Patent ID: 8738033

Claim:
A method of determining whether a small cell basestation in a communications network has changed position, wherein the network operates with separate downlink and uplink frequencies, the method comprising: at a first time, interrupting transmissions from the small cell basestation on said downlink frequencies and detecting, at the small cell basestation, signals transmitted on said downlink frequencies by a first plurality of neighbouring basestations whose transmissions can be detected at the first time, wherein the transmitted signals include cell identities of the first plurality of neighbouring basestations from which the transmitted signals can be detected; forming a first list of the cell identities of the first plurality of neighbouring basestations; at a second time, interrupting transmissions from the small cell basestation on said downlink frequencies and detecting, at the small cell basestation, signals transmitted on said downlink frequencies by a second plurality of neighbouring basestations whose transmissions can be detected at the second time, wherein the transmitted signals include cell identities of the second plurality of neighbouring basestations from which the transmitted signals can be detected; forming a second list of the cell identities of the second plurality of neighbouring basestations; determining whether the small cell basestation has changed position based on the first and second lists of cell identities; and responsive to a determination that the small cell basestation has changed position, sending an alarm signal to an operator of the communications network.