Methods and arrangements are provided for use in communications systems that allow for secure communication sessions to be conducted over a communications link between at least two nodes (12', 16'). An entity authentication process is conducted using a cryptography key (70). During the authentication process, a ciphering offset (COF) value (50) is generated. Each node (12', 16') stores the COF value (50) and uses the COF value (50) to generate subsequent ciphering keys (70) that are employed to encrypt data transmitted between the nodes (12', 16'). As such, there is a logical relationship between the latest entity authentication process and subsequently generated ciphering keys (70). This increases security and can be used to reduce overhead processing/delays associated with repeating the link or entity authentication process. The methods and arrangements can be employed to enhance security in any communications system, including a mobile telecommunications system, such as, for example, a global system for mobile (GSM) communications system.

Methods and arrangements for secure linking of entity authentication and ciphering key generation

In an inter-station synchronization method establishing frame synchronization for a radio interval between radio base stations via a mobile station in a cellular mobile communication system constituted by a plurality of zones, a time alignment value corresponding to a mobile station which is in communication with a reference station is measured. An adjustment station receives a transmission signal from the mobile station which is in communication with the reference station, and a radio frame phase difference representing an offset between the received signal and a home intra-station radio frame synchronization signal is measured. A radio frame phase control value is obtained on the basis of a radio frame phase difference measured by the adjustment station and the time alignment value measured by the reference station. The phase of the radio frame synchronization signal of the adjustment station is adjusted in accordance with the obtained radio frame phase control value to be matched the phase with a phase of a radio frame synchronization signal in the reference station.

Inter-station synchronization method

A login permission method improving network security and efficiently performing a login process is disclosed. In a host-based network, information required for outside login is previously registered with the host-based network. When an outside login request is received from a terminal through the communications line, it is determined whether user's login information is validated based on the registered information required for outside login. Only when the user's login information is validated, the terminal is permitted to log in to the host-based network from outside.

Login permission with improved security

In a time divisional multiple access type mobile communication system including a plurality of base stations, each of the base stations receiving broadcast signals from the other base stations, and determining a broadcast transmission timing in synchronization with and different from timings of the received broadcast signals. Then, a broadcast signal is transmitted at the broadcast transmission timing.

Mobile communication system capable of establishing frame syncronization among base stations

Described herein is a method of providing synchronization between a plurality of base stations ( 300 ) in a telecommunications system which comprises providing a random access channel in each cell ( 320 ). A local base station ( 300 ) uses the random access channel in the local cell to transmit a synchronization signal to neighboring base stations. For each base station, the time differences between received synchronization signals from neighboring base stations and the local synchronization signal are calculated. Each set of time differences is either used to autonomously synchronize the local base station or is centralized in a radio network controller and a set of corrections distributed from the RNC to the base stations.

Mobile telecommunications systems

PURPOSE: To eliminate the need for an exclusive transmitter-receiver for establishing synchronization between base stations and to establish the synchronization between base stations even when radio communication between base stations is difficult by establishing the synchronization between base stations via a mobile equipment. CONSTITUTION: Suppose that a base station A is a radio base station having a master clock, a base station B is conventional radio base station not having a master clock and the mobile station is in communication with the base station A. When the mobile station receives a signal sent from the base station A, a clock in a reception signal is recovered, the timing of a transmission data is adjusted and the signal is sent synchronously with the clock in the reception signal. In the case of the receipt of the signal sent from the said mobile equipment, the base station recovers the clock of the reception signal and the result is used as the clock of a transmission signal. Thus, the synchronization between the base stations A, B is established. COPYRIGHT: (C)1990,JPO&Japio

Synchronization establishment method between base stations

PURPOSE:To enable a mobile station to be shared and to prevent illegal use by specifying a authentication confirmation signal and a authentication reply signal of a mobile set and a subscriber with a random number and a secret key and starting the operation when both the signals are coincident. CONSTITUTION:A random number generating circuit 31 generates at first a random number R for an authentication request in a base station and transmits the number to a mobile station. A mobile set 30 enters the random number R and secret keys Ks, Kp of the mobile set and subscriber to a signal conversion circuit 33 to obtain an authentication reply and a communication ciphering key Ke1 and transmits the authentication reply to the base station. The base station inputs the random number R and secret keys Ks, Kp to a signal conversion circuit 32 to obtain an authentication reply and a communication ciphering key Ke2. A comparator circuit 34 compares a bit pattern of the authentication reply received from the mobile station with a bit pattern of the authentication reply generated in the base station, and enables the authentication of the mobile set when they are coincident and disables the recognition in other cases. That is, then the authentication of the mobile set and the subscriber authentication are implemented simultaneously by one authentication procedure to share the mobile station by plural subscribers without degradation in the throughput.

Shinji Kamibayashi

Papers

Synchronization establishment method between base stations

Authentication method in digital mobile communication