KR20140084916A - Method and apparatus for scheduling according to subscriber distribution and mobile telecommunication system for the same - Google Patents

Abstract

The present invention relates to a method and an apparatus for scheduling for checking distribution by electric field to which a subscriber belongs and performing efficient scheduling in each case during scheduling with respect to multiple users in a 3rd generation partnership project (3GPP) long term evolution (LTE) mobile communication system. The apparatus for scheduling according to subscriber distribution of the present invention recognizes a user terminal distribution state by electric field, and sets a scheduling algorithm to be used for wireless resource scheduling according to the user terminal distribution state by electric field recognized by a subscriber distribution measurement unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a scheduling method and apparatus according to subscriber distribution, and a mobile communication system for the same. 2. Description of the Related Art [

The present invention relates to a mobile communication system, and more particularly, it relates to a mobile communication system in which, in a 3GPP (Long Term Evolution) mobile communication system, a scheduler for a plurality of users, And a scheduling method and apparatus for performing scheduling.

The mobile communication system has a cell structure for efficient system configuration. A cell is an area that is divided into small areas in order to efficiently use frequencies. A multiple access system typically includes multiple cells. In general, a base station is installed in a cell to relay a terminal.

Scheduler is a part that actually performs scheduling in a base station. It is mainly defined by each vendor rather than defined in the 3GPP standard, and includes core technologies and strategies of each vendor. The types of scheduling can be roughly classified into a round robin scheme, a proportional fair scheme, a maximum C / I scheme, and an equal rate scheduling scheme.

There are advantages and disadvantages to each scheduling algorithm, and there is an advantageous scheduling algorithm depending on how subscribers are distributed in the same cell. However, since the distribution of subscribers in the cell is continuously changed, there is a problem in that it can not efficiently cope with all cases using one algorithm fixedly set in the base station (eNode-B).

US Published Patent US 2012/0026986 A1 (Feb. 2, 2012)

The present invention relates to a scheduling method and apparatus for performing efficient scheduling in each case by checking distributions of electric fields to which a subscriber belongs when scheduling a plurality of users in a GPRS (Third Generation Partnership Project) LTE mobile communication system Lt; / RTI >

A scheduling apparatus according to a distribution of subscribers according to the present invention includes: a subscriber distribution measuring unit for grasping a distribution state of user terminals according to electric fields; And a controller configured to set a scheduling algorithm to be used for radio resource scheduling according to distribution states of user terminals for respective electric fields determined by the subscriber distribution measuring unit.

Also, the mobile communication system of the present invention includes the scheduling device, and performs traffic service between the at least one user terminal and the serving base station using the scheduled radio resources.

Also, the scheduling method according to the distribution of subscribers according to the present invention includes the steps of: a) grasping a distribution state of user terminals according to an electric field; And b) setting a scheduling algorithm to be used for radio resource scheduling according to the distribution state of the user terminal for each electric field.

According to the present invention, the base station data capacity can be maximized by implementing a dynamic scheduling algorithm based on the location distribution of subscribers connected to the base station (eNode-B).

1 is a block diagram showing a configuration of a mobile communication system according to an embodiment of the present invention;
BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a scheduling apparatus,
3 is a flow chart illustrating a scheduling procedure according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

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

As shown in FIG. 1, the mobile communication system includes a 2G mobile communication network such as Global System for Mobile communication (GSM), a code division multiple access (CDMA), a long term evolution (LTE) network, a wireless Internet such as WiFi, (E.g., a 3G mobile communication network such as WCDMA or CDMA2000, a High Speed Downlink Packet Access (HSDPA), or a High Speed (HSUPA) A 3.5G mobile communication network such as Uplink Packet Access (E-DCH), or 4G to be developed in the future), a base station (eNB) 20 and a user equipment (UE) But is not limited thereto.

As shown in FIG. 1, the mobile communication system may include one or more cells, and cells of different types may be mixed in the mobile communication system. The mobile communication system includes a user equipment (UE) 10, a base station (eNB) 20, a self organizing & optimizing network (SON) server 30 and a mobility management entity (MME) . The number of each component shown in FIG. 1 is illustrative, and the number of each component of the mobile communication network in which the present invention can be implemented is not limited to the number shown in the drawings. Cells constituting the mobile communication system can independently have connectivity with the core network.

The base station 20 has a feature of a macro cell base station having a radius of, for example, about 1 km, which can be used in an LTE network, a WiFi network, a WiBro network, a WiMax network, a WCDMA network, a CDMA network, a UMTS network, But is not limited thereto.

The user terminal 10 may be a wireless Internet network such as a GSM network and a CDMA network, a wireless Internet network such as an LTE network and a WiFi network, a portable Internet network such as a WiBro network and a WiMax network, But is not limited to, the characteristics of the mobile terminal.

A management server (OAM server) 50, which is a network management apparatus of the base station, is responsible for managing the configuration information of the base station 20. [ The management server 50 can perform all the functions of the SON server 30 and the MME 40. [

The SON server 30 may include any server that performs the installation and optimization of the base station 20 and provides basic parameters or data necessary for each base station.

The MME 40 may include any entity used for managing call processing and the like of the user terminal 10. [ The MME 40 performs a function of a base station controller (BSC) and can perform resource allocation, call control, handover control, voice and packet processing, and the like to the base station 20 connected thereto.

The types of radio resource scheduling schemes that can be used in the base station 20 can be broadly classified into four schemes to be described below.

1. Round robin scheme: The round robin scheme is a scheme for uniformly allocating radio resources to users in a cell regardless of the channel state of users in the cell. This is a good method only from the viewpoint of the equality between users, but there is a problem that the cell capacity is small because the scheduling is performed without considering the instantaneous channel state. More specifically, the radio bearer scheduler sets a radio bearer waiting for the longest time since the last scheduling grant (grnat) as the highest priority and schedules radio resources. The round robin method can be used for most mobile communication services. However, the round-robin algorithm does not take into account the channel state of each user at all and thus can not obtain the scheduling gain.

2. Proportional fair method: It allocates resources considering the fairness among users in a cell, and considers the instantaneous channel state together. The scheduling of the radio resources is performed considering both the channel state and the time when the user is not received. As the time for which the service is not received becomes longer, the priority increases and the priority and carrier to interference (C / I) Together. The combination of the maximum C / I scheme and the round robin scheme described below satisfies the capacity aspect of the system and the quality of service (QoS) of various users to some extent. It can be divided into proportional fair high, proportional fair medium and proportional fair low according to the degree of fairness.

3. Maximum C / I method: The maximum C / I method is the algorithm with the lowest fairness. When the maximum C / I scheme is used, the scheduling apparatus allocates radio resources to users in the best radio channel environment in order to maximize the capacity of the cell. Here, C / I represents the ratio of the signal power to the interference power. The larger the C / I value, the better the state of the channel. The smaller the C / I value, the better the channel state. However, a user with a poor channel status can not receive and transmit data because the radio resource is not continuously allocated. That is, the maximum C / I scheme does not satisfy the QoS of the entire cell.

4. Equal rate scheduling scheme: When using the uniform rate scheduling scheme, the scheduling device ensures the same average throughput for the flow inside the cell. In other words, in order to satisfy the fairness rate, it is necessary to allocate more radio resources to the users with bad channel condition on average. This results in a downward leveling of the whole in terms of cell average throughput. In other proportional fair scheduling schemes, the balance between cell capacity and cell boundary throughput is sought.

According to the present invention, a dynamic scheduling algorithm based on distribution of a subscriber being currently connected to a base station (eNode-B) and being located in a strong electric field or a weak electric field is implemented and a scheduling algorithm So that the capacity of the base station data can be maximized. In order to implement the embodiment of the present invention, the CQI information transmitted by the UEs is collected to check the number of subscribers per CQI in the base station 20 and the scheduling algorithm of the base station 20 can be changed based on the number of subscribers per CQI .

FIG. 2 is a diagram illustrating a configuration of a scheduling apparatus according to a distribution of subscribers according to an embodiment of the present invention. Referring to FIG.

2, the scheduling apparatus 100 according to the present invention includes a subscriber distribution measuring unit 110, a controller 120, and a scheduling unit 130. In one embodiment, the scheduling apparatus 100 according to the subscriber distribution may be provided in the base station 20 of the mobile communication system.

The subscriber distribution measuring unit 110 measures a channel quality index (CQI) transmitted from the at least one user terminal 10 to the user terminal 10 ) Of the distribution. In one embodiment, the CQI can be determined to be a strong electric field when the CQI value is equal to or greater than 70 dbm, and can be determined to be a weak electric field when the CQI value is less than or equal to 9 dbm, and can be determined as a heavy electric field when the CQI value is greater than 9 dbm and less than 70 dbm. However, the electric field distribution according to the CQI value is not limited to the above embodiment. The subscriber distribution measuring unit 110 receives and stores CQIs periodically reported by the at least one user terminal 10 to the base station 20 and stores CQIs having a CQI value equal to or greater than a predetermined threshold value, The user terminal 10 is distinguished from the user terminal 10 having a CQI value equal to or lower than a threshold value (located in an evil electric field) to determine the number of user terminals 10 distributed by electric field. In one embodiment, the threshold value for distinguishing the weak electric field from the strong electric field can be set to "10 dbm ". However, the threshold value is not limited to the above embodiment. The subscriber distribution measuring unit 110 can determine whether the user terminal 10 is geographically separated from the base station 20 by using the location registration information of each user terminal 10, (For example, 500 m) from the base station 20, it is determined that the terminal is located in the strong electric field system. If the position of the user terminal 10 is located in a region outside the predetermined radius from the base station 20, . In addition, the subscriber distribution measuring unit 110 periodically updates the location of the user terminal 10 to determine whether it is located in a strong electric field or weak electric field. However, the method of measuring the distribution state of the user terminal 10 is not limited to the above-described embodiment.

The control unit 120 sets a scheduling algorithm to be used for radio resource scheduling according to the distribution state of the user terminal 10, which is determined by the subscriber distribution measuring unit 110. [ In one embodiment, when the user terminal 10 located in the strong electric field system is more than the user terminal 10 located in the weak electric field, the control unit 120 assigns the resource allocation priority to the strong electric system subscribers while considering the overall equity at the time of scheduling If the user terminal 10 located in the strong field is less than the user terminal 10 located in the weak field, a proportional fair high algorithm is applied to the evolved field, It is possible to allocate more scheduling resources to the evolved electric subscribers. However, the scheduling algorithm setting method of the controller 120 is not limited to the above-described embodiment.

The scheduling unit 130 may perform radio resource scheduling to the user terminal 10 that the base station 20 manages using the scheduling algorithm set by the controller 120. [ The scheduling unit 130 applies a proportional fairness algorithm when the user terminal 10 located in the strong electric field is more than the user terminal 10 located in the weak electric field under the control of the controller 120, And when the user terminal 10 located in the strong field is less than the user terminal 10 located in the weak electric field, the radio resource is scheduled by applying a proportional fairness algorithm. However, the radio resource scheduling method of the scheduling unit 130 is not limited to the above embodiment.

Meanwhile, the traffic service between the user terminal 10 and the base station 20 can be performed using the scheduled radio resource using the scheduling apparatus 100 according to the distribution of the subscriber by the electric field.

3 is a flow chart illustrating a scheduling procedure according to an embodiment of the present invention.

As shown in FIG. 3, when a multi-user accesses a specific base station (S110), the user terminal 10 periodically transmits CQI or location registration information to the base station 20. FIG. The scheduling apparatus 100 according to the distribution of subscribers determines whether the corresponding user terminal 10 is located in a strong electric field or weak electric field by using the CQI information transmitted from a plurality of user terminals 10, (10) and the number of user terminals (10) located in the weak electric field (S120). The control unit 120 compares the number of the user terminals 10 located in the strong electric field with the number of the user terminals 10 located in the weak electric field S130, 10), a proportional fair high algorithm is applied (S140). If the user terminal 10 located in the strong electric field is more than the user terminal 10 located in the weak electric field, the proportional fair high algorithm is applied ) Algorithm (S150). Thereafter, the scheduling unit 130 may schedule the radio resources to the user terminal 10 using the applied scheduling algorithm (S160).

Although the method has been described through particular embodiments, the method may also be implemented as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with some embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as understood by those skilled in the art. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

10: user terminal 20: base station
30: SON server 40: MME
50: management server 100: scheduling device according to subscriber distribution
110: subscriber distribution measuring unit 120:
130: Scheduling unit

Claims (12)

A scheduling apparatus according to subscriber distribution,
A subscriber distribution measuring unit for measuring a distribution state of a user terminal according to an electric field; And
And a controller configured to set a scheduling algorithm to be used for radio resource scheduling according to distribution states of user terminals for each electric field identified by the subscriber distribution measuring unit. The method according to claim 1,
Further comprising a scheduling unit configured to perform radio resource scheduling to at least one user terminal under the control of the serving base station using the scheduling algorithm set by the control unit. The method according to claim 1,
The subscriber distribution measuring unit,
At least one user terminal receives and stores CQIs periodically reporting to a serving base station, and a user terminal located in a strong field system having a CQI value equal to or higher than a threshold value and a user located in a weak electric field having a CQI value below a threshold value And identifies the number of user terminals distributed by an electric field by classifying the terminals. The method according to claim 1,
The subscriber distribution measuring unit,
Determining a degree of geographical separation from the serving base station using the location registration information of at least one user terminal, determining that the terminal is located in a strong field system if the position of the at least one user terminal is within a predetermined radius from the serving base station And determines that the terminal is located in a weak electric field when the position of the at least one user terminal is located in an area outside a predetermined radius from the serving base station. The method according to claim 1,
Wherein,
If a user terminal located in a strong electric field is more than a user terminal located in a weak electric field, a proportional fair low algorithm that gives a resource allocation priority to a strong user terminal is applied while considering overall equity in scheduling, Wherein when a user terminal located in the weak electric field is less than a user terminal located in the weak electric field, a proportional fair high algorithm is applied to give priority to the user terminal located in the erroneous field. The method according to claim 1,
Wherein the scheduling algorithm comprises:
A round robin scheme, a proportional fair scheme, a maximum C / I scheme, and an equal rate scheme. A mobile communication system,
6. A scheduling apparatus according to any one of claims 1 to 5,
And performs traffic services between the at least one user terminal and the serving base station using the scheduled radio resources. A scheduling method according to subscriber distribution,
a) determining a distribution state of a user terminal according to an electric field; And
and b) setting a scheduling algorithm to be used for radio resource scheduling according to the distribution state of the user terminal for each electric field. 9. The method of claim 8,
c) performing radio resource scheduling to at least one user terminal under the control of the serving base station using the set scheduling algorithm. 9. The method of claim 8,
The step a)
At least one user terminal receives and stores CQIs periodically reporting to a serving base station, and a user terminal located in a strong field system having a CQI value equal to or higher than a threshold value and a user located in a weak electric field having a CQI value below a threshold value And identifying the number of user terminals distributed by an electric field by classifying the terminals. 9. The method of claim 8,
The step a)
Determining a degree of geographical separation from the serving base station using the location registration information of at least one user terminal, determining that the terminal is located in a strong field system if the position of the at least one user terminal is within a predetermined radius from the serving base station And determining that the terminal is located in a weak electric field when the position of the at least one user terminal is located in an area outside a predetermined radius from the serving base station. 9. The method of claim 8,
The step b)
If a user terminal located in a strong electric field is more than a user terminal located in a weak electric field, a proportional fair low algorithm that gives a resource allocation priority to a strong user terminal is applied while considering overall equity in scheduling, Applying a proportional fair high algorithm to a user terminal located in the erroneous field when the user terminal located in the weak electric field is less than the user terminal located in the weak electric field.

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