KR102541639B1 - Operation method of communication node in network supporting low power communication - Google Patents

Abstract

A method of operating a communication node in a network supporting low power communication is disclosed. The method of operating the device includes receiving a beacon including configuration information of a DL/UL slot in super frame #n from a reference node, based on the configuration information, location of a DL/UL slot configured in super frame #n and performing at least one of a downlink reception operation and an uplink transmission operation in the DL/UL slot. Accordingly, the performance of the communication system can be improved.

Description

Operation method of communication node in network supporting low power communication {OPERATION METHOD OF COMMUNICATION NODE IN NETWORK SUPPORTING LOW POWER COMMUNICATION}

The present invention relates to low-power communication technology, and more particularly, to a synchronization method for power saving and a data unit transmission method.

Along with the development of information and communication technology, various wireless communication technologies are being developed. Wireless communication technology is largely classified into wireless communication technology using a licensed band and wireless communication technology using an unlicensed band (eg, industrial scientific medical (ISM) band) according to the band used. It can be. Since the right to use a licensed band is exclusively given to one operator, a wireless communication technology using a licensed band can provide better reliability and communication quality than a wireless communication technology using an unlicensed band.

Representative wireless communication technologies using licensed bands include long term evolution (LTE), LTE-A (advanced), and new radio (NR) specified in the 3rd generation partnership project (3GPP) standard. Each base station and user equipment (UE) supporting the technology may transmit and receive signals through a licensed band. Representative wireless communication technologies using unlicensed bands include the wireless local area network (WLAN) specified in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard and the wireless personal area network (WPAN) specified in the IEEE 802.15 standard. Alternatively, a communication node supporting WPAN may transmit and receive signals through an unlicensed band.

Meanwhile, communication in an unlicensed band may be performed according to a frequency hopping method, and a frequency hopping pattern may be shared in advance by communication nodes. The communication node #1 must know the operating frequency band of the communication node #2 (eg, the current operating frequency band according to the frequency hopping pattern) in order to perform communication. In order to check the operating frequency band of the communication node #2, the communication node #1 may perform a channel monitoring operation, and power consumption may increase due to the channel monitoring operation.

In addition, a downlink (DL) slot for downlink communication and an uplink (UL) slot for uplink communication may be defined in an unlicensed band. Only downlink communication may be allowed in the DL slot, and only uplink communication may be allowed in the UL slot. Even when an uplink data unit is generated in a DL slot, the communication node cannot transmit the uplink data unit in the current DL slot, and transmission of the uplink data unit may be delayed until a UL slot after the DL slot. Due to this, power consumption of the communication node may increase.

An object of the present invention for solving the above problems is to provide a method and apparatus for signaling information indicating an operating frequency band of a communication node in a communication system.

In addition, an object of the present invention to solve the above problems is to provide a method and apparatus for transmitting a data unit in a slot allowing downlink communication and uplink communication in a communication system.

A method of operating a device according to a first embodiment of the present invention for achieving the above object includes receiving a beacon including configuration information of a DL/UL slot from a reference node in super frame #n, based on the configuration information checking the location of the DL/UL slot configured in the super frame #n, and performing at least one operation of a downlink reception operation and an uplink transmission operation in the DL/UL slot, wherein the Downlink communication and uplink communication are permitted in the DL/UL slot, and n is an integer greater than or equal to 0.

Here, the configuration information may include information indicating the start time of the DL/UL slot and information indicating the duration of the DL/UL slot.

Here, the configuration information may include information indicating a validity period of the DL/UL slot, and the DL/UL slot according to the configuration information is a super frame indicated by the validity period from the super frame #n. It may be set in each of the super frames up to #j, and j may be an integer greater than n.

Here, when a downlink data unit is not received in a preset period from the start of the DL/UL slot, the uplink transmission operation may be performed in the DL/UL slot.

Here, when a downlink data unit is not received in a preset period from the start of the DL/UL slot and there is no uplink data unit to be transmitted to the reference node, the device after the super frame #n It can operate in sleep mode until the beacon period within super frame #n+1 located there.

Here, the DL/UL slot may be configured within the CFP of the super frame #n.

Here, the operating method of the device may further include receiving, from the reference node, a DL bitmap indicating whether a downlink data unit is transmitted in the DL/UL slot, and the DL bitmap is the beacon or After receiving the beacon, it may be received through a separate message.

Here, when the DL bitmap indicates that the downlink data unit is not transmitted in the DL/UL slot, the uplink transmission operation may be performed in the DL/UL slot.

To achieve the above object, a method of operating a reference node according to a second embodiment of the present invention includes generating a beacon including configuration information of a DL/UL slot, transmitting the beacon in a beacon period within super frame #n and performing at least one of a downlink transmission operation and an uplink reception operation in the DL/UL slot indicated by the configuration information in the super frame #n, wherein the DL/UL Downlink communication and uplink communication are allowed in a slot, and n may be an integer greater than or equal to 0.

Here, the configuration information may include information indicating the start time of the DL/UL slot and information indicating the duration of the DL/UL slot.

Here, the configuration information may include information indicating a validity period of the DL/UL slot, and the DL/UL slot according to the configuration information is a super frame indicated by the validity period from the super frame #n. It may be set in each of the super frames up to #j, and j may be an integer greater than n.

Here, the DL/UL slot may be configured within the CFP of the super frame #n.

Here, the operating method of the reference node may further include transmitting a DL bitmap indicating whether to transmit a downlink data unit in the DL/UL slot, wherein the DL bitmap corresponds to the beacon or the beacon. After transmission, it may be transmitted through a separate message.

Here, the operating method of the reference node may further include transmitting a control signal including information indicating a frequency band in which the beacon is transmitted through a preset frequency band, wherein the control signal is the super frame # It may be transmitted after the beacon within n, and the preset frequency band may be different from the frequency band in which the beacon is transmitted.

A device according to a third embodiment of the present invention for achieving the above object includes a processor and a memory in which at least one command executed by the processor is stored, and the at least one command includes a frequency at which beacon #1 is transmitted. A control signal including information indicating band #k is received from a reference node through frequency band #m of super frame #n, and super frame #n+1 is based on the frequency band #k and a preset frequency hopping pattern. Estimates frequency band #p on which beacon #2 will be transmitted, and receives the beacon #2 including DL/UL slot configuration information from the reference node through the frequency band #p of the super frame #n+1 and checking the position of the DL / UL slot set in the super frame #n + 1 based on the configuration information, and performing at least one of a downlink reception operation and an uplink transmission operation in the DL / UL slot , wherein downlink communication and uplink communication are allowed in the DL/UL slot, n is an integer greater than or equal to 0, and each of k, m, and p is a different positive integer.

Here, the configuration information may include information indicating a start time of the DL/UL slot, information indicating a duration of the DL/UL slot, and information indicating a valid period of the DL/UL slot, The DL/UL slot according to the configuration information may be configured in each of super frames from super frame #n+1 to super frame #j indicated by the valid period, where j is greater than n+1. It can be a large integer.

Here, when a downlink data unit is not received in a preset period from the start of the DL/UL slot, the uplink transmission operation may be performed in the DL/UL slot.

Here, when a downlink data unit is not received in a preset period from the start of the DL/UL slot and there is no uplink data unit to be transmitted to the reference node, the device transmits the super frame #n+1 It can operate in sleep mode until the next beacon period in super frame #n+2 located thereafter.

Here, the at least one command may be further executed to receive, from the reference node, a DL bitmap indicating whether a downlink data unit is transmitted in the DL/UL slot, and the DL bitmap is the beacon #2 or the After receiving beacon #2, it may be received through a separate message.

Here, when the DL bitmap indicates that the downlink data unit is not transmitted in the DL/UL slot, the uplink transmission operation may be performed in the DL/UL slot.

According to the present invention, a reference node may transmit a beacon based on a frequency hopping pattern, and after transmission of the beacon, including information indicating a frequency band to which the beacon is currently transmitted The control signal may be transmitted through a preset frequency band. A device that is not synchronized with the reference node may perform a monitoring operation in a preset frequency band in order to receive a control signal. When a control signal is received in a preset frequency band, the device may check the frequency band where the beacon is transmitted based on the information included in the control signal, and start communication with the reference node based on the checked frequency band and frequency hopping pattern. can be done Therefore, since synchronization between the reference node and the device can be performed using a control signal instead of a beacon, power consumption in the device can be reduced.

Also, in the communication system, DL/UL slots allowing downlink communication and uplink communication may be configured. A device may perform a monitoring operation for reception of a downlink data unit in a preset period within a DL/UL slot. If the downlink data unit is not received in a preset period within the DL/UL slot, the device may transmit the uplink data unit in the DL/UL slot. Accordingly, the efficiency of resource use in the communication system can be improved, and thus the transmission delay of the data unit can be reduced.

1 is a conceptual diagram illustrating a first embodiment of a communication system.
2 is a block diagram showing a first embodiment of a communication node constituting a communication system.
3 is a block showing a first embodiment of a super frame in a communication system.
4 is a conceptual diagram illustrating a first embodiment of a frequency band in a communication system.
5 is a flow chart illustrating a first embodiment of a synchronization method in a communication system.
FIG. 6 is a conceptual diagram illustrating beacons and control signals transmitted according to the synchronization method shown in FIG. 5 .
7 is a block diagram illustrating a first embodiment of a control signal in a communication system.
8 is a flowchart illustrating a first embodiment of a downlink/uplink transmission method through a DL/UL slot in a communication system.
9 is a block diagram illustrating a first embodiment of a super frame including DL/UL slots in a communication system.

Since the present invention can make various changes and have various embodiments, specific embodiments are illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to specific embodiments, and should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. These terms are only used for the purpose of distinguishing one component from another. For example, a first element may be termed a second element, and similarly, a second element may be termed a first element, without departing from the scope of the present invention. The terms and/or include any combination of a plurality of related recited items or any of a plurality of related recited items.

It is understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, but other elements may exist in the middle. It should be. On the other hand, when an element is referred to as “directly connected” or “directly connected” to another element, it should be understood that no other element exists in the middle.

Terms used in this application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "include" or "have" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and unless explicitly defined in this application, they should not be interpreted in an ideal or excessively formal meaning. don't

Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in more detail. In order to facilitate overall understanding in the description of the present invention, the same reference numerals are used for the same components in the drawings, and redundant descriptions of the same components are omitted.

A communication system to which embodiments according to the present invention are applied will be described. A communication system to which embodiments according to the present invention are applied is not limited to the contents described below, and embodiments according to the present invention can be applied to various communication systems. Here, the communication system may be used in the same sense as a communication network.

1 is a conceptual diagram illustrating a first embodiment of a communication system.

Referring to FIG. 1 , a communication system 100 may include a plurality of communication nodes 110 , 121 , 122 , 123 , and 124 . The plurality of communication nodes 110, 121, 122, 123, and 124 may perform low-power communication in a licensed band or an unlicensed band. A plurality of communication nodes 110, 121, 122, 123, and 124 operating in a licensed band are narrowband (NB)-internet of things (IoT), cellular IoT (NB-CIoT), or long term evolution (LTE)- Machine type communication (MTC) may be supported. The plurality of communication nodes 110, 121, 122, 123, and 124 operating in the unlicensed band may support low power wide area network (LPWAN), SigFox, LoRa, or Ingenu. can The plurality of communication nodes 110, 121, 122, 123, and 124 operating in the unlicensed band may operate in a carrier-sense multiple access with collision avoidance (CSMA/CA) method. Each of the plurality of communication nodes 110, 121, 122, 123, and 124 may have the following structure.

2 is a block diagram showing a first embodiment of a communication node constituting a communication system.

Referring to FIG. 2 , a communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to a network to perform communication. In addition, the communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, and the like. Each component included in the communication node 200 may be connected by a bus 270 to communicate with each other.

However, each component included in the communication node 200 may be connected through an individual interface or an individual bus centered on the processor 210 instead of the common bus 270 . For example, the processor 210 may be connected to at least one of the memory 220, the transmission/reception device 230, the input interface device 240, the output interface device 250, and the storage device 260 through a dedicated interface. .

The processor 210 may execute a program command stored in at least one of the memory 220 and the storage device 260 . The processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods according to embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may include at least one of a volatile storage medium and a non-volatile storage medium. For example, the memory 220 may include at least one of a read only memory (ROM) and a random access memory (RAM).

Referring back to FIG. 1 , a plurality of communication nodes 110 , 121 , 122 , 123 , and 124 operating in an unlicensed band may perform communication using a super frame. A super frame can be set as follows.

3 is a block showing a first embodiment of a super frame in a communication system.

Referring to FIG. 3 , super frames may be consecutive on the time axis. Each of the super frames #0 to 4 may include a beacon period, an active period, and an inactive period. The active period may include a contention access period (CAP) and a contention free period (CFP).

The reference node 110 shown in FIG. 1 may transmit beacons in the beacon period of super frames #0 to 4. The beacon transmission period may be set in units of super frames. For example, when the beacon transmission period is one super frame, the beacon may be transmitted every super frame. If the beacon transmission period is two super frames, the beacon may be transmitted in super frames #0, #2, #4, and the like.

The beacon may be transmitted in a broadcasting method and may include information necessary for communication (eg, a frequency band in which the beacon is transmitted, a frequency hopping pattern, a frequency hopping period, etc.) there is. The devices 121 to 124 shown in FIG. 1 may receive a beacon from the reference node 110 and may perform communication based on information included in the beacon. Communication between the plurality of communication nodes 110, 121, 122, 123, and 124 may be performed in each active period of super frames #0 to 4. Here, the reference node 110 may be referred to as an access point, a gateway, or a coordinator, and each of the devices 121 to 124 is an end-device, an end-node, Or it may be referred to as a station.

The plurality of communication nodes 110, 121, 122, 123, and 124 may operate according to a frequency hopping scheme. The frequency hopping pattern and period may be shared in advance by a plurality of communication nodes 110, 121, 122, 123, and 124. One super frame may be transmitted in the same frequency band, and the frequency band in which the super frame is transmitted may vary according to a preset frequency hopping pattern and period.

4 is a conceptual diagram illustrating a first embodiment of a frequency band in a communication system.

Referring to FIG. 4 , a plurality of communication nodes 110, 121, 122, 123, and 124 may perform communication in frequency bands #0 to n. n may be an integer of 2 or more, and m may be an integer of 2 or less. For example, if the frequency hopping pattern is {2, 0, n, n-2, m}, super frame #0 can be transmitted in frequency band #2, and super frame #1 can be transmitted in frequency band #0. super frame #2 can be transmitted in frequency band #n, super frame #3 can be transmitted in frequency band #n-2, and super frame #4 can be transmitted in frequency band #m .

In order to communicate with the reference node 110, the devices 121 to 124 need to know the frequency band over which the beacon is transmitted. To this end, the devices 121 to 124 may perform a monitoring operation in a specific frequency band in order to receive a beacon. When the beacon transmission period is long in a specific frequency band, the devices 121 to 124 must perform a monitoring operation for a long time. In this case, power consumption of the devices 121 to 124 may increase.

Meanwhile, a downlink (DL) slot for downlink communication and an uplink (UL) slot for uplink communication may be defined in the super frame. Only downlink communication may be allowed in the DL slot, and only uplink communication may be allowed in the UL slot. Even if an uplink data unit (unit) is generated in the DL slot, the devices 121 to 124 cannot transmit the uplink data unit in the current DL slot, and the transmission of the uplink data unit is delayed until the UL slot after the DL slot It can be. As a result, power consumption of the devices 121 to 124 may increase.

Next, operating methods of a communication node for power saving in a communication system will be described. Even when a method (for example, transmission or reception of a signal) performed in a first communication node among communication nodes is described, a second communication node corresponding thereto is described as a method performed in the first communication node and a method (eg, signal transmission or reception) For example, receiving or transmitting a signal) may be performed. That is, when an operation of a device is described, a reference node corresponding thereto may perform an operation corresponding to the operation of the device. Conversely, when the operation of the reference node is described, a device corresponding thereto may perform an operation corresponding to that of the reference node.

FIG. 5 is a flowchart illustrating a first embodiment of a synchronization method in a communication system, and FIG. 6 is a conceptual diagram illustrating beacons and control signals transmitted according to the synchronization method shown in FIG. 5 .

5 and 6, the communication system may include a reference node (ie, reference node 110 shown in FIG. 1) and a device (ie, devices 121 to 124 shown in FIG. 1), , each of the reference node and device may be configured identically or similarly to the communication node 200 shown in FIG. 2 . The reference node and device may operate according to a frequency hopping scheme, and frequency hopping information (eg, a frequency hopping pattern and period) may be previously shared by the reference node and device. Here, the frequency hopping pattern may be {2, 0, n, n-1, m}, and the frequency hopping period may be 5 super frames.

The reference node may transmit a beacon according to a frequency hopping pattern and period (S510). For example, the reference node can transmit a beacon on frequency band #2 in super frame #0, transmit a beacon on frequency band #0 in super frame #1, and transmit a beacon on frequency band #n in super frame #2. Beacons can be transmitted through In addition, the reference node may transmit a beacon through frequency band #n-1 in super frame #3 and transmit a beacon through frequency band #m in super frame #4. Here, each of n and m may be a positive integer.

In addition, the reference node may transmit a control signal in the super frame in which the beacon is transmitted after transmitting the beacon (S520). The control signal may be transmitted immediately after transmission of the beacon. Alternatively, the control signal may be transmitted after a guard period from the beacon transmission end point. For example, the control signal may be transmitted in a CAP, CFP, or inactive period within a super frame. When the control signal is transmitted through the CFP in the super frame, the first symbol of the CFP may be used for transmission of the control signal. The control signal may include information indicating a frequency band in which a beacon is transmitted in a super frame to which the control signal belongs. For example, the control signal may be configured as follows.

7 is a block diagram illustrating a first embodiment of a control signal in a communication system.

Referring to FIG. 7 , a control signal 700 may include a preamble 710 and a payload 720, and the payload 720 includes a channel field 721 and a reserved field 722. can do. The channel field 721 may include information indicating a frequency band in which a beacon is transmitted in a super frame to which the control signal 700 belongs. The reserved field 722 may include at least one of information indicating a center frequency, information indicating a coding rate, and a spreading factor.

Referring back to FIGS. 5 and 6 , the reference node may transmit a control signal in a preset frequency band. A preset frequency band may be shared by reference nodes and devices. When the preset frequency band is frequency band #m, the reference node may transmit a control signal in frequency band #m. For example, in super frame #0, the reference node may transmit a control signal through frequency band #m after transmitting a beacon through frequency band #2. The control signal transmitted through frequency band #m of super frame #0 may include information indicating frequency band #2 through which the beacon is transmitted.

In super frame #1, the reference node may transmit a control signal on frequency band #m after transmitting a beacon on frequency band #0. The control signal transmitted through frequency band #m of super frame #1 may include information indicating frequency band #0 through which the beacon is transmitted. In super frame #2, the reference node may transmit a control signal on frequency band #m after transmitting a beacon on frequency band #n. The control signal transmitted through frequency band #m of super frame #2 may include information indicating frequency band #n on which the beacon is transmitted.

In super frame #3, the reference node may transmit a control signal through frequency band #m after transmitting a beacon through frequency band #n-1. The control signal transmitted through frequency band #m of super frame #3 may include information indicating frequency band #n-1 in which the beacon is transmitted. In super frame #4, the reference node may transmit a control signal on frequency band #m after transmitting a beacon on frequency band #m. The control signal transmitted through frequency band #m of super frame #4 may include information indicating frequency band #m in which the beacon is transmitted. Alternatively, if the frequency band in which the control signal is transmitted within one super frame is the same as the frequency band in which the beacon is transmitted, transmission of the control signal may be omitted. That is, transmission of the control signal in super frame #4 may be omitted.

Meanwhile, a device that is not synchronized with the reference node may perform a monitoring operation in a preset frequency band (eg, frequency band #m) to receive a beacon or control signal. For example, when the monitoring operation is performed in frequency band #m of super frame #0, the device cannot receive a beacon but can receive a control signal. When the control signal is received from the reference node, the device may check the frequency band #2 to which the beacon is transmitted in super frame #0 based on the information included in the control signal. The device may predict the frequency band in which the beacon is transmitted in super frame #1 based on the frequency band #2 and the frequency hopping pattern in which the beacon is transmitted in super frame #0 (S530).

If the frequency hopping pattern is {2, 0, n, n-1, m}, the device can predict that the beacon is transmitted in frequency band #0 of super frame #1. Accordingly, the device may change the operating frequency band from frequency band #m to frequency band #0, and perform monitoring operation in frequency band #0 of super frame #1 (S540). In this case, the device may receive a beacon of the reference node in frequency band #0 of super frame #1 and check information included in the beacon. Also, the device may be synchronized to the reference node using information included in the beacon.

Meanwhile, when a device that is not synchronized with the reference node starts a monitoring operation in frequency band #m of super frame #4 to receive a beacon or control signal, the device may receive the beacon before the control signal. In this case, the device can check the information included in the beacon and can be synchronized with the reference node using the information included in the beacon.

8 is a flowchart illustrating a first embodiment of a downlink/uplink transmission method through a DL/UL slot in a communication system, and FIG. 9 is a first embodiment of a super frame including a DL/UL slot in a communication system. It is a block diagram showing

8 and 9, the communication system may include a reference node (ie, reference node 110 shown in FIG. 1) and a device (ie, devices 121 to 124 shown in FIG. 1), , each of the reference node and device may be configured identically or similarly to the communication node 200 shown in FIG. 2 . The reference node and device may operate according to a frequency hopping scheme, and frequency hopping information (eg, a frequency hopping pattern and period) may be previously shared by the reference node and device.

The reference node may configure DL/UL slots within the super frame (S810). DL/UL slots may be used for downlink transmission and uplink transmission. DL/UL slots may be set in CAPs, CFPs, or inactive intervals within a super frame. The reference node may transmit a beacon including DL/UL slot configuration information (S820). The configuration information of the DL/UL slot may include a start point (eg, start symbol index) of the DL/UL slot, a duration of the DL/UL slot, an effective period of the DL/UL slot, and a DL detection period. there is.

The duration of the DL/UL slot may indicate the length from the start of the DL/UL slot, and the effective period of the DL/UL slot may indicate the number of consecutive super frames in which the DL/UL slot exists. For example, when the effective period of a DL/UL slot indicated by a beacon frame transmitted through super frame #0 is three super frames, the DL/UL slots may be configured in super frames #0 to 3. The DL detection period may indicate a period in which a monitoring operation for reception of a downlink data unit is performed within a DL/UL slot. The DL detection interval may start from the start of the DL/UL slot and may be set shorter than the duration of the DL/UL slot.

Also, the reference node may transmit a DL bitmap indicating whether downlink transmission is performed in a DL/UL slot (S830). A DL bitmap may be included in a beacon. Alternatively, the DL bitmap may be transmitted through other messages than beacons. If the size of the DL bitmap is 1 bit, the DL bitmap set to "0" may indicate that downlink transmission is not performed in the DL/UL slot, and the DL bitmap set to "1" may indicate that DL/UL It may indicate that downlink transmission is performed in the slot. For example, when a DL bitmap set to “0” is transmitted in super frame #0, the corresponding DL bitmap may indicate that downlink transmission is not performed in a DL/UL slot in super frame #0. When a DL bitmap set to “1” is transmitted in super frame #2, the corresponding DL bitmap may indicate that downlink transmission is performed in a DL/UL slot in super frame #2.

Meanwhile, the device may receive a beacon from the reference node and check configuration information of a DL/UL slot included in the beacon. The device may perform at least one operation of a downlink communication operation and an uplink communication operation in a DL/UL slot (S840). For example, a device may perform a monitoring operation to receive a downlink data unit in a DL detection period in a DL/UL slot. When a downlink data unit is detected in the DL detection interval, the device may receive the downlink data unit in the DL/UL slot.

On the other hand, when the downlink data unit is not detected in the DL detection interval, the device having the uplink data unit may transmit the uplink data unit to the reference node in the remaining interval of the DL/UL slot. Alternatively, when the downlink data unit is not detected and the uplink data unit does not exist in the DL detection period, the device may operate in a sleep mode until the beacon period of the next super frame.

Meanwhile, when a DL bitmap as well as a DL/UL slot is received from the reference node, the device can check whether a downlink data unit is transmitted in the DL/UL slot based on the DL bitmap. If it is determined that the downlink data unit will be transmitted in the DL/UL slot, the device may perform a monitoring operation for receiving the downlink data unit in the DL/UL slot. On the other hand, if it is determined that no downlink data unit is transmitted in the DL/UL slot and there is an uplink data unit, the device may transmit the uplink data unit to the reference node in the DL/UL slot. Alternatively, when it is determined that the downlink data unit is not transmitted in the DL/UL slot and there is no uplink data unit, the device may operate in sleep mode until the beacon period of the next super frame.

The methods according to the present invention may be implemented in the form of program instructions that can be executed by various computer means and recorded on a computer readable medium. Computer readable media may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on a computer readable medium may be specially designed and configured for the present invention or may be known and usable to those skilled in computer software.

Examples of computer readable media include hardware devices specially configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter or the like as well as machine language codes generated by a compiler. The hardware device described above may be configured to operate with at least one software module to perform the operations of the present invention, and vice versa.

Although described with reference to the above embodiments, those skilled in the art will understand that the present invention can be variously modified and changed without departing from the spirit and scope of the present invention described in the claims below. You will be able to.

Claims (20)

As a method of operating a device in a communication system,
Receiving a beacon including configuration information of a DL/UL slot (downlink/uplink slot) from a reference node in a super frame #n;
checking a location of a DL/UL slot configured in the super frame #n based on the configuration information; and
Including performing at least one operation of a downlink reception operation and an uplink transmission operation in the DL / UL slot,
Downlink communication and uplink communication are allowed in the DL/UL slot, and n is an integer greater than or equal to 0;
When a downlink data unit is not received in a preset interval from the start of the DL/UL slot, the uplink transmission operation is performed in the DL/UL slot. The method of claim 1,
The configuration information includes information indicating the start time of the DL/UL slot and information indicating a duration of the DL/UL slot. The method of claim 1,
The configuration information includes information indicating a valid interval of the DL/UL slot, and the DL/UL slot according to the configuration information is from super frame #n to super frame #j indicated by the valid interval. It is set in each of the super frames, and the j is an integer greater than the n, the operating method of the device. delete The method of claim 1,
When the downlink data unit is not received in a preset interval from the start of the DL/UL slot and there is no uplink data unit to be transmitted to the reference node, the device after the super frame #n A method of operating a device operating in a sleep mode until a beacon period within super frame #n+1 located therein. The method of claim 1,
The DL / UL slot is set within a contention free period (CFP) of the super frame #n. The method of claim 1,
The method of operating the device,
Receiving from the reference node a DL bitmap indicating whether the downlink data unit is transmitted in the DL/UL slot;
The DL bitmap is received through the beacon or a separate message after receiving the beacon. The method of claim 7,
When the DL bitmap indicates that the downlink data unit is not transmitted in the DL/UL slot, the uplink transmission operation is performed in the DL/UL slot. As a method of operating a reference node in a communication system,
Generating a beacon including configuration information of a DL/UL slot (downlink/uplink slot);
Transmitting the beacon in a beacon period within a super frame #n;
transmitting a control signal including information indicating a frequency band in which the beacon is transmitted through a preset frequency band; and
Performing at least one of a downlink transmission operation and an uplink reception operation in the DL/UL slot indicated by the configuration information in the super frame #n,
Downlink communication and uplink communication are allowed in the DL/UL slot, and n is an integer greater than or equal to 0;
wherein the control signal is transmitted after the beacon within the super frame #n, and the preset frequency band is different from a frequency band in which the beacon is transmitted. The method of claim 9,
The configuration information includes information indicating a start time of the DL/UL slot and information indicating a duration of the DL/UL slot. The method of claim 9,
The configuration information includes information indicating a valid interval of the DL/UL slot, and the DL/UL slot according to the configuration information is from super frame #n to super frame #j indicated by the valid interval. It is set in each of the super frames, and the j is an integer greater than the n, the operating method of the reference node. The method of claim 9,
The DL/UL slot is set within a contention free period (CFP) of the super frame #n. The method of claim 9,
The operation method of the reference node,
Transmitting a DL bitmap indicating whether a downlink data unit is transmitted in the DL/UL slot,
The DL bitmap is transmitted through the beacon or a separate message after transmission of the beacon. delete As a device in a communication system,
processor; and
A memory in which at least one instruction executed by the processor is stored;
The at least one command,
Receiving a control signal including information indicating frequency band #k on which beacon #1 is transmitted from a reference node through frequency band #m of super frame #n;
estimating frequency band #p on which beacon #2 is to be transmitted in super frame #n+1 based on the frequency band #k and a preset frequency hopping pattern;
receiving the beacon #2 including configuration information of a DL/UL slot (downlink/uplink slot) from the reference node through the frequency band #p of the super frame #n+1;
confirming a location of a DL/UL slot configured in the super frame #n+1 based on the configuration information; and
Executed to perform at least one operation of a downlink reception operation and an uplink transmission operation in the DL / UL slot;
Downlink communication and uplink communication are allowed in the DL/UL slot, n is an integer greater than or equal to 0, and each of k, m, and p is a different positive integer,
When a downlink data unit is not received in a preset interval from the start of the DL/UL slot, the uplink transmission operation is performed in the DL/UL slot. The method of claim 15
The configuration information includes information indicating the start time of the DL/UL slot, information indicating a duration of the DL/UL slot, and information indicating a valid period of the DL/UL slot,
The DL/UL slot according to the configuration information is configured in each of super frames from super frame #n+1 to super frame #j indicated by the valid period, where j is an integer greater than n+1 , device. delete The method of claim 15
When the downlink data unit is not received in a preset interval from the start of the DL/UL slot and there is no uplink data unit to be transmitted to the reference node, the device determines the super frame #n+1 A device that operates in sleep mode until the beacon period in super frame #n+2 located thereafter. The method of claim 15
The at least one command,
It is further executed to receive a DL bitmap indicating whether the downlink data unit is transmitted in the DL/UL slot from the reference node;
The DL bitmap is received through a separate message after receiving the beacon #2 or the beacon #2. The method of claim 19
When the DL bitmap indicates that the downlink data unit is not transmitted in the DL/UL slot, the uplink transmission operation is performed in the DL/UL slot.

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