Mobile communication method and radio base station

• US 8,699,454 B2
• Filed: 02/06/2009
• Issued: 04/15/2014
• Est. Priority Date: 02/08/2008
• Status: Expired due to Fees

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Hapsari, Wuri Andarmawanti, Motegi, Masayuki, Uchiyama, Tadashi
• Primary Examiner(s): Hamza, Faruk
• Assistant Examiner(s): LO, DIANE LEE
• Application Number:
  US12/866,856
• Publication Number:
  US 20110013593A1
• Time in Patent Office: 1,894 Days
• Field of Search: None
• US Class Current: 370/331
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 36/02 Buffering or recovering information during reselection ; Modification of the traffic flow during hand-off
• CPC Class Codes: H04W 36/08 Reselecting an access point

Abstract

A mobile communication method according to the present invention includes: the steps of: (A) transferring, from a first radio base station (S-eNB) to an upper level node (S-GW), consecutive uplink data received from a mobile station (UE) with their sequence numbers being consecutive, by use of a resource allocated by the upper level node (S-GW), when the first radio base station (S-eNB) determines that the mobile station (UE) is to perform a handover; (B) transmitting, from the first radio base station (S-eNB) to the upper level node (S-GW) transfer completion notification data after the transfer of the consecutive uplink data to the upper level node (S-GW) is completed; and (C) releasing, at the upper level node (S-GW), the resource when receiving the transfer completion notification data.

Claims

1. A mobile communication method comprising the steps of:

(A) transferring, from a first radio base station to a second radio base station, the downlink data which are among the downlink data received from an upper level node and whose transmission to a mobile station is not completed yet, when the first radio base station determines that the mobile station is to perform a handover from a cell controlled by the first radio base station to a cell controlled by the second radio base station; and

(B) performing, at the second radio base station, sequence control between downlink data received from the upper level node and the downlink data received from the first radio base station by use of transfer completion notification data, when receiving the transfer completion notification data,

wherein in the step (A), when a receiving intermediate storage at the first radio base station has become empty and when receiving no downlink data from the upper level node for a predetermined period of time, the first radio base station transmits the transfer completion notification data to the second radio base station, and

wherein the transfer completion notification data contains no downlink data.

2. The mobile communication method according to claim 1, further comprising the step of:

(C) transmitting, from the first radio base station to the second radio base station, the transfer completion notification data, after the transfer of the downlink data from the first radio base station to the second radio base station is completed, the transfer completion notification data indicating the completion of the transfer of the downlink data.

3. The mobile communication method according to claim 2, wherein

in the step (A), when receiving a switch completion notice from the upper level node, the first radio base station transmits the transfer completion notification data to the second radio base station, the switch completion notice notifying that transfer of downlink data to the second radio base station is started.

4. The mobile communication method according to claim 1, further comprising a step of:

(D) transmitting, from the first radio base station to the second radio base station, the transfer completion notification data received from the upper level node.

5. A radio base station comprising:

a downlink data transfer unit configured to transfer downlink data to a different radio base station when it is determined that a mobile station is to perform a handover from a cell controlled by the radio base station to a cell controlled by the different radio base station, the downlink data being downlink data which are among the downlink data received from an upper level node and whose transmission to the mobile station is not completed yet; and

a transfer completion notification data transmitter unit configured to transmit transfer completion notification data to the different radio base station after the transfer of the downlink data from the radio base station to the different radio base station is completed, the transfer completion notification data indicating the completion of the transfer of the downlink data,

wherein the different radio base station is configured to perform sequence control between downlink data received from the upper level node and the downlink data received from the radio base station by use of transfer completion notification data, when the transfer completion notification data is received, and

wherein the transfer completion notification data transmitter unit is configured to transmit the transfer completion notification data to the different radio base station, when a receiving intermediate storage at the radio base station has become empty and when no downlink data is received from the upper level node for a predetermined period of time, and

wherein the transfer completion notification data contains no downlink data.

6. The radio base station according to claim 5, wherein

the transfer completion notification data transmitter unit is configured to transmit the transfer completion notification data to the different radio base station, when a switch completion notice is received from the upper level node, the switch completion notice notifying that transfer of downlink data to the different radio base station is started.