If co-location of the GPS receiver and the data download computer (if one is required) is not feasible, a communication link between the receiver and computer will be needed. The user must determine which method of communications will provide the most cost effective results. A mixed mode of communications may be the only viable solution. Each of the following methods should be examined in order to determine an effective data transfer route: short-haul modems, phone modems, radio modems, cell modems, and satellite links.