Patent ID: 8780884

Claim:
A method for synchronizing a plurality of mobile radio devices, comprising: transmitting a downlink synchronization signal in a shared downlink synchronization channel a plurality of mobile radio devices, wherein the downlink synchronization signal is common to the plurality of mobile radio devices; and receiving a plurality of uplink synchronization signals via a plurality of dedicated uplink synchronization channels, wherein each uplink synchronization signal indicates that a respective mobile radio device has synchronized to the shared downlink synchronization channel; wherein the method is carried out during a handover procedure from a first mobile radio communication system to a second mobile radio communication system; wherein the downlink synchronization signal is received by the plurality of mobile radio devices; and wherein each mobile radio device of the plurality of mobile radio devices transmits a respective uplink synchronization signal via a respective dedicated uplink synchronization channel of the plurality of dedicated uplink synchronization channels; and wherein the first mobile radio communication system is a Global Systems for Mobile Communications mobile radio communication system or a Universal Mobile Telecommunications System and wherein the second mobile radio communication system is a Universal Mobile Telecommunications System Long Term Evolution mobile radio communication system; or wherein the first mobile radio communication system is a Universal Mobile Telecommunications System Long Term Evolution mobile radio communication system and wherein the second mobile radio communication system is a Global Systems for Mobile Communications mobile radio communication system or a Universal Mobile Telecommunications System.