KR20100034480A - Method for access processing of user equipment in femto cell and femto access point therefor - Google Patents

Abstract

PURPOSE: A method for access processing of user equipment in a femto cell and a femto access point thereof are provided to supply low cost communication such as a femtocell to a subscriber. CONSTITUTION: A femto base station receives a connection request from a mobile terminal(S301). If an acceptable capacity of the mobile terminal is exceed, the femto base station confirms the registration of the user of the mobile terminal(S303,S305). If the mobile terminal of a user is connected to the femto base station, the femto base station process a forced handover of a neighbor macro cell around the mobile of the user terminal(S307,S311). The femto base station permits the connection of the mobile terminal requesting connection(S313).

Description

METHOD FOR ACCESS PROCESSING OF USER EQUIPMENT IN FEMTO CELL AND FEMTO ACCESS POINT THEREFOR}

The present invention relates to a femto cell technology, and more particularly, to a method for processing a connection of a mobile terminal in a femto base station of a femto cell, and a femto base station therefor.

Femto Cell (Femto Cell) is a technology that provides a mobile communication service to a region much smaller than the existing mobile communication radius through a femto base station (Femto AP). Femtocells are also used to guarantee the quality of mobile communication services in areas where shadows of the macro cell are degraded, such as homes and buildings, or in shadowed areas. Can also be used as a means of providing. In addition, since femtocells use a universal Internet line for connection to the core network, the installation cost and maintenance cost are low, and the location where the Internet line is installed can be installed anywhere. have.

In general, femto base stations in a femto cell support a small number of concurrent users (typically four) because of their small coverage. Therefore, when some users approach the femto base station of the femto cell and try to call simultaneously, a lot of capacity is exceeded.

Accordingly, when the terminal registered to the femto base station of the femto cell requests access to the femto base station, if the capacity that the femto base station can support at the same time is exceeded, the number of users is no longer accommodated, thus disconnecting the user requesting a new connection. Let's go.

One of the main uses of femtocells is to provide a fee benefit for subscribers who have subscribed to femtocell services.Femtocell femto base stations have a list of users who can access the femtocell preferentially. We need to let users connect first. However, as described above, when several users simultaneously access the femto base station of the femto cell and exceed the call capacity, the subscribers who are subscribed to the femto cell service are forcibly disconnected when attempting to access the femto cell. There is a problem that can not be provided femtocell service.

The present invention has been proposed to solve the above problems, and when the mobile terminal of the registered subscriber accesses to the femto base station of the femto cell more than the capacity (that is, the number of users) that the femto base station can accommodate, the corresponding mobile terminal It is an object of the present invention to provide a method for processing access of a mobile terminal in a femto cell that accepts and accepts a connection of a mobile station and a femto base station therefor.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

In accordance with a first aspect of the present invention for achieving the above object, a method for access processing of a registered subscriber's mobile terminal in a femto base station of a femto cell comprises: receiving an access request from the mobile terminal; Determining whether the mobile terminal is accessible by checking a connection capacity; Handover processing a mobile terminal of an unregistered user among mobile terminals currently connected to a macro cell when the access capacity is exceeded; And completing the access process of the access requesting mobile terminal.

In addition, a femto base station of a femtocell connected to a core network of a communication system and an IP network for providing a communication service to a mobile terminal according to the second aspect of the present invention for achieving the above object is a mobile terminal entering the femto cell A connection processing unit that performs connection processing based on a connection accommodation capacity upon a connection request of the network; A registered subscriber management unit for confirming whether a user of the mobile terminal is a registered subscriber based on a command according to a connection capacity check of the connection processing unit; And a handover processor configured to handover the unregistered user's mobile terminal to a macro cell based on a result of the confirmation of the registered subscriber management unit.

The present invention as described above, it is possible to ensure the provision of inexpensive communication services, such as femto zone to subscribers to the femto cell service. In addition, the general user who is not a registered subscriber can reduce the load of the macro cell by accepting the connection to the femto base station in a situation where the capacity of the femto base station is not exceeded without inducing a connection to the macro cell unconditionally.

The foregoing and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, in which: There will be. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram schematically illustrating a network configuration of a mobile communication system including a femto cell to which the present invention is applied.

Referring to FIG. 1, a mobile communication system includes a femto cell 110, a macro cell 130, and a core network 150.

The macro cell 130 is a conventional radio access cell of a mobile communication system and includes a base station (Node-B) for managing radio resources and a base station controller (RNC) for controlling the base station. To provide a mobile communication service.

The femto cell 110 is mainly for the purpose of guaranteeing the quality of mobile communication service in the area or shadow area where the radio wave of the macro cell 130 is degraded, such as a home or a building, or provides a low rate such as a femto zone service. As a radio access cell utilized for the purpose of doing so, a femto base station 113 (Femto AP) connected with a universal Internet line (IP network) is used. The mobile terminal 110-1 entering the femto cell 110 is connected to the femto base station 113 and is connected to the core network 150 through the femto base station 113 through a universal Internet line. In general, the femto cell 110 supports one frequency, uses a different frequency from the macro cell 130 to reduce interference with the macro cell 130, and the femto base station 113 of the femto cell 110 is Because of its small coverage, it supports a small number of concurrent users (typically four).

The femto base station 113 of the femto cell 110 may be referred to as a femto base station 113, a pico base station, a ubico base station, a femto access point (AP), etc. according to a policy of a manufacturer or a telecommunications company. The femto cell 110 may also be referred to as a pico cell, ubicell, or the like. The femto cell in the present invention is to be understood as being applicable to any connection to the core network 150 of the communication system to provide a communication service to the mobile terminal through a universal Internet circuit.

The femto base station 113 of the femto cell 110 stores a neighbor list, which is information of the neighboring macro cells 130, and stores and manages information of subscribers subscribed to the femto cell service. The femto base station 113 of the femto cell 110 when the subscriber is subscribed to the femto cell service when a normal user is connected and receiving service attempts a new call, when the call capacity is exceeded by checking the call capacity The user is forcibly handed over to the macro cell 130, and the subscriber who subscribes to the femto cell service is accommodated.

The core network 150 is a network of a mobile communication system for providing a data service and a voice service. The core network 150 is connected to the macro cell 130 through an exchanger (MSC) or a packet switched node (SGSN), and the femtocell ( 110 is connected through an IP network and a gateway GW to provide a communication service to the mobile terminal 110-1 in the macro cell 130 or the femto cell 110.

2 is a diagram illustrating a configuration of a femto base station according to an embodiment of the present invention.

As shown in FIG. 2, the femto base station 113 according to the present embodiment includes a terminal access processing unit 210, a registered subscriber management unit 230, a handover processing unit 250, and a registered subscriber information storage unit 270. do.

The terminal access processor 210 performs the functions of the base station NodeB and the base station controller RNC of the macro cell 130 to communicate with the mobile terminal 110-1 entering the femto cell 110 to allocate radio resources. And connect the mobile terminal 110-1 to the core network 150 of the mobile communication system. The terminal access processor 210 accesses the core network 150 through the IP network.

In addition, the terminal access processing unit 210 checks the access capacity of the femto base station when the access request of the mobile terminal 110-1 exceeds the capacity of the access terminal until the capacity of the access capacity is removed. The connection processing of 110-1) is reserved, and when the excess of the connection accommodation capacity is eliminated, the connection processing of the mobile terminal 110-1 is completed.

The registered subscriber manager 230 checks whether the mobile terminal 110-1 to communicate with the terminal access processor 210 is first connected according to the instruction of the terminal access processor 210. .

Specifically, the registered subscriber management unit 230 receives the information of the mobile terminal 110-1 from the terminal connection processing unit 210 when the femto base station 113 can no longer accommodate the mobile terminal, and the information. And the registered subscriber information stored in the registered subscriber information storage unit 270, and confirms whether the user of the mobile terminal 110-1 is a registered subscriber. When the user of the mobile terminal 110-1 is a registered subscriber, the registered subscriber management unit 230 requests the handover processing unit 250 for handover processing to the macro cell 130 for the mobile terminal of the unregistered user.

The handover processing unit 250 selects a mobile terminal of a non-registered general user from the femto base station 113 among mobile terminals currently connected according to a request of the registered subscriber management unit 230 to force the macro cell 130. Handover process. In detail, the handover processor 250 requests a signal strength of a neighboring macro cell to a mobile terminal of a general user to be handed over, and accordingly, a macro having the largest signal strength using the received signal strength of the neighboring macro cell. Force handover to cell 130. When the mobile terminals of a plurality of general users are connected, the most recently connected mobile terminal may be selected as the handover target, or the first connected mobile terminal may be selected as the handover target. Criteria for selection can be determined in a variety of ways.

3 is a flowchart illustrating a method for processing access of a mobile terminal in a femto base station according to an embodiment of the present invention.

Referring to FIG. 3, the femto base station 113 receives an access request from the mobile terminal 110-1 entering the femto cell area (S301). Upon receiving the access request, the femto base station 113 checks whether the number of currently connected users is the maximum acceptable number of users and confirms whether the access request mobile terminal 110-1 can be accommodated (S303).

If the capacity does not exceed the allowable capacity, that is, if there is a sufficient number of accessible users, the femto base station 113 allows the access request of the mobile terminal 110-1 to request the connection (S313).

On the contrary, if the capacity exceeded the allowable capacity, i.e., the number of accessible users is not sufficient, the femto base station 113 registers with the femto base station 113 the user of the mobile terminal 110-1 which requested the access as a next process. Check whether the subscriber is a (S305). The femto base station 113 compares the identification number of the mobile terminal 110-1 that requested the connection with the information of the registered subscriber, and confirms whether the user of the mobile terminal 110-1 that requested the connection is a registered subscriber. .

If the user of the mobile terminal 110-1 requesting access is not a registered subscriber, the femto base station 113 rejects the access of the mobile terminal 110-1 requesting access and induces access to the macro cell 130 ( S309). On the contrary, when the user of the mobile terminal 110-1 requesting access is a registered subscriber, the femto base station 113 checks whether there is a mobile terminal of a general user who is not a registered subscriber among mobile terminals currently connected (S307). .

When the mobile terminal of the general user is not connected, the femto base station 113 rejects the connection of the mobile terminal 110-1 that requested the connection and induces connection to the macro cell 130 (S309). On the contrary, when the mobile terminal of the general user is connected, the femto base station 113 forcibly handovers the mobile terminal of the general user to the neighboring macro cell 130 (S311), and the mobile terminal 110- that requested the connection. 1) allow connection (S313). The femto base station 113 requests the mobile terminal of the general user to measure the signal strength of the neighboring macro cell, thereby forcing the hand to the macro cell 130 having the largest signal strength by using the received signal strength of the neighboring macro cell. Over processing

4 is a flowchart illustrating a process of access processing of a mobile terminal in a femto cell according to an embodiment of the present invention.

Referring to FIG. 4, the femto base station 113 of the femto cell 110 is connected to a mobile terminal MS of a general user instead of a registered subscriber (S401). At this time, the mobile station (MS) 110-1 of the registered subscriber enters the femto cell 110 region, and the mobile terminal 110-1 connects to the femto base station 113 with RRC (Radio Resource Control). Set up (S403). More specifically, the mobile terminal 110-1 transmits an RRC connection request message to the femto base station 113, and the femto base station 113 sends an RRC connection setup message to the mobile terminal 110-1 in response thereto. send. The mobile terminal 110-1 transmits an RRC Connection Setup Complete message to the femto base station 113. As such, when the RRC connection setup is completed, the mobile terminal 110-1 transmits a service request message to the femto base station 113 (S405).

Meanwhile, the femto base station 113 performs the operation as described with reference to FIG. 3 in the above-described RRC connection setup process. That is, the femto base station 113 can accommodate the mobile terminal 110-1 as a new call flows from the mobile terminal 110-1, and if the capacity is exceeded to accommodate the mobile terminal 110-1. If not, it is checked whether the user of the mobile terminal 110-1 is a subscriber registered in the femto base station 113. Among the mobile terminals that are currently connected as follows because the capacity of the number of acceptable users has been exceeded and the mobile terminal 110-1 cannot be accommodated and the user of the mobile terminal 110-1 is a registered subscriber. The mobile terminal of the general user is forcibly handed over to the macro cell 130.

To this end, the femto base station 113 requests the mobile terminal of the general user to measure the signal strength of the neighboring macro cell and accordingly selects the macro cell 130 having the largest signal strength using the received signal strength of the neighboring macro cell. do. Subsequently, the femto base station 113 sends a relocation request message including identification information of the mobile terminal of the general user and information of the selected macro cell 130 through the IP network to the core network 150 (MSC or SGSN). (S407).

Upon receiving the handover request message, the core network 150 transmits a relocation request message to the base station controller RNC of the macro cell 130 corresponding to the macro cell information included in the handover request message. In operation S411, the base station controller RNC transmits a radio link setup request message to the base station NodeB in operation S411. Upon receiving the radio link setup request message, the base station NodeB prepares to set up a wireless link with a mobile terminal of a general user, and transmits a radio link setup response message to the base station controller RNC (S413). ).

The base station controller (RNC) having received the radio link setup response message transmits a relocation request ACK message to the core network 150 (S415). Accordingly, the core network 150 transmits the femto base station through the IP network. In step S417, a handover command message is transmitted.

Upon receiving the handover command message, the femto base station 113 transmits a physical channel reconfiguration message to the mobile terminal of the general user (S419). The physical channel reconfiguration message includes channel information allocated by the base station NodeB of the macro cell 130, frequency information of the base station NodeB, and the like. The mobile terminal of the general user accesses the base station NodeB of the macro cell 130 using the above information (S421).

As the mobile terminal of the end user is connected, the base station NodeB of the macro cell 130 transmits a message (RL Restore Indication) indicating radio link recovery to the base station controller (RNC) (S423), and the base station controller (RNC). The core network 150 transmits a message (Relocation Detect) indicating the handover fact (S425).

Meanwhile, the mobile terminal of a general user who has completed access to the base station NodeB of the macro cell 130 completes the physical channel reconfiguration to the base station controller RNC via the base station NodeB of the macro cell 130 (Physical Channel Reconfiguration Complete). Message) (S427), and thus, the base station controller (RNC) transmits a handover complete message to the core network 150 to complete the handover procedure (S429). The core network 150 releases the Iu interface with the femto base station 113.

After the handover process is forcibly handed over from the femto cell 110 to the macro cell 130 according to the excess number of users allowed to access the femto base station 113, the femto base station 113 receives the mobile terminal 110- of the registered subscriber. According to the service request of 1), a service request message is transmitted to the core network 150 and a service response message is received (S431, S433). The femto base station 113 transmits a service response message to the mobile terminal 110-1 of the registered subscriber to complete a final access process (S435).

Therefore, it is possible to guarantee the provision of inexpensive communication services such as femto zones to subscribers who have subscribed to femto cell services. In addition, the general user who is not a registered subscriber unconditionally induces access to the macro cell 130 and accepts the access to the femto base station 113 in a situation where the capacity of the femto base station 113 is not exceeded. ) Can be reduced.

5 is a flowchart illustrating a process of access processing of a mobile terminal in a femto cell according to another embodiment of the present invention.

In FIG. 5, the same reference numerals as used in FIG. 4 are the same and the description thereof will be omitted. In the embodiment described with reference to FIG. 4, after a service request message is received from the mobile terminal 110-1 of the registered subscriber to the femto base station 113 (S405), a service response is a response thereto. ) There is a relatively long time difference between the time (S435) when the message is transmitted to the mobile terminal (110-1) of the registered subscriber. Since the time point at which the service response message is transmitted to the mobile terminal 110-1 of the registered subscriber is after handover processing of the mobile terminal of the general subscriber to the macro cell 130 is completed, the mobile terminal of the registered subscriber ( Service delay for 110-1) may occur.

Accordingly, as shown in FIG. 5, the femto base station 113 simultaneously transmits a relocation request message and a service request message to the core network 150 (S407 and S501). A service response message is received in advance from 150 (S503). The femto base station 113 transmits a physical channel reconfiguration message to the mobile terminal of the general user (S419) and immediately transmits a service response message to the mobile terminal 110-1 of the registered subscriber. After the authentication encryption process is completed (S505). Accordingly, the mobile station 110-1 of the registered subscriber receives a service response message with a minimum time delay after transmitting a service request message to the femto base station 113.

While this specification contains many features, such features should not be construed as limiting the scope of the invention or the claims. Also, the features described in the individual embodiments herein can be implemented in combination in a single embodiment. Conversely, various features described in a single embodiment herein can be implemented individually in various embodiments or in combination as appropriate.

Although the operations are described in a particular order in the drawings, they should not be understood as being performed in a particular order as shown, or in a sequence of successive orders, or all described actions being performed to obtain a desired result. . In certain circumstances, multitasking and parallel processing may be advantageous. In addition, it should be understood that the division of various system components in the above-described embodiments does not require such division in all embodiments. The program components and systems described above may generally be packaged in a single software product or multiple software products.

The method of the present invention as described above may be implemented as a program and stored in a recording medium (CD-ROM, RAM, ROM, floppy disk, hard disk, magneto-optical disk, etc.) in a computer-readable form. Since this process can be easily implemented by those skilled in the art will not be described in more detail.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

1 is a diagram schematically illustrating a network configuration of a mobile communication system including a femto cell to which the present invention is applied.

2 is a diagram illustrating a configuration of a femto base station according to an embodiment of the present invention.

3 is a flowchart illustrating a method for processing access of a mobile terminal in a femto base station according to an embodiment of the present invention.

4 is a flowchart illustrating a process of access processing of a mobile terminal in a femto cell according to an embodiment of the present invention.

5 is a flowchart illustrating a process of access processing of a mobile terminal in a femto cell according to another embodiment of the present invention.

Claims (9)

A method of accessing a mobile terminal of a registered subscriber in a femto base station of a femto cell, (a) receiving an access request from the mobile terminal; (b) determining whether a connection of the mobile terminal is possible by checking a connection capacity; And (c) handover processing an unregistered user's mobile terminal to a macro cell among mobile terminals currently connected when the access capacity is exceeded; (d) completing the access processing of the access requesting mobile terminal; and a mobile terminal access processing method at a femto base station. The method of claim 1, The completion of the connection process of step (d), The mobile terminal access processing method of the femto base station, characterized in that is performed after the handover process for the mobile terminal of the unregistered user is completed. The method of claim 1, The completion of the connection process of step (d), The mobile terminal in the femto base station is performed immediately after transmitting a channel reconfiguration message including the information of the macro cell to the mobile terminal of the unregistered user during the process of handover to the mobile terminal of the unregistered user. How to handle a connection. The method according to claim 2 or 3, In step (c), Requesting the mobile terminal of the unregistered user to measure the signal strength of a neighboring macro cell; Receiving signal strength information of neighboring macro cells from the mobile terminal of the unregistered user; Selecting a macro cell having the largest signal strength as a target of handover; And And transmitting a handover request message including information on the selected macro cell to the core network. A femto base station apparatus of a femto cell connected to a core network of an communication system through an IP network and providing a communication service to a mobile terminal, A connection processor configured to perform connection processing based on a connection capacity when a mobile terminal enters a femto cell; A registered subscriber management unit for confirming whether a user of the mobile terminal is a registered subscriber based on a command according to a connection capacity check of the connection processing unit; And And a handover processor configured to handover a mobile terminal of an unregistered user among the mobile terminals currently being accessed to a macro cell based on a result of the confirmation of the registered subscriber management unit. The method of claim 5, The connection processing unit, The femto base station apparatus, characterized in that to complete the connection processing of the mobile terminal requesting the connection after receiving the message according to the handover completion to the handover processing unit. The method of claim 5, The connection processing unit, The femto base station apparatus, characterized in that the connection processing of the mobile terminal requesting the connection is completed immediately after the channel reconfiguration message is transmitted to the mobile terminal of the unregistered user by the handover processing unit. 8. The method according to claim 6 or 7, The handover processing unit, And comparing the signal strengths of the neighboring macrocells received from the mobile terminal of the unregistered user to determine the macrocell to be handed over. 8. The method according to claim 6 or 7, The connection processing unit, The femto base station apparatus, characterized in that when the user of the mobile terminal requesting access is not a registered subscriber, the access is denied.

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