WO2015117549A1 - 用于删除无线链路控制服务数据单元的方法和基站 - Google Patents

用于删除无线链路控制服务数据单元的方法和基站 Download PDF

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Publication number
WO2015117549A1
WO2015117549A1 PCT/CN2015/072213 CN2015072213W WO2015117549A1 WO 2015117549 A1 WO2015117549 A1 WO 2015117549A1 CN 2015072213 W CN2015072213 W CN 2015072213W WO 2015117549 A1 WO2015117549 A1 WO 2015117549A1
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Prior art keywords
base station
sdu
rlc
timer
expired
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PCT/CN2015/072213
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English (en)
French (fr)
Inventor
肖芳英
刘仁茂
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夏普株式会社
肖芳英
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Application filed by 夏普株式会社, 肖芳英 filed Critical 夏普株式会社
Priority to US15/116,746 priority Critical patent/US20160352643A1/en
Publication of WO2015117549A1 publication Critical patent/WO2015117549A1/zh

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H04L47/32—Flow control; Congestion control by discarding or delaying data units, e.g. packets or frames
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L47/00—Traffic control in data switching networks
    • H04L47/10—Flow control; Congestion control
    • H04L47/28—Flow control; Congestion control in relation to timing considerations

Definitions

  • the present invention relates to mobile communications, and in particular to a method of deleting a radio link control service data unit and a corresponding base station.
  • the Layer 2 User Plane Protocol Stack of the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) system consists of three sublayers, from high to low: Packet Data Convergence Protocol (PDCP) layer, wireless chain. Radio Link Control (RLC) layer and Media Access Control layer.
  • PDCP Packet Data Convergence Protocol
  • RLC Radio Link Control
  • SDU Service Data Unit
  • PDU Protocol Data Unit
  • the RLC layer receives packets from the PDCP. These packets are PDCP PDUs for the PDCP layer but RLC SDUs for the RLC layer.
  • the process is reversed, with each layer sending an SDU to the upper layer and the upper layer receiving it as a PDU.
  • the PDCP SDU is compressed, encrypted, and attached to the PDCP header by the IP header to be mapped into a PDCP PDU.
  • the RLC SDU is partitioned/concatenated according to the size specified by the MAC layer and added to the RLC PDU after adding the RLC header.
  • the PDCP SDU is identified by a PDCP sequence number, the PDCP SDU has the same sequence number as the corresponding PDCP PDU and the RLC SDU, and the RLC PDU is identified by the RLC sequence number.
  • each radio bearer has one PDCP entity and one RLC entity.
  • Each base station also known as a NodeB or evolved NodeB (eNB)
  • each user equipment has one MAC entity.
  • the storage time (also called the discard time) of the PDCP SDU in the base station and the user equipment is controlled by a discard timer.
  • the PDCP layer receives the PDCP SDU from the upper layer, the associated deletion timer is started, and when the deletion timer expires, the PDCP SDU associated with the deletion timer is deleted, and is located at the same base station or user equipment.
  • the RLC layer in the middle sends an indication.
  • the RLC layer After receiving the indication, the RLC layer deletes the RLC SDU if the corresponding RLC SDU has not been mapped to the RLC PDU.
  • the user equipment may be a user terminal, a user node, a mobile terminal or a tablet.
  • the primary base station is responsible for maintaining the radio resource management measurement configuration of the user equipment and requesting the secondary base station to provide additional resources (also called serving cells) to the user equipment based on the received measurement report or traffic status or bearer type.
  • additional resources also called serving cells
  • the secondary base station configures the serving cell for the user equipment or rejects the request due to insufficient resources.
  • two user plane architectures 1A and 3C, are determined as standardized options for the dual connectivity deployment mode.
  • the option 3C shown in FIG. 1 has the following features: (1) the primary base station communicates with the service gateway through the S1-U interface; (2) the bearer is separated in the primary base station; and (3) for the separated bearer, at the primary base station and the secondary base station There are corresponding RLC entities in it.
  • the RLC entity located at the secondary base station interacts with the upper layer (ie, the PDCP entity located at the primary base station) through an Xn interface, which includes the X2 interface.
  • the delay control of the RLC SDU can be implemented by the delay control of the PDCP SDU, that is, when the PDCP SDU is deleted due to the expiration of the deletion timer, If the corresponding RLC SDU has not been mapped to the RLC PDU, the RLC SDU is deleted.
  • the process of deleting the RLC SDU in the above non-dual-connection deployment scheme is implemented internally by the base station, so no standardization is required.
  • the PDCP entity corresponding to the split bearer and one of the RLC entities are located in the primary base station, and the other RLC entity is located in the secondary base station.
  • the existing non-dual-connection deployment solution cannot solve the problem of RLC SDU delay control in the secondary base station in the dual-connection deployment scheme, so that the expired RLC SDUs are stored or transmitted in the secondary base station for a long time, which will result in storage space of the secondary base station. Waste and waste of wireless transmission resources.
  • a mechanism is needed to delete the RLC SDU received from the primary base station in the secondary base station, wherein any part of the RLC SDU has not been mapped to the RLC PDU and the corresponding PDCP SDU has been deleted due to expiration. .
  • the present invention provides a method of deleting a radio link control service data unit and a corresponding base station.
  • a method performed in a secondary base station for deleting a Radio Link Control "RLC” service data unit “SDU” received from a primary base station comprising the following Step: initiate an RLC deletion timer associated with the RLC SDU received from the primary base station; if the RLC deletion timer has not expired and any portion of the RLC SDU is mapped to a Radio Link Control "RLC” protocol data unit PDU", deleting the RLC deletion timer; and deleting the RLC SDU if the RLC deletion timer expires.
  • the RLC deletion timer is set by a request message sent by the primary base station for adding additional resources to the user equipment or by an inter-node radio resource control message; and the RLC deletion timer satisfies the following Condition: The deletion time of the associated RLC SDU is at the same time or after the expiration time of the packet data convergence protocol "PDCP" service data unit "SDU" corresponding to the primary base station.
  • PDCP packet data convergence protocol
  • a method performed in a primary base station for deleting a Radio Link Control "RLC” Service Data Unit “SDU” from a primary base station received in a secondary base station comprising The following steps: if the deletion timer associated with the packet data aggregation protocol "PDCP” service data unit "SDU” expires, deleting the PDCP SDU; and if the PDCP PDU corresponding to the deleted PDCP SDU has been sent to the secondary
  • the base station sends an indication message for deleting the RLC SDU corresponding to the PDCP PDU to the secondary base station, where any part of the corresponding RLC SDU has not been mapped to the radio link control "RLC” protocol data unit "PDU” ".
  • the method further comprises deleting the PDCP PDU if the packet data convergence protocol "PDCP" protocol data unit "PDU" mapped by the deleted PDCP SDU is locally saved.
  • the method further includes: saving a sequence number of the expired PDCP SDU; if the number of the saved expired PDCP SDUs reaches a preset number, sending the location to the secondary base station The indication message is sent; or, if the first timer expires, the indication message is sent to the secondary base station, where the first timer is used to determine a maximum time interval for the primary base station to send the indication message to the secondary base station.
  • the method further includes: saving a sequence number of the expired PDCP SDU; and transmitting the indication message to the secondary base station if the second timer expires, wherein the second timer is used And determining a time interval for the primary base station to send the indication message to the secondary base station.
  • the method further includes: saving a sequence number of the expired PDCP SDU; if the third timer expires, sending the indication message to the secondary base station, where the third timer is used to determine the primary a time interval at which the base station sends the indication message to the secondary base station; wherein the indication message includes a minimum sequence number and a bitmap of the expired PDCP SDU, and the minimum sequence number of the expired PDCP SDU is a third timing The minimum sequence number of the expired PDCP SDU sent by the secondary base station during the timing period of the device.
  • the method further includes: saving the sequence number of the expired PDCP SDU; if the difference between the maximum and minimum sequence numbers of the expired PDCP SDU is greater than or equal to the bitmap length, sending to the secondary base station The indication message; or, if the fourth timer expires, sending the indication message to the secondary base station, where the fourth timer is used to determine a maximum time interval for the primary base station to send the indication message to the secondary base station;
  • the indication message includes a minimum sequence number and a bitmap of the expired PDCP SDU, and the maximum sequence number of the expired PDCP SDU is the PDCP SDU of the primary base station that has expired in the timing period of the fourth timer.
  • the maximum sequence number, the minimum sequence number of the expired PDCP SDU is the minimum sequence number of the expired PDCP SDU sent by the secondary base station in the timing period of the fourth timer.
  • the first timer, the second timer, the third timer, or the fourth timer is configured by a radio resource control configuration/reconfiguration message.
  • a secondary base station capable of deleting a radio link control "RLC" service data unit "SDU” received from a primary base station, the secondary base station comprising: a timer starting unit configured to Starting an RLC deletion timer associated with the RLC SDU received from the primary base station; a first deletion unit configured to: if the RLC deletion timer has not expired and any part of the RLC SDU is mapped to a wireless link Controlling the "RLC" protocol data unit "PDU", deleting the RLC deletion timer; and the second deleting unit is configured to delete the RLC SDU if the RLC deletion timer expires.
  • RLC radio link control
  • the RLC deletion timer is set by a request message sent by the primary base station for adding additional resources to the user equipment or by an inter-node radio resource control message. And the RLC deletion timer satisfies the condition that the deletion time of the associated RLC SDU is at the same time or after the expiration time of the packet data convergence protocol "PDCP" service data unit "SDU" corresponding in the primary base station.
  • PDCP packet data convergence protocol
  • a primary base station capable of deleting a radio link control "RLC" service data unit "SDU" received from a primary base station, the primary base station comprising: a first deletion unit Configuring, if the deletion timer associated with the packet data aggregation protocol "PDCP" service data unit "SDU” expires, deleting the PDCP SDU; and the transmitting unit configured to: if the deleted PDCP SDU Corresponding PDCP PDUs have been sent to the secondary base station, and an indication message for deleting the RLC SDU corresponding to the PDCP PDU is sent to the secondary base station, and any part of the corresponding RLC SDU has not been mapped to the wireless link.
  • the primary base station further includes: a second deleting unit, configured to: if the packet data convergence protocol "PDCP” protocol data unit "PDU" mapped by the deleted PDCP SDU is locally saved, delete the Describe the PDCP PDU.
  • a second deleting unit configured to: if the packet data convergence protocol "PDCP" protocol data unit "PDU" mapped by the deleted PDCP SDU is locally saved, delete the Describe the PDCP PDU.
  • the primary base station further includes: a storage unit configured to save a sequence number of the expired PDCP SDU; wherein the sending unit is further configured to: if the saved expired PDCP SDU Sending the indication message to the secondary base station when the number of sequence numbers reaches a preset number; or sending the indication message to the secondary base station if the first timer expires, the first timer is used to determine The maximum time interval for the primary base station to send the indication message to the secondary base station.
  • the primary base station further includes: a storage unit configured to save a sequence number of the expired PDCP SDU; wherein the sending unit is further configured to: if the second timer expires, Sending the indication message to the secondary base station, where the second timer is used to determine a time interval at which the primary base station sends the indication message to the secondary base station.
  • the primary base station further includes: a storage unit configured to save a sequence number of the expired PDCP SDU; wherein the sending unit is further configured to: if the third timer expires, Sending the indication message to the secondary base station, where the third timer is used to determine a time interval for the primary base station to send the indication message to the secondary base station; the indication message includes a minimum sequence number and a bitmap length of the expired PDCP SDU And bitmap, the expired PDCP SDU
  • the minimum sequence number is the minimum sequence number of the expired PDCP SDU transmitted by the secondary base station during the timing period of the third timer.
  • the primary base station further includes: a storage unit configured to save a sequence number of the expired PDCP SDU; wherein the sending unit is further configured to: if the PDCP SDU has expired Sending the indication message to the secondary base station if the difference between the minimum sequence number and the minimum sequence number is greater than or equal to the bitmap length; or sending the indication message to the secondary base station if the fourth timer expires, the fourth timer is used to Determining a maximum time interval for the primary base station to send the indication message to the secondary base station; where the indication message includes a minimum sequence number and a bitmap of the expired PDCP SDU, and the maximum sequence number of the expired PDCP SDU is The maximum sequence number of the PDCP SDU that has expired in the primary base station in the time period of the fourth timer, and the minimum sequence number of the expired PDCP SDU is the time that has been sent by the secondary base station in the time period of the fourth timer The minimum serial number of the PDCP SDU for the period.
  • the first timer, the second timer, the third timer, or the fourth timer is configured by a radio resource control configuration/reconfiguration message.
  • the present invention is capable of deleting an RLC SDU received from a primary base station in a secondary base station, wherein any part of the RLC SDU has not been mapped to an RLC PDU and the corresponding PDCP SDU has been deleted due to expiration.
  • the present invention can reduce the storage of expired RLC SDUs in the secondary base station to save storage space, and can avoid transmitting expired RLC SDUs to save wireless transmission resources.
  • 1 is a schematic diagram of a dual connectivity deployment option 3C given in 3GPP TR 36.842;
  • FIG. 2 is a flowchart of a method for deleting a RLC SDU by a secondary base station according to an embodiment of the present invention
  • FIG. 3 is a flowchart of a method for a primary base station to send a delete RLC SDU indication message to a secondary base station according to an embodiment of the present disclosure
  • FIG. 4 is a flowchart of another method for a primary base station to send a delete RLC SDU indication message to a secondary base station according to an embodiment of the present disclosure
  • FIG. 5 is a flowchart of a method for another primary base station to send a delete RLC SDU indication message to a secondary base station according to an embodiment of the present disclosure
  • FIG. 6 is a schematic diagram of a bitmap provided by an embodiment of the present invention.
  • FIG. 7 is a flowchart of a method for another primary base station to send a delete RLC SDU indication message to a secondary base station according to an embodiment of the present disclosure
  • FIG. 8 is a flowchart of another method for a primary base station to send a delete RLC SDU indication message to a secondary base station according to an embodiment of the present disclosure
  • FIG. 9 is a block diagram of a secondary base station according to an embodiment of the present invention.
  • FIG. 10 is a block diagram of a primary base station according to an embodiment of the present invention.
  • the embodiments of the present invention are specifically described below with the LTE Rel-12 mobile communication system and its subsequent evolved versions as example application environments.
  • the present invention is not limited to the following embodiments, but can be applied to more other wireless communication systems, such as future 5G cellular communication systems.
  • the implementation example of the technical solution of the present invention is described herein only for the case where the primary base station and one secondary base station cooperate to provide communication services for the user equipment, the technical solution of the present invention will be equally applicable to the primary base station and one.
  • the above secondary base station cooperates to provide a communication service for the user equipment.
  • FIG. 2 is a schematic flowchart of an embodiment of a method for deleting a expired RLC SDU by a secondary base station according to an embodiment of the present invention.
  • the method shown in Figure 2 includes the following steps:
  • Step 201 The secondary base station receives the RLC SDU of the incoming autonomous base station, and starts an RLC deletion timer associated with the RLC SDU. Specifically, the secondary base station receives the RLC SDU from the primary base station, and initiates an RLC deletion timer associated with the RLC SDU. The timing period of the RLC deletion timer is carried in a request message sent by the primary base station to the secondary base station to allocate additional resources to the user equipment, or via an inter-node RRC message via the Xn.
  • the interface is configured as a secondary base station RLC entity.
  • the RRC message includes the following RLC-config information element fragment:
  • the RLC-discardtimer field is used to indicate the deletion time of the RLC SDU, in milliseconds.
  • the value ms50 represents 50 milliseconds
  • the value ms100 represents 100 milliseconds
  • the value of the RLC-discardtimer is not limited to the value shown in the radio resource control-configuration information element fragment. In essence, the value of the RLC-discardtimer should ensure that the deletion moment of the RLC SDU is at the same time or after the corresponding PDCP SDU is deleted.
  • RLC-discardtimer value should be greater than or equal PDCP discardtimer minus T MeNB-SeNB, the T MeNB-SeNB transmitted from the primary base station to the secondary base station is time PDCP PDU.
  • PDCP discardtimer minus T MeNB-SeNB
  • T MeNB-SeNB transmitted from the primary base station to the secondary base station is time PDCP PDU.
  • Step 202 The secondary base station determines whether the RLC deletion timer associated with each RLC SDU received by the RLC entity expires. If the RLC deletion timer has not expired, step 203 is performed; otherwise, step 204 is performed;
  • Step 203 The secondary base station sequentially takes out the unexpired RLC SDUs from the RLC SDU buffer, maps them into RLC PDUs, and deletes the RLC deletion timer associated with the RLC SDUs.
  • the unexpired RLC SDUs are sequentially taken out, including but not limited to: the unexpired RLC SDUs are taken out in order of RLC SDU sequence numbers from small to large or according to the RLC SDU receiving chronological order.
  • the RLC SDU may be divided into multiple segments, and each segment is mapped to a different RLC PDU. When any segment of the RLC SDU is mapped to the RLC PDU, the timer is deleted, and the timer is not deleted until all segments of the RLC SDU are mapped to the RLC PDU.
  • Step 204 Delete the RLC SDU whose RLC timer has expired and has not been mapped to the RLC PDU.
  • FIG. 3 is a schematic flowchart diagram of another embodiment of a method for deleting a expired RLC SDU by a secondary base station according to an embodiment of the present invention.
  • the method shown in Figure 3 includes the following steps:
  • Step 301 The deletion timer associated with the PDCP SDU expires, and the primary base station deletes the PDCP SDU. Specifically, the primary base station monitors a deletion timer associated with each PDCP SDU in the PDCP SDU receiving buffer, and deletes the PDCP SDU expired by the associated deletion timer from the receiving buffer.
  • Step 302 The primary base station determines whether the PDCP SDU expired by the deletion timer has been mapped to the PDCP PDU. If it has been mapped to the PDCP PDU, step 303 is performed; otherwise, the received deletion timer of each PDCP SDU is continuously monitored.
  • Step 303 The primary base station determines whether the PDCP PDU to which the expired PDCP SDU is mapped is saved locally. If the local storage is saved, step 304 is performed; otherwise, step 305 is performed.
  • Step 304 The primary base station deletes the locally saved PDCP PDU.
  • Step 305 The primary base station determines whether the PDCP PDU to which the expired PDCP SDU is mapped has been sent to the RLC entity in the secondary base station. If yes, go to step 306. Otherwise, continue to monitor the received deletion timing of each PDCP SDU. Device.
  • Step 306 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message may include one or more RLC SDU sequence numbers, and may also include a bitmap.
  • FIG. 4 is a flowchart of an embodiment of determining, by a primary base station, whether to send a Delete RLC SDU indication message to a secondary base station by determining the number of expired PDCP SDUs.
  • the method shown in Figure 4 includes the following steps:
  • Step 4001 The primary base station sets the value of the first timer to a statistical period for the PDCP entity and starts the first timer.
  • the statistical period is that the primary base station sends the maximum time interval for deleting the RLC SDU indication message to the secondary base station, and the statistical period can be configured to the PDCP of the primary base station by using a radio resource control configuration or a reconfiguration (RRC (re-) configuration).
  • RRC reconfiguration
  • Step 4002 The deletion timer associated with the PDCP SDU expires, and the primary base station deletes the PDCP SDU. Specifically, the primary base station monitors a deletion timer associated with each PDCP SDU in the PDCP SDU receiving buffer, and deletes the PDCP SDU expired by the associated deletion timer from the receiving buffer.
  • Step 4003 The primary base station determines whether the PDCP SDU expired by the deletion timer has been mapped to the PDCP PDU. If it has been mapped to the PDCP PDU, step 4004 is performed; otherwise, step 4011 is performed.
  • Step 4004 The primary base station determines whether the PDCP PDU to which the expired PDCP SDU is mapped is stored locally. If the local storage is saved, step 4005 is performed. Otherwise, step 4006 is performed.
  • Step 4005 The primary base station deletes the locally saved PDCP PDU.
  • Step 4006 The primary base station determines whether the PDCP PDU to which the expired PDCP SDU is mapped has been sent to the RLC entity in the secondary base station; if it has been sent, step 4007 is performed; otherwise, step 4011 is performed.
  • Step 4007 The primary base station locally saves the expired PDCP SDU sequence number.
  • Step 4008 The primary base station determines whether the locally stored expired PDCP SDU sequence number has reached the set value, and the set value is locally saved when the primary base station sends the delete RLC SDU indication message to the secondary base station.
  • the number of expired PDCP SDU sequence numbers, the number of sequence numbers can be configured into the primary base station PDCP entity by radio resource control configuration (reconfiguration). If the set value has been reached, step 4009 is performed; otherwise, step 4011 is performed.
  • Step 4009 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message includes a locally saved list of expired PDCP SDU sequence numbers.
  • the indication message further includes a locally saved number of expired PDCP SDU sequence numbers.
  • Step 4010 The primary base station determines whether the PDCP SDU has been sent. If the transmission has been completed, the method ends; otherwise, step 4001 is performed.
  • Step 4011 The primary base station determines whether the first timer expires, and the first timer is used to determine a maximum time interval for the primary base station to send the RLC SDU indication message to the secondary base station, where the value of the first timer can pass the wireless resource.
  • the control configuration (reconfiguration) mode is configured in the primary base station PDCP entity. If the first timer expires, step 4009 is performed; otherwise, step 4012 is performed.
  • Step 4012 The primary base station determines whether the PDCP SDU has been sent. If it has been sent, then Go to step 4013; otherwise, go to step 4002.
  • Step 4013 The primary base station sends a delete RLC SDU indication message to the secondary base station.
  • FIG. 5 is a flowchart of an embodiment of a method for determining, by a primary base station, whether to send a delete RLC SDU indication message to a secondary base station by determining whether a second timer expires.
  • the method shown in Figure 5 includes the following steps:
  • Step 5001 The primary base station sets the value of the second timer to a statistical period for the PDCP entity and starts a second timer.
  • the statistic period is that the primary base station sends the time interval for deleting the RLC SDU indication message to the secondary base station, and the statistic period can be configured in the RRC (re-configuration) mode to the PDCP entity of the primary base station.
  • Step 5002 The deletion timer associated with the PDCP SDU expires, and the primary base station deletes the PDCP SDU. Specifically, the primary base station monitors a deletion timer associated with each PDCP SDU in the PDCP SDU receiving buffer, and deletes the PDCP SDU expired by the associated deletion timer from the receiving buffer.
  • Step 5003 The primary base station determines whether the PDCP SDU expired by the deletion timer has been mapped to the PDCP PDU. If it has been mapped to a PDCP PDU, step 5004 is performed; otherwise, step 5008 is performed.
  • Step 5004 The primary base station determines whether the PDCP PDU to which the expired PDCP SDU is mapped is stored locally. If there is a local save, step 5005 is performed; otherwise, step 5006 is performed.
  • Step 5005 The primary base station deletes the locally saved PDCP PDU.
  • Step 5006 The primary base station determines whether the PDCP PDU to which the expired PDCP SDU is mapped has been sent to the RLC entity in the secondary base station. If it has been sent, step 5007 is performed; otherwise, step 5008 is performed.
  • Step 5007 The primary base station locally saves the expired PDCP SDU sequence number.
  • Step 5008 The primary base station determines whether the second timer expires. If the second timer has expired, step 5009 is performed; otherwise, step 5011 is performed.
  • Step 5009 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message includes a locally saved list of expired PDCP SDU sequence numbers.
  • the indication message further includes a locally saved number of expired PDCP SDU sequence numbers.
  • Step 5010 The primary base station determines whether the PDCP SDU has been sent. If the transmission has been completed, the method ends; otherwise, step 5001 is performed.
  • Step 5011 The primary base station determines whether the PDCP SDU has been sent. If it has been sent, step 5012 is performed; otherwise, step 5002 is performed.
  • Step 5012 The primary base station sends a delete RLC SDU indication message to the secondary base station.
  • Fig. 6 shows a schematic diagram of a bitmap structure.
  • the length of the bitmap shown in Figure 6 can be fixed or variable.
  • the bitmap indication bit value of 1 indicates that the corresponding PDCP SDU has expired, and a value of 0 indicates that the corresponding PDCP SDU has not expired. All PDCP SDUs sent by the primary base station are expired, and the corresponding bitmap indication bit value Both are 0.
  • there are 10 PDCP SDUs to be sent in the primary base station where the PDCP SDUs with sequence numbers 1, 2, 5, 7, and 9 are transmitted through the RLC entity located at the primary base station, and the sequence numbers are 0, 3, 4, and 6.
  • the PDCP SDU of 8 is transmitted by the RLC entity located at the secondary base station.
  • the sequence numbers of the expired PDCP SDUs corresponding to the bitmap shown in FIG. 6 are 4 and 6, respectively, because the PDCP SDU with the sequence number 5 passes the primary base station.
  • the RLC entity in the middle sends, so the PDCP SDU with the sequence number of 5 has a value of 0 in the bitmap regardless of whether it expires or not.
  • the PDCP SDU sequence number with sequence number 3 is listed in the Minimum Sequence Number field of the expired PDCP SDU in the message header indicating the message, and thus need not be indicated in the bitmap.
  • FIG. 7 is a flow chart of an embodiment of a variable length bitmap provided by the present invention. The method shown in Figure 7 includes the following steps:
  • Step 7001 The primary base station sets the value of the third timer to a statistical period for the PDCP entity and starts a third timer.
  • the statistic period is that the primary base station sends the time interval for deleting the RLC SDU indication message to the secondary base station, and the statistic period can be configured in the RRC (re-configuration) mode to the PDCP entity of the primary base station.
  • Step 7002 The PDCP entity in the primary base station monitors a deletion timer associated with each PDCP SDU received from the upper layer. If the delete timer expires, the PDCP SDU associated with the expired delete timer is deleted.
  • Step 7003 The primary base station determines whether the deleted PDCP SDU has been mapped to a PDCP PDU. If it has been mapped to the PDCP PDU, step 7004 is performed; otherwise, step 7008 is performed.
  • Step 7004 The primary base station determines whether the PDCP PDU to which the deleted PDCP SDU is mapped is saved locally. If the PDCP PDU is saved locally, step 7005 is performed; otherwise, step 7006 is performed.
  • Step 7005 The primary base station deletes the PDCP PDU to which the deleted PDCP SDU is mapped.
  • Step 7006 The primary base station determines whether the PDCP PDU to which the deleted PDCP SDU is mapped has been sent to the RLC entity of the secondary base station. If the RLC entity has been sent to the secondary base station, step 7007 is performed; otherwise, step 7008 is performed.
  • Step 7007 The primary base station locally saves the PDCP SDU sequence number.
  • Step 7008 The primary base station determines whether the third timer expires. If it has expired, step 7009 is performed; otherwise, step 7011 is performed.
  • Step 7009 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message may include a minimum expired PDCP SDU sequence number locally saved by the primary base station and a bitmap generated by the primary base station according to the locally saved expired PDCP SDU sequence number.
  • the indication message further includes a bitmap length.
  • Step 7010 The primary base station determines whether the PDCP SDU has been sent. If the transmission has been completed, the method ends; otherwise, step 7001 is performed.
  • Step 7011 The primary base station determines whether the PDCP SDU has been sent. If it has been sent, step 7012 is performed; otherwise, step 7002 is performed.
  • Step 7012 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message may include a minimum expired PDCP SDU sequence number locally saved by the primary base station and a bitmap generated by the primary base station according to the locally saved expired PDCP SDU sequence number.
  • the indication message further includes a bitmap length.
  • Figure 8 shows a flow diagram of an example embodiment employing a fixed length bitmap. The method shown in Figure 8 includes the following steps:
  • Step 8001 The primary base station sets the value of the fourth timer to the statistical period for the PDCP entity and starts the fourth timer.
  • the statistical period is a time interval for the primary base station to send the RLC SDU indication message to the secondary base station, and the statistics period may be configured or reconfigured by the RRC (RRC)
  • RRC RRC
  • the (re-)configuration mode is configured in the PDCP entity of the primary base station.
  • the maximum expired PDCP SDU sequence number and the minimum expired PDCP SDU sequence number are set to initial values, which are different values from the PDCP SDU sequence number to be transmitted, for example, may be -1, infinity, infinity.
  • Step 8002 The PDCP entity in the primary base station monitors a deletion timer associated with each PDCP SDU received from the upper layer. If the delete timer expires, the PDCP SDU associated with the expired delete timer is deleted.
  • Step 8003 The primary base station determines whether the deleted PDCP SDU has been mapped to a PDCP PDU. If it has been mapped to the PDCP PDU, step 8004 is performed; otherwise, step 8008 is performed.
  • Step 8004 The primary base station determines whether the PDCP PDU to which the deleted PDCP SDU is mapped is stored locally. If the PDCP PDU is saved locally, step 8005 is performed; otherwise, step 8006 is performed.
  • Step 8005 The primary base station deletes the PDCP PDU to which the deleted PDCP SDU is mapped.
  • Step 8006 The primary base station determines whether the PDCP PDU to which the deleted PDCP SDU is mapped has been sent to the RLC entity of the secondary base station. If it has been sent to the RLC entity of the secondary base station, step 8007 is performed; otherwise, step 8008 is performed.
  • Step 8007 The primary base station locally saves the PDCP SDU sequence number that has expired and has been sent to the secondary base station RLC entity. If the minimum expired PDCP SDU sequence number is an initial value or greater than the locally saved expired PDCP SDU sequence number, the minimum expired PDCP SDU sequence number is set to the locally saved expired PDCP SDU sequence number.
  • Step 8008 If the maximum expired PDCP SDU sequence number is an initial value or the maximum expired PDCP SDU sequence number is smaller than the deleted expired PDCP SDU sequence number, updating the maximum expired PDCP SDU sequence number to the deleted The PDCP SDU serial number has expired.
  • Step 8009 The primary base station determines whether the difference between the maximum expired PDCP SDU sequence number and the minimum expired PDCP SDU sequence number is equal to the bitmap length. If it is equal to the bitmap length, step 8010 is performed; otherwise, step 8012 is performed.
  • the bitmap length can be configured in the PDCP entity of the primary base station by means of radio resource control configuration or reconfiguration (RRC (re-) configuration).
  • Step 8010 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message may include a minimum expired locally saved by the primary base station.
  • Step 8011 The primary base station determines whether the PDCP SDU has been sent. If the transmission has been completed, the method ends; otherwise, step 8001 is performed.
  • Step 8012 The primary base station determines whether the difference between the maximum expired PDCP SDU sequence number and the minimum expired PDCP SDU sequence number is greater than the bitmap length. If it is greater than the bitmap length, step 8016 is performed; otherwise, step 8013 is performed.
  • Step 8013 The primary base station determines whether the fourth timer expires. If it has expired, step 8010 is performed; otherwise, step 8014 is performed.
  • Step 8014 The primary base station determines whether the PDCP SDU has been sent. If it has been sent, step 8015 is performed; otherwise, step 8002 is performed.
  • Step 8015 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message may include a minimum expired PDCP SDU sequence number locally saved by the primary base station and a bitmap generated by the primary base station according to the locally saved expired PDCP SDU sequence number.
  • Step 8016 The primary base station sends a delete RLC SDU indication message to the secondary base station, so that the secondary base station deletes the corresponding RLC SDU according to the indication message, where the RLC SDU is not yet mapped to the RLC PDU.
  • the indication message may include a minimum expired PDCP SDU sequence number locally saved by the primary base station and a bitmap generated by the primary base station according to the locally saved expired PDCP SDU sequence number.
  • the primary base station restarts the fourth timer, and if the PDCP SDU to which the recently expired PDCP SDU is mapped is sent by the RLC SDU of the secondary base station, the minimum sequence number of the expired PDCP SDU is set to the most recently expired PDCP SDU sequence. No. Otherwise, set the minimum sequence number of the expired PDCP SDU to the initial value.
  • Step 8017 The primary base station determines whether the PDCP SDU has been sent. If it has been sent, step 8015 is performed; otherwise, step 8002 is performed.
  • FIG. 9 is a block diagram of a secondary base station according to an embodiment of the present invention.
  • the secondary base station 90 in this embodiment includes a timer starting unit 910, a first deleting unit 920, and a second deleting unit 920.
  • the timer initiation unit 910 is configured to initiate activation of an RLC SDU received from the primary base station The associated RLC delete timer.
  • the first deletion unit 920 is configured to delete the RLC deletion timer if the RLC deletion timer has not expired and the RLC SDU is mapped to an RLC PDU.
  • the second deletion unit 930 is configured to delete the RLC SDU if the RLC deletion timer expires.
  • the RLC deletion timer is set by a request message sent by the primary base station for adding additional resources to the user equipment or by an inter-node radio resource control message. More preferably, the RLC deletion timer satisfies the condition that the deletion time of the associated RLC SDU is at the same time or after the expiration time of the PDCP SDU corresponding to the primary base station.
  • FIG. 10 is a block diagram of a primary base station according to an embodiment of the present invention.
  • the primary base station 100 in this embodiment includes a first deleting unit 1010 and a transmitting unit 1030.
  • the first deletion unit 1010 is configured to delete the PDCP SDU if the deletion timer associated with the PDCP SDU expires.
  • the primary base station 100 includes a second deletion unit 1020, and the second deletion unit 1020 is configured to delete the PDCP PDU if the PDCP PDU mapped by the deleted PDCP SDU is locally saved.
  • the sending unit 1030 is configured to: if the deleted PDCP PDU has been sent to the secondary base station, send an indication message for deleting the RLC SDU corresponding to the deleted PDCP PDU to the secondary base station, where the corresponding RLC SDU has not yet been Is mapped to an RLC PDU.
  • the primary base station may further include a storage unit (not shown) configured to hold the sequence number of the expired PDCP SDU.
  • the sending unit 1030 is further configured to: if the number of saved sequence numbers of the expired PDCP SDUs reaches a preset number, send the indication message to the secondary base station; or if the first timing When the device expires, the indication message is sent to the secondary base station, where the first timer is used to determine a maximum time interval for the primary base station to send the indication message to the secondary base station.
  • the primary base station may further include a storage unit (not shown) configured to hold the sequence number of the expired PDCP SDU.
  • the sending unit 1030 is further configured to: if the second timer expires, send the indication message to the secondary base station, where the second timer is configured to determine that the primary base station sends the indication to the secondary base station The time interval of the message.
  • the primary base station may further include a storage unit (not shown) configured to hold the sequence number of the expired PDCP SDU.
  • the sending unit 1030 is further configured to: if the third timer expires, send the indication message to the secondary base station, where the third timer is used to determine that the primary base station sends the indication message to the secondary base station. a time interval; the indication message includes a minimum sequence number, a bitmap length, and a bitmap of the expired PDCP SDU, and the minimum sequence number of the expired PDCP SDU is within the timing period of the third timer The minimum sequence number of the expired PDCP SDU sent by the base station.
  • the primary base station may further include a storage unit (not shown) configured to hold the sequence number of the expired PDCP SDU.
  • the sending unit 1030 is further configured to: if the difference between the maximum sequence number of the expired PDCP SDU and the minimum sequence number of the expired PDCP SDU is greater than or equal to the bitmap length, send the station to the secondary base station Or the indication message; or, if the fourth timer expires, sending the indication message to the secondary base station, where the fourth timer is used to determine a maximum time interval for the primary base station to send the indication message to the secondary base station.
  • the indication message includes a minimum sequence number and a bitmap of the expired PDCP SDU, and the maximum sequence number of the expired PDCP SDU is the PDCP that has expired in the primary base station in the timing period of the fourth timer.
  • the maximum sequence number of the SDU, and the minimum sequence number of the expired PDCP SDU is the minimum sequence number of the expired PDCP SDU sent by the secondary base station in the timing period of the fourth timer.
  • the first timer, the second timer, the third timer or the fourth timer in the above example may be configured by a radio resource control configuration/reconfiguration message.
  • the bitmap length may be sent in a request message sent by the primary base station to the secondary base station to allocate additional resources to the user equipment, or may be a secondary base station RLC entity via the Xn interface through the radio resource control message between the base stations. To configure.
  • the present invention it is possible to delete an RLC SDU received from a primary base station in a secondary base station, wherein any part of the RLC SDU has not been mapped to an RLC PDU and the corresponding PDCP SDU has been deleted due to expiration, thereby reducing the expired RLC SDU Storage in the secondary base station to save storage space and to avoid transmission of expired RLC SDUs to save wireless transmission resources.
  • the above-described embodiments of the present invention can be implemented by software, hardware, or a combination of both software and hardware.
  • the base station and various internal components in the above embodiments may be implemented by various devices including, but not limited to, analog circuit devices, digital circuit devices.
  • DSP digital signal processing
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • CPLD programmable logic devices
  • base station refers to a mobile communication data and control switching center having a large transmission power and a relatively large coverage area, including resource allocation scheduling, data reception and transmission, and the like.
  • User equipment refers to a user mobile terminal, for example, a terminal device including a mobile phone, a notebook, etc., which can perform wireless communication with a base station or a micro base station.
  • embodiments of the invention disclosed herein may be implemented on a computer program product.
  • the computer program product is a product having a computer readable medium encoded with computer program logic that, when executed on a computing device, provides related operations to implement The above technical solution of the present invention.
  • the computer program logic When executed on at least one processor of a computing system, the computer program logic causes the processor to perform the operations (methods) described in the embodiments of the present invention.
  • Such an arrangement of the present invention is typically provided as software, code and/or other data structures, or such as one or more, that are arranged or encoded on a computer readable medium such as an optical medium (e.g., CD-ROM), floppy disk, or hard disk.
  • Software or firmware or such a configuration may be installed on the computing device such that one or more processors in the computing device perform the technical solutions described in the embodiments of the present invention.

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Abstract

本发明提供了一种在辅基站中执行的方法，用于删除从主基站接收的无线链路控制"RLC"服务数据单元"SDU"，所述方法包括以下步骤：启动与从主基站接收的RLC SDU相关联的RLC删除计时器；如果所述RLC删除计时器未到期并且所述RLC SDU任一部分被映射为无线链路控制"RLC"协议数据单元"PDU"，则删除所述RLC删除计时器；以及如果所述RLC删除计时器到期，则删除所述RLC SDU。本发明还提供了相应的主基站和辅基站。本发明可减少已过期的RLC SDU在辅基站中的存储以节省存储空间，并可避免传输已过期的RLC SDU以节省无线传输资源。

Description

用于删除无线链路控制服务数据单元的方法和基站 技术领域
本发明涉及移动通信，具体地，涉及删除无线链路控制服务数据单元的方法和相应的基站。
背景技术
第三代伙伴计划(3GPP)长期演进(LTE)系统的层2用户平面协议栈由3个子层组成，从高到低依次为：分组数据汇聚协议(Packet Data Convergence Protocol，PDCP)层、无线链路控制(Radio Link Control，RLC)层和媒体接入控制(Media Access Control)层。在发送端，从高层接收服务数据单元(Service Data Unit，SDU)，为该层提供业务，并向低层输出协议数据单元(Protocol Data Unit，PDU)。例如：RLC层接收来自PDCP的分组。这些分组对PDCP层来说是PDCP PDU，但对RLC层来说是RLC SDU。在接收端，该过程是相反的，每层向上层发送SDU，上层作为PDU接收。PDCP SDU经IP报头压缩、加密并附加PDCP报头后映射成为PDCP PDU。RLC SDU按照MAC层指定的大小进行分块/串联并增加RLC报头后映射为RLC PDU。PDCP SDU由PDCP序列号标识，PDCP SDU与对应的PDCP PDU和RLC SDU具有相同的序列号，RLC PDU由RLC序列号标识。
在3GPP LTE版本11中，每一无线承载(bearer)有一个PDCP实体和一个RLC实体。每个基站(也称为NodeB或演进NodeB(eNB))和每个用户设备(UE)均有一个MAC实体。基站和用户设备中PDCP SDU的存储时间(又称丢弃时间)通过删除计时器(discardtimer)控制。当PDCP层接收到来自上层的PDCP SDU时，启动相关联的删除计时器，当所述删除计时器到期时，删除与所述删除计时器关联的PDCP SDU，同时向位于同一基站或用户设备中的RLC层发送指示。所述RLC层接收到所述指示后，如果对应的RLC SDU还没有被映射到RLC PDU，则删除所述RLC SDU。这里，用户设备可以是用户终端，用户节点，移动终端或平板电脑。
在正在制定的3GPP LTE版本12标准中，包含关于具有双连接(dual connectivity)能力的用户设备、主基站(Master eNB，MeNB)、辅基站(Secondary eNB，SeNB)的标准制定工作。主基站负责维护用户设备的无线资源管理测量配置并且基于接收到的测量报告或流量状况或承载类型向辅基站请求为用户设备提供额外的资源(也称服务小区)。辅基站接收到主基站的请求后为用户设备配置服务小区或因没有足够的资源而拒绝所述请求。
基于承载分离的不同方式和用户平面协议栈，在3GPP TSG-RAN2第83bis次会议上，确定1A和3C两种用户平面架构作为双连接部署方式的标准化选项。图1示出的选项3C具有如下特征：(1)主基站通过S1-U接口与业务网关通信；(2)承载在主基站中分离；(3)对于分离的承载，在主基站和辅基站中都有对应RLC实体。在选项3C中，位于辅基站的RLC实体与上层(即位于主基站的PDCP实体)通过Xn接口进行交互，所述Xn接口包括X2接口。
在非双连接部署方案中，由于PDCP实体和RLC实体处于同一个基站，RLC SDU的时延控制可通过PDCP SDU的时延控制实现，即当PDCP SDU因删除计时器到期而被删除时，如果对应的RLC SDU还没有被映射到RLCPDU，则删除所述RLC SDU。上述非双连接部署方案中删除RLC SDU的流程为基站内部实现，故无需标准化。
但在双连接部署方案选项3C中，分离承载对应的PDCP实体和其中一个RLC实体位于主基站中，而另一个RLC实体位于辅基站中。现有非双连接部署方案无法解决双连接部署方案中辅基站中的RLC SDU时延控制问题，从而使得已经过期的RLC SDU在辅基站中长时间存储或传输，这将导致辅基站存储空间的浪费和无线传输资源的浪费。
因此，在双连接部署方案中，需要一种机制来删除辅基站中从主基站接收到的RLC SDU，其中该RLC SDU任一部分还未映射到RLC PDU并且对应的PDCP SDU因到期已被删除。
发明内容
为了解决上述技术问题，本发明提供了删除无线链路控制服务数据单元的方法和相应的基站。
具体地，根据本发明的第一方面，提供了一种在辅基站中执行的方法，用于删除从主基站接收的无线链路控制“RLC”服务数据单元“SDU”，所述方法包括以下步骤：启动与从主基站接收的RLC SDU相关联的RLC删除计时器；如果所述RLC删除计时器未到期并且所述RLC SDU任一部分被映射为无线链路控制“RLC”协议数据单元“PDU”，则删除所述RLC删除计时器；以及如果所述RLC删除计时器到期，则删除所述RLC SDU。
在一个实施例中，所述RLC删除计时器是通过主基站发送的用于为用户设备增加额外资源的请求消息或通过节点间无线资源控制消息而设置的；以及所述RLC删除计时器满足以下条件：相关联的RLC SDU的删除时间在主基站中所对应的分组数据汇聚协议“PDCP”服务数据单元“SDU”的到期时间的同时或之后。
根据本发明的第二方面，提供了一种在主基站中执行的方法，用于删除辅基站中接收的来自主基站的无线链路控制“RLC”服务数据单元“SDU”，所述方法包括以下步骤：如果与分组数据汇聚协议“PDCP”服务数据单元“SDU”相关联的删除计时器到期，则删除所述PDCP SDU；以及如果删除的PDCP SDU所对应的PDCP PDU已经被发送给辅基站，则向辅基站发送用于删除与所述PDCP PDU相对应的RLC SDU的指示消息，所述相对应的RLC SDU任一部分还未被映射为无线链路控制“RLC”协议数据单元“PDU”。
在一个实施例中，所述方法还包括：如果本地保存有删除的PDCP SDU所映射的分组数据汇聚协议“PDCP”协议数据单元“PDU”，则删除所述PDCP PDU。
在一个实施例中，所述方法还包括：保存已到期的PDCP SDU的序列号；如果保存的已到期的PDCP SDU的序列号的个数达到预设个数，则向辅基站发送所述指示消息；或者，如果第一计时器到期，则向辅基站发送所述指示消息，所述第一计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔。
在一个实施例中，所述方法还包括：保存已到期的PDCP SDU的序列号；以及如果第二计时器到期，则向辅基站发送所述指示消息，其中，所述第二计时器用于确定主基站向辅基站发送所述指示消息的时间间隔。
在一个实施例中，所述方法还包括：保存已到期的PDCP SDU的序列号；如果第三计时器到期，则向辅基站发送所述指示消息，所述第三计时器用于确定主基站向辅基站发送所述指示消息的时间间隔；其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最小序列号是第三计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
在一个实施例中，所述方法还包括：保存已到期的PDCP SDU的序列号；如果已到期的PDCP SDU的最大和最小序列号之差大于或等于位图长度，则向辅基站发送所述指示消息；或者，如果第四计时器到期，则向辅基站发送所述指示消息，所述第四计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔；其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最大序列号是第四计时器的计时周期内主基站中已到期的PDCP SDU的最大序列号，所述已到期的PDCP SDU的最小序列号是第四计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
在一个实施例中，通过无线资源控制配置/重配置消息来配置第一计时器、第二计时器、第三计时器或第四计时器。
根据本发明的第三方面，提供了一种辅基站，能够删除从主基站接收的无线链路控制“RLC”服务数据单元“SDU”，所述辅基站包括：计时器启动单元，被配置为：启动与从主基站接收的RLC SDU相关联的RLC删除计时器；第一删除单元，被配置为：如果所述RLC删除计时器未到期并且所述RLC SDU任一部分被映射为无线链路控制“RLC”协议数据单元“PDU”，则删除所述RLC删除计时器；以及第二删除单元，被配置为：如果所述RLC删除计时器到期，则删除所述RLC SDU。
在一个实施例中，所述RLC删除计时器是通过主基站发送的用于为用户设备增加额外资源的请求消息或通过节点间无线资源控制消息而设置 的；以及所述RLC删除计时器满足以下条件：相关联的RLC SDU的删除时间在主基站中所对应的分组数据汇聚协议“PDCP”服务数据单元“SDU”的到期时间的同时或之后。
根据本发明的第四方面，提供了一种主基站，能够删除辅基站中接收的来自主基站的无线链路控制“RLC”服务数据单元“SDU”，所述主基站包括：第一删除单元，被配置为：如果与分组数据汇聚协议“PDCP”服务数据单元“SDU”相关联的删除计时器到期，则删除所述PDCP SDU；以及发送单元，被配置为：如果删除的PDCP SDU所对应的PDCP PDU已经被发送给辅基站，则向辅基站发送用于删除与所述PDCP PDU相对应的RLC SDU的指示消息，所述相对应的RLC SDU任一部分还未被映射为无线链路控制“RLC”协议数据单元“PDU”。
在一个实施例中，所述主基站还包括：第二删除单元，被配置为：如果本地保存有删除的PDCP SDU所映射的分组数据汇聚协议“PDCP”协议数据单元“PDU”，则删除所述PDCP PDU。
在一个实施例中，所述主基站还包括：存储单元，被配置为保存已到期的PDCP SDU的序列号；其中，所述发送单元还被配置为：如果保存的已到期的PDCP SDU的序列号的个数达到预设个数，则向辅基站发送所述指示消息；或者，如果第一计时器到期，则向辅基站发送所述指示消息，所述第一计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔。
在一个实施例中，所述主基站还包括：存储单元，被配置为保存已到期的PDCP SDU的序列号；其中，所述发送单元还被配置为：如果第二计时器到期，则向辅基站发送所述指示消息，其中，所述第二计时器用于确定主基站向辅基站发送所述指示消息的时间间隔。
在一个实施例中，所述主基站还包括：存储单元，被配置为保存已到期的PDCP SDU的序列号；其中，所述发送单元还被配置为：如果第三计时器到期，则向辅基站发送所述指示消息，所述第三计时器用于确定主基站向辅基站发送所述指示消息的时间间隔；所述指示消息包含已到期的PDCP SDU的最小序列号、位图长度、和位图，所述已到期的PDCP SDU 的最小序列号是第三计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
在一个实施例中，所述主基站还包括：存储单元，被配置为保存已到期的PDCP SDU的序列号；其中，所述发送单元还被配置为：如果已到期的PDCP SDU的最大和最小序列号之差大于或等于位图长度，则向辅基站发送所述指示消息；或者，如果第四计时器到期，则向辅基站发送所述指示消息，所述第四计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔；其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最大序列号是第四计时器的计时周期内主基站中已到期的PDCP SDU的最大序列号，所述已到期的PDCP SDU的最小序列号是第四计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
在一个实施例中，通过无线资源控制配置/重配置消息来配置第一计时器、第二计时器、第三计时器或第四计时器。
本发明能够删除辅基站中从主基站接收到的RLC SDU，其中该RLC SDU任一部分还未映射到RLC PDU并且对应的PDCP SDU因到期已被删除。从而，本发明可减少已过期的RLC SDU在辅基站中的存储以节省存储空间，并可避免传输已过期的RLC SDU以节省无线传输资源。
附图说明
通过下文结合附图的详细描述，本发明的上述和其它特征将会变得更加明显，其中：
图1为3GPP TR36.842中给出的双连接部署选项3C的示意图；
图2为本发明实施例提供的辅基站删除RLC SDU的方法的流程图；
图3为本发明实施例提供的主基站向辅基站发送删除RLC SDU指示消息方法的流程图；
图4为本发明实施例提供的另一主基站向辅基站发送删除RLC SDU指示消息方法的流程图；
图5为本发明实施例提供的另一主基站向辅基站发送删除RLC SDU指示消息方法的流程图；
图6为本发明实施例提供的位图的示意图；
图7为本发明实施例提供的另一主基站向辅基站发送删除RLC SDU指示消息方法的流程图；
图8为本发明实施例提供的另一主基站向辅基站发送删除RLC SDU指示消息方法的流程图；
图9为本发明实施例提供的辅基站的框图；以及
图10为本发明实施例提供的主基站的框图。
具体实施方式
下面，通过结合附图对本发明的具体实施例的描述，本发明的原理和实现将会变得明显。应当注意的是，本发明不应局限于下文所述的具体实施例。另外，为了简便起见，省略了对于本发明没有直接关联的公知技术的详细描述，以防止对本发明的理解造成混淆。
下文以LTE Rel-12移动通信系统及其后续的演进版本作为示例应用环境，具体描述了根据本发明的多个实施例。然而，需要指出的是，本发明不限于以下实施例，而是可适用于更多其它的无线通信系统，例如今后的5G蜂窝通信系统。另外，虽然此处仅针对主基站和一个辅基站协同为用户设备提供通信服务的情形描述了本发明技术方案的实现示例，本领域技术将意识到本发明的技术方案同样适用于主基站和一个以上的辅基站协同为用户设备提供通信服务的情形。
图2为本发明实施例辅基站删除到期RLC SDU方法的一个实施例的流程示意图。图2所示的方法包含如下步骤：
步骤201：辅基站接收到来自主基站的RLC SDU，启动与所述RLC SDU关联的RLC删除计时器。具体地，辅基站接收来自主基站的RLC SDU，启动与所述RLC SDU关联的RLC删除计时器。所述RLC删除计时器的计时周期携带在主基站向辅基站发送的为用户设备分配额外资源的请求消息中、或通过基站间的无线资源控制消息(inter-node RRC message)经由Xn 接口为辅基站RLC实体来配置。所述无线资源控制消息包含以下无线资源控制-配置信息元素(RLC-config information element)片段：
Figure PCTCN2015072213-appb-000001
Figure PCTCN2015072213-appb-000002
在上述无线资源控制-配置信息元素片段中，RLC-discardtimer域用于指示RLC SDU的删除时间，单位为毫秒。例如，值ms50表示50毫秒，值ms100表示100毫秒，等等。RLC-discardtimer的取值不限于所述无线资源控制-配置信息元素片段中示出的值。实质上，RLC-discardtimer的取值应确保RLC SDU的删除时刻在对应的PDCP SDU被删除的同时或之后。RLC-discardtimer的值应大于等于PDCP discardtimer值减去TMeNB-SeNB，所述TMeNB-SeNB为PDCP PDU从主基站发送到辅基站的时间。其他域的描述与3GPP TS 36.331版本11相同，在此不再赘述。
步骤202：辅基站判断RLC实体所接收的各RLC SDU所关联的RLC删除计时器是否到期。如果RLC删除计时器未到期，则执行步骤203；否则，执行步骤204；
步骤203：辅基站从RLC SDU缓冲区中按序取出未到期的RLC SDU，将其映射为RLC PDU，并删除所述RLC SDU关联的RLC删除计时器。按序取出未到期的RLC SDU包括但不限于：按照RLC SDU序列号从小到大的顺序或按照RLC SDU接收时间先后顺序来取出未到期的RLC SDU。实际情况中，RLC SDU可能分成多段，各段映射到不同的RLC PDU。当RLC SDU的任何一段映射到RLC PDU时就删除计时器，而不需要等到RLC SDU的各段全部映射为RLC PDU才删除计时器。
步骤204：删除RLC计时器已到期并且还未映射为RLC PDU的RLC SDU。
图3为本发明实施例提供的辅基站删除到期RLC SDU方法的另一个实施例的流程示意图。图3所示的方法包括如下步骤：
步骤301：PDCP SDU所关联的删除计时器到期，主基站删除所述PDCP SDU。具体地，主基站监测PDCP SDU接收缓冲区中各PDCP SDU所关联的删除计时器，将所关联的删除计时器到期的PDCP SDU从接收缓冲区中删除。
步骤302：主基站判断删除计时器到期的PDCP SDU是否已映射到PDCP PDU，如果已经映射为PDCP PDU，则执行步骤303；否则，继续监测接收到的各PDCP SDU的删除计时器。
步骤303：主基站判断本地是否保存有所述已到期的PDCP SDU映射到的PDCP PDU；如果本地有保存，则执行步骤304，否则执行步骤305。
步骤304：主基站删除本地保存的所述PDCP PDU。
步骤305：主基站判断已到期的PDCP SDU映射到的PDCP PDU是否已经发送给辅基站中的RLC实体；如果已经发送，则执行步骤306，否则，继续监测接收到的各PDCP SDU的删除计时器。
步骤306：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。
在本发明的实施例中，所述指示消息中可以包含一个或多个RLC SDU序列号，也可以包含位图。
以下结合附图，描述上述指示消息包含多个RLC SDU序列号的若干实例。
图4为本发明提供的主基站通过判断已到期的PDCP SDU的个数确定是否向辅基站发送删除RLC SDU指示消息实施例流程图。图4所示的方法包括以下步骤：
步骤4001：主基站为PDCP实体将第一计时器的值设置为统计周期并启动第一计时器。其中，该统计周期为主基站向辅基站发送删除RLC SDU指示消息的最大时间间隔，而且该统计周期可以通过无线资源控制配置或重配置(RRC(re-)configuration)方式配置到主基站的PDCP实体中。
步骤4002：PDCP SDU所关联的删除计时器到期，主基站删除所述PDCP SDU。具体地，主基站监测PDCP SDU接收缓冲区中各PDCP SDU所关联的删除计时器，将所关联的删除计时器到期的PDCP SDU从接收缓冲区中删除。
步骤4003：主基站判断删除计时器到期的PDCP SDU是否已映射到PDCP PDU。如果已经映射为PDCP PDU，则执行步骤4004；否则，执行步骤4011。
步骤4004：主基站判断本地是否保存有所述已到期的PDCP SDU映射到的PDCP PDU；如果本地有保存，则执行步骤4005，否则执行步骤4006。
步骤4005：主基站删除本地保存的PDCP PDU。
步骤4006：主基站判断已到期的PDCP SDU映射到的PDCP PDU是否已经发送给辅基站中的RLC实体；如果已经发送，则执行步骤4007，否则，执行步骤4011。
步骤4007：主基站本地保存已到期的PDCP SDU序列号。
步骤4008：主基站判断本地保存的已到期的PDCP SDU序列号是否已达到设定的值，所述设定的值为主基站在向辅基站发送删除RLC SDU指示消息时本地应保存的已到期的PDCP SDU序列号的个数，序列号个数可以通过无线资源控制配置(重配置)方式配置到主基站PDCP实体中。如果已达到设定的值，则执行步骤4009；否则，执行步骤4011。
步骤4009：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中包含本地保存的已到期的PDCP SDU序列号列表。可选的，所述指示消息中还包含本地保存的已到期的PDCP SDU序列号个数。
步骤4010：主基站判断PDCP SDU是否已发送完。如果已发送完，则方法结束；否则，执行步骤4001。
步骤4011：主基站判断第一计时器是否到期，所述第一计时器用于确定主基站向辅基站发送删除RLC SDU指示消息的最大时间间隔，所述第一计时器的值可以通过无线资源控制配置(重配置)方式配置到主基站PDCP实体中。如果第一计时器到期，则执行步骤4009；否则，执行步骤4012。
步骤4012：主基站判断PDCP SDU是否已发送完。如果已发送完，则 执行步骤4013；否则，执行步骤4002。
步骤4013：主基站向辅基站发送删除RLC SDU指示消息。
图5为本发明提供的主基站通过判断第二计时器是否到期确定是否向辅基站发送删除RLC SDU指示消息实施例流程图。图5所示的方法包括以下步骤：
步骤5001：主基站为PDCP实体将第二计时器的值设置为统计周期并启动第二计时器。该统计周期为主基站向辅基站发送删除RLC SDU指示消息的时间间隔，并且该统计周期可以通过无线资源控制配置或重配置(RRC(re-)configuration)方式配置到主基站的PDCP实体中。
步骤5002：PDCP SDU所关联的删除计时器到期，主基站删除所述PDCP SDU。具体地，主基站监测PDCP SDU接收缓冲区中各PDCP SDU所关联的删除计时器，将所关联的删除计时器到期的PDCP SDU从接收缓冲区中删除。
步骤5003：主基站判断删除计时器到期的PDCP SDU是否已映射到PDCP PDU。如果已经映射为PDCP PDU，则执行步骤5004；否则，执行步骤5008。
步骤5004：主基站判断本地是否保存有所述已到期的PDCP SDU映射到的PDCP PDU。如果本地有保存，则执行步骤5005；否则，执行步骤5006。
步骤5005：主基站删除本地保存的PDCP PDU。
步骤5006：主基站判断已到期的PDCP SDU映射到的PDCP PDU是否已经发送给辅基站中的RLC实体。如果已经发送，则执行步骤5007；否则，执行步骤5008。
步骤5007：主基站本地保存已到期的PDCP SDU序列号。
步骤5008：主基站判断第二计时器是否到期。如果第二计时器已到期，则执行步骤5009；否则，执行步骤5011。
步骤5009：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中包含本地保存的已到期的PDCP SDU序列号列表。可选的，所述指示消息中还包含本地保存的已到期的PDCP SDU序列号个数。
步骤5010：主基站判断PDCP SDU是否已发送完。如果已发送完，则方法结束；否则，执行步骤5001。
步骤5011：主基站判断PDCP SDU是否已发送完。如果已发送完，则执行步骤5012；否则，执行步骤5002。
步骤5012：主基站向辅基站发送删除RLC SDU指示消息。
以下，结合附图，描述指示消息包含位图的若干实例。
图6示出了位图结构示意图。图6所示位图的长度可以是固定或可变的。位图指示位值为1表示对应的PDCP SDU已经到期，值为0表示对应的PDCP SDU还未到期，所有通过主基站发送的PDCP SDU无论是否到期，对应的位图指示位取值均为0。例如：在主基站中有10个PDCP SDU需要发送，其中序列号为1、2、5、7、9的PDCP SDU通过位于主基站的RLC实体的发送，序列号为0、3、4、6、8的PDCP SDU通过位于辅基站的RLC实体发送。假设已到期的PDCP SDU的序列号最小为3，则图6示出的位图对应的已到期的PDCP SDU的序列号分别为4、6，因序列号为5的PDCP SDU通过主基站中的RLC实体发送，故所述序列号为5的PDCP SDU无论是否到期在位图中指示位的值均为0。所述序列号为3的PDCP SDU序列号在指示消息的消息头中的已到期的PDCP SDU的最小序列号字段中列出，故不需要在位图中指示。
图7为本发明提供的采用可变长度位图的实施例的流程图。图7所示的方法包括以下步骤：
步骤7001：主基站为PDCP实体将第三计时器的值设置为统计周期并启动第三计时器。该统计周期为主基站向辅基站发送删除RLC SDU指示消息的时间间隔，并且该统计周期可以通过无线资源控制配置或重配置(RRC(re-)configuration)方式配置到主基站的PDCP实体中。
步骤7002：主基站中的PDCP实体监测从上层接收的各PDCP SDU关联的删除计时器。如果所述删除计时器到期，则删除所述到期删除计时器关联的PDCP SDU。
步骤7003：主基站判断所述被删除的PDCP SDU是否已经映射到PDCP PDU。如果已经映射到PDCP PDU，则执行步骤7004；否则，执行步骤7008。
步骤7004：主基站判断本地是否保存有所删除的PDCP SDU映射到的PDCP PDU。如果本地保存有所述PDCP PDU，则执行步骤7005；否则，执行步骤7006。
步骤7005：主基站删除所述被删除的PDCP SDU所映射到的PDCP PDU。
步骤7006：主基站判断所删除的PDCP SDU映射到的PDCP PDU是否已发送给辅基站的RLC实体。如果已经发送给辅基站的RLC实体，则执行步骤7007；否则，执行步骤7008。
步骤7007：主基站本地保存PDCP SDU序列号。
步骤7008：主基站判断第三计时器是否到期。如果已到期，则执行步骤7009；否则，执行步骤7011。
步骤7009：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中可以包含主基站本地保存的最小已到期的PDCP SDU序列号及主基站根据本地保存的已到期的PDCP SDU序列号产生的位图。可选的，所述指示消息中还包含位图长度。
步骤7010：主基站判断PDCP SDU是否已发送完。如果已发送完，则方法结束；否则，执行步骤7001。
步骤7011：主基站判断PDCP SDU是否已发送完。如果已发送完，则执行步骤7012；否则，执行步骤7002。
步骤7012：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中可以包含主基站本地保存的最小已到期的PDCP SDU序列号及主基站根据本地保存的已到期的PDCP SDU序列号产生的位图。可选的，所述指示消息中还包含位图长度。
图8示出了采用固定长度位图的示例实施例的流程图。图8所示的方法包括以下步骤：
步骤8001：主基站为PDCP实体将第四计时器的值设置为统计周期并启动第四计时器。该统计周期为主基站向辅基站发送删除RLC SDU指示消息的时间间隔，并且该统计周期可以通过无线资源控制配置或重配置(RRC (re-)configuration)方式配置到主基站的PDCP实体中。同时，将最大已过期PDCP SDU序列号和最小已过期PDCP SDU序列号设置为初始值，所述初始值是不同于待发送PDCP SDU序列号的特殊值，例如可以是-1、无穷大、无穷小。
步骤8002：主基站中的PDCP实体监测从上层接收的各PDCP SDU关联的删除计时器。如果所述删除计时器到期，则删除所述到期删除计时器关联的PDCP SDU。
步骤8003：主基站判断所述被删除的PDCP SDU是否已经映射到PDCP PDU。如果已经映射到PDCP PDU，则执行步骤8004；否则，执行步骤8008。
步骤8004：主基站判断本地是否保存有所述被删除的PDCP SDU所映射到的PDCP PDU。如果本地保存有所述PDCP PDU，则执行步骤8005；否则，执行步骤8006。
步骤8005：主基站删除所述被删除的PDCP SDU所映射到的PDCP PDU。
步骤8006：主基站判断所述被删除的PDCP SDU映射到的PDCP PDU是否已发送给辅基站的RLC实体。如果已经发送给辅基站的RLC实体，则执行步骤8007；否则，执行步骤8008。
步骤8007：主基站本地保存已到期且已经发送给辅基站RLC实体的PDCP SDU序列号。如果最小已过期PDCP SDU序列号为初始值或大于所述本地保存的已过期PDCP SDU序列号，则将最小已过期PDCP SDU序列号设置为所述本地保存的已过期PDCP SDU序列号。
步骤8008：如果最大已过期PDCP SDU序列号为初始值或最大已过期PDCP SDU序列号小于所述被删除的已过期PDCP SDU序列号，则更新最大已过期PDCP SDU序列号为所述被删除的已过期PDCP SDU序列号。
步骤8009：主基站判断最大已到期的PDCP SDU序列号与最小已到期的PDCP SDU序列号之差是否等于位图长度。如果等于位图长度，则执行步骤8010；否则，执行步骤8012。该位图长度可以通过无线资源控制配置或重配置(RRC(re-)configuration)方式配置到主基站的PDCP实体中。
步骤8010：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中可以包含主基站本地保存的最小已到期 的PDCP SDU序列号及主基站根据本地保存的已到期的PDCP SDU序列号产生的位图。
步骤8011：主基站判断PDCP SDU是否已发送完。如果已发送完，则方法结束；否则，执行步骤8001。
步骤8012：主基站判断最大已到期的PDCP SDU序列号与最小已到期的PDCP SDU序列号之差是否大于位图长度。如果大于位图长度，则执行步骤8016；否则，执行步骤8013。
步骤8013：主基站判断第四计时器是否到期。如果已到期，则执行步骤8010；否则，执行步骤8014。
步骤8014：主基站判断PDCP SDU是否已发送完。如果已发送完，则执行步骤8015；否则，执行步骤8002。
步骤8015：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中可以包含主基站本地保存的最小已到期的PDCP SDU序列号及主基站根据本地保存的已到期的PDCP SDU序列号产生的位图。
步骤8016：主基站向辅基站发送删除RLC SDU指示消息，以便辅基站根据所述指示消息删除对应的RLC SDU，其中所述RLC SDU还没有被映射为RLC PDU。所述指示消息中可以包含主基站本地保存的最小已到期的PDCP SDU序列号及主基站根据本地保存的已到期的PDCP SDU序列号产生的位图。主基站重启第四计时器，如果最近到期的PDCP SDU所映射到的PDCP SDU通过辅基站的RLC SDU发送，则将已到期的PDCP SDU的最小序列号设置为最近到期的PDCP SDU序列号，否则，将已到期的PDCP SDU的最小序列号设置为初始值。
步骤8017：主基站判断PDCP SDU是否已发送完。如果已发送完，则执行步骤8015；否则，执行步骤8002。
图9为本发明实施例提供的辅基站的框图。如图9所示，本实施例中的辅基站90包括计时器启动单元910、第一删除单元920和第二删除单元920。
计时器启动单元910被配置为：启动与从主基站接收的RLC SDU相关 联的RLC删除计时器。
第一删除单元920被配置为：如果RLC删除计时器未到期并且RLC SDU被映射为RLC PDU，则删除所述RLC删除计时器。
第二删除单元930被配置为：如果所述RLC删除计时器到期，则删除所述RLC SDU。
优选地，所述RLC删除计时器是通过主基站发送的用于为用户设备增加额外资源的请求消息或通过节点间无线资源控制消息而设置的。更优选地，所述RLC删除计时器满足以下条件：相关联的RLC SDU的删除时间在主基站中所对应的PDCP SDU的到期时间的同时或之后。
图10为本发明实施例提供的主基站的框图。如图10所示，本实施例中的主基站100包括第一删除单元1010和发送单元1030。
第一删除单元1010被配置为：如果与PDCP SDU相关联的删除计时器到期，则删除所述PDCP SDU。
可选地，主基站100包括还可以第二删除单元1020，该第二删除单元1020被配置为：如果本地保存有删除的PDCP SDU所映射的PDCP PDU，则删除所述PDCP PDU。
发送单元1030被配置为：如果删除的PDCP PDU已经被发送给辅基站，则向辅基站发送用于删除与删除的PDCP PDU相对应的RLC SDU的指示消息，所述相对应的RLC SDU还未被映射为RLC PDU。
在一个优选示例中，主基站还可以包括存储单元(图中未示出)，该存储单元被配置为保存已到期的PDCP SDU的序列号。在此情况下，发送单元1030还被配置为：如果保存的已到期的PDCP SDU的序列号的个数达到预设个数，则向辅基站发送所述指示消息；或者，如果第一计时器到期，则向辅基站发送所述指示消息，所述第一计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔。
在一个优选示例中，主基站还可以包括存储单元(图中未示出)，该存储单元被配置为保存已到期的PDCP SDU的序列号。在此情况下，发送单元1030还被配置为：如果第二计时器到期，则向辅基站发送所述指示消息，其中，所述第二计时器用于确定主基站向辅基站发送所述指示消息的时间间隔。
在一个优选示例中，主基站还可以包括存储单元(图中未示出)，该存储单元被配置为保存已到期的PDCP SDU的序列号。在此情况下，发送单元1030还被配置为：如果第三计时器到期，则向辅基站发送所述指示消息，所述第三计时器用于确定主基站向辅基站发送所述指示消息的时间间隔；所述指示消息包含已到期的PDCP SDU的最小序列号、位图长度、和位图，所述已到期的PDCP SDU的最小序列号是第三计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
在一个优选示例中，主基站还可以包括存储单元(图中未示出)，该存储单元被配置为保存已到期的PDCP SDU的序列号。在此情况下，发送单元1030还被配置为：如果已到期的PDCP SDU的最大序列号和已到期的PDCP SDU的最小序列号之差大于或等于位图长度，则向辅基站发送所述指示消息；或者，如果第四计时器到期，则向辅基站发送所述指示消息，所述第四计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔。其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最大序列号是第四计时器的计时周期内主基站中已到期的PDCP SDU的最大序列号，所述已到期的PDCP SDU的最小序列号是第四计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
优选地，可以通过无线资源控制配置/重配置消息来配置上述示例中的第一计时器、第二计时器、第三计时器或第四计时器。
在本发明实施例中，所述位图长度可以在主基站向辅基站发送的为用户设备分配额外资源的请求消息中发送、或通过基站间的无线资源控制消息经由Xn接口为辅基站RLC实体来配置。
根据本发明，能够删除辅基站中从主基站接收到的RLC SDU，其中该RLC SDU任一部分还未映射到RLC PDU并且对应的PDCP SDU因到期已被删除，从而可减少已过期的RLC SDU在辅基站中的存储以节省存储空间，并可避免传输已过期的RLC SDU以节省无线传输资源。
应该理解，本发明的上述实施例可以通过软件、硬件或者软件和硬件两者的结合来实现。例如，上述实施例中的基站和内部的各种组件可以通过多种器件来实现，这些器件包括但不限于：模拟电路器件、数字电路器 件、数字信号处理(DSP)电路、可编程处理器、专用集成电路(ASIC)、现场可编程门阵列(FPGA)、可编程逻辑器件(CPLD)，等等。
在本申请中，“基站”是指具有较大发射功率和较广覆盖面积的移动通信数据和控制交换中心，包括资源分配调度、数据接收发送等功能。“用户设备”是指用户移动终端，例如包括移动电话、笔记本等可以与基站或者微基站进行无线通信的终端设备。
此外，这里所公开的本发明的实施例可以在计算机程序产品上实现。更具体地，该计算机程序产品是如下的一种产品：具有计算机可读介质，计算机可读介质上编码有计算机程序逻辑，当在计算设备上执行时，该计算机程序逻辑提供相关的操作以实现本发明的上述技术方案。当在计算系统的至少一个处理器上执行时，计算机程序逻辑使得处理器执行本发明实施例所述的操作(方法)。本发明的这种设置典型地提供为设置或编码在例如光介质(例如CD-ROM)、软盘或硬盘等的计算机可读介质上的软件、代码和/或其他数据结构、或者诸如一个或多个ROM或RAM或PROM芯片上的固件或微代码的其他介质、或一个或多个模块中的可下载的软件图像、共享数据库等。软件或固件或这种配置可安装在计算设备上，以使得计算设备中的一个或多个处理器执行本发明实施例所描述的技术方案。
尽管以上已经结合本发明的优选实施例示出了本发明，但是本领域的技术人员将会理解，在不脱离本发明的精神和范围的情况下，可以对本发明进行各种修改、替换和改变。因此，本发明不应由上述实施例来限定，而应由所附权利要求及其等价物来限定。

Claims (18)

  1. 一种在辅基站中执行的方法，用于删除从主基站接收的无线链路控制“RLC”服务数据单元“SDU”，所述方法包括以下步骤：
    启动与从主基站接收的RLC SDU相关联的RLC删除计时器；
    如果所述RLC删除计时器未到期并且所述RLC SDU任一部分被映射为无线链路控制“RLC”协议数据单元“PDU”，则删除所述RLC删除计时器；以及
    如果所述RLC删除计时器到期，则删除所述RLC SDU。
  2. 根据权利要求1所述的方法，其中，
    所述RLC删除计时器是通过主基站发送的用于为用户设备增加额外资源的请求消息或通过节点间无线资源控制消息而设置的；以及
    所述RLC删除计时器满足以下条件：相关联的RLC SDU的删除时间在主基站中所对应的分组数据汇聚协议“PDCP”服务数据单元“SDU”的到期时间的同时或之后。
  3. 一种在主基站中执行的方法，用于删除辅基站中接收的来自主基站的无线链路控制“RLC”服务数据单元“SDU”，所述方法包括以下步骤：
    如果与分组数据汇聚协议“PDCP”服务数据单元“SDU”相关联的删除计时器到期，则删除所述PDCP SDU；以及
    如果删除的PDCP SDU所对应的PDCP PDU已经被发送给辅基站，则向辅基站发送用于删除与所述PDCP PDU相对应的RLC SDU的指示消息。
  4. 根据权利要求3所述的方法，其中，如果本地保存有删除的PDCP SDU所映射的分组数据汇聚协议“PDCP”协议数据单元“PDU”，则删除所述PDCP PDU。
  5. 根据权利要求3所述的方法，其中，所述方法还包括：
    保存已到期的PDCP SDU的序列号；
    如果保存的已到期的PDCP SDU的序列号的个数达到预设个数，则向辅基站发送所述指示消息；或者，如果第一计时器到期，则向辅基站发送所述指示消息，所述第一计时器用于确定主基站向辅基站发送所述指示消 息的最大时间间隔。
  6. 根据权利要求3所述的方法，其中，所述方法还包括：
    保存已到期的PDCP SDU的序列号；以及
    如果第二计时器到期，则向辅基站发送所述指示消息，其中，所述第二计时器用于确定主基站向辅基站发送所述指示消息的时间间隔。
  7. 根据权利要求3所述的方法，其中，所述方法还包括：
    保存已到期的PDCP SDU的序列号；
    如果第三计时器到期，则向辅基站发送所述指示消息，所述第三计时器用于确定主基站向辅基站发送所述指示消息的时间间隔；
    其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最小序列号是第三计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
  8. 根据权利要求3所述的方法，其中，所述方法还包括：
    保存已到期的PDCP SDU的序列号；
    如果已到期的PDCP SDU的最大和最小序列号之差大于或等于位图长度，则向辅基站发送所述指示消息；或者，如果第四计时器到期，则向辅基站发送所述指示消息，所述第四计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔；
    其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最大序列号是第四计时器的计时周期内主基站中已到期的PDCP SDU的最大序列号，所述已到期的PDCP SDU的最小序列号是第四计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
  9. 根据权利要求5-8中任意一项所述的方法，其中，通过无线资源控制配置/重配置消息来配置第一计时器、第二计时器、第三计时器或第四计时器。
  10. 一种辅基站，能够删除从主基站接收的已到期的无线链路控制“RLC”服务数据单元“SDU”，所述辅基站包括：
    计时器启动单元，被配置为：启动与从主基站接收的RLC SDU相关联的RLC删除计时器；
    第一删除单元，被配置为：如果所述RLC删除计时器未到期并且所述RLC SDU任一部分被映射为无线链路控制“RLC”协议数据单元“PDU”，则删除所述RLC删除计时器；以及
    第二删除单元，被配置为：如果所述RLC删除计时器到期，则删除所述RLC SDU。
  11. 根据权利要求10所述的辅基站，其中，
    所述RLC删除计时器是通过主基站发送的用于为用户设备增加额外资源的请求消息或通过节点间无线资源控制消息而设置的；以及
    所述RLC删除计时器满足以下条件：相关联的RLC SDU的删除时间在主基站中所对应的分组数据汇聚协议“PDCP”服务数据单元“SDU”的到期时间的同时或之后。
  12. 一种主基站，能够删除辅基站中接收的来自主基站的无线链路控制“RLC”服务数据单元“SDU”，所述主基站包括：
    第一删除单元，被配置为：如果与分组数据汇聚协议“PDCP”服务数据单元“SDU”相关联的删除计时器到期，则删除所述PDCP SDU；以及
    发送单元，被配置为：如果删除的PDCP SDU所对应的PDCP PDU已经被发送给辅基站，则向辅基站发送用于删除与所述PDCP PDU相对应的RLC SDU的指示消息。
  13. 根据权利要求12所述的主基站，其中，所述主基站还包括：
    第二删除单元，被配置为：如果本地保存有删除的PDCP SDU所映射的分组数据汇聚协议“PDCP”协议数据单元“PDU”，则删除所述PDCP PDU。
  14. 根据权利要求12所述的主基站，其中，所述主基站还包括：
    存储单元，被配置为保存已到期的PDCP SDU的序列号；
    其中，所述发送单元还被配置为：如果保存的已到期的PDCP SDU的序列号的个数达到预设个数，则向辅基站发送所述指示消息；或者，如果第一计时器到期，则向辅基站发送所述指示消息，所述第一计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔。
  15. 根据权利要求12所述的主基站，其中，所述主基站还包括：
    存储单元，被配置为保存的已到期的PDCP SDU的序列号；
    其中，所述发送单元还被配置为：如果第二计时器到期，则向辅基站 发送所述指示消息，其中，所述第二计时器用于确定主基站向辅基站发送所述指示消息的时间间隔。
  16. 根据权利要求12所述的主基站，其中，所述主基站还包括：
    存储单元，被配置为保存的已到期的PDCP SDU的序列号；
    其中，所述发送单元还被配置为：如果第三计时器到期，则向辅基站发送所述指示消息，所述第三计时器用于确定主基站向辅基站发送所述指示消息的时间间隔；所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最小序列号是第三计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
  17. 根据权利要求12所述的主基站，其中，所述主基站还包括：
    存储单元，被配置为保存的已到期的PDCP SDU的序列号；
    其中，所述发送单元还被配置为：如果已到期的PDCP SDU的最大和最小序列号之差大于或等于位图长度，则向辅基站发送所述指示消息；或者，如果第四计时器到期，则向辅基站发送所述指示消息，所述第四计时器用于确定主基站向辅基站发送所述指示消息的最大时间间隔；
    其中，所述指示消息包含已到期的PDCP SDU的最小序列号和位图，所述已到期的PDCP SDU的最大序列号是第四计时器的计时周期内主基站中已到期的PDCP SDU的最大序列号，所述已到期的PDCP SDU的最小序列号是第四计时器的计时周期内通过辅基站发送的已到期的PDCP SDU的最小序列号。
  18. 根据权利要求14-17中任意一项所述的主基站，其中，通过无线资源控制配置/重配置消息来配置第一计时器、第二计时器、第三计时器或第四计时器。
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024017395A1 (zh) * 2022-07-22 2024-01-25 中国移动通信有限公司研究院 数据处理方法、装置及通信设备

Families Citing this family (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP6230859B2 (ja) * 2013-09-26 2017-11-15 株式会社Ｎｔｔドコモ 移動通信システム及び無線基地局
EP3179770B1 (en) * 2014-08-06 2020-01-01 Ntt Docomo, Inc. User equipment
EP3420695B1 (en) * 2016-02-23 2020-04-08 Telefonaktiebolaget LM Ericsson (PUBL) Methods used in user equipment and associated ues
CN107787009B (zh) * 2016-08-26 2022-09-27 中兴通讯股份有限公司 拥塞处理方法、装置及系统
US10999019B2 (en) * 2017-03-31 2021-05-04 Samsung Electronics Co., Ltd. Apparatus and buffer control method thereof in a wireless communication system
US11082889B2 (en) * 2017-04-25 2021-08-03 Lg Electronics Inc. Method and device for receiving data unit
EP3609229A4 (en) * 2017-04-25 2020-03-18 Guangdong Oppo Mobile Telecommunications Corp., Ltd. DATA TRANSFER METHOD AND COMMUNICATION DEVICE
CN108809540B (zh) * 2017-05-05 2021-09-17 华为技术有限公司 数据处理方法及设备
WO2018232559A1 (zh) * 2017-06-19 2018-12-27 北京小米移动软件有限公司 数据处理方法及装置、用户设备和计算机可读存储介质
EP4307588A3 (en) * 2017-06-20 2024-02-28 Apple Inc. Devices and methods for flow-control triggering and feedback
CN109565474B (zh) * 2017-07-25 2022-05-06 北京小米移动软件有限公司 数据传输方法及装置、电子设备和计算机可读存储介质
CN109756994B (zh) * 2017-08-25 2021-06-15 大唐移动通信设备有限公司 一种终端状态的恢复方法、装置、基站及终端
CN110167146B (zh) * 2018-02-12 2023-06-09 维沃移动通信有限公司 一种sdu的处理方法和通信设备
US11582160B2 (en) * 2018-09-27 2023-02-14 Lenovo (Beijing) Limited Discarding radio link control service data units
CN112838912A (zh) * 2019-11-22 2021-05-25 夏普株式会社 无线通信方法以及无线通信设备
CN111163081B (zh) * 2019-12-26 2022-04-22 展讯通信（上海）有限公司 数据传输方法、装置、设备及存储介质
CN112566256B (zh) * 2020-12-01 2023-04-07 重庆重邮汇测电子技术研究院有限公司 一种基于rlc um模式发送协议数据单元的方法
WO2023054954A1 (en) * 2021-09-28 2023-04-06 Lg Electronics Inc. Method and apparatus for performing pdcp sdu concatenation operation in wireless communication system

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101997660A (zh) * 2009-08-14 2011-03-30 中兴通讯股份有限公司 一种避免上行数据丢失的方法及装置

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6904016B2 (en) * 2001-11-16 2005-06-07 Asustek Computer Inc. Processing unexpected transmission interruptions in a wireless communications system
KR100802619B1 (ko) * 2002-11-07 2008-02-13 엘지전자 주식회사 무선 링크 제어 프로토콜에 따르는 수신기에서의 알엘씨데이터 수신 윈도우 처리 방법
WO2007130325A2 (en) * 2006-05-01 2007-11-15 Interdigital Technology Corporation Method and apparatus for facilitating lossless handover in 3gpp long term evolution systems
KR20070121602A (ko) * 2006-06-22 2007-12-27 이노베이티브 소닉 리미티드 무선 통신 시스템에서 패킷 폐기 방법 및 장치
AU2008308944B2 (en) * 2007-10-01 2012-07-26 Interdigital Patent Holdings, Inc. Method and apparatus for PCDP discard
US8208394B2 (en) * 2007-10-30 2012-06-26 Qualcomm Incorporated Service data unit discard timers
JP4952586B2 (ja) * 2008-01-07 2012-06-13 富士通株式会社 パケットデータの廃棄方法、無線通信装置、移動通信システム
CN101547141B (zh) * 2008-03-25 2012-06-27 华为技术有限公司 一种发送数据的方法、系统和设备
CN101729524B (zh) * 2008-11-03 2012-12-12 电信科学技术研究院 一种数据处理方法、装置、rlc实体及pdcp实体
CN102833802B (zh) * 2012-08-15 2015-09-23 电信科学技术研究院 一种数据转发方法及设备
KR102059042B1 (ko) * 2013-05-10 2020-02-11 주식회사 팬택 이중연결 시스템에서 멀티 플로우를 고려한 순차적 전달 방법 및 장치
KR102104493B1 (ko) * 2013-05-10 2020-05-04 주식회사 팬택 이중 연결성을 지원하는 무선 통신 시스템에서 데이터 전송 방법 및 장치
EP2830352A1 (en) * 2013-07-24 2015-01-28 Panasonic Intellectual Property Corporation of America Efficient discard mechanism in small cell deployment
US9648514B2 (en) * 2013-08-09 2017-05-09 Blackberry Limited Method and system for protocol layer enhancements in data offload over small cells
JP6230859B2 (ja) * 2013-09-26 2017-11-15 株式会社Ｎｔｔドコモ 移動通信システム及び無線基地局
US20150089382A1 (en) * 2013-09-26 2015-03-26 Wu-chi Feng Application context migration framework and protocol
JP6262991B2 (ja) * 2013-10-31 2018-01-17 株式会社Ｎｔｔドコモ ユーザ装置及び方法
CN104837127B (zh) * 2014-02-08 2019-12-31 夏普株式会社 由辅基站和主基站执行的通信方法以及相应的基站

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101997660A (zh) * 2009-08-14 2011-03-30 中兴通讯股份有限公司 一种避免上行数据丢失的方法及装置

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
ALCATEL -LUCENT ET AL.: "R2-133527, Discussion on Terminology of Dual Connectivity", 3GPP TSG RAN WG2 MEETING #83BIS, 7 October 2013 (2013-10-07), LJUBLJANA, SLOVENIA, XP000133527 *
NEC CORPORATION: "R3-140229, User Plane Protocol over X2 for Dual Connectivity", 3GPP TSG-RAN WG3#83, vol. 2, 10 February 2013 (2013-02-10), PRAGUE, CZECH, XP050738670 *
SHARP CORPORATION: "R2-142002, Discussion on Delay Control of RLC SDUs in SeNB for Split Bearer", 3GPP TSG RAN WG2 MEETING #86, vol. 2, 19 May 2014 (2014-05-19), SEOUL, KOREA, XP050789989 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024017395A1 (zh) * 2022-07-22 2024-01-25 中国移动通信有限公司研究院 数据处理方法、装置及通信设备

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