KR101032475B1 - Mobile communication system and paging method using femtocell - Google Patents

Abstract

The present invention relates to a mobile communication system and a paging method using a femtocell. According to an aspect of the present invention, a mobile communication system for operating a femtocell is disclosed. In the mobile communication system according to an embodiment of the present invention, a paging controller for transmitting a paging signal to a macro base station corresponding to a paging group number recently registered by a mobile terminal, and registering the femto base station searched by the mobile terminal in a relay target list, And a macro base station for relaying the paging signal to a femto base station registered in the relay target list, and a femto base station for broadcasting the paging signal relayed from the macro base station to the mobile terminal through a paging channel.

Femtocell, macrocell, paging

Description

Mobile communication system and paging method using femtocell {MOBILE COMMUNICATION SYSTEM AND PAGING METHOD USING FEMTOCELL}

The present invention relates to a mobile communication system and a paging method using a femtocell, and more particularly, to a mobile communication system and a paging method capable of efficiently paging in a mobile communication system operating a femtocell.

Femto cell (Femto cell) is a small base station that provides a mobile communication service to an area of about 30m radius, also known as Home Node-B (Home Node-B). Femtocells are mainly installed in areas or shadowed areas where radio waves of macro cells are degraded, such as inside homes or buildings, and are installed for the purpose of compensating the quality of mobile communication services. In particular, the femtocell has an advantage of excellent mobility because it can be installed in any area where the Internet line is installed and the maintenance cost is low by using a general-purpose Internet line for communication with the core network.

Since the mobile terminal can change its location from time to time, the location must be registered with the paging controller. When the mobile communication system transmits data to a specific terminal, the mobile communication system may transmit a paging signal through the corresponding base station by using the location information registered by the mobile terminal. The location information may be a paging group number, and the mobile station receives the paging group number from the base station upon receiving the paging signal. If the received paging group number and the last updated paging group number are different from each other, the mobile station performs a location update to the current location by the paging controller through the current base station.

As the size of the paging group grows, there is less need to perform location update, thereby reducing the location update load. However, as the paging group size increases, the number of base stations that need to transmit a paging signal increases, which increases the paging load. Therefore, properly managing the paging group size is a very important performance decision in the mobile communication system.

If the paging group management of the existing mobile communication system is applied as it is in the mobile communication system using the femtocell, there is a problem that the paging load or location update load may be excessively increased.

That is, when the paging group is set to be larger than the size of the macrocell, the paging controller must transmit a paging signal to the femto base station of the numerous femtocells present in the macrocell. This means an increase in the number of base stations that the paging controller must manage, and there is a problem in that paging load increases.

In addition, when the paging group is set in femtocell units, a mobile terminal may frequently move between femtocells. Since the mobile station performs a location update every time it moves between femtocells, the paging controller has a problem that an overload may occur due to the location update.

An object of the present invention is to minimize paging load and location update load in a mobile communication system operating a femtocell.

In addition, an object of the present invention is to efficiently page a mobile communication system using a femtocell.

According to an aspect of the present invention, a mobile communication system for operating a femtocell is disclosed.

In the mobile communication system according to an embodiment of the present invention, a paging controller for transmitting a paging signal to a macro base station corresponding to a paging group number recently registered by a mobile terminal, and registering the femto base station searched by the mobile terminal in a relay target list, And a macro base station for relaying the paging signal to a femto base station registered in the relay target list, and a femto base station for broadcasting the paging signal relayed from the macro base station to the mobile terminal through a paging channel.

Here, when the mobile terminal searches for a neighbor base station, when the paging signal is not received from the macro base station and the femto base station is found, the mobile station requests to register the femto base station as the macro base station.

Here, the macro base station broadcasts the paging signal to the mobile terminal through a paging channel.

Here, when the mobile terminal leaves the femtocell for a preset time or more, the femto base station requests the deregistration of the femto base station stored in the relay target list to the macro base station.

The macro base station transmits the paging group number when the paging signal is transmitted to the mobile station, and the mobile station transmits the paging group number and the registered paging group number when the paging group number is different from the macro base station. The location update is performed to the paging controller through.

According to another aspect of the present invention, a paging method performed by a macro base station in a mobile communication system operating a femtocell is disclosed.

According to an embodiment of the present invention, a paging method includes registering a femto base station receiving a registration request from a mobile terminal in a relay target list in which a list of femto base stations managed by the macro base station is stored, and controlling a paging function of the mobile terminal. Receiving a paging signal from a paging controller, relaying a paging signal to the femto base station using the relay target list, and broadcasting the paging signal through a paging channel.

In the registering of the femto base station, when the mobile station searches for a neighboring base station and as a result of the search of the mobile station, a paging signal is not received and the femto base station is found, the mobile station searches for the femto base station. And requesting registration with the macro base station.

Here, in the broadcasting of the paging signal through a paging channel, the macro base station and the femto base station broadcast the paging signal through the paging channel.

The femto base station may further include requesting deregistration to the macro base station from the femto base station stored in the relay target list when the mobile terminal leaves the femtocell for a preset time.

Here, the macro base station transmits a paging group number when the paging signal is transmitted to the mobile station. When the paging group number received from the macro base station is different from the registered paging group number, the macro base station determines the macro base station. Location updates to the paging controller.

The present invention has the effect of minimizing the paging load and location update load in the mobile communication system operating femtocell.

In addition, the present invention has the effect that the mobile communication system can efficiently page using the femtocell.

In addition, the present invention has the effect of reducing the power consumption of the mobile terminal through efficient paging.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram showing a mobile communication system using a femtocell according to an embodiment of the present invention.

Referring to FIG. 1, a mobile communication system includes a mobile terminal 10, a femto base station 20 that operates a femtocell 200, a macro base station 30 that operates a macro cell 300, an internet network 40, and a base station. A controller 50, a paging controller 60, and a core network 70 are included. It is apparent to those skilled in the art that the mobile communication system according to the present invention applies a femto base station in an existing mobile communication system, and a new component may be added or an existing component may be used to operate the femto base station.

The femtocell 200 must satisfy the following characteristics according to the current IEEE 802.16m system requirements description (System Requirement Description).

-The terminal exists within 10m to 30m.

-Seamless handover between macro cell and femtocell and between femtocell and femtocell should be supported.

-Synchronization between macrocell and femtocell, femtocell and femtocell should be possible without complexity.

-Interference detection and interference migration between macrocell and femtocell, femtocell and femtocell should be possible.

-Must coexist with WiFi and Bluetooth.

-Session connection should be maintained during handover between femtocell and WiFi.

The location information of the femto base station should be identified.

-Even if the femtocell is installed densely, it should be feasible.

The mobile terminal 10 is wirelessly connected to the femto base station 20 or the macro base station 30 to provide a call function capable of performing a typical voice call or a video call by wireless communication with another mobile terminal or a landline telephone.

The mobile terminal 10 performs paging to minimize standby power loss. The mobile terminal 10 normally wakes up periodically in the idle mode and checks whether there is data corresponding to itself through the paging channel. If there is no data, the mobile terminal 10 returns to the idle state again and does not consume power until the next cycle. The case where the mobile terminal 10 wakes up periodically is called a monitoring interval.

The mobile terminal 10 wakes up in the monitoring section and searches for neighboring base stations. At this time, the mobile terminal 10 may be in a state capable of confirming the presence of the femto base station 20 without receiving the paging signal from the macro base station 30 as a result of the search. This means that the mobile terminal 10 is located in the femtocell 200 which is an area of the femto base station 20, and the femto base station 20 does not receive and transmit a paging signal from the macro base station 30 at present. In this case, the mobile terminal 10 makes a registration request for the macro base station 30 to register the searched femto base station 20 as a relay target base station. In this case, the mobile terminal 10 may request a registration through the femto base station 20, and the macro base station 30 may register the femto base station 20 corresponding to the mobile terminal 10 as a relay target base station. Thereafter, when the paging signal is generated, the mobile terminal 10 may receive a paging signal from the macro base station 30 through the femto base station 20.

The femto base station 20 broadcasts a paging signal to the mobile terminal 10 in the femtocell 200. The femto base station 20 may receive a paging signal from the macro base station 30 and broadcast the paging channel to the mobile terminal 10.

The femto base station 20 may manage the mobile terminal 10 in the femtocell 200. When the mobile terminal 10 leaves the femtocell 200 for a predetermined time or more, the femto base station 20 requests the deregistration of the femto base station 20 registered as the relay target base station to the macro base station 30.

The femto base station 20 may be connected to the core network 70 through the Internet network 40. In general, the femto base station 20 can transmit and receive data with the core network 70 using the general-purpose Internet network 40, the femto base station 20 according to the present invention is a paging signal from the core network 70 The paging method for receiving is not applied.

The macro base station 30 is a general base station Node-B, which is connected to the mobile terminal 10 in a wireless section to control the mobile terminal 10 and connect a call channel. The macro base station 30 may receive an outgoing call from the mobile terminal 10 and transmit the outgoing call to a radio network controller (RNC) 50.

When the macro base station 30 receives a paging signal corresponding to the mobile terminal 10 in the macro cell 300 from the paging controller 60, the macro base station 30 relays the paging signal to the corresponding femto base station 20 using the relay target list. do. The relay target list includes list information on the femto base station 20 that has been requested to register from the mobile terminal 10. The macro base station 30 may update the relay target list at the request of the mobile terminal 10 or the femto base station 20.

That is, the mobile terminal 10 may search for neighbor base stations and register the found femto base station 20 with the macro base station 20. The femto base station 20, if the mobile terminal 10 is not present in the femtocell 200 for more than a predetermined time out of the femtocell 200, the macro base station to deregistration request to exclude itself from the relay target list 30 can be done.

In addition, the macro base station 30 not only relays the paging signal received from the paging controller 60 to the femto base station 20, but also broadcasts the paging signal to the mobile terminal 10 in the macro cell 300 through the paging channel. do.

The base station controller 50 controls the macro base station 30, and assigns and releases radio channels to the mobile station 10, controls the transmission output of the mobile station 10 and the macro base station 30, soft handoff and hard-cell between cells. Handoff determination, transcoding and vocoding, operation maintenance and maintenance functions for the macro base station 30 are performed.

The paging controller 60 transmits a paging signal to the macro base station 30 of the corresponding mobile terminal 10 using the location information registered by the mobile terminal 10. The paging controller 60 may transmit a paging signal and a paging group number to the mobile terminal 10 through the macro base station 30. The mobile terminal 10 may determine the location update using the paging group number to update the location.

The core network 70 includes a mobile switching center (MSC), a packet switching support node (SGSN), etc., and is composed of devices that are the core of a mobile communication system for a mobile communication service. do.

2 is a flowchart illustrating a paging method according to an embodiment of the present invention. 2 is a flowchart illustrating a method of registering the femto base station 20 as a relay target base station.

Referring to FIG. 2, the mobile terminal 10 searches for neighboring base stations (S210). The mobile terminal 10 performs the base station search in the monitoring section that periodically wakes up. The mobile terminal 10 may determine the existence of data corresponding to itself through the paging channel and perform the base station search.

Next, the mobile terminal 10 determines whether the paging signal is detected (S220).

Upon detecting the paging signal, the mobile terminal 10 performs step S250.

If the paging signal is not detected, the mobile terminal 10 detects the presence or absence of the femto base station 20 (S230).

If the femto base station 20 is not detected, the mobile terminal 10 terminates the connection with the base station.

If the femto base station 20 is detected, the mobile terminal 10 registers the searched femto base station 20 to the relay target list of the macro base station 30 (S240). The mobile terminal 10 makes a registration request to the macro base station 30 to register the searched femto base station 20 as a relay target base station. In this case, the mobile terminal 10 may make a registration request through the searched femto base station 20. The macro base station 30 may store and manage a relay target list in a data storage provided in the apparatus.

Next, when the paging signal is generated, the mobile terminal 10, the femto base station 20, and the macro base station 30 perform a paging operation (S250). That is, after the femto base station 20 is registered in the relay target list, the femto base station 20 may receive a paging signal from the macro base station 30 from the next paging signal and transmit the paging signal to the corresponding mobile terminal 10. The paging method after the macro base station 30 registers the femto base station 20 in the relay target list will be described later in detail with reference to FIG. 3.

3 is a flowchart illustrating a paging method according to an embodiment of the present invention. In more detail, FIG. 3 is a flowchart illustrating a paging method after the femto base station 20 is registered as a relay target base station.

Referring to FIG. 3, the macro base station 30 receives a paging signal (S310). The paging signal may be generated by the paging controller 60. When a user wants to transmit data to a specific mobile terminal 10, the paging controller 60 transmits a paging signal to the macro base station 30 corresponding to the paging group number last registered by the mobile terminal 10. do.

Next, the macro base station 30 checks the femto base station 20 registered in the relay target list (S320). The relay target list may include information about the mobile terminal 10 corresponding to the registered femto base station 20. The mobile terminal 10 information may be an identifier that can be identified by the macro base station 30, subscriber information, and the like.

Next, the macro base station 30 relays the paging signal to the registered femto base station 20 (S330). The macro base station 30 relays the paging signal to the femto base station 20 requiring the paging signal using the relay target list. The macro base station 30 may relay the paging signal to the femto base station 20 managing the mobile terminal 10 by checking the mobile terminal 10 information included in the relay target list.

Next, the femto base station 20 that receives the paging signal broadcasts the paging signal to the femtocell 200 through its paging channel (S340). At this time, the macro base station 30 broadcasts the paging signal to the macro cell 3000 through its paging channel. As such, the macro base station 30 broadcasts the paging signal together with the femto base station 20. This is because the mobile terminal 10 may exist in an area without the femtocell 200 in the macro cell 300.

4 is a flowchart illustrating a paging method according to an embodiment of the present invention. In more detail, FIG. 4 is a flowchart illustrating a deregistration method of the femto base station 20.

Referring to FIG. 4, the femto base station 20 broadcasts a paging signal to the mobile terminal 10 (S410). According to the paging method described above with reference to FIGS. 3 and 4, the femto base station 20 broadcasts a paging signal to the mobile terminal 10.

Next, the femto base station 20 determines whether the mobile terminal 10 exists in the femtocell 200, and if the mobile terminal 10 does not exist, whether the mobile terminal 10 does not exist for a predetermined time or more. It is determined (S420).

As a result, when the mobile terminal 10 does not exist in the femtocell 200 for a predetermined time or more, the femto base station 20 requests the deregistration of the femto base station 20 to the macro base station 30 (S430). The macro base station 30 receiving the deregistration request may delete the corresponding femto base station 20 from the stored relay target list.

As such, the macro base station 30 manages the relay target list for the femto base station 20, so that the paging controller 60 transmits a paging signal to the macro base station 30, the macro base station 30 is the femto Only the base station 20 can transmit the paging signal.

The paging method according to an embodiment of the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded in a computer readable medium. Computer-readable media may include, alone or in combination with the program instructions, data files, data structures, and the like.

The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention, or may be known and available to those skilled in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Hardware devices specially configured to store and execute program instructions such as magneto-optical media and ROM, RAM, flash memory and the like. In addition, the above-described medium may be a transmission medium such as an optical or metal wire, a waveguide, or the like including a carrier wave for transmitting a signal specifying a program command, a data structure, and the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like.

The hardware device described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

1 is a block diagram showing a mobile communication system using a femtocell according to an embodiment of the present invention.

2 is a flowchart illustrating a paging method according to an embodiment of the present invention.

3 is a flowchart illustrating a paging method according to an embodiment of the present invention.

4 is a flowchart illustrating a paging method according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

10: mobile terminal 20: femto base station

30: macro base station 40: Internet network

50: base station controller 60: paging controller

70: core network

Claims (10)

In a mobile communication system using a femtocell, A paging controller for transmitting a paging signal to a macro base station corresponding to a paging group number registered by the mobile terminal; A macro base station for registering the femto base station searched by the mobile terminal in a relay target list and relaying the paging signal to a femto base station registered in the relay target list; And Including a femto base station for broadcasting the paging signal relayed from the macro base station to the mobile terminal through a paging channel, And searching for a neighboring base station, when the paging signal is not received from the macro base station, and searching for the femto base station, requesting to register the femto base station as the macro base station. delete The method of claim 1, And wherein the macro base station broadcasts the paging signal to the mobile terminal through a paging channel. The method of claim 1, The femto base station, if the mobile terminal is out of the femtocell for more than a predetermined time, the mobile communication system, characterized in that for the femto base station stored in the relay target list to the registration of the macro base station. The method of claim 1, The macro base station transmits the paging group number when the paging signal is transmitted to the mobile station. And if the paging group number received from the macro base station is different from the registered paging group number, the mobile station performs a location update to the paging controller through the macro base station. A paging method performed by a macro base station in a mobile communication system operating a femtocell, Registering a femto base station receiving a registration request from a mobile station in a relay target list in which a list of femto base stations managed by the macro base station is stored; Receiving a paging signal from a paging controller that controls a paging function of the mobile terminal; Relaying a paging signal to the femto base station using the relay target list; And Broadcasting the paging signal through a paging channel; Registering the femto base station is The mobile terminal searching for a neighbor base station; And And if the paging signal is not received and the femto base station is found as a result of the search of the mobile terminal, requesting the mobile terminal to register the femto base station as the macro base station. delete The method of claim 6, Broadcasting the paging signal through a paging channel The macro base station and the femto base station broadcast the paging signal through the paging channel. The method of claim 6, The femto base station further comprises the step of requesting deregistration of the femto base station stored in the relay target list to the macro base station when the mobile terminal is out of the femtocell for a preset time. The method of claim 6, The macro base station transmits a paging group number when transmitting the paging signal to the mobile station, And if the paging group number received from the macro base station is different from the registered paging group number, the mobile station performs a location update to a paging controller through the macro base station.

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