KR100724911B1 - Method and system for forming and transmitting/receiving neighbor base station information in a communication system - Google Patents

Abstract

The present invention provides a serving base station (Serving BS) to inform neighboring base station (Neighbor BS) information to a mobile station (MS) in a broadband wireless access (BWA) communication system. The present invention relates to a configuration and method for transmitting and receiving neighboring base station information. To this end, the present invention, in a communication system including a serving base station for broadcasting the information of the neighbor base stations to the mobile terminal, in the method for the serving base station to transmit the information of the neighbor base stations, the serving base station is a base station adjacent to itself And searching for information about the searched neighbor base stations and comparing the information size of the collected neighbor base stations with the size of a frame to which the information of the neighbor base stations is to be transmitted, and corresponding to the comparison result. Comprising one or more broadcast messages, including the step of setting a field of the broadcast message corresponding to the information included in the configured broadcast message, and broadcasting the broadcast message set the field.

BWA communication system, broadcast message splitting, neighbor base station information, handoff, MOB_NBR_ADV

Description

TECHNICAL AND SYSTEM FOR FORMING AND TRANSMITTING / RECEIVING NEIGHBOR BASE STATION INFORMATION IN A COMMUNICATION SYSTEM}

1 is a diagram schematically illustrating a cell type configured by BSs supporting different modes of operation in a broadband wireless access communication system according to an embodiment of the present invention.

2 is a diagram schematically illustrating a structure of a MOB_NBR-ADV message in a broadband wireless access communication system according to an embodiment of the present invention.

3 is a diagram illustrating the division of a MOB_NBR-ADV message in a broadband wireless access communication system according to an embodiment of the present invention.

4 is a diagram illustrating an operation of a serving BS for splitting a MOB_NBR-ADV message including neighbor BS information according to an embodiment of the present invention.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication system. In particular, in a broadband wireless access (BWA) communication system, a serving base station (Serving BS) transmits neighbor base station (Neighbor BS) information to a mobile terminal (MS). The present invention relates to a method and system for configuring, transmitting and receiving neighboring base station information to notify a mobile station.

In general, communication systems have been developed mainly for voice services, and are gradually developing as communication systems capable of not only voice but also data services and various multimedia services. However, since the voice-oriented communication system has a relatively small data transmission bandwidth and a high usage fee, the voice-oriented communication system cannot meet the rapidly increasing demand for users. In addition, due to the development of the communication industry and increasing user demand for Internet services, there is an increasing need for a communication system that can efficiently provide Internet services. As a result, a broadband wireless access (BWA) communication system has been introduced to efficiently provide Internet services with broadband enough to meet the increasing demand of users.

The BWA communication system is a communication system for integrating and supporting not only voice but also various data services such as low and high speed data and high definition video. The BWA communication system can access PSTN, PSDN, Internet, IMT-2000 and ATM networks in a mobile or fixed environment based on wireless media using broadband, and is a communication system capable of supporting high-speed channel rates. . The BWA communication system is a broadband wireless subscriber network, broadband mobile access according to the mobility (fixed or mobile) and communication environment (indoor or outdoor) of the subscriber station (SS) (hereinafter referred to as 'SS'), the channel rate It can be classified into a network and a high-speed wireless local area network (LAN).

On the other hand, the wireless access method of the BWA communication system is being standardized by the IEEE 802.16 standardization group of the Institute of Electrical and Electronics Engineers, one of the international standardization bodies, and does not consider the fixed state, that is, mobility of the SS. The IEEE 802.16d standard is being proposed as a standard for providing wireless broadband Internet service for non-SS.

The IEEE 802.16d standard system has a wider bandwidth of data transmission than a wireless technology for conventional voice services, and can perform many data transmissions in a short time. It is possible. In addition, various quality of service (QoS) (hereinafter referred to as 'QoS') is guaranteed so that users can receive different quality services according to the characteristics of the service. The IEEE 802.16d system uses a common channel for all users connected to a base station (BS: hereinafter referred to as 'BS'), and each user uses the channel for each uplink and downlink frame. Since the BS is allocated by the BS, the BS must inform uplink and downlink access information so that each user can divide the channel for each frame. To this end, in the IEEE 802.16d system, channel information is divided into an uplink channel and a downlink channel, information about each channel is defined as a TLV (Type, Length, Value), and the defined information is defined as a downlink channel descriptor (DCD). SS information is transmitted to all users by including them in Downlink Channel Descriptor (hereinafter referred to as 'DCD') and Uplink Channel Descriptor (UCD: Uplink Channel Descriptor, referred to as 'UCD') messages. You will be informed.

In addition, the IEEE 802.16 standardization group is in the process of standardizing 802.16e, which adds mobility to the SS of the IEEE 802.16d communication system. The communication system of the IEEE 802.16e standard can transmit a lot of data in a short time because the data transmission bandwidth is wider than that of the conventional wireless technology, and all users share the channel to efficiently use the channel. It is possible. In addition, QoS is guaranteed so that the user can be provided with different quality services according to the characteristics of the service, and with the support of handoff, the mobility of the mobile terminal (MS) will be guaranteed. do.

In the IEEE 802.16e communication system, in order to support handoff of an MS, a BS performs mobile neighbor advertisement (MOB_NBR-ADV), which includes neighbor BS (Neighbor BS) information to all MSs in its cell. The message 'MOB_NBR-ADV' is called periodically to inform the state information of neighboring cells in advance. That is, when an MS located in a cell moves to an adjacent cell, the MS receives a MOB_NBR-ADV message broadcast from a BS that manages a cell located in advance, that is, a serving BS, such as a network ID and channel characteristics. The BS that manages the neighboring cell to be moved, that is, the neighbor BS (Neighbor BS), has information in advance, so that the IEEE 802.16e communication system can support handoff of the MS.

However, in the IEEE 802.16e communication system, when the serving BS has a large number of neighboring cells or the capability of neighboring cells differs significantly from that of a currently serving cell, the amount of neighbor BS information to be transmitted to the MS increases, so that the serving BS has a higher number of MOB_NBR-ADV. The size increases. In this way, as the amount of neighbor BS information increases, all information cannot be delivered in one frame. Therefore, as the size of the MOB_NBR-ADV message including all neighbor BS information, that is, the neighbor BS information increases, the MOB_NBR- You cannot broadcast an ADV message to the MS in one frame. In particular, in the IEEE 802.16e communication system, the BS cannot transmit a MAC to the MS by fragmenting a MAC (Media Access Control) (MAC) management message.

Accordingly, an object of the present invention is to provide a method and system for constructing a broadcast message for informing a MS of information of a neighbor BS in a BWA communication system.

Another object of the present invention is to provide a method and system capable of transmitting and receiving a broadcast message for notifying information of a neighbor BS to an MS in a BWA communication system.

According to an aspect of the present invention, there is provided a communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the serving base station transmitting information of the neighbor base stations. The base station searches for the base stations adjacent to the base station, and collects the information of the searched neighbor base stations to compare the information size of the collected neighbor base stations and the size of the frame to transmit the information of the neighbor base stations, and corresponds to the comparison result Configuring at least one broadcast message including information of the neighbor base stations, setting a field of the broadcast message according to information included in the configured broadcast message, and broadcasting a broadcast message in which the field is set; Include.
According to another aspect of the present invention, there is provided a communication system including a serving base station that broadcasts information of neighbor base stations to a mobile terminal, wherein the mobile terminal receives the information of the neighbor base stations. The mobile terminal receives the broadcast message transmitted from the serving base station, obtains information of the neighbor base stations included in the received broadcast message, and checks whether the broadcast message is divided according to the obtained information. And receiving a broadcast message transmitted from the serving base station if the broadcast message is divided as a result of the checking.
Another method of the present invention for achieving the above object is, in a communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of transmitting and receiving information of the neighbor base stations, the serving base station itself Search for adjacent base stations, and collect information of the searched neighbor base stations, compare the information size of the collected neighbor base stations with the size of a frame to transmit the information of the neighbor base stations, and then correspond to the neighbor base stations according to the comparison result. Composing one or more broadcast messages including information of the mobile station, setting a field of the broadcast message according to the information included in the broadcast message, and broadcasting the broadcast message in which the field is set; When receiving a broadcast message from the base station, the number After acquiring the information of the neighbor base stations included in one broadcast message and confirming whether the broadcast message is divided according to the obtained information, if the broadcast message is divided as a result of the checking, the broadcast message transmitted from the serving base station is further added. Receiving process.
Another method of the present invention for achieving the above object is, in a communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of the serving base station to configure the information of the neighbor base stations, The serving base station searches for the base stations adjacent to itself, and collects the information of the searched neighbor base stations to compare the information size of the collected neighbor base stations and the size of the frame to transmit the information of the neighbor base stations, and the comparison result And configuring at least one broadcast message including information of the neighbor base stations corresponding to the corresponding information, and setting a field of the broadcast message according to the information included in the configured broadcast message.
A system of the present invention for achieving the object of the present invention, in a communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, in a system for transmitting and receiving information of the neighbor base stations, Search and collect information of the searched neighbor base stations, compare the information size of the collected neighbor base stations with the size of a frame to transmit the information of the neighbor base stations, and include the information of the neighbor base stations according to the comparison result. Configure the at least one broadcast message, set the field of the broadcast message according to the information included in the configured broadcast message, and broadcast the broadcast message from the serving base station and the serving base station, which broadcasts the broadcast message in which the field is set. If received, the received broadcast message The mobile terminal acquiring the information of the neighboring base stations included in the mobile station, checking whether the broadcast message is divided according to the obtained information, and further receiving a broadcast message transmitted from the serving base station if the broadcast message is divided as a result of the checking; It includes.
Another system of the present invention for achieving the object of the present invention is a communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the system for configuring the information of the neighbor base stations, the base station adjacent to itself And compare the size of the collected information of the neighboring base stations with the size of a frame to which the information of the neighboring base stations is transmitted and the information of the neighboring base stations according to the comparison result. And the serving base station for configuring one or more broadcast messages including and setting a field of the broadcast message according to the information included in the configured broadcast message.

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Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, if 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 relates to a hand of a mobile terminal (MS) in a communication system, for example, a broadband wireless access (BWA) communication system. In supporting the off, a base station (BS), which is currently providing a service to the MS, is referred to as a 'BS', that is, a serving BS sends information of a neighbor BS to the MS. A method and system for configuring a broadcast message for notification, for example, a Mobile Neighbor Advertisement (MOB_NBR-ADV), hereinafter referred to as MOB_NBR-ADV, are proposed. In addition, the present invention proposes a method and system for transmitting and receiving the MOB_NBR-ADV message including information of neighbor BSs in a BWA communication system. In addition, in the embodiment of the present invention to be described later, when the size of the information of the neighbor BS transmitted from the serving BS to the MS increases the size of the MOB_NBR-ADV message including the information of the neighbor BS, MOB_NBR- having the large size The present invention proposes a method and system for configuring the MOB_NBR-ADV message so that the ADV message can be fragmented and transmitted to the MS, and transmitting and receiving the MOB_NBR-ADV message. The present invention is applicable to the configuration and transmission and reception of all broadcast messages transmitted and received between the BS and the MS as well as the MOB_NBR-ADV message.
In the following embodiment of the present invention, a communication system, for example, a BWA communication system will be described based on the Institute of Electrical and Electronics Engineers (IEEE) 802. 16e communication system for convenience of description, and the IEEE 802.16e communication The system uses Orthogonal Frequency Division Multiplexing (OFDM) and Orthogonal Frequency Division Multiple Access (OFDMA). It is BWA communication system to use. Since the 802.16e communication system uses an OFDM / OFDMA scheme, high-speed data transmission is possible by transmitting a physical channel signal using a plurality of sub-carriers, and supports a multi-cell structure. It is a communication system supporting MS mobility.

1 is a diagram schematically illustrating a structure of a BWA communication system supporting handoff of an MS moving between cells managed by BSs supporting different operating modes in a BWA communication system according to an embodiment of the present invention. .

Referring to FIG. 1, the BWA communication system includes a multi-cell structure, that is, cell 1 101, cell 2 103, cell 3 105, cell 4 107, cell 5 109, and cell 6 ( 111) and cells 7 (113), which manages the cells (101, 103, 105, 107, 109, 111, 113) and supports different operating modes, and moves between each of the BSs (121, 123, 125, 127, 129, 131, 133) and the cells (101, 103, 105, 107, 109, 111, 113). It includes an MS 150 that can be serviced from. In this case, signal transmission and reception between the MS 150 and the BSs 121, 123, 125, 127, 129, 131, and 133 is performed using an OFDM / OFDMA scheme.

In this case, when the MS 150 moves from the cell 1 101 managed by the BS 1 121 to the cell 2 103 managed by the BS 2 123, the MS 150 provides the current service to the MS 150; That is, the serving BS is changed from BS1 121 to BS2 123, and BS1 121, which is the current serving BS, broadcasts a MOB_NBR-ADV message including BS information of neighbor cells to the MS 150. The MS 150 receiving the MOB_NBR-ADV message has already received the information of the neighbor BSs through the MOB_NBR-ADV message. Proceed to perform the handoff. That is, BS1 121, which is the current serving BS, broadcasts a MOB_NBR-ADV message to the MS 150 moving to Cell 2 103 to inform neighbor BS information, that is, information of BS2 123, in advance. 150) receives the MOB_NBR-ADV message and recognizes BS2 123 information included in the MOB_NBR-ADV message. As a result, the BWA communication system supports handoff of the MS 150.

In the BWA communication system having such a structure, the information of the neighbor BSs is included in the MOB_NBR-ADV message so that the serving BS delivers the information of the neighbor BSs to the MS, and the structure of the MOB_NBR-ADV message is shown in Table 1 below. .

Syntax Size Notes MOB_NBR-ADV_Message_Format () Management Message Type = 49 8 bits Operator ID 24 bits Unique ID assigned to the operator Fragmentation Index 4 bits Current Fragmentation Index Total Fragmentation 4 bits Total number of fragmentation N_NEIGHBORS 8 bits For (j = 0; j <N_NEIGHBORS; j ++) Neighbor BS ID 48 bits PHY Profile ID 32 bits Configuration Change Count 8 bits Incremented each time the information for the associated neighbor BS has changed TLV Encoded Neighbor information Variable TLV specific HMAC Tuple 21 bytes See 11.4.11
As shown in Table 1, the MOB_NBR-ADV message includes a plurality of information elements (IEs), that is, an 8-bit Management Message Type = 49 field indicating a type of a transmitted message. It is allocated for operator identification and used for sharing by a series of BSs. A 24-bit Operator ID field indicating an operator's identifier (ID), an 8-bit N_NEIGHBORS field indicating a number of adjacent BSs, and 21 bits. HMAC Tuple field of, together with information of all neighboring BSs. In addition, the MOB_NBR-ADV message includes a 4-bit Fragmentation Index field and a Total Fragmentation field, each representing a neighbor set of neighbor BSs.

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That is, the neighbor set field of neighbor BSs is divided into one or more divided MOB_NBR-ADV messages transmitted as the index of the MOB_NBR-ADV message transmitted in the current frame. It is divided into a 4-bit Fragmentation Index field indicating the identification number of the message, and a 4-bit Total Fragmentation field indicating how many MOB_NBR-ADV messages have been divided into a total of MOB_NBR-ADV messages. . The form of the MOB_NBR-ADV message including the newly added fragmentation information, that is, the Fragmentation Index field indicating the index of the currently transmitted MOB_NBR-ADV message and the Total Fragmentation field indicating the total number of partitioned MOB_NBR-ADV messages, is shown in FIG. As shown.
2 is a diagram schematically showing the structure of a MOB_NBR-ADV message in a BWA communication system according to an embodiment of the present invention.
Referring to FIG. 2, when the amount of information of neighbor BSs increases, the size of the MOB_NBR-ADV message increases so that the MOB_NBR-ADV message cannot be transmitted to the MS in one frame. After dividing to within the size, the total number of fragmented MOB_NBR-ADV messages, which are fragmentation information of the MOB_NBR-ADV message, is included in the Total Fragmentation field, and the index of the fragmented MOB_NBR-ADV message transmitted in the current frame is fragmented. Send it in the Index field. When there is more than one partitioned MOB_NBR-ADV message, the partitioned MOB_NBR-ADV messages corresponding to the total number of partitioned MOB_NBR-ADV messages are sequentially transmitted to the MS through the corresponding frame. Here, the Fragmentation Index field indicates the indexes of neighboring BSs included in the MOB_NBR-ADV message transmitted in the current frame, so that the MS identifies the divided MOB_NBR-ADV messages and the MOB_NBR-ADV message transmitted in the current frame. Separate. In addition, the Total Fragmentation field indicates the divided total number of MOB_NBR-ADV messages transmitted to the MS, so that the MS determines whether there is a MOB_NBR-ADV message to be transmitted to another frame after the current frame. That is, the MS recognizes how many frames the MOB_NBR-ADV message will be transmitted through the Total Fragmentation field, and accordingly receives all MOB_NBR-ADV messages transmitted in one or more frames to obtain information of all neighboring BSs. .

The N_NEIGHBORS field includes a 48-bit Neighbor BS ID field indicating an identifier of the neighbor BSs, a 32-bit PHY Profile ID field indicating a downlink physical channel frequency of the neighbor BSs, and the MOB_NBR-ADV message. An 8-bit Configuration Change Count field indicating a change count for the UE and a variable-bit TLV Encoded Neighbor information field indicating information associated with the neighbor BSs and indicating information of neighboring BSs encoded with TLV (Type, Length, Value). do.
As such, the BWA communication system according to an embodiment of the present invention may obtain information of neighbor BSs as the MS receives a MOB_NBR-ADV message including the above fields from a serving BS, and obtains information of the neighbor BSs. When the acquired MS moves to another cell, the MS supports the handoff of the MS since the MS has information of the BS that manages the cell to be moved in advance. In addition, the BWA communication system includes a Fragmentation Index field and a Total Fragmentation field, so that if the size of the MOB_NBR-ADV message is large and cannot be transmitted to the MS in one frame, the size of the MOB_NBR-ADV message is limited to one. The MOB_NBR-ADV message can be transmitted to the MS through one or more frames by dividing the frame to be within a frame size. That is, according to the present invention, even if the size of the MOB_NBR-ADV message increases as the amount of information of neighboring BSs increases, the MOB_NBR-ADV message can be divided and transmitted to the MS, and the MS receives the divided MOB_NBR ADV message. By doing so, information of neighbor BSs is obtained in advance.

In the BWA communication system according to another embodiment of the present invention, the structure of the MOB_NBR-ADV message including information of neighbor BSs so that the serving BS delivers information of neighbor BSs to the MS is shown in Table 2 below.

As shown in Table 2, the MOB_NBR-ADV message is used to share a plurality of BSs, i.e., an 8-bit Management Message Type = 49 field indicating a type of a message to be transmitted and received, and to be shared by a series of BSs. A 24-bit Operator ID field indicating an identifier (ID) of the operator, a 8-bit Configuration Change Count field indicating a change count for configuring the MOB_NBR-ADV message, a Co-located FA Indicator bit, and a FA Configuration indicator. Bit, Time / Frequency Synchronization Indicator, BS EIRP Indicator, DCD / UCD Reference Indicator, FA Index Indicator, and FA number are included and includes an 8-bit PHY Profile ID field representing the physical information of the BS.

The size of the MOB_NBR-ADV message of this structure increases as the amount of information of neighbor BSs increases. In this case, when the size of the MOB_NBR-ADV message increases, the MOB_NBR-ADV message cannot be transmitted in one frame, that is, of all neighbor BSs. If the information cannot be transmitted in one frame, the serving BS may divide the size of the MOB_NBR-ADV message to be within the size of the one frame and transmit the divided information to the MS. In addition, when the MOB_NBR-ADV message is split and transmitted to the MS, the MOB_NBR-ADV message to be transmitted should indicate that the MOB_NBR-ADV message has been split, and the MS should receive the MOB_NBR-ADV message indicating that the split has been received. After receiving the frame, all remaining BSs may receive information of all neighboring BSs by receiving all the remaining MOB_NBR-ADV messages.

In order to indicate that the MOB_NBR-ADV message is divided and transmitted, the MOB_NBR-ADV message needs to include the following field. That is, the MOB_NBR-ADV message includes a fragmentation mode field of 1 bit indicating a split mode, a TOT_N_NEIGHBORS field of 7 bits indicating the total number of neighbor BSs, and a split of the MOB_NBR-ADV message when the MOB_NBR-ADV message is split. A 1-bit Start Bit field indicating a start bit and a 6-bit Number of Remaining Fragments indicating the number of MOB_NBR-ADV messages remaining to be transmitted to the next frame after the divided MOB_NBR-ADV message is transmitted in one frame. Contains a field.

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These fields may indicate that the MOB_NBR-ADV message is divided into two types, and the Fragmentation Mode field of the MOB_NBR-ADV message indicates how to indicate the division of the MOB_NBR-ADV message. When the segmentation of the MOB_NBR-ADV message is expressed by the total number of neighbor BSs, that is, the amount of information of neighbor BSs, that is, represented by a TOT_N Neighbors field, the Fragmentation Mode field is set to '1'. In addition, when representing the number of fragments of each divided MOB_NBR-ADV message, the Fragmentation Mode field is set to '0'.

If the Fragmentation Mode field is set to '1', the TOT_N_NEIGHBORS field indicates the total number of neighbor BSs broadcasted by the serving BS, and an 8-bit N_NEIGHBORS field indicates a neighbor BS transmitted through the split MOB_NBR-ADV message. It represents the amount of information of the neighbor BSs as the number of. The MS determines that the number of neighbor BSs transmitted through the N_NEIGHBORS field of the divided MOB_NBR-ADV message, that is, the amount of information of neighbor BSs is greater than the total number of neighbor BSs transmitted through the TOT_N_NEIGHBORS field, and the amount of information of all neighbor BSs. If it is small, since there is information of neighbor BSs not delivered to the MS, the partitioned MOB_NBR-ADV message should be continuously received to obtain information of the remaining neighbor BSs.

On the other hand, when the Fragmentation Mode field is set to '0', since the division of the divided MOB_NBR-ADV messages is necessary, the Start bit field indicates the transmission of the first divided MOB_NBR-ADV message, and the first divided MOB_NBR. When the ADV message is transmitted, the Start bit field is set to '1'. In other words, the Start bit field is set to '0' when the remaining MOB_NBR-ADV message is transmitted. At this time, the Number of REMAINING FRAGMENTS field indicates the number of remaining MOB_NBR-ADV messages to be received by the MS.

In addition, the MOB-NBR-ADV message includes a variable bit TLV Encoded Neighbor information field indicating information related to the neighbor BSs and TLV-coded neighbor BS information, and a downlink channel descriptor for configuring the MOB_NBR-ADV message. DCD: Downlink Channel Descriptor (hereinafter referred to as 'DCD') DCD Configuration Change Count field indicating a change count, and Uplink Channel Descriptor (UCD) for configuring MOB_NBR-ADV message. A UCD Configuration Change Count field indicating a change count, an 8-bit Length field indicating an information length of neighbor BSs included in an N_NEIGHBOR field, a 48-bit Neighbor BS-ID field indicating an identifier of the neighbor BSs, and a preamble 8-bit Preamble Index field indicating the index and 8-bit HO Process Optimization indicating the optimization of the handoff process And a de.

Hereinafter, a method of dividing the size of the MOB_NBR-ADV message including the neighbor BS information to be within the size of one frame by configuring the newly defined MOB_NBR-ADV message will be described.

3 is a diagram illustrating partitioning so that the size of a MOB_NBR-ADV message is within the size of one frame in a BWA communication system according to an embodiment of the present invention.

Referring to FIG. 3, as the number of neighbor BSs increases and the amount of information of the neighbor BSs increases, the size of the conventional MOB_NBR-ADV message 310 increases, so that the size of the conventional MOB_NBR-ADV message 310 increases. The size of one frame 309 is exceeded. As the size of the conventional MOB_NBR-ADV message 310 exceeds the size of one frame 309, the conventional MOB_NBR-ADV message 310 may not be transmitted in one frame 309.

However, as described above, in the present invention, the conventional MOB_NBR-ADV message 310 is divided into a first MOB_NBR-ADV message 320 and a second MOB_NBR-ADV message 330. Here, the conventional MOB_NBR-ADV message 310 includes a Management Message Type field area 301 indicating a message type, an Operator ID field area 303 indicating an operator's identifier, and a neighbor transmitted in one frame 309. An N_NEIGHBORS field indicating the total number of BSs, a field area 305 indicating information of the neighbor BSs, and an HMAC Tuple field area 307 are included. For convenience of explanation, it is assumed that the number of neighbor BSs included in the N_NEIGHBOR field of the conventional MOB_NBR-ADV message 310 is 24. Accordingly, in the field area 305 indicating the N_NEIGHBOR field and information of the neighbor BSs, 24 contiguous BS information is included.

That is, in the present invention, the size of the conventional MOB_NBR-ADV message 310 is divided to be equal to or less than the size of one frame 327, and the divided first MOB_NBR-ADV message 320 is the conventional MOB_NBR-ADV message. A Management Message Type field area 301 indicating a message type included in 310 is included, an Operator ID field area 303 indicating an identifier of an operator, and an HMAC Tuple field area 307.
In addition, the first MOB_NBR-ADV message 320 is an index of the first MOB_NBR-ADV message 320 transmitted in the current frame 327, that is, the divided first MOB_NBR-ADV message 320 and the second MOB_NBR-ADV message ( The MOB_NBR-ADV message transmitted in the current frame 327 among the 330 is a Fragmentation Index field region 321 indicating that the MOB_NBR-ADV message 320 is the first MOB_NBR-ADV message 320, and the first MOB_NBR-ADV message 320 and the second MOB_NBR-ADV The total number of MOB_NBR-ADV messages, in which the conventional MOB_NBR-ADV message 310 is divided as in the message 330, is divided into a first MOB_NBR-ADV message 320 and a second MOB_NBR-ADV message 330 in FIG. Total Fragmentation field area 323 indicating that the MOB_NBR-ADV message divided by 2, N_NEIGHBORS field indicating the number of neighbor BSs included in the first MOB_NBR-ADV message 320 and field area indicating information of the neighbor BSs. 325. Here, it is assumed that the number of adjacent BSs included in the N_NEIGHBORS field of the first MOB_NBR-ADV message 320 is 16 so that the size of the first MOB_NBR-ADV message 320 is within the size of the current frame 327. Accordingly, the N_NEIGHBORS field and the field area 325 indicating information of neighbor BSs include 16 neighbor BS information.
In addition, the second MOB_NBR-ADV message 330 is transmitted to the MS through the current frame 327 and then the first MOB_NBR-ADV message 320 to the MS through the next frame 337. The second MOB_NBR-ADV message 330 includes the same Management Message Type field area 301 as the first MOB_NBR-ADV message 320, an Operator ID field area 303 indicating an identifier of an operator, and an HMAC Tuple field area 307. ). The second MOB_NBR-ADV message 330 is an index of the second MOB_NBR-ADV message 330 transmitted in the next frame 337, that is, among the divided first MOB_NBR-ADV message 320 and the second MOB_NBR-ADV message 330. The MOB_NBR-ADV message transmitted in the next frame 337 includes a fragmentation index field area 331 indicating that it is a second MOB_NBR-ADV message 330.
Like the first MOB_NBR-ADV message 320, the second MOB_NBR-ADV message 330 is the total number of MOB_NBR-ADV messages in which the conventional MOB_NBR-ADV message 310 is divided, and in FIG. 3, the first MOB_NBR-ADV message A total fragmentation field area 333 indicating that the partitioned MOB_NBR-ADV message is 2 and the neighboring BSs included in the second MOB_NBR-ADV message 330 are divided into 320 and a second MOB_NBR-ADV message 330. N_NEIGHBORS field indicating the number and field area 335 indicating the information of the neighbor BSs. The number of neighbor BSs included in the N_NEIGHBORS field of the first MOB_NBR-ADV message 320 is 16 so that the size of the first MOB_NBR-ADV message 320 is within the size of the current frame 327. 16 neighbor BSs are included in the first MOB_NBR-ADV message 320 and transmitted to the MS. As a result, the number of neighbor BSs included in the N_NEIGHBORS field of the second MOB_NBR-ADV message 330 transmitted to the MS through the next frame 337 is transmitted through the first MOB_NBR-ADV message 320 and the remaining 8 The N_NEIGHBORS field and field area 335 indicating information of neighbor BSs includes information of eight neighbor BSs.
In the above description, it is assumed that the size of the first MOB_NBR-ADV message 320 includes information of 16 neighboring BSs so that the size of the first MOB_NBR-ADV message 320 is within the size of the current frame 327. The number of neighbor BSs included in the 1MOB_NBR-ADV message 320 may vary, and the number of neighbor BSs included in the second MOB_NBR-ADV message 330 may also vary. In addition, when the size of the second MOB_NBR-ADV message 330 is larger than the size of the next frame 337, the present invention may use the conventional MOB_NBR-ADV message 310 as three MOB_NBR-ADV messages or more MOB_NBR. The divided MOB_NBR-ADV message is transmitted to the MS through the number of frames corresponding to the number of the divided MOB_NBR-ADV messages.
In this case, the divided MOB_NBR-ADV message includes the respective areas as described above, and when the serving BS divides the MOB_NBR-ADV message, the size of the divided MOB_NBR-ADV message is within the size of one frame. That is, the number of neighbor BSs included in the N_NEIGHBORS field and the field area indicating the information of the neighbor BSs is divided according to the size of one frame. In addition, each divided MOB_NBR-ADV message includes a Management Message Type field area having the same value, an Operator ID field area indicating an identifier of an operator, and an HMAC Tuple field area in common.

The serving BS includes the number of MOB_NBR-ADV messages divided according to the size of the frame to be transmitted to the MS in the Total Fragmentation field, and the index of the divided MOB_NBR-ADV messages transmitted in the current frame is stored in the Fragmentation Index field. After inclusion, the information of neighbor BSs is included in the field area and transmitted to the MS. Accordingly, the serving BS divides the MOB_NBR-ADV message to be within the size of one frame, and then transmits the divided MOB_NBR-ADV message to the MS through the number of frames corresponding to the number of divided MOB_NBR-ADV messages. .

In the above, the case in which the serving BS broadcasts a MOB_NBR ADV message to inform the MS of information of neighbor BSs has been described. Not only the MOB_NBR-ADV message but also the configuration and transmission and reception of a broadcast message transmitted by the serving BS to the MS can be used. Next, an operation of a serving BS for constructing and transmitting a broadcast message including information of neighbor BSs will be described with reference to the accompanying drawings.

4 is a diagram illustrating an operation of a serving BS for constructing and transmitting a broadcast message including information of neighbor BSs according to an embodiment of the present invention.

Referring to FIG. 4, in step 401, the serving BS searches for and collects information of neighbor BSs to be transmitted to the MS, and then proceeds to step 403. In step 403, the collected neighbor BS information and the collected neighbor BS information are compared with the size of a frame to be transmitted to the MS. In this case, when the size of the collected information of the neighboring base stations is smaller than the size of the frame to be transmitted, the serving BS proceeds to step 409, and in step 409, the serving BS includes the information of the neighboring BSs retrieved and collected. After configuring the broadcast message, the configured broadcast message is transmitted to the MS through one frame. The MS receiving the broadcast message through one frame acquires information of neighbor BSs included in the broadcast message, and the BWA system supports handoff of the MS.
On the other hand, if the size of the collected information of the neighbor base stations in step 403 is larger than the size of the transmitted frame, the serving BS proceeds to step 405, the serving BS includes the information of the neighbor BSs in step 405 The broadcast message is divided so as to be within the size of a frame for transmitting the broadcast message.

Then, in step 407, the serving BS sets a field constituting the broadcast message. For example, if the broadcast message including the neighbor BS information is divided into two when the MOB_NBR-ADV message is divided into two in step 405, the Total Fragmentation field of the two divided broadcast messages MOB_NBR-ADV message, that is, divided MOB_NBR- In the Total Fragmentation field of Table 1 representing the total number of ADV messages, a common value of binary value 0010 is set. In addition, the Fragmentation Index field of the first MOB_NBR-ADV message transmitted in the first frame of the divided MOB_NBR-ADV messages, that is, the value of the Fragmentation Index field indicating the index of the first MOB_NBR-ADV message transmitted in the first frame is 0001. The Fragmentation Index value of the second MOB_NBR-ADV message transmitted to the next frame of the first frame, that is, the second frame is set to 0010. Then, in step 409, the serving BS transmits the broadcast message having the field set to the MS through a frame. In this case, when the broadcast message is divided into two in step 405, the serving BS transmits two frames sequentially to the MS.

The broadcast messages divided into one or more are sequentially received through one or more frames such that the size is within the size of the frame to be transmitted. That is, when the received broadcast message is MOB_NBR-ADV mesh ratio, the MOB_NBR-ADV Check the field values of the message. In particular, check the Total Fragmentation field value, which indicates the total number of split MOB_NBR-ADV messages, to check whether the MOB_NBR-ADV message transmitted in the current frame is split.
That is, when the value of the Total Fragmentation field of the transmitted MOB_NBR-ADV message is 0000, it means an unpartitioned MOB_NBR-ADV message. Therefore, the MS receives only one unpartitioned MOB_NBR-ADV message transmitted in the current frame. In this case, the received MOB_NBR-ADV message is decoded to obtain information of the neighbor BS included in the MOB_NBR-ADV message. On the other hand, when the value of the Total Fragmentation field of the MOB_NBR-ADV message transmitted in the current frame is set, the total number of fragmented MOB_NBR-ADV messages is checked through the set Total Fragmentation field value to be transmitted in the subsequent frame. Wait for receipt of the next fragment MOB_NBR-ADV message. That is, the MS receives each of the divided MOB_NBR-ADV messages through one or more frames transmitted sequentially, and also decodes the received MOB_NBR-ADV messages to obtain information of neighboring BSs, and all of the divided MOB_NBRs. By receiving the ADV message, it is possible to obtain all the information of the neighbor base stations broadcast by the neighbor BS station broadcast by the serving BS.

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 the equivalents of the claims.

As described above, according to the present invention, in the WA communication system, a serving BS collects information of neighbor BSs to construct a broadcast message including information of neighbor BSs. By configuring it to be possible, it is possible to send and receive information of many neighboring BS. As a result, the present invention can convey information of many neighbor BSs to the MS to support handoff of the MS when the MS moves to another cell.

Claims (58)

A communication system comprising a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of the serving base station to transmit information of the neighbor base stations, The serving base station searches for neighboring base stations, and compares the information of the searched neighbor base stations with a size of a frame to which the collected information of the neighbor base stations is transmitted; Configuring at least one broadcast message including information of the neighbor base stations according to the comparison result, and setting a field of the broadcast message according to the information included in the configured broadcast message; Transmitting the broadcast message in which the field is set. The method of claim 1, The process of configuring the broadcast message, And dividing the neighbor base stations so that the size of the broadcast message is within the frame size to be transmitted, and including information corresponding to the divided neighbor base stations in the broadcast message. The method of claim 2, The broadcast message, characterized in that the split information of the neighbor base stations and the information of the neighbor base stations included in the broadcast message. The method of claim 3, The splitting information of the neighbor base stations is identification index information of the broadcast message and the total number of information of the broadcast message configured to correspond to the divided neighbor base stations. The method of claim 3, The splitting information of the neighbor base stations is information on the number of neighbor base stations included in the broadcast message and the total number of neighbor base stations searched. The method of claim 3, The broadcast message may include type information of the broadcast message, operator identification information, and configuration information of the broadcast message. The method of claim 3, And the information of the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information of the neighbor base stations, and channel information of the neighbor base stations. The method of claim 1, The setting of the field may include setting corresponding to the total number information of the broadcast message, identification index information of the broadcast message, and information of neighbor base stations included in the broadcast message. The method of claim 8, And the information of the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information of the neighbor base stations, and channel information of the neighbor base stations. The method of claim 8, The setting of the field may include setting corresponding to configuration information of the broadcast message. The method of claim 1, The broadcasting method may include transmitting the broadcast message sequentially by including the broadcast message in a number of frames corresponding to the total number of the configured broadcast messages. A communication system comprising a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of the mobile terminal receiving the information of the neighbor base stations, The mobile terminal receiving a broadcast message delivered from the serving base station; Acquiring information of the neighbor base stations included in the received broadcast message and checking whether the broadcast message is divided according to the obtained information; And receiving the broadcast message transmitted from the serving base station if the broadcast message is divided as a result of the checking. The method of claim 12, The determining of whether the broadcast message is divided may include checking whether the identified neighbor BSs are divided. A communication system comprising a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of the serving base station to transmit information of the neighbor base stations, The serving base station searches for neighboring base stations, and compares the information of the searched neighbor base stations with a size of a frame to which the collected information of the neighbor base stations is transmitted; Configuring one or more broadcast messages including the information of the neighbor base stations according to the comparison result, and setting the fields of the broadcast messages according to the total number information of the configured broadcast messages and identification index information of the broadcast messages; and, Transmitting the broadcast message in which the field is set. A communication system comprising a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of the serving base station configures the information of the neighbor base stations, The serving base station searches for neighboring base stations, and compares the information of the searched neighbor base stations with a size of a frame to which the collected information of the neighbor base stations is transmitted; And configuring at least one broadcast message including information of the neighbor base stations according to the comparison result, and setting a field of the broadcast message according to the information included in the configured broadcast message. Way. The method of claim 15, The process of constructing the broadcast message may include dividing the neighbor base stations such that the size of the broadcast message is within the frame size to be transmitted, and include information corresponding to the divided neighbor base stations in the broadcast message. Configuration method. The method of claim 16, And the broadcast message includes splitting information of the neighbor base stations and information of neighbor base stations included in the broadcast message. The method of claim 17, The splitting information of the neighbor base stations is identification index information of the broadcast message and the total number of information of the broadcast message configured to correspond to the divided neighbor base stations. The method of claim 17, The splitting information of the neighbor base stations is configuration information, characterized in that the information on the number of neighbor base stations included in the broadcast message and the total number of neighbor base stations searched. The method of claim 17, And the broadcast message comprises type information and operator identification information of the broadcast message and configuration information of the broadcast message. The method of claim 17, And the information on the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information on the neighbor base stations, and channel information on the neighbor base stations. The method of claim 15, The setting of the field may include setting corresponding to the total number information of the broadcast message, identification index information of the broadcast message, and information of neighbor base stations included in the broadcast message. The method of claim 22, And the information on the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information on the neighbor base stations, and channel information on the neighbor base stations. The method of claim 22, The setting of the field may include setting corresponding to configuration information of the broadcast message. A communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the method of transmitting and receiving information of the neighbor base stations, The serving base station searches for neighbor base stations adjacent to itself, collects information on the searched neighbor base stations, compares the information size of the collected neighbor base stations with the size of a frame to transmit the information of the neighbor base stations, and then compares the result with the comparison result. Correspondingly configuring at least one broadcast message including information of the neighbor base stations, setting a field of the broadcast message according to the information included in the configured broadcast message, and broadcasting the broadcast message in which the field is set; When the mobile terminal receives a broadcast message from the serving base station, the mobile station acquires information of the neighbor base stations included in the received broadcast message, checks whether the broadcast message is divided according to the obtained information, and then confirms And if the result is a divided broadcast message, receiving the broadcast message transmitted from the serving base station. The method of claim 25, The process of constructing the broadcast message may include dividing the neighbor base stations such that the size of the broadcast message is within the frame size to be transmitted, and include information corresponding to the divided neighbor base stations in the broadcast message. How to send and receive. The method of claim 26, The broadcast message, transmission and reception method comprising the information of the neighboring base stations included in the broadcast message and the split information of the neighbor base stations. The method of claim 27, And the segmentation information of the neighbor base stations is identification index information of the broadcast message and total number information of the broadcast message configured to correspond to the segmented neighbor base stations. The method of claim 27, The splitting information of the neighboring base stations is information on the number of neighboring base stations included in the broadcast message and the total number of neighboring base stations searched information. The method of claim 27, And the broadcast message comprises type information and operator identification information of the broadcast message and configuration information of the broadcast message. The method of claim 27, And the information of the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information of the neighbor base stations, and channel information of the neighbor base stations. The method of claim 25, The setting of the field may include setting corresponding to the total number information of the broadcast message, identification index information of the broadcast message, and information of neighbor base stations included in the broadcast message. 33. The method of claim 32, And the information of the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information of the neighbor base stations, and channel information of the neighbor base stations. 33. The method of claim 32, The setting of the field may include setting corresponding to configuration information of the broadcast message. The method of claim 25, The process of broadcasting the broadcast message, And transmitting the broadcast message sequentially by including the broadcast message in a number of frames corresponding to the total number of the configured broadcast messages. The method of claim 25, The step of checking whether the broadcast message is divided, the method of transmitting and receiving, characterized in that for checking whether the identified neighboring base station information divided. A communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the system for transmitting and receiving information of the neighbor base stations, Search for neighboring base stations adjacent to itself, collect information of the searched neighbor base stations, compare the information size of the collected neighbor base stations with the size of a frame to transmit the information of the neighbor base stations, and correspond to the neighboring result according to the comparison result. The serving base station constituting at least one broadcast message including information of base stations, setting a field of the broadcast message according to the information included in the configured broadcast message, and broadcasting the broadcast message in which the field is set; When the broadcast message is received from the serving base station, information of the neighbor base stations included in the received broadcast message is obtained, and whether or not the broadcast message is divided according to the obtained information, the broadcast is divided as a result of the checking. And the mobile terminal further receiving a broadcast message transmitted from the serving base station if the message. The method of claim 37, The serving base station divides the neighbor base stations so that the size of the broadcast message is within the frame size to be transmitted, and configures the broadcast message by including information corresponding to the divided neighbor base stations in the broadcast message. Transmitting and receiving system characterized in that. The method of claim 38, The broadcast message, transmission and reception system, characterized in that it comprises the information of the neighbor base stations included in the broadcast message and the split information of the base station. The method of claim 39, And the segmentation information of the neighbor base stations is identification index information of the broadcast message and total number information of the broadcast message configured to correspond to the segmented neighbor base stations. The method of claim 39, The splitting information of the neighbor base stations is information on the number of neighboring base stations included in the broadcast message and the total number of neighboring base stations searched, characterized in that. The method of claim 39, And the broadcast message comprises type information and operator identification information of the broadcast message and configuration information of the broadcast message. The method of claim 39, And the information of the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information of the neighbor base stations, and channel information of the neighbor base stations. The method of claim 37, And the serving base station sets a field corresponding to total number information of the broadcast message, identification index information of the broadcast message, and information of neighboring base stations included in the broadcast message. The method of claim 44, And the information of the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information of the neighbor base stations, and channel information of the neighbor base stations. The method of claim 44, The serving base station, the transmission and reception system, characterized in that for setting the field corresponding to the configuration information of the broadcast message. The method of claim 37, The serving base station transmits and receives sequentially, including the broadcast message in a number of frames corresponding to the total number of the configured broadcast message. The method of claim 37, The mobile terminal checks whether the identified neighbor base station information is divided and determines whether the broadcast message is divided. A communication system including a serving base station for broadcasting information of neighbor base stations to a mobile terminal, the system for configuring the information of the neighbor base stations, Search for neighboring base stations adjacent to itself, collect information of the searched neighbor base stations, compare the information size of the collected neighbor base stations with the size of a frame to transmit the information of the neighbor base stations, and correspond to the neighboring result according to the comparison result. And the serving base station for constructing one or more broadcast messages including information of base stations, and setting fields of the broadcast message in accordance with the information included in the constructed broadcast message. The method of claim 49, The serving base station divides the neighbor base stations so that the size of the broadcast message is within the frame size to be transmitted, and configures the broadcast message by including information corresponding to the divided neighbor base stations in the broadcast message. Characterized by a configuration system. 51. The method of claim 50, The broadcast message includes configuration information of the neighbor base stations and information of neighbor base stations included in the broadcast message. The method of claim 51, And the partition information of the neighbor base stations is identification index information of the broadcast message and total number information of the broadcast message configured to correspond to the partitioned neighbor base stations. The method of claim 51, The splitting information of the neighbor base stations is configuration information, characterized in that the information on the number of neighboring base stations included in the broadcast message and the total number of neighboring base stations searched. The method of claim 51, And the broadcast message comprises type information and operator identification information of the broadcast message and configuration information of the broadcast message. The method of claim 51, And the information on the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information on the neighbor base stations, and channel information on the neighbor base stations. The method of claim 49, And the serving base station sets a field corresponding to total number information of the broadcast message, identification index information of the broadcast message, and information of neighbor base stations included in the broadcast message. The method of claim 56, wherein And the information on the neighbor base stations is information on the total number of neighbor base stations included in the broadcast message, identification information on the neighbor base stations, and channel information on the neighbor base stations. The method of claim 56, wherein And the serving base station sets a field corresponding to the configuration information of the broadcast message.

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