We have had two commercial cotton farms in Mississippi under complete wireless local area network coverage for about 3 years in a current demonstration project for precision agriculture applications. The farm in eastern Mississippi has about 1600 acres of contiguous farmland with gently rolling land. We used Alvarion BreezeAccess II equipment with an omni antenna at thebase station to communicate to three repeater station located at the edges of the farm. Directional panel antennas connected to BreezeAccess II 2.4 GHz radios which then went to Breezecomm radios connected to 120 degree sector antennas which broadcast into the farm to the equipment in the fields. THe farm equipment was equipped with Breezecom radios attached to omni antennas. All of these radios are frequency hopping spread spectrum radios. These have a range of about 2.5 miles talking from sector antennas to omnis. Wifi will onlu have a range of 1500 feet talking to omnis. An omni antenna is the only cost effective practical device to put on a tractor, combine or truck. The other reason we chose Alvarion is that their radios automatically handle mobility. That is, they can automatically hand over communcation from sector to sector as boudaries are crossed with loosing connection or packets of data. This system has a user data rate of 2 Mbps. The base station has a Starband satellite link to the Internet. We have also used DirecWay satellite links.
The other farm is located in the Mississippi Dellta and is set up similarly with the exception being that the communication from the base station to the 9 repeater stations is handled using the Waverider 900 MHz radios. This farm consists of over 12000 acrs of cotton farmland separated by various tree lines and is roughly oval shaped with the major axis being 12 miles from side to side with the farm headquarters situated in the middle. We needed the 900 MHz radios to penetrate the trre lines to reach the Breezecom repeaters with 120 degree sector antennas to provide field coverage. THe siganl from the base station reaches almost 10 miles so the entire farm is covered by the base station. However, you must use yagi antenna precisely aimed to get reception. Thus, the use of the repeater station using Alvarion Breezecom as before. I can sen you a copy of the research paper we published if this is of further interest to you. James Dr. James M. McKinion USDA-ARS Genetics and Precision Agriculture Res. Unit P. O. Box 5367 Mississippi State, MS 39762 Ph: 662-320-7449 FAX: 662-320-7528 Email: [EMAIL PROTECTED] -- WISPA Wireless List: wireless@wispa.org Subscribe/Unsubscribe: http://lists.wispa.org/mailman/listinfo/wireless Archives: http://lists.wispa.org/pipermail/wireless/
