KR102052999B1 - Method and system for user priority decision in wireless body sensor network - Google Patents

Abstract

The present invention relates to a method, a system and a method for determining a user priority in a wireless human body sensor network. The method for determining a user priority in a wireless human body sensor network according to the present invention is IEEE 802.15.6 for a wireless human body sensor network. CLAIMS 1. A method for determining user priority based on MAC protocol, comprising: determining whether a record of a successful acknowledgment message relating to data communication between a transmitter and a receiver is stored in a receiver; And if it is determined that the acknowledgment message record is not stored in the receiver, determining whether to transmit the data of the priority other than the data of the highest user priority in consideration of the limitation of the energy consumption and the current channel state. Including the step, the step of determining, if the data of the remaining priority is included in the user priority of the first range, the priority determination factor value (α) of Equation 1 below is adjusted, so that the user priority of the first range Determining whether to transmit the rank data.

Description

METHOD AND SYSTEM FOR USER PRIORITY DECISION IN WIRELESS BODY SENSOR NETWORK}

The present invention relates to a method and system for determining user priorities in a wireless body sensor network (WBSN), and more particularly to low-priority data in consideration of energy consumption limitations and current channel conditions. The present invention relates to a method and system for user priority determination in a wireless human body sensor network for determining whether to transmit a message.

Wireless Body Sensor Network (WBSN) technology allows various types of wireless human body sensor devices attached to the inside and outside of a human body to form a network to communicate with other devices within a sensor range of about 3 meters. Short-range wireless communication technology to perform. WBSN technology can be classified into medical technology and non-medical technology. Medical technology mainly aims at measuring bio signals such as blood pressure and body temperature through wireless human sensor devices attached to the inside and outside of the human body. Is mainly for data transmission such as video or audio. WBSN technology with these characteristics can provide a variety of user-oriented customized application services, and has recently attracted considerable attention as a next-generation technology that enables U-Healthcare.

The most popular MAC protocol for wireless human sensor networks is the IEEE 802.15.6 standard. However, the conventional IEEE 802.15.6 MAC protocol is prone to error in the channel, and due to a complicated network environment, there is a problem in that successful data transmission cannot be guaranteed by generating data retransmission.

Therefore, there is an urgent need to develop an energy efficient wireless human sensor network while using the IEEE 802.15.6 MAC protocol.

[Related Technical Documents]

1. Two-Hop Priority Message Transmission System and Method for Energy Efficiency in WBAN (Patent Application No. 10-2015-0063722)

The problem to be solved by the present invention relates to a method and system for user priority determination in a wireless human body sensor network capable of transmitting energy-efficient data in the IEEE 802.15.6 MAC protocol for the WBSN environment.

Another problem to be solved by the present invention is to reflect the changed network topology according to the user's movement in the WBSN environment, to determine the user priority of the data to be transmitted user priority in the wireless human body sensor network that can reduce the energy consumption A method and system for ranking is provided.

Another problem to be solved by the present invention is to perform communication according to the transmission opportunity that is adaptively adjusted based on the channel state and the network congestion level (updated metric), A method and system for determining user priorities in a wireless human body sensor network capable of transmitting energy efficient data because retransmission of data can be prevented.

The objects of the present invention are not limited to the above-mentioned objects, and other objects that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to solve the above problems, the method for determining the user priority in the wireless human body sensor network according to an embodiment of the present invention is to determine the user priority based on the IEEE 802.15.6 MAC protocol for the wireless human body sensor network. A method comprising: determining whether a successful acknowledgment message record relating to data communication between a transmitter and a receiver is stored in a receiver; And if it is determined that the acknowledgment message record is not stored in the receiver, determining whether to transmit the data of the priority other than the data of the highest user priority in consideration of the limitation of the energy consumption and the current channel state. Including the step, the step of determining, if the remaining priority data is included in the user priority of the first range, the prioritization factor value (α) of Equation 1 below is adjusted to, Determining whether to transmit data of user priority.

<Equation 1>

Here, CW _min is the minimum value of the contention window, CW _max is the maximum value of the contention window, α is a priority decision factor value, and the priority decision factor value is a number between 0 and 1.

According to another feature of the invention, the prioritization factor value is a value adjusted according to Equation 2 below.

<Equation 2>

Where ef is the energy factor value and the energy factor value is a number between 0 and 1.

According to another feature of the invention, the user priority of the first range is a priority between user priorities 3 to 6 in the table of user priorities according to the traffic of IEEE 802.15.6.

According to another feature of the present invention, the acknowledgment message record is not stored in the receiver, and the data to be transmitted has priority between user priorities 0 and 2 in the table of user priorities according to the traffic of IEEE 802.15.6. In case of ranking data, the method further includes freezing a back off reduction process.

According to another feature of the invention, a transmitter comprises: storing a successful acknowledgment message record in a set channel state table; And the transmitter further updates the channel state table every set time.

According to still another aspect of the present invention, if it is determined that the acknowledgment message record is stored in the receiver, the method further includes transmitting data according to user priority according to IEEE 802.15.6.

In order to solve the above problems, the system for determining the user priority in the wireless human body sensor network according to an embodiment of the present invention is to determine the user priority based on the IEEE 802.15.6 MAC protocol for the wireless human body sensor network. A method, comprising: a plurality of nodes located within a user's body or on a skin surface to collect biometric information of the user; A gateway connecting between the plurality of nodes and the transmitter; And determining whether a successful acknowledgment message record regarding the data communication of the receiver is stored in the receiver, and if it is determined that the acknowledgment message record is not stored in the receiver, taking into account the limitation of energy consumption and the current channel state. The transmitter may include a transmitter for determining whether to transmit data of a priority other than data of the highest user priority, wherein the transmitter may include the following <if the remaining priority data is included in the user priority of the first range. The priority determination factor value α of Equation 1 is adjusted to determine whether to transmit data of the user priority of the first range.

<Equation 1>

Here, CW _min is the minimum value of the contention window, CW _max is the maximum value of the contention window, α is a priority decision factor value, and the priority decision factor value is a number between 0 and 1.

According to another feature of the invention, the prioritization factor value is a value adjusted according to Equation 2 below.

<Equation 2>

Where ef is the energy factor value and the energy factor value is a number between 0 and 1.

The present invention can provide a method and system for user priority determination in a wireless human body sensor network capable of transmitting energy-efficient data in the IEEE 802.15.6 MAC protocol for the WBSN environment.

The present invention is a method for determining the user priority in a wireless human body sensor network that can reduce the energy consumption by determining the user priority of the data to be transmitted by reflecting the changed network topology according to the user's movement in the WBSN environment and A system can be provided.

According to the present invention, a wireless human body sensor network capable of transmitting energy-efficient data can be performed by performing communication according to a transmission opportunity adaptively adjusted based on an updated metric channel state and network congestion level, thereby preventing retransmission of data. In the following description, a method and system for determining user priority may be provided.

The effects according to the present invention are not limited by the contents exemplified above, and more various effects are included in the present specification.

1 is a view for explaining a change in the network topology according to the movement of the user according to an embodiment of the present invention.
2 and 3 illustrate energy consumption after data transmission according to a method for determining user priority in a wireless human body sensor network according to an embodiment of the present invention, and energy consumption after data transmission in a protocol based on the existing IEEE 802.15.6. Experimental data compared with each other.
4 is a flowchart illustrating a method for determining user priority in a wireless human body sensor 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 in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, only the embodiments are to make the disclosure of the present invention complete, and those skilled in the art to which the present invention pertains. It is provided to fully inform the scope of the invention, and the invention is defined only by the scope of the claims.

Combinations of each block of the accompanying block diagrams and respective steps of the flowcharts may be performed by algorithms or computer program instructions, consisting of firmware, software, or hardware. These algorithms or computer program instructions may be embedded in a processor of a general purpose computer, special purpose computer, or other programmable digital signal processing device, so that instructions executed through a processor of a computer or other programmable data processing equipment. These will create means for performing the functions described in each block of the block diagram or in each step of the flowchart. These algorithms or 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 available or computer readable. It is also possible for the instructions stored in the capable memory to produce an article of manufacture containing instructions 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.

Like reference numerals refer to like elements throughout.

Each of the features of the various embodiments of the present invention may be combined or combined with each other, partly or wholly, various technically interlocking and driving as can be understood by those skilled in the art, each of the embodiments may be independently implemented with respect to each other It may be possible to carry out together in an association.

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

1 is a view for explaining a change in the network topology according to the movement of the user according to an embodiment of the present invention. First, as shown in FIG. 1, in a wireless human body sensor network (WBSN) environment, a medium access control (MAC) protocol is located on a user's human body or on the skin surface to collect biometric information. 170, the gateway 180 connecting the plurality of nodes 110 to 170 and the external node 190, and the data transmitted from the plurality of nodes 110 to 170 are transferred from the gateway 180. It consists of a receiving external node 190. Here, the external node 190 may be configured separately, or the user terminal may perform the function of the external node 190.

When determining the user priority of data to be transmitted in the WBSN environment based on the conventional IEEE 802.15.6, it is assumed that there is no change in the topology of the network. There was a problem that does not accurately reflect.

For example, as shown in Figure 1, the sensor node attached to the user's body is connected to the sensor node according to the user's movement (110 sensor node is disconnected from the 120 sensor node, 130 sensor node and Connection may be performed, and the 160 sensor node which has been connected to the 180 gateway may be disconnected).

Therefore, in one embodiment of the present invention, it is possible to determine the user priority of data to be transmitted by reflecting the changed network topology according to the user's movement in the WBSN environment, thereby reducing the energy consumption.

Hereinafter, a method and system for determining user priority in a wireless human body sensor network according to an embodiment of the present invention will be described in detail.

First, a table representing user priorities according to traffic defined in IEEE 802.15.6 is shown in Table 1 (Table 1) below.

Priority traffic CW _min CW _max 0 Background 16 64 One Best effort 16 32 2 Excellent effort 8 32 3 Controlled load 8 16 4 Video 4 16 5 Voice 4 8 6 Media data or network control 2 8 7 Emergency or medical event report One 4

In the wireless human body sensor network according to an embodiment of the present invention, the system for determining a user priority includes a plurality of nodes 110 to 170, a gateway 180, and an external node (hereinafter, referred to as a transmitter, 190).

First, a plurality of nodes (110 to 170) is located inside the user's body or the skin surface, to collect the user's biometric information, the gateway 180 is between the plurality of nodes (110 to 170) and the transmitter 190 Connect.

The transmitter 190 stores the successful acknowledgment message record with the receiver in the set channel state table, and then updates the channel state table every set time.

The transmitter 190 then determines the channel state based on the previous successful ACK history. Specifically, when it is determined that the transmitter 190 has a successful acknowledgment message record at the receiver (hereinafter, not shown), it is determined that there is no major obstacle in the current communication state, and then the data according to the priority as shown in Table 1 above. Send to the receiver.

However, if the transmitter 190 determines that the receiver does not have a successful acknowledgment message record, it determines that the current communication state is not good, and then the remaining user priority (excluding the highest user priority (priority 7) data) is determined. It is determined whether to transmit data of priorities 1 to 6).

Specifically, when the data to be transmitted to the receiver is data of user priorities 1 to 6 defined in IEEE 802.15.6, data of user priorities 1 to 6 are adjusted by adjusting a priority determination factor value. Determine whether to send to the receiver.

The method of adjusting the priority determination factor value is according to Equations 1 and 2 below.

Here, CW _min represents the minimum value of the contention window, CW _max represents the maximum value of the contention window, α is the priority decision factor value, and the priority decision factor value is a number between 0 and 1. Also, ef is an energy factor value and the energy factor value is a number between 0 and 1.

Looking at the specific operation of the transmitter 190 according to Equation 1 and Equation 2, when the data to be transmitted from the transmitter 190 to the receiver is data of user priorities 1 to 6, the transmitter 190 The energy factor value is adjusted in consideration of the energy consumption limit and the current channel state.

That is, when the transmitter 190 determines that the current channel state continues to be unstable, the transmitter 190 adjusts the energy factor value to converge to 1, and adjusts the prioritization factor value to converge to zero. As a result, according to Equation 1, the minimum value and the maximum value of the contention window become large, and the user priority of data to be transmitted to the receiver becomes a user priority of 0 to 2, thereby restricting access to the channel.

Then, the transmitter 190 freezes a backoff decrement procedure when the data to be transmitted to the receiver is user priority data between user priorities 0 and 2.

Conversely, if the transmitter 190 determines that the current channel condition is gradually stabilized, the transmitter 190 adjusts the energy factor value to converge to zero, and adjusts the prioritization factor value to converge to one. As a result, according to the above Equation 1, the minimum value and the maximum value of the contention window become small, and the user priority of data to be transmitted to the receiver becomes a user priority of 3 to 6.

Subsequently, the transmitter 190 transmits the data of the highest priority user to the receiver, and then sequentially transmits data to be transmitted to the receiver according to the determined user priority.

The remaining highest user priority data is about urgent messages, and thus is transmitted from the transmitter 190 to the receiver in the same manner as in the previous policy.

Hereinafter, a frame error rate and an energy consumption amount according to another embodiment of the present invention will be described.

First, a frame error rate (FER, Frame Error Rate) according to an embodiment of the present invention is determined according to Equation 3 below.

Where P _b is the bit error rate, d _l is the data frame bit length, and ack _l is the acknowledgment frame bit length.

In addition, the total energy consumption per one device according to an embodiment of the present invention is determined according to Equation 4 below.

Where Pidle represents energy per unit time consumed in the idle state, T _{average_backoff} represents average backoff time, and P _rx represents energy per unit time consumed in the data receiving state. , T _{average_buy} represents average channel busy time, P _tx represents energy per unit time consumed in the data transmission state, T _data represents the time it takes to transmit data, T _ack Shows the time taken to transmit acknowledgment and SIFS shows the short interframe space between data transmission and acknowledgment transmission.

2 and 3 illustrate energy consumption after data transmission according to a method for determining user priority in a wireless human body sensor network according to an embodiment of the present invention, and energy consumption after data transmission in a protocol based on the existing IEEE 802.15.6. Experimental data compared with each other.

Evaluation parameters applied in an embodiment of the present invention are shown in Table 2 (Table 2) below.

P _tx SIFS P _rx Data P _idle ACK 27 Mw 75 us 1.8 mW 150 bytes 5 uW 193 bits

In addition, the following <Table 3> (Table 3) are according to the MAC protocol in accordance with an embodiment of the present invention in the 24 node 10 ^- the average energy by the energy factor value having a bit error rate of ^third value consumption with existing IEEE This table compares the average energy consumption according to the protocol according to 802.15.6.

AP-MAC IEEE 802.15.6 UP0 [mJ] UP6 [mJ] UP6 [mJ] UP6 [mJ]
ef
0.9 1.28 4.88
1.33

5.12
0.5 1.28 4.27 0.1 1.27 5.07

As shown in FIG. 2, Table 3 and FIG. 3, the energy consumption after data transmission and the existing IEEE 802.15.6 based on the method for determining the user priority in the wireless human body sensor network according to an embodiment of the present invention. According to the protocol according to the energy consumption after the data transmission can be seen that there is a significant difference. That is, the energy consumption after data transmission according to the method for determining the user priority in the wireless human body network according to an embodiment of the present invention is compared to the energy consumption after data transmission in the existing protocol according to IEEE 802.15.6. You can see that you can save.

4 is a flowchart illustrating a method for determining user priority in a wireless human body sensor network according to an embodiment of the present invention. First, as shown in FIG. 4, the transmitter stores a successful acknowledgment message record in the set channel state table (S410).

Thereafter, the transmitter updates the channel state table every set time (S420).

Thereafter, the transmitter determines whether a successful acknowledgment message record relating to data communication between the transmitter and the receiver is stored in the receiver (S430).

If, in the above-described determination process (S430), the transmitter determines that a successful acknowledgment message record regarding data communication between the transmitter and the receiver is not stored in the receiver, the transmitter considers the limitation of energy consumption and the current channel state. Then, it is determined whether to transmit the data of the remaining priority except the data of the highest user priority (S440).

If, in the above-described determination process (S430), the transmitter determines that a successful acknowledgment message record regarding the data communication between the transmitter and the receiver is stored in the receiver, the transmitter transmits data according to an existing user priority policy. .

In this specification, each block or each step may represent a portion of a module, segment or code comprising 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.

The steps of a method or algorithm described in connection with the embodiments disclosed herein may be implemented directly in hardware, a software module or a combination of the two executed by a processor. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM or any other form of storage medium known in the art. An example storage medium is coupled to the processor, which can read information from and write information to the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside within an application specific integrated circuit (ASIC). The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

Although the embodiments of the present invention have been described in more detail with reference to the accompanying drawings, the present invention is not necessarily limited to these embodiments, and various modifications can be made without departing from the spirit of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

110 to 170 sensor nodes
180 gateway
190 External Nodes (Transmitters)

Claims (9)

In the user priority determination method based on the IEEE 802.15.6 medium access control (MAC) protocol for a wireless body sensor network,
Determining whether a successful acknowledgment (ACK) message record relating to data communication between the transmitter and the receiver is stored in the transmitter; And
If it is determined that the acknowledgment message record is not stored in the transmitter, it is determined whether to transmit the data of the priority other than the data of the highest user priority in consideration of the limitation of energy consumption and the current channel state. Including the steps of:
The determining step,
When the remaining priority data is included in the user priority of the first range, the priority determination factor value α of Equation 1 below is adjusted to determine whether to transmit the data of the user priority of the first range. And determining the user priority in the wireless human sensor network.
<Equation 1>

Here, CW _min is the minimum value of the contention window, CW _max is the maximum value of the contention window, α is a priority decision factor value, and the priority decision factor value is a number between 0 and 1. The method of claim 1,
The prioritization factor value is,
A method for determining user priority in a wireless human body sensor network, the value being adjusted according to Equation 2 below.
<Equation 2>

Here, ef is an energy factor value, and an energy factor value is a number between 0 and 1.
The method of claim 1,
The user priority of the first range is,
A method for user priority determination in a wireless human body sensor network, the priority of user priorities 3 to 6 in a table of user priorities according to traffic of IEEE 802.15.6. The method of claim 1,
If the acknowledgment message record is not stored in the receiver, and the data to be transmitted is data of priority of user priority 0 to 2 in the user priority table according to the traffic of IEEE 802.15.6, back off And freezing a backoff decrement procedure. The method of claim 1,
The transmitter storing the successful acknowledgment message record in an established channel state table; And
And wherein the transmitter further comprises updating the channel state table at a set time. The method of claim 1,
If it is determined that the acknowledgment message record is stored in the receiver, further comprising transmitting data according to user priority according to IEEE 802.15.6. A user prioritization system based on IEEE 802.15.6 MAC protocol for wireless human body sensor network,
A plurality of nodes which are located in the human body or on the skin surface of the user to collect biometric information of the user;
A gateway connecting between the plurality of nodes and a transmitter; And
It is determined whether a successful acknowledgment message record regarding the data communication of the receiver is stored in the transmitter, and when it is determined that the acknowledgment message record is not stored in the transmitter, the limitation of energy consumption and the current channel state are determined. In consideration of the above, the transmitter includes the transmitter for determining whether to transmit data of a priority other than data of the highest user priority,
The transmitter,
When the remaining priority data is included in the user priority of the first range, the priority determination factor value α of Equation 1 below is adjusted to determine whether to transmit the data of the user priority of the first range. System for determining user priorities in a wireless human sensor network.
<Equation 1>

Here, CW _min is the minimum value of the contention window, CW _max is the maximum value of the contention window, α is a prioritization factor value, and the prioritization factor value is a number between 0 and 1. The method of claim 7, wherein
The prioritization factor value is,
A system for determining user priorities in a wireless human body sensor network, the value being adjusted according to Equation 2 below.
<Equation 2>

Here, ef is an energy factor value, and an energy factor value is a number between 0 and 1. A computer-readable recording medium for recording a computer program for executing the method according to any one of claims 1 to 6.

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