Patent ID: 7515874

Claim:
A terminal for a short range wireless mobile communication system, comprising a directional signal wave converter; and a controller configured to determine an optimum beam and to adjust said directional signal-wave converter to transmit/receive an information-carrying signal wave by said optimum beam; the controller further configured to detect whether a distance between the terminal and a further terminal falls short of a predefined distance value; the controller further configured to, when said distance falls short of said predefined distance value, determine a beamwidth so that the beamwidth is increased to a fixed beamwidth value, determine a set of allowed beam directions to comprise a unique beam direction, and determine the optimum beam as a beam having said fixed beamwidth value and said unique beam direction value; and the controller configured to, when said distance does not fall short of said predefined distance value, determine a beamwidth according to a function which increases when the distance decreases, determine a set of allowed beam directions based on said beamwidth to comprise a plural number of allowed beam directions, said number decreasing when the beamwidth increases, and determine the optimum beam as a beam for which a reported quality is the highest according to a beam-tracking algorithm wherein, sequentially for each particular beam direction among said set of allowed beam directions, a burst is transmitted by a beam having said particular beam direction and said determined beamwidth and in response thereof a report including an indication of the quality of the beam is received from the further terminal.