Patent ID: 8644266

Claim:
A method of operating a radio communication apparatus for use with a communication channel divided into a plurality of time slots, and at least one radio station for receiving signals transmitted by the radio communication apparatus, the method comprising: transmitting data in a first subset of the time slots; refraining from transmitting data in a second subset of the timeslots; transmitting a control signal in each of the time slots, wherein the control signal in the first subset of time slots comprises at least one bit constituting a power control command and a portion which is a predetermined signal; and for at least some of the second time slots, and relative to the first time slots, adjusting between control signal formats, at least some of the time when the data is not transmitted during the second subset of the timeslots, by increasing the proportion of the bits of the control signal which constitutes a power control command and reducing the proportion of the bits of the control signal which constitutes a predetermined signal portion and reducing the energy of the control signal at least by reducing the energy of the predetermined signal portion by a factor in proportion to the reduction of the number of bits constituting the predetermined signal portion determining, at the radio station, that the radio communication apparatus has no data to transmit in a particular time slot or group of time slots, and/or that the radio communication apparatus has no permission to transmit data; and in response to said determining, optionally transmitting an indication to the radio communication apparatus.