KR20070013763A - System and method for a transmission/receiving of data packet corresponding radio access station load in a broadband wireless access communication system - Google Patents

Abstract

A system and a method for transmitting/receiving data packets according to the load of a RAS(Radio Access Station) in a BWA(Broadband Wireless Access) communication system are provided to increase the resource efficiency of RASs and to improve the speed for data packet transmission to subscriber stations by differently executing scheduling by using different FAs in an IEEE 802.16d communication system. An IEEE 802.16d communication system comprises an ACR(Access Control Router)(110), a serving RAS(120), a target RAS(130), and a subscriber station(140). The ACR(110) manages information on the RASs(120,130), executes routing for the data packets transmitted/received through the RASs(120,130), and manages radio access with the subscriber station(140). The RASs(120,130) manage radio access with the subscriber station(140). In this case, the serving RAS(120) provides the present service to the subscriber station(140), and the target RAS(130) provides an additional service according to a scheduling of the ACR(110).

Description

System and method for transmitting / receiving data packet according to load of base station in broadband wireless access communication system

1 is a view schematically showing the structure of an IEEE 802.16d communication system according to an embodiment of the present invention;

2A to 2C schematically illustrate a method of transmitting data packets of an ACR according to an embodiment of the present invention;

3 is a diagram schematically illustrating an operation of combining a data packet received by a subscriber station according to an embodiment of the present invention;

4 is a diagram schematically showing the internal structure of each object in the IEEE 802.16d communication system according to an embodiment of the present invention;

5 is a diagram schematically illustrating an internal configuration of a subscriber station in an IEEE 802.16d communication system according to an embodiment of the present invention;

6 is a diagram illustrating a data packet transmission control process according to RAS load of an ACR in an IEEE 802.16d communication system according to an embodiment of the present invention.

The present invention relates to a broadband wireless access (BWA) communication system, and more particularly, to a scheduling system and method for load distribution of an access control router in an 802.16d communication system.

In the 4th Generation (hereinafter, referred to as '4G') communication system, a next generation communication system, providing users with services having various speeds of quality of service (hereinafter referred to as 'QoS') to users. Active research is in progress. In particular, in 4G communication systems, broadband wireless such as a wireless local area network (hereinafter, referred to as 'LAN') system and a wireless metropolitan area network (hereinafter, referred to as 'MAN') system are used. Researches are being actively conducted to support high-speed services in a form of guaranteeing mobility and QoS in an access communication system, and a representative communication system is an IEEE (Institute of Electrical and Electronics Engineers) 802.16d communication system.

The IEEE 802.16d communication system is referred to as Orthogonal Frequency Division Multiplexing (OFDM) / orthogonal to support a broadband transmission network in a physical channel of the wireless MAN system. A communication system employing an Orthogonal Frequency Division Multiple Access (hereinafter, referred to as 'OFDMA') scheme. The IEEE 802.16d communication system is a system currently considering only a single cell structure and a state in which a subscriber station (SS) is fixed, that is, a state in which the mobility of the subscriber station is not considered at all.

The IEEE 802.16d communication system typically includes the subscriber station, a radio access station (hereinafter referred to as "RAS"), which is a base station (BS) providing a service to the subscriber station, and It is configured to include an access control router (Access Control Router, hereinafter referred to as "ACR") that controls the RAS.

Radio resources are limited in the IEEE 802.16d communication system having the above configuration. Therefore, when a high-end user or a user who requires a lot of bandwidth is concentrated, the base station RAS is saturated and a problem occurs in the service. At this time, in the prior art, to solve the saturation state of the RAS as described above, to increase the expansion or FA of the RAS in the system.

That is, in the prior art, a method of increasing the capacity of the base station through a method of adding an FA in the base station is used. However, this method has been possible in a conventional voice-centric network, but there is a problem in that data transmission is limited in a wireless situation in which bandwidth is limited as in the 802.16d communication system. In addition, since the FA must be additionally added as described above, there is a problem in that an additional cost is burdened. The domestic WiBro trend is currently available at a maximum theoretical 18Mbps of 10MHz per 1FA bandwidth. If the value is assumed that one user, that is, one subscriber terminal uses 300k video and 100k, only four users, that is, the subscriber terminal, can service. In addition, the suburban area provides a smooth service using a wired DSL network for a small number of subscribers. However, this requires additional FA or base station to provide services to subscribers located in the far distance, which has a problem of requiring high facility investment cost.

As described above, the existing voice-oriented communication system has a structure that can provide services to a large number of users with less radio resources. At this time, when the high-end users or users who require a lot of bandwidth are concentrated, the FA extension method is used to overcome resource limitations. However, in the service for transmitting a lot of data as described above, due to the limitation of radio resources, it is difficult to service a large amount of data, there is a problem that high-quality transmission service is impossible.

Accordingly, an object of the present invention is to provide an efficient scheduling system and method that can reduce the load of a base station in a broadband wireless access communication system.

Another object of the present invention is to provide an efficient scheduling method of an access control router in a broadband wireless access communication system.

It is still another object of the present invention to provide a system and method for transmitting resources through at least one radio access station by using different frequencies in an access control router when certain resources are transmitted in a broadband wireless access communication system.

Another object of the present invention is to provide a scheduling system and method that can provide a service using a neighbor base station without FA expansion by dividing and transmitting resources through at least one radio access station using different frequencies in an access control router. Is in.

Method according to an embodiment of the present invention for achieving the above objects; A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighboring RAS, in a scheduling method for data packet transmission, if a load abnormality of the serving RAS serving a subscriber station is detected, Dividing a data packet targeted to the subscriber station into a first data packet and a second data packet, allocating the first data packet to the serving RAS, and allocating the second data packet to the adjacent RAS. And then scheduling the transmission to the subscriber station through different frequency bands. And it characterized in that.

Method according to an embodiment of the present invention for achieving the above objects; Broadband wireless access communication including subscriber stations, a plurality of radio access stations (RAS) providing services to the subscriber terminals, and an access control router (ACR) for controlling the RASs. In the system, in the scheduling method for data packet transmission, if the load of a particular RAS in service to the subscriber station increases above a predetermined threshold, at least one adjacent RAS to the data packet targeting the subscriber station; The data packet is divided in correspondence with each other, and the divided data packets are transmitted through different frequency bands through the at least one adjacent RAS.

Method according to an embodiment of the present invention for achieving the above objects; A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighboring RAS, in a data packet transmission method, when the serving RAS detects a problem with a service to the subscriber station, And informing the ACR of a load abnormality thereof, and transmitting the M-th data packet obtained by dividing the data packet targeted to the subscriber station according to the control of the ACR to the subscriber station. It is done.

Method according to an embodiment of the present invention for achieving the above objects; A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling an adjacent RAS, a method of transmitting a data packet, the method comprising: receiving a notification of transmitting a data packet from the ACR to the subscriber station; And transmitting the K-th data packet obtained by dividing the data packet targeting the subscriber station to the subscriber station according to the control of the ACR.

Method according to an embodiment of the present invention for achieving the above objects; A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a wideband wireless access communication system including an access control router (ACR) for controlling a neighboring RAS, a method of receiving a data packet includes: a data packet divided by a data packet transmitted separately from the serving RAS and the target RAS; Receiving a first data packet and a second data packet excluding the first data packet, and combining the received first data packet and the second data packet to restore the original data packet. It is done.

Method according to an embodiment of the present invention for achieving the above objects; A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighboring RAS, in the method of receiving a data packet, when the split transmission instruction message of the data packet is received from the ACR, the instruction message is transmitted. Acknowledging the fragmentation transmission of the data packet correspondingly, transmitting a response message corresponding to the indication message, and thereafter, the data packet targeting the subscriber station is divided from the serving RAS according to the control of the ACR. Receiving the first data packet and dividing the data packet from the adjacent RAS; And receiving a second data packet excluding the first data packet, and combining the received first data packet and the second data packet to restore the original data packet.

Method according to an embodiment of the present invention for achieving the above objects; A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling an adjacent RAS, in a data packet transmission / reception method, the ACR receives status information transmitted from the serving RAS, and the status information. In response to confirming that the serving RAS is more than the load, the step of notifying in advance that the data packet is transmitted to the subscriber station via the serving RAS in advance, and the ACR removes the data packet targeted to the subscriber station; The first data divided into one data packet and the second data packet, and divided by the serving RAS. Allocating a frequency to be used for kit transmission, a frequency to be used to transmit the second data packet divided by the adjacent RAS, and the ACR assigns the first data packet to the serving RAS and the second data packet. Transmitting the first data packet to the subscriber station through a frequency band allocated to the subscriber station; and transmitting the first data packet to the subscriber station through a frequency band allocated thereto through the adjacent RAS. The neighbor RAS transmits the second data packet to the subscriber station through the frequency band allocated thereto, and the subscriber station receives the first data packet through the frequency band used by the serving RAS. After receiving the second data packet through a frequency band used by an adjacent RAS, the first data And combining the packet and the second data packet to restore the packet to the data packet.

A system according to an embodiment of the present invention for achieving the above object; A system for transmitting and receiving data packets in a broadband wireless access communication system, when detecting a load abnormality of a serving radio access station (RAS) currently connected to a subscriber station, removes a data packet targeted to the subscriber station. The first data packet and the second data packet are divided into one data packet and the second data packet, and the first data packet and the second data packet are allocated to different serving frequency bands to the serving RAS and the adjacent RAS. An access control router (ACR) for controlling a packet and a second data packet to be transmitted to the subscriber station, and periodically transmitting its status information to the ACR, and detecting the abnormal status of the ACR. Request load sharing, and load the first data packet at the allocated frequency according to the control of the ACR. If the serving RAS is transmitted to the subscriber station and the ACR is notified of the transmission of the second data packet in which the data packet targeting the subscriber station is divided, the second at the allocated frequency under the control of the ACR. The first RAS receives the first data packet through a frequency used by the serving RAS and the neighbor RAS corresponding to the control of the ACR, and transmits the data packet to the subscriber station. And a subscriber station receiving a second data packet, combining the received first data packet and the second data packet, and restoring the original data packet.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

The present invention proposes a scheduling apparatus and method in a broadband wireless access (BWA) communication system, for example, an Institute of Electrical and Electronics Engineers (IEEE) 802.16d communication system. In particular, the present invention relates to a scheduling system and method for load distribution of an access control router (hereinafter referred to as ACR) in an IEEE 802.16d communication system. In this case, in order to perform scheduling in the ACR, a resource (eg, a sub-carrier) different from a serving radio access station (hereinafter referred to as 'RAS') and a target RAS is selected. We propose a system and method for performing scheduling.

That is, the proposed invention provides efficient transmission and service of data packets transmitted to a subscriber station by scheduling each of two RASs in a ACR in a different IEEE 802.16d communication system. Typically, the use of radio resources is limited in the IEEE 802.16d communication system. Therefore, when a high-end user or a user who requires a lot of bandwidth is concentrated, the base station RAS is saturated, which causes a problem in providing a service. In order to solve this problem, conventionally, a method of increasing the capacity of the RAS by increasing a base station or increasing FA is used. However, when the base station or the FA is expanded as described above, problems as described in the related art may occur.

In this regard, the present invention proposes a scheduling method using a serving RAS currently serving a subscriber station and a RAS adjacent to the serving RAS without increasing the base station or FA. In other words, the present invention proposes a scheduling scheme of ACR that allows a subscriber station to receive different data asynchronously through different frequencies in two RASs using the serving RAS and the existing neighbor RAS, for example, a target RAS. do. Here, the other frequency refers to operating two or more different FA or frequency reuse rate.

As described above, in the present invention, for convenience of description, the IEEE 802.16d communication system is described as an example. However, the method proposed by the present invention may be applied to other communication systems as well as the IEEE 802.16d communication system.

1 is a view schematically showing the structure of an IEEE 802.16d communication system according to an embodiment of the present invention.

Referring to FIG. 1, FIG. 1 is a diagram illustrating a configuration in which a data packet is asynchronously transmitted to a subscriber station using two RASs, for example, a serving RAS and a target RAS in transmitting a data packet. to be. Referring to FIG. 1, the IEEE 802.16d communication system includes an ACR 110, a serving RAS 120, a target RAS 130, and a subscriber station 140. That is, the IEEE 802.16d communication system uses the same principle as a hot spot, and the IEEE 802.16d communication system includes two types, namely, the ACR 110 and the RAS 120 and 130. It is constructed.

The ACR 110 manages information about RASs managed by itself, for example, the serving RAS 120 and the target RAS 130, and is transmitted and received to the serving RAS 120 and the target RAS 130. An information signal, for example, performs routing for a data packet, and manages a wireless connection with the subscriber station 140.

The RASs 120 and 130 manage the wireless connection with the subscriber station 140. In this case, the serving RAS 120 is a RAS currently providing service to the subscriber station 140, and the target RAS 130 is configured to schedule the ACR 110 with respect to the subscriber station 140. RAS to provide additional services.

Here, the signal transmission and reception between the serving RAS 120 and the target RAS 130 and the subscriber station 140 uses Orthogonal Frequency Division Multiple Access (hereinafter, referred to as 'OFDMA'). It is done by In addition, the OFDMA is composed of subcarriers determined according to a fast Fourier transform (hereinafter, referred to as 'FFT') size during each symbol time. The subcarrier is further divided into several subchannels. At this time, the information signal to be transmitted to each subcarrier is raised. That is, unlike the conventional Code Division Multiple Access (CDMA) scheme, the subcarrier exists because the OFDMA uses a multi-carrier.

In addition, in FIG. 1, the ACR 110 manages only the serving RAS 120 and the target RAS 130, and the serving RAS 120 and the target RAS 130 manage the subscriber station 140. Although the management case is illustrated, the ACR 110 may manage a plurality of RASs, and the serving RAS 120 and the target RAS 130 may also manage a plurality of subscriber stations.

In the present invention, the ACR 110 detects the load of each of the RAS, for example, the serving RAS 120 and the target RAS 130, and correspondingly to the serving RAS 120 and the target RAS 130, respectively. Perform another scheduling. That is, the ACR 110 separates the predetermined data packet transmitted to the serving RAS 120 and the target RAS 130 into different data packets through the different scheduling. Thereafter, the ACR 110 transmits the separated different data packets using different frequencies. Then, each of the RASs, that is, the serving RAS 120 and the target RAS 130, transmits the separated respective data packets to the subscriber station 140 through different FAs.

The scheduling operation proposed by the present invention will now be described with reference to FIG. 1.

Prior to describing the operation according to the present invention, the following conditions are assumed to support the present invention as described above. That is, it is assumed that the subscriber station 140 is a terminal capable of multi-input multi-output (hereinafter referred to as 'MIMO') and can receive different frequencies using different antennas. In addition, since the subscriber station 140 currently receives a service from the serving RAS 120, the subscriber station 140 receives a data packet from the serving RAS 120.

At this time, while the serving RAS 120 is providing a service to the subscriber station 140, if the resources of the serving RAS 120, for example, the bandwidth is insufficient, the serving RAS 120 is predetermined information This fact is notified to the ACR 110 through a message. At this time, the ACR 110 is periodically provided with the load information of each RAS managed by itself, for example, the serving RAS 120 and the target RAS 130, thereby monitoring the load of each RAS. Since the relationship between the ACR 110 and each of the RASs will be described later, a detailed description thereof will be omitted.

Then, the ACR 110 receives the information message transmitted from the serving RAS 120 and, in response to the received message, provides a service to the subscriber station 140, for example, the neighboring base station, for example, the target RAS. Search 130. Thereafter, the ACR 110 schedules a data packet targeting the subscriber station 140 to transmit the data packet to be transmitted through the serving RAS 120 and the data packet to be transmitted through the target RAS 130. Divide into In this case, the ACR 110 divides the data packet to be different from the data packet to be transmitted to the other RAS without being contiguous with the same one RAS, for example, to transmit the data packet to the serving RAS 120. do.

Subsequently, the ACR 110 schedules the serving RAS 120 and the target RAS 130 to divide and transmit data packets transmitted to the subscriber station 140 using different frequency bands. For example, the ACR 110 transmits a data packet through 1FA through the serving RAS 120 and transmits a data packet through 3FA through the target RAS 130.

Then, the subscriber station 140 receives data packets separately transmitted from the serving RAS 120 and the target RAS 130, respectively, and combines the received data packets to restore original data packets. . In this case, data packets transmitted from the serving RAS 120 and the target RAS 130 are received asynchronously. Since a description of the reception operation of the subscriber station 140 will be described later, a detailed description thereof will be omitted.

On the other hand, as shown in FIG. 1, FIG. 1 is a service method provided by each RAS, for example, the serving RAS 120 and the target RAS 130, in the form of a sector or an omni. To provide services. In the present invention, in order to provide an effective service, the RAS service area that is as wide as possible to each other is configured to exist. Therefore, the type of service proposed in the present invention is preferably applied to suburban areas rather than urban areas.

Next, an operation of dividing and transmitting a data packet targeting the subscriber station 140 in the ACR 110 will be described with reference to FIGS. 2A through 2C.

2A to 2C are schematic diagrams illustrating a data packet transmission method of an ACR according to an embodiment of the present invention. In particular, FIG. 2A to FIG. 2C illustrate a method of splitting the data packet in the ACR and transmitting the split data packet to each RAS according to the method of transmitting the data packet.

As shown in FIG. 2A to FIG. 2C, FIG. 2A illustrates a case in which the ACR transmits a data packet using only the serving RAS, and FIG. 2B illustrates a case in which the ACR transmits a data packet using only the target RAS. 2C illustrates a case in which the ACR divides and transmits a data packet for each RAS according to the load of each RAS.

2A to 2C, first, as shown in FIG. 1, a data packet targeting the subscriber station 140 includes a data packet unit # 1 and a data packet unit #. 2, data packet unit # 3, data packet unit # 4, data packet unit # 5, and data packet unit # 6.

Then, the ACR 110 transmits the data packet to the subscriber station 140 through scheduling as in the three schemes as shown below.

First, as shown in FIG. 2A, the ACR 110 schedules data packets to be transmitted to only one RAS, for example, the serving RAS 120. That is, in the initial data transmission, a data packet is transmitted using one RAS as a general transmission method shown in the IEEE 802.16d communication system. In this case, when the bandwidth of the serving RAS 120, which is currently providing the service to the subscriber station 140, is sufficient, the RAS schedules the data packet to be transmitted by the general method as described above. Then, the subscriber station 140 receives the transmitted data packet only through the serving RAS 120. That is, the subscriber station 140 transmits a data packet, that is, a data packet unit # 1, a data packet unit # 2, a data packet unit # 3, a data packet unit # 4, a data packet unit # 5, and a data packet. 텃 packet unit # 6 is received via the serving RAS 120.

Secondly, as shown in FIG. 2B, the ACR 110 schedules data packets to be transmitted to only one RAS, for example, the target RAS 130. That is, when a data packet is transmitted using the RAS currently serving the subscriber station 140, for example, when the serving RAS 120 transmits a data packet, the serving RAS 120 does not have a bandwidth to be allocated due to an increase in bandwidth. The RAS 120 schedules a call to the RAS adjacent to the RAS 120 and transmits the data packet to the target RAS 130. Then, the subscriber station 140 transfers the call connected to the serving RAS 120 to the target RAS 130 by the scheduling of the ACR 110, and then transmits the call only through the target RAS 130. Receive the data packet. That is, the subscriber station 140 transmits a data packet, that is, a data packet unit # 1, a data packet unit # 2, a data packet unit # 3, a data packet unit # 4, a data packet unit # 5, and a data packet. Packet unit # 6 is received via the target RAS 130.

Third, as shown in FIG. 2C, the ACR 110 schedules data packets using two RASs, for example, a serving RAS 120 and a target RAS 130. Such a method can be classified into a dynamic transmission method and a static transmission method.

The dynamic transmission method is a transmission method according to the load balance of each RAS, and monitors the load balance of two RASs, for example, the serving RAS 120 and the target RAS 130. At this time, if either RAS load increases more than a certain value, it is scheduled to separate and transmit data packets transmitted to at least one or more general users, for example, subscriber stations to the two RAS. That is, in the dynamic transmission method, the ACR 110 adjusts the load of each RAS to transmit data packets.

The static transmission method is a RAS currently serving the subscriber station 140, for example, if the load of the serving RAS 120 increases above a certain value, the adjacent RAS automatically, for example, the data using the target RAS (130) Schedule the packet to be sent separately. That is, in the static transmission method, the ACR 110 divides and transmits data packets using adjacent RASs according to the load of the serving RAS 120, thereby reducing the load of the serving RAS.

The third transmission method, that is, a method of dividing and transmitting data packets using at least two or more RASs will be described in more detail as follows.

First, the ACR 110 transmits the data packet unit # 1, the data packet unit # 2, and the data packet unit # 4 of the data packet targeted to the subscriber station 140 through the serving RAS 120. The data packet unit # 3, the data packet unit # 5, and the data packet unit # 6 are configured as data packets to be transmitted through the target RAS 130. Accordingly, the data packet units in the data packet transmitted to the subscriber station 140 through the serving RAS 120 and the target RAS 130 become different data packet units.

As described above, when the data packet to be transmitted to the subscriber station 140 through the serving RAS 120 and the target RAS 130 is determined by the control of the ACR 110, the serving RAS 120 and Each of the target RAS 130 transmits a corresponding data packet to the subscriber station 140 through subcarriers in each of the serving RAS 120 and the target RAS 130.

Here, the subcarriers used to transmit the corresponding data packet from the serving RAS 120 to the subscriber station 140 and the corresponding data packet from the target RAS 130 to the subscriber station 140 are transmitted. The subcarriers used for subcarriers are subcarriers having physically different frequencies. For example, 1FA is used to transmit the corresponding data packet from the serving RAS 120 to the subscriber station 140, and 3FA is used to transmit the corresponding data packet from the target RAS 130 to the subscriber station 140. By using, each of the serving RAS 120 and the target RAS 130 to transmit each data packet using a different frequency band.

Then, the subscriber station 140 combines the data packets received through the subcarriers of each of the serving RAS 120 and the target RAS 130 to target the subscriber station 140 itself. Restore the original data packet. Hereinafter, a reception data packet combining operation of the subscriber station 140 will be described with reference to FIG. 3.

3 is a diagram schematically illustrating an operation of combining a data packet received by a subscriber station according to an embodiment of the present invention.

Referring to FIG. 3, as described in FIGS. 1 and 2, the subscriber station 140 includes subcarriers of different frequency bands, for example, 1FA and 3FA, of the serving RAS 120 and the target RAS 130, respectively. Combining the data packets received through them to restore the original data packet targeting the subscriber station 140 itself. That is, the subscriber station 140 receives a data packet including a data packet unit # 1, a data packet unit # 2, and a data packet unit # 4 from the serving RAS 120 through 1FA, and receives the target RAS. The data packet including the data packet unit # 3, the data packet unit # 5, and the data packet unit # 6 is received from the 130 through 3FA.

The subscriber station 140 combines the data packet received from the serving RAS 120 and the data packet received from the target serving RAS 130 to reconstruct the original data packet, that is, data packet unit # 1 and data. The data packet including the packet unit # 2, the data packet unit # 3, the data packet unit # 4, the data packet unit # 5, and the data packet unit # 6 is restored.

As described above, the subscriber station 140 receives data packets from only one RAS or data packets that are divided and transmitted from two or more RASs according to the scheduling method of the ACR 110. After combining, the original data packet is restored and the data packet receiving operation targeting itself is completed.

4 is a diagram schematically showing the internal structure of each object in the IEEE 802.16d communication system according to an embodiment of the present invention.

Referring to FIG. 4, the IEEE 802.16d communication system includes an ACR 400, a serving RAS 420, a target RAS 440, and a subscriber station 460 as described in FIG. 1. . In FIG. 4, each object of the IEEE 802.16d communication system, that is, the ACR 400, the serving RAS 420, the target RAS 440, and the subscriber station 460 communicate with each other according to the IEEE 802.16d communication described with reference to FIG. 1. Each object of the system, that is, the same as the ACR (110) and the serving RAS (120), the target RAS (130) and the subscriber station 140, but only for the convenience of description it is noted that the reference numerals are set differently do.

First, the ACR 400 includes a packet divider 401 and a RAS arranger 403. When the ACR 400 detects that a load occurs in the serving RAS 420 currently providing the subscriber station 460, the ACR 400 may provide an adjacent base station that can provide the service to the subscriber station 460. The target RAS 440 information is detected. In this case, the ACR 400 of the serving RAS 420 currently providing services to the subscriber station 460 through the state information periodically reported by the serving RAS 420 as described in FIG. 1. The state can be detected.

Thereafter, when a data packet targeting the subscriber station 460 is generated, the ACR 400 divides the generated data packet through the packet divider 401. That is, when the packet divider 401 generates a data packet to be transmitted, the packet divider 401 inputs the data packet to be transmitted, and corresponds to the serving RAS 420 and the state information, for example, FA information of the serving RAS 420 and the target RAS 440. The data packet is divided into data packets to be transmitted through the target RAS 440. Thereafter, the divided data packets are output to the RAS arranger 403. The RAS arranger 403 arranges the data packets divided by the packet divider 401 and transmits them to the corresponding RAS. That is, the RAS arranger 403 transmits a data packet to be transmitted through the corresponding FA of the serving RAS 420 to the serving RAS 420 and a data packet to be transmitted through the FA of the target RAS 440. Is transmitted to the target RAS 440.

Meanwhile, the serving RAS 420 includes a predetermined transmitter 421, and the target RAS 440 includes a predetermined transmitter 441. First, when the serving RAS 420 receives a predetermined data packet from the RAS arranger 403 of the ACR 400, the serving RAS 420 transfers the received data packet to the transmitter 421. The transmitter 421 then transmits the received data packet to the subscriber station 460. In addition, when the target RAS 440 receives a predetermined data packet different from the data packet transmitted from the RAS arranger 403 of the ACR 400 to the serving RAS 420, the target RAS 440 receives the received data packet. Transfer to the transmitter 441. The transmitter 441 then transmits the received data packet to the subscriber station 460.

The subscriber station 460 includes a receiver 461 and a buffer 463. The receiver 461 receives data packets from the serving RAS 420 and the target RAS 440, and combines each received data packet from the serving RAS 420 and the target RAS 440. After inning, the original data packet is restored to the buffer 463. The buffer 463 buffers the data packet output from the receiver 461 and then accumulates the original data packet finally completed.

Hereinafter, a detailed configuration of the subscriber station among the objects described with reference to FIG. 4 and an operation process thereof will be described with reference to FIG. 5.

5 is a diagram illustrating a detailed configuration of a subscriber station in an IEEE 802.16d communication system according to an embodiment of the present invention.

Before describing FIG. 5, it is assumed that the subscriber station according to the embodiment of the present invention as described above is a subscriber station capable of MIMO and can receive different frequencies using different antennas.

Referring to FIG. 5, FIG. 5 combines the data packet transmitted from the serving RAS and the target RAS through the detailed configuration of the subscriber station shown in FIG. 4 and the above configuration and restores the original data packet. It is shown to explain the process. As shown in FIG. 5, the FA controller 501, the FA assigner 503, the first antenna 505, the first receiver 507, And a second antenna 509, a second receiver 511, a packet multiplexer 513, and a buffer 515. In FIG. 5, the subscriber station of the IEEE 802.16d communication system is the same as the subscriber station of the IEEE 802.16d communication system described with reference to FIG. 4, and only the reference numerals are different for convenience of detailed configuration and operation of the subscriber station. It should be noted that it is set.

First, the FA controller 501 is a block for determining whether to change the FA. That is, when the FA controller 501 receives a predetermined FA control message, for example, a load share request message from the ACR, the FA controller 501 corresponds to the first antenna 505 and the second antenna in response to the received message. Check the information of the FA received through the 509. Thereafter, the FA control information is transmitted to the FA allocation unit 503 in correspondence with the confirmed information. When the FA allocation unit 503 receives the FA control information from the FA controller 501, the FA allocation unit 503 allocates an FA to be received by the first receiving unit 507 and the second receiving unit 511 according to the FA control information. do.

For example, when the FA control request message is received from the ACR, the FA controller 501 checks information of FAs received through the first antenna 505 and the second antenna 509, respectively. When the FA controller 501 determines that 1FA is received through the first antenna 505 and 3FA is received through the second antenna 509, the FA controller 503 transmits the FA reception information to the FA allocation unit 503. To send). Then, the FA allocation unit 503 receives only the frequency corresponding to the 1FA through the first receiving unit 507 through the first antenna 505 and through the second receiving unit 511. The second antenna 509 allocates a FA to receive only a frequency corresponding to the 3FA. Thereafter, only the data packet loaded in the 1FA is received through the first antenna 505, and only the data packet loaded in the 3FA is received through the second antenna 509.

As described above, the first receiver 507 controls the reception frequency band of the first antenna 505 corresponding to FA information allocated from the FA assignment unit 503, for example, 1FA, and then the first After receiving a data packet of a corresponding frequency band, for example, 1FA, received through the antenna 505, the packet is transmitted to the packet multiplexer 513.

As described above, the second receiver 511 controls the reception frequency band of the second antenna 509 in response to FA information allocated from the FA assignment unit 503, for example, 3FA, and then the second After receiving a data packet of a corresponding frequency band, for example, 3FA, received through the antenna 509, the packet is transmitted to the packet multiplexer 513.

Here, each data packet transmitted from the first receiver 507 and the second receiver 511 is asynchronously received through the first antenna 505 and the second antenna 509. The packet is asynchronously transmitted to the packet multiplexer 513. However, since the present invention is not limited thereto, data packet transmission by the first receiver 507 and the second receiver 511 may be synchronously transmitted.

The packet multiplexer 513 receives the data packets divided and transmitted by the first receiver 507 and the second receiver 511, and combines the received data packets. After mixing (mixing) into a data packet of the transmitted to the buffer 515. That is, the packet multiplexer 513 is different from each other at a different center frequency, such as a 1FA data packet received through the first antenna 505 and a 3FA data packet received through the second antenna 509. The data packets transmitted through the antennas are combined into original data packets through combining. Then, the buffer 515 buffers and accumulates the data packet transmitted from the packet multiplexer 513.

6 is a diagram illustrating a data packet transmission control process according to a RAS load of an ACR in an IEEE 802.16d communication system according to an embodiment of the present invention.

Before describing FIG. 6, the ACR 650 periodically receives status information of each RAS managed by itself, for example, the serving RAS 610 and the target RAS 630. In addition, if a load occurs in the serving RAS 610 currently providing a service to the subscriber station 670 or more, if the automatic notification of the fact through a predetermined message, and receives this state for each RAS Will be managed.

That is, the ACR 650 receives a status message periodically transmitted from each RAS managed by the ACR 650, manages information on each RAS, and generates a specific RAS, for example, a load exceeding a predetermined threshold according to a system setting. When the serving RAS 610 is detected, load distribution scheduling is performed for the specific RAS.

First, each of the RASs belonging to the management area in the ACR 650, for example, the serving RAS 610 and the target RAS 630 periodically sends a load confirm message (load_confirm) to confirm their current status. 650) (step 601, step 603). In this case, although the load confirmation message is periodically transmitted, the RASs automatically generate the load confirmation message when the load increases more than a certain amount while providing a service to a predetermined subscriber station. Of course, it can be configured to request its own load distribution by sending to.

Hereinafter, the RAS currently serving the subscriber station will be referred to as the serving RAS 610, and the ACR 650 will be described on the assumption that the load confirmation message is received from the serving RAS 610. In this case, the process of transmitting the load confirmation message of the target RAS 630 illustrated in FIG. 6, that is, step 603 may be omitted.

Referring to FIG. 6, when the load confirmation message is received from the serving RAS 610 (step 601), the ACR 650 checks the load on the serving RAS 610 (step 605). That is, the ACR 650 compares the load of the serving RAS 610 with a predetermined threshold value N according to a system setting through a load confirmation message. In this case, the load confirmation message may include the current load information of the serving RAS 610 itself, for example, a load value.

Next, the ACR 650 disregards the request of the serving RAS 610 when the comparison result indicates that the load of the serving RAS 610 is not greater than or equal to a predetermined threshold, that is, greater than or equal to the predetermined threshold. However, when the load of the serving RAS 610 is greater than or equal to the predetermined threshold, that is, more than the predetermined threshold value, the ACR 650 receives the subscriber terminal currently receiving the service with the serving RAS 610 ( In operation 670, the data packet is divided and transmitted through a predetermined message (steps 607 and 609). That is, when the ACR 650 detects that the load of the serving RAS 610 is greater than or equal to a predetermined load, the ACR 650 shares the load with the subscriber station 670 through the serving RAS 610 to which the subscriber station 670 is connected. A request (loadshare_request) message is transmitted to indicate the preparation for splitting and sending the data packet.

Next, when the subscriber station 670 receives the load sharing request message, the subscriber station 670 recognizes that the received data packet will be divided and transmitted, and the serving sharing response message (loadshare_response) message is provided in response to the load sharing request message. The ACR 650 is transmitted through the RAS 610 (steps 611 and 613).

When the ACR 650 receives the load sharing response message in response to the data packet division transmission from the subscriber station 670, the ACR 650 allocates a frequency band, that is, FA, to be used by the serving RAS 610 for data packet transmission. (Step 615). That is, when the ACR 650 receives the load sharing response message from the subscriber station 670, the ACR 650 informs the frequency band information to be used by the serving RAS 610 through a FA assignment message.

When the serving RAS 610 receives the FA assignment message from the ACR 650, the serving RAS 610 transmits a FA assignment confirmation (FA_assign_confirm) message to the ACR 650 in response to the FA assignment message (step 617). Then, when the ACR 650 receives the FA assignment confirmation message from the serving RAS 610, the target RAS 630 also receives a data packet for the target RAS 630 which is a base station adjacent to the serving RAS 610. The frequency band to be used for transmission, that is, FA is allocated (step 619). That is, the ACR 650 informs the frequency band information to be used by the target RAS 630 through an FA assignment message. In this case, the frequency band allocated to the target RAS 630, that is, FA is allocated differently from the frequency band allocated to the serving RAS 610. That is, the FA allocation for the serving RAS 610 and the target RAS 630 is assigned to different FAs, for example, by assigning 1FA to the serving RAS 610 and 3FA to the target RAS 630, respectively. .

When the target RAS 630 receives the FA assignment message from the ACR 650, the target RAS 630 transmits a FA assignment confirmation message to the ACR 650 in response to the FA assignment message (step 621).

In the above description, a configuration in which the ACR 650 sequentially transmits an FA allocation message transmitted to the serving RAS 610 and the target RAS 630 is described. When the load sharing response message is received, the FA allocation message may be simultaneously transmitted to the serving RAS 610 and the target RAS 630.

Next, when the ACR 650 receives the FA assignment response message for FA allocation from the serving RAS 610 and the target RAS 630, the ACR 650 allocates the serving RAS 610 and the target RAS 630. In step 623, the data packet transmitted to the subscriber station 670 is split according to the allocation information of one FA. Subsequently, the ACR 650 divides the data packet transmitted to the subscriber station 670 using different frequency bands for the serving RAS 610 and the target RAS 630 (steps 625 to 631). step). For example, the ACR 650 transmits a data packet through 1FA through the serving RAS 610 and transmits a data packet through 3FA through the target RAS 630.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

As described above, the present invention enables to perform different scheduling using different FAs in the IEEE 802.16d communication system, thereby not only increasing resource efficiency of RASs, but also improving transmission speed of data packets to subscriber stations. You can. In addition, the load of each RAS for the data packet transmission is also minimized, thereby minimizing the load of the entire system. In addition, as the base station or the FA is not newly added, but a small RAS can be used, such as using existing RASs, system construction cost can be reduced. In addition, the present invention has the advantage that can provide an optimal service to the remote island region or suburban (suburban) area.

Claims (36)

A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighbor RAS, a scheduling method for data packet transmission, comprising: When detecting a load abnormality of the serving RAS serving the subscriber station, dividing the data packet targeting the subscriber station into a first data packet and a second data packet; Allocating the first data packet to the serving RAS, allocating the second data packet to the neighbor RAS, and then scheduling the first data packet to be transmitted to the subscriber station through different frequency bands. . The method of claim 1, The dividing of the data packet into a first data packet and a second data packet may include disposing the first data packet unit and the Nth data packet units included in the data packet so as not to be identical to each other. Said method, characterized in that divided into. The method of claim 1, The controlling of the first data packet to be transmitted to the subscriber station through the serving RAS and the neighbor RAS includes: a resource for transmitting the first data packet in the serving RAS and the second data packet in the neighbor RAS; And differently setting a frequency band of a resource to be transmitted so that the first data packet and the second data packet are transmitted to the subscriber station through different frequency bands. Broadband wireless access including subscriber stations, a plurality of radio access stations (RAS) providing services to the subscriber terminals, and an access control router (ACR) for controlling the RASs. In a communication system, a scheduling method for data packet transmission, If the load of a particular RAS in service to the subscriber stations increases above a predetermined threshold, the data packet targeting the subscriber terminals corresponds to at least one or more adjacent RASs, and the divided data packet is divided into the at least one. And transmitting in different frequency bands through one or more adjacent RASs, respectively. The method of claim 4, wherein And dividing the data packet according to the number of adjacent RASs so that the first to N-th data packet units included in the data packet are not equal. The method of claim 4, wherein The transmitting of the divided data packet to the subscriber station through at least one or more adjacent RASs may include setting different frequency bands of resources for transmitting the data packet in each of the adjacent RASs so that each of the divided data packets is different from each other. And transmitting to the subscriber station through another frequency band. A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighbor RAS, When the serving RAS detects that a problem occurs in the service to the subscriber station, the serving RAS notifies the ACR of its load abnormality; And transmitting the M-th data packet obtained by dividing the data packet targeting the subscriber station to the subscriber station according to the control of the ACR. The method of claim 7, wherein The M-th data packet includes non-identical data packet units among the first to N-th data packet units included in the data packet, and includes the first to N-th data packets included in the data packet. The remaining data packet units other than the data packet units included in the M-th data packet among the packet units are generated as a K-th data packet, and the K-th data packet is transmitted through the neighbor RAS. The method of claim 8, The transmitting of the M-th data packet to the subscriber station may include setting the resource of the M-th data packet to be different from the frequency from which the K-th data packet is transmitted and its frequency. The method characterized in that the transmission to the terminal. A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighbor RAS, Receiving a notification from the ACR to transmit a data packet to the subscriber station; And transmitting, to the subscriber station, a K-th data packet obtained by dividing the data packet targeting the subscriber station according to the control of the ACR. The method of claim 10, The K-th data packet includes non-identical data packet units among the first data packet unit to the N-th data packet unit included in the data packet, and includes the first data packet unit to N-th data included in the data packet. The remaining data packet units other than the data packet units included in the K-th data packet among the packet units are generated as the M-th data packet, and the M-th data packet is transmitted through the serving RAS. The method of claim 11, In the transmitting of the K-th data packet to the subscriber station, a frequency band set such that a resource to which the K-th data packet is transmitted is different from a resource to which the M-th data packet is transmitted is designated by the ACR, And transmitting the K-th data packet to the subscriber station in the designated frequency band. A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighbor RAS, Receiving a first data packet obtained by dividing a data packet dividedly transmitted from the serving RAS and the target RAS and a second data packet excluding the first data packet; And combining the received first data packet and the second data packet to restore the original data packet. The method of claim 13, The first data packet includes non-identical data packet units among the first to N-th data packet units included in the data packet, and the second data packet includes first data included in the data packet. And the remaining data packet units other than the data packet units included in the first data packet among the packet units to the N-th data packet units. The method of claim 14, The frequency of the serving RAS in which the first data packet is received and the frequency of the adjacent RAS in which the second data packet is received are different from each other. A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) to control a neighbor RAS, Receiving a split transmission instruction message of the data packet from the ACR, recognizing the split transmission of the data packet in response to the instruction message, and transmitting a response message corresponding to the instruction message; Subsequently, the first data packet obtained by dividing the data packet targeting the subscriber station is received from the serving RAS according to the control of the ACR, and the first data packet except the first data packet from which the data packet is divided from the adjacent RAS Receiving a second data packet; And combining the received first data packet and the second data packet to restore the original data packet. The method of claim 16, The first data packet includes non-identical data packet units among the first to N-th data packet units included in the data packet, and the second data packet includes first data included in the data packet. And the remaining data packet units other than the data packet units included in the first data packet among the packet units to the N-th data packet units. The method of claim 17, The frequency of the serving RAS in which the first data packet is received and the frequency of the adjacent RAS in which the second data packet is received are different from each other. A subscriber station, a serving radio access station (RAS) that currently provides services to the subscriber station, a neighboring RAS that is different from the serving RAS and capable of providing services to the subscriber station, the serving RAS and the In a broadband wireless access communication system including an access control router (ACR) for controlling a neighbor RAS, The ACR receives the state information transmitted from the serving RAS, and in advance, notifies that the data packet is divided and transmitted to the subscriber station through the serving RAS in response to confirming that the serving RAS is loaded or not according to the state information. Process, The ACR divides a data packet targeting the subscriber station into a first data packet and a second data packet, and uses a frequency to be used for transmitting the first data packet divided in the serving RAS, and a divided packet in the adjacent RAS. Allocating a frequency to be used for transmitting the second data packet; The ACR controlling the first data packet to be transmitted to the subscriber station through the serving RAS and the second data packet to the subscriber station in the allocated frequency band through the adjacent RAS; The serving RAS transmits the first data packet to the subscriber station through a frequency band allocated to the serving RAS. The neighbor RAS transmitting the second data packet to the subscriber station through a frequency band allocated thereto; The subscriber station receives the first data packet through the frequency band used by the serving RAS, receives the second data packet through the frequency band used by the neighboring RAS, and then the first data packet and the first data packet. And combining the data packets to restore the data packets. The method of claim 19, The serving RAS further comprises the step of requesting load distribution to the ACR if it detects that its load is increased. The method of claim 19, The ACR receives status information transmitted from the serving RAS and compares the load of the serving RAS with a threshold according to a system setting; And if the load of the serving RAS is greater than the threshold as a result of the comparison, notifying the subscriber station that the data packet is divided and transmitted. The method of claim 19, When the subscriber station receives a notification from the ACR that a data packet is divided and transmitted, the subscriber station transmits a response corresponding to the notification to the ACR, and the ACR receives a response to the notification from the subscriber station. The method as claimed in claim 1, wherein the serving RAS allocates a frequency differently used for transmitting the first data packet and a frequency used by the neighboring RAS for transmitting the second data packet. The method of claim 19, The ACR receives load information transmitted from the serving RAS, compares the load information of the serving RAS with a predetermined threshold value according to a system setting, and if the load information of the serving RAS is greater than the predetermined threshold value, the data. And dividing a packet and controlling the packet to be transmitted to the subscriber station through a serving RAS and an adjacent RAS. The method of claim 19, The ACR receives load information transmitted from the serving RAS, compares the load information of the serving RAS with a predetermined threshold value according to a system setting, and if the load information of the serving RAS is greater than the predetermined threshold value, the data. And transmitting a packet to the subscriber station through the neighbor RAS. The method of claim 19, The process of dividing the data packet into a first data packet and a second data packet by the ACR may include: forming the first data packet unit and the N-th data packet unit included in the data packet so as not to be identical to each other; And dividing it into two data packets. The method of claim 19, The controlling of the ACR to transmit the first data packet through the serving RAS and the second data packet to the subscriber station through the neighbor RAS may include: a resource for transmitting the first data packet in the serving RAS; And differently setting frequencies of resources for transmitting the second data packet in the adjacent RAS so that the first data packet and the second data packet are transmitted to the subscriber station. A system for transmitting and receiving data packets in a broadband wireless access communication system, When detecting a load abnormality of a serving radio access station (RAS) currently connected to a subscriber station, the data packet targeting the subscriber station is divided into a first data packet and a second data packet, and the first data packet is divided into the first data packet and the first data packet. A data packet and a second data packet are allocated to a serving RAS and a neighboring RAS in different frequency bands so that the first data packet and the second data packet are divided and transmitted to the subscriber station through the serving RAS and the neighboring RAS. Access control router (ACR) to control, Periodically transmits its own state information to the ACR, requests load sharing to the ACR when it detects an abnormal state of its own, and sends the first data packet to the subscriber station at the allocated frequency according to the control of the ACR. The serving RAS to transmit, When the second data packet is transmitted from the ACR to which the data packet targeting the subscriber terminal is divided, transmitting the second data packet to the subscriber terminal at the allocated frequency according to the control of the ACR. With RAS, In response to the control of the ACR, the first data packet is received through a frequency used by the serving RAS, the second data packet is received through a frequency used by the adjacent RAS, and the received first data is received. And the subscriber station for combining the packet and the second data packet to restore the original data packet. The method of claim 27, Wherein the ACR notifies in advance that a data packet is divided and transmitted to the subscriber station when the load of the serving RAS increases. The method of claim 27, The ACR receives load information transmitted from the serving RAS, compares the load information of the serving RAS with a predetermined threshold value according to a system setting, and if the load information of the serving RAS is greater than the predetermined threshold value, the data. And divides a packet and transmits the packet to be transmitted to the subscriber station through a serving RAS and an adjacent RAS. The method of claim 27, The ACR receives load information transmitted from the serving RAS, compares the load information of the serving RAS with a predetermined threshold value according to a system setting, and if the load information of the serving RAS is greater than the predetermined threshold value, the data. And control a packet to be transmitted to the subscriber station through the neighbor RAS. The method of claim 27, The serving RAS, upon performing a service with the subscriber station, detects an increase in its load, and automatically requests load distribution to the ACR. The method of claim 27, And when the subscriber station receives a notification from the ACR that a data packet is to be divided and transmitted, the subscriber station transmits a response corresponding to the notification to the ACR. The method of claim 27, The ACR divides the first data packet unit and the N-th data packet units included in the data packet into the first data packet and the second data packet so as not to be identical. The method of claim 27, The ACR sets a frequency of a resource for transmitting the first data packet in the serving RAS and a resource for transmitting the second data packet in the neighboring RAS to be different from each other. And control the transmission to the subscriber terminal. The method of claim 27, wherein the ACR, A packet divider for dividing the data packet into the first data packet and the second data packet; And an arrangement for controlling the first data packet to be transmitted through a first frequency corresponding to the serving RAS, and controlling the second data packet to be transmitted through a second frequency corresponding to the neighboring RAS. Said system. The method of claim 27, wherein the subscriber station, A FA controller for checking frequency information received through a plurality of receivers according to the control information from the ACR, and determining whether to change a reception frequency band from the serving RAS and the adjacent RAS according to the frequency information; A FA allocation unit for allocating different frequency bands to be received by a plurality of receivers according to frequency bands transmitted by the serving RAS and the neighboring RAS according to the determination information from the FA controller; Receives only the first data packet transmitted from the serving RAS through a frequency band allocated from the FA allocation unit, and receives only the second data packet transmitted from the adjacent RAS through a frequency band allocated from the FA allocation unit. At least one or more receivers, And a packet multiplexer for combining the first data packet and the second data packet received through the receivers to restore the first data packet and the second data packet.

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