KR100586236B1 - Handover Control System and Method for Each Device in Mobile Communication Network - Google Patents

Abstract

The present invention relates to a system and method for controlling handover of a terminal in a mobile communication network in which at least two cells having different radii overlap each other.

In the present invention, first, information received from a terminal (IP of a base station and a terminal having the largest received signal strength) is analyzed to determine whether to perform a handover of the terminal. After confirming radio resource states of neighboring base stations according to the determination result, the terminal determines a new base station which is a base station to be handed over according to the confirmed result. Then, the handover process of the terminal is requested to the determined new base station. On the other hand, the handover support method of the old base station in charge of the traffic processing of the cell where the terminal is currently located, and determines the new base station according to the request of the terminal to the mobile base station MAHO (Mobile Assisted Handover) method to handover the terminal If supported, the terminal is handed over in the same manner. That is, the present invention gives priority to the MAHO scheme to control handover for each terminal. Through this, quality of service (QoS) can be improved by reducing data loss and time delay.

Nested Cell, Mobile Terminal, Handover, MAHO, MCHO, NCHO, Quality of Service (QoS)

Description

Handover control system and method for each terminal in mobile communication network {SYSTEM AND METHOD FOR CONTROLLING TERMINAL HAND-OVER OF MOBILE COMMUNICATION NETWORK}

1 is a diagram illustrating a schematic configuration of a mobile communication network according to an embodiment of the present invention.

2 is a diagram illustrating an internal configuration of a handover control system for each terminal according to an exemplary embodiment of the present invention.

3 is a flowchart sequentially illustrating an operation process of a terminal-specific handover control system according to an exemplary embodiment of the present invention.

The present invention relates to a method for controlling a handover of a terminal, and more particularly, to a system and method for controlling handover for each terminal in a mobile communication network in which at least two cells having different radii overlap each other.

In general, in a mobile communication network in which at least two or more cells having different radii overlap each other, hand-over of a terminal occurs frequently.

Such handovers are referred to as Mobile Assisted Handover (MAHO), Mobile Controlled Handover (MCHO), and Network Control Handover (NCHO) (NCHO). )

Specifically, when the terminal transmits all information necessary for handover to a higher layer (for example, a base station), the upper layer selects a target cell according to the received information, and the terminal hands the target cell. It is a way of over.

In addition, the MCHO is a method in which a terminal directly requests a handover as a target cell, and the NCHO is a technique for processing a direct handover by selecting a target cell and selecting a target cell in a network. That is, when the NCHO determines that the network can no longer handle the traffic due to congestion and overload of the traffic, the NCHO hands over all the traffic in service directly to the target cell.

By the way, the existing high-speed communication network mainly used the MCHO of the handover method, because the terminal directly determines whether to perform the handover, the upper layer (base station) must always perform subscriber authentication and encryption of the terminal. That is, since the upper layer regards the terminal as requesting new traffic processing, the subscriber authentication of the terminal must be performed every time.

In addition, the current mobile communication network also has a structure in which cells providing different multimedia services are overlapped with each other, which is also a handover for each terminal according to MCHO.

For this reason, when performing the handover, the fast handover required for ultra-fast data transmission may not be achieved. This, in turn, causes delays and loss of data transmission, leading to lower system quality of service (QoS).

Therefore, in a mobile communication network in which at least two cells having different radii overlap each other, there is an urgent need for a method for quickly handing over a terminal without complicated procedures.

The technical problem to be solved by the present invention is to solve such a problem, the handover for each terminal using a mobile assisted hand-over (MAHO) method in a mobile communication network in which at least two cells having different radii overlap each other The present invention provides a handover control system and a method for each terminal in a mobile communication network capable of providing a high quality service to a terminal by controlling the same.

According to an aspect of the present invention, a handover control system for each terminal in a mobile communication network according to an aspect of the present invention provides a handover of a terminal in an overlapping cell mobile communication network in which at least two cells having different radii overlap. A control system comprising: a neighboring cell search unit for checking a state of radio resources for at least one neighboring base station adjacent to an old base station in charge of traffic processing in a cell in which a terminal is currently located; A new base station determination unit for determining a new base station which is a base station to be handed over according to the checked result, and then requesting handover processing of the terminal to the determined new base station; A handover type checking unit for checking a handover scheme supported by the old base station to the terminal; And performing a handover to handover the terminal to the new base station in the same manner when any one of the identified methods is a mobile assisted handover (MAHO) for handing over the terminal to the new base station according to the request of the terminal. Contains wealth.

In addition, the handover control method for each terminal in a mobile communication network according to an aspect of the present invention is a method for controlling handover of a terminal in an overlapping cell mobile communication network in which at least two cells having different radii overlap. A method comprising: a) identifying a state of radio resources for at least one neighboring base station adjacent to an old base station that is in charge of traffic processing in a cell in which a terminal is currently located; b) after the terminal determines a new base station that is a base station to be handed over, requesting handover processing of the terminal to the determined new base station; c) confirming a handover scheme supported by the old base station to the terminal; And d) handing over the terminal in the same manner when any one of the identified methods is a mobile assisted handover (MAHO) for handing over the terminal to the new base station according to the request of the terminal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification.

1 is a diagram illustrating a schematic configuration of a mobile communication network according to an embodiment of the present invention.

As shown in FIG. 1, the mobile communication network 100 according to an embodiment of the present invention has a structure in which at least two cells having different radii overlap each other, and each cell moves a multimedia service having different characteristics. Provide each to the terminal.

Briefly referring to the functional unit in each cell constituting the above configuration is as follows.

First, a high-speed portable internet network (A) includes a mobile terminal (HMm) 110 and a base station (Radio Station, 120, hereinafter referred to as 'RS'). Includes a terminal-specific handover control system (not shown) according to an embodiment of the.

An embodiment of the present invention provides a handover between a terminal 110 and an RS 120 between a terminal 110 and an RS 120 of the same subnet or between a mobile integration system 150 of a different subnet. Provides a control technique applied to

Specifically, the RS 120 controls signal control and traffic processing, and controls service setting and release messages between the terminal 110 and CN (Core Network, hereinafter referred to as 'CN'). And, it controls the LAM (Local Access Management) 160 that performs resource allocation, release, and authentication for each RS.

The LAM 160 distributes a part of the functions of the MIS 150 that performs authentication, session, and resource management of the CN (B) to the RS 120, which is a base station, and is the most efficient handover processing for the terminal 110. Provide a way.

That is, if all functions are concentrated on CN (B), the session can be established only through MIS 150 when setting all sessions, and the terminal 110 can accommodate the structure of the integrated network. This causes a huge disruption in performance.

Therefore, in the mobile communication network according to an embodiment of the present invention, the LAM 160 basically proposes a hierarchical distributed structure in which authentication and encryption are performed. That is, most of the session setup is a structure that can be authenticated by the LAM (160), the subnet goes to the authentication center of the CN (B) only when the handover between different systems to perform authentication.

As such, a hierarchical distributed structure in which predetermined functions are distributed across the RS 120, the LAM 160, and the like can reduce signaling overhead of a system and can significantly reduce session control time.

In addition, the RS 120 transmits reverse data coming from the terminal 110 to the Internet CN (B) through the MIS 150 and forward data coming from the Internet CN (B) to the terminal 110.

The LAM 160 manages resources of the entire base station in the same subnet, and manages operation status management and maintenance of the base station. Then, the information on the initialization at the system startup and the information about the system shape are transmitted to each of the subsystems, the state information received from each subsystem is collected, and the collected information is retrieved to make various diagnosis.

Global Access Management (GAM) 170 manages the resources of all the base stations included in different subnets, and manages the operation status and maintenance of the base stations.

In addition, the GAM 170 transmits the information on the subnet system initialization and the system shape at the system startup to each subsystem through the MIS 150, collects state information coming from each subsystem, and collects the collected information. Search and make various diagnoses.

In addition, the GAM 170 manages the IP of the terminal 110 and the RS 120 and ensures mobility when handover occurs between different subnets MIS in the Internet network, and performs handover using a mobile IP. Perform. And, in addition to the function of processing the authentication (Authentication) of the terminal to verify the authentication (Authorization) of the terminal and processes the accounting (Accounting) of each terminal.

The MIS 150 is a router of one subnet unit. The MIS 150 manages IP (Internet Protocol) of terminals occurring in the same subnet in association with the LAM 160 and guarantees mobility.

DHCP (Dynamic host Configuration Protocol) 151 dynamically generates, assigns IP, manages and releases IP, and DNS 152 converts a domain name into an address. The home subscriber system (HSS) 153 manages a profile for each subscriber.

Then, a handover control system for each terminal in the mobile communication network having the above configuration will be described.

2 is a diagram illustrating in detail the internal configuration of the handover control system for each terminal according to an embodiment of the present invention.

As shown in FIG. 2, the handover control system 200 for each terminal according to an exemplary embodiment of the present invention includes a handover request receiver 210, an adjacent cell searcher 220, a new base station determiner 230, and a handover. A type checking unit 240 and a handover performing unit 250 are included.

Specifically, first, the handover request receiving unit 210 receives a service request by receiving information necessary for handover control from the terminal 110 (in FIG. 1).

For reference, the terminal 110 measures received signals of neighboring base stations when the signal from the old base station (the base station in charge of the traffic processing of the cell where the terminal is currently located) becomes weak, and the handover request receiver 210 The terminal 110 receives information from the terminal 110 including the neighboring base station having the highest signal and the Internet Protocol (IP) of the terminal.

The neighbor cell search unit 220 analyzes the received information to determine whether to perform the handover of the terminal 110, and then checks the radio resource state of the neighbor base station according to the determination result.

The new base station determiner 230 determines the new base station that is the base station to be handed over by the terminal 110 according to the result of the check, and then requests handover processing of the terminal 110 to the determined new base station.

Then, the new base station establishes a radio link for handover of the terminal 110 and requests the old base station to release the radio link.

As such, the new base station determiner 230 determines the new base station based on the presence or absence of radio resources, which is not limited to the present invention and may determine the new base station based on other parameters in some cases.

Next, the handover type checking unit 240 is a handover method supported by the old base station is MAHO (Mobile Assisted Handover, hereinafter 'MAHO') or MCHO (Mobile Controlled Handover, hereinafter 'MCHO') And NCHO (Network controlled Handover, hereinafter referred to as 'NCHO'). In addition, it is checked whether only roaming is supported, not the handover method described above.

At this time, the handover type checker 240 first checks whether the handover method supported by the old base station is the MAHO method.

For reference, when the terminal transmits all information necessary for handover to a higher layer (for example, a base station), the upper layer determines a target cell (new base station) according to the received information, and the terminal determines the target cell. Handover method. A detailed process will be referred to later through the drawings when explaining the operation process.

In addition, MCHO is a method in which a terminal directly requests handover to a target cell, and NCHO is a technique for handover processing by selecting a target cell and determining a handover in a network. That is, when the NCHO determines that the network can no longer handle the traffic due to congestion and overload of the traffic, the NCHO hands over all the traffic in service directly to the target cell.

And, roaming means that when a terminal user communicates in a different call zone locally, the terminal is notified to the terminal, thereby enabling communication.

The handover performer 250 controls the terminal 110 to handover or handover to the new base station according to the confirmed handover method of the old base station.

At this time, the handover performer 250 first checks whether the handover scheme supported by the old base station is MAHO. As a result of the check, if the old base station supports the MAHO scheme, the terminal 110 can handover in the same manner.

As a result of the check, if the old base station supports the MCHO method, the terminal 110 is handed over according to the MCHO method. In this case, if the old base station supports the old base station, the terminal 110 is handed over according to the MAHO method. That is, the handover performer 250 controls the handover for each terminal by giving priority to the MAHO scheme.

In addition, if the check result indicates that the old base station supports the NCHO method, the terminal 110 is handed over according to the NCHO method.

Finally, as a result of the check, if the old base station supports only roaming, the terminal 110 provides only the mobility by roaming.

As described above, the handover control system for each terminal in the mobile communication network and the method thereof according to an embodiment of the present invention apply the MAHO method to a mobile communication network in which at least two or more cells having different radii overlap each other, and hand by hand for each terminal. Control over.

That is, the present invention can reduce the handover execution time as much as possible by handing the terminal to the new base station through the MAHO method, rather than the MCHO method of performing user authentication and encryption process for each terminal. This can improve quality of service (QoS) and improve system performance by reducing data transmission delays and losses.

Then, the operation process of the handover control system for each terminal constituting the above configuration will be described.

FIG. 3 is a flowchart sequentially illustrating an operation process of the terminal-specific handover control system shown in FIG. 2.

As shown in FIG. 3, first, the handover request receiving unit 210 in the terminal-specific handover control system 200 receives all information necessary for handover from the terminal 110 (S1) and receives a service request (S301). ).

For reference, when the signal coming down from the old base station in charge of traffic processing of the cell in which the cell is currently located is weakened, the base station having the largest size among the measured received signals after measuring the received signals of the adjacent base stations; Information including the Internet Protocol (IP) of the terminal is transmitted to a higher layer (old base station).

That is, the terminal 110 transmits all information necessary for handover to the old base station, so as to request to select a target cell for handover.

Thereafter, the neighbor cell search unit 220 analyzes the received information to determine whether to perform the handover of the terminal 110 (S302), and then checks whether there is a radio resource required for handover for each base station according to the determination result. (S303).

Thereafter, the new base station determiner 230 determines the new base station that is the base station to be handed over by the terminal 110 according to the check result (S304), and then requests handover processing of the terminal 110 to the determined new base station.

Then, the new base station establishes a radio link for handover of the terminal 110 and requests the old base station (the base station in the cell where the terminal is currently located) to release the radio link.

At the same time, the terminal 110 also establishes a radio link for handover to the new base station and negotiates the quality of service through the established radio link. The result of the negotiation is notified to the upper layer.

Thereafter, the handover type checking unit 240 checks whether the handover scheme supported by the old base station is MAHO or MCHO and NCHO. In addition, the handover type confirmation unit 240 confirms whether only roaming is supported, not the handover method (S305).

At this time, the handover type checker 240 first checks whether the handover method supported by the old base station is the MAHO method.

Thereafter, the handover performing unit 250 controls the terminal 110 to handover or handover to the new base station according to the confirmed handover method of the old base station.

In detail, the handover performing unit 250 first checks whether the handover scheme supported by the old base station is MAHO (S306). As a result of the check, if the old base station supports the MAHO scheme, the terminal 110 can make a handover in the same manner (S307).

If the old base station supports the MCHO method (S308), the terminal 110 performs a handover (S309) according to the MCHO method. In this case, if the old base station also supports the old base station, the terminal 110 is supported according to the MAHO method. Hand over.

That is, the handover performer 250 controls the handover for each terminal by giving priority to the MAHO scheme.

In addition, if it is confirmed that the old base station supports the NCHO method (S310), the terminal 110 is handed over (S311) according to the NCHO method, and if the old base station also supports the old base station, the terminal 110 is handed according to the MAHO method. Over.

Finally, if the old base station only supports roaming (S312), the terminal 110 provides only the mobility by roaming (S313).

As described above, the terminal-specific handover control system and method thereof according to an embodiment of the present invention apply a Mobile Assisted Handover (MAHO) scheme to a mobile communication network in which at least two cells having different radii overlap each other. To control handover by terminal.

The drawings and detailed description of the invention are exemplary only, and are used for the purpose of illustrating the invention only, and are not intended to be limiting or to limit the scope of the invention described in the claims. Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

Handover control system and method for each terminal in a mobile communication network according to the present invention by applying a Mobile Assisted Handover (MAHO) method to a mobile communication network in which at least two cells having different radii overlap each other handover for each terminal By controlling this, the quality of service (QoS) can be improved by reducing data transmission delay or loss, and the performance of the system can be improved.

Claims (6)

A system for controlling handover of a terminal in an overlapping cell mobile communication network in which at least two cells having different radii are overlapped, A neighboring cell search unit for checking a state of radio resources for at least one neighboring base station adjacent to an old base station in charge of traffic processing in a cell in which a terminal is currently located; A new base station determination unit for determining a new base station which is a base station to be handed over according to the checked result, and then requesting handover processing of the terminal to the determined new base station; A handover type checking unit for checking a handover scheme supported by the old base station to the terminal; And If any one of the identified methods is a mobile assisted handover (MAHO) for handing over the terminal to the new base station at the request of the terminal, a handover performing unit for handing over the terminal to the new base station in the same manner. Handover control system for each terminal in a mobile communication network comprising a. According to claim 1, The handover type confirmation unit, the scheme supported by the old base station A mobile controlled handover (MCHO) method in which a terminal requests handover processing to a new base station; A network controlled handover (NCHO) scheme in which an old base station determines whether to perform a handover and then handovers the terminal by selecting a new base station according to the determined matters; Terminal-specific handover control system in a mobile communication network to determine whether any one of the roaming (Roaming) to provide the mobility of the terminal. The method of claim 2, The handover performing unit, If the checked method is MCHO (Mobile Controlled Handover), handover the terminal in the same manner, In the case of the network controlled handover (NCHO), handover the terminal in the same manner, In the case of the roaming (Roaming) handover control system for each terminal in a mobile communication network to move the terminal in the same manner. According to claim 1, The adjacent cell search unit, After analyzing the received signal strength of the neighboring base station received from the terminal and the Internet Protocol (IP) of the terminal, handover for each terminal in the mobile communication network to determine whether to perform the handover according to the analysis result Control system. A method of controlling handover of a terminal in an overlapping cell mobile communication network in which at least two cells having different radii are overlapped, a) checking a state of radio resources of at least one neighboring base station adjacent to an old base station in charge of traffic processing in a cell in which a terminal is currently located; b) after the terminal determines a new base station that is a base station to be handed over, requesting handover processing of the terminal to the determined new base station; c) confirming a handover scheme supported by the old base station to the terminal; And d) handing over the terminal in the same manner if any one of the identified methods is a mobile assisted handover (MAHO) for handing over the terminal to the new base station according to the request of the terminal; Handover control method for each terminal in a mobile communication network comprising a. The method of claim 5, In step d), the identified method Handovering the terminal in the same manner when the terminal is in a Mobile Controlled Handover (MCHO) method for requesting handover processing to a new base station; After the old base station determines whether to perform the handover, handovering the terminal in the same manner in the case of a network controlled handover (NCHO) method in which a new base station is selected and handed over to the terminal according to the determined item; And In case of roaming providing mobility of the terminal, moving the terminal in the same manner Handover control method for each terminal in a mobile communication network comprising a.

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