Controlling communications in a multi-carrier wireless communication system

Abstract

A method of controlling communication between a first network node and a second network node in a multi-carrier wireless communications system, network nodes and a computer program product are disclosed. The method of controlling communication between a first network node and a second network node in a multicarrier wireless communications system in which a predetermined set of a plurality of carriers are utilized to support communication between the first network node and the second network node, the predetermined set of the plurality of carriers comprising a primary carrier and at least one secondary carrier, comprises the steps of: determining an occurrence of an event requiring a change in the primary carrier; indicating to a third network node that a physical layer instruction is to be transmitted between said first network node and the second network node; and transmitting a physical layer instruction between the first network node and the second network node, the physical layer instruction encoding reselection information to cause the second network node to select a different carrier from the plurality of carriers as a new primary carrier. By sending the instruction using the layer one or physical layer, the speed at which the instruction can be transmitted between the network nodes is vastly increased, which enables fast switching to occur, thereby preventing a loss of communications between the network nodes. By indicating to a third network node that a physical layer instruction is to be transmitted between the first network node and the second network node, maintenance of synchronization is simplified and unpredictable network behavior is minimized.