Constrained range beacon for consensual service registration and delivery in a delimited area

A communications system is described wherein consensual push of services from radio beacons (30, 32, 33) to a user's portable device (14) is enabled. The consent process comprises a user registering the portable device (14) at a registration beacon (30) to consent to data delivery from other relevant beacons (32, 33) in a network. The registration beacon (30) has a broadcast range which is constrained within, and highlighted to a user as, an indicated interaction zone (16). The range is preferably constrained and highlighted using electromagnetic shielding (18), or by using a directional antenna, or a combination of both. In use, the user must position their portable device (14) within the indicated interaction zone (16) to register for service delivery.