Patent ID: 6308078
Filing Date: 2001-10-23
Classification: H04B

Abstract:
A method for evaluating transmission time delays at transmission paths in a radio telecommunication system between a central interface unit and a plurality of radio access units operatively connected to said central interface unit, wherein said radio access units transmit radio signals to and receive radio signals from adjacent radio access units relative to their own time base, wherein said transmission time delays are evaluated from time differences between a time of transmission of a radio signal by a radio access unit relative to the time base of said radio access unit and a time of reception of said radio signal by an adjacent radio access unit relative to the time base of said adjacent radio access unit, said time bases being controlled by said central interface unit and lagging said transmission time delays, said method comprises the steps of:a) transmitting a first radio signal from a first of said plurality of radio access units at a first time relative to the time base of said first radio access unit;b) receiving said first radio signal by a second of said plurality of radio access units at a second time relative to the time base of said second radio access unit;c) transmitting a second radio signal from said second radio access unit at a third time relative to the time base of said second radio access unit;d) receiving said second radio signal by said first radio access unit at a fourth time relative to the time base of said first radio access unit; ande) calculating from said first, second, third and fourth time a relative transmission time delay between the transmission paths from said central control unit to each of said first and second radio access units.