KR20160130594A - Resource management method for improve reliability and connectivity between sensor nodes in wireless sensor network of ship environment - Google Patents

Abstract

A resource management method for improving reliability and connectivity between sensor nodes in a wireless sensor network in a marine environment is provided. The method includes collecting network information including a peripheral frequency channel and a PAN ID in a coordinator and setting a frequency channel and a PAN ID that are not used in the vicinity; Receiving, at the neighboring router, the set frequency channel and the PAN ID from the coordinator; And determining, in the neighboring router, whether a frequency channel being used in the vicinity is overlapped with the set frequency channel, and determining a corresponding frequency channel and a PAN ID if there is no overlapping frequency channel.

Description

Technical Field [0001] The present invention relates to a resource management method for improving reliability and connectivity between sensor nodes in a wireless sensor network in a ship environment,

The present invention relates to a resource management method for enhancing connectivity and reliability between sensor nodes by forming a mesh topology by sensor nodes forming a wireless sensor network.

 Recently, there is a growing interest in Ubiquitous Computing (Ubiquitous Computing), which provides a variety of convenient and convenient new services. This ubiquitous computing environment is based on the inclusion of computing, sensing, and communication functions in all objects. In particular, sensor network technology, which performs sensing and control functions of a human external environment, is emerging as a core technology. In other words, it is a wireless sensor network (WSN) that recognizes objects and environment by attaching an electronic tag to all objects and constructs and utilizes real-time information through the network.

Wireless sensor network is a wireless technology that can measure and detect various status and environmental information such as temperature, humidity, illuminance, pressure from a remote without a separate communication infrastructure. It can be used cheaply and effectively.

In particular, in order to monitor and control objects at a remote location, many wireless sensor nodes are distributed in a certain area to form a wireless network, and the formed network must be connected to a separate server through a wired / wireless network, It is possible to easily use the application service such as monitoring and management of the area and object through the connection to the server.

However, since the wireless sensor network is composed of a sensor, a data processing module, and a sensor node having a wireless communication module, and since the power source of the sensor node such as a battery is limited, it is necessary to use a low transmission power And an energy-efficient network protocol is required. The low transmission power of such a wireless sensor node leads to the disadvantage of a wireless sensor network having a short wireless coverage.

Therefore, in order for the ubiquitous service to be efficiently performed in a wide area, a multi-hop network in which a plurality of sensor nodes having short-range wireless links are interconnected in the space is required. Structure, and a tree structure. A cluster tree or the like may be used depending on an application service.

EEE, proposed as a standard for such wireless sensor networks. 802. 15. 4. The standard is a wireless communication technology developed for the purpose of low-power, low-cost and low-data-rate civil and industrial wireless application services. It is composed of physical layer and MAC layer It is a defined standard. As for the IEEE 802.15.4 device types, each of the nodes is divided into two types according to their functions: RFD (Reduced Function Device) and FFD (Full Function Device).

In the case of a cluster tree topology among the multi-hop networks, due to its inherent characteristics, if a node fails to communicate, the communication of other nodes in the cluster is interrupted. Such a communication failure prevents a path for transmitting data or a message of another neighboring node to the coordinator side through the corresponding node or the disabled node, and thus the wireless sensor network function of the communication area as a whole is disabled. In order to solve such a problem, an automatic network configuration function by generating a dynamic network topology for each communication node, a fault tolerance function which enables all the corresponding nodes to determine the failure and update the routing itself, Check the availability of communication from time to time. This network maintenance work requires considerable effort and cost.

In order to solve the above-mentioned problems, 802. 15. 4 standards are used to form a mesh topology and to provide a resource management method for improving reliability and connectivity between sensor nodes in a wireless sensor network in a ship environment that can enhance overall network performance.

According to an aspect of the present invention, there is provided a method of managing resources for improving reliability and connectivity between sensor nodes in a wireless sensor network in a ship environment, the method comprising: collecting network information including a peripheral frequency channel and a PAN ID in a coordinator; Setting a frequency channel and a PAN ID that are not used in the vicinity; Receiving, at the neighboring router, the set frequency channel and the PAN ID from the coordinator; And determining, in the neighboring router, whether a frequency channel being used in the vicinity is overlapped with the set frequency channel, and determining a corresponding frequency channel and a PAN ID if there is no overlapping frequency channel.

According to the present invention, IEEE. Devices using 802.14.4 standards can form a mesh topology, which can improve overall network performance.

1 is a flow diagram of forming a mesh network in accordance with an embodiment of the present invention;
2 illustrates a structure of a beacon frame in accordance with an embodiment of the present invention.
FIG. 3 is a structure of an Association Request frame according to an embodiment of the present invention; FIG.
4 is a structure of an association response frame according to an embodiment of the present invention.
5 illustrates a structure of a Channel Change Request frame according to an embodiment of the present invention.
6 is a data flow diagram in a mesh network constructed in accordance with an embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, advantages and features of the present invention and methods of achieving them will be apparent from the following detailed description of embodiments thereof taken in conjunction with the accompanying drawings.

The present invention may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of the invention to those skilled in the art. And effects of the present invention, the scope of the present invention is defined by the description of the claims.

It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. &Quot; comprises "and / or" comprising ", as used herein, unless the recited component, step, operation, and / Or added.

Figure 1 is a flow diagram of forming a mesh network in accordance with an embodiment of the present invention.

Referring to FIG. 1, a PAN coordinator collects network information including a peripheral frequency channel and a PAN ID (S210).

Next, the PAN coordinator sets up a frequency channel (idle section) and a PAN ID that are not used in the vicinity by using the collected network information (S220).

Then, the PAN coordinator transmits a beacon frame including the set frequency channel and the PAN ID information to the neighboring PAN router (S230).

Then, the PAN router, which receives the channel and PAN ID information set from the PAN coordinator, searches for a frequency being used in the vicinity, and if there is no frequency channel that interferes with the frequency channel, that is, And confirms the PAN ID (S240).

Next, the PAN router transmits a message requesting association to the PAN coordinator (S250).

When the PAN coordinator approves the connection request (S250), the PAN coordinator transmits the approval result to the PAN router as a response message to the connection request.

Then, the PAN coordinator and the PAN router configure a mesh network to perform communication for exchanging data frames (S270).

2 is a structure of a beacon frame according to an embodiment of the present invention.

Referring to FIG. 2, as described above, the PAN coordinator searches for a frequency channel and a PAN ID, and sets an unused channel and a PAN ID in the surroundings. Therefore, a beacon payload field is set in a beacon payload field (Scan CH) and PAN ID information (Scan PAN ID) of the searched neighboring network are recorded in addition to the default channel ID (Default CH) and the PAN ID information (Default PAN ID). In the beacon payload field, a timestamp field for synchronization of the entire network is further added.

FIG. 3 illustrates a structure of an Association Request frame according to an embodiment of the present invention, and FIG. 4 illustrates a structure of an association response frame according to an embodiment of the present invention.

In order to form a mesh network, when the PAN coordinator is initialized, the PAN coordinator searches for a frequency channel and a PAN ID being used in the vicinity, and receives the neighbor network information.

If the channel and the PAN ID used in the vicinity are not found, the basic channel is set as the basic communication frequency channel.

If it is determined that the basic channel is being used in the vicinity, the channel is sequentially changed one by one in the basic channel, and a channel not used in the vicinity is selected to be set as the mesh network communication frequency channel.

If the channel is first selected through the above process, the PAN ID which is not used in the vicinity is set. The PAN ID is set by first generating a provisional PAN ID, then determining whether the provisionally generated PAN ID is being used in the vicinity, setting it to the PAN ID if not used in the vicinity, and setting another temporary PAN ID And repeats the process of comparing with the PAN ID being used in the vicinity, thereby setting a PAN ID that is not used in the vicinity.

When the frequency channel and the PAN ID are set through the above process, the set channel and the PAN ID are broadcast to the PAN routers in the vicinity.

On the other hand, when the PAN router receives the set channel and PAN ID information from the PAN coordinator after initialization, it searches for and uses the network information used in the vicinity.

Also, the PAN router extends the network by transmitting the PAN ID information and the channel received from the PAN coordinator to the neighboring PAN router.

The PAN router determines whether the frequency channel being used in the vicinity overlaps with the set frequency channel received from the PAN coordinator through the received neighboring network information.

If the set frequency channel received from the PAN coordinator is recognized as a frequency channel being used in the vicinity, the PAN router requests the PAN coordinator to change the channel. The frame structure for requesting the channel change is as shown in FIG.

This frequency channel duplication acknowledgment and channel change request are repeated until the set frequency channel received from the PAN coordinator does not overlap with the frequency channel being used in the vicinity.

If no channel change request is received from the PAN router, the PAN coordinator establishes a mesh network by establishing the set frequency channel and the PAN ID as the PAN ID and channel, and performs communication through the configured mesh network.

6 is a data flow diagram in a mesh network constructed in accordance with an embodiment of the present invention.

Referring to FIG. 6, a PAN coordinator (PC) broadcasts a beacon frame at a superframe start point.

The neighboring routers R1, R2, R3, R4, and R5 check the time stamp field of the received beacon frame, and then synchronize them.

Then, routers broadcast beacon frames in their superframe period.

All the routers R1, R2, R3, R4, and R5 receive the beacon frames of their neighboring routers to determine whether there is data to be received from the neighboring routers, Mode to minimize energy consumption.

Therefore, all routers R1, R2, R3, R4, and R5 use the CFP interval to transmit data to their neighboring routers.

Router R1 informs R5 that there is data to be transmitted through the beacon frame when data to be transmitted occurs.

After confirming the beacon frame received from R1, R5 wakes up in the CFP interval allocated to itself and receives data from R1. At this point, all other coordinators and routers switch to sleep mode to minimize energy consumption.

When the router R2 generates data to be transmitted to the router R3, the CFP allocation information is also broadcast in the beacon frame.

After receiving the beacon of R2, R3 confirms the beacon and wakes up in that time slot to receive the data.

 While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, .

Claims (2)

Collecting network information including a peripheral frequency channel and a PAN ID in a coordinator and setting a frequency channel and a PAN ID that are not used in the vicinity;
Receiving, at the neighboring router, the set frequency channel and the PAN ID from the coordinator; And
Determining whether a neighboring frequency channel overlaps between the frequency channel being used and the set frequency channel in the neighboring router and determining a corresponding frequency channel and a PAN ID if there is no overlapping frequency channel;
A method of resource management for improving reliability and connectivity between sensor nodes in a wireless sensor network in a ship environment.
Collecting network information including a peripheral frequency channel and a PAN ID in a coordinator and setting a frequency channel and a PAN ID that are not used in the vicinity;
Receiving, at the neighboring router, the set frequency channel and the PAN ID from the coordinator;
Determining whether a neighboring frequency channel overlaps with the set frequency channel and determining a corresponding frequency channel and a PAN ID if there is no overlapping frequency channel;
Transmitting a message requesting association to the coordinator from the router when the corresponding frequency channel and the PAN ID are determined; And
When the coordinator approves the connection request, transmitting a result of the approval to the router as a response message to form a mesh network between the coordinator and the router;
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