KR20170126777A - Device for Wireless Network and Communication Method thereof - Google Patents

Abstract

An embodiment of the present invention provides a hub apparatus for data communication in a wireless network communication system, and a communication method of a device. A data communication method of a hub apparatus constituting a wireless communication system comprises steps of: receiving a request for allocating a guaranteed time slot (GTS) including information of data size to be transmitted from each of a plurality of devices to the hub apparatus; determining a superframe order (SO) for the plurality of devices based on size information of data received from each of the plurality of devices; and allocating a GTS corresponding to the determined SO to a GTS of the plurality of devices. According to the embodiment of the present invention, it is possible to suppress battery power from being wasted in a hub apparatus and a device which is a terminal apparatus.

Description

[0001] The present invention relates to a device for configuring a wireless network and a communication method therefor,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system, an apparatus, and a communication method for configuring a wireless network, and more particularly, to a data communication method and apparatus for allocating guaranteed time slots to devices in a wireless network communication system.

Recently, wireless networks have attracted much attention as one of the key supporting technologies in fields such as Internet on Things (IoT) construction, home automation, and industrial automation.

For example, the technology in which IoT is constructed is connected to the wireless personal area network (WPAN) of the home appliances in the smart home to exchange data and organically communicate with each other.

However, a hub device serving as a coordinator among the IoT devices constituting the smart home uses non-beacon IEEE 802.15.4. Therefore, a hub device using non-beacon IEEE 802.15.4 has a problem that it does not support high reliability, high bandwidth utilization, high throughput and low power consumption. Further, the hub device using the non-beacon mode has a limited performance because of its low performance, limited network coverage, and limited number of terminal devices connected to the hub device.

Meanwhile, terminal devices connected to the hub device can provide QoS (Quality of Service) using a GTS (Guaranteed Time Slot) of a superframe. The hub device receives a GTS request message from the terminal device, allocates the GTS to the terminal device, and receives a GTS allocation cancel message from the terminal device. Accordingly, even if the terminal device does not transmit or receive data in the allocated time slot, the time slot bandwidth of the GTS allocated to the terminal device before the hub device receives the GTS allocation cancel message from the terminal device in the GTS interval of the superframe, And the power consumption is wasted.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a data communication method and apparatus for GTS allocation capable of improving the performance of a hub device and a device constituting a wireless network. have.

It is another object of the present disclosure to provide a method and apparatus for modifying the IEEE 802.15.4 communication standard to maintain compatibility with the IEEE 802.15.4 wireless network standard, A communication method and apparatus are provided.

According to an aspect of the present invention, there is provided a data communication method of a hub apparatus for configuring a wireless communication system, the method comprising: receiving, from each of a plurality of devices, Determining a superframe order (SO) for the plurality of devices based on size information of data received from each of the plurality of devices, receiving a GTS (Guaranteed Time Slot) And allocating a GTS corresponding to the determined superframe order to a GTS of the plurality of devices.

According to an aspect of the present invention, there is provided a hub apparatus for configuring a wireless communication system, including: a communication unit for transmitting and receiving data to and from a plurality of devices; (GTS) allocation request including size information of a data to be transmitted to a plurality of devices, and transmits a super frame order (SO) to the plurality of devices based on size information of data received from each of the plurality of devices , Superframe Order), and assigns GTSs corresponding to the determined superframe order to GTSs of the plurality of devices.

According to another aspect of the present invention, there is provided a device for configuring a wireless network system including a communication unit for transmitting and receiving data to and from a hub device, and a communication unit for transmitting data size information of a device to be transmitted to the hub device Receiving a GTS (GTS) allocation request to the hub device, receiving GTS allocation information for the device from the hub device, determining a transmission / reception mode of the device based on the GTS allocation information, And a processor for controlling the communication unit to transmit and receive data to and from the hub device based on the determined transmission / reception mode.

According to another aspect of the present invention, a wireless network system receives a GTS (Guaranteed Time Slot) allocation request including size information of data to be transmitted from a plurality of devices, , Determining a superframe order (SO) for the plurality of devices based on size information of data received from each of the plurality of devices, determining a superframe order (SO) corresponding to the determined superframe order, (GTS) allocation request including a hub size allocated to a GTS of a device and data size information of a device to be transferred to the hub device, and receives GTS allocation information for the device from the hub device And determines the transmission / reception mode of the device based on the received GTS allocation information And, a device for transmitting and receiving the hub device and the data based on the determined transmission mode.

The device and the data communication method of the wireless network according to the present invention can reduce the power consumption of the device effectively by having different power states according to the data transmission / reception mode in the GTS interval in which the device is allocated .

In addition, the apparatus for configuring a wireless network and the data communication method according to the present invention as described above can increase the number of devices connected to a hub device, reduce wasted bandwidth, and expand network coverage The performance of the network can be improved.

1a and 1b are a general illustration of a wireless network topology for providing Internet on Things (IoT) services,
FIG. 2 is an IEEE 802. FIGS. 1A and 1B are a general illustration of a wireless network topology for providing Internet on Things (IoT)
2 is a diagram showing a structure of a super frame used in the IEEE 802.15.4 system,
3 is a flowchart showing a data communication procedure according to GTS allocation between a hub apparatus and a terminal apparatus in an IEEE 802.15.4 system;
4 is a diagram illustrating a method for reducing GTS bandwidth waste according to one embodiment of the present disclosure;
5 is a diagram for explaining a GTS allocation request command frame of IEEE 802.15.4 according to an embodiment of the present disclosure;
6 is a flow chart illustrating a GTS allocation method of a hub device, according to one embodiment of the present disclosure;
7 is a flowchart showing a data communication method according to a GTS allocation request of a device that is a terminal device according to an embodiment of the present disclosure;
8 is a flowchart showing a data communication method of a hub apparatus and a terminal apparatus according to an embodiment of the present disclosure;
Fig. 9 is a graph for explaining a reduction in power consumption in the hub device and the terminal device, according to an embodiment of the present disclosure; and
10 is a simplified block diagram of a hub device and a terminal device according to an embodiment of the present disclosure;

It is noted that the technical terms used herein are used only to describe specific embodiments and are not intended to limit the invention. It is also to be understood that the technical terms used herein are to be interpreted in a sense generally understood by a person skilled in the art to which the present invention belongs, Should not be construed to mean, or be interpreted in an excessively reduced sense. Further, when a technical term used herein is an erroneous technical term that does not accurately express the spirit of the present invention, it should be understood that technical terms that can be understood by a person skilled in the art are replaced. In addition, the general terms used in the present invention should be interpreted according to a predefined or prior context, and should not be construed as being excessively reduced.

Also, the singular forms "as used herein include plural referents unless the context clearly dictates otherwise. In the present application, the term "comprising" or "comprising" or the like should not be construed as necessarily including the various elements or steps described in the specification, Or may be further comprised of additional components or steps.

Further, the suffix "part" for a component used in the present specification is given or mixed in consideration of ease of specification, and does not have a meaning or role that is different from itself.

Furthermore, terms including ordinals such as first, second, etc. used in this specification can be used to describe various elements, but the elements should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

The term " hub device "in the present disclosure may denote a" coordinator "for controlling devices that are in wireless data communication with each other in a wireless communication network, Quot; device ".

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or similar elements, and redundant description thereof will be omitted.

1A and 1B are general illustrations of a wireless network topology for providing Internet on Things (IoT) services.

Figure 1a illustrates a star topology network topology, and Figure 1b illustrates a tree topology network topology.

In the short distance wireless communication such as WPAN / WLAN (Wireless Personal Area Network / Wireless LAN), the devices 100-1 to 100-6 and the hub device 200 use a time concept called a super frame to perform data communication .

1A, the star network topology in the smart home 10 is a topology in which the hub device 200 includes a plurality of devices 100-1, 100-2, 100-3, 100-4, 100-5, and 100-6 ). The hub device 200 is one of FFDs (Full Function Devices) and transmits a beacon signal as a coordinator device. The other devices 100-1, 100-2, 100-3, and 100- 4, 100-5, and 100-6).

Referring to FIG. 1B, a tree type network topology includes a plurality of devices 100-1, 100-2, 100-3, 100-4, 100-5, 100-6, and 100 -7, 100-8, 100-9). Each of the devices 100-1, 100-2, 100-3, 100-4, 100-5, 100-6, 100-7, 100-8, and 100-9 can communicate with any other device in the network have. Thus, a tree-type (peer-to-peer) topology can constitute a complex type of network. Thus, the tree topology has high data reliability and connection recognition rate.

For example, the hub device 200 may be a coordinator device that processes resources of a device in a wireless network system. The hub device 200 may be connected to smart sensors, lights, locks, cameras, etc. through a wireless network in a smart home. The above-described examples are illustrative of the present disclosure, but are not limited thereto.

The devices 100-1, 100-2, 100-3, 100-4, 100-5, 100-6, 100-7, 100-8, and 100-9 are connected to the hub device 200 via a wireless network Or a device including sensors. For example, a device may be doors, windows, cabinets, or garage with sensors attached thereto to monitor door opening and closing. The device may also be a sensor attached to monitor movement of an object or user at home. Further, the device may be an outlet for controlling an electronic device or the like. The device may be numerous devices that are in wireless communication with the hub device 200 over a wireless network.

Currently, the devices that make up the smart home are star topology type networks. However, as the use range of IoT is expanded, a smart home can be constructed through a network in the form of a tree topology. A star topology may have limited network coverage than a tree topology. In addition, devices constituting a network in the form of a tree topology can transmit and receive data sizes larger than devices constituting a star topology type network.

The superframe structure of IEEE 802.15.4 is determined by the hub device 200 which is a coordinator device. The GTS allocation of the current IEEE 802.15.4 superframe does not take into account the resources of the device. Thus, according to one embodiment of the present disclosure, there is a need for a modification of the IEEE 802.15.4 standard that can reflect the resources of the device and can also be applied to a tree topology. A modification of IEEE 802.15.4 according to an embodiment of the present disclosure will be described in detail in Figs. 4-10.

2 is a diagram showing a structure of a super frame used in the IEEE 802.15.4 system.

Referring to FIG. 2, the superframe structure is determined by the hub device, and informs the device of the superframe information via the beacon signal. The device receiving the beacon signal is in synchronization with the short-range wireless network.

The interval between the beacon signal and the next beacon signal is divided into an active interval and an inactive interval. The beacon signal includes a Superframe Order (SO) value and a Beacon Order (BO) value that determine the structure of the super frame. SO and BO are determined by the hub device 200. [ For example, when there is a large amount of data to be transmitted, the SO value and the BO value may be assigned a large value, and if the data is real-time traffic, the BO value may be a small value.

After receiving the beacon, the device determines the beacon interval (BI, Beacon Interval) with the BO value, and determines the active period (SD, Superframe Duration) with the SO value.

The SD (Superframe Druation) 210 is the length of the active period composed of 16 slots of the same interval. The active section 210 compares with a content access period (CAP) that compares with another device and communicates with a GSMA / CA (Carrier Sense Multiple Access / Collision Avoidance) algorithm method. And a contention free period (CFP) 220 composed of a GTS (Guaranteed Time Slot) to which a predetermined period of a super frame is allocated.

The GTS allocation is made when the device requests GTS allocation to the hub device and requests GTS deallocation in order for the device to stop using the GTS. The hub device 200 determines to which device each GTS constituting the GTS is allocated. The GTS can be configured to include a maximum of seven. Further, a plurality of GTSs can be assigned to one device. That is, once a device is assigned a GTS, other devices can not use that GTS until it issues a disassociation request. In addition, the GTS deassignment may be released by a specific rule predetermined by the hub device.

The SD (Superframe Duration) 210 is an active period in which data transmission / reception is performed between the device 100 and the hub device 200, and the SD length is extended as the superframe order (SO) increases. SD = aBaseSuperframeDuration * 2 ^SO and 0 = <SO = <BO (Beacon order) = <14. At this time, if SD = 14, there is no inactive period in the superframe. The allocation of the GTS is determined in the SD 210 and the remaining interval is used as the CAP. Therefore, the allocation of the GTS and the use of the GTS in the SD 210 determines the superframe and affects the beacon interval (BI). During the beacon interval (BI), devices are active in the active period and stay in the sleep mode in the inactive period to receive the beacon signal.

That is, in the superframe structure according to the IEEE 802.15.4 standard, the SD value increases as the SO increases. Increasing the SD value means that the bandwidth that can be provided per slot is increased. Therefore, as the SO increases, the resources may be allocated more than the bandwidth required by the device, and the bandwidth may be wasted. For example, if the size of the data (resource) that the device wants to transmit is small, but the SO for which the device requested the GTS has a high value, the SD value may be larger than the bandwidth required by the device due to the high SO value. In addition, the device must operate in the active mode in the CAP interval and the GTS interval allocated thereto. Thus, the device may be inefficient in power consumption.

3 is a flowchart illustrating a data communication procedure according to GTS allocation between a hub apparatus and a terminal apparatus in an IEEE 802.15.4 system.

In step S310, when there is data to be transmitted to the hub device 200, the terminal device 100 may transmit a message including a GTS request command to the hub device 200 to request GTS allocation. The GTS request command is transmitted to the hub device 200 through a message included in the GTS Characteristics field.

In step S320, the hub device 200 transmits an ACK (acknowledgment) to the terminal device 100 when determining the GTS allocation for the terminal device.

In step S330, the hub device 200 transmits the beacon message including the GTS information allocated to the device to the terminal device 100. [

In step S340, the terminal device 100 transmits and receives data with other devices including the hub device 100 using the GTS allocated based on the beacon message received from the hub device 100. [

In step S350, when the terminal apparatus 100 desires not to use the GTS allocated to the terminal apparatus 100, the terminal apparatus 100 transmits a GTS request command to the hub apparatus 200. [

That is, the "GTS request command" which is the GTS allocation request includes the GTS allocation request in step S310 and the GTS release request in step S350.

In step S360, the hub device 200 retrieves the GTS allocated from the terminal device 100 and transmits an ACK to the terminal device 100. [

Therefore, even if the terminal 100 does not currently use the GTS allocated thereto, the GTS allocation method according to the IEEE 802.15.4 standard is a method in which the terminal 100 allocates the GTS to the hub 200 There is a problem that the GTS can not be used by other terminal devices.

4 is a diagram illustrating a method for reducing GTS bandwidth waste according to one embodiment of the present disclosure.

FIG. 4 shows CAPs and CFPs, which are active periods of the superframe described with reference to FIG. In FIG. 4, two GTS slots 420 are illustrated in the CFP section, but this is only one example for explaining the present disclosure. In the IEEE 802.15.4 communication standard, the CFP section includes a maximum of seven GTS slots 420 .

The GTS slots 420 and 420-1 include an available transmission period 450 and an interframe space (IFS) 450-1. The time slots 430 and 430-1, which are negative in the data transmission enable periods 450 and 450-1 and in which the actual data is transmitted (460 and 460-1, packet tramsmission period), are wasted Bandwidth 430, 430-1, wasted BW.

The upper graph of FIG. 4 is an active period showing that two terminal devices are allocated to respective GTSs when the superframe order (SO) is 6 according to the IEEE 802.15.4 communication standard. For example, each terminal apparatus may transmit a 90-byte packet to the hub apparatus. When SO is 6, each GTS length 420 is 3.84 ms, IFS is 0.64 ms, and the time 460 required for each packet to be transmitted to the hub device at each terminal is 1.6 (including IFS ms. Therefore, according to the conventional data transmission method by GTS allocation, the terminal apparatus has 2.24 ms (430) = 3.84 ms (420) - 1.6 ms (460) which is 58% of the GTS length 420 of 3.84 ms allocated to the terminal apparatus ) Can be wasted.

On the other hand, the lower graph of FIG. 4 is an active period showing that the GTS is allocated by determining an optimal SO based on the data size to be transmitted by the terminal according to an embodiment of the present disclosure.

According to one embodiment of the present disclosure, when a terminal device intends to transmit 90 bytes of data to a hub device, the hub device can determine the optimal GTS length required to transmit 90 bytes. The hub device can determine the SO value corresponding to the GTS required to transmit 90 bytes. For example, when SO = 1, 90 bytes of data can be transmitted in the GTS section. Therefore, the hub device can allocate the GTS section length when SO is 1 to the GTS of each device. At this time, as described above with reference to FIG. 2, the length of the active period in the superframe is the CAP interval after the GFP interval length of the CFP is determined. Accordingly, since the length of the GTS section corresponding to 90 bytes is shortened to the length of the SO value of 1, the length of the CAP section may be longer than that of the upper graph of FIG. Further, when SO = 1, the GTS length 420-1 may be 1.92 ms. Since the time taken to transfer 90 bytes of data to the hub device is 1.6 ms, the bandwidth wasted in the GTS interval may be 1.92 ms (420-1) -1.6 ms (460-1) = 0.32 ms (430-1) . Thus, in the GTS allocation according to one embodiment of the present disclosure, the bandwidth waste at the terminal may be 17% of the GTS length 420-1. The above-described data sizes and times are only examples for explaining the present disclosure, but are not limited thereto.

5 is a diagram illustrating a GTS request command frame of IEEE 802.15.4 according to an embodiment of the present disclosure.

Referring to FIG. 5, the GTS request command in the IEEE 802.15.4 communication standard includes a GTS characteristics field 510. The GTS property field 510 includes the nature and characteristics of the GTS requested from the device 100 to the hub device 200. The GTS property field 510 includes a GTS length, a GTS direction, a characteristic type, and a Reserved field.

The GTS length field indicates how many superframe slots the GTS should comprise. The GTS direction field indicates whether the corresponding GTS is used by the device for receiving purposes or for transmission purposes. The property type field indicates whether the corresponding GTS request command is used for GTS allocation or GTS recovery.

In accordance with one embodiment of the present disclosure, the size information of the data (packet) that the device 100 wants to transmit to the hub device 200 includes a 4-bit GTS length field 520 and a 2-bit Reserved field 530 May be included and sent to the hub device 200 as a GTS request message.

For example, if the data size to be transmitted by the device 100 is 20 bytes or more and less than 133 bytes, the data size information may be included in the GTS length 520 field having a 4-bit value. At this time, the data size field 520 having a 4-bit value may be applied when the star topology network is used. In addition, when the data size to be transmitted by the device 100 is 133 bytes or more and 516 bytes or less, the data size information may be included in the Reserved (530) field having a 2-bit value. That is, according to one embodiment of the present disclosure, the Reserved 530 of the GTS property field 510 may indicate a sub-field including data size information of a predetermined size or more. At this time, the data size field 530 having a 2-bit value can be applied to a tree topology network. The data sizes included in the data size fields 510 and 530 according to an embodiment of the present disclosure may be implemented as shown in Table 1, but this is only one example for illustrating the present disclosure and may be implemented in various ways.

 Method for Modification of GTS Request Command Total Data size (bytes) Bits: 0-3 Bits: 6-7 Total Data size (bytes) Bits: 0-3 Bits: 6-7 20-26 0000 00 261-268 0000 10 27-33 0001 00 269-276 0001 10 34-40 0010 00 277-284 0010 10 41-47 0011 00 285-292 0011 10 48-54 0100 00 293-300 0100 10 55-61 0101 00 301-308 0101 10 62-68 0110 00 309-316 0110 10 69-75 0111 00 317-324 0111 10 76-82 1000 00 325-332 1000 10 83-89 1001 00 333-340 1001 10 90-96 1010 00 341-348 1010 10 97-103 1011 00 349-356 1011 10 104-111 1100 00 357-364 1100 10 112-119 1101 00 365-372 1101 10 119-126 1110 00 373-380 1110 10 127-133 1111 00 381-388 1111 10 133-140 0000 01 389-396 0000 11 141148 0001 01 397-404 0001 11 149-156 0010 01 405-412 0010 11 157-164 0011 01 413-420 0011 11 165-172 0100 01 421-428 0100 11 173-180 0101 01 429-436 0101 11 181-188 0110 01 437-444 0110 11 189-196 0111 01 445-452 0111 11 197-204 1000 01 453-460 1000 11 205-212 1001 01 461-468 1001 11 213-220 1010 01 469-476 1010 11 221-228 1011 01 477-484 1011 11 229-236 1100 01 485-492 1100 11 237-244 1101 01 493-500 1101 11 245-252 1110 01 501-508 1110 11 253-260 1111 01 509-516 1111 11

6 is a flow chart illustrating a GTS allocation method of a hub device, in accordance with an embodiment of the present disclosure;

In step S610, the hub device 200 may receive the device's GTS request from the device 100 during the CAP interval shown in FIG. The GTS request may include a GTS allocation request and a GTS allocation termination request. The device 100 may transmit a GTS request message to the hub 200 including the data size information to be transmitted to the hub 200. [

At this time, the hub device 200 can receive a GTS request from at least one device 100. [ Hub device 200 may receive a GTS request from a plurality of devices. At this time, if the GTS request cancel message is included in the GTS request message received from a plurality of devices, the hub device 200 may first perform GTS allocation termination. The hub device 200 can proceed to the remaining steps after performing the GTS allocation cancellation.

In step S620, the hub device 200 may determine the data size of the device included in the GTS request message. As described above with reference to FIG. 5, the data size information included in the GTS request message is included in the 4-bit data size field when the data size is less than the preset first value, May be included in the data size field of FIG.

In step S630, the hub device 200 may determine the superframe order according to the data size information included in the GTS request message. The hub device 200 can determine the superframe order having the slot length of the optimal GTS that can transmit the data size.

At this time, the hub device 200 can determine the data size according to the GTS request of the device 100 when the GTS of the super frame is allocated to a predetermined number or less. For example, in the IEEE 802.15.4 communication standard, the hub device 200 can allocate up to seven GTSs to the device 100. Therefore, the hub device 200 may perform step S630 if seven unassigned GTSs among the seven GTSs are seven or less. That is, if seven GTSs are all allocated and the hub device 200 receives a GTS request from the device 100, the hub device 200 sends an ACK not accepting the GTS request of the device 100 to the device 100, Lt; / RTI &gt;

The hub device 200 can determine the time required for the data having the data size included in the GTS request message to arrive at the hub device 200. [ The hub device 200 can determine the data arrival time using the data size information, the GTS allocation delay time, the GTS request arrival time, and the packet generation rate of the data. The packet generation rate of the data may indicate the rate at which the data having the data size that the device 100 desires to transmit is packetized. The GTS allocation delay time may include a delay time such as the interframe spacing (IFS) shown in Fig. The above example is only an example and the hub device 200 can use various data and methods to determine the time required for the data of the data size that the device 100 wants to transfer to the hub device 200 to be transmitted .

The hub device 200 transmits the data size to be transmitted by the device to the optimal superframe required for transmitting the corresponding data size by using the power consumption efficiency, the allocation delay efficiency, the bandwidth utilization efficiency, and the throughput efficiency of the hub device. Order can be judged.

The power consumption efficiency may be a value obtained by dividing the power consumption according to an embodiment of the present disclosure by the power consumption consumed by the IEEE 802.15.4 standard. The allocation delay efficiency may be a value obtained by dividing the GTS allocation delay time according to an embodiment of the present disclosure by the GTS allocation delay time according to the IEEE 802.15.4 standard. The bandwidth utilization may be a value obtained by dividing the bandwidth usage according to an embodiment of the present disclosure by the total bandwidth amount. The throughput efficiency may be the throughput according to one embodiment of the present disclosure divided by the maximum throughput.

For example, when two devices are connected to the hub device 200 and GTSs are allocated to two devices, a delay time of 2 ms may occur. However, when seven devices are connected to the hub device 200 and GTSs are allocated to seven devices, a delay time of 20 ms may occur. Accordingly, the hub device 200 can determine the optimal SO suitable for the GTS requested by each device based on the bandwidth utilization efficiency and the throughput according to the number of devices connected to the hub device 200 and the data size of each device . However, the above-described examples are only illustrative of the present disclosure and are not limited thereto.

In step S640, the hub device 200 can allocate a GTS to the device 100 based on the determined superframe order.

The hub device 200 may allocate the GTS to the device 100 if the data arrival time of the device 100 is less than or equal to the total time of the unallocated slots of the GTS slots.

In step S650, the hub device 200 may transmit a beacon signal including the GTS assignment information to the device 100. [

For example, the current superframe order is SO = 6, the data size to be transmitted by the first device is 90 bytes, and the data size to be transmitted by the second device is 120 bytes. At this time, the data size information of the first device and the data size information of the second device may be included in the 4-bit data size field, which is a subfield of the GTS property field, and may be transmitted to the hub device 200 as a GTS request message.

Based on the data size information of each of the first device and the second device, the hub device 200 can determine the time at which each data arrives at the hub device 200, and the optimal superframe Order can be judged. The hub device 200 allocates the GTS slot length corresponding to the optimal superframe order corresponding to 90 bytes of the first device to the first device and corresponds to the optimal superframe order corresponding to 120 bytes of the second device Lt; RTI ID = 0.0 &gt; GTS &lt; / RTI &gt; The hub device 200 may transmit a beacon signal including GTS information allocated to each device to each device. Each device can transmit and receive data in the GTS section allocated based on the beacon signal received from the hub device 200. [

7 is a flowchart illustrating a data communication method according to a GTS allocation request of a device that is a terminal device according to an embodiment of the present disclosure.

In step S710, the device 100 may receive a beacon signal from the hub device 200 notifying the start of the superframe.

In step S720, the device 100 may transmit a GTS request message including the data size information to be transmitted to the hub device 200 to the hub device 200. [

The GTS request may include a GTS allocation request and a GTS termination request. If the GTS request is a GTS revocation request, the device 100 may not transmit data size information. The data size information may be included in the 4-bit size information field 520 and the 2-bit size information field 530 of the GTS characteristic field shown in FIG. At this time, if the data size is less than the predetermined value, the data size information is included in the size information field 520 of 4 bits, so that the GTS request can be transmitted to the hub device 200. If the data size is greater than or equal to the predetermined value, the data size information is included in the size information field 530 of 2 bits so that the GTS request can be transmitted to the hub device 200.

In step S730, the device 100 may receive a GTS assignment response (ACK) message from the hub device 200. [

In step S740, the device 100 may receive the beacon signal including the GTS allocation information from the hub device 200. [

In step S750, the device 100 may determine a data transmission / reception mode for transmitting / receiving data in the allocated GTS. In FIG. 5, the GTS Direction field indicates whether the GTS assigned to the device 100 is used for a reception purpose or a transmission purpose.

When data is received from the hub device 200 in the allocated GTS interval, the device 100 may determine the transmission / reception mode to be the reception mode in the first mode. On the other hand, when data is transmitted to the hub device 200 during the allocated time slot, the device 100 may determine that the transmission / reception mode is the transmission mode of the second mode.

In step S760, the device 100 can control the on / off of the RX / TX of the communication unit according to the determined data transmission / reception mode.

In the first mode, the receive mode, the device 100 turns on the RF (Radio Frequency) receive (RX) included in the device 100 during the assigned time slot and turns off the RF transmit TX The RF communication unit can be controlled. In the first mode of transmission, the device 100 can control the communication unit such that the TX of the communication unit of the device 100 is turned on and the RX of the communication unit is turned off during the assigned time slot.

 Thus, in accordance with the embodiments of the present disclosure, the device 100 can reduce the power consumed by the device 100 since the RX / TX of the communication unit is not continuously turned on simultaneously during the allocated GTS interval.

At this time, in various embodiments of the present invention, "on" and "off" can be used to turn on / off the RF transceiver of the sensor attached to the device 100, It can mean to do. However, this is only one embodiment for facilitating the description of the present invention, and it is also possible to implement the device 100 on / off from another chip that controls the communication power of the device 100 when the device 100 performs communication with the hub device 200 .

8 is a flowchart showing a data communication method of a hub apparatus and a terminal apparatus according to an embodiment of the present disclosure.

In step S810, the terminal device 100 may transmit the data size information to be transmitted to the hub device 200 by the terminal device 100 to the hub device 200 through the GTS property field.

In step S820, the terminal device 100 may transmit a GTS request message including data size information to the hub device 200. [ The GTS request message may include a GTS allocation request and a GTS termination request.

The GTS request may be sent to the hub device 200 during the CAP interval of the active period of the superframe. The information (I) included in the GTS request can be represented by a set, but the data included in the set is an example for explaining the present disclosure, but is not limited thereto.

I is the total number of GTS requests during the CAP interval, D _i is the data size included in the GTS allocation request, _i = {(D _i , A _i , T _i , R _i ) (bytes), and GTS termination request, not considering the data size, a _i is a maximum allowed delay time (ms), T _i are generated data is generated by the packet from the terminal apparatus GTS request arrival time (ms), R _i Packet generation rate.

In step S830, the hub device 200 may determine whether there is a GTS release request in the GTS request message received from the terminal device 100. [ For example, the hub device 200 may receive a GTS request from a plurality of terminal devices. The hub device 200 can receive a GTS request in order of requests from a plurality of terminal devices. According to an embodiment of the present disclosure, when at least one GTS release request among a plurality of GTS requests received from a plurality of terminal devices is included, the hub device 200 performs GTS release first, Can be performed. Accordingly, the hub device 200 according to an embodiment of the present disclosure can reduce power consumption and bandwidth waste in the device 100 compared to a method of processing a GTS allocation / release request by a conventional FIFO (first in first out) method .

In step S840, the hub device 200 may transmit an acknowledgment message (ACK) to the terminal device 100 indicating that it has received the GTS request.

In step S850, the hub device 200 may determine the superframe order according to the data size information included in the GTS allocation request message.

The superframe order is one of the set values SO = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14} .

The hub device 200 can determine the optimal superframe order corresponding to the data size of the device 100 using a performance metric. The performance metric M = a ₁ * Power efficiency + a ₂ * Delay efficiency + a ₃ * Bandwidth utilization + a ₄ * Throughput efficiency. Here, a ₁ , a ₂ , a ₃ and a ₄ may be a ₁ + a ₂ + a ₃ + a ₄ = 1 as co-efficient factors. The performance metric described above may be extended to other performance metrics and coefficients, but is not limited thereto.

The other performance metrics are, for example, the power consumption efficiency, the allocation delay efficiency, the bandwidth utilization efficiency, and the throughput of the hub device 200 when the device 100 described in the step 630 of FIG. 6 transmits the data size to be transmitted. Efficiency, but is not limited thereto. In addition, various performance calculation methods and the like can be used to calculate the performance metric of the hub device 200. [ In addition, various methods of capturing IEEE 802.15.4 packets can be used to determine the packet generation rate of the data size.

When the hub device 200 receives a GTS request from each terminal device among a plurality of terminal devices, the hub device 200 may assign a GTS to the terminal device in a first in first out order to the unassigned GTS.

At this time, the slot length in the current SO (Superframe Order) of each device can be calculated using the SD (Superframe Duration) = aBaseSuperframeDuration * 2 ^SO formula. SO can have a value from 1 to 14.

Based on the GTS request information received from each device, the hub device 200 determines the time required for each device to transmit data having a data size to be transmitted to the hub device 200 to the hub device 200 can do. For example, the time required for data to be transmitted t = data size * 2.28 + 0.64 (ms). The hub device 200 transmits a GTS request when the required time t is longer than the number of slots not yet allocated, multiplied by the slot length, minus the number of slots already allocated among the maximum number of slots (e.g., 7) of the GTS You may not accept it. For example, the hub device 200 may reject a GTS request if t > (7 # of allocated slots) * slot length (ms).

On the other hand, if t = <(7- # of allocated slots) * slot length (ms), the hub device 200 can allocate a GTS to each device in order from the GTS slot not yet allocated.

Through the above-described method, the hub device 200 can determine the SO value having the optimum efficiency in the data size of each terminal device, and allocate the GTS slot length corresponding to the SO value to the terminal device as the GTS.

In step S860, the hub device 200 may transmit to the terminal device 100 a beacon signal including information on the GTS allocated to the determined superframe order.

In step S870, the terminal device 100 can transmit / receive data to / from the allocated GTS after receiving the beacon signal, and can determine the data transmission / reception mode based on the data reception and transmission information. When data is received from the hub device 200 in the allocated GTS interval, the terminal device 100 can determine that the first mode is the data reception mode. Also, when data is transmitted to the hub device 200 in the allocated GTS interval, the terminal device 100 can determine the second mode, which is the data transmission mode.

In step S880, the terminal device 100 turns off RX (Receive) of the communication unit of the terminal device 100 and turns on TX (transmit) when transmitting (transmitting) data in the GTS section .

In step S890, when receiving data in the GTS section, the terminal device 100 can turn on the RX of the communication unit of the terminal device 100 and turn off TX.

In step S895, if the terminal device 100 desires not to use the allocated GTS any more, the terminal device 100 may transmit a GTS deallocation request to the hub device 200. [

In step S897, the hub device 200 may transmit a GTS release acknowledgment (ACK) message to the terminal device 100. [

Through the above-described method, the apparatuses constituting the wireless network according to the embodiments of the present disclosure can improve the network reliability and reduce the power consumption in the GTS slot. In addition, the devices according to the embodiments of the present disclosure can increase the bandwidth utilization efficiency, thereby connecting a greater number of terminal devices to the network and increasing the throughput. In addition, the methods described above can be applied to both star topology networks and tree topology networks.

9 is a graph for explaining a reduction in power consumption in a hub device and a terminal device according to an embodiment of the present disclosure.

9 is a graph showing power consumption according to a beacon frame order when seven (sensor) devices are connected to the hub device 200 and the data size to be transmitted by each device is 95 bytes. According to one embodiment of the present disclosure, when the data size is 95 bytes, the optimum superframe order is determined to be 2 (SO = 2) and the GTS of each device 1, 2, 3, 4, 5, 6, And the power consumption in each device when a slot is allocated when the slot is SO = 2.

Referring to FIG. 9, the smart home device 940 using the non-beacon mode can transmit all the devices (1,2,3,4,5,6,7) regardless of increasing beacon frame order ) Consumes the same high power (about 60 mW). A smart home device 930 using a beacon mode in accordance with the IEEE 802.15.4 communication standard may be configured to have a power consumption upper bound 920 and a power consumption lower bound 910 of the device according to the embodiment of the present disclosure. Consumes higher power consumption.

That is, according to one embodiment of the present disclosure, even if the beacon frame order is increased, the active period of the superframe can be increased by allocating the GTS slot length corresponding to the value of the superframe order 2 optimal for the 95 bytes size. In addition, the terminal device 100 can reduce the power consumed by the beacon mode devices 930 than conventional beacon mode devices 930 by controlling the communication section on / off according to the data transmission / reception mode in the allocated GTS.

10 is a simplified block diagram of a hub device and a terminal device according to an embodiment of the present disclosure; The block diagram shown in FIG. 10 is only an example and other block diagrams may be added.

10, the terminal device 100 may include at least one of a communication unit 110, a processor 120, and a functional unit 130. [ The terminal device 100 may be various devices that communicate with the hub device 200 on a wireless network, including various sensors.

The communication unit 110 receives the beacon message from the hub device 200 and transmits the GTS request message to the hub device 200 and transmits the GTS request message to the hub device 200 in the GTS time slot allocated by the processor 120. [ And data can be transmitted and received. The communication unit 110 may include at least one wireless communication chip capable of short-range wireless communication such as Wi-Fi, Bluetooth, and NFC. In one embodiment of the present invention, IEEE 802.15.4 wireless communication is used, but this is merely an embodiment, and the present invention can be applied to other wireless communication chips and implemented.

The functional unit 130 may perform a function corresponding to the type of the terminal device 100. [ For example, various functions that the terminal device 100 can perform in a smart home wireless network in the Internet of Things (IoT) environment. For example, the terminal device 100 including a sensor capable of detecting water leakage may include a function of detecting water and informing a user of the water. As another example, if the terminal device 100 includes a sensor that controls the lamp, it may include the ability to automatically turn the lamp on and off or adjust the amount of light in the lamp in certain circumstances. However, if the terminal device 100 is implemented as another device, the function unit 130 may perform a corresponding function according to the type of the implemented device. In addition, the implemented wireless network environment may be a network environment based on various types of IoT technologies such as hospitals, factories, offices, and the like.

The processor 120 transmits a GTS (Guaranteed Time Slot) allocation request including the data size information of the device to be transmitted to the hub device 200 to the hub device 200 through the communication unit 110, Receiving mode of the device 100 based on the received GTS allocation information, and transmits / receives data to / from the hub device 200 based on the determined transmission / reception mode The communication unit 110 can be controlled.

If the data size is less than the first value, the GTS allocation request is included in the first data size field having a length of 4 bits. If the data size is equal to or larger than the first value, Field, and the data size field may indicate size information of data to be transmitted to the hub device 200. [

The processor 130 determines that the transmission / reception mode is the first mode when data is received from the hub device 200 in the GTS interval allocated and allocated to the GTS, The receiver 110 may control the communication unit 110 to turn on the Receive and turn off the TX of the communication unit 110.

The processor 130 determines that the transmission / reception mode is the second mode when data is transmitted to the hub device 200 in the GTS interval allocated and allocated to the GTS, The communication unit 110 can be controlled so that the communication unit 110 is turned off and the TX unit of the communication unit 110 is turned on.

The hub device 200 may include a communication unit 210 and a processor 220.

The communication unit 210 can receive the GTS request message from the terminal device 100 and can perform data communication with the terminal device 100. [ The communication unit 210 may include at least one wireless communication chip capable of short-range wireless communication such as Wi-Fi, Bluetooth, and NFC. In one embodiment of the present invention, IEEE 802.15.4 wireless communication is used, but this is merely an embodiment, and the present invention can be applied to other wireless communication chips and implemented.

The processor 220 receives a GTS (Guaranteed Time Slot) allocation request including size information of data to be transmitted by the device 100 from each of the plurality of devices (or at least one device) It is possible to determine a superframe order (SO) for a plurality of devices based on the size information of one data, and allocate GTSs corresponding to the determined superframe order to GTSs of a plurality of devices.

When at least one of the GTS allocation requests received from the plurality of devices includes a GTS deallocation request, the processor 220 performs GTS deallocation in response to the GTS deallocation request, Lt; RTI ID = 0.0 &gt; time slot &lt; / RTI &gt;

When the time slot allocated among the GTSs is equal to or less than the predetermined number, the processor 220 determines each data arrival time required for data to be transmitted by the plurality of devices to arrive at the hub 200 based on the data size information It can be judged.

The processor 220 may perform GTS allocation for a device that includes data size information among a plurality of devices if the data arrival time is less than or equal to the total time of unallocated time slots of the GTS.

The processor 220 may determine a data arrival time using data size information, a GTS allocation delay time, the GTS request arrival time, and a packet generation rate of data from the device.

The processor 220 can determine the superframe order for a plurality of devices using the power consumption efficiency, the allocation delay efficiency, the bandwidth utilization efficiency, and the throughput efficiency of the hub device 200. [

The processor 220 may transmit to the plurality of devices via the communication unit 210 a beacon including a superframe for super frame order and GTS allocation information allocated to each of the plurality of devices.

The terminal device 100 and the hub device 200 may each include a memory (not shown), and the memory may include a program having various functions for controlling the terminal device 100 and the hub device 200 And data.

Embodiments in accordance with the present disclosure may also be embodied as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of computer-readable recording media include read-only memory (ROM), random access memory (RAM), CD-ROM, magnetic tape, floppy disk, optical data storage device. The computer readable recording medium may be distributed over a networked computer system such that the computer readable code is stored and executed in a distributed manner. In addition, one embodiment may be recorded as a computer program transmitted over a computer-readable transmission medium, such as a carrier wave, and received and implemented by a general purpose or special purpose digital computer executing the program. Also, in the embodiments, one or more units of the apparatuses and devices described above may include circuits, processors, microprocessors, and the like, which may execute computer programs stored on a computer- .

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes and modifications may be made by those skilled in the art without departing from the spirit and scope of the present invention.

100: device, terminal device
200: hub device, coordinator
510: GTS Characteristics
520: 4-bit data size field
530: 2-bit data size field

Claims (20)

A data communication method of a hub apparatus constituting a wireless communication system,
Receiving a Guaranteed Time Slot (GTS) allocation request including size information of data to be transmitted from each of a plurality of devices to a hub device;
Determining a superframe order (SO) for the plurality of devices based on size information of data received from each of the plurality of devices; And
And allocating a GTS corresponding to the determined superframe order to a GTS of the plurality of devices. The method according to claim 1,
Wherein the assigning comprises:
When a GTS deallocation request is included in at least one of the GTS allocation requests received from the plurality of devices, performing GTS deallocation corresponding to the GTS deallocation request, The method comprising: The method according to claim 1,
Wherein the determining step comprises:
Determining each data arrival time required for the data to be transmitted by the plurality of devices to arrive at the hub device based on the size information of the data when the time slots allocated among the GTSs are equal to or less than a predetermined number Methods of inclusion. The method of claim 3,
Wherein the assigning comprises:
And performing GTS allocation for a device including the data size information among the plurality of devices if the data arrival time is less than or equal to a total time of unallocated time slots of the GTS. The method of claim 3,
Wherein the step of determining the arrival time comprises:
And determining the data arrival time using the data size information, the GTS allocation delay time, the GTS request arrival time, and the packet generation rate of the data from the device. The method according to claim 1,
Wherein the determining step comprises:
Wherein the superframe order for the plurality of devices is determined using power consumption efficiency, allocation delay efficiency, bandwidth utilization efficiency, and throughput efficiency of the hub device. The method according to claim 1,
The GTS allocation request is included in a first data size field having a length of 4 bits when the data size is less than a first value and is included in a second data size field having a length of 2 bits when the data size is equal to or larger than a first value, Size field, and the data size field indicates size information of data that the device desires to transmit to the hub device. The method according to claim 1,
And transmitting to the plurality of devices a beacon including a superframe for super frame order and GTS allocation information allocated to each of the plurality of devices. A hub apparatus constituting a wireless communication system,
A communication unit for transmitting and receiving data to and from a plurality of devices;
Receiving, from each of the plurality of devices, a GTS (Guaranteed Time Slot) allocation request including size information of a data that the device intends to transmit to the hub device; and, based on size information of data received from each of the plurality of devices, And a processor for determining a superframe order (SO) for a plurality of devices and allocating a GTS corresponding to the determined superframe order to a GTS of the plurality of devices. 10. The method of claim 9,
The processor comprising:
When a GTS deallocation request is included in at least one of the GTS allocation requests received from the plurality of devices, performing GTS deallocation corresponding to the GTS deallocation request, . 10. The method of claim 9,
The GTS allocation request is included in a first data size field having a length of 4 bits when the data size is less than a first value and is included in a second data size field having a length of 2 bits when the data size is equal to or larger than a first value, Size field, and the data size field indicates size information of data to be transmitted by the device. 10. The method of claim 9,
The processor comprising:
And determines a data arrival time required for the data to be transmitted by the plurality of devices to arrive at the hub device based on the size information of the data when the time slots allocated among the GTSs are equal to or less than a predetermined number. 13. The method of claim 12,
The processor comprising:
And performs GTS allocation for a device including the data size information among the plurality of devices when the data arrival time is less than or equal to a total time of unallocated time slots among the GTSs. 13. The method of claim 12,
The processor comprising:
And determines the data arrival time using the size information of the data, the GTS allocation delay time, the GTS request arrival time, and the packet generation rate of the data from the device. 13. The method of claim 12,
The processor comprising:
And determines a superframe order for the plurality of devices by using power consumption efficiency, allocation delay efficiency, bandwidth utilization efficiency, and throughput efficiency of the hub device. 11. The method of claim 10,
The processor comprising:
And transmits a beacon including a superframe for a superframe order to the plurality of devices via a communication unit, the GTS allocation information being allocated to each of the plurality of devices. A device for configuring a wireless network system,
A communication unit for transmitting and receiving data to and from the hub device;
(GTS) allocation request including data size information of a device to be transmitted to the hub device to the hub device, receives GTS allocation information for the device from the hub device, And a processor for controlling the communication unit to transmit / receive data to / from the hub device based on the determined transmission / reception mode. 18. The method of claim 17,
The GTS allocation request is included in a first data size field having a length of 4 bits when the data size is less than a first value and is included in a second data size field having a length of 2 bits when the data size is equal to or larger than a first value, Size field, and the data size field indicates size information of data to be transmitted to the hub device. 19. The method of claim 18,
The processor comprising:
Reception mode is determined to be the first mode and RX (Receive) of the communication unit is turned on during the allocated time slot of the GTS when the GTS is allocated and data is received from the hub device, And controls the communication unit to turn off TX (Transmit) of the communication unit. 19. The method of claim 18,
The processor comprising:
The transmission / reception mode is determined to be the second mode, the RX of the communication unit is turned off during the allocated time slot of the GTS, and the TX of the communication unit is turned off And controls the communication unit to turn on the communication unit.

Images