JP6683856B2 - Data transmission method, access network device, and communication system - Google Patents

Description

  Embodiments of the present invention relate to communication technology, and more particularly to a data transmission method, an access network device, and a communication system.

  LTE networks are widely applied because Long Term Evolution (LTE for short) networks support relatively high bandwidth and have relatively strong anti-interference ability. Referring to FIG. 1, FIG. 1 is a schematic diagram of a system architecture of an existing LTE network. As shown in FIG. 1, the LTE network mainly includes an evolved terrestrial radio access network (E-UTRAN) 110 and a core network (CN) 120. The E-UTRAN mainly includes an evolved base station, which is also referred to as an evolved Node B (abbreviated eNB) 111. The core network 120 mainly includes a Mobility Management Entity (MME for short) 121, a Serving Gateway (S-GW for short) 122, a Policy and Charging Rules Function (abbreviated for short). PCRF) entity 123, packet data network gateway (PDN Gateway, P-GW for short) 124, and the like. User equipment (User Equipment, UE for short) accesses a wireless network via the eNB 111 and establishes a connection to an external network, for example, the Internet via the core network.

  In the E-UTRAN protocol architecture, the control plane (also referred to as the signaling plane) and the user plane (also referred to as the data plane) are separated. That is, control plane data and user plane data between the eNB 111 and the core network are processed by using different network elements. User plane data is transmitted between the eNB 111 and the S-GW 122 in the core network 120, and an interface between the eNB 111 and the S-GW 122 is defined as an S1 user plane interface (S1-U interface for short). The control plane data is transmitted between the eNB 111 and the MME 121, and the interface between the eNB 111 and the MME 121 is defined as the S1 control plane interface (abbreviated as S1-MME interface). When the UE has service, the user plane bearer is established by using the control plane, and if the bearer is successful, the user plane data may be transmitted by using the bearer.

  Currently, when the control plane connection is interrupted, ie the connection between the eNB and the MME is interrupted, the eNB immediately releases the control plane resources and the user plane resources, resulting in a user service interruption, Affect the user experience.

  In this regard, embodiments of the present invention provide data transmission methods, access network devices, and communication systems to reduce the impact of control plane interruptions on the user experience.

  A first aspect of the present invention is a data transmission method, wherein the method is applied to a communication system, the communication system includes an access network device and a core network device, and the core network device is a first core. A control plane interface including a network element and a second core network element is provided between the access network device and the first core network element, and a user plane interface is included in the access network device and the second core network. An access network device, the method comprising: obtaining, by the access network device, information about a bearer that needs to be established from the first core network element through the control plane interface. The step of establishing the bearer according to the information about the bearer that needs to be established, and the access network device notifying the second core network element of the established bearer through the first core network element. And transmitting the data to be transmitted in the existing service of the user equipment (UE) by using the established bearer when the control network interface signal is interrupted by the access network device. And a method including steps.

  With reference to the first aspect, in a first possible implementation method of the first aspect, the method comprises a first timer, by the access network device, when the access network device receives data of the UE. A step of starting or resetting, wherein the first timer is configured to record a period of inactivity of the UE, and the access network device, when the first timer expires Releasing the Radio Resource Control (RRC) connection.

  With reference to the first aspect or the first possible implementation method of the first aspect, in the second possible implementation method of the first aspect, the method comprises the control network interface by the access network device. Detecting whether the signal returns to normal, and releasing the RRC connection of the UE when the signal of the control plane interface returns to normal by the access network device.

  With reference to the first aspect or the first and second possible implementation methods of the first aspect, in the third possible implementation method of the first aspect, the method comprises the signal of the control plane interface. Is interrupted, the access network device starts a second timer, and when the second timer expires, the access network device releases the RRC connection of the UE.

  With reference to any one of the first aspect or the first to third possible implementation methods of the first aspect, in the fourth possible implementation method of the first aspect, the control plane interface If the UE starts to establish a control plane connection for a new service before the signal returns to normal, the access network device releases the UE's RRC connection.

  With reference to any one of the first aspect or the first to fourth possible mounting methods of the first aspect, in a fifth possible mounting method of the first aspect, said method comprises: A step of setting, by the access network device, a state of a cell covered by the access network device to a reserved state when the signal of the control plane interface is interrupted, the reserved state being a UE in an idle state. Further comprising the steps used to prohibit access to the.

  A second aspect of the present invention is an access network device, wherein the access network device is applied to a communication system, the communication system includes the access network device and a core network device, and the core network device comprises: A control plane interface including a first core network element and a second core network element is provided between the access network device and the first core network element, and a user plane interface is provided between the access network device and the first core network element. A processing module provided between the two core network elements and configured to obtain information about a bearer that needs to be established from the first core network element through the control plane interface. The processing module and the second core through the first core network element, the processing module being further configured to establish the bearer according to the information about the bearer that needs to be established. A transmission module configured to notify a network element of the established bearer, wherein the transmission module uses the established bearer when the signal of the control plane interface is interrupted. And a transmission module, further configured to transmit data to be transmitted within an existing service of the (UE).

  With reference to the second aspect, in the first possible implementation method of the second aspect, the processing module starts or resets a first timer when the access network device receives the data of the UE. The first timer is configured to record an inactive period of the UE, and releasing the radio resource control (RRC) connection of the UE when the first timer expires.

  With reference to the second aspect or the first possible implementation method of the second aspect, in the second possible implementation method of the second aspect, the processing module causes the signal of the control plane interface to be normal. Is further configured to release the RRC connection of the UE when the control plane interface signal returns to normal.

  With reference to the second aspect or the first and second possible implementation methods of the second aspect, in the third possible implementation method of the second aspect, the processing module comprises: It is further configured to start a second timer when the signal is interrupted and release the RRC connection of the UE when the second timer expires.

  In the fourth possible mounting method of the second aspect, with reference to any one of the first to third possible mounting methods of the second aspect or the second aspect, the processing module Is further configured to release the RRC connection of the UE if the UE starts to establish a control plane connection for a new service before the signaling of the control plane interface returns to normal.

  In the fifth possible mounting method of the second aspect, with reference to any one of the first to fourth possible mounting methods of the second aspect or the second aspect, the processing module , When the signal of the control plane interface is interrupted, it sets the state of the cells covered by the access network device to the reserved state, the reserved state being used to prohibit access of idle UEs. It is further configured as follows.

  A third aspect of the present invention is an access network device, which includes a processor, a memory, an interface circuit, and a system bus, and the processor, the memory, and the interface circuit use the system bus. Connected to and in communication with each other by, the memory is configured to store computer-executed instructions, the interface circuit is configured to communicate with another device, and the processor is of the first aspect or the first aspect. An access network device is provided that is configured to execute the computer-executed instructions to perform the method according to any one of the first to fifth possible implementation methods.

  A fourth aspect of the present invention is a communication system including an access network device and a core network device, the core network device including a first core network element and a second core network element, and a control plane interface comprising: A user plane interface is provided between the access network device and the first core network element, a user plane interface is provided between the access network device and the second core network element, and the access network device has a second aspect or There is provided a communication system having the structure provided in any possible implementation method of the second aspect.

  Embodiments of the present invention provide a data transmission method, an access network device, and a communication system. The method applies to communication systems in which the control plane is separate from the user plane. The communication system includes an access network device and a CN device, the CN device includes a first CN element and a second CN element, a control plane interface is provided between the first CN element and the access network device, and a user A plane interface is provided between the second CN element and the access network device. The access network device obtains information about a bearer that needs to be established from the first CN element through the control plane interface, establishes a bearer according to the information about the bearer that needs to be established, and uses the bearer. The established bearer is notified to the second CN element through the first CN element. When the signal of the control plane interface is interrupted, the access network device uses the established bearer to transmit the data to be transmitted in the existing service of the UE. In the method, when the signaling of the control plane interface is interrupted, the access network device does not immediately release the bearer of the UE. In this way, the UE's user plane connection is not broken and the UE can continue to use the established bearer to send data, maximizing the guarantee that the user plane service will not be interrupted, and thus the user Improve your experience.

In order to more clearly describe the technical solutions of the embodiments of the present invention or the prior art, the accompanying drawings required for describing the embodiments or the prior art will be described below. Apparently, the accompanying drawings in the following description are some embodiments of the present invention, and other drawings can be obtained according to these drawings by a person skilled in the art without creative efforts.
1 is a schematic diagram of a system architecture of an existing LTE network. It is a signaling flowchart of existing data transmission. 6 is a flowchart of a data transmission method according to an exemplary embodiment of the present invention. 7 is a flowchart of a data transmission method according to another embodiment of the present invention. FIG. 3 is a schematic structural diagram of an access network device according to an embodiment of the present invention. FIG. 6 is a schematic structural diagram of another access network device according to an embodiment of the present invention. 1 is a schematic structural diagram of a communication system according to an embodiment of the present invention.

  In order to clarify the objects, technical solutions, and advantages of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings in the embodiments of the present invention. Enter. Apparently, the described embodiments are some but not all of the embodiments of the present invention. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

  In the prior art, when the control plane is interrupted, the eNB immediately releases Radio Resource Control (RRC for short) connections of all UEs on the S1 link. It can be seen that the interruption of the control plane connection causes an immediate interruption of user service, affecting the user experience. In the present application, the data transmission process is analyzed, and when the control plane is interrupted but the user plane is established, the conclusion that the UE with which the user bearer is established can continue to transmit data and uses this conclusion Ensures that user services are not affected.

  Specifically, referring to FIG. 2, FIG. 2 is a signaling flowchart of existing data transmission. As shown in FIG. 2, the UE data transmission process includes the following steps.

  S201. When the UE has a service, the UE sends a service request to the MME via the eNB.

  Subsequently, there are processes such as authentication for the UE, these processes being irrelevant to the essence of the invention and not described in detail here.

  S202. The MME sends an initial context setup request message to the eNB.

  The initial context setup request message may include a UE context and an E-UTRAN radio access bearer (E-RAB for short) context. The E-RAB context includes information such as the address of the S-GW and the Tunnel Endpoint Identifier (TEID for short) used for uplink transmission.

  S203. The eNB knows the radio bearer (bearer for short) that needs to be established according to the E-RAB context included in the initial context setup request, allocates radio resources to the bearer and configures the bearer for the UE, thereby Complete bearer establishment.

  S204. The eNB transmits the UE data to the S-GW by using the established bearer.

  The existence of this step depends on whether the UE has uplink data to be transmitted.

  S205. The eNB sends an initial context setup complete message to the MME after bearer establishment is complete.

  The initial context setup complete message may carry information such as the eNB's address, the TEID used for downlink transmissions, and established bearers (also referred to as accepted bearers).

  S206. The MME sends a modify bearer request message to the S-GW regarding the established bearer in order to send information such as the address of the eNB to the S-GW by using the modified bearer request message.

  S207. The S-GW returns a modified bearer response message to the MME, which carries the address of the S-GW and the TEID used for uplink transmission.

  In LTE networks, the control plane is separate from the user plane. Furthermore, it can be seen from the above procedure that the UE with which the bearer is established can still send data as usual by using the user plane after the control plane connection is interrupted. Based on this, in the data transmission method provided in the embodiment of the present invention, the RRC connection of the UE is not released immediately after the control plane connection of the UE is interrupted, and the service of the UE can be continued.

  A detailed description is provided below with reference to the accompanying drawings.

  FIG. 3 is a flowchart of a data transmission method according to an exemplary embodiment of the present invention. The method applies to communication systems such as LTE networks, where the control plane is separate from the user plane. The communication system includes an access network device and a CN device. The CN device includes a first CN element and a second CN element. The first CN element is configured to process control plane data, and the control plane interface is provided between the first CN element and the access network device. The second CN element is configured to process user plane data and the user plane interface is provided between the second CN element and the access network device. As shown in FIG. 3, the method provided in this embodiment may include the following steps.

  S301. The access network device obtains from the first CN element through the control plane interface information about the bearer that needs to be established.

  From the above description, the access network device can obtain the information about the bearer that needs to be established in the initial context setup request message, and the information about the bearer that needs to be established is the E-RAB context. I know it's good. The E-RAB context may include information such as the address of the S-GW and the TEID used for uplink transmission.

  S302. The access network device establishes a bearer according to the bearer information that needs to be established.

  S303. The access network device sends the UE data to the second CN element by using the established bearer.

  Note that after the bearer is established, step S303 is performed when the UE has data to be transmitted. After step S302, if the UE has no data to be transmitted, the access network device does not need to perform step S303.

  S304. The access network device notifies the established second bearer to the second CN element through the first CN element.

  From the above description, the access network device may send the established bearer to the first CN element by using the initial context setup complete message, and the first CN element may send the established bearer by using the modified bearer request message. It can be seen that it sends to the second CN element.

  It should be noted that step S303 may be absent, or may be performed before or after step S304, or may be performed concurrently with S304.

  S305. When the control plane interface signal is interrupted, the access network device uses the established bearer to send the data to be sent within the UE's existing service.

  In the above method, the access network device does not immediately release the bearer of the UE when the control plane interface signaling is interrupted. In this way, the UE's user plane connection is not broken and the UE can continue to use the established bearer to send data, maximizing the guarantee that the user plane service will not be interrupted and thereby the user Improve experience, especially reliability of Voice over internet protocol (VOIP for short) service. The method described above is particularly applicable to situations where the first CN element is out of service for a short period of time, for example situations where the first CN element performs a version replacement, a software update or an abnormal reset.

  It should be noted that an access network device in this application represents a device that allows a UE to access a wireless network, which may be, for example, an eNB in an LTE network, or the user plane is separated from the control plane. It may be a base station in another communication system. The first CN element is configured to process control plane data and may be, for example, an MME in an LTE network. The second CN element is configured to process user plane data and may be, for example, an S-GW in an LTE network.

  Further, the signal disruption of the control plane interface in step S305 may be detected by the access network device and may be detected by detecting the link between the access network device and the first CN element. For example, in the LTE system, the interruption of the signal of the control plane interface in step S305 is performed by detecting whether or not the stream control transmission protocol (Stream Control Transmission Protocol, SCTP) link between the eNB and the MME is faulty. , ENB detect. The SCTP link is the underlying link between the eNB and the MME, and the SCTP link may carry the control plane connection for multiple UEs. When the SCTP link is down, the control plane connections for all UEs and carried on the SCTP link are broken.

  The eNB may detect whether or not the SCTP link between the eNB and the MME has a failure by the following method. The eNB periodically detects heartbeat packets sent by the MME, and if the eNB does not receive the heartbeat packet sent by the MME within a specified time, the eNB determines that the SCTP link is down. Of course, the eNB may detect in another way whether the SCTP link between the eNB and the MME is down. For example, if the eNB sends a heartbeat packet to the MME and the MME's response is not received within the preset time, then the SCTP link is considered to be down. This is not limited in this embodiment as long as the method can be used to detect whether normal transmission can be performed on the link.

  In the LTE network, the control plane connection of the UE includes two parts: a radio interface connection between the UE and the eNB and an S1-MME connection between the eNB and the MME. The radio connection between the UE and the eNB is an RRC connection. After the SCTP link fails, only the S1-MME connection is broken, but the radio interface connection between the UE and the eNB is not broken. The user plane connection of the UE also includes two parts: a radio interface connection between the UE and the eNB, and a connection between the eNB and the S-GW.

  In this embodiment, if the eNB detects that the SCTP link is down, the eNB does not release the RRC connection that is that of the UE and is carried on the SCTP link. In this way, the UE's user plane connection is not broken, the UE can continue to use the user plane resources for transmitting data, and the user service is not interrupted. Here, the user plane resource represents a bearer established between the eNB and the S-GW.

  From the above embodiments, it is possible that when the control plane interface signaling is interrupted, the access network device does not actively release the UE and may maintain this state until the UE actively exits the network. I understand. However, the first timer may be set in consideration of the use of radio resources. The first timer may be represented as an inactive timer. The inactivity timer is configured to record the UE inactivity time. For example, the access network device may monitor whether the UE sends or receives data. If the UE does not send or receive data for the duration of the inactivity timer, the access network device may actively release the UE. The inactivity timer is started when the UE has data to be transmitted or received. For example, upon receiving the uplink or downlink data of the UE, the access network device may start this timer. Moreover, the duration of the inactivity timer may be preset according to requirements. The following factors may be considered during setup.

  If the period is set shorter, the UE is released sooner when there is no service, which may cause the UE to frequently make RRC connection requests. Moreover, increasing the amount of normal release results in better network performance indicators, such as call drop rates obtained through statistics. If the period is set longer, the UE will be released later when there is no service and the UE will stay online and occupy radio resources for a longer time. Furthermore, the reduction in the amount of normal release results in worse network performance indicators, such as call drop rates obtained through statistics.

  The above two points may be taken into account and balanced during the setting of the duration of the inactivity timer. Furthermore, timers of different durations may be set for data and voice services to meet the different requirements of the two services.

  Furthermore, in order to keep the state of all UEs on the first CN element consistent, the access network device shall release all UEs on the S1 link when the signaling of the control plane interface returns to normal, ie The RRC connection may be released. For example, if the eNB detects that the state of the S-MME underlying SCTP link returns to normal, then all UEs on the S1 link are released in order to be consistent with the initial state of the UE on the MME.

  One or both of the two release conditions described above may be used: expiration of the inactivity timer and the control plane interface returning to normal. When both two release conditions are used, the UE's RRC connection may be released when any one of the conditions is met. For example, if the control plane interface signal returns to normal before the inactivity timer expires, the RRC connection may be released when the control plane interface signal returns to normal. Alternatively, the UE's RRC connection may be released when the inactivity timer expires if the control plane interface signals do not return normally before the inactivity timer expires.

  Moreover, control plane message exchanges actively triggered by the UE, eg establishment of a new service, may result in exceptions when control plane signaling is sent to the first CN element. In this case, the access network device may release the UE and the following reliability protection measures may be considered.

  First, in order to prevent access of idle UEs, the state of the cells covered by the access network device may be set to the reserved state when the control plane interface signaling is interrupted. This state is used to prohibit access for idle UEs. In this way, exceptions caused by transmission of control plane signaling due to access of idle UEs may be prevented.

  Secondly, a second timer is set in order to prevent a long interruption of control plane signaling from affecting the UE's service experience. The second timer is configured to record the time when the control plane signaling is interrupted and control the timer not to exceed the preset period. The second timer is started when the control plane interface signal is interrupted. When the preset period is reached, the access network device releases all UEs on the S1 link, ie releases the UE's RRC connection. The duration of the second timer may be set according to operator requirements.

  The embodiments described above provide multiple conditions for releasing the UE, such as the expiration of the inactivity timer and the signaling of the control plane interface returning to normal, and in another example, the expiration of the second timer, and It can be seen that the UE initiates the establishment of the control plane connection for the new service. These conditions may be used alone or together. If the conditions are used together, the UE's RRC connection is released when any of the conditions are selectively met. Note that two conditions: control plane interface signaling returning to normal, and the expiration of the second timer are used to control the access network device to release all UEs on the S1 link. On the other hand, two conditions: the expiration of the inactivity timer and the UE initiating the establishment of the control plane in connection for the new service are used to control the access network device to release the associated UE. It

  The following embodiments are described in detail with reference to all the aforementioned release conditions. The following embodiments are merely examples and are not intended to limit the present invention.

  FIG. 4 is a flowchart of a data transmission method according to another embodiment of the present invention. As shown in FIG. 4, the method of this embodiment may include the following steps.

  S401. The access network device acquires the information about the bearer that needs to be established from the first CN element, and establishes the bearer according to the information about the bearer that needs to be established.

  S402. The access network device detects whether the signal of the control plane interface between the access network device and the first CN element is interrupted.

  If the control plane interface signals are not interrupted, normal data transmission may be performed. This is prior art and is not described here, regardless of the essence of the invention. Upon detecting that the control plane interface signal is interrupted, the access network device does not release the RRC connection of the UE to maintain the service continuity of the UE, and performs the following operations.

  S403. The access network device starts a second timer.

  S404. When there is data to be transmitted in the UE's existing service, the established bearer is used to transmit the data to be transmitted in the UE's existing service.

  Note that S404 may occur concurrently with or subsequent to S403.

  In this embodiment, the access network device starts a second timer when it detects that the signal of the control plane interface is interrupted. The second timer period is used to indicate the maximum duration for which the UE maintains the RRC connection when the control plane interface signal is interrupted. When the second timer expires, the access network device releases the RRC connection of the UE and the user plane connection of the UE is disconnected.

  S405. The access network device detects whether the first timer of the UE expires.

  If the first timer of the UE has expired, step S406 is executed. For UEs whose first timer has not expired, step S404 is performed when there is data to be transmitted in the UE's existing services. That is, the data to be transmitted in the existing service of the UE is transmitted by using the established bearer. The first timer of each UE is started by the access network device when the access network device receives the uplink or downlink data of each UE. Furthermore, each time the UE receives uplink or downlink data, the access network device resets the first timer of the UE. The access network device then continues to monitor whether each UE has data to be transmitted or received. If the UE has data to be transmitted or received within the period of the first timer, the access network device resets the first timer of the UE and the first timer starts timing again. If the UE has no data to be transmitted or received for the duration of the first timer of the UE, the access network device releases the RRC connection of the UE.

  In this embodiment, the period of the first timer of each UE needs to be set correctly. If the duration of the first timer is set shorter, the UE's RRC connection is released sooner when the UE has no service, which may cause the UE to frequently make RRC connection setup requests. However, an increase in the amount of normal release of the RRC connection of the UE leads to better network performance indicators, such as the call drop rate obtained through system statistics. If the duration of the first timer is set longer, the UE's RRC connection is released later when the UE has no service, and the UE remains online and occupies radio resources for a longer time. However, a reduction in the amount of UE normal release of RRC connections results in worse network performance indicators, such as call drop rates obtained through system statistics. Therefore, during the setting of the period of the first timer, different periods may be set according to different service requirements.

  S406. The access network device releases the RRC connection of the UE when the first timer expires.

  If the eNB detects that the first timer of any UE expires, the eNB releases the RRC connection of the UE. The first timer of the UE may expire because the UE has no service to be transmitted or because the UE actively leaves the network. In this embodiment, the UE actively leaving the network means that the UE is powered off or the UE is switched to an offline mode. When the UE leaves the network, it triggers a detach procedure in the Non-access stratum (NAS for short), and then a detach request (to release the context and all bearers). detach request) to the first CN element, and the first CN element releases the UE. The NAS procedure requires the UE to interact with the first CN element. The first CN element cannot handle the NAS procedure because the transmission between the access network device and the first CN element is interrupted. Therefore, the NAS procedure expires and the UE retreats to the Evolved Packet System Mobility Management Deregistration (EMM-DEREGISTERED) state. Finally, the first timer of the UE started by the eNB expires because the UE has no data to send.

  In the present embodiment, whether or not the first timer of each UE expires is used as a condition for releasing the RRC connection of each UE. When the UE has no service, the UE's RRC connection can be released in time. That is, the radio resources occupied by the UE can be released, thereby avoiding waste of radio resources.

  S407. The access network device detects whether the control plane interface signal returns to normal.

  When the control plane interface signal returns to normal, step S408 is executed. Step S404 is performed when the control plane interface signal does not return to normal and the UE's existing service still has no data to be transmitted. That is, the data to be transmitted in the existing service of the UE is transmitted by using the established bearer.

  S408. The access network device releases the RRC connection of all UEs on the S1 link.

  Furthermore, after the access network device starts the second timer, the access network device performs the subsequent step S409.

  S409. The access network device detects whether the second timer expires.

  If the second timer has expired, step S408 is executed. If the second timer has not expired, step S404 is performed when the UE's existing service still has data to be transmitted. That is, the data to be transmitted in the existing service of the UE is transmitted by using the established bearer. In this embodiment, a second timer is set to control the time that the UE maintains the user plane connection after the control plane interface signal is interrupted.

  The state of the UE at the access network device is inconsistent with the state of the UE at the first CN element after the control plane interface signaling is interrupted. From the perspective of the access network device, the UE remains connected and the information about the UE remains stored in the access network device. However, from the perspective of the first CN device, the UE is disconnected and idle and the information about the UE stored in the first CN device may be deleted. In order to keep the state of the UE on the access network device consistent with the state of the UE on the first CN device, in the present embodiment, after the access network device detects that the signal of the control plane interface returns to normal, the access The network device releases the RRC connection of the UE on the S1 link.

  It should be noted that in the present embodiment, steps S404, S405, S407, and S409 do not necessarily have to be executed sequentially, but may be executed in parallel.

  In this embodiment, the access network device comprehensively determines whether to release the RRC connection of the UE according to conditions such as the duration of the first and second timers and whether the signal of the control plane interface returns to normal. To consider. Optionally, the access network device may independently comply with any one of the conditions to determine whether to release the RRC connection of the UE. For example, the access network device detects whether the control plane interface signal returns to normal. When the access network device detects that the control plane interface signal returns to normal, the access network device releases the RRC connection of the UE. Alternatively, the access network device detects if the second timer expires. If the access network device detects that the second timer has expired, the access network device releases the RRC connection of the UE.

  Further, in the present embodiment, after detecting that the signal of the control plane interface is interrupted, the access network device sets the state of the cell covered by the access network device to the reserved state. The reserved state is used to prohibit an idle UE from accessing a cell covered by an access network device. The UE in idle state cannot access the cell covered by the access network device because the access network device cannot establish the control plane connection to the first CN device after the signal of the control plane interface is interrupted. In order to prevent the UE in the idle state from accessing the cell, in this embodiment the access network device sets the state of the cell covered by the access network device to the reserved state after the signal of the control plane interface is interrupted. Set. When the UE in idle state learns that the state of the cell is reserved, the UE in idle state no longer tries to access the cell, but chooses to access another cell.

  Further, in this embodiment, if any UE initiates the establishment of the control plane connection for a new service before the control plane interface signal returns to normal, the access network device is responsible for the new service of the UE. , Control plane connection and user plane connection need to be established. The new service of the UE cannot be provided because the control plane interface signal is not returning normally and the access network device cannot establish the control plane connection to the first CN device. In this embodiment, in order to provide a new service for the UE, the access network device releases the RRC connection of the UE so that the UE can access the network through another access network device and the first CN device. In this way, the new services of the UE are unaffected.

  FIG. 5 is a schematic structural diagram of an access network device according to an embodiment of the present invention. The access network device 500 is applied to a communication system, which includes the access network device 500 and a core network device, and the core network device includes a first CN element and a second CN element. The control plane interface is provided between the access network device 500 and the first CN element, and the user plane interface is provided between the access network device 500 and the second CN element. As shown in FIG. 5, the access network device 500 provided in this embodiment includes a processing module 51 and a transmission / reception module 52.

  The processing module 51 is configured to obtain from the first CN element through the control plane interface information about the bearer that needs to be established.

  The processing module 51 is further configured to establish a bearer according to the information about the bearer that needs to be established.

  The sending module 52 is configured to inform the second CN element of the established bearer via the first CN element.

  The transmitting module 52 is further configured to transmit the data to be transmitted within the existing service of the user equipment (UE) by using the established bearer when the control plane interface signal is interrupted.

  Optionally, the processing module 51 starts or resets a first timer when the access network device receives the data of the UE, the first timer being configured to record the inactive period of the UE, the first timer being Upon termination, it is further configured to release the RRC connection of the UE.

  Optionally, the processing module 51 is further configured to detect whether the control plane interface signal returns to normal and release the RRC connection of the UE when the control plane interface signal returns to normal.

  Optionally, the processing module 51 is further configured to start a second timer when the control plane interface signal is interrupted and release the RRC connection of the UE when the second timer expires.

  Optionally, the processing module 51 is further configured to release the RRC connection of the UE when the UE initiates the establishment of the control plane connection for a new service before the control plane interface signal returns to normal.

  Optionally, the processing module 51 sets the state of the cells covered by the access network device to the reserved state when the control plane interface signal is interrupted, the reserved state prohibiting access of the idle UE. It is further configured to be used for.

  It should be noted that the processing module 51 in this embodiment may be a stand-alone processor or may be integrated in the processor of the access network device. Further, the processing module 51 may be stored in the memory of the access network device in the form of program code, and the processor of the access network device calls the program code to perform the functions of the processing module 51. Here, the processor may be a Central Processing Unit (CPU) or an Application Specific Integrated Circuit (ASIC), or is configured to implement this embodiment of the invention. Alternatively, it may be a plurality of integrated circuits. Further, the transmitting unit 52 in this embodiment may be a transmitter of an access network device or a communicator of an access network device, the communicator integrating a transmitting function and a receiving function.

  The access network device in this embodiment may be configured to execute the data transmission method provided in the above embodiments. The specific implementation and technical effects are similar. With reference to the description of the previous embodiments, details are not described here.

  FIG. 6 is a schematic structural diagram of another access network device according to an embodiment of the present invention. The access network device 600 in this embodiment is applied to a communication system, and the communication system includes the access network device 600 and a core network device, and the core network device includes a first CN element and a second CN element. The control plane interface is provided between the access network device 600 and the first CN element, and the user plane interface is provided between the access network device 600 and the second CN element. As shown in FIG. 6, the access network device 600 provided in the present embodiment includes a processor 61, a memory 62, an interface circuit 63, and a system bus 64. The processor 61, the memory 62, and the interface circuit 63 include a system. Memory 62 is configured to store computer-executed instructions and interface circuit 63 is configured to communicate with another device, connected and communicated with each other by using bus 64.

  The processor 61 obtains the information about the bearer that needs to be established by using the interface circuit 63 from the first CN element through the control plane interface, and when the information about the bearer that needs to be established is obtained, the processor 61 is established. The bearer is established according to the information about the required bearer, the established bearer is notified to the second CN element through the first CN element by using the interface circuit 63, and when the signal of the control plane interface is interrupted, the established bearer is established. By using, the user equipment (UE) is configured to transmit data to be transmitted in an existing service.

  Processor 61 is further configured to release the RRC connection of the UE upon determining that any one or a combination of the following release conditions is met. Specifically, it is as follows.

  The first timer is started or reset when the UE's data is received by using the interface circuit 63, the first timer is configured to record the UE's inactive period, and the UE's radio resource control (RRC). ) The connection is released when the first timer expires.

  It is detected whether the control plane interface signal returns to normal, and when the control plane interface signal returns to normal, the RRC connection of the UE is released.

  When the control plane interface signal is interrupted, the second timer is started and when the second timer expires, the UE's RRC connection is released.

  The UE's RRC connection is released if the UE initiates the establishment of the control plane connection for a new service before the control plane interface signaling returns to normal.

  When the control plane interface signaling is interrupted, the state of the cells covered by the access network device 600 is set to the reserved state, which is used to prohibit access for idle UEs.

  It should be noted that the processor 61 of this embodiment may be one processor or may be a collective term of a plurality of processing elements. For example, the processor 61 may be a CPU, or an ASIC, or one or more integrated circuits configured to implement this embodiment of the invention, such as one or more microprocessors (digital signal). processor, DSP), or one or more field programmable gate arrays (FPGA).

  The memory 62 may be one storage device, or may be a generic term for a plurality of storage elements, and is configured to store executable program codes or parameters, data, etc. required for the operation of the access network device. To be done. The memory 62 may include random access memory (RAM), or may include non-volatile memory such as magnetic disk storage or flash.

  The system bus 64 may be an Industry Standard Architecture (ISA) bus, a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The system bus 64 can be classified into an address bus, a data bus, a control bus, and the like. For convenience of presentation, only one bold line is used for the presentation in FIG. 6, but does not indicate that there is one bus or one type of bus.

  The access network device in this embodiment may be configured to execute the data transmission method provided in the above embodiments. The specific implementation and technical effects are similar. With reference to the description of the previous embodiments, details are not described here.

  FIG. 7 is a schematic structural diagram of a communication system according to an embodiment of the present invention. As shown in FIG. 7, the communication system provided in the present embodiment includes an access network device 71 and a core network device 72, and the core network device 72 includes a first CN element 721 and a second CN element 722, and controls. The plane interface is provided between the access network device 71 and the first CN element 721, and the user plane interface is provided between the access network device 71 and the second CN element 722. The access network device 71 may be configured to execute the data transmission method provided in the above embodiments. The specific implementation and technical effects are similar. With reference to the description of the previous embodiments, details are not described here.

  Persons of ordinary skill in the art may understand that all or a part of the steps of the method embodiments may be implemented by a program instructing relevant hardware. The program may be stored in a computer-readable storage medium. When the program runs, the steps of the method embodiments are performed. The aforementioned storage medium includes any medium capable of storing the program code, such as ROM, RAM, a magnetic disk or an optical disk.

  Finally, it should be noted that the above-described embodiments are merely for explaining the technical solution of the present invention, not for limiting the scope of the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can understand the techniques they described in the aforementioned embodiments without departing from the scope of the technical solution of the embodiments of the present invention. It is understood that changes may be made to the technical solutions or equivalent technical replacement of some or all of the embodiments.

500 access network device 51 processing module 52 transmission module 71 access network device 72 core network device 721 first CN element 722 second CN element

Claims (16)

A data transmission method, wherein the method is applied to a communication system, the communication system including an access network device and a core network device, the core network device including a first core network element and a second core network element. A control plane interface is provided between the access network device and the first core network element, and a user plane interface is provided between the access network device and the second core network element, The method is
Obtaining by the access network device from the first core network element through the control plane interface information of a bearer of a user equipment (UE) that needs to be established;
The access network device establishing the bearer according to the information,
Notifying the second core network element of the established bearer through the first core network element by the access network device;
Maintaining a radio resource control (RRC) connection of the UE by the access network device when the control plane interface signal is interrupted;
Including the method. The method is
A step of starting or resetting a first timer by the access network device when the access network device receives the data of the UE, the first timer recording the inactive period of the UE. Step,
Releasing the RRC connection of the UE by the access network device when the first timer expires;
The method of claim 1, further comprising: The method is
Detecting by the access network device whether the signal of the control plane interface returns to normal;
Releasing the RRC connection of the UE when the signal of the control plane interface returns to normal by the access network device;
The method of claim 1, further comprising: The method is
Starting a second timer by the access network device when the signal of the control plane interface is interrupted;
Releasing the RRC connection of the UE by the access network device when the second timer expires;
The method of claim 1, further comprising: The method is
Releasing the RRC connection of the UE by the access network device when the UE starts to establish a control plane connection for a new service before the signal of the control plane interface returns to normal.
The method of claim 1, further comprising: The method is
A step of setting, by the access network device, a state of a cell covered by the access network device to a reserved state when the signal of the control plane interface is interrupted, wherein the reserved state is a UE in an idle state. Steps used to ban access to
The method according to any one of claims 1 to 5, further comprising: The method is
Transmitting, by the access network device, the data of the UE to the second core network element using the established bearer,
The method according to any one of claims 1 to 6, further comprising: An apparatus applied to an access network apparatus, wherein the access network apparatus is applied to a communication system, the communication system includes the access network apparatus and a core network apparatus, and the core network apparatus is a first core network. A control plane interface is provided between the access network device and the first core network element, and a user plane interface includes the access network device and the second core network element. And the device is
Means for obtaining from the first core network element through the control plane interface information about a bearer of a user equipment (UE) and that needs to be established;
Means for establishing the bearer according to the information,
Means for notifying the second core network element of the established bearer through the first core network element;
Means for maintaining radio resource control (RRC) connection of the UE when the control plane interface signal is interrupted;
A device that includes. Means for starting or resetting a first timer when the access network device receives data of the UE, the first timer being arranged to record an inactive period of the UE;
Means for releasing the RRC connection of the UE upon expiration of the first timer;
9. The device of claim 8, further comprising: Means for detecting whether the signal of the control plane interface returns to normal,
Means for releasing the RRC connection of the UE when the signal of the control plane interface returns to normal;
9. The device of claim 8, further comprising: Means for starting a second timer when the signal of the control plane interface is interrupted;
Means for releasing the RRC connection of the UE upon expiration of the second timer;
9. The device of claim 8, further comprising: Means for releasing the RRC connection of the UE if the UE starts to establish a control plane connection for a new service before the signal of the control plane interface returns to normal;
9. The device of claim 8, further comprising: Means for setting a state of a cell covered by the access network device to a reserved state when the signal of the control plane interface is interrupted, the reserved state for prohibiting access of an idle UE Means used for
9. The device of claim 8, further comprising: Means for transmitting data of the UE to the second core network element using the established bearer,
9. The device of claim 8, further comprising:   A communication system comprising the access network device according to any one of claims 8 to 14, a first core network element and a second core network element, wherein a control plane interface is the access network device. A communication system in which a user plane interface is provided between the first core network element and a user plane interface between the access network device and the second core network element.   A program that causes a computer to execute the method according to claim 1.