Patent ID: 6999751

Claim:
A method in a base station of detecting cloned communication units, the method comprising: receiving, responsive to a page message, a first response message and a second response message; determining whether a first identification filed corresponding to the first response message is equivalent to a second identification field corresponding to the second response message; when the first identification filed is equivalent to the second identification field, assessing whether one of a first message content and a first message property corresponding to the first response message is not correlated, respectively, with one of a second message content and a second message property corresponding to the second response message; and when the one of the first message content and the first message proverty is not correlated, respectively, with the one of the second message content and the second message property, deciding that one of the first response message and the second response message corresponds to a cloned communication unit, wherein the assessing whether the first message property is not correlated with the second message property further comprising assessing whether a first arrival time of the first response message is not correlated with a second arrival time of the second response message, and wherein the first and the second arrival time are compared to provide a relative arrival time and when the relative arrival time satisfies a threshold determining that the first message property is not correlated with the second message property.