A method operating a cellular communication system comprising a plurality of neighbouring small cells, each of said plurality of neighbouring small cells supporting communications between a wireless communication unit and a core network through an access controller, the method comprising: assigning a unique area code from a group of unique area codes to each neighbouring small cell, storing a unique area code associated with the access controller, and receiving, at a first of said neighbouring small cells, a registration request from a wireless communication unit, said request including an identity of the wireless communication unit and an area code of a last visited cell, wherein the method is characterised by: comparing the area code of the last visited cell with the area code of the first cell, and if they are different and belong to said group of unique area codes, generating an acceptance message including the unique area code of the first cell, and forwarding said acceptance message to the wireless communication unit without forwarding the registration request to the core network, otherwise, replacing the unique area code of the first cell with the area code associated with the access controller in the registration request, forwarding the request to the core network, replacing the unique area code associated with the access controller with the unique area code of the first cell in a registration acceptance message received from the core network and forwarding the registration acceptance message to the wireless communication unit. assigning a unique area code from a group of unique area codes to each neighbouring small cell, storing a unique area code associated with the access controller, and receiving, at a first of said neighbouring small cells, a registration request from a wireless communication unit, said request including an identity of the wireless communication unit and an area code of a last visited cell, wherein the method is characterised by: comparing the area code of the last visited cell with the area code of the first cell, and if they are different and belong to said group of unique area codes, generating an acceptance message including the unique area code of the first cell, and forwarding said acceptance message to the wireless communication unit without forwarding the registration request to the core network, otherwise, replacing the unique area code of the first cell with the area code associated with the access controller in the registration request, forwarding the request to the core network, replacing the unique area code associated with the access controller with the unique area code of the first cell in a registration acceptance message received from the core network and forwarding the registration acceptance message to the wireless communication unit. comparing the area code of the last visited cell with the area code of the first cell, and if they are different and belong to said group of unique area codes, generating an acceptance message including the unique area code of the first cell, and forwarding said acceptance message to the wireless communication unit without forwarding the registration request to the core network, otherwise, replacing the unique area code of the first cell with the area code associated with the access controller in the registration request, forwarding the request to the core network, replacing the unique area code associated with the access controller with the unique area code of the first cell in a registration acceptance message received from the core network and forwarding the registration acceptance message to the wireless communication unit.