METHOD AND SYSTEM FOR ADJUSTING UPLINK TRANSMISSION TIMING FOR LONG TERM EVOLUTION HANDOVER
First Claim
1. A wireless communication system comprising:
- at least one user equipment (UE); and
an evolved universal terrestrial radio access network (E-UTRAN) comprising;
a source cell/Node-B which sends a handover command message to the UE when the E-UTRAN determines it is time to perform a handover; and
a target cell/Node-B, wherein the UE adjusts uplink transmission timing when sending an initial transmission to the target cell/Node-B immediately after handover based on information included in the command handover message.
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Accused Products
Abstract
A method and system for adjusting uplink transmission timing when sending an initial transmission to a target cell/Node-B of an evolved universal terrestrial radio access network (E-UTRAN) immediately after handover from a source cell/Node-B of the E-UTRAN. In one embodiment, a user equipment (UE) autonomously computes and applies a timing advance (TA) value based on the current source cell/Node-B timing value, cell/Node-B beacon channel reference signal measurements and knowledge of the relative time difference, (if any), between the source and target cells/Node-Bs. In another embodiment, the UE sends a scheduling request message or real data packets with the computed TA value applied to the uplink transmission timing to the E-UTRAN via pre-allocated non-contention based uplink radio resources. In an alternate embodiment, the UE sends a scheduling request message with the new computed TA value applied to the UL transmission timing to an E-UTRAN via a synchronous random access channel (RACH).
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Citations
51 Claims
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1. A wireless communication system comprising:
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at least one user equipment (UE); and
an evolved universal terrestrial radio access network (E-UTRAN) comprising;
a source cell/Node-B which sends a handover command message to the UE when the E-UTRAN determines it is time to perform a handover; and
a target cell/Node-B, wherein the UE adjusts uplink transmission timing when sending an initial transmission to the target cell/Node-B immediately after handover based on information included in the command handover message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A long term evolution (LTE) handover method which is implemented in a wireless communication system including at least one user equipment (UE) and an evolved universal terrestrial radio access network (E-UTRAN) including a source cell/evolved Node-B (eNB) and a target cell/eNB, the method comprising:
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the source cell/eNB sending a handover command message to the UE when the E-UTRAN determines it is time to perform a handover; and
the UE adjusting uplink transmission timing when sending an initial transmission to the target cell/eNB immediately after handover based on information included in the command handover message. - View Dependent Claims (26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47)
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48. A long term evolution (LTE) handover method which is implemented in a wireless communication system including at least one wireless transmit/receive unit (WTRU) and an evolved universal terrestrial radio access network (E-UTRAN) including a source cell/evolved Node-B (eNB) and a target cell/eNB, the method comprising:
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the source cell/eNB sending a handover command message to the WTRU when the E-UTRAN determines it is time to perform a handover;
the WTRU autonomously computing an initial timing advance value;
the WTRU sending a scheduling request message with the computed first timing advance value through a synchronous random access channel (RACH) to the E-UTRAN; and
the E-UTRAN computing a refined time advance value that is more accurate than the initial timing advance value based on information in the scheduling request message. - View Dependent Claims (49)
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50. A wireless communication system comprising:
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at least one wireless transmit/receive unit (WTRU); and
an evolved universal terrestrial radio access network (E-UTRAN) including a source cell/evolved Node-B (eNB) and a target cell/eNB, wherein the source cell/eNB sends a handover command message to the WTRU when the E-UTRAN determines it is time to perform a handover, the WTRU autonomously computes an initial timing advance value, the WTRU sends a scheduling request message with the computed first timing advance value through a synchronous random access channel (RACH) to the E-UTRAN, and the E-UTRAN computes a refined time advance value that is more accurate than the initial timing advance value based on information in the scheduling request message. - View Dependent Claims (51)
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Specification