Transmitter location for maximum coverage and constructive–destructive interference management

Covering location models consider a demand ‘covered’ if there is at least one facility sited within a preset threshold distance. If more than one facility satisfies this criterion, it is implicitly assumed that one of these facilities – usually the closest – will serve the customer, while the remaining ones will have no relation to the demand. However, there are cases in which this multiple coverage has either synergetic or undesired effects. In digital television broadcast networks using Single Frequency Network transmissions, if a customer receives transmissions from more than one transmitter, the strongest transmitter is the main signal source, while the second and following transmitters can either contribute to a good reception or act as sources of interference, depending on the technology and their relative locations. In this case, facilities should be located so as to avoid overlapping coverage if there is interference, or enhancing overlapping coverage if signals are combined constructively. We propose models that are solved using a commercial software, that address this problem. One of these models is used to compare different alternatives of network design for a region in Chile, and to find the best coverage situations.