WO2003037011A1 - A method for realize communication directly between base stations - Google Patents

Abstract

The invention disclose a method for communication directly on data and signaling between base stations. It includes creating a logic interface IuNB for interconnection between base stations, the interface is used to support signaling and data transmission between the two base stations, and accomplish management and maintaining of transmission network between base-stations, business management and interface resource management of transmission channels; The process as below: first, using above-mentioned interface, build a logic link between two base stations, second, utilizing the logic link, accomplish the transmission and management functions of data and signaling; Last, release the logic link between two base stations. The said method also includes establishing protocol stack of the IuNB interface control panel and the consumer panel. The invention can set up the link that can be communicating directly between base stations, achieve the exchange of signaling and data directly, it also can lighten the data processing burden of RNC, eliminate the influence of the Iub/Iur interface delays, consequently it improved the efficiency of the radio communication system. The invention will pay a important role in promoting the evolvement of UTRAN structure and functions.

Description

 Method for implementing direct communication between base stations

 The present invention relates to a transmission technology of a wireless communication network, and specifically proposes a method for directly communicating data and signaling between base stations of a wireless communication system.

Background technique

In the Universal Terrestrial Radio Access Network (UTRAN) system, because entities of different nodes have different functions to be completed and processed data, different interfaces using different protocols are applied. For example, the interface between the radio network controller (RNC) and SGSN / MSC (GPRS service support node / mobile switching center) is an Iu interface, and the interface control protocol is RNAP (radio network application part); the interface between RNC and RNC Is the RNC interface (Iur) interface in UTRAN, and the interface control protocol is the Radio Network Subsystem Application Part (RNSAP); the interface between the RNC and the base station (NodeB) is the base station interface (Iub interface) in UTRAN, the interface control protocol It is the base station application part (NBAP) of the WCDMA system; the air interface of the user equipment (UE) and the UTRAN network is the Uu interface; for the uplink / downlink, the transmission channels of the signaling and data flow according to the above interface are: ： MSC / SGSN——Serving RNC—— RNC (optional) —— NodeB introduces Internet Protocol (IP protocol) transmission in the 5th version (R5) phase of the 3rd Generation Partnership Project (3GPP) standard. Hang directly on the edge router of the IP network, for example: RNC and NodeB are directly connected to the edge router respectively. The data stream on the Iub interface is identified by "User Datagram Protocol (UDP) port number + IP address". According to the flow. In this structure, the transmission between the RNC and the NodeB changes from the original hierarchical relationship to an equivalent entity, and free communication can be achieved between the NodeB and between the NodeB and the RC. However, most of the current transmission control functions in the UTRAN system are performed by the RC. An RNC needs to manage multiple NodeBs. Not only is the signaling and data processing delays caused by the heavy load, but the Iub interface also causes signaling and data processing. There is also a problem of resource constraints such as buffers and common channels. In order to overcome the bottleneck caused by the centralized RNC processing, some RNC functions need to be moved down to the NodeB to improve the efficiency of the system, such as the MAC-hs entity is moved down. However, as some functional entities of the RNC are moved down to NodeB, the demand for direct communication between NodeBs will increase, such as high-speed downlink packet access (HSDPA), fast cell selection (FCS), and distributed PDU queues to replace the concentration in RNC. PDU queue, the synchronization information of PDU queue will be frequently transmitted between NodeBs. It can be seen that with the gradual transfer of RNC functions to NodeB, the control relationship between RNC and NodeB is also diminishing, and the process control between UTRAN entities is gradually shifted from centralized management to distributed management. If the current information exchange between NodeBs is still The RNC does this. Not only does the transmission path become longer, but it is still constrained by the delay of the Iub / Iur interface, which will inevitably lead to a decrease in system efficiency.

Summary of the Invention

 An object of the present invention is to provide a method for implementing direct communication of data and signaling between base stations. The method can significantly reduce the data processing load of RC, eliminate the impact of Iub / Iur interface delay, and thereby improve the efficiency of a wireless communication system. .

To achieve the above object, the method for implementing direct communication between base stations provided by the present invention includes: (1) establishing a logical interface (IuNB) for inter-base station interconnection, which supports signaling negotiation on radio resources required for a communication link between base stations (NodeB), and supports data frame communication between base stations;

 (2) Establish a logical link between the two base stations, complete the signaling and data transmission between the two base stations, and complete the management and maintenance of the transmission network between the base stations, the service management of the transmission channel, and the management of the interface resources ;

 (3) After completing the functions described in step (2) above, release the link between the base stations. The method further includes creating a protocol stack for the IuNB interface control plane and user plane. The control plane protocol stack includes 6 layers. The first layer uses the physical layer (L1) protocol, the second layer uses the data link layer (L2) protocol, the third layer uses the Internet protocol (IP protocol), and the fourth layer uses Stream control transmission protocol (SCTP protocol), the fifth layer uses the signaling user adaptation protocol (SUA protocol), and the sixth layer uses the base station to base station application part (BBAP) protocol.

 The fifth layer of the above control plane protocol stack includes two sublayers. The first sublayer uses the MTP3 user adaptation layer (M3UA, MTP3: third layer of the message transmission part) protocol, and the second sublayer uses the signaling connection control part (SCCP). )protocol.

 The user plane protocol stack includes five layers, the first layer uses the L1 protocol, the second layer uses the L2 protocol, the third layer uses the IP protocol, the fourth layer uses the User Datagram Protocol (UDP) protocol, and the fifth layer uses IuNB frame protocol.

Because the present invention defines an IuNB interface for direct communication between base stations, and also defines its control plane and user plane protocol stacks, it provides a more convenient channel for information transmission between base stations, and enables base stations to communicate between base stations. Establish a direct communication link This method can significantly reduce the data processing load of the RNC, eliminate the impact of the Iub / Iur interface delay, and improve the efficiency of the wireless communication system. At the same time, the control plane signaling carried by the luNB interface will play an important role in promoting the evolution of UTRA structure and functions in order to increase the amount of control information for NodeB.

BRIEF DESCRIPTION OF THE DRAWINGS

 Figure 1 is a structural diagram of a distributed UTRAN system;

 FIG. 2 is a location diagram of the interface according to the present invention in a UTRAN system;

 3 is a flowchart of an embodiment of a method according to the present invention;

 4 is a protocol stack of the luNB interface according to the present invention;

 5 is a process of establishing and releasing a user plane link based on the luNB interface of the present invention;

 FIG. 6 is a process diagram of distributed link management implemented in the FCS process of HSDPA by applying the present invention.

detailed description

 The invention is described in further detail below with reference to the drawings.

In the UTRAN system, in order to reduce the load of RNC data processing and push the function of the RNC down to the base station, the present invention establishes a logical interface luNB capable of realizing the interconnection of the base stations between the physical base station and the base station in the UTRAN. An embodiment of a method for implementing direct communication between base stations according to the foregoing interface according to the present invention is shown in FIG. 3. Step 1: Establish a logical interface luNB for interconnection between base stations, which should follow the following principles: first, the interface should be an open interface; second, the interface should support signaling and data transmission between the two base stations; third, the interface should It is a point-to-point logical connection interface between two base stations, regardless of the specific physical connection. The logical interface Iu B interconnected between base stations has the following characteristics: 1) Supports signaling negotiation of radio resources required for communication links between NodeBs. 2) Supports data frame communication between base stations. The data frame formats (including HS-DSCH) currently supported by the NodeB are supported by the IuNB interface data frames.

 The IuNB interface established in accordance with the above principles and features has the following functions: it can support signaling and data transmission between two base stations, can complete the management of the transmission network, the service management of the transmission channel, and the management of the IuNB interface resources;

 To complete the above functions, it is necessary to create the protocol stack of the IuNB interface control plane and user plane. Refer to Figure 4. The control plane protocol stack in this embodiment includes 6 layers. The first layer uses the L1 protocol, the second layer uses the L2 protocol, the third layer uses the IP protocol, the fourth layer uses the SCTP protocol, and the fifth layer uses the SUA protocol. 笫Layer 6 uses the BBAP protocol.

 In addition to the SUA protocol, the fifth layer of the control plane protocol stack may also adopt a structure including two sublayers. The first sublayer uses the M3UA (MTP3 User Adaptation Layer, MTP3: Information Transfer Part 3) protocol. The second sublayer uses the SCCP (Signaling Connection Control Part) protocol.

 The user plane protocol stack includes five layers, the first layer uses the L1 protocol, the second layer uses the L2 protocol, the third layer uses the IP protocol, the fourth layer uses the UDP protocol, and the fifth layer uses the IuNB protocol.

The above BBAP is a wireless network layer protocol of IuNB on the control plane. It can be extended based on the existing NBAP protocol, and some optional IEs (information elements) supporting IuNB transmission can be added. The control plane wireless transport layer protocol uses SCTP streams to distinguish it, which is consistent with the existing BAP signaling transmission. Step 2: Use the interface provided in the above step 1 to establish a logical link between the two base stations, and use the logical link control to complete the signaling and data transmission between the two base stations, and the management and transmission of the transmission network. Channel service management and management functions of the IuNB interface resources.

 Step 3. After completing the functions described in step 2 above, release the logical link between the base stations. Refer to Figure 5 for the process of establishing and releasing IuNB links in steps 2 and 3 above.

 Among them, establishing a logical link between two base stations can be implemented by the following steps: Refer to FIG. 5.

 When the base station 1 needs to establish an IuNB link with the base station 2, first the base station 1 sends a request to establish a logical link (InterNodeB Connection Request) to the base station 2; then the base station 2 sends a response to establish a link to the base station 1 according to the above request. (InterNodeB Connection Setup); Finally, after receiving the response, the base station 1 allocates link resources, and sends a message (InterNodeB Connection Setup Complete) to the base station 2 to complete the establishment of the IuNB link between the two base stations.

 The release of the logical link between the two base stations can be achieved by the following steps: When the link between the two base stations needs to be released, first the base station 1 sends a message requesting the release of the link to the base station 2 (InterNodeB Connection Release); then 2 The base station releases the resources related to the link according to the message, and sends a link release complete message (InterNodeB Connection Release Complete) to the base station 1. Finally, after receiving the message that the link is released, the base station 1 releases itself IuNB link resources, thereby completing the release of the logical link between the base stations.

The following uses the IuNB interface provided by the present invention to perform HSDPA FCS (high-speed An embodiment of the distributed link management process of fast cell selection in downlink packet access) further explains the present invention. Refer to Figure 6.

 In the Iu B-based HSDPA FCS process described in FIG. 6, when a new cell joins the active set, the RNC (radio network controller) sends to the base station to which the new cell belongs the IP addresses and cell IDs of the base stations to which all cells in the active set belong. (Identification) number of radio link setup request (Radio Link setup request), the new cell through the control of the IuNB interface to all cells in the active set for the signaling broadcast including the IP address of the base station to which the new cell belongs and the cell ID number (InterNodeB Connection request), and the base station to which the primary cell belongs establishes a link connection signaling (InterNodeB Connection setup) via the control plane of the IuNB interface to instruct the base station to which the new cell belongs to allocate necessary link resources. The base station to which the new cell belongs allocates the allocated link resources, that is, the data ports, to the base station to which the primary cell belongs by using the signaling of the IuNB control plane link completion (②) (InterNodeB Connection setup complete). The IuNB data link is established.

 After the base station to which the new cell belongs establishes the IuNB link, it reports to the R C that the radio link establishment is complete. The RNC then informs the UE (user equipment) to update the current active set stored on the UE side.

 After establishing the IuNB link, the base station to which the primary cell belongs sends the updated "Active Set Routing Table Synchronization" message to the base stations to which all slave cells belong via the established IuNB data link, and then the base station to which the slave cell belongs controls the slave cell. Updates to the active set routing table. This process and subsequent cell synchronization information sent from the primary cell to the secondary cell belong to the content of "IuNB interface data transmission" in (3) in the figure.

When a cell exits the active set, the resources related to the current cell in the cell are released. Source. It further judges whether it is the last cell in the NodeB to which it belongs in the current active set according to the active set, and if so, it also notifies the NodeB to release the resources related to the IuNB data link.

 The RNC first informs the UE to update the active set, and notifies the exiting cell to remove the link between the Iub (base station interface in UTRAN) and the IuNB interface.

First, the RNC notifies the UE to update the activation set. When the UE updates the activation set, the RNC sends a request to release the radio link to the exiting cell, and the exiting cell uses the IuNB control plane link release signaling ④ (InterNodeB Connection release) to notify the activation set. All cells in the network release link resources related to themselves. After all cells return to the exiting cell through IuNB control, a confirmation message of link release completion (InterNodeB Connection release complete) is returned, and the exiting cell releases resources related to the active set in the cell, and then notifies the RNC that the link is removed.

Claims

Rights request  1. A method for implementing direct communication between base stations, including:  (1) Establish a logical interface (Iu B) for interconnection between base stations, which supports signaling negotiation of wireless resources required for communication links between base stations (NodeB), and supports data frame communication between base stations;  (2) Establish a logical link between the two base stations, complete the signaling and data transmission between the two base stations, and complete the management and maintenance of the transmission network between the base stations, the service management of the transmission channel, and the management of the interface resources ;  (3) After completing the functions described in step (2) above, the logical link between the stations. 2. The method for implementing direct communication between base stations according to claim 1, further comprising: creating a protocol stack for the control plane and user plane of the IuNB interface.  3. The method for implementing direct communication between base stations according to claim 1, characterized in that: the control plane protocol stack includes 6 layers, the first layer uses a physical layer (L1) protocol, and the second layer uses data Link layer (L2) protocol, the third layer uses the Internet Protocol (IP protocol), the fourth layer uses the Flow Control Transmission Protocol (SCTP protocol), the fifth layer uses the Signaling User Adaptation Protocol (SUA protocol), and the sixth layer The base station to base station application part (BBAP) protocol is used. 4. The method according to claim 3, wherein the fifth layer of the control plane protocol stack includes two sub-layers, and the first sub-layer uses an MTP3 user adaptation layer (M3UA, MTP3 : The third layer) protocol of the message transmission part, and the second sub-layer adopts the signaling connection control part (SCCP) protocol. 5. The method for implementing direct communication between base stations according to claim 1, characterized in that: the user plane protocol stack includes five layers, the first layer uses the L1 protocol, the second layer uses the L2 protocol, and the third layer uses IP protocol, the fourth layer uses the User Datagram Protocol (UDP) protocol, and the fifth layer uses the IuNB frame protocol.  6. The method for implementing direct communication between base stations according to claim 1, wherein the establishing a logical link between two base stations further comprises the following steps:  (61) The base station 1 sends a request for establishing a logical link to the base station 2;  (62) The base station 2 sends a response to establish a link to the base station 1 according to the above request;  (63) 1 The base station allocates link resources after receiving the response, and after the link resources are successfully allocated, sends a link establishment message to the base station 2 to complete the establishment of a logical link between the two base stations. The allocation fails, and a link establishment failure message is sent to the base station 2, and the message includes a corresponding failure reason.  7. The method for implementing direct communication between base stations according to claim 1, wherein the releasing the logical link between the two base stations further comprises the following steps:  (71) The base station 1 sends a message requesting to release the link to the base station 2;  (72) The base station 2 releases resources related to the link according to the message, and sends a message that the link is released to the base station 1;  (73) After receiving the link release completion message, the base station 1 releases its own link resource resources, thereby completing the logical link release between the base stations.