Patent ID: 8725080

Claim:
A method of initiating transmission by a mobile radio subscriber unit in a trunked radio system, the trunked radio system comprising an infrastructure and mobile radio subscriber units, the method comprising a first mobile radio subscriber unit: receiving data from at least one other radio subscriber unit, the data for each of the least one other radio subscriber units comprising identification data, and data about transmission and/or reception activity by each of the least one other radio subscriber units; determining the received signal power of signals from the least one other radio subscriber units; determining whether transmission by the first mobile radio subscriber unit would provide interference above a first pre-determined level, and/or reception by the first mobile radio subscriber unit would be subject to interference above a second pre-determined level; and delaying transmission, when transmission by the first mobile radio subscriber unit would provide interference above the first pre-determined level, or reception by the first mobile radio subscriber unit would be subject to interference above the second pre-determined level.