Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/0005—Control or signalling for completing the hand-off
  • H04W36/0055—Transmission or use of information for re-establishing the radio link
  • H04W36/0058—Transmission of hand-off measurement information, e.g. measurement reports
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/0005—Control or signalling for completing the hand-off
  • H04W36/0055—Transmission or use of information for re-establishing the radio link
  • H04W36/0069—Transmission or use of information for re-establishing the radio link in case of dual connectivity, e.g. decoupled uplink/downlink
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/0005—Control or signalling for completing the hand-off
  • H04W36/0083—Determination of parameters used for hand-off, e.g. generation or modification of neighbour cell lists
  • H04W36/0085—Hand-off measurements
  • H04W36/0094—Definition of hand-off measurement parameters
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/24—Reselection being triggered by specific parameters
  • H04W36/249—Reselection being triggered by specific parameters according to timing information
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04W—WIRELESS COMMUNICATION NETWORKS
  • H04W36/00—Hand-off or reselection arrangements
  • H04W36/24—Reselection being triggered by specific parameters
  • H04W36/32—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data
  • H04W36/324—Reselection being triggered by specific parameters by location or mobility data, e.g. speed data by mobility data, e.g. speed data

Definitions

• the present invention relates to communication systems, and more particularly to a method for determining mobility of a user equipment having dual connectivity in a communication system. Background technique
• Figure 1 shows a possible application scenario for a small cell. Many small cells are within the coverage of the macro cell. The user equipment can be served by both the macro cell and the small cell. The macro cell uses the existing frequency and has a larger coverage, while the small cell can use a higher frequency, such as 3.5 GHz, but its coverage is small. When the user equipment is jointly served by the macro cell and the small cell shown in Fig. 1, the user equipment needs to perform carrier aggregation between the stations.
• LTE-A has introduced, for example, carrier aggregation, but it can only be applied to the same site or different sites but has an ideal backhaul (ideal backhaul, unidirectional delay is almost 0, which can meet extremely high transmission) Application scenarios for capacity requirements).
• the current carrier aggregation can be reused (if the time synchronization is also in the macro cell and small The cells are satisfied).
• the user equipment has only one RRC connection.
• the small cell preferably has partial RRC functions, such as Radio Resource Management (RRM) in the frequency.
• RRM Radio Resource Management
• the small cell can directly send the resource configuration information of the current cell to the user equipment. Therefore, the user equipment has a dual connection.
• the user device Once the user device has a dual connection, the user device's movement will cause it to be different in small Move between cells.
• the existing mobility process cannot be applied to the case where the user equipment has dual connectivity. For example, when the backhaul between the macro cell and the small cell will result in a one-way 60 ms delay, if the macro cell performs the mobility decision for the frequency occupied by the small cell, the small cell will know the macro cell too late. The decision of mobility, which will result in wasted resources in the source small cell, because the source small cell may insist on allocating resources for the user equipment. Summary of the invention
• the present invention proposes a mobility procedure suitable for user equipment with dual connectivity.
• a method for determining mobility of a user equipment in a source small cell where the source small cell is located in a coverage area of a macro cell, and the user equipment is simultaneously configured by the macro cell and The source small cell service, where the method includes the following steps:
• step g further comprises:
• the step g further includes:
• step g further comprises:
• a method for assisting a source small cell to determine mobility of a user equipment in a user equipment where the source small cell is located in a coverage area of a macro cell, and the user equipment is simultaneously The macro cell and the source small cell service, where the method includes the following steps:
• said step ii comprises the steps of:
• said step ii further comprises the steps of:
• a method for assisting a source small cell to determine mobility of a user equipment in a macro cell is provided, where the source small cell is located in the coverage of the macro cell.
• the user equipment is served by the macro cell and the source small cell at the same time, where the method includes the following steps:
• the notification message is used to notify the macro cell which DRBs are established in the target small cell and/or which DRBs are not established in the target small cell, to And transmitting, by the macro cell, downlink data corresponding to the DRB established in the target small cell to the target small cell.
• the method further comprises the steps of:
• a method for determining a mobility of a user equipment by a source small cell in a macro cell where the source small cell is located in a coverage area of the macro cell, and the user equipment is simultaneously Serving by the macro cell and the source small cell, where the method includes the following steps:
• the notification message being used to notify the macro cell which DRBs are established in the target small cell and/or which DRBs are not established in the target small cell, for the The macro cell will correspond to the one established in the target small cell
• the downlink data of the DRB is sent to the target small cell.
• a method for determining a mobility of a user equipment by a source small cell in a target small cell where the source small cell is located in a coverage area of a macro cell, and the user equipment is simultaneously The macro cell and the source small cell service, where the method includes the following steps:
• step II interacting with the user equipment to enable the user equipment to access the target small cell.
• step II further comprises the following steps:
• the step II further comprises the following steps: - receiving, from the source small cell, the source small cell corresponding to the DRB established in the target small cell has not been transmitted to the User device data.
• FIG. 1 shows a network architecture diagram of a user equipment with dual connectivity according to an embodiment of the invention
• FIG. 2 is a flow chart showing a method for determining mobility of a user equipment by a source small cell in an embodiment of the invention
• FIG. 3 is a flow chart showing a method for determining a mobility of a source small cell for a user equipment according to another embodiment of the invention.
• FIG. 4 is a flow chart showing a method for determining mobility of a user equipment for a user equipment according to an implementation of the present invention
• Figure 5 shows a schematic diagram of the architecture of PDCP separation
• Figure 6 shows a schematic diagram of the architecture of RLC separation.
• Embodiment 1 Small cell is a mobility determination of a frequency occupied by a user equipment in a small cell. This embodiment will be described below with reference to FIG.
• step S21 first, the user equipment accesses only the macro cell. At this time, the user equipment has only one RRC connection with the macro cell.
• the macro cell configures a small cell for the user equipment based on channel conditions and throughput requirements of the user equipment.
• the macro cell and the source small cell coordinate resources allocated for the user equipment and acquire relevant configuration information of the source small cell from the source small cell. For example, if the user equipment needs to perform random access in the source small cell to obtain the timing advance, the macro cell coordinates the random access resource allocated to the user equipment with the source small cell; the source small cell allocates the source small cell to the user equipment.
• the Cell Radio Network Temporary Identifier (C-RNTI) the macro cell learns the C-RNTI allocated by the source small cell for the user equipment.
• C-RNTI Cell Radio Network Temporary Identifier
• step S23 the macro cell sends at least part of the downlink data to the source small cell, for transmitting the user equipment to the user equipment when the user equipment accesses the source cell; and the related information of the source small cell that the macro cell will acquire The configuration information is sent to the user device.
• the related configuration information of the source small cell includes:
• - common channel configuration such as random access channel configuration, PDSCH (Physical Downlink Shared Channel) configuration, etc.
• PDSCH Physical Downlink Shared Channel
• timing advance (TA) between the macro cell and the source small cell is different, the timing advance group (TAG) configuration of the source small cell;
• the DRB configuration (including its QoS (Quality of Service)) established in the source small cell;
• step S24 the user equipment receives relevant configuration information of the source small cell from the macro cell, and accesses the source small cell. At this point, the user device has a dual connection.
• the user equipment considers the source small cell as an inactive state, and after the user equipment receives an activation command to the source small cell from the macro cell by using MAC CE (Medium Access Control Control Element) signaling, the user equipment starts.
• the downlink control information (DCI, Downlink Control Information) is monitored in the source small cell.
• the user equipment receives the DCI from the source small cell to obtain the random access trigger.
• the user equipment performs random access in the source small cell and receives the source from the source.
• the user equipment considers the source small cell as an active state, and initiates random access in the source small cell according to the obtained configuration information of the source small cell.
• the random access procedure in the source small cell is successful, and the user equipment successfully accesses the source small cell.
• the user equipment has dual connectivity with the macro cell and the source small cell.
• the protocol architecture includes an enhanced user plane architecture and an enhanced control plane architecture.
• the architecture of the Packet Data Convergence Protocol split and the Radio Link Control split has a high probability of being adopted by 3GPP.
• PDCP separation refers to a certain data radio bearer DRB
• the downlink data of the (Data Radio Bearer) (obtained from the core network and transmitted by the core network to the macro base station through the S1 interface) is separated by the PDCP entity (Entity) located in the macro cell, and some or all of the user data is allocated to the located interface Xn.
• PDCP entity Entity located in the macro cell, and some or all of the user data is allocated to the located interface Xn.
• the DRB there is one PDCP entity in the macro cell base station, and two RLC entities in the macro cell base station and the small cell base station
• the part or all of the data is transmitted to the user equipment through the underlying MAC layer and the physical layer, PDCP.
• a schematic diagram of the split architecture is shown in Figure 5.
• the interface Xn shown in the figure represents an enhancement of the existing X2 interface.
• the RLC separation means that the downlink data of a certain DRB is separated by the RLC entity located in the macro cell, and some or all of the user data is allocated to the RLC sublayer entity located at the base station where the small cell is located (for the DRB, there is one in the macro cell base station)
• a PDCP entity and an RLC entity have an RLC sublayer entity at the small cell base station, the sublayer entity having segmentation and reassembly functions.
• Each of the macro cell base station and the small cell base station has a MAC entity), the part or all of the data Through the underlying MAC layer and physical layer Transfer to the user device.
• the macro cell base station may not include the RLC entity for reading the DRB, and the schematic diagram of the RLC separation architecture is shown in FIG. 6.
• the macro cell has a large coverage. Therefore, it is reasonable to place the main control functions such as NAS (Non Access Stratum) switching, paging and receiving system messages in the macro cell, thereby ensuring better performance and comparison to the core network. Less impact (less switching).
• small cell base stations may still need to have partial R M (Radio Resource Management) functionality due to local (or distributed) scheduling.
• the small cell base station can configure or reconfigure relevant parameters related to its local scheduling, such as radio bearer related parameters, for the user equipment through the RRC; the small cell base station can directly obtain the specified frequency from the user equipment (such as the frequency occupied by the small cell). The measurement report, so that small inter-cell interference coordination can be performed when performing local scheduling.
• the user equipment sends a measurement report to the source small cell.
• the measurement report can be a measurement report of the user equipment on the frequency occupied by the source small cell.
• the source small cell requires this type of measurement 1 for distributed scheduling, small inter-cell interference coordination, and mobility decisions on this frequency.
• the user equipment sends a measurement report on the other frequency to the macro cell for the macro cell to make a mobility decision.
• the user equipment can send the measurement good news on the read multiple frequencies to the source small cell, so that the source small cell can A mobility decision is made on the plurality of frequencies.
• the source small cell base station has a part of the R M function, for example, can receive the measurement report sent by the user equipment; can perform the mobility management at the small cell level; and can configure the parameters about the distributed scheduling in the source small cell.
• step S26 the source small cell determines the target small cell to serve the user equipment instead of the user based on the measurement report.
• the source small cell coordinates with the target small cell for the resource allocated by the user equipment, and acquires related configuration information of the target small cell from the target small cell. For example, if the user equipment needs to perform random access in the target small cell to obtain the timing advance, the source small cell coordinates the random access resource allocated to the user equipment with the target small cell through the X2 interface; the source small cell obtains through the X2 interface.
• the target small cell is the CR TI allocated to the user equipment. in case There is no X2 interface between the source small cell and the target small cell, then the source small cell can coordinate resource allocation by the macro cell and the target small cell.
• the target small cell may not accept all DRBs (data radio bearers) that the source small cell requests to establish. In some cases, only a portion of the DRB is allowed to establish in the target small cell.
• step S28 the source small cell sends the relevant configuration information of the target small cell to the user equipment, and releases the resource allocated for the user equipment.
• the configuration information of the target small cell includes: the frequency and bandwidth occupied by the target small cell, the antenna configuration of the target small cell, the physical cell identifier of the target small cell, the DRB configuration established in the target small cell, and the target small cell is the user equipment. Assigned CR TI, etc.
• the configuration information of the target small cell that the source small cell transmits to the user equipment includes only these partial DRBs.
• the source small cell may send data that is not yet transmitted to the user equipment corresponding to the local small cell of the DRB established in the target small cell to the target small cell.
• Method 1 The untransmitted RLC PDU of the source small cell needs to be forwarded to the target small cell. A channel needs to be established between the two small cells to transmit untransmitted RLC PDUs.
• Method 2 If the PDCP entity of the macro cell base station can record which PDCP PDUs are allocated to the source small cell or have the retransmission function, the macro cell can transmit the source small cell corresponding to the DB established in the target small cell. Sending data to the user equipment to the user equipment; or the macro cell can send data corresponding to the source small cell of the DRB established in the target small cell to the target small cell, and send the data to the user equipment by the target small cell. .
• the RLC entity of the macro cell base station can transmit the untransmitted LC PDU to the target small cell.
• the source small cell should correspond to the DRB not established in the target small cell.
• the transmission data is sent to the macro cell.
• step S28B the source small cell informs the macro cell which DRBs are built in the target small cell. And/or which DRBs are not established in the target small cell for the macro cell to transmit downlink data corresponding to the DB established in the target small cell to the target small cell.
• step S29 the user equipment receives relevant configuration information of the target small cell from the source small cell and accesses the target small cell.
• the user equipment considers the target small cell as inactive. After the user equipment receives the MAC CE command carrying the activation indication from the macro cell, the user equipment starts monitoring the DCI in the target small cell; or the user equipment directly Random access is initiated in the target small cell according to the relevant configuration information of the target small cell. The user equipment receives a random access response at the target small cell.
• the user equipment can know from the relevant configuration information of the target small cell whether a random access procedure in the target small cell is necessary. For example, if the small cell and the macro cell belong to different timing advance groups, the user equipment needs to perform random access in the target small cell to obtain timing advance.
• the user equipment may receive the DCI from the target small cell to obtain a random access trigger, and the DCI may include a dedicated random access preamble Preamble; or the user equipment directly initiates random access in the target small cell. If the random access procedure in the target small cell is successful, the user equipment successfully accesses the target small cell.
• the user equipment needs to reconstruct the RLC for the DRB established in the target small cell.
• the MAC is reset for the target small cell.
• the user equipment first accesses the target small cell (step S39), and then the target small cell informs the macro cell which DRBs are established in the target small cell and/or which DRBs.
• the downlink data of the DRB established in the target small cell is not transmitted to the target small cell (step S310).
• the step drives S31 to S38A in Fig. 3 are similar to steps S21 to S28A in Fig. 2, and the description will not be repeated for the sake of brevity.
• the user equipment Only in step S39, the user equipment directly initiates random access in the target small cell according to the relevant configuration information of the target small cell.
• the source small cell can be found by using the measurement report reported by the user equipment.
• the target small cell that continues to serve the user equipment. If there is no small cell that can serve the user equipment, the source small cell directly releases its connection with the user equipment, and the source small cell needs to forward the untransmitted RLC PDU of the source small cell to the macro cell (the architecture for PDCP separation). At this point, the user equipment only maintains a single RRC connection with the macro cell.
• Embodiment 2 The macro cell is determined by the frequency occupied by the small cell for mobility
• the macro cell receives the measurement from the user equipment at the frequency occupied by the source small cell, and therefore the macro cell determines the mobility of the frequency occupied by the source small cell. As shown in Figure 4.
• step S45 the user equipment transmits a measurement report on the frequency occupied by the source small cell to the macro cell, so that the frequency occupied by the macro cell for the source small cell is determined as a mobility. Therefore, in step S46, the macro cell determines the target small cell to serve the user equipment instead of the source small cell.
• the user equipment also sends a measurement report on the frequency occupied by the source small cell to the source small cell, so that the source small cell can perform distributed scheduling and possible small inter-cell interference coordination.
• step S48 the macro cell transmits the relevant configuration information of the target small cell to the user equipment.
• step S47A the macro cell informs the source small cell to release the resource allocated for the user equipment.
• the macro cell can notify the source small cell user equipment that the target small cell is to be connected, so that if the PDCP separation architecture is adopted, the source small cell can forward the untransmitted RLC PDU to the target small cell.
• step S410 does not exist.

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• Signal Processing (AREA)
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• 2013
  • 2013-05-13 JP JP2016513188A patent/JP2016521530A/ja active Pending
  • 2013-05-13 US US14/890,656 patent/US20160119831A1/en not_active Abandoned
  • 2013-05-13 EP EP13884938.5A patent/EP2999263A4/en not_active Withdrawn
  • 2013-05-13 WO PCT/CN2013/075544 patent/WO2014183252A1/zh not_active Ceased
  • 2013-05-13 CN CN201380075468.0A patent/CN105191401B/zh active Active

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