DETERMINING PROPAGATING AND CLEAR FREQUENCY IN WIRELESS DATA COMMUNICATIONS NETWORK

A two-way communications system that provides ubiquitous wireless data communication services, such as throughout the continental United States, by using a network of only a few, widely distributed radio base station (RBS) sites and the existing paging network infrastructure. The paging network infrastructure is used as an outbound link to request data from the remote field units. The outbound page message indicates a time and HF frequency at which the RBSs can expect to receive inbound data from the field units. A network hub or mission operation center (MOC) determines a radio frequency which is expected to be propagating and clear at the time that a particular field unit is to use the frequency as an inbound link. The MOC then issues the request for data to the field unit using an existing inexpensive wireless system such as the paging network infrastructure. The field units make use of paging receivers, and an HF transmitter to report remote data such as a geoposition or other sensor data when requested to do so.