Abstract: The invention relates to a method of limiting the size of synchronization messages between a first synchronization device and a second synchronization device. The first device specifies a maximum message size for synchronization messages to be sent to the first device and transmits information on the maximum message size to the second device. The second device transmits to the first device one or more synchronization messages which are equal to or smaller than the maximum message size of the first device.

Abstract: A method for performing authentication in a communication system comprising an authentication server, and a user profile store storing user profiles for users of the communication system, the method comprising: transmitting from the authentication server to the user profile store a request for the user profile of a user; receiving at the authentication server a response to the request; determining whether the response is indicative of an error; and if the response is indicative of an error, transmitting from the authentication server to the user profile store a message of a type such as to trigger the user profile store to perform a location update procedure in respect of the user.

Abstract: A receiver comprising means for receiving a first plurality of signals at different frequencies at substantially the same time; and means for comparing a wanted signal at a first frequency with at least one other signal at a frequency similar to that of said wanted signal to provide a measure of interference provided by said at least one other signal.

Abstract: A method and apparatus for producing a ringing tone in a communication device, such as a mobile phone, an electronic organizer or a personal digital assistant, to signal an event in the communication device. The method includes the steps of generating a sequence of musical notes in a random fashion within a range of pitch and duration for defining the musical notes, modifying the sequence of musical notes based on a set of modification rules in order to produce a modified sequence, and repeating the modified sequence for forming a motif. More than one motif can be produced and stored in a computer-readable medium at a user's initiation of the communication device to allow the user to choose one of the motives as a ringing tone for signaling a different event. The user can delete one or more motives stored in the computer-readable medium and generate new ones, if desired.