KR100643477B1 - Method for acquiring channel-use-time for the purpose of transmitting backward data - Google Patents

Abstract

A method for obtaining a channel use time for transmitting uplink data is provided to guarantee transmission of uplink data by automatically obtaining a channel available time for transmitting the uplink data. The first device is permitted to exclusively use the first channel use time, set for data transmission, by the second device. The first device transmits information about a protocol for using the first channel use time. The first device permits an exclusive use of the second channel use time received from the second device. It is checked whether the second channel use time is a channel use time for uplink data transmission. The first device checks whether the second channel use time to be used by the protocol is a channel use time for uplink data transmission based on the information on the protocol for using the second channel use time received from the second device.

Description

Method for acquiring channel-use-time for the purpose of transmitting backward data}

1 is a view for explaining the superframe structure of the UWB technology.

2 illustrates an example of a layer for obtaining a channel usage time.

3 is a schematic diagram showing an example of a method of acquiring a channel usage time for a conventional data transmission.

4 is a diagram illustrating a frame format of information on a protocol to use channel usage time.

5 is a schematic diagram showing an embodiment of a method for obtaining channel usage time for transmission of reverse data according to the present invention;

The present invention relates to a channel usage time acquisition method for transmitting reverse data. Particularly, the first device transmits predetermined data to a second device, and transmits reverse data such as response data or processing result data according to the transmitted data. The present invention relates to a channel usage time acquisition method for transmitting reverse data for acquiring a channel usage time for receiving reverse data when a first device needs to be transmitted from a second device.

Recently, various technologies have been proposed for a wireless personal area network (WPAN), which allows direct communication between mobile terminals without using separate relay devices such as base stations. have. Representative technologies of WPAN include Bluetooth, Wireless Local Area Network (WLAN), and Ultra Wide Band (UWB).

The UWB is a wireless communication technology using a high frequency band of 2 to 10 GHz. UWB is a technology for exchanging data using microwaves, and its transmission distance is short within 10m, but its transmission speed is fast (100Mbps ~ 1Gbps), and it is attracting attention as a wireless communication technology to realize a home networking system or ubiquitous environment. I am getting it. In addition, since UWB uses a wide frequency band, the power density value can be made very small, and even if it is superimposed on a frequency where other communication signals exist, it hardly interferes.

The wireless communication method between devices having a UWB module uses a time division method in which each device accesses a channel and transmits data at an exclusive channel usage time. In general, as shown in FIG. 1, a wireless communication method between devices having a UWB module uses a fixed time resource called a superframe. The superframe consists of a beacon period and a data transmission period. The beacon period is a period in which each device broadcasts its own beacon frame, and is divided into 256us units called MAS. The data transmission period is a period in which data is transmitted during, for example, A, B, C or D time during the channel usage time obtained by the user.

When a device having a UWB communication module wants to transmit data, two methods are used, namely, a PRI (Prioritized Contention Access) method and a Distributed Reservation Protocol (DRP) method. In the PCA method, each device starts transmission after waiting for an Arbitration Inter Frame Space (AIFS) and a backoff time corresponding to the priority according to the priority of data. However, the PCA method has a problem in that collision occurs when data having the same size AIFS and backoff time exist.

The DRP method is a method of acquiring an exclusive channel usage time by negotiating data to be transmitted by a device in another superframe with other devices. The meaning of acquiring the channel usage time means how many MASs the device to transmit data acquires. At this time, the acquired channel usage time is set to four types: Alien BP, Hard Reservation, Soft Reservation, and Private Reservation. The hard recreation may access a channel only for a device requesting acquisition of a channel usage time. In the soft recreation, the device requesting the acquisition of the channel usage time may access the channel after the AIFS time, and other devices in the network may access the channel after waiting for the AIFS + backoff time. However, there is no provision for how the private recreation is used for the acquired channel usage time.

2 is a diagram illustrating an example of a layer for acquiring channel usage time. As shown, a device having a UWB module is configured with a plurality of layers in order to obtain a channel usage time. The plurality of layers includes a media access control (MAC) 200, a WiMedia MAC Convergence Architecture (WMCA) 210, a protocol adaptation layer (PAL) 220, and a protocol 230.

The MAC 200 defines a method of accessing a channel and a format of a frame in order to transmit and receive data through a wireless communication between a plurality of devices.

The WiMCA 210 is a part providing a common format for using the MAC 200, and is composed of WiDME and WiMUX. The WiDME is in charge of overall control of the device. The WiMUX receives data from the PAL 220 and transmits the data to the MAC 200, or transfers the data received from the MAC 200 to the corresponding PAL 220.

The PAL 220 links the protocol 230 and the WiMCA 210 to use the protocol 230. That is, the protocol 230 provides a service for applying to the WiMCA 210. If the protocol is IP (Internet Protocol), the PAL becomes a WiMedia Network Adaptation Layer (WINET).

The protocol 230 is a communication protocol promised for exchanging data between devices. That is, the connection, disconnection method, communication method, format of data to be sent and received, error detection method, code conversion method, and transmission speed. For example, IP or Internet control message protocol (ICMP). The protocol 230 allows the data received from the application layer to be in a format suitable for the communication standard.

In order to guarantee the quality of service (QoS) in transmitting data over IP, a device having a UWB module acquires a fixed time for transmitting data input from the protocol. This results in no loss of data.

3 is a schematic diagram showing an example of a method of obtaining a channel usage time for a conventional data transmission. In this example, the protocol is IP, and the corresponding PAL is WiNET. As shown, when the WiNET of the first device that wants to acquire the channel usage time is requested to obtain the channel usage time for data transmission from the upper protocol, the first device may specify which portion of the superframe to use exclusively. In operation S300 to S306, a channel usage time for data transmission is obtained in consultation with the device.

After receiving the channel usage time for the data transmission, the first device notifies the WiMCA of the acquired channel usage time to register the information (S308 and S310).

After registering the information on the channel usage time to the WiMCA, the first device transmits information on a protocol to use the obtained channel usage time. The second device receives information on a protocol to use the channel usage time and registers with the WiMCA. The second device transmits a response to the reception of the information on the protocol to use the channel usage time, the first response is received by the first device (S312 to S322).

As a result, the first device may transmit data at the acquired channel usage time.

4 is a diagram illustrating a frame format of information on a protocol to use a channel usage time. As shown, the information of the protocol to use the channel usage time is configured to include a connection-related identifier (400) consisting of two bytes, the upper protocol ID (410) consisting of two bytes, and the like.

In FIG. 3, the first device transmits information on the protocol to use the channel usage time and the second device receives the second device, and the second device transmits a response to the reception in response to the reception (S312). , S314, S320, and S322. The four steps are distinguished by making the value of the connection related identifier 400 different for each step. For example, the connection-related identifier 400 is Connect.Request in step S312, and its value is 0x0001, and in step S314, the value is Connect.indication, and the value is 0x0002, and in step S316, Connect.response. The value is 0x0003, and in step S318, different values are matched for each step, such as Connect.confirm, and the value is 0x0004.

The upper protocol ID 410 is where an ID of a protocol to use a channel usage time is input. That is, since the acquisition of the channel usage time is made by the request of the protocol, the ID of the protocol requesting the acquisition of the channel usage time is input to the ID 410 of the upper protocol.

When the channel usage time acquisition method for transmitting the conventional data is used, transmission of reverse data such as response data indicating the transmission status of the forward data, such as an ack (Acknowledge) frame, is required in Transmission Control Protocol (TCP). In this case, there is a problem in that the transmission of reverse data cannot be guaranteed. That is, when the first device acquires a channel usage time for data transmission, if the type of channel usage time is hard recreation, the second device cannot use the channel usage time. Therefore, in order for the second device to acquire the channel usage time for the transmission of the reverse data, the reverse device cannot transmit the reverse data at an appropriate time due to the requirement of obtaining the channel usage time and waiting.

In addition, if the first device uses soft recreation as the type of channel usage time for data transmission, the second device may acquire the channel usage time by competing with other devices after waiting for AIFS + backoff time. Again, there is a case in which reverse data cannot be transmitted at an appropriate time. As described above, when a channel usage time acquisition method for transmitting backward data is used, when backward data transmission is required, there is a problem in that backward data transmission cannot be guaranteed.

In addition, in the case of using the conventional method for obtaining channel usage time for data transmission, the request for channel usage time for transmission of reverse data is made by the WiNET protocol. Therefore, there is a problem in that when the transmission of reverse data is absolutely necessary, the existing protocol cannot be used as it is.

Therefore, it is an object of the present invention to provide a method for acquiring a channel usage time for transmitting backward data without changing the protocol, that is, when a reverse data is required, the existing protocol can be used as it is.

In addition, another object of the present invention is to acquire the channel usage time for the transmission of the reverse data to ensure the transmission of the data by automatically obtaining the channel usage time for the transmission of the reverse data when the transmission of the reverse data is required To provide a way.

In order to achieve the above object, the channel usage time acquisition method for the reverse data transmission according to the present invention is authorized by the second device for exclusive use of the first channel usage time set by the first device for data transmission. The first device transmits information about the protocol to use the usage time, and permits the exclusive use of the second channel usage time received by the first device from the second device. In addition, it is determined whether the second channel usage time is a channel usage time for transmission of reverse data, and the first device uses the information on a protocol to use the second channel usage time received from the second device. And determining whether the second channel usage time to be used by the protocol is the channel usage time for reverse data transmission.

In addition, according to the present invention, a method for acquiring channel usage time for transmission of reverse data allows a second device to authorize exclusive use of a first channel usage time set by a first device for data transmission, and the second device allows the first device to transmit the data. It is determined whether the protocol requires the transmission of reverse data using information on the protocol to use the first channel usage time received from the device. And the second device is authorized from the first device for exclusive use of the second channel usage time set for the transmission of reverse data, and the second device transmits information on a protocol to use the second channel usage time. It is characterized by.

Hereinafter, with reference to the accompanying drawings will be described in detail a channel usage time acquisition method for the transmission of reverse data of the present invention.

5 is a schematic diagram showing an embodiment of a method for obtaining channel usage time for transmission of reverse data according to the present invention. In this embodiment, the protocol is IP, and the corresponding PAL is WiNET. As shown in the figure, when the WiNET of the first device is required to acquire a channel usage time from a higher level protocol, the channel usage time is obtained by negotiating with the second device which part to exclusively use in the superframe. That is, when the WiNET of the first device is requested to obtain a channel usage time for data transmission from a higher level protocol, the WiNET sets a specific first channel usage time and a type of channel usage time for data transmission. The set first channel usage time and the type of channel usage time are transmitted to the MAC (S500), and the MAC transmits the same.

The MAC of the second device receives the type of the transmitted channel usage time and channel usage time and notifies the WiNET (S502). The WiNET determines whether the notified channel usage time can be used exclusively for data transmission (S504) and responds with a MAC (S506). Whether the channel usage time notified by the WiNET can be used exclusively for data transmission is determined, for example, by being informed from the WiMCA. This is because the WiMCA manages channel usage time that is currently being used for data transmission.

The MAC of the second device transmits the response, and the transmitted response is received by the MAC of the first device and transmitted to the WiNET (S508). If the response is a response indicating that the channel usage time cannot be exclusively used for data transmission, the WiNET of the first device sets a channel usage time different from the channel usage time and transfers it back to the MAC, and acquires the channel usage time. Follow the process to receive.

If the response is that the channel usage time can be used exclusively for data transmission, the WiNET of the first device notifies the WiMCA of the acquired channel usage time to register (S510), and registers the registration result. You are notified (S512).

After receiving the registration result, the WiNET of the first device transmits information on a protocol to use the acquired channel usage time to the MAC (S514). MAC transmits information on a protocol to use the channel usage time. The MAC of the second device receives the information, and the MAC of the second device notifies the WiNET of the received information (S516).

If the WiNET of the second device is informed of the protocol to use the channel usage time, it is determined whether the protocol is a protocol requiring the transmission of reverse data (S518). The WiNET determines whether the same protocol exists by calling a list of protocols that require transmission of reverse data stored in the second device and comparing the informed channel usage time with information about a protocol to be used. If the same protocol exists as a result of the determination, the WiNET of the second device determines that a protocol to use the channel usage time requires reverse data.

After determining whether the protocol to use the channel usage time is a protocol requiring transmission of reverse data, the WiNET of the second device requests the WiMCA to register information on the protocol (S520) and receives the response ( S522).

Then, the WiNET of the second device transmits a response to the reception of the protocol to use the channel usage time to the MAC (S524). The MAC transmits the forwarded response, which is received by the MAC of the first device and forwarded to the WiNET (S526).

In the above process, the first device may transmit data at the acquired channel usage time.

On the other hand, when the WiNET of the second device determines that transmission of reverse data is necessary, the second device obtains a channel usage time by negotiating with the first device what part to exclusively use in the superframe. That is, the WiNET of the second device sets a type of a specific channel use time and a channel use time, and transmits the set channel use time and channel use time to the MAC (S528). The MAC of the second device transmits the type of the channel usage time and the channel usage time, which the MAC of the first device receives. The MAC of the first device transmits the received channel usage time to the WiNET (S530).

The WiNET of the first device determines whether the received channel usage time is a channel usage time that can be used exclusively (S532). The WiNET of the first device should determine whether the channel usage time is a channel usage time for transmitting reverse data (S534). This is because it is not necessary to obtain a channel usage time for reverse data transmission for the reverse data.

The determination is determined by the type of channel usage time received from the second device. That is, when the type of channel usage time received from the second device is private recreation, the first device determines that the channel usage time is a channel usage time for transmission of reverse data. When the type of channel use time is private recreation, it is not prescribed how to use the acquired time. Therefore, if the type of channel usage time received by the WiNET of the first device is private recreation, the channel usage time is recognized as the channel usage time for transmission of reverse data. This prevents the first device from subsequently requesting reverse channel usage time acquisition for reverse data. For example, the determination of whether the requested type of channel usage time is a private recreation is made by analyzing the identifier because there is an identifier that can be distinguished from each other.

A response indicating whether the channel usage time received by the WiNET of the first device can be exclusively used for transmitting reverse data is transmitted to the WiNET of the second device (S536 and S538).

The WiNET of the second device notifies the WiMCA of the time information of the channel usage time for the transmission of the reverse data to be registered (S540), and is notified of the registration result (S542).

After being notified of the registration result, the first device transmits information of a protocol to use the obtained channel usage time. Information on the protocol to use the transmitted channel usage time is notified to the WiNET of the second device (S544 and S546).

When the WiNET of the second device is informed of the protocol to use the channel usage time, it determines whether the channel usage time is for the transmission of reverse data (S548). This is because it is not necessary to obtain a channel usage time for reverse data transmission for the reverse data as described above.

In addition, the determination is determined using a higher protocol ID (ID) in a frame format of information on a protocol using a channel usage time. Since the channel usage time acquisition request for forward data transmission is performed by the WiNET being required to acquire the channel usage time from the upper profile, the protocol to use the channel usage time becomes a protocol requiring the acquisition of the channel usage time. Therefore, the upper protocol ID in the frame format becomes the ID of the protocol requesting the acquisition of the channel usage time. However, the request for acquiring the channel usage time for the transmission of reverse data is not generated by a request of a higher protocol, but is automatically generated by the decision of WiNET. That is, since the channel usage time for the transmission of the reverse data is made by the request of the WiNET, the ID of the upper protocol in the frame format becomes the ID of the WiNET. That is, whether the channel usage time received by the WiNET of the first device is for reverse data transmission is determined by whether the ID of the upper protocol is the ID of the WiNET in the frame format. That is, if the upper protocol ID is the ID of the WiNET in the frame format of the information on the protocol to use the channel usage time, the WiNET of the first device determines that the channel usage time is the channel usage time for transmitting reverse data.

In addition, the determination is determined using a connection-related identifier in the frame format. That is, it is determined whether the connection related identifier is a backward connection identifier in the frame format of the information on the protocol to use the channel usage time. As described with reference to FIG. 4, the connection-related identifier is already set to a unique value in the frame format of the information on the protocol to use the channel usage time. However, only four values are set in the connection-related identifier, so that there is free space that can be defined for the connection other than the forward connection. Therefore, in order to correspond to the forward link of FIG. 4, a reverse link identifier may also be defined for the reverse link. For example, the backward linkage identifier may be set to four, such as Backward Connect.request, Backward Connect.indication, Backward Connect.response, and Backward Connect.confirm, and the reverse linkage identifier may be defined by matching a unique value to the above set. .

If the backward linkage identifier is present in the frame format of the information on the protocol to use the channel usage time received by the WiNET of the first device, the WiNET of the first device indicates that the channel usage time is a channel usage time for transmission of reverse data. To judge.

On the other hand, after the WiNET of the first device determines whether the exclusive use of the channel usage time and whether the channel usage time is for the transmission of reverse data, the information is registered in the WiMCA (S550 and S552). Then, the WiNET of the first device transmits a response indicating that it has received information on a protocol to use the channel usage time, and the second device receives the transmitted response (S554 and S556).

In the above process, the channel usage time for the transmission of reverse data is obtained. After the above process is completed, data communication is wirelessly performed between the first device and the second device.

Meanwhile, the channel usage time for the transmission of the reverse data is related to the size of the MAS for the transmission of the forward data. The size of the MAS of channel usage time for the transmission of reverse data should be smaller than the size of the MAS for transmission of the forward data. This is because the reverse data does not need to transmit a lot of data such as indicating the transmission state of the forward data.

The size of the MAS of the channel usage time for the transmission of the reverse data is defined as a minimum integer equal to or greater than the product of the MAS size of the forward data multiplied by a real number less than one. For example, assuming that the size of the MAS of the channel usage time for forward data transmission is 11, a positive real number less than 1 is a, and a is 0.1, the multiplication of the two is 1.1. In addition, the size of the MAS of the channel usage time for transmitting reverse data becomes 2, which is the minimum integer of 1.1 or more. As a result, the MAS of the channel usage time for the transmission of reverse data is optimized. The value of a is a value that can vary depending on the input.

On the other hand, while the present invention has been shown and described with respect to specific preferred embodiments, various modifications and changes of the present invention without departing from the spirit or field of the invention provided by the claims below It can be easily understood by those skilled in the art.

As described above, the present invention determines whether the protocol requires the transmission of the reverse data by using information on the protocol to use the channel usage time, and when the transmission of the reverse data is necessary, the channel is used for the transmission of the forward data. After acquiring the time, it automatically requests the acquisition of the channel usage time for the transmission of the reverse data. This ensures data transmission when reverse data transmission is necessary.

In addition, the present invention is not required to obtain a channel usage time for the transmission of the reverse data from the upper protocol when the transmission of the reverse data is required. In other words, by determining whether a protocol is required to transmit reverse data by using information on a protocol to use channel usage time, it automatically requests acquisition of channel usage time for reverse data transmission. It is available.

Claims (12)

Acquiring, by the second device, exclusive use of the first channel usage time set by the first device for data transmission; Transmitting, by a first device, information about a protocol to use the first channel usage time; Authorizing, by the first device, exclusive use of the second channel usage time received from the second device; Determining whether the second channel usage time is a channel usage time for transmission of reverse data; And The first device is information on a protocol to use the second channel usage time received from the second device, and the method determines whether the second channel usage time to be used by the protocol is a channel usage time for reverse data transmission. A channel usage time acquisition method for transmission of reverse data. The method of claim 1, And if the first channel usage time cannot be used exclusively, the first device further comprising resetting the channel usage time and transmitting the channel usage time. The method of claim 1, If the second channel usage time cannot be used exclusively, the first device further comprises requesting retransmission of the channel usage time and receiving it from the second device. How to get time. The method according to any one of claims 1 to 3, The determination of whether the second channel usage time is a channel usage time for reverse data transmission is determined by whether the type of the channel usage time is a private reservation. Channel usage time acquisition method for. The method according to any one of claims 1 to 3, The determination of whether the second channel usage time used by the protocol is a channel usage time for reverse data transmission may include determining whether the upper protocol ID is an ID of a PAL in the information on the protocol to use the second channel usage time. A method of acquiring channel usage time for transmission of reverse data characterized by the above-mentioned. The method according to any one of claims 1 to 3, The determination of whether the second channel usage time to be used by the protocol is a channel usage time for reverse data transmission may include determining whether the connection related identifier is a reverse connection identifier in the information on the protocol to use the second channel usage time. A method of acquiring channel usage time for transmission of reverse data characterized by the above-mentioned. Authorizing, by the second device, the exclusive use of the first channel usage time set by the first device for data transmission; Determining, by the second device, whether the protocol requires transmission of reverse data as information on a protocol to use the first channel usage time received from the first device; If the protocol requires the transmission of reverse data, the second device is authorized by the first device for exclusive use of the second channel usage time set for the transmission of reverse data; And And transmitting, by a second device, information on a protocol to use the second channel usage time. The method of claim 7, wherein If the first channel usage time cannot be exclusively used, the second device further comprises requesting retransmission of the channel usage time and receiving it from the first device. How to get time. The method of claim 7, wherein And if the second channel usage time cannot be used exclusively, the second device further comprises resetting the channel usage time and transmitting the channel usage time. The method according to any one of claims 7 to 9, Determining whether the protocol requires transmission of reverse data includes: calling a protocol list requiring transmission of reverse data, comparing the called protocol list with information about a protocol to use the first channel usage time; Method of obtaining a channel usage time for the transmission of reverse data, characterized in that for determining. The method according to any one of claims 1 to 3 and 7 to 9, And wherein the second channel usage time is smaller in size than that of the MAS in the first channel usage time. The method of claim 11, The second channel usage time is a minimum integer time greater than or equal to the value of the MAS multiplied by a real number less than 1 to the size of the MAS of the first channel usage time. .

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