CN106899582A - A kind of LTE Advanced Pro systems realize the protocol configuration method of LWA functions - Google Patents

Abstract

The present invention requests protection of a protocol configuration method for realizing the LWA function of the LTE-Advanced Pro system. First, the data is offloaded at the high-level PDCP layer and transmitted to the SeNB. At this time, the SeNB is also an AP and AC secondary cell that can support WLAN. In the secondary cell, the link structure of the LAN needs to be designed as a LAN that can identify PDCP PDUs and radio bearer identifiers. This can solve the problem that there is no logical channel in the WLAN MAC, and define a new adaptation layer between the PDCP layer and the Between the MAC layers, it can add a certain bit of ID indication to the PDCP packet transmitted in the downlink and an indication that can distinguish between LTE transmission and WLAN transmission, so that it is convenient for the UE to identify the transmission of the respective data. When the data is transmitted to the high-level PDCP on the UE side, the two types of wirelessly transmitted data are submitted to the upper layer in sequence through the LWA function. In this way, the transmission of the entire service is completed through the LWA.

Description

A protocol configuration method for realizing LWA function in LTE-Advanced Pro system

technical field

The present invention relates to the technical field of 5G mobile communication, and aims to describe a new control access method of a 5G heterogeneous network.

Background technique

With the rise of smart devices and data-intensive services, more and more people are working on new network architectures and communication solutions. In the latest LTE-A Pro standard, system enhancements for aggregation of various radio access technologies for 5th generation (5G) mobile communication and standardization of wireless communication are studied. Among them, LTE-U, LTE-LAA, LWA and multi-link TCP are all preselected solutions for the integration of these two wireless technologies. One of the current research topics is LTE-WLAN aggregation, that is, the design structure of LWA, which aims to realize unlicensed frequency bands. Bandwidth aggregation of WLAN and licensed-band LTE, and simultaneous use of LTE radio access and WLAN radio access, will improve user experience and handle the explosive volume of data traffic. LWA technology is introduced as part of the fifth generation (5G) of mobile communications. An important technical challenge is the design of existing network architectures. In particular, the structure for LTE-WLAN aggregation should be designed such that the Quality of Service (QOS) level of the Evolved Packet System (EPS) bearer is guaranteed even when each EPS bearer is transmitted over WLAN radio. The most basic requirements should include: (1) The overall aggregation structure designed must be backward compatible with existing LTE-A specifications and WLAN guidelines. (2) The aggregated data transmission achieved must not have any impact on the use in existing WLANs. In order to meet these requirements, a design structure of LWA is finally given. After analyzing the advantages and disadvantages of various designs in the protocol stack, this design structure is selected as the expected structure for the standardization of LTE-WLAN aggregation in 3GPP.

The structural design of LTE-WLAN aggregation should be based on the application scenario as shown in Figure 1. Now describe the current challenges with this design from either the sender side or the receiver side point of view.

First, on the sending side, encryption is applied to the EPS bearer. Therefore, the WLAN MAC cannot identify the QOS level of the EPS bearer because the PDCP PDU is encrypted, meaning the Type of Service (ToS) field in the IP header is encrypted. In the local area network used, the local area network technology that supports the QOS identification function should be used. And the function of supporting offload bearer and aggregation on the sending side.

Second, on the receiving side, no LCID is added to the WLAN PDU received by the WLAN. Therefore, the receiver cannot identify the corresponding RB and deliver the WLAN PDU to the corresponding EPS bearer. For the downlink, the receiving side is the UE, and it is the destination node. The UE needs to deliver the received data to the application layer. Therefore, failing to identify the EPS bearer will cause disordered arrival of PDCP data packets, and the transmission type of the service cannot be identified. However, from a protocol point of view, PDCP (Packet Data Convergence Protocol Layer) is the protocol endpoint of the radio bearer, so it is better to perform demapping from AC (Access Category) to EPS (Evolved Packet System) bearer. For uplink, the receiving side is eNB, but it is not the destination. Therefore, SeNB should perform de-mapping from AC to EPS bearer, and then deliver each EPS bearer to the core network through the GTP tunnel associated with each EPS bearer. Therefore, a method for AC to EPS bearer demapping without LCID (Logical Channel Identifier) is needed.

Contents of the invention

The present invention aims at the above-mentioned problems and challenges. The MeNB supports the LWA function through software upgrade, and uses the MeNB network element and the SeNB (WT) to establish a standard connection between the control plane and the bearer plane. The MeNB and SeNB must support the Split Bearer and Switch Bearer bearer allocation methods to realize flexible configuration of LTE and WLAN. A protocol configuration method for implementing LWA function in the LTE-Advanced Pro system is proposed to complete the integration of two network resources and bandwidth aggregation, thereby improving customer experience and greatly improving the transmission performance of the entire mobile network. Technical scheme of the present invention is as follows:

A kind of protocol configuration method that LTE-Advanced Pro system realizes LWA function, it comprises the following steps:

101. Configure the normal packet data convergence protocol PDCP on the macro cell base station MeNB on the sending side, and enable the macro cell base station MeNB and the secondary cell base station SeNB to support two bearer allocation methods: Split Bearer and Switch Bearer. In the macro cell base station MeNB Encrypt the IP packet, add the PDCP header to the IP packet, and then offload it to the secondary cell base station as a PDCPPDUPDCP protocol data unit;

102. Then implement QOS configuration in the WLAN, and add an adaptation function in the base station of the secondary cell. The main function of the adaptation layer is to insert and analyze EtherType and bearer ID, so that the UE can distinguish the WLAN message from the split bearer of the LWA; and in the PDCP layer The virtual gateway VGW is deployed between WLAM MAC to establish a virtual network, and the receiving side demaps the received AC access category to the corresponding EPS bearer through the virtual network;

103. On the receiving side, the UE used for the downlink and the SeNB used for the uplink identify each EPS bearer from the AC based on the LWAAP cellular local area aggregation access point module; then gradually submit it to the PDCP layer and complete it at the adaptation layer Data splitting and aggregation processing, and finally data processing at the application layer.

Further, the PDCP PDU in step 101 is forwarded to the auxiliary cell via the Xw interface, and the receiving side can receive the PDCP PDU from LTE-A and WLAN. In order to ensure that the PDCP PDU is delivered to the application layer in order, the PDCP layer will be based on the sequence of all PDUs Number reordering, in order to achieve the correct transmission of data.

Further, the IP packet in the PDCP layer is offloaded to the SeNB as a PDCP PDU through the Xw interface by using the currently mature dual link technology, and the IP packet reaches the corresponding RLC layer in the SeNB and is transmitted to the VGW.

Further, the IP layer is deployed at the entrance of the VGW, where the IP flow is divided into four QOS levels, including Video (VI), Voice (V0), Best Effort (BE) and Background (BK) four parts .

Further, the protocol used by the WLAN is IEEE802.11e. IEEE802.11e is one of the WLAN types supporting QOS-aware packet processing. In the 802.11MAC layer, 802.11e adds a Qos function.

Further, the SeNB sets the ToS field as an IP header, and other fields in the IP header are reserved for

Realization of virtual gateway VGW.

Further, the step 103 includes the following processing steps:

Step 1) Connection configuration process: first, the paging configuration request initiated by the UE side requests to establish a connection with the macro base station, and reports its own connection status, including whether it is in the processing range of the WLAN;

Step 2) Secondary cell addition process: The macro cell base station sends a signaling to the secondary cell base station, including EPS bearer information and WLAN information, and requests the primary cell and the secondary cell to complete the dual link of the terminal. If the request is accepted, the secondary cell The base station sends a response to the macro cell base station, indicating that it agrees to the aggregation of LTE-WLAN;

Step 3) RRC connection reconfiguration process: RRC configures parameters on the MeNB side of the macro cell base station, and sends the information status of SeNB to the UE to notify the parameters, and notifies the UE of the completion of the MeNB configuration;

Step 4) Random access process: UE performs random access process for uplink timing synchronization, SeNB cell establishes connection with UE through WLAN after receiving information about UE;

Step 5) Finally realize the offloading of data, the PDCP PDU that is offloaded by the MeNB side is passed to the UE as a WLAN PDU after MAC address resolution, and after demapping the resource blocks of the MAC layer of the WLAN to the virtual gateway, the PDCP layer The data from LTE and the data from WLAN are aggregated through the data aggregation technology, and delivered to the application layer.

Further, the interface between the MeNB and the SeNB can be in two forms: an Xw interface and a GTP tunnel can be deployed between the MeNB and the SeNB, and the GTP-U protocol among them can realize data transmission between the radio access network and the core network. The transmission of user data packets can be transmitted in any format in IPv4, IPv6 or PPP.

Advantage of the present invention and beneficial effect are as follows:

The main innovation of the present invention is to overcome the problem that the data cannot be recognized by the MAC layer after the data is encrypted during the splitting process, insert and analyze EtherType and bearer ID through the added adaptation layer, realize error-free transmission, and complete two kinds of network resources Convergence and bandwidth aggregation to improve customer experience. With LWA, the LTE data payload can be separated, some traffic will be transmitted through WLAN, and the rest will be transmitted through LTE-A itself, thus greatly improving the transmission performance of the entire mobile network.

Description of drawings

Fig. 1 is the schematic diagram that the present invention provides preferred embodiment LWA networking;

Figure 2 is a flow chart of LWA network air interface protocol design;

Figure 3 is a link structure design diagram based on the entire network;

Figure 4 is a flow chart of specific implementation steps.

detailed description

The technical solutions in the embodiments of the present invention will be described clearly and in detail below with reference to the drawings in the embodiments of the present invention. The described embodiments are only some of the embodiments of the invention.

The technical scheme that the present invention solves the above-mentioned technical problem is,

Combined with the deployment of unlicensed spectrum newly proposed in recent years, in the state of licensed assisted access, using the ample spectrum resources of unlicensed spectrum will greatly improve the cellular data capacity. Therefore, the present invention utilizes the existing technology The specification proposes a network architecture design that integrates LTE-A and WLAN technologies, as shown in Figure 2.

In this solution, we configure normal PDCP at the PDCP layer to enable it to implement functions such as encryption and integrity protection at the PDCP layer. Here, we encrypt the IP packets, add PDCP headers to the IP packets, and then offload them to the secondary cell as PDCP PDUs. In order to implement QOS configuration in WLAN, we need to add an adaptation function in the auxiliary cell. The main role of the adaptation layer is to insert and parse the EtherType and bearer ID so that the UE can distinguish the WLAN message from the LWA splitbearer. Since the hybrid automatic retransmission (HARQ) function cannot be implemented in the WLAN MAC, this will cause data loss, and the adaptation layer can provide this function here.

PDCP PDUs are forwarded to the secondary cell via the Xw interface. The receiving side can receive PDCP PDUs from LTE-A and WLAN. In order to ensure that PDCP PDUs are delivered to the application layer in order, the PDCP layer will reorder based on the sequence numbers (SN) of all PDUs to achieve correct data transmission. In MeNB, the PDCP layer is configured with normal PDCP. The IP packet in the PDCP layer is offloaded to the SeNB as a PDCP PDU through the Xw interface using the current mature dual link technology. It reaches the corresponding RLC layer in the SeNB and is delivered to the VGW. The virtual gateway (VGW) is deployed between the PDCP layer and the WLAM MAC to establish a virtual network. The design of this virtual gateway is equivalent to the function of the adaptation layer. The receiving side can demap the received AC to the corresponding AC through the virtual network. EPS bearer. The key point here is that the IP layer is deployed at the entrance of the VGW, where the IP flow is divided into four QOS levels to adapt to the transmission of services. QOS configuration in WLAN MAC is performed by using the Type of Service (ToS) field in the IP header. Here, the protocol used by the WLAN is IEEE802.11e, and IEEE802.11e is one of WLAN types that support QOS-aware packet processing. At the 802.11MAC layer, 802.11e adds the QoS function. Its distributed control mode can provide stable and reasonable quality of service, while the centralized control mode can more flexibly support multiple quality of service policies, making the transmission of voice, video and other services more efficient. smooth.

The above-mentioned SeNB addition request is an important signaling. The SeNB identifies the QOS level and QCI value of each EPS bearer by receiving the signaling. Therefore, SeNB can set ToS field as IP header. Other fields in the IP header are left for VGW implementation. The success of the present invention is mainly due to the setting of the adaptation layer and the virtual gateway, through which the receiving side can demap the received AC to the corresponding EPS bearer.

For LTE-WLAN aggregation, this patent provides the specific structure of the entire network architecture, as shown in Figure 3, according to the WLAN technology provided by the IEEE802.11e standard, the QOS processing of the EPS bearer in the WLAN MAC is realized. The PDCP normal transmission mode is configured on the sending side (for the MeNB for the downlink and the UE for the uplink), so that the input IP packets are processed by the virtual gateway and then delivered to the WLAN MAC for classification and identification. The WLAN MAC then does AC classification based on the ToS field in the IP header. The receiving side (UE for downlink and SeNB for uplink) recognizes each EPS bearer from AC based on LWAAP module. Then it is gradually submitted to the PDCP layer according to the structure in Figure 2, and the data splitting and aggregation processing are completed at the adaptation layer, and finally the data processing at the application layer is realized.

In the design, the interface between MeNB and SeNB can be in two forms: Xw interface and GTP tunnel can be deployed between MeNB and SeNB, and the GTP-U protocol can realize data exchange between the radio access network and the core network. For transmission, user data packets can be transmitted in any format in IPv4, IPv6 or PPP, which facilitates data processing between the two. There is a feedback between MeNB and SeNB. For dual links, only one feedback about flow control is needed, but when replacing SeNB with indoor WLAN, some feedback information needs to be added, including WLAN bandwidth and throughput. Because the WLAN may be under different bandwidth conditions, letting the MeNB know the bandwidth and throughput of the WLAN is beneficial to the control and offloading of the WLAN by the MeNB, which is also an important factor for realizing LWA.

The implementation of the present invention will be described in more detail below by combining the information transmission process between the three transmission points in the mobile network architecture of the present invention, as shown in Figure 4:

Step 1) The first thing you need is the connection configuration of the authorized spectrum in LTE-A. The paging configuration request initiated by the UE is the same as the mobile cellular network of LTE-A. To establish a connection with the macro base station, you need to select your own connection. Enter cell, operator and other information, and report its own connection status, including whether it is within the management range of WLAN, so as to know whether LWA communication is possible.

Step 2) According to the information reported by the UE, when LTE-WLAN aggregation communication can be performed, the secondary cell with a WLAN access point needs to be added, and the primary cell sends a signaling to the secondary cell, including EPS bearer (such as: QOS attribute) and WLAN and other information (such as: MAC address of UE). The request here is similar to the mature dual-link technology between the primary cell and the secondary cell. If the request is accepted, the secondary cell will send confirmation and feedback information to the primary cell, indicating that it agrees to the aggregation of LTE-WLAN.

Step 3) After the connection reconfiguration is realized through RRC, RRC is required to configure parameters on the MeNB side, so as to realize the flow control of the system network, and send the information status of SeNB to UE to notify the parameters. The completion of the MeNB configuration is notified to the UE.

Step 4) Next, realize the random access procedure. According to the configuration information sent from the MeNB side, the UE performs the random access procedure for uplink timing synchronization. After receiving the information about the UE, the SeNB cell establishes a connection with the UE through the WLAN.

Step 5) After the connection configuration of the entire network is completed, the PDCP PDU sent by the MeNB side through the offload bearer is delivered to the MAC layer of the UE side as a WLAN PDU after being loaded and analyzed by the virtual gateway. After the resource blocks passing through the MAC layer of the WLAN are demapped to the virtual gateway, the data from the LTE and the data from the WLAN are aggregated by the PDCP layer through the data aggregation technology, and then delivered to the application layer.

The working principle of this patent is:

In this patent, the LTE-A data is used as the carrier of WLAN AP, and after part of the data is transmitted to the terminal or network end through the WLAN network, it is aggregated at the high level to achieve efficient transmission of a large number of services. The aggregation of licensed frequency bands in LTE-A realizes the integration of two wireless communication technologies. This LWA method enables the MeNB side and the UE side to quickly transmit data to peers through offloading and aggregation. LWA is used as Part of the 5G solution is to assist operators to realize the integration and optimization of LTE and WLAN network resources, which is to realize future high-demand data services.

The above embodiments should be understood as only for illustrating the present invention but not for limiting the protection scope of the present invention. After reading the contents of the present invention, skilled persons can make various changes or modifications to the present invention, and these equivalent changes and modifications also fall within the scope defined by the claims of the present invention.

Claims (8)

1. a kind of protocol configuration method that LTE-Advanced Pro system realizes LWA function, is characterized in that, comprises the following steps: 101. On the sending side, the macro cell base station MeNB normally configures the packet data convergence protocol layer PDCP, and enables the macro cell base station MeNB and the secondary cell base station SeNB to support two bearer allocation methods: Split Bearer and Switch Bearer. In the macro cell base station MeNB Encrypt the IP packet, add the PDCP header to the IP packet, and then offload it to the base station of the secondary cell as a protocol data unit PDCP PDU of the packet data convergence protocol; 102. Then implement QOS configuration in the WLAN, and add an adaptation function in the secondary cell base station SeNB. The main function of the adaptation layer is to insert and analyze the EtherType and bearer ID, so that the UE can distinguish the WLAN message from the split bearer of the LWA; and in PDCP The virtual gateway VGW is deployed between the layer and the WLAM MAC to establish a virtual network, and the receiving side demaps the received access category AC to the corresponding EPS bearer through the virtual network; 103. On the receiving side, the UE used for the downlink and the SeNB used for the uplink identify each EPS bearer from the AC based on the access point LWAAP module of cellular local area aggregation; then gradually submit it to the PDCP layer and complete it at the adaptation layer Data splitting and aggregation processing, and finally data processing at the application layer. 2. The protocol configuration method for realizing the LWA function in the LTE-Advanced Pro system according to claim 1, wherein the PDCP PDU in step 101 is forwarded to the auxiliary cell via the Xw interface, and the receiving side can receive from LTE-A and WLAN Receive PDCP PDU, in order to ensure that the PDCP PDU is delivered to the application layer in order, the PDCP layer will reorder based on the sequence numbers of all PDUs to achieve correct data transmission. 3. LTE-Advanced Pro system according to claim 2 realizes the protocol configuration method of LWA function, it is characterized in that, the IP grouping in the PDCP layer utilizes present ripe dual link technology to be unloaded to as PDCP PDU by Xw interface SeNB, some IP packets arrive at the corresponding RLC layer in the SeNB and are transmitted to the VGW. 4. LTE-Advanced Pro system according to claim 3 realizes the protocol configuration method of LWA function, it is characterized in that, described IP layer is deployed at the entrance of VGW, and wherein IP flow is divided into four QOS levels, subsection Including Video, Voice, Best Effort and Background four parts. 5. The protocol configuration method for realizing the LWA function in the LTE-Advanced Pro system according to any one of claims 1-4, wherein the protocol used by the WLAN is IEEE802.11e, and IEEE802.11e supports QOS perception grouping One of the types of WLANs that are processed, at the 802.11MAC layer, 802.11e adds the Qos function. 6. The protocol configuration method for implementing the LWA function in the LTE-Advanced Pro system according to any one of claims 1-4, wherein the SeNB sets the ToS field as an IP header, and other fields in the IP header are reserved for virtual Gateway VGW implementation. 7. according to the protocol configuration method that the LTE-Advanced Pro system according to one of claim 1-4 realizes LWA function, it is characterized in that, described step 103 comprises the following processing steps: Step 1) Connection configuration process: first, the paging configuration request initiated by the UE side requests to establish a connection with the macro base station, and reports its own connection status, including whether it is in the processing range of the WLAN; Step 2) Secondary cell addition process: The macro cell base station sends a signaling to the secondary cell base station, including EPS bearer information and WLAN information, and requests the primary cell and the secondary cell to complete the dual link of the terminal. If the request is accepted, the secondary cell The base station sends a response to the macro cell base station, indicating that it agrees to the aggregation of LTE-WLAN; Step 3) RRC connection reconfiguration process: RRC configures parameters on the MeNB side of the macro cell base station, and sends the information status of SeNB to the UE to notify the parameters, and notifies the UE of the completion of the MeNB configuration; Step 4) Random access process: UE performs random access process for uplink timing synchronization, SeNB cell establishes connection with UE through WLAN after receiving information about UE; Step 5) Finally realize the offloading of data, the PDCP PDU that is offloaded by the MeNB side is passed to the UE as a WLAN PDU after MAC address resolution, and after demapping the resource blocks of the MAC layer of the WLAN to the virtual gateway, the PDCP layer The data from LTE and the data from WLAN are aggregated through the data aggregation technology, and delivered to the application layer. 8. The protocol configuration method for realizing the LWA function in the LTE-Advanced Pro system according to claim 7, wherein the interface between the MeNB and the SeNB can be in two forms: Xw can be deployed between the MeNB and the SeNB Interface and GTP tunnel, the GTP-U protocol can realize data transmission between the wireless access network and the core network, and user data packets can be transmitted in any format in IPv4, IPv6 or PPP.