A GPS Dog Fence is one of the easiest methods to create a proper area for a dog without having to build a traditional fence. Unlike a regular fence, it employs GPS to determine the borders within which a dog may roam free. This function can be readily handled with the use of the Halo program. The Halo Collar and the program work together to create a virtual fence for your property or yard. The procedure gives the option to determine and set a border depending on the geometry