Method of synchronizing broadcast streams in multiple soft handoff sectors
AssigneeTelefonaktiebolaget LM Ercisson (publ)
InventorsErik Colban, Srinivasan Balasubramanian, Irfan Khan
Life of this patent
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Abstract
Transmission of broadcast streams in multiple sectors is synchronized based on time stamps or sequence numbers in data packets received at the base station. The base stations use the time stamps to calculate a frame transmission start time and start position for the data packets. The base station monitors the packet latency of data within its buffer based on the time stamp in the data packets and initiates a resynchronization procedure if the packet latency exceeds predetermined bounds.
Claims34
A method of synchronizing transmission of a broadcast stream to a mobile station from multiple base stations during a soft handoff, the method comprising:
- receiving, at a base station, a plurality of data packets stamped with time stamps;
- computing a frame transmission start time of a starting frame for a first data packet and one or more subsequent data packets based on the time stamp in said first data packet;
- synchronizing transmission of the data packet from said base station to a mobile station based on the computed frame transmission start time for said data packets;
- computing a packet latency for each data packet based on said time stamps contained said data packets;
- and
- re-synchronizing if the computed packet latency is outside a predetermined range, including re-synchronizing if the computed packet latency is less than a predetermined minimum latency.
A base station controller comprising one or more control circuits configured to:
- receive data packets stamped with time stamps;
- compute a frame transmission start time of a starting frame for each data packet based on the time stamp in a first data packet and one or more subsequent data packets;
- synchronize transmission of the data packets with other base stations based on the computed frame transmission start time for each data packet;
- compute a packet latency for said data packet based on the time stamps contained in said data packets;
- and
- re-synchronize if the computed packet latency is outside a predetermined range, including re-synchronizing if the packet latency is less than the predetermined minimum latency.
A method of synchronizing transmission of a broadcast stream to a mobile station from multiple base stations during a soft handoff, the method comprising:
- receiving a plurality of data packets at a base station, said received data packets including a first data packet stamped with a time stamp and one or more subsequent data packets;
- computing a transmission time for said first data packet based on said time stamp in said first data packet;
- computing a transmission time for each subsequent data packet and any carry-over bits from a preceding data packet;
- adding the computed transmission time for each subsequent data packet to the frame transmission start time of the preceding data packet to get a frame transmission start time or said subsequent data packet;
- and
- synchronizing transmission of the data packet from said base station to a mobile station based on the computed frame transmission start time for each data packet.
A base station controller comprising one or more control circuits configured to:
- receive a plurality of data packets at a base station, said received data packets including a first data packet stamped with a time stamp and one or more subsequent data packets;
- compute a transmission time for said first data packet based on said time stamp in said first data packet;
- compute a transmission time for each subsequent data packet plus any carry-over bits from a preceding data packet;
- add the computed transmission time for each subsequent data packet to the frame transmission start time of the preceding data packet to get a frame transmission start time or said subsequent data packet;
- and
- synchronize transmission of the data packet from said base station to a mobile station based on the computed frame transmission start time for each data packet.
Dependencies are inferred from the claim text.