Method for performing USTS handover and USTS mode switching in a mobile communication system
First Claim
1. A handover controlling method in a radio network controller (RNC) connected to a first Node B and a second Node B in a mobile communication system where an Uplink Synchronous Transmission Scheme (USTS) service occurs between the first Node B and a user equipment (UE) within a cell of the first Node B and the UE hands over when the UE is located in a handover area across cell areas of the first Node B and the second Node B, the cell area of the second Node B being adjacent to the cell area of the first Node B, the method comprising the steps of:
- determining if the handover for the UE is possible;
transmitting handover information to the second Node B if the handover is possible, the handover information including the scrambling code of the UE, a scrambling code time offset representing the time difference between the start point of the scrambling code used for data communication between the UE and the first Node B and the start point of a uplink data frame, and a channelization code for a transmission channel of the data; and
transmitting a command to the UE through the first Node B, requesting the UE to hand over to the second Node B if the RNC receives a response message for the handover information from the second Node B indicating that the handover is possible.
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Accused Products
Abstract
Disclosed is a handover controlling method in an RNC connected to a first Node B and a second Node B in a mobile communication system where a USTS service occurs between the first Node B and a UE within a cell of the first Node B and the UE hands over when the UE is located in a handover area across the cell areas of the first Node B and the second Node B adjacent to the first Node B. The method comprises determining whether the handover for the UE is possible or not; transmitting handover information to the second Node B if the handover is possible; and transmitting a command to the UE through the first Node B, requesting the UE to hand over to the second Node B if the UE receives a response message indicating that the handover is possible from the second Node B.
94 Citations
34 Claims
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1. A handover controlling method in a radio network controller (RNC) connected to a first Node B and a second Node B in a mobile communication system where an Uplink Synchronous Transmission Scheme (USTS) service occurs between the first Node B and a user equipment (UE) within a cell of the first Node B and the UE hands over when the UE is located in a handover area across cell areas of the first Node B and the second Node B, the cell area of the second Node B being adjacent to the cell area of the first Node B, the method comprising the steps of:
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determining if the handover for the UE is possible;
transmitting handover information to the second Node B if the handover is possible, the handover information including the scrambling code of the UE, a scrambling code time offset representing the time difference between the start point of the scrambling code used for data communication between the UE and the first Node B and the start point of a uplink data frame, and a channelization code for a transmission channel of the data; and
transmitting a command to the UE through the first Node B, requesting the UE to hand over to the second Node B if the RNC receives a response message for the handover information from the second Node B indicating that the handover is possible. - View Dependent Claims (2, 3, 4, 5)
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6. A handover controlling method in a Node B in a mobile communication system where a Uplink Synchronous Transmission Scheme (USTS) service occurs between a first Node B and a user equipment (UE) within a cell of the first Node B and the UE hands over when the UE is located in a handover area across cell areas of the first Node B and a second Node B, the cell area of the second Node B being adjacent to the cell area of first Node B, the method comprising the steps of:
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receiving handover information indicating that the UE is receiving the USTS service from an radio network controller (RNC), the handover information including a channelization code for a data transmission channel of the UE, a scrambling code used for the data communication, and a scrambling code time offset representing the time difference between the start point of the scrambling code and the start point of a uplink data frame; and
transmitting a response message for the handover information to the RNC and assigning a handover channel according to the channelization code; and
performing scrambling code synchronization by setting the start point of the uplink data frame relative to the scrambling code start point according to the scrambling code time offset. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21)
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14. A method of converting a non-Uplink Synchronous Transmission Scheme (USTS) mode to a USTS mode in a communication between a Node B connected to a radio network controller (RNC) and a user equipment (UE) within a cell area of the Node B, comprising the steps of:
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measuring by the Node B a round trip time (RTT) indicating the distance between the Node B and the UE;
transmitting the measured RTT from the Node B to the RNC;
transmitting from the RNC to the UE a scrambling code and a channelization code for use in the UE, and information representing a variance of the start point of a downlink data frame to be transmitted to the UE so that the downlink data frame starts at a position apart from a reference time point of the Node B by a multiple of predetermined number of chips; and
transmitting the scrambling code and the channelization code from the RNC to the Node B.
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22. A method of converting from a non- Uplink Synchronous Transmission Scheme (USTS) mode to a USTS mode in a communication between a Node B connected to an radio network controller (RNC) and a user equipment (UE) within a cell area of the Node B, comprising the steps of:
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receiving a message including information representing a variance of the start point of an uplink data frame received from the UE to make the uplink data frame start at a position apart from a reference time point of the Node B by a multiple of predetermined number of chips, and a channelization code and a scrambling code of a transmission channel on which the uplink data is transmitted from the RNC;
calculating a scrambling code time offset if it is determined that the USTS mode conversion is possible for the UE, and transmitting a response message including the scrambling code time offset to the RNC; and
assigning the received channelization code and scrambling code to the communication and determining the start points of the uplink data frame and the scrambling code according to the scrambling code time offset, and transitioning to the USTS mode. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29)
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30. A method of converting a non-Uplink Synchronous Transmission Scheme (USTS) mode to a USTS mode in a communication between a Node B connected to an radio network controller (RNC) and a user equipment (UE) within a cell area of the Node B, comprising the steps of:
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receiving a predetermined uplink signal from the UE, measuring a propagation delay of the received predetermined uplink signal, and transmitting the propagation delay measurement and a USTS mode conversion request to the RNC by the Node B;
determining an additional delay based on the propagation delay measurement and transmitting the determined additional delay to the UE by the RNC; and
starting to transmit an uplink data transmission signal by the UE after the propagation delay and the additional delay from reception of a downlink data transmission channel signal. - View Dependent Claims (31, 32, 33, 34)
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Specification