KR20080030168A - Data forwarding device and method in multi-wireless mesh network system supporting heterogeneous wireless communication standards - Google Patents

Abstract

A data forwarding apparatus in a multi-radio mesh network system supporting heterogeneous wireless communication standards according to the present invention includes a neighbor buffer in which user data for each neighbor is temporarily stored; A user data processor configured to store the user data in the neighbor buffer in a next-hop unit instead of a wireless link unit when user data to be transmitted through an arbitrary radio link is input; At least one radio link processing unit for requesting dispatching user data after completing transmission of user data stored in its own queue; A neighbor database storing user data transmission scheduling information and available radio link information; And a dispatcher that obtains user data corresponding to the corresponding radio link from a neighbor buffer only after dispatching is requested from the radio link processing unit, and then enqueues it to the corresponding radio link processing unit. In this case, as link state becomes more dynamic than conventional multi-radio transmission, it is possible to efficiently and flexibly select a radio link and forward user data.

Description

Data forwarding apparatus and method in multi radio mesh network system that support radio communication standard more than different kind}

1 is a functional block diagram of an MRTD in a conventional multi-radio mesh network.

2 is a functional block diagram illustrating a configuration of a data forwarding apparatus in a multi-radio mesh network system supporting heterogeneous wireless communication standards according to the present invention.

FIG. 3A is a diagram illustrating an example of creating an NRIB in a Homogeneous node in a data forwarding apparatus in a multi-radio mesh network system supporting heterogeneous wireless communication standards according to FIG. 2; FIG.

FIG. 3B is a diagram illustrating an example of creating an NRIB in a heterogeneous node in a data forwarding apparatus in a multi-wireless mesh network system supporting heterogeneous wireless communication standards according to FIG. 2; FIG.

4 is a flowchart illustrating a data forwarding method in a multi-wireless mesh network system supporting heterogeneous wireless communication standards according to the present invention.

<Explanation of symbols for the main parts of the drawings>

100: neighbor buffer 200: user data processing unit

300: at least one radio link processing unit

400: Neighbor Database 500: Dispatcher

The present invention relates to an apparatus and method for data forwarding in a multi-wireless mesh network system supporting heterogeneous wireless communication standards.

In general, unlike a conventional wired network, a wireless network has many performance limitations due to the characteristics of wireless data communication such as signal interference during data transmission / reception.

In order to overcome these inherent limitations, developments and efforts have been made to maximize the throughput of the network by reducing the interference of signals by using various radio access technologies in a single network.

Such efforts have been further accelerated by the development of radio technology, hardware (H / W) manufacturing technology, and the development of chips supporting multi radios.

Conventional transceivers in the wireless network operate in half-duplex. That is, one transceiver cannot transmit and receive data at the same time, and if one node in the transmit / receive range transmits / receives using the same channel, communication of the other side is caused by signal interference. Will interfere.

Recently, in order to overcome the limitations of wireless communication, a multi-hop mesh network may be configured.

In this case, multi-hop-mesh is a multi-radio communication standard through IEEE 802.11a / b / g, WiMAX technology, and is equipped with multiple hardware interfaces using the same radio communication standard in one node and orthogonal to each other. By increasing the number of channels assigned to each interface, simultaneous transmission / reception is possible without signal interference, increasing throughput of existing multi-hop wireless networks.

In addition, different wireless communication standards may be used to distinguish the user access link and the mesh link.

The wireless mesh network, which is currently being developed, maximizes throughput of a wireless multi-hop backhaul network while minimizing signal interference using the above method.

However, in the conventional multi-hop mesh network, one multi-radio structure is proposed in the Ambient Network Project of WWRF.

The above structure has been proposed for the optimal use of radio resources when the terminal develops in the form that the terminal can connect to multiple access networks using multiple radio technologies. In this architecture, the following three concepts are mentioned to utilize various radio resources.

1) Multi-radio Transmission Diversity (MRTD)

2) Multi-radio Multi-hop (MRMH)

3) Multi-route Transmission Diversity (MRoTD)

Multi-radio access here refers to radio access using uncoupled radio channels in different radio access technologies or in a single radio technology.

In this multi-radio environment, three MRTDs are possible through wireless re-selection rate, parallelism of multiple wireless connections, or duplication of multiple wireless connections for reliable data transmission. .

In the proposed MRTD basic structure, as shown in FIG. 1, periodic and continuous monitoring of radio resource conditions is essential for selecting radio resources for MRTD.

The monitoring result is provided to the access selection unit 1 as feedback, and based on this, the user data to be transmitted by selecting an optimal radio resource is transmitted to the lower layer.

At this time, the data transmitted to the specific radio link of the lower layer is inserted into the queue of the radio link according to the traffic load to be transmitted and waits until it is transmitted.

Thus, if for some reason an error occurs in the selected radio link, user data that must be transmitted until the link returns to normal continues to be queued or dropped. For this reason, the proposed MRTD is too dependent on the time scale used in the report of measurement. That is, it was not very efficient in coping with the radio link situation that changes over time.

The transmission environment using multiple radios is used when a radio link to be used is selected until a status report indicating that the link is in a bad state. There may be several options for measuring the quality of the link here.

Therefore, the present invention is a multi-wireless mesh network that supports heterogeneous wireless communication standards for minimizing loss of user data by switching user data sent for transmission after selecting a link to be used for transmission and switching to another wireless link according to link conditions. An apparatus and method for data forwarding in a system are provided.

According to an aspect of the data forwarding device in a multi-wireless mesh network system supporting heterogeneous or more wireless communication standards according to the present invention for achieving the above object, Neighbor buffer for temporarily storing the user data for each neighbor; A user data processor configured to store the user data in the neighbor buffer in a next-hop unit instead of a wireless link unit when user data to be transmitted through an arbitrary radio link is input; At least one radio link processing unit for requesting dispatching user data after completing transmission of user data stored in its own queue; A neighbor database storing user data transmission scheduling information and available radio link information; And a dispatcher that obtains user data corresponding to the corresponding radio link from a neighbor buffer only after dispatching is requested from the radio link processing unit, and then enqueues it to the corresponding radio link processing unit. ).

According to an aspect of a data forwarding method in a multi-wireless mesh network system supporting heterogeneous wireless communication standards according to the present invention, a neighbor radio information base (NRIB) for managing available radio link information of next-hop is provided. Setting); Buffering, by the user data processor, a neighbor data in a next-hop unit instead of a radio link unit for transmission to any radio link; Determining, by the radio link processor, whether a state of its radio link is normal; If the link state is normal in the step of the radio link processor determining whether the state of the radio link is normal, the radio link processor requesting dispatching to the dispatcher after the transmission of the user data is completed; And when dispatching is requested from the radio link processing unit, enforcing the user data buffered in the next hop unit to the corresponding radio link with reference to a neighbor database. do.

Meanwhile, when the link state is not normal when the radio link processor determines whether the radio link is in a normal state, the radio link processor buffers user data stored in its queue in a neighbor buffer. It comprises the step of.

If the link state is not normal in the step of the radio link processing unit determining whether the state of the radio link is normal, the radio link monitors the link state of the radio link until the link is restored above a certain threshold. The step of not requiring patching to the management unit.

And if the link state is normal in the step of determining whether the state of the radio link is normal, the radio link processor requests dispatching to the dispatcher after the transmission of the user data is completed. Supports heterogeneous wireless communication standards characterized in that the number of frames to be transmitted is determined according to the link state of the radio link processing unit.

Hereinafter, exemplary embodiments of a data forwarding apparatus and method in a multi-wireless mesh network system supporting heterogeneous wireless communication standards according to the present invention will be described in detail with reference to the accompanying drawings. At this time, it will be understood by those of ordinary skill in the art that the system configuration described below is a system cited for the purpose of the present invention and does not limit the present invention to the following system.

2 is a diagram illustrating a configuration of a data forwarding apparatus in a multi-wireless mesh network system supporting heterogeneous or more wireless communication standards according to the present invention, and in the multi-wireless mesh network system supporting heterogeneous or more wireless communication standards according to the present invention. The data forwarding apparatus includes a neighbor buffer 100, a user data processor 200, at least one radio link processor 300, a neighbor database 400, and a manager 500.

The neighbor buffer 100 temporarily stores user data for each neighbor.

When the user data to be transmitted through an arbitrary wireless link is input, the user data processing unit 200 stores the user data in the neighbor buffer 100 in a next-hop unit instead of a wireless link unit.

In addition, the radio link processing unit 300 requests dispatching for requesting user data after completing transmission of user data stored in its queue. When the wireless link processing unit 300 fails to transmit user data, the wireless link processing unit 300 stores the user data enqueued in its queue in the neighbor buffer 100, and when the user data transmission fails, the management unit ( Monitoring itself at 500) does not require the dispatcher 500 to dispatch until the link is restored above a certain threshold.

The neighbor database 400 stores user data transmission scheduling information and available radio link information. At this time, the Neighbor database 400 includes: a Neighbor radio information database in which user data transmission schedule information is stored; And a neighbor selection policy database in which available radio link information is stored.

In addition, the dispatcher 500 refers to the neighbor database 400 to obtain user data corresponding to the radio link from the neighbor buffer 100 only when dispatching is requested from the radio link processing unit 300. After that, it enqueues it to the corresponding radio link processing unit 300.

General functions and detailed operations of the above-described elements will be omitted, and the operations will be described based on operations corresponding to the present invention.

A specific multi-radio routing algorithm must provide information on which neighbor (next-hop) to transmit from the current node to send user data to the destination, and the node must inform neighbor nodes of its available radio access information.

The neighbor database 400 is generated by inputting such neighbor information.

That is, user data transmission scheduling information and available radio link information are stored. At this time, the Neighbor database 400 includes: a Neighbor radio information database in which user data transmission schedule information is stored; And a neighbor selection policy database in which available radio link information is stored. Here, the neighbor database 400 is managed through the node manager 600. That is, the node manager 600 scans the available wireless link and registers the neighbor node in the available list of the neighbor database 400 if it is the same as the available wireless link.

The neighbor database 400 is shown in [Table 1].

TABLE 1

neighbor ID MAC 1 Node 1 (R1, R2) Node 2 (R2, R3) Node 3 (R1, R3) Node 4 (R1, R2, R3) MAC 2 SN 1 SN 2 … SN n … … … … MAC k SN 1 SN 2 … SN n

Here, N (i) means a local neighbor node. (1≤i≤n, i.e. there are n local neighbors and there are k available wireless links)

On the other hand, Figure 3a is a diagram showing the NRIB in the Homogeneous node, each node is a structure having all the radio links.

3B shows an NRIB in a heterogeneous node, in which each node has only a specific radio link.

Therefore, the user data to be transmitted, the management unit 500 obtains routing information through the neighbor database (400).

The user data processor 200 temporarily stores user data in the neighbor buffer 100 for each neighbor. That is, when user data to be transmitted through an arbitrary wireless link is input, the user data processing unit 200 stores the user data in the neighbor buffer 100 in a next-hop unit rather than a wireless link unit.

Meanwhile, the radio link processing unit 300 requests the management unit 500 to dispatch the user data after completing the transmission of the user data stored in its queue.

Then, the management unit 500 stores the user data stored in the next-hop that can be transmitted among the user data stored in the neighbor buffer 100 in a queue of the radio link processing unit 300 that dispatches.

As such, when the user data is temporarily stored in the buffer by dispatching to the management unit 500, the radio link processing unit 300 transmits the user data stored in its queue through the corresponding radio link.

After that, if transmission of the user data fails through its wireless link, the corresponding radio link processing unit 300 is enqueued in its own queue and stores the failed user data in the neighbor buffer 100 again. At this time, the failed radio link processing unit 300 monitors the radio link that fails to transmit user data by itself and does not request the management unit 500 to dispatch user data until the radio link is restored above a certain threshold.

Next, a data forwarding method in a multi-wireless mesh network system supporting heterogeneous or more wireless communication standards according to the present invention having the above configuration will be described with reference to FIG. 4.

First, a neighbor radio information base (NRIB) for managing available radio link information of next-hop is set (S1).

Subsequently, the user data processing unit 200 buffers the user data in the neighbor buffer 100 in the next-hop unit rather than the radio link unit for transmission to any radio link (S2).

Subsequently, the radio link processing unit 300 determines whether the state of its radio link is normal (S3).

Thereafter, if the link state is normal (YES) in the step of the radio link processor 300 determining whether the state of the radio link is normal (YES), after the transmission of the user data is completed by the radio link processor 300 The dispatcher 500 dispatches a dispatch request to the dispatcher 500 (S4).

Subsequently, the management unit 500 en-queues the user data buffered in the next-hop unit to the corresponding radio link with reference to the neighbor database 400 (S5).

On the other hand, if the link state is not normal (NO) in the step of the radio link processing unit 300 determines whether the state of its radio link is normal (NO), the user is stored in the queue of the radio link processing unit 300 The data is buffered again in the neighbor buffer 100 (S6).

Subsequently, if the link state is not normal (NO) in the step of the radio link processing unit 300 determining whether the state of its radio link is normal (NO), the radio link monitors its link state to be above a certain threshold. Dispatching is not requested to the management unit 500 until the link is restored (S7).

Although the present invention has been described in detail only with respect to the specific embodiments described, it will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the present invention, and such modifications and modifications belong to the appended claims. .

As described above, according to the data forwarding apparatus and method in a multi-wireless mesh network system supporting heterogeneous wireless communication standards according to the present invention, as the link state is made more dynamic than the conventional multi-radio transmission, it is efficient and flexible. There is an excellent effect of optimally utilizing a multi-radio environment where a user can select a radio link to forward user data.

Claims (8)

A neighbor buffer in which user data for each neighbor is temporarily stored; A user data processor configured to store the user data in the neighbor buffer in a next-hop unit instead of a wireless link unit when user data to be transmitted through an arbitrary wireless link is input; At least one radio link processing unit for requesting dispatching user data after completing transmission of user data stored in its own queue; A neighbor database storing user data transmission scheduling information and available radio link information; And Only when dispatching is requested from the radio link processor, the user data corresponding to the radio link is obtained from the neighbor buffer by referring to the neighbor database and then enqueued to the radio link processor. Data forwarding device in a multi-wireless mesh network system supporting heterogeneous wireless communication standards including a dispatcher. The method of claim 1, The radio link processing unit, If the user data transmission fails, the data forwarding device in the multi-wireless mesh network system supporting heterogeneous wireless communication standards, characterized in that the user data enqueued in its own queue is stored in a neighbor buffer. . The method of claim 2, The radio link processing unit, If transmission of the user data fails, the management unit monitors itself and does not require dispatching to the management unit until the link is restored above a certain threshold value. Data forwarding device in a network system. The method of claim 1, The neighbor database (Neighbor) database, A neighbor wireless information database storing user data transmission schedule information; And A data forwarding device in a multi-wireless mesh network system supporting heterogeneous wireless communication standards including a neighbor selection policy database storing available radio link information. Establishing a Neighbor Radio Information base (NRIB) that manages available radio link information of the next hop; Buffering, by the user data processor, a neighbor data in a next-hop unit instead of a radio link unit for transmission to any radio link; Determining, by the radio link processor, whether a state of its radio link is normal; If the link state is normal in the step of the radio link processor determining whether the state of the radio link is normal, the radio link processor requesting dispatching to the dispatcher after the transmission of the user data is completed; And When dispatching is requested from the radio link processing unit, the management unit refers to a neighbor database, and includes enqueuing the user data buffered in the next hop unit to the corresponding radio link. A data forwarding method in a multi-radio mesh network system supporting the above wireless communication standard. The method of claim 5, If the link state is not normal in the step of determining whether the state of the radio link is normal, the radio link processor buffers user data stored in its queue in a neighbor buffer. Data forwarding method in a multi-wireless mesh network system supporting heterogeneous wireless communication standards further comprising. The method of claim 6, If the link state is not normal in the step of the radio link processing unit determining whether the state of the radio link is normal, dispatching until the link is restored until the link is restored above a certain threshold by monitoring the link state of the radio link. The data forwarding method in a multi-wireless mesh network system supporting heterogeneous wireless communication standards further comprising the step of not requiring the management unit. The method of claim 5, If the link state is normal in the step of the radio link processing unit determines whether the state of its radio link is normal, the step of requesting dispatching to the dispatcher after the transmission of the user data is completed by the radio link processing unit , A data forwarding method in a multi-radio mesh network system supporting heterogeneous wireless communication standards, characterized in that the number of frames to be transmitted is determined according to the link state of the radio link processor.

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