Method for propagation delay control
AssigneeTelefonaktiebolaget L M Ericsson (publ)
InventorsJohan Karoly Peter Galyas, Stefan Wilhelm Jung
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Abstract
A method for maintaining synchronization between a base transceiver station (BTS) and an interworking function (IWF) within a cellular communications network is disclosed. The method utilizes a synchronization procedure between the IWF and the BTS that makes the IWF aware of propagation delays between the IWF and BTS. The IWF utilizes this information to adapt to the delays such that the correct sequence is unpacked uplink when obtained from the base transceiver station. The IWF also uses synchronization data to control transmissions from the IWF to the BTS such that frame numbers and timeslots are received at the BTS in the correct sequence.
Claims29
A method for synchronizing transmission of a data stream between a wireline network node and a base transceiver station, the base transceiver station connected with an air interface within a cellular communications system, the method comprising the steps of:
- a) transmitting from the base transceiver station to the wireline network node uplink synchronization frames containing uplink synchronization data;
- b) transmitting from the wireline network node to the transceiver station downlink synchronization frames containing downlink synchronization data in response to receipt of the uplink synchronization frames;
- c) determining from the uplink synchronization data, an unpacking sequence for time slots of the data stream transmitted over independently routable subchannels of a wireline transport network between the wireline network node and the base transceiver station;
- and
- d) unpacking the data stream according to the determined unpacking sequence such that the time slots are unpacked in increasing sequence number order.
A method for synchronizing transmission of a data stream between a wireline network node and a base transceiver station, the base transceiver station connected with an air interface within a cellular communications system, the method comprising the steps of:
- a) transmitting from the base transceiver station to the wireline network node uplink synchronization frames comprising V.110 frames containing uplink synchronization data, the uplink synchronization frames each containing an adjusted frame number uplink and an uplink sequence number;
- b) transmitting from the wireline network node to the base transceiver station, in response to receipt of the uplink synchronization frames, downlink synchronization frames comprising V.110 frames containing downlink synchronization data, the downlink synchronization frames each containing a downlink sequence number;
- c) comparing a phase of frames from independently routable subchannels of a wireline transport network between the wireline network node and the base transceiver station with the same adjusted frame number uplink and uplink sequence number to determine an unpacking sequence for the data stream transmitted over the independently routable subchannels;
- and
- d) unpacking the transmitted data stream according to the determined unpacking sequence such that the data stream is unpacked in increasing sequence number order.
A method for synchronizing transmission of a data stream between a first node and a second node connected within an interface of a wireline transport network within a cellular communications system, comprising the steps of:
- initializing a synchronization request from the second node;
- transmitting synchronization frames to determine a corresponding timing delay for independently routable subchannels of the wireline transport network between the first node and the second node in response to the synchronization request;
- determining the corresponding timing delay of the independently routable subchannels of the wireline transport network between the first and the second node;
- and
- controlling the data stream at the first node in response to the determined timing delay.
Dependencies are inferred from the claim text.