KR20100078972A - A highspeed code radio wave protocal for updating a software on wireless sensor networks - Google Patents

Abstract

PURPOSE: A high speed code propagating protocol for updating software of a wireless sensor network is provided to apply network coding to a pipelining code propagation scheme, thereby realizing more efficient code propagation. CONSTITUTION: Node A transmits an advertisement to node B. Node B transmits an advertisement to node C. Node A decodes XOR data of node B by an advertisement message. Node A extracts an ack signal by decoding a data message from a message of node B. Node C extracts a data message by decoding an ack message pre-defined in the message of node B.

Description

A highspeed code radio wave protocal for updating a software on wireless sensor networks}

The present invention relates to a high speed code propagation protocol. More particularly, the present invention relates to an efficient software update in terms of speed, energy, and network congestion. A high speed code propagation protocol for software update on wireless sensor networks that enables reliable data transmission by avoiding decoding problems using predefined messages.

A wireless sensor network is used as a variety of information providing media after a large number of sensor nodes with limited hardware are arranged in a specific environment.

Once deployed, sensor nodes operate for long periods of time without human intervention, but require artificial software updates if they require malfunctions or performance improvements.

In order to program a sensor node, there is an ISP (In-System Programming) method that downloads a program by connecting directly to the node. Required.

Representative results of the code propagation method in the sensor network include XNP, MOAP, Deluge, and MNP. XNP was developed to update the sensor node's TinyOS kernel and application code within a single hop, sending the entire file to Code capsules.

MOAP is a technique for delivering code update data in multiple hops using the ripple propagation protocol. It provides improved functionality over data transfer and complements the one-hop limited transfer scheme of XNP.

Deluge supports multihop and uses fixed-size, page-by-page pipelining and a three-stage handshaking protocol for efficient data transfer.

MNP supports multi-hop and data is transmitted using spatial multiplexing of fixed size page unit. In addition, by using a three-step handshaking protocol and an algorithm to select the sender, unnecessary parts of the code propagation are eliminated.

Code propagation techniques in sensor networks include ripple forwarding protocols and pipelining.

The ripple transfer protocol transmits the received code to the next hop when the node of the same hop receives the entire code from the program code transmitted from the source node.

The pipeline method sends a page of program code from a source node and sends the received page to the next hop as soon as nodes of the same hop receive the page. By repeating this operation, program code propagation is completed.

The necessary components for updating the software using wireless communication are 1) Preparation Mechanism (distributing data before entering the network if the data is larger than the packet length), 2) Dissemination Mechanism, and 3) all parts of lost packets and data. There is a Reliability Mechanism for Receiving (updates are not available if the data is not received completely, to receive lost packets and complete data).

Depending on the design purpose, Message Suppression (control unnecessary messages of various protocols), Sender Selection (limit the number of active senders between neighbor nodes), and delivery methods can be added.

Dissemination protocol is a code propagation protocol for software update of a conventionally deployed wireless sensor node using wireless communication as shown in FIG.

Various conditions should be considered for efficient code propagation. Typical considerations include reliability (Reliability, sensor node can be used when the program image reception is complete), consistency, and all nodes in the network receive the entire program image. And update to the same version), small memory (Small Memory, update protocol should have a small memory footprint), energy efficiency (Energy Efficient, update protocol minimize energy usage), minimize disruption (update protocol) Because is not the main application, it should not affect the functionality of the main application), fault tolerance (allowing a node to fail or add).

The general dissemination protocol is composed of three steps, such as advertisement of a new code, selection of a source node, and data transmission to a target node as shown in FIG.

Depending on how the code is propagated, it is divided into a ripple method and a pipeline method.

As shown in FIG. 3, when a node having the same hop receives the entire code, the received code is transmitted to the next hop (Neighbor-to-Neighbor).

As shown in FIG. 4, the pipeline method transmits one page of program code from a source node to the next hop as soon as a node of the same hop receives the page. Perform this operation repeatedly to complete program code propagation.

XNP was developed to update the Sensor node's TinyOS kernel and application within a single hop. In order to reduce the amount of data to be transmitted, the code is divided into capsules to transfer the entire file. It is composed of network programming module and boot loader as a whole. Operation sequence consists of preparation of code transmission, code transmission, verification and re-programming.

MOAP is a technique for delivering update code over multiple hops using the ripple propagation protocol. It reduces network load and duplicate data transmission than data transfer method for data transfer. It also compensates for the limitation of XNP, which is limited to single hop, and the code to be updated is kept in stable storage until the update is completed. By using the retransmission scheme of lost packets based on the sliding window scheme, data loss occurs during transmission. The sequence of operations consists of code transfer preparation, code transfer, re-programming, and recovery.

However, this technique ensures that all other nodes within a single hop are in idle listening while the update code data transfer is taking place. Therefore, all nodes not involved in the update have a problem of consuming unnecessary energy.

Deluge supports multihop and uses fixed-size, page-by-page pipelining and a three-stage handshaking protocol for efficient data transfer. As shown in Fig. 5, the data representation of Deluge divides the program image into pages of fixed size. The advantage of this representation is that it limits the amount of state that must be maintained while receiving data, allowing efficient incremental update activation and spatial multiplexing from previous versions.

6 shows the basic operation of the Deluge, the detailed procedure is as follows. (a) When source node (A) broadcasts an advertisement of a new version 2 program, the nodes that receive it request node 0 for page 0, and (b) node (A) packet the page requested by the receiver. (C) Node (B) requests retransmission of the lost code, (c) Node (C, D) becomes the sender node and broadcasts the advertisement. Perform

MNP supports multi-hop and data is transmitted using spatial multiplexing of fixed size page unit. In addition, by using a three-stage handshaking protocol and an algorithm to select the sender, unnecessary parts of the code propagation are eliminated. A bit vector table is used to recover the lost code, and a code propagation and reliability mechanism is provided through a state machine composed of five basic functional states (IDLE, DOWNLOAD, ADVERTISE, FORWARD, SLEEP) as shown in FIG.

Infuse is a protocol that uses Time Division Multiple Access (TDMA), unlike other code propagation techniques. By using implicit acknowledgment and back pressure mechanisms, transmission reliability is provided. That is, to handle a failed sensor node, if the sensor node does not get an implicit acknowledgment after a predetermined delay, the sensor node retransmits. Also, TDMA Listening technique is used to save energy.

Sprinkler has reduced energy consumption compared to Deluge, Infuse, MNP and PSFQ. It provides low complexity CDS algorithm and transmits data using TDMA method like Infuse.

 Network coding is a coding scheme that is performed at the network layer and was developed to improve the transmission speed of a communication network by efficiently using communication resources. The main purpose of network coding is the compression of information, and the decoding procedure uses the information of data received from various paths of the communication network. Network coding was originally conceived for efficient multicast over the wire, but the feasibility of implementation has been demonstrated in recent wireless situations.

The basic procedure of the proposed network coding is shown in FIGS. 8 and 9. As illustrated in FIGS. 8 and 9, the nodes C and D must receive both a and b in order for the two source nodes A and B to transmit a and b information to the nodes C and D, respectively. 4, in the existing network, node a receiving the a and b should transmit b after transmitting a. However, referring to FIG. 9, the node E solves the need to be transmitted twice by transmitting Xs a and b by one transmission. Also, in the node F of FIG. 9, if the data a and b are transmitted to the nodes C and D, the number of codes can be reduced by sending the a and b results. Nodes C and D store a and b transmitted in the first slot, and then new information b and a that were not stored by XORing a and b to a and b delivered by node F, respectively. You get each of them.

This shows that theoretically optimal network efficiency can be achieved by applying network coding based on linear code in multicast network.

Network coding depends on the efficiency of the receiving node on how successfully it can decode the received coded information. For successful decoding, each node must have information for decoding in advance.

The present invention has been invented in view of the above-described circumstances, and an object thereof is to provide a high speed code propagation protocol for software update on a wireless sensor network that can achieve more efficient code propagation by applying network coding to a pipelining code propagation technique. Is in.

Another object of the present invention is to apply a network coding to the pipelining code propagation technique to update the software on the wireless sensor network, which shows a performance improvement of about 20 to 25% depending on the network environment in the number of data transmission and reception compared to the conventional pipelining method. To provide a high speed code propagation protocol.

Another object of the present invention is to apply network coding to a pipelining code propagation technique to perform efficient software update in terms of speed, energy, and network congestion, as well as loss of original data or unreceived data, which is an overhearing problem of network coding. The present invention provides a high-speed code propagation protocol for software update on a wireless sensor network that enables reliable data transmission by using a predefined message to prevent a decoding problem occurring at the time.

A high speed code propagation protocol for software update on the wireless sensor network of the present invention for achieving the above object comprises the steps of: receiving at the node (B) if an advertisement is sent at the node (A); Node B broadcasts a request to send to node A and an advertisement to send to node C by XOR; The message sent from the node B is received by the node A and the node C, and the node A decodes the XOR data sent by the node B using its own Advertisement message. The request message is then left and node B knows that it has sent an Advertisement to it; Receiving, at node B, data sent from node A and a request message sent from node C; XORing an ack signal to be sent from node B to node A and data to be sent from node C; The node A decodes the data message from the message sent from the node B to extract the ack signal, and the node C decodes the predefined Ack message from the message sent from the node B to extract the data message. Characterized in that consisting of steps.

The present invention can achieve more efficient code propagation by applying network coding to the pipelining code propagation method, and by applying network coding to the pipelining code propagation method, the network environment is improved in the frequency of data transmission / reception compared to the conventional pipelining method. In addition, the network coding is applied to the pipelining code propagation technique, which enables efficient software update in terms of speed, energy, and network congestion, as well as the overhearing problem of network coding. There is a particular advantage that reliable data can be transmitted by using a predefined message to prevent the decoding problem caused by loss or non-receipt of data.

EMBODIMENT OF THE INVENTION Hereinafter, preferred embodiment of the high speed code propagation protocol for software update on a wireless sensor network of this invention is described in detail according to an accompanying drawing.

11 is a diagram illustrating a pipelined scheme to which the present invention network coding is applied, FIG. 12 is a diagram illustrating a bidirectional linear network according to the present invention, FIG. 13 is a diagram showing a definition of a message according to the present invention, and FIG. 15A is a graph comparing the amount of data according to the number of hops, FIG. 15B is a comparison graph of data retransmission according to the number of hops, and FIG. 15C is a comparison diagram of the pipeline effect when transmitting a message. A high speed code propagation protocol for software update on a sensor network comprises the steps of: receiving an advertisement at node A and transmitting at node B; Node B broadcasts a request to send to node A and an advertisement to send to node C by XOR; The message sent from the node B is received by the node A and the node C, and the node A decodes the XOR data sent by the node B using its own Advertisement message. The request message is then left and node B knows that it has sent an Advertisement to it; Receiving, at node B, data sent from node A and a request message sent from node C; XORing an ack signal to be sent from node B to node A and data to be sent from node C; The node A decodes the data message from the message sent from the node B to extract the ack signal, and the node C decodes the predefined Ack message from the message sent from the node B to the data message. It consists of extraction steps.

According to the present invention having the configuration as shown in FIG. 12, if two nodes existing at both ends of the linearly configured network exchange information with each other by using an intermediate relay node, application of network coding may be relatively easy. In this case, there is no kind of overhearing problem.

The data transmission method of the update code includes a ripple delivery method and a pipeline delivery method. The present invention employing the pipeline delivery method reduces the code propagation time and saves energy by reducing the idle listennig time, compared to the ripple delivery method. can do.

10 is a schematic diagram of a pipeline delivery method of the existing Deluge. In pipeline delivery, the source node sends one page of program code, and as soon as the node of the same hop receives the page, it sends the received page to the next hop. By repeatedly performing this operation, program code propagation is completed.

Although more efficient than the ripple forwarding protocol, four communications are required between nodes in order to send one page. Therefore, as the number of nodes increases, the energy consumption increases exponentially.

As described above, network coding is a technique capable of sending two pieces of information in one transmission. In other words, by sending information that can be sent simultaneously to the existing pipeline delivery method, the information required for transmission decreases as the number of nodes increases. Therefore, not only energy but also transmission speed and network congestion can be reduced.

As shown in FIG. 13, Adv, Ack, and Req were previously defined to be able to decode during network transmission. The problem that occurs between decoding can be solved by equalizing the packet length of predefined Adv, Req, Data and Ack.

In FIG. 10, 1) Advertisement is sent for transmission from node A to node B. FIG. ② Node (B) sends request and ③ Node (A) sends data. ④ If node B receives data without error, it sends ack signal and node B, which has received data completely, becomes source node and sends data to node C in the same order.

In (1) of FIG. 10, 12 data transmission / reception are required to transmit data from node A to node D, whereas in FIG. 11 of the present invention, 8 is required to transmit data from node A to node D. FIG. Need to send and receive data. As described above, when the network coding technique is applied to the update code propagation, the frequency of data transmission and reception decreases as the number of nodes increases.

Next, a performance comparison between a scheme employing a high-speed code propagation protocol for software update on a wireless sensor network and a pipeline transmission scheme using Deluge, which is a conventional pipeline transmission scheme, and a network coding technique, is performed. It is shown in FIG. 15C.

It can be seen from FIG. 15A that the conventional scheme increases the transmission rate exponentially when the number of hops increases, whereas the present invention shows a stable increase rate in terms of the transmission amount even if the number of hops increases.

Accordingly, as the amount of data for transmission decreases as shown in FIG. 15B, network congestion also decreases. Therefore, even if the number of hops increases, the number of retransmissions of data is lower than that of the conventional method.

Figure 15c is a graph comparing the efficiency of the pipeline method of the existing Deluge pipeline method and the present invention. As shown in FIG. 15C, a slight difference was observed depending on the number of hops during message transmission, but the performance was improved by about 20 to 25%.

As described above, when the code update scheme proposed by the present invention is used, an efficient software update can be performed in terms of speed, energy, and network congestion. In addition, by using a predefined message, it is possible to reliably transmit data in a wireless network by preventing the loss of original data or the decoding problem due to unreceived data due to the overhearing problem, which is a problem of network coding.

While the present invention has been described as a preferred embodiment, the present invention is not limited thereto, and various modifications can be made without departing from the gist of the invention.

1 is a diagram illustrating a code propagation protocol for software update of a conventionally deployed wireless sensor node;

2 is a diagram illustrating a propagation step of a conventional dissemination protocol;

3 is a view showing a ripple scheme for software update of a conventional wireless sensor node;

4 is a diagram illustrating a pipeline scheme for software update of a conventional wireless sensor node;

5 is a view showing a data representation of the conventional Deluge,

6 is a view showing the basic operation of the conventional Deluge,

7 is a view showing a basic functional state of a conventional state machine;

8 is a block diagram of a conventional butterfly network,

9 is a configuration diagram of a butterfly network to which conventional network coding is applied;

10 is a view showing a pipelined scheme to which conventional network coding is applied;

11 is a view showing a pipeline scheme to which the present invention network coding is applied.

12 shows a bidirectional linear network in accordance with the present invention;

13 is a view showing a definition of a message according to the present invention;

14 is a diagram illustrating a decoding process of a packet format according to the present invention;

15A is a graph comparing data amounts according to hop counts;

15b is a data retransmission comparison graph according to hop number,

15c shows a comparison of pipeline effects in message transmission.

Claims (1)

Receiving at node B when Advertisement is sent at node A; Node B broadcasts a request to send to node A and an advertisement to send to node C by XOR; The message sent from the node B is received by the node A and the node C, and the node A decodes the XOR data sent by the node B using its own Advertisement message. The request message is then left and node B knows that it has sent an Advertisement to it; Receiving, at node B, data sent from node A and a request message sent from node C; XORing an ack signal to be sent from node B to node A and data to be sent from node C; The node A decodes the data message from the message sent from the node B to extract the ack signal, and the node C decodes the predefined Ack message from the message sent from the node B to extract the data message. A high speed code propagation protocol for software update on a wireless sensor network, characterized in that the step consisting of.

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