KR20110056222A - Method for providing data communication service in multi channel network - Google Patents

Abstract

PURPOSE: A data communication method in a multi channel network is provided to maximize the usage frequency of a multi channel with a high throughput and a transmission delay. CONSTITUTION: If a control phase is created, a Ur is able to begin a channel competition(S400, S402). If a transmission reservation is succeeded while transmitting an RTS(Request To Send), the Ur is able to begin a CTS(Clear To Send) from a receiving terminal(S404). If the transmission reservation succeeds, the Ur is moved to a reserved channel when the C1 is completed(S406). The Ur can begin data transmission(S408). If the transmission reservation fails, the Ur participates a channel competition(S410).

Description

METHOD FOR PROVIDING DATA COMMUNICATION SERVICE IN MULTI CHANNEL NETWORK}

The present invention is to support the quality of service (QoS) of the user in a multi-channel network (multi-channel network), in particular, a communication protocol (Media Access Control, MAC) based communication protocol having a multiple transmission rate, For example, the present invention relates to a data communication method in a multi-channel network suitable for reducing a traffic delay of a real-time service terminal when operating in a multi-hop network in an ad-hoc protocol environment.

The present invention is derived from a study conducted as part of the IT industrial source technology development project of the Ministry of Knowledge Economy and Korea Institute of Industrial Technology Evaluation and Management [2008-F-044-02, Intelligent construction IT convergence to improve electromagnetic wave, sound and building environment New technology development].

The conventional multichannel protocol is divided into two phases, for example, a control phase and a data phase, as shown in FIG. 1, in which one phase, for example, channel 0, is used for the control phase. A control signal containing channel information and packet information is exchanged in the data phase.

Control signals transmitted and received in this control phase are, for example, Request To Send (RTS), Clear To Send (CTS), and Remote Entry Service (RES) signal.

In detail, the transmitting terminal transmits the RTS signal to the receiving terminal after passing through a back-off window based on the IEEE 802.11 Distributed Coordination Function (DCF) mode. In this case, the RTS signal may include channel information of the transmitting terminal and an ID of the receiving terminal.

The receiving terminal analyzes the channel information transmitted from the transmitting terminal, selects the channel with the least reservation, and transmits the CTS signal along with the corresponding information (for example, the reservation information) to the transmitting terminal.

The transmitting terminal receiving the CTS signal transmits the RES signal to the receiving terminal to inform the receiving terminal of the receiving terminal that has not received the CTS signal containing the above-mentioned reservation information.

When such a reservation ends and the control phase ends, all the terminals participating in the contention move to the reserved channel according to the reservation information of the control phase and start data transmission.

In the data phase, both the transmitting terminal and the receiving terminal move to the reserved channel according to the signals transmitted and received in the above-described control phase to start data transmission.

As such, in a multichannel environment, data may be transmitted in the data phase by using information reserved in the control phase.

In the existing technology, since all terminals gathered in one place and competed to avoid collisions, all terminals had to participate in the competition at the same time. That is, all users are given an equal decision without considering individual traffic characteristics of each of the terminals. In addition, the existing scheme is that all the terminals can participate in the competition, while all the terminals are gathered in the control phase, no other channel is used. In other words, waste of frequency resources is severe.

In this way, since the control phase must have a certain length to increase the probability of reservation between the terminals and succeed in data transmission, there is a limit that cannot excessively reduce its size. Therefore, it can be seen that the frequency resource wasted during the contention period between the terminals actually takes a large part. In addition, the real-time service users who are greatly affected by the transmission delay in this process show a transmission failure and have a problem that the quality of service (QoS) is not guaranteed.

Accordingly, in the present invention, when operating as a multi-hop network in a media access control (MAC) based communication protocol having multiple transmission rates, for example, an ad-hoc protocol environment. In order to effectively utilize the wasted frequency resources, and at the same time, considering the characteristics of individual traffic, we intend to provide data communication technology in a multi-channel network that can provide more opportunities for transmission to real-time service users who are sensitive to transmission delays.

According to a data communication method in a multi-channel network for solving the problems of the present invention, in the multi-channel protocol environment in which the control phase is divided into a channel contention section of the real-time service terminal and the channel contention section of the non-real-time service terminal, the real-time The method may include a process in which a service terminal and the non-real time service terminal initiate channel competition, and a process in which the real time service terminal performs channel competition in priority.

Here, in the data communication method, when the real-time service mobile terminal is successfully reserved through the channel competition, when the channel competition section of the real-time service terminal is terminated, the real-time service mobile terminal moves to the reserved channel and transmits data. It may further include a process of initiating.

The real time service terminal may include a source node and a target node.

In addition, the non-real time service terminal may include a source node and a target node.

In addition, the source node may inform the target node of its data type through a Request To Send (RTS) message.

The non-real time service terminal may not perform a channel contention while the real time service terminal performs a channel contention in the channel contention period of the real time service terminal.

According to a data communication method in a multi-channel network for solving the problems of the present invention, the process of starting a channel competition when the control phase occurs to the calling terminal, the step of transmitting the RTS by the calling terminal, When the transmission reservation is successful, the calling terminal receives a clear to send (CTS) from the receiving terminal; and when the transmission reservation is successful during the channel competition period of the calling terminal, the transmission time is terminated. The calling terminal may move to a reserved channel to initiate data transmission.

Here, the originating terminal may include a source node for a real time service.

According to a data communication method in a multi-channel network for solving the problems of the present invention, a plurality of originating terminal and the receiving terminal is a multi-channel channel competition through a control phase divided into a first channel contention period and a second channel contention period A data communication method in a protocol environment, comprising: receiving a CTS by a receiving terminal when an RTS is received by the receiving terminal, and transmitting the CTS from the real-time transmitting terminal after the first channel contention period elapses Determining whether it is received or received from a non-real-time transmitting terminal, if the RTS is received from the real-time transmitting terminal, the receiving terminal moves to a reserved channel to receive data, and the RTS receives the non-real-time If received from a real-time transmitting terminal, the receiving terminal is equal to the end of the second channel contention interval. And moving to the reserved channel at the time of receiving the data.

Here, the first channel contention period may be a channel contention period of a real-time service terminal.

The second channel competition section may be a channel competition section of a non real-time service terminal.

Due to the present invention, when applied to a multi-channel ad-hoc environment, the use of such a multi-channel while having high throughput and low transmission delay, taking advantage of the multi-channel, Can be increased as much as possible. In addition, since the transmission delay is not a big factor for the general data user, it enables the real-time service user to compete first, so as not to exceed the transmission delay limit and to guarantee the quality of service (QoS) of the real-time service user. Can be.

1 is an exemplary diagram of a conventional multichannel protocol;
2 is a diagram illustrating a configuration of a multi-channel network for implementing a data communication method according to an embodiment of the present invention;
3 is an exemplary diagram of a multichannel protocol according to an embodiment of the present invention;
4 is a data communication method in a multi-channel network according to an embodiment of the present invention, which is a flowchart of a data communication process of an originating terminal (real-time service terminal);
5 is a flowchart of a data communication process of a calling terminal (non-real-time service terminal) as a data communication method in a multi-channel network according to an embodiment of the present invention;
6 is a flowchart of a data communication process of a receiving terminal as a data communication method in a multi-channel network according to an embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, and only the embodiments make the disclosure of the present invention complete, and the general knowledge in the art to which the present invention belongs. It is provided to fully inform the person having the scope of the invention, which is defined only by the scope of the claims. Like numbers refer to like elements throughout.

In describing the embodiments of the present invention, if it is determined that a detailed description of a known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the embodiments of the present invention, which may vary according to intentions or customs of users and operators. Therefore, the definition should be based on the contents throughout this specification.

Combinations of each block of the accompanying block diagram and each step of the flowchart may be performed by computer program instructions. These computer program instructions may be mounted on a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment such that instructions executed through the processor of the computer or other programmable data processing equipment may not be included in each block or flowchart of the block diagram. It will create means for performing the functions described in each step. These computer program instructions may be stored in a computer usable or computer readable memory that can be directed to a computer or other programmable data processing equipment to implement functionality in a particular manner, and thus the computer usable or computer readable memory. It is also possible for the instructions stored in to produce an article of manufacture containing instruction means for performing the functions described in each block or flow chart step of the block diagram. Computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operating steps may be performed on the computer or other programmable data processing equipment to create a computer-implemented process to create a computer or other programmable data. Instructions that perform processing equipment may also provide steps for performing the functions described in each block of the block diagram and in each step of the flowchart.

In addition, each block or step may represent a portion of a module, segment or code that includes one or more executable instructions for executing a specified logical function (s). It should also be noted that in some alternative embodiments, the functions noted in the blocks or steps may occur out of order. For example, the two blocks or steps shown in succession may in fact be executed substantially concurrently or the blocks or steps may sometimes be performed in the reverse order, depending on the functionality involved.

Prior to the description of the embodiment, the present invention provides data that can improve the quality of service (QoS) of a user in a multi-channel situation based on the IEEE 802.11 Distributed Coordination Function (DCF) mode in a mobile communication system. The present invention relates to a communication technology, which allows a plurality of terminals to support an efficient quality of service (QoS) by ensuring proper priority in consideration of a user's data type in a plurality of channel environments. Therefore, by providing a service that can increase the service satisfaction of users by reducing the delay and blocking probability of real-time traffic users in a multi-channel environment, it is easy to achieve the purpose of the present invention from this technical idea. Could be.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a diagram illustrating a multi-channel network configuration for implementing a data communication method according to an exemplary embodiment of the present invention, and includes a plurality of mobile nodes, for example, mobile terminals 100 and 200 / for transmitting / receiving control signals and data. 1 to 200/6), and may include a real time service terminal or a non real time service terminal.

In FIG. 2, the mobile terminal 100 may be, for example, a transmitting terminal which is a source node, and may include a controller, a wireless communication unit, and the like.

The mobile terminal 200/1 located within a distance in which the mobile terminal 100 can communicate with each other may be, for example, a receiving terminal that is a target node, and like the mobile terminal 100, a controller, a wireless device. The communication unit may be included.

In addition, assuming that a mobile terminal, for example, reference numeral 200/2 located within a distance in which communication with the mobile terminal 200/1 is a receiving terminal, the mobile terminal 200/1 may be a transmitting terminal. .

As such, what is referred to as a transmitting terminal or a receiving terminal for the mobile terminals 100, 200/1 to 200/6 is merely illustratively illustrated to help understand the technology in describing the embodiments to be described later. It should be noted that the function is not limited. For example, the mobile terminal 200/1 may be represented as a receiving terminal when the mobile terminal 100 is a source node, and may be represented as a transmitting terminal when the mobile terminal 200/2 is a target node. will be.

Such mobile terminals 100, 200/1 to 200/6 may be, for example, CDMA phones, W-CDMA phones, smartphones, laptops, note pads, tablet PCs, and the like. Various multimedia terminals may be applied, and this fact will be readily appreciated by those skilled in the art.

3 is an exemplary diagram of a multichannel protocol for implementing a data communication method in a multichannel network according to an embodiment of the present invention.

As illustrated in FIG. 3, in the multi-channel protocol for implementing a data communication method according to an embodiment of the present invention, a conventional control phase is divided into two sections, for example, a section C1 and a section C2. It features.

In this case, section C1 is a section in which real-time service terminals compete with each other to reserve a channel, and section C2 is a section in which all service terminals (real-time service terminals and non-real-time service terminals) have a channel competition with equal priority. During the channel contention period, the transmitting terminal for transmitting the control signal and data, for example, the mobile terminal 100 may specify its data type through a Request To Send (RTS) message.

Since the present invention should give priority to a real-time service terminal, high priority is given to real-time service terminals, for example, mobile terminals 200/1 to 200/3, and non-real-time service terminals, for example, mobile terminals. Low priority can be given to the fields 200/4 to 200/6.

In section C1, priority is given to mobile terminals 200/1 to 200/3, which are real-time service terminals, and the right to compete first among mobile terminals 200/1 to 200/3, and these mobile terminals ( While 200/1 to 200/3 compete, mobile terminals 200/4 to 204/6, which are non-real time service terminals, do not compete.

As such, when the priority is given to the real-time service mobile terminals 200/1 to 200/3, which are given priority, the data is transferred to the channel according to the information that has been reserved before the end of the designated C1. . During this period, channel competition is still ongoing in the control channel.

In the past, the waste of frequency resources was severe because it was necessary to wait until all the races were terminated in one channel. However, in the exemplary embodiment of the present invention, it is not necessary to wait until the end of the channel races. In the data channel, the non-real-time service terminal starts transmission of the non-real-time service terminal after all of the transmission of the real-time service terminal is completed in the channel as the information of the terminal included in the channel list so that the real-time service terminal can transmit first.

Hereinafter, the above-described configuration will be described in detail with reference to the flowcharts of FIGS. 4 to 6 attached to a data communication method in a multichannel network according to an embodiment of the present invention.

Prior to the description of the embodiments, the real-time service terminal applied to the data communication method of the present invention will be referred to as Ur and the non-real-time service terminal (data service terminal), respectively.

First, FIG. 4 is a flowchart illustrating a data communication process of an originating terminal, in particular, Ur.

As illustrated in FIG. 4, Ur may start channel contention as soon as a control phase occurs without considering other users (S400).

When the channel competition starts, the RTS can be transmitted (S402).

If the transmission reservation succeeds because the RTS is not attempted to be transmitted simultaneously with other terminals, the CTS may be received from the receiving terminal (S404).

If the transmission reservation success time is smaller than the channel contention interval C1 of Ur, that is, if the transmission reservation is successful during the C1 interval, when the C1 ends, the transmission can be moved to the reserved channel in advance (S408). . In this case, when there are many terminals that exist together, data transmission may be started in the transmission reservation order.

If the transmission reservation is unsuccessful during the C1 interval, it may rejoin the channel contention, and if the transmission reservation is successful, data may be transmitted at the start of the data phase (S410).

5 is a flowchart illustrating a data communication process of an originating terminal, particularly Ud.

As shown in Fig. 5, Ud has to wait until the race of Ur is finished because priority is not given. However, if the number of Ur is very small, for example, if the number is less than the preset number, waiting for the final section of C1 may decrease the performance. If you calculate this and think that the period is over, you can start the competition.

That is, in step S500, the length of C1 may be calculated based on information of the previous Ur, and it may be determined whether the current time is greater than C1 (S502).

Since C1 thus determined is only expected, Ur may exist. Therefore, since Ud may change even after Ud participates in the competition, Ud must watch all the reservation information while waiting until all control phases are finished.

When the reserved terminals C2 ends, the reserved terminals may move to the reserved channel to start data transmission (S504). At this time, although the transmission is in the order of reservation, Ur can be given priority even if the reservation is made before Ur.

6 is a flowchart illustrating an example of a data communication process of a receiving terminal.

6 may be operated when the RTS is received by the receiving terminal.

If the receiving terminal RTS is received after the channel information is updated (S600) (S602), the receiving terminal may transmit a CTS to make a reservation (S604).

Thereafter, after C1 has elapsed (S606), the receiving terminal can determine whether the above-described RTS is received from Ur or from Ud.

If the RTS is received from Ur (S608), the receiving terminal may move to the reserved channel immediately and receive data according to the reservation order (S610).

On the other hand, if the RTS is received from the Ud (S612), the receiving terminal waits until the end of all the channel competition, and after the end of C2 may move to the reserved channel and receive the data in order (S614) (S616).

In all of these cases, if the reservation is not established or the transmission is completed, it is also possible to enter a sleep mode until the next control phase starts, thereby minimizing the power consumption.

As described above, according to the present embodiment, a plurality of terminals can support an efficient service quality by ensuring proper priority in consideration of the data type of the user in a plurality of channel environments, and thus, the real-time traffic user It is implemented to improve user's service satisfaction by reducing delay and blocking possibility.

100: source node (sending terminal)
200/1 to 200/3: target node (real time receiving terminal)
200/4 to 200/6: target node (non real-time receiving terminal)

Claims (11)

In a multi-channel protocol environment in which a control phase is divided into a channel contention section of a real-time service terminal and a channel contention section of a non-real-time service terminal, starting the channel contention between the real-time service terminal and the non-real-time service terminal;
Including, by the real-time service terminal, priority channel competition.
Data communication method in a multichannel network.
The method of claim 1,
The data communication method,
If the real-time service mobile terminal is successful in the reservation through the channel competition, when the channel competition section of the real-time service terminal is terminated, the real-time service mobile terminal further comprising the step of starting the data transmission to the reserved channel;
Data communication method in a multichannel network.
The method of claim 1,
The real time service terminal includes a source node and a target node
Data communication method in a multichannel network.
The method of claim 1,
The non-real time service terminal includes a source node and a target node.
Data communication method in a multichannel network.
The method according to claim 3 or 4,
The source node informs the target node of its data type through a Request To Send (RTS) message.
Data communication method in a multichannel network.
The method of claim 1,
In the channel contention period of the real-time service terminal, the non-real-time service terminal does not have a channel contention while the real-time service terminal performs a channel competition.
Data communication method in a multichannel network.
Starting a channel race when a control phase occurs to the calling terminal;
Transmitting, by the calling terminal, the RTS;
Receiving, by the calling terminal, a clear to send (CTS) from the receiving terminal when a transmission reservation of the calling terminal is successful;
If the transmission reservation is successful during the channel contention period of the originating terminal includes the step of starting the data transmission by moving to the reserved channel at the time when the channel contention period of the originating terminal ends;
Data communication method in a multichannel network.
The method of claim 7, wherein
The originating terminal includes a source node for a real-time service
Data communication method in a multichannel network.
A data communication method in a multi-channel protocol environment in which a plurality of originating terminals and receiving terminals perform channel contention through a control phase divided into a first channel contention period and a second channel contention period,
Transmitting, by the receiving terminal, the CTS to the calling terminal when the RTS is received by the receiving terminal;
Determining whether the RTS is received from a real time transmitting terminal or a non-real time transmitting terminal after the first channel contention interval elapses;
If the RTS is received from the real-time transmitting terminal, the receiving terminal moves to a reserved channel to receive data;
If the RTS is received from the non-real-time transmitting terminal, receiving the data by moving to the reserved channel at the same time as the second channel contention period ends.
Data communication method in a multichannel network.
The method of claim 9,
The first channel contention period is a channel contention period of a real time service terminal.
Data communication method in a multichannel network.
The method of claim 9,
The second channel contention period is a channel contention period of a non real-time service terminal.
Data communication method in a multichannel network.

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