KR20100066696A

KR20100066696A - Method of providing service in wireless communication system

Info

Publication number: KR20100066696A
Application number: KR1020080125113A
Authority: KR
Inventors: 석용호
Original assignee: 엘지전자 주식회사
Priority date: 2008-12-10
Filing date: 2008-12-10
Publication date: 2010-06-18
Also published as: WO2010067999A2; WO2010067999A3

Abstract

PURPOSE: A service supplying method in a wireless communications system for supplying a service of proper quality to a terminal in a femto cell is provided to improve communication service quality and to prevent unnecessary access to the terminal by determining whether the terminal accesses the femto cell. CONSTITUTION: A QoS(Quality of Service) request message is transmitted to a base station(S110). The QoS request message indicates the QoS requested about the service. A QoS response message, indicating the QoS which the base station offers, is received in response to the Qos request message(S140). The base station determines whether the service is supplied according to the service quality(S150). A service accept message or a service reject message is transmitted(S160).

Description

Method of providing service in wireless communication system

The present invention relates to wireless communication, and more particularly, to a method for providing a service of appropriate quality to a terminal.

Along with the development of communication and the spread of multimedia technology, various high-capacity transmission technologies have been applied to wireless communication systems. There is a method for allocating more frequency resources as a method for increasing radio capacity, but there are limitations in allocating more frequency resources to a plurality of users with limited frequency resources. One way to make more efficient use of limited frequency resources is to make cells smaller. Making the size of the cell smaller reduces the number of users that one base station must serve, so that the base station can allocate more frequency resources to the user. By making the cell smaller, you can provide better capacity and larger capacity for many users.

Recently, research on femto-cell technology installed in homes or offices has been actively conducted. Femtocell refers to a very small mobile communication base station used indoors, such as home or office. A femtocell is connected to an IP network, which is widely used in homes and offices, and provides a mobile communication service by accessing a core network of a mobile communication system through an IP network. The user of the mobile communication system may be provided with a service through an existing macro-cell outdoors, and may be provided with a femtocell indoors. Femtocell improves indoor coverage of mobile communication system by compensating for deterioration of existing macro-cell service in buildings, and provides high-quality services to specific users. Voice services and data services can be provided.

In an environment where a macrocell and a femtocell coexist, mobility of a terminal includes a movement from a macrocell to a femtocell, a femtocell to a macrocell, a movement between a femtocell, and a femtocell to another system. In the movement to the femtocell, the UE may determine whether to access the femtocell by identifying the possibility of access to the femtocell with a femtocell list to which it can access. A terminal receiving a communication service from a macro cell or an adjacent femtocell may be continuously connected to a femtocell to receive a high quality voice service and a data service. However, in a dense environment of femtocells, radio resources that can be used by femtocells can be reduced compared to macrocells. If there are other users who prefer to use femtocells, femtocells can't provide the quality of service that users want. In a situation where a femtocell cannot provide sufficient service, if a UE unconditionally accesses a femtocell that can be accessed, the quality of communication service may be deteriorated.

Accordingly, there is a need for a method capable of providing an appropriate quality of service to a terminal moving to a femtocell.

An object of the present invention is to provide a method for providing an appropriate quality of service to a terminal moving to a femtocell.

In a wireless communication system according to an aspect of the present invention, a method for providing a service includes transmitting a Quality of Service (QoS) request message indicating a quality of service required for a service to be provided to a base station, in response to the QoS request message. Receiving a QoS response message indicating a quality of service that the base station can provide; determining whether to receive service according to the quality of service that the base station can provide; and according to the determination, a service acceptance message or denial of service. Sending a message.

A service providing method in a wireless communication system by a base station connected to a gateway via an IP network and interworking with a core network of a wireless communication system according to another aspect of the present invention provides a service request from a terminal and a QoS request message indicating the quality of the service. QoS for indicating a quality of service that can be provided to the terminal, the step of requesting the radio resource for providing the service to the gateway, the step of receiving a radio resource from the gateway and the allocated radio resource to the terminal; Sending a response message.

The femtocell may present a quality of service to a terminal requesting access according to a radio resource situation so that the terminal may determine whether to connect to the femtocell by itself, thereby preventing unnecessary connection of the terminal and improving the quality of a communication service.

1 is a block diagram illustrating a wireless communication system. Wireless communication systems are widely deployed to provide various communication services such as voice and packet data.

Referring to FIG. 1, a general wireless communication system includes a user equipment (UE) and a base station (BS). The terminal may be fixed or mobile, and may be referred to in other terms, such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), and a wireless device. A base station generally refers to a fixed station for communicating with a terminal, and may be referred to as other terms such as Node-B, Base Transceiver System, and Access Point.

One or more cells may exist in one base station.

The base station may be divided into a femto base station 20 and a macro base station 60 according to a cell coverage or deployment scheme. The cell of the femto base station 20 has a smaller size than the cell of the macro base station 60. All or some of the cells of the femto base station 20 may overlap with the cells of the macro base station 60. The femto base station 20 may be referred to by other terms such as a femto-cell, a home node-B, and a closed subscriber group (CSG). The macro base station 60 may be referred to as a macro-cell by distinguishing it from a femtocell.

The femto base station 20 is connected to a femto gateway 30 via an IP network 40. The interface between the femto base station 20 and the femto gateway 30 through the IP network 40 is called an Iuh interface. The femto gateway 30 may perform registration, authentication, and security procedures of the femto base station 20 so that the femto base station 20 may access the core network 90 of the wireless communication system. Interworking between the femto base station 20 and the core network 90 of the wireless communication system may be achieved through UMA (Unlicensed Mobile Access) technology. UMA technology is a technology that enables handover between a wired network (IP network) and a wireless network (mobile communication). A UNC (UMA Network Controller) exists in the core network 90 of the wireless communication system, and the voice service and the data service in which the IP network and the core network 90 of the wireless communication system are interworked by the UNC.

The macro base station 60 is connected to a radio network control (RNC) 70 via an Iub interface. The RNC 70 is an entity managing at least one macro base station 60 and connects the macro base station 60 to the core network 90. The macro base station 60 is connected to the core network 90 by a dedicated line, while the femto base station 20 is connected to the core network 90 through the IP network 40.

A terminal connected to the femto base station 20 is called a femto UE 10, and a terminal connected to the macro base station 60 is called a macro UE 50. The femto terminal 10 may be a macro terminal 50 through handover to a macro base station, and the macro terminal 50 may be a femto terminal 10 through a handover to a femto base station.

Hereinafter, downlink means transmission from the base station to the terminal, and uplink means communication from the terminal to the base station. In downlink, a transmitter may be part of a base station and a receiver may be part of a terminal. In uplink, a transmitter may be part of a terminal and a receiver may be part of a base station.

There is no limitation on the multiple access scheme applied to the wireless communication system. Various multiple access techniques such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Single-Carrier FDMA (SC-FDMA), and Orthogonal Frequency Division Multiple Access (OFDMA) are available. Can be.

2 illustrates mobility of a terminal in an environment in which a macro base station and a femto base station coexist. In general, a femto base station is located within the cell coverage of the macro base station.

Referring to FIG. 2, the mobility of the UE includes (a) a movement from a macro base station to a femto base station, (b) a movement from a femto base station to an adjacent femto base station, and (c) a movement from a femto base station to a macro base station. There is also a move from a femto base station to another wireless communication system. (a) a move from a macro base station to a femto base station or (b) a move from a femto base station to an adjacent femto base station is called an inbound handover, and (c) the move from a femto base station to a macro base station is an outbound hand. This is called overbound handover.

In inbound handover, a UE may perform handover only to a femto base station included in an accessible cell list. The accessible cell list indicates a femto base station to which the terminal is allowed to access, and may be configured as a cell ID of the femto base station. The cell ID of the femto base station may consist of a tracking area identifier (Tracking Area ID), a physical cell ID (Physical cell identifier). The accessible cell list may be previously specified in the memory of the terminal. Alternatively, the accessible cell list may be provided or updated by a higher network.

On the other hand, the terminal may have a forbidden cell list (forbidden cell list). The prohibition cell list indicates a femto base station for which access of a terminal is prohibited and may be configured as a cell ID of the femto base station. The terminal restricts handover to the femto base station corresponding to the cell ID of the femto base station included in the prohibited cell list. The terminal may ignore system information transmitted from the femto base station corresponding to the cell ID of the femto base station included in the forbidden cell list.

In the following description, it is assumed that the terminal performs connection or handover to the femto base station based on the accessible cell list. However, even when the terminal performs access or handover to the femto base station based on the prohibited cell list, the proposed service providing method may be applied as it is.

The femto base station can be divided into a private femto base station (private femto BS) that can be accessed only by a specific user and a public femto BS that all users can access. Private femto base stations restrict access to users except for specific users, while public femto base stations allow all users to access through a normal authentication procedure. The terminal may access the private femto base station when the accessibility cell list has the ID of the private femto base station, but may access the public femto base station even when the accessibility cell list does not include the ID of the public femto base station.

The femto base station is connected to the core network of the mobile communication system through the IP network. The IP network may be a public network that is commonly used by ordinary users, and access through the public network may result in a decrease in the transmission rate or disconnection depending on circumstances. May not be guaranteed. Therefore, in the inbound handover, the quality of service of the IP network between the femto gateway and the femto base station should be considered. In addition, even if a femto base station provides a service only to a specific user, the amount of radio resources that can be actually used may be reduced due to interference with neighboring femto base stations, and a new user may be required while allocating a large amount of radio resources to another user. May not be able to provide quality services. In inbound handover, if the UE performs the handover to the femto base station unconditionally without considering the quality of service that the femto base station can provide, it may be provided with a low quality service.

Hereinafter, inbound handover in consideration of the quality of service that a femto base station can provide will be described.

3 shows a service providing method according to an embodiment of the present invention.

Referring to FIG. 3, the terminal transmits a Quality of Service (QoS) request message to the femto base station (S110). The terminal may have a list of accessible cells and determine whether the femto base station can be accessed by identifying the cell ID of the femto base station through system information transmitted from the femto base station. Alternatively, the terminal may maintain a prohibited cell list, and may determine whether it is a femto base station to which it cannot access based on the prohibited cell list. The terminal transmits a QoS request message to the femto base station to which it can connect. The QoS request message may be transmitted through a physical control channel. The physical control channel may be a physical uplink control channel (PUCCH). Alternatively, the QoS request message may be transmitted through an upper layer message of the physical layer. For example, the QoS request message can be sent via an RRC message or a MAC message.

The QoS request message is a message indicating the quality of a service that the terminal wants to receive from the femto base station, and the QoS request message may include application-specific QoS information used by the terminal.

Table 1 shows an example of information included in the QoS request message.

Information Content Connection information Flow ID, Traffic type, User priority Frame size Nominal frame size, Maximum frame size Service interval Minimum service interval, Maximum service interval Data rate Minimum data rate, mean data rate, peak data rate Burst size Delay bound

The QoS request message includes connection information, frame size, service interval, data rate, and burst size for the service that the terminal wants to receive from the application or femto base station in use. burst size), delay bound, and the like.

The femto base station may have secured radio resources that it can use. The femto base station confirms whether the service can be sufficiently provided by the radio resources secured for the QoS requested by the terminal. Alternatively, the femto base station may be in a state in which no radio resources are allocated to the terminal.

If the femto base station does not secure the radio resources or does not satisfy the QoS of the service requested by the terminal with the secured radio resources, the femto base station requests the radio resources to the femto gateway (S120). The femto base station requests the femto gateway for radio resources that can satisfy the QoS of the service requested by the terminal according to the QoS request message of the terminal.

The femto gateway allocates radio resources in response to the radio resource request of the femto base station (S130). The femto gateway may allocate radio resources to the femto base station according to a radio resource allocation policy determined in consideration of radio resources allocated to the femto base stations managed by the femto gateway. Since there is a limit to radio resources that can be allocated by the femto gateway, it may not be possible to allocate enough radio resources to all femto base stations. The femto gateway allocates the maximum radio resources that can satisfy the radio resources requested by the femto base station.

The femto base station transmits a QoS response message for the QoS request message of the terminal based on the radio resources secured by the femto base station (S140). The QoS response message indicates the quality of service that the femto base station can provide to the terminal. The QoS response message indicates the QoS that the femto base station can provide for the QoS of each application requested by the terminal. The QoS response message may be sent over the physical control channel. The physical control channel may be a physical downlink control channel (PDCCH). Alternatively, the QoS response message may be transmitted through an upper layer message of the physical layer. For example, the QoS response message may be sent via an RRC message or a MAC message.

The femto base station may transmit an acknowledgment message in a QoS response message if all the QoS of the service requested by the terminal can be satisfied. When the femto base station cannot satisfy all the QoS of the service requested by the terminal, the femto base station may include the rejection message and the QoS that can be provided to the terminal on the basis of the radio resources secured by the terminal. . The accept message and the reject message may be expressed in 1 bit.

The terminal determines whether to receive the service of the QoS proposed by the femto base station (S150). When receiving the acceptance message from the femto base station, the terminal determines to receive the service requested from the femto base station. When receiving a rejection message from the femto base station, the terminal examines the QoS presented by the femto base station. The terminal determines whether to receive a service from the femto base station in consideration of the possibility of handover to another neighboring femto base station, the QoS that the macro base station can provide, and whether the application can be performed with the proposed QoS.

If the terminal determines to receive the service from the femto base station, and transmits a service acceptance message, if it determines not to receive the service transmits a service rejection message (S160). Upon receiving the service acceptance message from the terminal, the femto base station allocates radio resources to the terminal and provides a service. The femto base station receiving the service rejection message from the terminal may inform the femto gateway of the release of the secured radio resource without allocating the radio resource to the terminal.

As described above, since the UE can determine whether the femto base station can support the QoS desired to be provided prior to the handover to the femto base station, the UE unnecessarily handovers to the femto base station with poor quality of service. It can prevent. The femto base station may present a QoS that can be provided to the terminal requesting access to limit the access of the terminal requiring excessive QoS to reduce the overload and improve the quality of service.

4 illustrates a service providing method according to another embodiment of the present invention.

Referring to FIG. 4, the terminal transmits a quality of service (QoS) request message to the femto base station (S210). The terminal may maintain an accessible cell list or a prohibited cell list. The terminal may determine whether the femto base station is accessible based on the accessible cell list or the prohibited cell list. The terminal transmits a QoS request message to the femto base station to which it can connect. The QoS request message may be transmitted through a physical control channel. The physical control channel may be a physical uplink control channel (PUCCH). Alternatively, the QoS request message may be transmitted through an upper layer message of the physical layer. For example, the QoS request message can be sent via an RRC message or a MAC message. The QoS request message may include application-specific QoS information used by the terminal. As shown in Table 1, the QoS request message includes connection information, frame size, service interval, and data rate for a service that the terminal wants to receive from the application or femto base station in use. , Burst size, delay bound, and the like.

If the femto base station does not secure the radio resources or does not satisfy the QoS of the service requested by the terminal with the secured radio resources, the femto base station requests the radio resources to the femto gateway (S220). The femto base station requests the femto gateway for radio resources that can satisfy the QoS of the service requested by the terminal according to the QoS request message of the terminal.

The femto gateway allocates radio resources in response to the radio resource request of the femto base station (S230). The femto gateway may allocate radio resources to the femto base station according to a radio resource allocation policy determined in consideration of radio resources allocated to the femto base stations managed by the femto gateway.

The femto base station transmits a QoS response message for the QoS request message of the terminal based on the radio resources secured by the femto base station (S240). The QoS response message may be sent over the physical control channel. The physical control channel may be a physical downlink control channel (PDCCH). Alternatively, the QoS response message may be transmitted through an upper layer message of the physical layer. For example, the QoS response message may be sent via an RRC message or a MAC message.

The QoS response message may include multi-access type information. The multiple access type refers to a connection type in which a femto base station supports some of services requested by a terminal and other services in other systems. The femto base station may not satisfy the QoS for a specific service among the services requested by the terminal. In this case, a specific service can be supported by using a radio resource of the macro base station without using a radio resource secured by the femto base station. The multiple access type information may include information about the connection to the femto base station and the connection to the macro base station. The multiple access type information may include one or more multiple access types. The multiple access type information may include a service list provided by the femto base station and a service list provided by the macro base station. The multiple access type information may include an identifier for connection to a femto base station and an identifier for connection to a macro base station.

For example, suppose that a terminal requests a voice service and a data service to a femto base station, and requests a required QoS of each service to a femto base station. The femto base station may satisfy the QoS for the data service, but may not satisfy the QoS for the voice service requiring the real time service. If the delay of the service that can be provided by the femto base station is greater than the delay threshold of the voice service, the femto base station may provide the voice service using radio resources of the macro base station. Multiple access type information about this may be included in the QoS response message and transmitted to the terminal.

The terminal determines whether to receive a service according to the multiple access type suggested by the femto base station (S250). The UE determines whether to receive the service according to the multiple access type in consideration of the possibility of handover to another neighboring femto base station, the QoS that the macro base station can provide, and the ability to perform data transmission and reception according to the proposed multiple access type. Decide

When the terminal determines to receive the service according to the multiple access type, and transmits the connection type selection message to the femto base station (S260). The access type selection message may indicate a multiple access type selected by the terminal among one or more multiple access types presented by the femto base station. The access type selection message means a request for a service according to a multiple access type presented by a femto base station. If the terminal cannot receive the service according to the multiple access type, the service rejection message may be transmitted.

Upon receiving the access type selection message from the terminal, the femto base station allocates radio resources to a service to be provided by the femto base station. The femto base station may serve as a relay base station for the services provided by the macro base station. The relay base station refers to a base station that relays data transmitted from a macro base station to a terminal as it is. The macro base station may have a wider cell area than the relay base station, and the relay base station relays the data transmitted from the macro base station to the terminal as it is. For example, the femto base station may provide a data service by interworking with a core network of a mobile communication system through an IP network and may relay a voice service transmitted from the macro base station to the terminal.

All the above functions may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), or the like according to software or program code coded to perform the function. The design, development and implementation of the code will be apparent to those skilled in the art based on the description of the present invention.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made therein without departing from the spirit and scope of the invention. You will understand. Therefore, the present invention is not limited to the above-described embodiment, and the present invention will include all embodiments within the scope of the following claims.

1 is a block diagram illustrating a wireless communication system.

2 illustrates mobility of a terminal in an environment in which a macro base station and a femto base station coexist.

Claims

Transmitting a Quality of Service (QoS) request message indicating a quality of service required for a service to be provided to a base station;

Receiving a QoS response message indicating a quality of service that the base station can provide in response to the QoS request message;

Determining whether to receive a service according to a quality of service that the base station can provide; And

And transmitting a service acceptance message or a service rejection message according to the determination.

The method of claim 1, wherein the base station interworks with a core network of a wireless communication system through an IP network.

The method of claim 1, wherein the base station relays the data transmitted from the macro base station having a wider cell area to the terminal as it is.

The wireless communication system of claim 1, wherein the base station interworks with a core network of a wireless communication system through an IP network and relays data transmitted from a macro base station having a wider cell area than the base station to a terminal as it is. How to Provide.

The method of claim 1, wherein the QoS request message is transmitted to a base station included in an accessible cell list.

The method of claim 1, wherein the QoS request message and the QoS response message are transmitted through an RRC message or a MAC message.

The wireless communication system of claim 1, wherein the QoS response message includes multiple access type information indicating a connection type supported by the base station for some of the services to be provided and other systems for the remaining services. How to provide services on your system.

8. The method of claim 7, wherein the multiple access type information includes at least one multiple access type, and the service acceptance message indicates any one of multiple access types.

A service providing method in a wireless communication system by a base station connected to a gateway through an IP network and interworking with a core network of a wireless communication system,

Receiving a QoS request message indicating a provision of a service and a quality of the service from a terminal;

Requesting the gateway for radio resources for providing the service;

Receiving radio resources from the gateway; And

And transmitting a QoS response message indicating a quality of service that can be provided to the terminal to the allocated radio resource.

The method of claim 9, further comprising receiving an accept message or a reject message for the QoS response message from the terminal.

10. The method of claim 9, wherein the radio resources are allocated to some of the services requested by the terminal and the radio resources of the neighboring base station are used for the remaining services.