KR20080011150A - How to Form an Energy-Efficient Multi-hop Multi-radio Mobile Ad Hoc Network Based on Application Needs - Google Patents

Abstract

The present invention relates to a network formation method based on application needs in a multi-hop multi-radio mobile ad hoc network environment. The present invention relates to a radio of a path to be transmitted using a soft-state multi-hop signaling protocol. The network is configured through priority-based decisions in order to set up interfaces and handle conflicting application needs. Multi-hop signaling protocols send and receive control messages over low-power radio interfaces, and use stateful, state-update, and state-removal operations to activate only those interfaces that are needed among the radio interfaces of devices in the multi-hop path and do not need them. Deactivating the interface creates an energy efficient network. In the state setting step, the priority-based state determination and the reverse state setting through the request acknowledgment message are used to solve the problem of different application needs colliding in the multi-hop network.

Description

A Method for Energy-Efficient Multi-Hop Multi-Radio Mobile Ad Hoc Network Formation Based on Application Demands

The present invention relates to a network formation method in a multi-hop multi-radio mobile ad hoc environment. More particularly, the present invention relates to a method for transmitting a network based on a request of an application in a multi-hop multi-radio mobile ad hoc environment. The present invention relates to a method that can save energy of mobile devices by forming.

In the ubiquitous computing environment, mobile devices with multiple radio characteristics easily form spontaneous networks as needed and perform applications with various needs. Mobile devices have a feature that is sensitive to energy consumption, in particular wireless communication over a network interface is a big part of the energy consumption. In this situation, an effective way to save energy in mobile wireless devices while satisfying the needs of the application is to form a network based on the needs of the application.

When a multi-radio device has a radio interface having a low power low transmission performance and a radio interface having a high power high transmission performance, if a small data transmission is desired in an application, a network is formed with only a low power interface. You can use the interface to form a network.

One system that attempted this method was the PAN-on-Demand presented by Michigan University. 'PAN-on-Demand' adopts a method of setting an appropriate network interface or selecting an energy-saving mode according to its characteristics before sending data to members of a personal area network (PAN). The proposed method has the effect of saving energy for the devices configuring the PAN, but it is not applicable to multi-hop mobile ad hoc networks only for networks of single hop distance.

In addition, there are routing methods that support multi-hop multi-radio ad hoc networks. There are multiple radio routing methods of 'DSR' in 'CMU', 'MR-LQSR' in 'Microsoft Research' and 'AODV-MR' in 'Queensland Research Laboratory', but they are optimal for all node pairs in the network. It only provides routing to provide throughput, and has limitations that do not reflect the needs of a particular application or solve energy saving problems.

Accordingly, there is a need for a method for network formation based on application requirements in a multi-hop multi-radio mobile ad hoc environment in view of such constraints by the prior art.

The present invention has been made in view of the above, and an object thereof is to provide a method for forming an energy-efficient network based on application requirements in a multi-hop multi-radio mobile ad hoc network.

One aspect of the present invention for achieving the above object, in forming a multi-hop multi-radio network based on the needs of the application, (a) a control plane (control plane) for transmitting control messages (data plane) for data transmission classifying a network by a data plane; (b) a method of setting a state for forming a network by performing a soft-state multi-hop signaling protocol through a control region.

In this case, the method (a) comprises: (a1) a part of allowing a node to send and receive a control message when data transmission is required while always activating a low power radio interface shared by all nodes; (a2) It includes the part that configures data area by activating necessary network interface according to application needs.

(b) The method comprises: (b1) the sender using the application's request to set up a state for network formation to the route devices from the sender to the receiver; (b2) periodically transmitting and repeating a request at the sender to update a state set in each device; (b3) the step of releasing the setting of the state when the desired work is done in the application or when it is no longer necessary to maintain the setting of the state.

At this time, in step (b1), the sender sends a transmission request including the request of the application along the path found through the routing of the control area to the receiver, the receiver checks the request of the arriving application and sets its own state. It sends back a request acknowledgment message back to the sender that contains the application's request, allowing the intermediate nodes to set their state to meet the application's needs.

In step (b2), the sender operates an update timer for this, in which the sender periodically retransmits a request message for data transmission in progress so as to update the status of the devices. In addition, each node releases the state if it does not receive a request for setting the state for a certain period of time. The update timer runs on the sender's device starting from the first time the request is sent until the end of the data transfer, and the release timer runs from the point where all nodes receive the state setting message and stops running with the state release after a specified time. If the status setting message is received in the meantime, the timer is reset and operated again.

In step (b2), the update timer can make the control load larger but shorten the connection as the cycle gets shorter.The longer the cycle, the smaller the control load is, but the connection is broken more frequently.

In order to provide a quick release with stable sustaining of the state in step (b2), it is preferable that the release timer has a value approximately twice that of the update timer.

In step (b3), the release timer is operated in consideration of the case in which the intermediate node moves away from the path or the sender node moves and is no longer used as the path. A method of explicitly requesting the release of a state after completing all necessary data transmissions at the sender device is included.

Another aspect of the present invention for achieving the above object is a solution to the problem of conflicting needs of different applications in the process of forming a network based on the needs of the application, in the state setting process performed when the request of the application ( c) setting the state in the reverse direction from the receiver to the sender; (d) comparing the needs of the application and determining the status based on priorities in setting the status at each device; (e) This includes how to deal with problems that arise when one device is unconfigured when one device is using the network to meet the needs of another device.

In this case, (c) method takes only the decision work by comparing with the status of the intermediate node in the process of sending the request message considering the conflict situation that may occur in the middle when the request message for setting the status is transmitted from the sender to the receiver. Finally, it operates in the reverse direction with the request of the application arriving when the request is delivered to the receiver node.

And (d) is a method in which each device compares and determines a given request with its own state based on priorities created between the requests of the application. The higher the value of the state it has, the higher the demands of the application are replaced. Therefore, the application's request is finally determined at the moment the request message arrives at the receiver node.

Also, the method (e) requires that a device with a high priority application needs to be used while a device having a low priority application needs to share the settings of a device with a high priority application when a collision occurs. As a method of processing when the setting is released, when the setting is released from the sender's point of view and the update timer expires, a status update message is transmitted, so that the broken network can be recovered.

As described above, according to the present invention, it is possible to activate and use only a radio interface necessary to meet the needs of an application in a multi-hop multi-radio mobile ad hoc network environment, thereby increasing energy efficiency of mobile devices.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the following embodiments are provided to those skilled in the art to fully understand the present invention, and may be modified in various forms, and the scope of the present invention is limited to the embodiments described below. It doesn't happen.

1 is a block diagram illustrating a method for forming a multi-hop multi-radio mobile ad hoc network according to a preferred embodiment of the present invention. The network formation method according to the preferred embodiment of the present invention operates between a user application and a link layer of various radio technologies, and largely includes an application demand manager, a control plane, and a data plane. And mobile ad hoc network routing (MANET routing).

The application request manager 101 transmits the network establishment signal through the control area 102 with the request of the application received from the user application, and processes it in response. The application request manager 101 may instruct transmission to the control region 102 or the data region 103 as needed, which is the lowest power, low performance interface among the radio interfaces present in the link layer. It is connected to and works. In FIG. 1, the control region 102 is shown to operate in connection with MAC A. Packet transmission in the control region 102 is via conventional mobile ad hoc network routing 104. Well-known mobile ad hoc network routing methods include AODV, DSDV, and DSR. After the setting for network formation is completed in the control area 102, the data area 103 is operated by activating a necessary radio interface. Depending on the needs of the application, the data region 103 may be connected to various radio interfaces of the link layer, and it is shown in FIG. 1 that it is connected to the MAC B and operates. Packet transmission in the data area is not simply using mobile ad hoc network routing 104, but rather using static routing through the path made through the setting of the control area 102. Since the path search and the necessary interface settings have already been made in the operation of the control area 102, the transmission of the data area 103 does not incur additional routing load.

FIG. 2 is a signal flow diagram illustrating a procedure in which the multi-hop multi-radio mobile ad hoc network forming method illustrated in FIG. 1 operates, and a message format is defined for each arrow.

When a user application of a sender node requests data transmission to a receiver node with a specific request, the application request manager 102 generates a request message SEND_REQ, which takes a request of the corresponding application, and sends it to the receiver node. There are two kinds of requests of the application used in the present embodiment, 'HIGH_THPUT', which is a request for an application that wants a high throughput, and 'LOW_THPUT', which is a request for an application that wants a low throughput. When there are two radio interfaces MAC A and MAC B, 'HIGH_THPUT' may be connected to MAC B and 'LOW_THPUT' to MAC A. The priority of 'HIGH_THPUT' and 'LOW_THPUT' is assumed to be higher than 'HIGH_THPUT'.

The request message goes through the intermediate nodes and checks whether the request of the application is in conflict, and changes the request of the application, which is the argument value, to the next node. When the request message finally arrives at the receiver node, the receiver node activates its network interface according to the request of the arrived application, and composes and sends a request response message (SEND_REQ_ACK). The request response message (SEND_REQ_ACK) also contains the request of the application as a factor, and the network configuration of the intermediate nodes is made as the response message is forwarded backward to the sender.

When the request response message returns to the sender node, the sender node sends the actual data through the data area 103. The data area transfers data through the radio interface to suit the needs of the application. In the middle of transmitting data, the sender node periodically sends a request update message (REFRESH_REQUEST) according to the operation of the update timer. The content of this message is the same as the request message originally received from the application, and is a message required to continuously update the network formation state in a soft-state manner. The operation of the request update message (REFRESH_REQUEST) is the same as the request message (SEND_REQ), and the intermediate node and the receiver node that received the request initialize their release timer so that the state setting is not released.

When the data transfer is complete, the sender node sends a transmission termination message (FIN_NOTI). This message explicitly instructs the nodes to release their state, causing all received nodes to unconfigure to form a network.

3 is a diagram illustrating an example of a problem in which application requirements collide in a process of forming a network of multi-hop multi-radio. If there are nodes as shown in FIG. 3 and node 1 first requests data transmission of 'HIGH_THPUT' to node 6, nodes 3, 4, and 5, which are intermediate nodes, will form a network using MAC B. After that, when node 2 sends a request of 'LOW_THPUT' to node 7, the request collides with the 'HIGH_THPUT' request from node 3, which is an intermediate node, and it is changed to 'HIGH_THPUT' according to the priority and continues to be delivered. As a result, the request message arriving at the receiver node returns a request response message (SEND_REQ_ACK) at the request of 'HIGH_THPUT', and a network from node 2 to node 7 also uses MAC B. In this situation, if the application of node 1 completes data transmission, the network settings of nodes 3, 4, and 5 are canceled in the termination process, and at the moment, node 2, which is transmitting data via nodes 3, 4, and 5, is transmitted. You won't be able to. However, in Node 2, since the update timer for its request is running, when the next request update message is transmitted, the network can be formed as its original request, 'LOW_THPUT', and the transmission continues.

This method of the present invention has the effect of improving the energy efficiency of the entire mobile node by forming only a network by activating only the interface required by the needs of the application. In addition, if the definition of the application request and the definition of the priority is added, the method may reflect various other needs in the network, and the type of radio interface may also be extended by adding.

1 is a block diagram illustrating a method for forming a multi-hop multi-radio mobile ad hoc network according to an embodiment of the present invention;

2 is a signal flow diagram illustrating a process of operating a method while a sender and a receiver exchange control messages based on the configuration of FIG. 1;

FIG. 3 is a diagram for describing a solution to a problem in which an application demand collides during a network formation process.

Claims (12)

What is claimed is: 1. A method for forming an energy efficient network based on application needs in a multi-hop multi-radio mobile ad hoc network, (a) a method of classifying a network into a control plane for transmitting a control message and a data plane for transmitting data; and (b) performing a soft-state multi-hop signaling protocol through the control region to set a state for network formation. The method of claim 1, wherein the method (a) (a1) a part of allowing a control message to be transmitted and received when data transmission is required while always activating a low power radio interface shared by all nodes; (a2) A method comprising constituting a data area by activating a required network interface according to the needs of an application. The method of claim 1, wherein (b) (b1) the sender using the application's request to establish a state for network formation to the route devices from the sender to the receiver; (b2) periodically transmitting and repeating a request at the sender to update a state set in each device; (b3) releasing the setting of the state when the desired work is done in the application or when it is no longer necessary to maintain the setting of the state. The method of claim 3, wherein in step (b1), The sender sends a send request containing the request of the application to the receiver along the path found through the routing of the control area, the receiver checks the request of the arriving application, sets its status, and then includes the request of the application to the sender. Returning a request acknowledgment message in the reverse direction so that intermediate nodes can set their state to suit the needs of the application. The method of claim 3, wherein in step (b2), The sender is forced to run an update timer for this, allowing the sender to periodically resend the request message for the ongoing data transfer to update the status of the devices. In addition, each node releases the state if it does not receive a request for setting the state for a certain period of time. The update timer runs on the sender's device starting from the first time the request is sent until the end of the data transfer, and the release timer runs from the point where all nodes receive the state setting message and stops running with the state release after a specified time. If the status setting message is received in the meantime, the method of initializing the timer and operating again. The method of claim 3, wherein in step (b2), The update timer is characterized in that the shorter the period, the greater the control load but the less disconnected, and the longer the period, the smaller the control load but the more frequent the connection. The method of claim 3, wherein in step (b2), Wherein the release timer has a value approximately twice that of the update timer to provide fast release with stable persistence of the state. The method of claim 3, wherein in step (b3), Considering the case where the intermediate node moves away from the path or the sender node moves and is no longer used as the path, the release timer is activated to release its state after a certain time and the data required by the sender device. And a method of explicitly requesting release of the state after all transmissions are completed. As a solution to the problem of conflicting needs of different applications in the process of forming a network based on the needs of the application, in the state setting process performed when the demand of the application is given, (c) setting the state in the reverse direction from the receiver to the sender; (d) comparing the needs of the application and determining the status based on priorities in setting the status at each device; (e) a method for dealing with a problem that occurs when the setting of another device is canceled if one device is using the network according to the demand of another device. The method of claim 9, wherein the method (c) When the request message for setting the status is transferred from the sender to the receiver, the request message is sent in consideration of the conflict situation that may occur in the middle, and only the decision operation is made by comparing with the status of the intermediate node. Operating in a manner of setting a state in the reverse direction with the request of the application arriving when the request is delivered. The method of claim 9, wherein the method (d) A method by which each device compares and determines a given request with its own state based on priorities created between the needs of the application.In the event of a conflict, the request of the application contained in the request message and the value of the state it has The higher of these replaces the needs of the application. Thus the application's request is finally determined at the moment the request message arrives at the receiver node. The method of claim 9, wherein (e) When a conflict occurs, a device with a high priority application needs to be de-configured while a device with a low priority application needs to share the settings of a device with a high priority application. A method according to claim 1, wherein a status update message is transmitted when the setting is released and the update timer expires.

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