KR100627793B1 - Wireless lan apparatus using tdma/tdd mac protocol and method and system for constructing mac by software upgrade - Google Patents

Abstract

The present invention relates to a WLAN bridge device utilizing a TDMA / TDD MAC protocol and a method and system for implementing MAC using a software upgrade.

The present invention is to configure a wireless relay link using a first wireless LAN bridge (hereinafter referred to as a "master") connected to an IP core network, a plurality of second wireless LAN bridge (hereinafter referred to as "slave") connected to a base station In one embodiment, the master and the slave transmit and receive an RF signal, and perform an orthogonal frequency division multiplexing (OFDM) modem / radio frequency (RF) module for encoding or decoding an RF signal according to a WLAN physical layer standard. ; Process the information of the physical layer decoded by the OFDM modem / RF module to form a medium access control (MAC) frame of a time division multiple access (TDMA) / time division duplex (TDD) scheme, and then transmit to a higher layer or the upper layer A TDMA MAC module configured to convert the TDMA / TDD MAC frame received from the physical layer into information of the physical layer and transmit the information to the OFDM modem / RF module; And a network interface module configured to process data transmitted and received between the IP core network and the master or between the base station and the slave, and to process a response to a ping request and a Simple Network Management Protocol (SNMP) message. Provided is a WLAN bridge device utilizing a MAC protocol of the TDMA / TDD scheme.

According to the present invention, it is possible to provide a higher data rate and stability than the conventional WLAN bridge technology, and there is an effect of smoothly transmitting a large amount of traffic. In addition, it can contribute to improving service quality for wireless Internet users, including public wireless LAN or Wibro, and reducing service provider's network construction cost.

WLAN, Bridge, TDMA, TDD, MAC, Protocol, FPGA, VHDL

Description

Wireless LAN Apparatus Using TDMA / TDD MAC Protocol And Method And System for Constructing MAC by Software Upgrade}

1 is a view showing the structure of a frame of the MAC protocol used by the IEEE 802.11 WLAN,

2 is a diagram illustrating a value of an address field according to a MAC protocol;

3 is a diagram illustrating a medium access method using a CSMA / CA protocol used in a conventional WLAN MAC;

4 is a system configuration diagram of a wireless relay link according to a preferred embodiment of the present invention;

5 is a configuration diagram of a wireless LAN bridge device according to an embodiment of the present invention;

6 is a diagram illustrating a frame structure of a MAC protocol of a TDMA / TDD scheme implemented in a TDMA MAC module according to an embodiment of the present invention;

7 is a system configuration diagram for implementing a TDMA / TDD MAC protocol in a software upgrade method according to an embodiment of the present invention;

8 is a configuration diagram of an FPGA server according to a preferred embodiment of the present invention;

9 is a flowchart illustrating a method for implementing a MAC by a software upgrade method according to a preferred embodiment of the present invention.

<Description of Symbols for Main Parts of Drawings>

400: IP core network 410: master

420: slave 500: network interface module

510: TDMA MAC module 520: OFDM modem / RF module

700: FPGA server 710: host server

712: host CPU 714: host CPU memory

800: FPGA 802: software CPU

804: software system memory 810: Ethernet port

820: flash memory

The present invention relates to a wireless LAN bridge device and a software upgrade (MAC) implementation method using a time division multiple access (TDMA) / time division duplex (MAD) method and a MAC implementation system. will be. More specifically, in order to configure a wireless relay link by applying WLAN technology to a specific point-to-point connection required for high-speed data communication, to guarantee transmission performance superior to that of a bridge technology utilizing the existing WLAN access point technology. A method for implementing a MAC for operating a WLAN bridge and a system by implementing a WLAN bridge device, a software CPU, and a program running on the CPU using the TDMA / TDD MAC technology in the WLAN modem. It is about.

Due to the development of high-speed wired and wireless Internet technology and the proliferation of services, demands for various types of wireless Internet services are increasing. Accordingly, communication service providers are pursuing the development and construction of a wireless communication system that can be cheaper and transmit a large amount of data. Representative examples are Ev-Do system in synchronous mobile phone system and HSDPA (High Speed Downlink Packet Access) technology in asynchronous mobile phone system. In addition, IP-based transmission technologies such as portable Internet and public wireless LAN have been developed and commercialized. Most of these technologies use end-to-end connection as a wireless technology for the convenience of wireless. Accordingly, there is a need for network connection equipment that supports a radio interface with a user terminal such as a base station or an access point (AP).

Equipments such as base stations and access points require access to wired communication networks, such as mobile phone core networks or IP core networks, and must be distributed and deployed to secure service coverage. Therefore, in order to provide a wireless Internet service, it is necessary to install a relay link connecting a wired communication network with a base station or access point that is distributed and installed. Most mobile phone systems provide services that guarantee reliability and stability by installing dedicated lines, but high installation costs and operating, maintenance, and maintenance costs are emerging as problems. As a technology to replace this, wireless bridge technology, which has relatively low reliability and stability in data transmission but has low construction and operation cost, has emerged. In fact, most services except voice calls require a lower level of transmission reliability and stability than data transmission reliability and stability on leased lines, and thus, commercialization of bridge technology using low-cost wireless LANs has been achieved as relay links.

1 is a diagram illustrating a frame structure of a MAC protocol used by an IEEE 802.11 WLAN.

Referring to FIG. 1, a typical MAC protocol includes a frame control field including type or fragmentation information for a corresponding frame, and association identifier (AID) information in the power saving mode. In other cases, the Duration / ID field, the four address fields, the sequence control field, the frame body field, and the cyclic redundancy check (CRC) have different duration values according to each frame type. Contains a field.

The four address fields are shown in the Basic Service Set Identifier (BSSID), Destination Address (DA), Source Address (SA), Receiver Address (RA), and Frame Control fields. In combination with ToDS and FromDS, it has a value as shown in FIG. 2.

FIG. 2 is a diagram illustrating the value of an address field according to the MAC protocol, and the reason for having the structure as shown in FIG. This is to support Carrier Sense Multiple Access / Collision Avoidance.

Although the structure of the conventional MAC protocol improves reliability in data communication between a fixed base station and a mobile mobile terminal, four addresses in the MAC protocol are required for data communication between a fixed base station and a base station, which do not require an ad hoc mode or a power saving mode. Fields or fields such as Duration / ID will only act as a load. Therefore, the conventional MAC protocol structure is inadequate for data communication of a fixed base station using an efficient TDMA scheme.

3 is a diagram illustrating a medium access method using a CSMA / CA protocol used in a conventional WLAN MAC.

In case of transmitting data from Node 1 (Source) to Node 2 (Destination), Node 1 first detects whether the medium is in use and initiates a transmission procedure by sending an RTS frame when not in use. The RTS frame stops propagation of other nodes that wish to use the medium along with reserving the medium for transmission. Receiving the RTS, Node 2 responds with a CTS. Like the RTS frame, the CTS frame prevents other nodes from accessing the medium.

NAV (Network Allocation Vector) performs a function of detecting a carrier on a medium and informs time information when a radio link is reserved.

Data is transmitted between Node 1 and Node 2 that have reserved a medium, and Node 2 receiving the data transmits an acknowledgment (ACK) as a positive response.

This competitive CSMA / CA protocol has the advantage of being simple to implement, but when used in a wireless relay link consisting of a fixed base station or access point, the transmission efficiency of the data is reduced due to contention due to contention.

On the other hand, WLAN bridge equipment requires the development of a physical layer modem chip required for wireless communication and a MAC layer chip or board that reassembles, processes and hands over the physical layer information received from the physical layer to a higher layer. . In general, physical layer modem chips are implemented through ASIC chips or FPGAs because they require precise synchronization settings and fast hardware processing. The MAC layer is developed in the form of physical layers and one-chip ASICs. Implemented through VHDL coding on the FPGA.

However, the above development method has some problems.

First, in the development stage, the configuration or algorithm for MAC implementation is frequently changed. However, if it is written in VHDL, it takes a lot of unnecessary time to compile the code and put the image on the FPGA board. Therefore, when development is required in a short time, there is a difficulty in shortening development time.

Second, debugging should be done for error correction or function verification during development. However, when developing with an FPGA board, there is a disadvantage that debugging or error detection is more difficult than that of the existing upper language.

Finally, FPGA board development is highly hardware dependent compared to higher level languages like C, and languages like VHDL are also very inconvenient for beginners to access.

In order to solve this problem, the present invention, in the configuration of a wireless relay link by applying a wireless LAN technology for a specific point-to-point connection required in high-speed data communication, the transmission is superior to the bridge technology utilizing the existing wireless LAN access point A method for implementing a MAC required for the operation of a WLAN bridge by implementing a WLAN bridge device and a software CPU and a program running on the CPU using a TDMA / TDD MAC technology to guarantee the performance of the WLAN modem. And to provide the system.

According to a first object of the present invention, a first WLAN bridge (hereinafter referred to as a "master") connected to an IP core network and a plurality of second WLAN bridges (hereinafter referred to as "slaves") connected to a base station are used. In configuring a wireless relay link, the master and the slave, orthogonal frequency division multiplexing (OFDM) modem for transmitting and receiving RF signals and encoding or decoding the RF signals according to the WLAN physical layer standard. RF (Radio Frequency) module; Process the information of the physical layer decoded by the OFDM modem / RF module to form a medium access control (MAC) frame of a time division multiple access (TDMA) / time division duplex (TDD) scheme, and then transmit to a higher layer or the upper layer A TDMA MAC module configured to convert the TDMA / TDD MAC frame received from the physical layer into information of the physical layer and transmit the information to the OFDM modem / RF module; And a network interface module configured to process data transmitted and received between the IP core network and the master or between the base station and the slave, and to process a response to a ping request and a Simple Network Management Protocol (SNMP) message. Provided is a WLAN bridge device utilizing a MAC protocol of the TDMA / TDD scheme.

According to a second object of the present invention, an FPGA server having a field programmable gate array (FPGA), a flash memory and an Ethernet port, a host server having a host CPU and a host CPU memory, and a time division multiple access (TDMA) medium (MAC) A method of implementing a MAC by a software upgrade method in a system including an Access Control module, the method comprising: (a) the FPGA of the FPGA server is written and compiled in a Very High Speed Integrated Circuit Hardware Description Language (VHDL); Generating a software CPU and a software system memory by executing the CPU code and the system memory code; (b) storing an embedded operating system and MAC code written in a programming language supported by the embedded operating system in the flash memory of the FPGA server; (c) the software CPU reading data from the embedded operating system and the MAC code to generate data for implementing a TDMA / TDD (Time Division Duplex) MAC protocol; (d) transmitting the data to the TDMA MAC module via the host server; And (e) implementing the TDMA / TDD MAC protocol using the data in the TDMA MAC module.

According to a third object of the present invention, in a system for implementing a medium access control (MAC) through a software upgrade method, a software CPU and software implemented in a VHDL (Very High Speed Integrated Circuit Hardware Description Language) FPGA that uses system memory to execute MAC code written in a programming language supported by the Embedded OS to generate data for implementing the Time Division Multiple Access (TDMA) / Time Division Duplex (TDD) type MAC protocol (Field Programmable Gate Array) server; A TDMA MAC module configured to receive the data generated by the FPGA server and implement a TDMA / TDD MAC protocol; And a host server having a host CPU and a host CPU memory, which mediates communication between the FPGA server and the TDMA MAC module and is responsible for managing the system including processing of Simple Network Management Protocol (SNMP) messages. It provides a software upgrade system MAC implementation system.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

4 is a system configuration diagram of a wireless relay link according to a preferred embodiment of the present invention.

As shown in FIG. 4, a system of a wireless relay link is connected to an IP core network 400, a first WLAN bridge (hereinafter referred to as a “master”) 410 connected to an IP core network 400, and a base station. A plurality of second wireless LAN bridges (hereinafter, referred to as slaves) 420 and mobile communication terminals 430 are configured.

The IP core network 400 provides a data communication service when there is a request for data communication from the mobile communication terminal 430.

Mobile communication terminal 430 is a terminal capable of data communication using a wireless relay link, PDA (Personal Digital Assistant), cellular phone, PCS (Personal Communication Service) phone, GSM (Global System for Mobile) phone, W-CDMA (Wideband CDMA) phones, CDMA-2000 phones, Mobile Broadband System (MBS) phones, notebook computers, and the like.

The master 410 is connected to the IP core network 400 and allocates a band to the slave 420 to access the IP core network 400 according to the data request of the mobile communication terminal 430, and the requested data Download to the slave 420.

When there is a request for data from the mobile communication terminal 430 to the IP core network 400, the slave 420 may request bandwidth request information from the master 410 to access the IP core network 400 through a wireless relay link. Transmits and uploads data in the band allocated from the master 410.

The communication between the master and the slave in the wireless relay link is performed by the MAC protocol of the TDMA / TDD scheme. The configuration and protocol structure of the master and the slave for this purpose will be described later.

4 is for conceptual description of the present invention, the configuration of the wireless relay link system can be used in the wireless LAN or future portable Internet. When used for the WLAN service, the WLAN bridge devices 410 and 420 are implemented as access points. When used for the portable Internet, the master 410 is an access control router (ACR) and the slave 420 is a RAS (Radio Access). Station), and the mobile communication terminal additionally includes a function for receiving a wireless LAN service or a portable Internet service.

5 is a diagram showing the configuration of a wireless LAN bridge device (410, 420) according to a preferred embodiment of the present invention.

The WLAN bridge devices 410 and 420 include a network interface module 500, a TDMA MAC module 510, and an OFDM modem / RF module 520.

The OFDM modem / RF module 520 transmits and receives RF signals and performs encoding or decoding of the RF signals according to the WLAN physical layer standard.

The physical layer of a wireless LAN has a physical layer convergence procedure (PLCP) that connects a MAC and a wireless transmission frame and a physical medium dependency that propagates all bits received from the PLCP to the air using an antenna. It is divided into two sublayers (PMD: Physical Medium Dependent).

An OFDM modem is an IEEE 802.11a standard and uses an orthogonal frequency division multiplexing (OFDM) scheme as a wireless transmission technology. The OFDM method is a method of encoding and transmitting one radio signal to a plurality of subcarriers orthogonal to each other to improve transmission speed per bandwidth and prevent multipath interference.

The TDMA MAC module 510 processes the information of the physical layer decoded by the OFDM modem / RF module 500 to form a TDMA / TDD MAC frame, and then transmits the information to a higher layer or a MAC of the TDMA / TDD method down from the upper layer. The frame is made into the information of the physical layer and transmits to the OFDM modem / RF module 500.

The network interface module processes data transmitted and received between the IP core network and the master or between the base station and the slave, and performs a function such as a response to a ping request or a simple network management protocol (SNMP) message. Ping is a command to check the connectivity of a specified IP address communication device. It is used to check whether a target device is running or a communication network is connected. The communication protocol uses the Internet Control Message Protocol (ICMP). SNMP is a network management protocol of TCP / IP developed based on the Simple Gateway Management Protocol (SGMP) of TCP / IP. It is used to send network management information of network devices such as routers and hubs to the network management system.

6 is a diagram illustrating a frame structure of a MAC protocol of a TDMA / TDD scheme implemented in a TDMA MAC module according to an embodiment of the present invention.

As shown in FIG. 6, the frame of the TDMA / TDD MAC protocol includes a map (MAP) field, a downlink field, an uplink field, and a slave MAC message (hereinafter, referred to as 'SMM') field. It consists of.

The map field is a section for broadcasting map information including band allocation information from the master 410 to the slave 420. The map information includes the following information.

Source Address (SA) and Destination Address (DA)

-Sequence number of map information to prevent duplicate reception of map information

Field type information for identification of a map field, a downlink field, an uplink field, a ranging, and an SMM field

-Length of each field

Master time information for synchronization between master and slave

-Specific slave command information consisting of address and command code for a specific slave

-Band allocation information in the uplink field for each slave

Information about the start time of the SMM field

-ACK information about upload data for each slave

The specific slave command information means information such as changing an operating frequency of a specific slave or temporarily stopping the operation.

In addition, the ACK information about the upload data for each slave is transmitted in a downlink field to be described later, but the reason included in the map field is that the slave transmits upload data in a previous reception frame but has no data to download in the current frame. This is to transmit in the map field because ACK information cannot be received.

The downlink field is a section for broadcasting the download data from the master 410 to the slave 420. The download data includes the following information.

Source and destination addresses

Order number of the downlink field to prevent duplicate reception;

Field type information for identification of a map field, a downlink field, an uplink field, a ranging, and an SMM field

-ACK information about upload data for each slave

The uplink field is a section in which the slave 420 transmits upload data to the master 410 in a band allocated by the master 410. The upload data includes the following information.

Source and destination addresses

-Sequence number of uplink field to prevent duplicate reception

Field type information for identification of a map field, a downlink field, an uplink field, a ranging, and an SMM field

-ACK information about the data downloaded from the master in the downlink field

-Bandwidth request information in the next frame

When there is data to be uploaded in the next frame, the slave 420 uploading data in the current frame transmits the bandwidth request information in the upload data of the current frame. The slave 420 newly accessing the wireless relay network transmits bandwidth request information in an SMM field to be described later.

The SMM field is a section in which the SMM is transmitted from the slave to the master. The SMM includes the following information.

Source and destination addresses

-Sequence number of the SMM field to prevent duplicate reception of the SMM;

Field type information for field identification

-Slave time information for synchronization between master and slave

-ACK information about data downloaded from master

-Band request information of newly entered slave in wireless relay network

If the ACK for the data downloaded from the master 410 is transmitted in the above-mentioned uplink field, but the downloaded slave cannot upload the data in the current frame because the slave does not require the bandwidth in the previous uplink field. Since ACK information cannot be transmitted, ACK information is transmitted in the SMM field.

In Figure 6, there is a transmission gap between each field (Transmission GAP), the reason is that the transmission of the modem itself generated in the process of inputting and erasing the relevant parameters in the register to wirelessly transmit data in the WLAN modem This is due to delay time and preamble transmission time. In addition, in order to transmit both the downlink and the uplink to one modem, it is necessary to switch to the respective state, and the transmission delay time also occurs.

Hereinafter, an operation according to the MAC protocol of the TDMA / TDD scheme described above will be described.

First, when the master 410 broadcasts the map information to all the slaves 420 in the map field section, the slave decodes the map field every frame to provide band allocation information in the uplink field and start time information of the SMM field. Get

When the downlink field period is reached, the master 410 broadcasts download data to all slaves 420, and each slave 420 receives only data coming to itself through a destination address.

When the uplink field period is reached, the slave 420 transmits data to be uploaded in the band allocated from the master 410, band request information for the next frame, and ACK information for the download data to the master.

When the SMM field period is reached, the slave 420 transmits the SMM to the master 410. In this period, slaves newly entering the wireless relay network transmit band request information.

At this time, the SMM uses either a completely competitive or slotted-competitive method between slaves. The slotted-competition method is a method of dividing the SMM transmission interval into several and designating an interval to transmit the SMM for each slave and competing among the slaves within the interval.

The reason why the SMM transmission method is not the TDMA method as described above is because when the new slave participates in the wireless relay network, the master cannot know the new slave in advance and thus cannot allocate the TDMA interval. This is to minimize the SMM transmission interval because the SMM interval is long when the interval is allocated and the entire data transmission interval is reduced.

In addition, the master may variably allocate the lengths of the uplink field, the downlink field, and the SMM field of the MAC frame according to the number of slaves participating in the wireless relay network and the data transmission requirements.

7 is a system configuration diagram for implementing a TDMA / TDD MAC protocol by a software upgrade method according to a preferred embodiment of the present invention.

The system for implementing the TDMA / TDD MAC protocol in a software upgrade method includes an FPGA server 700, a host server 710, and a TDMA MAC module 510.

The FPGA server 700 is written in a programming language supported by an embedded operating system using a software CPU and software system memory implemented in a field programmable gate array (FPGA) in a Very High Speed Integrated Circuit Hardware Description Language (VHDL). It executes the MAC code to generate data for implementing the TDMA / TDD MAC protocol. Here, VHDL is a language for logic design technology of hardware. It is a language developed based on Ada and is suitable for simulation, design, and verification of device specifications.

The host server 710 has a host CPU 712 and a host CPU memory 714 to serve as an intermediary for communication between the FPGA server 700 and the TDMA MAC module 510 and to process SNMP messages. It is in charge of overall system management.

The host CPU 712 transmits the embedded operating system and the MAC code stored in the flash memory 820 in the FPGA server 700 to be described later. The host CPU memory is processed by the host CPU. Save the current data or command code. In this case, the transmission of the embedded operating system and the MAC code may use a general transmission protocol such as a Trivial File Transfer Protocol (TFTP).

The TDMA MAC module 510 receives the data generated by the FPGA server and performs the function of implementing the TDMA / TDD MAC protocol by using the data. Specific functions are as described above.

8 is a diagram illustrating a configuration of an FPGA server according to a preferred embodiment of the present invention.

The FPGA server 700 includes an FPGA 800, an Ethernet port 810 for communicating with a host server 710, and a flash memory 820.

The flash memory 820 stores a MAC code for implementing a TDMA / TDD MAC protocol written in an embedded operating system and a programming language supported by the embedded operating system. The embedded operating system can be an open operating system, embedded Linux or uC / OS-II, and the MAC code can be written in C.

An FPGA is a programmable non-memory semiconductor. In the present invention, a software CPU 802 and a software system memory 804 are configured by creating and compiling a CPU and system memory code in VHDL in the FPGA 800.

The software CPU 802 operates the embedded operating system when the embedded operating system and the MAC code stored in the flash memory 820 are transferred to the FPGA 800 by the host CPU 712, and executes the TDMA / TDD while executing the MAC code under the embedded operating system. It performs the function of generating data for implementing the MAC protocol.

The software system memory 804 temporarily stores data or instruction codes processed by the software CPU 802.

9 is a flowchart illustrating a method for implementing a MAC by a software upgrade method according to a preferred embodiment of the present invention.

The CPU 800 and the system memory code are written and compiled with the VHDL in the FPGA 800, and the compiled CPU code and the system memory code are executed while the FPGA 800 is driven to execute the software CPU 802 and the software system memory 804. It is generated (S900).

The flash memory 820 of the FPGA server stores the embedded OS and the MAC code written in a language supported by the embedded OS (S910).

When the FPGA server 700 is constructed in this way, the host CPU 712 is booted and transmits an embedded operating system and MAC code stored in the flash memory 820 to the FPGA 800 through TFTP (S920) and the FPGA 800. The software CPU 802 is booted to operate the embedded operating system, and executes the MAC code on the embedded operating system to generate data for implementing the TDMA / TDD MAC protocol (S930).

The generated data is transmitted to the TDMA MAC module 510 through the host server 710 (S940), and the TDMA MAC module uses the data to implement the TDMA / TDD MAC protocol (S950).

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

As described above, according to the present invention, it is possible to provide a higher data rate and stability than the existing WLAN bridge technology, and there is an effect of smoothly transmitting a large amount of traffic. In addition, it can contribute to improving service quality for wireless Internet users, including public wireless LAN or Wibro, and reducing service provider's network construction cost.

In addition, by implementing MAC as a software upgrade method, it facilitates debugging, structural changes, and functional tests occurring during development. In general, the MAC layer or other higher layers are used in a higher-level language such as C. Because it implements, it can be implemented more easily and faster than implementing the function in hardware language such as VHDL, and there is an advantage that can be implemented by referring to various libraries or open source codes. Through this, it is possible to contribute a lot to the development of special purpose wireless communication equipment which requires mass production of small parts or wireless communication equipment that needs rapid development.

Claims (18)

In configuring a wireless relay link using a first WLAN bridge (hereinafter referred to as a master) connected to an IP core network and a plurality of second WLAN bridges (hereinafter referred to as a slave) connected to a base station, The master and the slave are each, An orthogonal frequency division multiplexing (OFDM) modem / radio frequency (RF) module for transmitting and receiving an RF signal and encoding or decoding the RF signal according to a WLAN physical layer standard; Process the information of the physical layer decoded by the OFDM modem / RF module to form a medium access control (MAC) frame of a time division multiple access (TDMA) / time division duplex (TDD) scheme, and then transmit to a higher layer or the upper layer A TDMA MAC module configured to convert the TDMA / TDD MAC frame received from the physical layer into information of the physical layer and transmit the information to the OFDM modem / RF module; And A network interface module that processes data transmitted and received between the IP core network and the master or between the base station and the slave, and processes a response to a ping request and a Simple Network Management Protocol (SNMP) message. WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, comprising a. The method of claim 1, The MAC frame of the TDMA / TDD scheme implemented by the TDMA MAC module, A map (MAP) field which is a section for broadcasting map information including band allocation information from the master to a plurality of the slaves; A downlink field which is a period for broadcasting download data from the master to the slave; An uplink field which is an interval for transmitting upload data in a band allocated by the master from the slave to the master; And SMM field which is a period for transmitting a slave MAC message (hereinafter, referred to as 'SMM') including bandwidth request information from the slave to the master WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, comprising a. The method of claim 2, wherein the map information, A source address (SA) and a destination address (DA); A sequence number of the map information for preventing duplicate reception of the map information; Field type information for identification of the map field, the downlink field, the uplink field, ranging, and the SMM field; The length of each field; Master time information for synchronization between the master and the slave; Specific slave command information including an address and a command code for a specific slave; Band allocation information in the uplink field for each slave; Information about a start time of the SMM field; And ACK information on the upload data for each slave WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, comprising a. The method of claim 3, wherein The specific slave command information includes a WLAN protocol device using a TDMA / TDD MAC protocol, characterized in that the information on the operation frequency change or temporary stop of the operation for the specific slave. The method of claim 2, The download data transmitted in the downlink field, Source address and destination address; Sequence number of the downlink field to prevent duplicate reception; Field type information for identification of the map field, the downlink field, the uplink field, ranging, and the SMM field; And ACK information on the upload data for each slave WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, comprising a. The method of claim 2, The upload data transmitted in the uplink field is, Source address and destination address; Sequence number of the uplink field to prevent duplicate reception; Field type information for identification of the map field, the downlink field, the uplink field, ranging, and the SMM field; ACK information about data downloaded from the master; And Bandwidth Request Information in Next Frame WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, comprising a. The method according to claim 5 or 6, When the upload data or the download data is divided into packets and transmitted, the upload data or the download data is The length of the divided packet; Identification information for reassembling the divided packet; Offset information of the divided packet; And Information indicating whether this is the last packet WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, characterized in that it further comprises. The method of claim 2, wherein the SMM transmitted in the SMM field, Source address and destination address; A sequence number of the SMM field for preventing duplicate reception of the SMM; Field type information for field identification; Slave time information for synchronization between the master and the slave; ACK information about data downloaded from the master; And Band request information of the slave newly entering the wireless relay network WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, comprising a. The method of claim 2, The master allocates lengths of the uplink field, the downlink field, and the SMM field according to the number of slaves participating in the wireless relay network and the data transmission requirements, using the MAC protocol of the TDMA / TDD scheme. WLAN bridge device. The method of claim 2, The SMM transmission of the SMM in the SMM field is a WLAN bridge device using the MAC protocol of the TDMA / TDD scheme, characterized in that by any one of a method of completely competing all the slaves or a slotted-competition scheme. In a system that includes a field programmable gate array (FPGA), an FPGA server with flash memory and an Ethernet port, a host server with a host CPU and host CPU memory, and a time division multiple access (TDMA) medium access control (MAC) module. In a method of implementing a MAC by a software upgrade method, (a) generating a software CPU and a software system memory by executing the compiled CPU code and system memory code in the FPGA of the FPGA server in a VHDL (Very High Speed Integrated Circuit Hardware Description Language); (b) storing an embedded operating system and MAC code written in a programming language supported by the embedded operating system in the flash memory of the FPGA server; (c) the software CPU reading data from the embedded operating system and the MAC code to generate data for implementing a TDMA / TDD (Time Division Duplex) MAC protocol; (d) transmitting the data to the TDMA MAC module via the host server; And (e) implementing the TDMA / TDD MAC protocol using the data in the TDMA MAC module; MAC upgrade method of the software upgrade method comprising a. The method of claim 11, wherein step (c) (c1) when the host CPU is booted, transmitting the embedded operating system and the MAC code stored in the flash memory to the FPGA; And (c2) operating the embedded operating system while booting the software CPU of the FPGA, and generating data for implementing the TDMA / TDD MAC protocol by executing the MAC code on the embedded operating system; MAC upgrade method of the software upgrade method comprising a. In a system for implementing a medium access control (MAC) through a software upgrade method, Using the software CPU and software system memory implemented in Very High Speed Integrated Circuit Hardware Description Language (VHDL), MAC code written in a programming language supported by the Embedded OS can be used to execute Time Division Multiple Access (TDMA) / A field programmable gate array (FPGA) server for generating data for implementing a time division duplex (TDD) type MAC protocol; A TDMA MAC module configured to receive the data generated by the FPGA server and implement a TDMA / TDD MAC protocol; And A host server having a host CPU and a host CPU memory, which is responsible for mediating communication between the FPGA server and the TDMA MAC module and for managing the system including processing of Simple Network Management Protocol (SNMP) messages. Software upgrade method MAC implementation system comprising a. The method of claim 13, wherein the FPGA server, An FPGA having the software CPU and the software system memory implemented with the VHDL; A flash memory storing the MAC code written in a programming language supported by the embedded operating system and the embedded operating system; And Ethernet port for communication with the host server Software upgrade method MAC implementation system comprising a. The method of claim 13, wherein the host CPU, And a software upgrade method of controlling the MAC to transmit the embedded operating system and the MAC code stored in the flash memory to the FPGA. The method of claim 15, The system of claim 1, wherein the transfer is performed through a Trivial File Transfer Protocol (TFTP). The method according to any one of claims 13 to 15, The embedded operating system is a software upgrade type MAC implementation system, characterized in that any one of embedded Linux or uC / OS-II as an open operating system. 15. The method according to claim 13 or 14, wherein when the embedded operating system and the MAC code are transmitted from the host CPU to the FPGA, the software CPU first operates the embedded operating system, and executes the MAC code on the embedded operating system. And generating the data for implementing the TDMA / TDD MAC protocol.

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