WO2011082522A1

WO2011082522A1 - Method and device for service switching in wireless relay network

Info

Publication number: WO2011082522A1
Application number: PCT/CN2010/070034
Authority: WO
Inventors: 杨涛
Original assignee: 上海贝尔股份有限公司; 阿尔卡特朗讯
Priority date: 2010-01-06
Filing date: 2010-01-06
Publication date: 2011-07-14
Also published as: CN102598790A; CN102598790B

Abstract

The present invention relates to a method and device for service switching in a wireless relay network. According to an embodiment in the present invention, a method for switching the service of a user equipment (UE) in a relay node of a wireless communication network is provided. Said method includes the following steps: A. identifier information used for identifying optional access nodes and quality information reflecting channel quality of the access connections between the optional access nodes and the UE are received from the UE; B. one or more nodes meeting predetermined conditions are selected from said optional access nodes as candidate target nodes. By using the method and device provided by the present invention, good end-to-end communication performance can be guaranteed in the process of selecting a target node, and system signaling overhead can be controlled in a reasonable range, thereby saving system resources.

Description

Method and device for service switching in wireless relay network

The present invention relates to wireless communication technologies, and more particularly to a method and apparatus for service switching in a wireless relay network. Background technique

In the Long Term Evolution Advanced (LTE-A), Type I trunks were adopted as the most important technology to improve system performance. In the same macro cell, there may be dozens of Type I relay nodes. Then a user equipment may face a situation where there are multiple nodes that satisfy the rules for service node selection processing defined by the 8th edition of the Long Term Evolution Project (LTE) protocol standard (release 8). According to the eighth edition of the LTE protocol standard, the serving node is responsible for selecting a target node based on the Reference Signal Received Power (RSRP) of each potential candidate reported by the user equipment and selecting a reference therefrom. One of the signals receiving power is the largest as the target node. In the relay operation scenario, there are two connections between the user equipment and its donor evolved Node B (the donor eNB), that is, the backhaul ling and the service between the donor evolved Node B and the serving relay node. An access connection between the relay node and the user equipment. Therefore, end-to-end communication performance is determined by the overall quality of the access and backhaul connections. According to the current eighth edition of the LTE protocol standard, the target node is selected only based on the report of the user equipment, and the report of the user equipment can only indicate the channel condition of the access connection. However, the quality of the access connection does not mean that the quality of the backhaul connection is good. Especially in the case of carrier aggregation, different relay nodes may work on different carrier components, resulting in different backhaul connection quality. Moreover, the quality of the backhaul connection is subject to factors such as fading, variations in interference, and load conditions. Therefore, selecting a target node based only on the prior art cannot ensure end-to-end communication performance.

Such a technical solution has been proposed: The donor evolved Node B broadcasts information about the quality of all its backhaul connections to all the relay nodes it controls, so that each relay node can comprehensively consider the quality and access of the backhaul connection. Connection quality base Select the target node based on it. However, such a scheme will result in a large amount of signaling overhead, thereby wasting system resources. Summary of the invention

In order to overcome the above-mentioned drawbacks in the prior art, the present invention proposes a technical solution for service switching in a wireless relay network.

The wireless relay network in the present invention includes three network elements: a base station, a relay node, and a user equipment. Several terms used in the present invention are defined as follows and are used uniformly in the following: Access Node: A node that communicates with a user equipment via a hop connection. In the wireless relay network of the present invention, the access node may be a base station or a relay node.

Access connection: The connection between a user equipment and the access node it serves. Backhaul connection: The connection between an access node and its associated base station, its donor base station.

Target node: A new access node that will be served by a user device when it is handed off.

According to a first aspect of the present invention, there is provided a method of switching a service of a user equipment in a relay node of a wireless communication network, comprising the steps of: A. receiving an optional identification from the user equipment Identification information of the access node and quality information reflecting channel quality of the access connection between the optional access node and the user equipment; B. selecting one of the optional access nodes that satisfies a predetermined condition Or multiple nodes as candidate target nodes.

According to a second aspect of the present invention, there is provided a method of switching a service of a user equipment in a base station of a wireless communication network, comprising the steps of: i. receiving information about a user from a jurisdictional relay node Identification information of the device for identifying the candidate target node and quality information reflecting the channel quality of the access connection between the candidate target node and the user equipment; ii. according to the user equipment, the candidate target node End-to-end communication link quality to make decisions about the target node; iii. Notifying the relay node of the decision regarding the target node.

According to a third aspect of the present invention, a relay section in a wireless communication network is provided The first switching device that switches the service of the user equipment in the point includes: a receiving device, configured to receive identification information from the user equipment for identifying the optional access node, and reflect the optional connection The quality information of the channel quality of the access connection between the ingress node and the user equipment; the first determining means, configured to select one or more nodes that meet the predetermined condition from the optional access node as the candidate target node .

According to a fourth aspect of the present invention, there is provided a second switching apparatus for switching a service of a user equipment in a base station of a wireless communication network, comprising: a second receiving apparatus, configured to receive a relay node from a jurisdiction Having, for the user equipment, identification information for identifying a candidate target node and shield information reflecting a channel quality of the access connection between the candidate target node and the user equipment; second determining means, configured to: Determining a decision about the target node according to the end-to-end communication link quality of the user equipment, the candidate target node; and notifying means for notifying the relay node of the decision about the target node.

By using the method and apparatus provided by the present invention, good end-to-end communication performance can be ensured in the process of selecting a target node, and system signaling overhead can also be controlled within a reasonable range, thereby saving system resources. DRAWINGS

The system will be better understood with reference to the figures and description below. The components in the figures are not necessarily drawn to scale, but rather are used to illustrate the principles of a typical model. Throughout the drawings, like reference characters have

1 shows a block diagram of a system of a wireless communication system in accordance with one embodiment of the present invention;

2 shows a flow chart of a method for switching a service of a user equipment in a relay node of a wireless communication network, in accordance with one embodiment of the present invention;

3 is a flow chart showing a method of switching a service of a user equipment in a base station of a wireless communication network according to an embodiment of the present invention;

4 is a block diagram showing the structure of a first switching device for switching a service of a user equipment in a relay node of a wireless communication network according to an embodiment of the present invention; FIG. 5 is a block diagram showing the structure of a second switching device for switching the service of one user equipment in a base station of a wireless communication network according to an embodiment of the present invention. detailed description

1 shows a block diagram of a system of a wireless communication system in accordance with one embodiment of the present invention. The base station 10, 20, 30, as well as relay nodes 11, 12, 21, and user equipment 90 are shown. The relay nodes 11 and 12 are under the jurisdiction of the base station 10, and provide relay services for downlink services from the base station 10 and uplink services from the user equipment. The relay node 21 is under the jurisdiction of the base station 20, and is a downlink service from the base station 20 and from The uplink service of the user equipment provides a relay service.

According to an embodiment of the present invention, the wireless communication network conforms to the LTE-A protocol standard, and the base stations in the network, such as the base stations 10, 20, 30, are all evolved Node Bs, and the relay nodes in the network, such as the relay node 11, 12, including type I relay nodes. Both evolved Node B and Type I relay nodes have their respective cell-specific reference signals.

In one of the above embodiments, the base station 10 is a donor base station of the user equipment 90, and the user equipment 90 is connected to the switching center through the base station 10; at least the end-to-end communication link between the base station 10 and the user equipment 90 includes at least A two-hop connection in which the relay node 11 serves as an access node of the user equipment 90. When the user equipment 90 initiates a handoff, its access node and its donor base station, i.e., the relay node 11 and the base station 10, are typically required to complete the handoff.

2 is a flow chart showing a method of switching a service of a user equipment in a relay node of a wireless communication network, in accordance with one embodiment of the present invention. As shown, the method includes two steps S1 1 and S12. Without loss of generality, the communication link including the base station 10, the relay node 11, and the user equipment 90 will be described as an example.

When the user equipment 90 initiates a handoff, the selection process of the target node is initiated. User equipment 90 will receive signals from neighboring nodes and report information about the optional access node to its access node, i.e., relay node 11. The information about the optional access node reported by the user equipment 90 generally includes an identification letter identifying the optional access node and a channel quality reflecting the access connection between the optional access node and the user equipment 90. Shield volume information. In step S11, the relay node 1 1 will receive identification information from the user equipment 90 for identifying the optional access node and a channel reflecting the access connection between the optional access node and the user equipment 90. Quality quality information.

In step S12, the relay node 1 1 selects one or more nodes satisfying the predetermined condition from the selectable access nodes as candidate target nodes.

Specifically, for example, without limitation, optional access nodes reported by user equipment 90 include relay node 12, relay node 21, and base station 30. In step S12, the relay node 11 will select a candidate target node from among these optional access nodes.

According to an embodiment of the present invention, the quality information of the channel quality in the step S 1 1 reflecting the access connection between the optional access node and the user equipment 90 includes the optional access received by the user equipment 90. The reference signal of the reference signal of the node receives power.

Those skilled in the art should understand that the quality information reflecting the channel quality of the access connection between the optional access node and the user equipment 90 may also include a Received Signal Strength Indicator (RSI) and/or a reference. Signal Received Quality (RSRQ). According to different system settings, the quality information may include any one or more of a reference signal received power, a received signal strength indicator, and a reference signal received quality. There may be different restrictions on the reference signal transmission power of the base station and the relay node. Therefore, when the optional access node includes both the base station and the relay node, the reference signal transmission may also be included when determining the candidate target node in step S12. The difference in power factor. Of course, the user equipment may also count the difference of the reference signal transmission power when reporting the information about the optional access node.

According to an embodiment of the present invention, the predetermined condition in step S12 includes: the reference signal received power of the optional access node at the user equipment 90 exceeds a predetermined threshold. In other words, all of the selectable access nodes whose reference signal received power at the user equipment 90 exceeds a predetermined threshold are determined by the relay node 11 as candidate target nodes. There may be more than one candidate target node. For example, when the reference signal received power of the relay node 12, the relay node 21, and the base station 30 at the user equipment 90 exceeds a predetermined value, all three nodes are determined by the relay node 11 to be handed over by the user equipment 90. Candidate target node.

According to another embodiment of the present invention, the predetermined condition in step S12 includes: The reference signal received power of the optional access node at the user equipment 90 is higher than the reference signal received power of the user equipment 90 by any other optional access node. In other words, there is only one candidate target node, and the relay node 11 will determine the optional access node with the highest reference signal received power of the user equipment 90 as the candidate target node.

According to an embodiment of the present invention, after step S12, the relay node 1 1 further needs to perform a corresponding subsequent operation according to the specific situation of the candidate target node.

According to an embodiment of the invention, there is only one candidate target node determined in step S12 and the node is a base station, such as base station 30. Then, the relay node 1 1 directly determines the unique candidate target node, that is, the base station 30, as the target node, and sends the identification information used to identify the base station 30 to the base station to which the relay node 1 1 belongs, that is, Its donor base station 10 facilitates switching the service of the user equipment 90 to the base station 30. Since when there is only a unique candidate target node and the node is a base station, it is obvious that the node and the user equipment 90 will have optimal end-to-end communication performance, so the relay node 1 1 can directly determine the target node. And thus the overhead of transferring information between the relay node 11 and its donor base station 10 can be reduced.

When the candidate target nodes are all base stations, the relay node 1 1 can already learn the end-to-end communication performance between all the candidate target nodes and the user equipment 90 according to the quality information received in step S1 1 , so the relay node 1 1 The attribution of the target node can be determined without the assistance of the base station 10, and the overhead of transmitting information between the relay node 1 1 and its donor base station 10 can also be reduced. According to another embodiment of the present invention, there are a plurality of candidate target nodes determined in step S12 and are all base stations. Next, the relay node 1 1 will select the target node based on the quality information received in step S1 1. For example, but not limited to, the quality information includes reference signal received power, and the relay node 1 1 determines the candidate target node having the highest received power of the reference signal as the target node. Next, the relay node 1 1 may also transmit identification information for identifying the target node to the base station 10 in order to switch the service of the user equipment 90 to the target node.

When the candidate target node includes the relay node, the relay node 11 does not know the end-to-end communication performance between all the candidate target nodes and the user equipment 90, so the attribution of the target node cannot be determined. According to an embodiment of the present invention, the candidate target node determined in step S12 includes at least another relay node, such as relay node 12 and / Or relay node 21. Then, the relay node 11 transmits the identification information of all the candidate target nodes and the quality information of the channel quality reflecting the access connection between the candidate target node and the user equipment 90 to the base station to which the relay node 1 1 belongs, that is, Its donor base station 10. Next, the attribution of the target node will be determined by the donor base station 10 of the user equipment 90.

3 is a flow chart showing a method of switching a service of a user equipment in a base station of a wireless communication network, in accordance with one embodiment of the present invention. As shown, the method includes three steps S21, S22 and S23. Without departing from the general description, the communication link including the base station 10, the relay node 1 1 and the user equipment 90 will be described as an example.

In step S21, the base station 10 will receive the identification information for identifying the candidate target node from the relay node 1 1 with respect to the user equipment 90 and the channel reflecting the access connection between the candidate target node and the user equipment 90. Quality quality information.

In step S22, base station 10 will make a decision regarding the target node based on the end-to-end communication link quality associated with user equipment 90 and the candidate target node.

In step S23, the base station 10 notifies the relay node 11 of the decision regarding the target node.

According to an embodiment of the present invention, in step S21, the base station 10 receives the identification information of the plurality of candidate target nodes and the quality information, such as the identification information of the relay node 12, the relay node 21, and the base station 30, and the quality information.

Then in step S22, the base station 10 will determine the target node based on the end-to-end communication link quality involving the three candidate target nodes, respectively. There are three end-to-end communication links involved: the first is the end-to-end communication link from the user equipment 90 to the relay node 12 to the base station 10, and the second is the user equipment 90 to the relay node 21 to the base station 20. The end-to-end communication link, the third is the end-to-end communication link of the user node 90 to the base station 30. There may be more than one hop connection between the relay node 12 and the base station 10. The relay node 21 and the base station 20 may also be connected by more than one hop. First, the base station 10 needs to determine the quality of the three end-to-end communication links. The donor base station of the first end-to-end communication link is the base station 10, and therefore, the base station 10 can easily obtain sufficient information in the cell under its jurisdiction to determine the quality of the end-to-end communication link. The donor base station of the second end-to-end communication link is the base station 20, and the quality information received by the base station 10 from the relay node 11 only relates to the access connection of the user equipment 90 to the relay node 21, therefore, the base station 10 still needs to Exchanging information with base station 20 to determine The quality of the second end-to-end communication link. The donor base station of the third end-to-end communication link is a base station 30, but it only includes a one-hop connection, and the quality information received by the base station 10 from the relay node 11 can already reflect the downlink of the third end-to-end communication link. Link quality. In time division duplex (TDD) systems, the upstream channel and the downstream channel are generally considered to be reciprocal. Therefore, in the time division duplex system, the base station 10 can determine the quality of the third end-to-end communication link based only on the quality information received from the relay node 11. Those skilled in the art should understand that the factors determining the quality of the end-to-end communication link may generally include one or more of the following: end-to-end transmission delay, end-to-end average retransmission times. Optionally, the base station 10 determines the candidate target node that optimizes the quality of the end-to-end communication link as the target node. Then the decision about the target node includes the identification information of the target node.

Then, in step S23, the base station 10 notifies at least the identity information of the target node to the relay node 11. Next, the relay node 11 can notify the user equipment 90 of the identification information of the target node to perform the corresponding handover.

According to still another embodiment of the present invention, in step S21, the base station 10 receives only the identification information of one candidate target node and the quality information, such as the identification information of the relay node 21 and the quality information.

Then, in step S22, the base station 10 determines whether the relay node 21 is suitable as a target node to serve the user equipment 90 according to the end-to-end communication link quality of the user equipment 90 to the relay node 21 to the base station 20. Accordingly, the decision regarding the target node includes information indicating whether the relay node 21 is the target node.

Next, in step S23, the base station 10 transmits information indicating whether the relay node 21 is a target node to the relay node 11.

Next, the relay node 1 1 may transmit information indicating whether the relay node 21 is the target node to the user equipment 90. If the relay node 21 is confirmed as the target node, the handover is performed, and the service of the user equipment 90 is carried by the end-to-end communication link of the user equipment 90 to the relay node 21 to the base station 20. If the relay node 21 is not the target node, the existing communication link is maintained, or the selection process of the target node is started again.

According to an embodiment of the present invention, the shield information reflecting the channel quality of the access connection between the candidate target node and the user equipment 90 in step S21 is included by the user equipment. The received reference signal received power of the reference signal sent from the candidate target node is 90. Those skilled in the art will appreciate that the quality information reflecting the channel quality of the access connection between the candidate target node and the user equipment 90 may also include the received signal strength indicator and/or the reference signal reception quality. The quality information may include any one or more of a reference signal received power, a received signal strength indicator, and a reference signal received shield according to different system settings. The reference signal transmission power of the base station and the relay node may have different restrictions. Therefore, when the candidate target node includes both the base station and the relay node, the reference signal transmission power difference may also be included in determining the target node in step S22. A factor. Of course, the user equipment may also account for the difference in the reference signal transmission power when reporting the information about the optional access node.

Figure 4 is a block diagram showing the structure of a first switching device for switching the service of a user equipment in a relay node of a wireless communication network, in accordance with one embodiment of the present invention. As shown, the first switching device 100 includes a first receiving device 101 and a first determining device 102. The first switching device 100 is typically disposed in the relay nodes 11, 12, 21.

The first receiving device 101 is operative to perform step Sl1 in the aforementioned method. Taking the communication link including the base station 10, the relay node 11, and the user equipment 90 as an example, the first receiving device 101 in the relay node 11 will receive the identification information from the user equipment 90 for identifying the optional access node. And quality information reflecting the channel quality of the access connection between the optional access node and the user equipment 90.

The first determining means 102 is operative to perform step S12 of the aforementioned method. Taking the communication link including the base station 10, the relay node 11, and the user equipment 90 as an example, the first determining means 102 in the relay node 11 will select one or more of the optional access nodes that satisfy the predetermined condition. The node acts as a candidate target node.

Figure 5 is a block diagram showing the structure of a second switching device for switching the service of a user equipment in a base station of a wireless communication network, in accordance with one embodiment of the present invention. As shown, the second switching device 200 includes a second receiving device 201, a second determining device 202, and a notifying device 203. The second switching device 200 is typically disposed in the base stations 10, 20, 30.

The second receiving device 201 is configured to perform step S21 in the foregoing method. Including base stations 10. The communication link of the relay node 11 and the user equipment 90 is taken as an example. The second receiving device 201 in the base station 10 will receive the identification information about the candidate target node from the relay node 1 1 regarding the user equipment 90. And shield amount information reflecting the channel quality of the access connection between the candidate target node and the user equipment 90.

The second determining means 202 is operative to perform step S22 of the aforementioned method. Including base stations

10. The communication link of the relay node 1 1 and the user equipment 90 is taken as an example, and the second determining means 202 in the base station 10 will make according to the quality of the end-to-end communication link involving the user equipment 90 and the candidate target node. The decision about the target node.

The notifying means 203 is for performing step S23 in the aforementioned method. Taking the communication link including the base station 10, the relay node 1, and the user equipment 90 as an example, the notifying means 203 in the base station 10 notifies the relay node 1 1 of the decision regarding the target node.

The device referred to in the present invention may be implemented by a software function module, may also be implemented by a hardware module, or may be implemented by a combination of software and hardware.

Those skilled in the art will appreciate that the above-described embodiments are illustrative and not limiting. Other variations of the disclosed embodiments can be understood and effected by those skilled in the <RTIgt; In the claims, the word "comprising" does not exclude other means or steps. The indefinite article "a" does not exclude a plurality. order of. Any reference signs in the claims should not be construed as limiting the scope of the invention. The functions of the various parts appearing in the claims can be implemented by a single hardware or software module. The mere fact that certain technical features are present in different sub-claims does not mean that these technical features are not combined to achieve a beneficial effect.

Claims

Claim

A method for switching a service of a user equipment in a relay node of a wireless communication network, comprising the steps of:

A. receiving, from the user equipment, identification information for identifying an optional access node and quality information reflecting a channel quality of an access connection between the optional access node and the user equipment;

B. Select one or more nodes that satisfy the predetermined condition from the selectable access nodes as candidate target nodes.

2. The method according to claim 1, wherein the method further comprises the steps of:

C1. If there is only one candidate target node and the node is a base station, the node is determined as a target node, and identification information for identifying the target node is sent to the base station to which the relay node belongs, so as to The service of the user equipment is switched to the target node.

3. The method according to claim 1, wherein the method further comprises the steps of:

C2. If the candidate target node includes at least another relay node, the identification information of the candidate target node and the quality information of the channel quality reflecting the access connection between the candidate target node and the user equipment Send to the base station to which the relay node belongs.

4. The method according to claim 1, wherein the method further comprises the steps of:

C3. If there are multiple candidate target nodes and are all base stations, select one of the multiple candidate target nodes according to the quality information received in step A and determine it as a target node, and use The identification information identifying the target node is sent to the base station to which the relay node belongs, so as to switch the service of the user equipment to the target node.

The method according to any one of claims 1 to 4, wherein the quality information comprises reference signal received power.

The method according to claim 5, wherein the predetermined condition comprises: the reference signal received power of the optional access node at the user equipment exceeds a predetermined threshold.

The method according to claim 5, wherein the predetermined condition comprises: the reference signal received by the optional access node in the user equipment is higher than any other optional access node in the user The reference signal of the device receives power.

8. A method of switching a service of a user equipment in a base station of a wireless communication network, comprising the steps of:

Receiving, from a governed relay node, identification information for identifying the candidate target node with respect to the user equipment and quality of channel quality reflecting an access connection between the candidate target node and the user equipment Information

Ii. making a decision about the target node based on the end-to-end communication link quality of the user equipment, the candidate target node;

Iii. Notifying the relay node of the decision regarding the target node.

9. The method according to claim 8, wherein the quality information comprises a reference signal received power of the candidate target node on the user equipment.

10. The method of claim 8 wherein:

In the step i, the identification information of the plurality of candidate target nodes and the quality information are received, and the decision about the target node includes the identification information of the target node.

1 1. The method according to claim 8, wherein

In the step i, only the identification information of one candidate target node and the quality information are received;

The decision regarding the target node includes information indicating whether the candidate target node is a target node.

12. A first switching device for switching a service of a user equipment in a relay node of a wireless communication network, comprising:

a first receiving device, configured to receive, from the user equipment, identifier information for identifying an optional access node, and quality of a channel quality that reflects an access connection between the optional access node and the user equipment information; The first determining means is configured to select, from the optional access nodes, one or more nodes that satisfy a predetermined condition as the candidate target node.

A second switching device for switching a service of a user equipment in a base station of a wireless communication network, comprising:

a second receiving device, configured to receive, from a jurisdiction of a relay node, identification information about the user equipment for identifying a candidate target node, and reflecting an access connection between the candidate target node and the user equipment Quality information of the channel shield quantity;

a second determining means, configured to make a decision about the target node according to an end-to-end communication link quality of the user equipment, the candidate target node;

Notification means, configured to notify the relay node of the decision regarding the target node