GENERATION OF KEY STREAMS IN WIRELESS COMMUNICATION SYSTEMS

摘要

Security key stream generation in a communication apparatus. The method includes using a count parameter and a bearer parameter as input, value of said count parameter being incremented as security key streams are generated and value of the count parameter having a finite maximum value; detecting value of the count parameter reaching a predetermined value (31); and responsive to the detecting, changing value of the bearer parameter into a previously used bearer parameter value (32); wherein the previously used bearer parameter value is not currently in use in said communication apparatus; and resetting value of the count parameter to a value below the maximum value (33).