Transition mechanism for energy efficient mobile overlay network

A communications network including radio stations, a cluster of radio stations in the communications network being operable to switch between a first state, in which a first number of radio stations is active and a second state in which a second, different number of radio stations is active, in which the second state is intended to provide the same geographic coverage as the first state but a different capacity, wherein

• the radio stations are controlled to carry out the transition between states using transmission parameter adjustment, wherein the transmission parameter adjustment takes place in a plurality of radio stations and is co-ordinated in time for these radio stations,
• wherein the control allows transmission parameter adjustment to take place in one or more steps, the control including initially determining a number of steps in the transition according to a number of user equipment handovers expected to be produced by the transition, and
• wherein the control includes initially determining a size of steps according to the number of user equipment handovers expected to be produced by the transition.

A radio station in a cluster of radio stations in a communications network, the cluster being operable to switch between a first state, in which a first number of radio stations is active and a second state in which a second, different number of radio stations is active, in which the second state is intended to provide the same geographic coverage as the first state but a different capacity, wherein

• the radio station includes control functionality to carry out the transition between states using transmission parameter adjustment, with timing specified so that the transmission parameter adjustment takes place in co-ordination with other radio stations in the cluster, and
• wherein the control allows transmission parameter adjustment to take place in one or more steps, the control including initially determining a size of the one or more steps and a number of steps in the transition according to a number of user equipment handovers expected to be produced by the transition.

A coordinating entity operable to control a transition in a cluster of radio stations of a communications network, by coordinating a switch between a first state, in which a first number of radio stations is active and a second state in which a second, different number of radio stations is active, in which the second state is intended to provide the same geographic coverage as the first state but a different capacity;

• wherein
• the coordinating entity includes functionality to instruct the radio stations to carry out the transition between states using transmission parameter adjustment, wherein the instructed transmission parameter adjustment takes place in a plurality of radio stations and is co-ordinated in time for these radio stations;
• the coordinating entity initially determining a number of one or more steps of transmission parameter adjustment and a size of the one or more steps in transition according to a number of user equipment handovers expected to be produced by the transition and then instructing the transmission parameter adjustment to take place in the number and size of steps.