CN1997216B - Method for user device switching in the long evolving network - Google Patents

Abstract

The invention relates to a long-term evolution network, and discloses a user equipment switching method in the long-term evolution network, so that the switching delay between eNodeBs can be optimized. In the present invention, according to whether it is adjacent to other eNodeBs, the cells subordinate to the eNodeB are divided into adjacent cells and non-adjacent cells. When a UE enters an adjacent cell, the RRC context image of the UE is established on the GW, and the RRC context is established on the adjacent eNodeB through the GW. If the result of the handover decision is that the UE is handed over to the adjacent eNodeB, the RRC context copy in the eNodeB is directly used to allocate radio resources to complete the handover. When the RRC context in the serving eNodeB changes, the image in the GW is updated synchronously, and the copy in the adjacent eNodeB is updated by the GW according to a preset policy. If the UE enters a non-adjacent cell, delete the mirror image in the GW and the copy in the adjacent eNodeB.

Description

User equipment handover method in long term evolution network

technical field

The present invention relates to a long-term evolution network, in particular to a user equipment switching method in the long-term evolution network. the

Background technique

Mobile communication technology has developed rapidly since it entered the second generation of mobile communication (The Second Generation, referred to as "2G") at the end of the 20th century. However, with the increase in the number of users and the continuous improvement of the requirements for business types and performance, 2G gradually shows limitations in data transmission capabilities. Therefore, the third generation of mobile communication (The Third Generation, referred to as "3G") with stronger data transmission capabilities has entered a stage of rapid development, and the field of mobile communication is showing a trend of gradual transition from 2G to 3G. the

While the 3G system is gradually entering commercial use, the industry has already started research on new technologies. Some companies call these new technologies Super 3G (Super 3G) technology, and some companies call it 3.9G technology. The data service transmission rate of 3.9G technology will reach about 100Mbps, and a large number of advanced technologies will be introduced, such as Orthogonal Frequency Division Multiplexing (OFDM for short) and Multiple Input Multiple Output (Multiple Input Multiple Output, short for "MIMO"), etc., these advanced technologies are collectively referred to as 3G evolved technologies in my country, that is, E3G technologies. the

In order to realize the standardization of E3G technology, from the end of 2004, the 3rd Generation Partnership Project (3rd Generation Partnership Project, referred to as "3GPP") and 3GPP2 started the corresponding research work successively. the

With the introduction of high-speed downlink packet access (High Speed Downlink Packet Access, referred to as "HSDPA"), enhanced uplink (Enhanced Uplink) and other enhanced technologies, 3GPP wireless access technology will be very competitive in the next few years of. However, in order to ensure competitiveness for a longer period of time (such as 10 years or longer), 3GPP started the Long Term Evolution (LTE for short) project from the second half of 2004. the

In order to support the hybrid networking during the evolution from 2G to 3G, for the circuit switching domain of the mobile communication system, the 3G standard Universal Mobile Telecommunications System (Universal Mobile Telecommunications System, referred to as "UMTS") stipulates the support of circuit switching domain and packet switching domain services The basic configuration of the public land mobile network (Public Land Mobile Networks, referred to as "PLMN") and interface. the

Generally speaking, the UMTS system consists of User Equipment (UE for short), UMTS Terrestrial Radio Access Network (UTRAN for short), and Core Network (CN for short). ")composition. the

The UTRAN also includes many radio network subsystems (Radio Network Subsystem, referred to as "RNS") connected to the CN. An RNS includes a radio network controller (Radio Network Controller, "RNC" for short) and one or more base stations (NodeB), and each NodeB covers one or more cells. the

In the LTE network, the network structure of NodeB, RNC and CN three-layer nodes of the 3G network is simplified into a two-layer node structure. , "eNodeB" for short) and high-level nodes, such a high-level node is called a Gateway (Gateway, "GW" for short) node, a central node, or an Anchor. the

At the same time, the state of the protocol processing is also simplified, divided into three states, which are offline (LTE-Detached), idle (LTE-Idle) and active (LTE-RRC-Active) states. Specifically, in the LTE-Detached state, the network side does not receive any information from the UE; in the LTE-Idle state there is no RRC connection; in the LTE-RRC-Active state there is an RRC connection. the

In the future LTE network, more services with different requirements will be provided. For some special real-time services, such as video phone (Video Phone), etc., it is necessary to meet the requirements of low packet loss rate. At the same time, in the discussion of the LTE network, due to the use of the shared channel, the soft handover is canceled. Therefore, some companies have proposed some solutions, such as data forwarding (DataForwarding), bicasting (Bi-casting), etc. )wait. However, due to the different characteristics of real-time services and non-real-time services, their requirements are also different. For example, for non-real-time services, the lossless handover solution for data forwarding can fulfill its requirements well; but for real-time services, it is more suitable to use the dual-cast solution. the

In the UMTS R6 system, the hard handover scheme is not assisted by data forwarding or bicast scheme, which will cause certain data loss or interruption delay. ") entities will be reset and parameters will be refreshed. the

In the discussion of the existing LTE scheme, the dual-cast scheme proposed on the basis of the GW by using the RLC function is shown in FIG. 2 . the

Establish the RRC management relationship between eNodeB 2 and eNodeB 4 and the UE, and the source eNodeB2 maintains the RRC management function, that is, the RRC management entity located in the eNodeB 2 maintains the RRC context (Context) of the UE; GW maintains no RRC connection Under the UE management, that is to maintain the UE context. The location of the processing entity is shown in Figure 3. the

Before the eNodeB handover occurs, the RRC context is saved by the possible handover candidate target eNodeB 4, but the GW does not save a mirror copy of the RRC context. The behavior of the RRC context in the candidate target eNodeB 4 is maintained by the source eNodeB 2. the

In practical application, the above solution has the following problems: the handover delay between eNodeBs in the LTE network is relatively large. the

The main reason for this situation is that the GW cannot control the bicasting to the source eNodeB and the target eNodeB because there is no RRC context of the UE in the GW. The process of selecting a candidate target eNodeB is maintained, so the selection process is complicated and the handover delay is large. the

Contents of the invention

In view of this, the main purpose of the present invention is to provide a user equipment handover method in a long term evolution network, so that the inter-eNodeB handover delay in the LTE network can be optimized. the

In order to achieve the above object, the present invention provides a user equipment handover method in a long term evolution network, comprising the following steps:

A. When the user equipment enters an adjacent cell where the serving eNodeB is adjacent to other eNodeBs, the serving eNodeB transfers the copy of the radio resource control context of the user equipment to the adjacent eNode of the adjacent cell through the gateway node B. The copy of the radio resource control context is copied from the original copy of the radio resource control context, and is updated in real time by the gateway node according to a preset policy;

B. If the user equipment is handed over to the adjacent eNodeB, use the radio resource control context copy in the adjacent eNodeB to complete the handover. the

Wherein, the step A further includes the following sub-steps:

When the user equipment enters an adjacent cell where the serving eNodeB is adjacent to other eNodeBs, the serving eNodeB establishes a mirror image of the radio resource control context of the user equipment at the gateway node;

The gateway node transfers a copy of the radio resource control context image to a neighboring eNodeB of the neighboring cell. the

In addition, in described method, also comprise following steps:

When the radio resource control context of the user equipment changes, the serving eNodeB synchronously updates the mirror image of the radio resource control context in the gateway node. the

In addition, in described method, also comprise following steps:

After the image in the gateway node is synchronously updated by the serving eNodeB, the gateway node updates the radio resource control context copy in the adjacent eNodeB according to a preset policy. the

In addition, in described method, also comprise following steps:

When the user equipment leaves the adjacent cell, delete the radio resource control context copy in the adjacent eNodeB adjacent to the adjacent cell. the

In addition, in described method, also comprise following steps:

When the user equipment enters a non-adjacent cell that is not adjacent to other evolved Node Bs from the adjacent cell, delete the radio resource control context image of the user equipment in the gateway node. the

In addition in described method, described step B also comprises following sub-step:

During the handover process of the user equipment to the neighboring eNodeB, the gateway node performs bicasting by using the radio resource control context image of the user equipment stored locally. the

In addition, in the described method, the switching process in the step B also includes the following sub-steps:

The serving eNodeB serves as the source eNodeB to make a decision on handover between eNodeBs, and notifies the target eNodeB;

The target evolved Node B uses the radio resource control context copy of the user equipment to perform radio resource allocation and notifies the source evolved Node B of the radio resource preparation result;

If the radio resource preparation result is a failure, the source eNode B aborts the handover decision;

If the radio resource preparation result is successful, the source evolved Node B sends a handover command to the user equipment;

The user equipment switches the service to the target eNodeB according to the handover command, and sends a handover confirmation message to the target eNodeB;

After receiving the handover confirmation message, the target eNodeB notifies the source eNodeB to release related resources. the

In addition, in the method, the information exchange between the eNBs is relayed by the gateway node. the

Through comparison, it can be found that the main difference between the technical solution of the present invention and the prior art is that the cells under the eNodeB are divided into adjacent cells and non-adjacent cells according to whether they are adjacent to other eNodeBs. When the UE enters an adjacent cell, the GW establishes the The RRC context of the UE is mirrored, and the RRC context copy is established in the adjacent eNodeB through the GW. If the handover decision result is that the UE is handed over to the adjacent eNodeB, the RRC context copy in the eNodeB is directly used to allocate radio resources to complete the handover. the

When the RRC context in the serving eNodeB changes, the image in the GW is updated synchronously, and the copy in the adjacent eNodeB is updated by the GW according to a preset policy (not necessarily updated synchronously in real time). If the UE enters a non-adjacent cell, delete the mirror image in the GW and the copy in the adjacent eNodeB. the

The difference in this technical solution brings obvious beneficial effects, that is, because the RRC context copy is established in each eNodeB that may become the handover target in advance, the RRC context copy can be directly used when initiating the actual handover, It saves the time needed in the prior art to temporarily send the RRC context copy from the source eNodeB to the target eNodeB after the handover decision, makes the handover more rapid, and can especially meet the requirements of real-time services. the

Because the mirror image updated synchronously with the RRC context in the source eNodeB is established in the GW, the mirror image in the GW can be directly used to implement the dual-cast technology. the

Because the RRC context copy in the adjacent eNodeB is updated through the preset policy, and the RRC context copy with a little deviation can still perform the handover work, so this policy does not require the real-time synchronous update method, which can reduce the communication pressure of the GW . the

By releasing the RRC context image or copy in the GW and the adjacent eNodeB in time, the resource occupation of the GW and the adjacent eNodeB can be reduced. the

Description of drawings

Fig. 1 is a schematic diagram of the layered structure of the LTE network in the prior art;

FIG. 2 is a schematic diagram of a UE handover method in an LTE network in the prior art;

Fig. 3 is a schematic diagram of the position of the LTE network processing entity in the prior art;

FIG. 4 is a flowchart of a UE handover method in an LTE network according to a first embodiment of the present invention;

Fig. 5 is a schematic diagram of the position of UE in the LTE network according to the first embodiment of the present invention;

Fig. 6 is the handover method flowchart of UE in the LTE network according to the second embodiment of the present invention;

Fig. 7 is a schematic diagram of a location of a UE in an LTE network according to a second embodiment of the present invention. the

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings. the

For the eNodeB and GW two-layer node structure of the LTE network, before handover between eNodeBs, the image of the RRC context of the UE is transferred to the GW, and a copy of the image is delivered to the adjacent eNodeB according to the cell where the UE is located, realizing Preprocessing of over-the-air assets before switching. the

The UE handover method in the LTE network according to the first embodiment of the present invention is shown in Figure 4, wherein, the UE moves from the adjacent cell C09 of the source eNodeB 1 to the adjacent cell C01 of the target eNodeB 3 through the adjacent cell C01, as shown in Figure 5 . the

In step 401, the UE has service data transmission with the source eNodeB 1, and enters the adjacent cell C01 from the non-adjacent cell C09 (C01 is adjacent to the eNodeB 3). the

In step 402, once the UE enters the adjacent cell C01, the source eNodeB 1 sends the RRC context of the UE to the GW, and the GW creates a mirror of the RRC context, and the mirror is synchronized with the RRC context of the UE in the source eNodeB 1 renew. the

In step 403, the copy of the RRC context is sent to the target eNodeB 3 through the image established by the GW, and the copy of the RRC context in the adjacent eNodeB is updated through a preset strategy. the

Because the RRC context copy with a slight deviation can still perform the handover work, this strategy does not require a real-time synchronous update method, which can reduce the communication pressure on the GW. It should be noted that in the present invention, "mirror" means that it is exactly the same as the original and updated in real time, and "copy" means copied from the original but the device can only guarantee real-time update as much as possible. the

If the UE enters the adjacent cell C03, since C03 is adjacent to eNodeB 3 and eNodeB 4, the GW will send a copy of the UE's RRC context to the two adjacent eNodeBs at the same time. the

In step 404, as the UE moves into the adjacent cell C08 of the target eNodeB 3, when a handover is required, the source eNodeB 1 sends a handover decision to the GW to notify the handover. the

In step 405, the GW forwards the handover decision for handover to the target eNodeB 3. the

In step 406, after receiving the decision, the target eNodeB 3 allocates radio resources according to the RRC context copy of the UE, and notifies the GW of the success (or failure) of the allocation. The RRC context copy is established in the eNodeB that may become the handover target in advance, so that the RRC context copy can be used directly when initiating the actual handover, which saves the need for the prior art to temporarily send the RRC context copy from the source eNodeB to the target eNodeB after the handover decision The required time makes switching more rapid, especially meeting the requirements of real-time services. the

In step 407, the GW notifies the source eNodeB 1 of the result of successful (or failed) allocation, and implements a dual-cast mechanism at the same time, that is, simultaneously sends the service data of the UE to the source eNodeB 1 and the target eNodeB 3. Because the mirror image updated synchronously with the RRC context in the source eNodeB 1 is established in the GW, the mirror image in the GW can be directly used to implement the dual-cast technology. the

In step 408, the source eNodeB 1 sends a handover command to the UE for allocation success according to the notification. In addition, if the notification is allocation failure, the source eNodeB 1 gives up the handover. the

In step 409, after receiving the switching command, the UE switches the service to the target eNodeB 3. the

In step 410, while switching services, the UE sends a switching confirmation message to the target eNodeB3. the

In step 411, when the target eNodeB 3 receives the message from the UE, it sends a resource release notification to the GW. the

In step 412, the resource release notification is forwarded by the GW to the source eNodeB 1, and the source eNodeB 1 releases the radio resource between itself and the UE according to the notification, and completes the handover. the

The UE handover method in the LTE network according to the second embodiment of the present invention is shown in FIG. 6 , wherein, the UE moves from the adjacent cell C01 of the source eNodeB 1 to the non-adjacent cell C04 via the adjacent cell C02, as shown in FIG. 7 . the

When the UE is in the adjacent cell C01, according to the above embodiment, when the UE enters the adjacent cell C01, the RRC context image of the UE has been established in the GW, and a copy of the image has been established in the eNodeB 3. the

Step 601 is similar to step 401 . the

In step 602, the UE leaves the adjacent cell C01, and the eNodeB 1 sends a notification to the GW that the UE leaves the adjacent cell C01. the

In step 603, the GW sends an instruction to delete the copy to the eNodeB 3 according to the notification. The eNodeB 3 is made to release the copy in the adjacent eNodeB in time, which can reduce the resource occupation of the adjacent eNodeB. the

In step 604, the UE enters the adjacent cell C02 (C02 is adjacent to the eNodeB 4), and the eNodeB1 sends a notification to the GW that the UE enters the adjacent cell C02. the

In step 605, after receiving the notification, the GW sends a copy of the image to eNodeB 4 according to the image of the RRC context of the UE, and eNodeB 4 establishes the copy. the

In step 606, the GW implements a dual-cast mechanism to send service data to eNodeB 1. the

In step 607, GW sends service data to eNodeB 4. the

Step 608 and step 609 are similar to step 602 and step 603 respectively, both of which are in the case of leaving an adjacent cell. the

In step 610, the UE enters the non-adjacent cell C04 (C04 is not adjacent to other eNodeBs), and eNodeB 1 sends a notification to the GW that the UE enters the non-adjacent cell C04. According to the notification, the GW deletes the mirror image of the RRC context of the UE. By releasing the RRC context image in the GW in time, the occupation of GW resources can be reduced. the

Although the present invention has been illustrated and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the present invention. The spirit and scope of the invention. the

Claims (9)

1. the method for user device switching in the long-term evolving network is characterized in that, comprises following steps:

A, when the adjacent abutting subdistrict of the subscriber equipment service of entering enode b and other enode b, this service enode b by gateway node with the Radio Resource of this subscriber equipment control context copy be delivered to this abutting subdistrict in abutting connection with enode b, described Radio Resource control context copy is duplicated by Radio Resource control context original paper and obtains, and presets tactful real-time update by the gateway node basis;

If it is described in abutting connection with enode b that the described subscriber equipment of B switches to, then use this to finish switching in abutting connection with the Radio Resource control context copy in the enode b.

2. the method for user device switching in the long-term evolving network according to claim 1 is characterized in that, described steps A further comprises following substep:

When the adjacent abutting subdistrict of the subscriber equipment service of entering enode b and other enode b, the Radio Resource that this service enode b is set up this subscriber equipment at described gateway node is controlled contextual mirror image;

Described gateway node with the copy of described Radio Resource control context mirror image be delivered to this abutting subdistrict in abutting connection with enode b.

3. the method for user device switching in the long-term evolving network according to claim 2 is characterized in that, also comprises following steps:

When the Radio Resource control context of described subscriber equipment changed, described service enode b upgraded the mirror image of this Radio Resource control context in described gateway node synchronously.

4. the method for user device switching in the long-term evolving network according to claim 3 is characterized in that, also comprises following steps:

After the mirror image in the described gateway node was upgraded synchronously by described service enode b, this gateway node was according to presetting the described Radio Resource control context copy in enode b of policy update.

5. the method for user device switching in the long-term evolving network according to claim 2 is characterized in that, also comprises following steps:

When described subscriber equipment leaves described abutting subdistrict, the described Radio Resource control context copy in enode b that deletion is adjacent with this abutting subdistrict.

6. the method for user device switching in the long-term evolving network according to claim 5 is characterized in that, also comprises following steps:

When described subscriber equipment when described abutting subdistrict enters not with the adjacent non-adjacent sub-district of other enode b, delete the Radio Resource control context mirror image of this subscriber equipment in described gateway node.

7. the method for user device switching in the long-term evolving network according to claim 3 is characterized in that, described step B also comprises following substep:

In the described process of switching in abutting connection with enode b, described gateway node uses the Radio Resource control context mirror image of local this subscriber equipment of preserving to carry out two broadcasting at described subscriber equipment.

8. according to the method for user device switching in each described long-term evolving network in the claim 1 to 7, it is characterized in that the handoff procedure among the described step B also comprises following substep:

Described service enode b is made the judgement of switching between enode b as the source enode b, and the notification target enode b;

Described target enode b uses the Radio Resource control context copy of described subscriber equipment to carry out wireless money distribution and Radio Resource is prepared result notification source enode b;

Be failure if described Radio Resource is prepared the result, then described source enode b is abandoned switch decision;

If it is successfully that described Radio Resource is prepared the result, then described source enode b sends switching command to described subscriber equipment;

Described subscriber equipment switches to the target enode b according to switching command with business, and sends switching authentic information to the target enode b;

After the target enode b was received switching authentic information, the notification source enode b discharged related resource.

9. the method for user device switching in the long-term evolving network according to claim 8 is characterized in that, the information interaction between the described enode b is by described gateway node transfer.

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