailor the radiation pattern of each antenna so that every portion of the area receives adequate signal and the radios do not interfere with each other. Through a combination of innovative pattern computation algorithms and active sensor feedback, the system resulting from this project will automatically tailor coverage to meet these goals. The system will not just be able to set up the initial coverage of an area, it will also continually monitor the quality of the coverage and automatically adjust to changes in the system or the environment that may affect the quality of that coverage.
The broader impact/commercial potential of this project is decreased deployment costs and substantially increased reliability. In the short run, the system will be built with a WiFi platform for use in the maritime ports market as a more reliable communication system to run their mission critical scheduling application. The deployment savings result from not only a quicker and more reliable initial setup but also from automated adjustments to coverage as environmental factors change ? including such radical changes as the failure of one radio. Because the system is agnostic to the frequency and the protocol used by the radio, it is not limited to WiFi deployments. The project will demonstrate this by creating and operating a prototype WiMAX version of the adaptive antenna system. In the long term, this adaptive antenna technology offers significant benefits to any large scale radio deployment. For example, as providers roll out the next generation of cellular, cell sizes will shrink significantly which will substantially increase the deployment cost. An adaptive antenna system offers not only the promise of reducing these costs but also adding increased connection reliability to these next generation systems.
This Small Business Innovation Research (SBIR) project resulted in an innovative algorithm that creates an interlocking set of custom antenna patterns which optimizes coverage for a multi access point site, created a commercial 802.11 client and associated monitoring software that allows customers monitor the RF performance of their network, and opened up the potential for more efficient use of the RF spectrum in areas such as cellular. The optimization algorithm, which Fidelity Comtech calls the "PPS" ("Probability of Packet Success") algorithm, defines an entirely new optimization criterion: maximize the probability that a packet transmitted from anywhere in the desired coverage area will be successfully received. The algorithm computes this probability based on existing antenna patterns and the EIRP of the mobile client for a site with access points at given locations. It then iterates in a structured way over varying pattern sets until the result converges to an optimum solution. Fidelity has used this algorithm to create enhanced antenna patterns for almost a half dozen commercial ports resulting in significantly improved coverage over the omni patterns that are typically used. Fidelity Comtech has also repurposed the sensor and software used during this project to develop and validate the PPS algorithm into commercial products. The sensor was re-engineered into an 802.11 client called an "eCone" consisting of a high power 802.11 radio and a GPS packaged in a rugged, weatherproof case designed to be mounted on the top of a vehicle. The software was rewritten to become "NetWatch", a monitoring program that leverages the location and status reporting capabilities of the eCone to provide the customer with a visual map displaying the RF performance of the network. In the long run, the adaptive antenna technology developed by Fidelity Comtech for the maritime ports market can be applied to any wireless communication system using multiple base stations. In particular, the technology is an especially good fit for cellular communication. In order to accommodate the ever increasing demand for bandwidth, wireless companies are, among other things, increasing the number of cells by shrinking their size. This process exacerbates the problem of self-interference. The adaptive antenna technology developed as part of this project can be a significant part of the solution to this problem.
