Information dissemination over low-bandwidth links

In today's Internet age, web-based applications are an extremely logical way to disseminate, update, and visualize information. Our modern wired infrastructure and high-speed wireless access points make it possible to access high-bandwidth demanding applications from nearly everywhere. However, in places where infrastructure does not exist, and where information needs to be disseminated over areas beyond which common wireless standards can reach, it is difficult to implement an efficient and inexpensive web-based application to handle the dissemination and visualization of such data. This paper presents a novel approach to creating a web-based application in such an environment. The AX.25 protocol is commonly found on the amateur radio bands. While this has the ability to be sent thousands of miles in an ad-hoc environment, its high latency and low bandwidth make it impractical, if not impossible, to establish TCP/IP links to send and receive HTTP-based data. However, this protocol is well suited for an environment that lacks a communication infrastructure. Therefore, instead of trying to send web traffic, one solution is to send only the required traffic by having two applications that synchronize their back-end data. The MySQL Database Management System software is an excellent choice for the database since it is open source and has a replication engine designed to work over slow dial-up links. In addition, Linux is the operating system of choice since it natively supports the AX.25 protocol as part of the protocol stack making the integration of MySQL and AX.25 straightforward. With a MySQL back-end, a standard web-based application can be made on either side of the AX.25 link and locally distributed using 802.11 wireless or ethernet. This system was shown to be effective at the 2010 Boy Scout Jamboree at West Point, where a front-end website was built using jQuery and AJAX. This gave the organizers of the event an intuitive drag-and-drop interface to assign and track troops which checked-in miles away from their camp sites, located over hilly terrain. The website was updated asynchronously allowing data to be shared in near-real time. This combination of AX.25 and modern web techniques using AJAX can potentially be used for many other applications. The interface has also been tested with a Ruby on Rails blog application which maintained perfect database synchronization as well. Based on these examples, we believe that many off the shelf web applications that use MySQL can easily be set up for use over AX.25.