Abstract: Disclosed is a method of operation for use in a radio communications system comprising a cellular network of base stations and mobile units linked to the base stations. The method comprises detecting that a base station has become isolated from the system, wherein the isolated base station has lost at least one link to other base stations but is still in radio communication with its mobile units and changing an output power level of said isolated base station relative to an output power level of one or more selected co-channel base stations of neighboring cells of the cellular system, whereby the range of communications provided by said isolated base station is changed to a different finite value relative to that provided by the said co-channel base stations.

Abstract: A plurality of encryption keys is generated, and each encryption key is associated with one geographical area of a plurality of geographical areas. Each encryption key is forwarded to one or more base stations in the geographical area associated with the encryption key. At least one of the plurality of geographical areas that is adjacent to a first geographical area is determined, yielding one or more adjacent geographical areas, and an encryption key for at least one of the one or more adjacent geographical areas is forwarded to at least one base station covering the first geographical area.

Abstract: A plurality of infrastructure system devices other than a mobile station is divided into a plurality of pools. An intrakey is utilized to encrypt messages passed between infrastructure system devices in the same pool, and an interkey is utilized to encrypt messages passed between infrastructure system devices of different pools.

Abstract: A first infrastructure system device other than a mobile station generates an encryption key and encrypts the encryption key with a first intrakey associated with a first zone that includes a second infrastructure system device other than a mobile station, yielding a first encrypted encryption key. The first intrakey is used only by infrastructure system devices other than a mobile station for encrypting at least the encryption key prior to transport within the first zone. The first infrastructure system device forwards the first encrypted encryption key to the second infrastructure system device.

Abstract: A first infrastructure system device other than a mobile station generates key material and forwards the key material to a second infrastructure system device other than a mobile station. A determination is made as to whether a mobile station for which the key material is directed is active on the system, and if so the key material is forwarded to a base station where the mobile station is active. The base station forwards the key material to the mobile station.

Abstract: A home location register stores key material related to mobile stations associated with the home location register. A first visited location register associated with a first site in a first zone stores key material related to a first mobile station of the mobile stations associated with the home location register. When the first mobile station roams to a second site in a second zone associated with a second visited location register, the key material related to the first mobile station is encrypted with an interkey, yielding encrypted key material, wherein the interkey is used only by infrastructure system devices other than a mobile station for encrypting at least the key material for transport between at least the first and second zones. The encrypted key material is forwarded to the second visited location register.

Abstract: A wireless, ad-hoc or private communications network (100) comprising nodes (102, 112, 120, 130, 140), forming with other elements of the network a switching and management infrastructure /SwMI/, and subscribers, wherein each of said nodes (102, 112, 120, 130, 140) has a Visitor Location Register /VLR/ (108, 118, 126, 136, 142), and at least a part of said nodes (102, 112, 120, 130) are provided with Home Location Registers /HLRs/ (106, 116, 124, 134) and at least a part of said nodes (102, 120) with said HLRs (106, 124) are provided with gateways (110, 128), wherein in said network (100) every node (102, 112, 120, 130) with an HLR (106, 116, 124, 134) is assigned to a node (102, 120) having a gateway (110, 128) and said SwMI directs calls to and from a subscriber of said network (100) to an external network via said assigned node with a gateway.

Abstract: A method includes receiving an authentication request from a mobile station (401) and determining whether to forward the request to an authentication agent. When it is determined to forward the request, the request is forwarded to the authentication agent (107). A random number and a random seed are received from the authentication agent (107). The random number and the random seed are forwarded to the mobile station (401). A response to the random number and the random seed from the mobile station (401) is received and forwarded to the authentication agent (107). The authentication agent (107) compares the response with an expected response. When the authentication agent (107) authenticates the mobile station (401), a derived cipher key is received from the authentication agent (107).

Abstract: A method includes receiving an authentication request from a mobile station (401) and determining whether to forward the request to an authentication agent. When it is determined to forward the request, the request is forwarded to the authentication agent (107). A random number and a random seed are received from the authentication agent (107). The random number and the random seed are forwarded to the mobile station (401). A response to the random number and the random seed from the mobile station (401) is received and forwarded to the authentication agent (107). The authentication agent (107) compares the response with an expected response. When the authentication agent (107) authenticates the mobile station (401), a derived cipher key is received from the authentication agent (107).

Abstract: A method of controlling location information of subscribers (210, 212, 222) in a wireless, ad-hoc communications network (200). The network (200) comprises a plurality of nodes (204, 216, 226), wherein at least portion of said nodes are provided with Home Location Registers (HLRs) (206, 218, 228) and each of said nodes (204, 216, 226) has a Visitor Location Register (VLR) (208, 220, 230). When an operation of a first node (216) is to be reconfigured at least a part of records from a first HLR (218) assigned to said first node (216) are transferred to at least one of the other nodes (226) of the network (200).

Abstract: A method of operation for use in a radio communications system comprising a cellular netword of base stations and mobile units linked to such base stations, the method comprising the following steps, with respect to any base station operable to provide direct radio communication with mobile units linked thereto: (i) detecting that a base station has become isolated from the system, and, in consequence, (ii) changing relative to one another the output power level of said isolated base station and the output power level of one or more selected neighbouring co-channel base stations of the cellular system, whereby the isolated base station continues to communicate with the mobile stations served by it under conditions which are adjusted to deal with the isolation condition.

Abstract: A method of transmitting call information includes transmitting (201), within a first cell (105), call information relating to a call taking place within the first cell (105) and transmitting (203), within a second cell (103), the call information relating to the call taking place within the first cell (105). Alternatively, the method includes transmitting (201), within a first cell (105), call information relating to a first call taking place within the first cell (105) and transmitting (205), within the first cell (105), call information relating to a second call taking place within the second cell (103).

Abstract: A method of operation of a communications system, having first (10) and second communications units (12) communicating frame divided information via a relay device (11). The second communications unit (12) transmits a timing signal (step 106) to the first communications unit (10), containing timing information of received timing signals from the first communications unit(10). The first communications unit (10) calculates a timing offset (step 114) for the combined timing delay for transmissions to and from the second communications unit via the relay device and transmits the timing offset (step 116) to the second communications unit. The second communications unit (12) adjusts its timing (step 122) according to the received timing offset. A communications system includes a frame number offset indicator (27) for performing timing synchronisation between the communications units.