KR20190067094A - Operation method of communication node in network supporting low power communication - Google Patents

Abstract

Disclosed is an operation method of a communication node in a network supporting low power communication. According to the present invention, an operation method of a device comprises the steps of: receiving beacon including configuration information of a downlink (DL) / uplink (UL) slot in a super frame #n; confirming a location of the DL / UL slot set in the super frame #n 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. Accordingly, the performance of the communication system may be improved.

Description

TECHNICAL FIELD [0001] The present invention relates to a method of operating a communication node in a network supporting low-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-power communication technology, and more particularly, to a synchronization method for power saving and a transmission method of a data unit.

With the development of information and communication technology, various wireless communication technologies are being developed. Wireless communication technologies are broadly classified into wireless communication technologies using a licensed band and wireless communication technologies using an unlicensed band (for example, an industrial scientific medical (ISM) band) . Since licenses are licensed exclusively to one operator, wireless communication technologies that use licensed bands can provide better reliability and better communication quality than wireless licensed technologies that use license-exempt bands.

(Long term evolution), LTE-A (advanced), and NR (new radio) defined in the 3rd generation partnership project (3GPP) standard are typical wireless communication technologies using licensed bands. Each of the base stations and user equipment (UE) supporting the technology can transmit and receive signals through the license band. A wireless local area network (WLAN) specified in the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, a wireless personal area network (WPAN) specified in the IEEE 802.15 standard, and the like, Or a WPAN-capable communication node may send and receive signals via the license-exempt band.

On the other hand, in the license-exempt band, communication can be performed according to a frequency hopping scheme, and a frequency hopping pattern can be pre-shared at communication nodes. The communication node # 1 must know the operating frequency band of the communication node # 2 (for example, the current operating frequency band according to the frequency hopping pattern) in order to perform communication. In order to confirm the operating frequency band of the communication node # 2, the communication node # 1 can perform the monitoring operation of the channel, and power consumption may increase due to the monitoring operation of the channel.

Also, a downlink (DL) slot for downlink communication and an uplink (UL) slot for uplink communication can be defined in the license-exempt band. Only downlink communication in the DL slot may be allowed and only uplink communication in the UL slot may be allowed. Even if an uplink data unit occurs in the DL slot, the communication node can not transmit the uplink data unit in the current DL slot, and the transmission of the uplink data unit can be delayed to the UL slot after the DL slot. As a result, the power consumption of the communication node may increase.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and apparatus for signaling information indicating an operating frequency band of a communication node in a communication system.

It is another object of the present invention to provide a method and apparatus for transmitting a data unit in a slot where downlink communication and uplink communication are allowed in a communication system.

According to another aspect of the present invention, there is provided a method of operating a device, comprising: receiving a beacon including DL / UL slot setting information from a reference node in a super frame #n; Confirming a position of a DL / UL slot set in the super frame #n, and performing at least one of a downlink reception operation and an uplink transmission operation in the DL / UL slot, DL / UL slots allow downlink communication and uplink communication, and n is an integer of 0 or more.

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

Herein, the setting information may include information indicating a valid period of the DL / UL slot, and the DL / UL slot according to the setting information may include a superframe indicated by the valid period from the superframe #n, j may be set in each of superframes up to #j, and j may be an integer greater than n.

Herein, if the downlink data unit is not received in a predetermined interval from the start time of the DL / UL slot, the uplink transmission operation may be performed in the DL / UL slot.

Herein, if a downlink data unit is not received in a predetermined interval from the start time of the DL / UL slot and there is no uplink data unit to be transmitted to the reference node, And can operate in the sleep mode before the beacon period in the superframe # n + 1 located.

Here, the DL / UL slot may be set in the CFP of the superframe #n.

Here, the operation method of the device may further include receiving a DL bitmap indicating whether the DL data unit is transmitted in the DL / UL slot from the reference node, And may be received via a separate message after receiving the beacon.

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

According to another aspect of the present invention, there is provided a method of operating a reference node, the method including generating a beacon including setting information of a DL / UL slot, transmitting the beacon from a beacon period in the super frame # And performing at least one of a downlink transmission operation and an uplink reception operation in the DL / UL slot indicated by the setting information in the super frame #n, The downlink communication and the uplink communication are allowed in the slot, and n may be an integer equal to or greater than zero.

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

Herein, the setting information may include information indicating a valid period of the DL / UL slot, and the DL / UL slot according to the setting information may include a superframe indicated by the valid period from the superframe #n, j may be set in each of superframes up to #j, and j may be an integer greater than n.

Here, the DL / UL slot may be set in the CFP of the superframe #n.

Here, the method of operating the reference node may further include transmitting a DL bitmap indicating whether the DL data unit is transmitted in the DL / UL slot, and the DL bitmap may be transmitted to the beacon or the beacon And may be transmitted through a separate message after transmission.

The operation method of the reference node may further include transmitting a control signal including information indicating a frequency band to which the beacon is transmitted through a predetermined frequency band, n, and the predetermined frequency band may be different from the frequency band in which the beacon is transmitted.

According to a third aspect of the present invention there is provided a device comprising a processor and a memory in which at least one instruction executed by the processor is stored, From the reference node through the frequency band #m of the superframe #n and transmits a control signal including information indicating the band #k to the superframe # n + 1 based on the frequency band #k and the predetermined frequency hopping pattern Estimates the frequency band #p in which the beacon # 2 is to be transmitted, and receives the beacon # 2 including the DL / UL slot setting information from the reference node through the frequency band #p of the super frame # n + 1 And confirms the position of the DL / UL slot set in the super frame # n + 1 based on the setting information, And m is an integer equal to or greater than 0, and k, m, and p are each an integer equal to or greater than 0, and wherein, in the DL / UL slot, the downlink communication and the uplink communication are allowed, Are different positive integers.

Here, the setting information may include information indicating a starting time point 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 setting information may be set in each of the superframes from the superframe # n + 1 to the superframe #j indicated by the validity interval, It can be a large integer.

Herein, if the downlink data unit is not received in a predetermined interval from the start time of the DL / UL slot, the uplink transmission operation may be performed in the DL / UL slot.

If no downlink data unit is received in a predetermined interval from the start time of the DL / UL slot and there is no uplink data unit to be transmitted to the reference node, the device transmits the superframe # n + 1 And can operate in the sleep mode before the beacon period in the superframe # n + 2 located thereafter.

Here, the at least one command may be further executed to receive a DL bitmap indicating whether a DL data unit is transmitted in the DL / UL slot from the reference node, and the DL bitmap may be transmitted to the beacon # May be received via a separate message after receipt of beacon # 2.

Herein, if the DL bitmap indicates that the DL 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 may include information indicating the frequency band in which the current beacon is transmitted after transmission of the beacon The control signal can be transmitted through a predetermined frequency band. A device that is not synchronized with the reference node may perform a monitoring operation in a preset frequency band to receive the control signal. When a control signal is received in a preset frequency band, the device can confirm the frequency band in which the beacon was transmitted based on the information contained in the control signal, and communicate with the reference node based on the identified frequency band and frequency hopping pattern. Can be performed. Therefore, the synchronization between the reference node and the device can be performed using the control signal instead of the beacon, so that power consumption in the device can be reduced.

Also, a DL / UL slot in which downlink communication and uplink communication are allowed in the communication system can be established. The device may perform a monitoring operation for reception of a downlink data unit in a predetermined interval in a DL / UL slot. If a downlink data unit is not received in a predetermined interval in the DL / UL slot, the device can transmit the uplink data unit in the DL / UL slot. Therefore, 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 showing 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 diagram showing a first embodiment of a super frame in a communication system.
4 is a conceptual diagram showing 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.
6 is a conceptual diagram illustrating beacons and control signals transmitted according to the synchronization method shown in FIG.
7 is a block diagram showing 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 superframe including DL / UL slots in a communication system.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. may be used to describe various components, but the components 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. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be 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, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

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 this 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 relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

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

1 is a conceptual diagram showing 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, 124. The plurality of communication nodes 110, 121, 122, 123, and 124 may perform low power communication in a license band or a license-exempt band. The plurality of communication nodes 110, 121, 122, 123 and 124 operating in the licensed band may be a narrowband-Internet (I-T), a cellular terminated (NB-CIoT) MTC (machine type communication) can be supported. The plurality of communication nodes 110, 121, 122, 123 and 124 operating in the license-exempt band may support a low power wide area network (LPWAN), SigFox, LoRa, or Ingenu . The plurality of communication nodes 110, 121, 122, 123, and 124 operating in the license-exempt band may operate in a carrier-sense multiple access with collision avoidance (CSMA / CA) scheme. 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, the communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 connected to the network to perform communication. 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 and communicate with each other.

However, each component included in the communication node 200 may not be connected to the common bus 270 but may be connected to the processor 210 via an individual interface or a separate bus. For example, the processor 210 may be coupled to at least one of the memory 220, the transceiver 230, the input interface 240, the output interface 250 and the storage 260 via 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 in accordance with embodiments of the present invention are performed. Each of the memory 220 and the storage device 260 may be constituted of at least one of a volatile storage medium and a nonvolatile storage medium. For example, the memory 220 may comprise at least one of read-only memory (ROM) and random access memory (RAM).

Referring again to FIG. 1, a plurality of communication nodes 110, 121, 122, 123, and 124 operating in a license-exempt band can perform communication using a super frame. The superframe can be set as follows.

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

Referring to FIG. 3, the superframes may be continuous on the time axis. Each of the superframes # 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 can transmit beacons in the beacon period of the superframes # 0 to # 4. The beacon transmission period can be set in superframe units. For example, if the transmission period of the beacon is one superframe, the beacon can be transmitted every superframe. If the transmission period of the beacon is two superframes, the beacon can be transmitted in the superframe # 0, # 2, # 4, and the like.

The beacon may be transmitted in a broadcasting manner and may include information necessary for communication (e.g., a frequency band in which a beacon is transmitted, a frequency hopping pattern, a frequency hopping period, etc.) have. The devices 121 to 124 shown in FIG. 1 can receive a beacon from the reference node 110 and can perform communication based on the information included in the beacon. Communication between the plurality of communication nodes 110, 121, 122, 123, and 124 may be performed in an active period of each of the superframes # 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 may be referred to as an end-device, an end-node, Or < / RTI > 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 pre-shared at a plurality of communication nodes 110, 121, 122, 123, One superframe can be transmitted in the same frequency band, and a frequency band in which the superframe is transmitted according to a predetermined frequency hopping pattern and period can be changed.

4 is a conceptual diagram showing 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, when the frequency hopping pattern is {2, 0, n, n-2, m}, superframe # 0 may be transmitted in frequency band # 2, superframe # 1 may be transmitted in frequency band # , Superframe # 2 can be transmitted in frequency band #n, superframe # 3 can be transmitted in frequency band # n-2, and superframe # 4 can be transmitted in frequency band #m .

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

Meanwhile, DL (downlink) slots for downlink communication and UL (uplink) slots for uplink communication can be defined in a super frame. Only downlink communication in the DL slot may be allowed and only uplink communication in the UL slot may be allowed. Even if an uplink data unit occurs in the DL slot, the devices 121 to 124 can not 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 . As a result, the power consumption of the devices 121 to 124 may increase.

Next, methods of operating the communication node for power saving in the communication system will be described. Even if a method (e.g., transmission or reception of a signal) to be performed at the first communication node among the communication nodes is described, the corresponding second communication node is controlled by a method corresponding to the method performed at the first communication node For example, receiving or transmitting a signal). That is, when the operation of the device is described, the corresponding reference node can perform an operation corresponding to the operation of the device. Conversely, when the operation of the reference node is described, the corresponding device can perform the operation corresponding to the operation of the reference node.

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

5 and 6, a communication system may include a reference node (i.e., reference node 110 shown in FIG. 1) and a device (i.e., devices 121-124 shown in FIG. 1) Each of the reference node and the device may be configured to be the same as or similar to the communication node 200 shown in Fig. Reference nodes and devices may operate in accordance with a frequency hopping scheme, and frequency hopping information (e.g., frequency hopping patterns and periods) may be pre-shared at reference nodes and devices. Here, the frequency hopping pattern may be {2, 0, n, n-1, m}, and the frequency hopping period may be five super frames.

The reference node may transmit a beacon according to the frequency hopping pattern and the period (S510). For example, the reference node may transmit beacons in frequency band # 2 in superframe # 0, beacons in frequency band # 0 in superframe # 1, beacons in frequency band # Lt; RTI ID = 0.0 > beacon < / RTI > In addition, the reference node can transmit beacons in frequency band # n-1 in superframe # 3, and beacons in frequency band #m in superframe # 4. Here, each of n and m may be a positive integer.

In addition, after transmitting the beacon, the reference node may transmit the control signal in the superframe in which the beacon is transmitted (S520). The control signal may be transmitted immediately after transmission of the beacon. Alternatively, the control signal may be transmitted after a guard interval from the transmission end point of the beacon. For example, the control signal may be sent in the CAP, CFP, or inactive section within the superframe. When the control signal is transmitted via the CFP in the superframe, 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 the beacon is transmitted in the superframe to which the control signal belongs. For example, the control signal may be configured as follows.

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

7, the control signal 700 may include a preamble 710 and a payload 720 and the payload 720 may include a channel field 721 and a reserved field 722 can do. The channel field 721 may include information indicating a frequency band in which the beacon is transmitted in the superframe 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 again to FIGS. 5 and 6, the reference node may transmit a control signal in a predetermined frequency band. The preset frequency band can be shared by the reference node and the device. When the preset frequency band is the frequency band #m, the reference node can transmit the control signal in the frequency band #m. For example, in superframe # 0, the reference node may transmit the beacon through frequency band # 2 and then the control signal through frequency band #m. The control signal transmitted through the frequency band #m of the superframe # 0 may include information indicating the frequency band # 2 to which the beacon is transmitted.

In superframe # 1, the reference node may transmit the beacon through frequency band # 0 and then the control signal through frequency band #m. The control signal transmitted through the frequency band #m of the superframe # 1 may include information indicating the frequency band # 0 to which the beacon is transmitted. In superframe # 2, the reference node may transmit the beacon through the frequency band #n and then the control signal through the frequency band #m. The control signal transmitted through the frequency band #m of the superframe # 2 may include information indicating the frequency band #n to which the beacon is transmitted.

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

Meanwhile, a device that is not synchronized with the reference node may perform a monitoring operation in a predetermined frequency band (e.g., frequency band #m) to receive a beacon or a control signal. For example, when the monitoring operation is performed in the frequency band #m of the superframe # 0, the device can not receive the beacon but can receive the control signal. When the control signal is received from the reference node, the device can identify the frequency band # 2 in which the beacon was transmitted in superframe # 0 based on the information contained in the control signal. The device can predict the frequency band in which the beacon is transmitted in the superframe # 1 based on the frequency hopping pattern and the frequency band # 2 in which the beacon is transmitted in the superframe # 0 (S530).

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

On the other hand, when the device not synchronized with the reference node starts the monitoring operation in the frequency band #m of the superframe # 4 to receive the beacon or the control signal, the device can receive beacon first than the control signal. In this case, the device can identify the information contained in the beacon and be synchronized to the reference node using the information contained in the beacon.

FIG. 8 is a flowchart showing a first embodiment of a downlink / uplink transmission method through a DL / UL slot in a communication system, FIG. 9 is a flowchart illustrating a first embodiment of a superframe including DL / UL slots in a communication system Fig.

8 and 9, the communication system may include a reference node (i.e., reference node 110 shown in FIG. 1) and a device (i.e., devices 121-124 shown in FIG. 1) Each of the reference node and the device may be configured to be the same as or similar to the communication node 200 shown in Fig. Reference nodes and devices may operate in accordance with a frequency hopping scheme, and frequency hopping information (e.g., frequency hopping patterns and periods) may be pre-shared at reference nodes and devices.

The reference node may set DL / UL slots within the superframe (S810). The DL / UL slot can be used for downlink transmission and uplink transmission. The DL / UL slot may be set within the CAP, CFP, or inactive section within the superframe. The reference node may transmit a beacon including setting information of the DL / UL slot (S820). The setting information of the DL / UL slot may include a starting point (e.g., a starting symbol index) of the DL / UL slot, a duration of the DL / UL slot, a valid interval of the DL / UL slot, have.

The duration of the DL / UL slot may indicate the length from the beginning of the DL / UL slot, and the valid interval of the DL / UL slot may indicate the number of consecutive superframes in which the DL / UL slot is present. For example, if the valid period of the DL / UL slot indicated by the beacon frame transmitted through the superframe # 0 is three superframes, the DL / UL slot can be set in the superframes # 0 to 3. The DL detection interval may indicate a period during which a monitoring operation for receiving a downlink data unit is performed within a DL / UL slot. The DL detection interval may start from the starting point of the DL / UL slot and may be set shorter than the duration of the DL / UL slot.

In addition, the reference node may transmit a DL bitmap indicating whether downlink transmission is performed in the DL / UL slot (S830). The DL bitmap may be included in a beacon. Alternatively, the DL bitmap may be transmitted via a message other than a beacon. When the size of the DL bitmap is 1 bit, the DL bitmap set to "0 " can indicate that downlink transmission is not performed in the DL / UL slot and the DL bitmap set to & Slot to perform downlink transmission. For example, when a DL bitmap set to '0' in the superframe # 0 is transmitted, the corresponding DL bitmap may indicate that downlink transmission is not performed in the DL / UL slot in the superframe # 0. When a DL bitmap set to "1" in the superframe # 2 is transmitted, the corresponding DL bitmap can indicate that downlink transmission is performed in the DL / UL slot in the superframe # 2.

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

On the other hand, if the downlink data unit is not detected in the DL detection period, the device having the uplink data unit can transmit the uplink data unit to the reference node in the remaining period of the DL / UL slot. Alternatively, if a downlink data unit is not detected in the DL detection interval and there is no uplink data unit, the device may operate in a sleep mode until the beacon interval of the next superframe.

On the other hand, when the DL bitmap as well as the DL / UL slot are received from the reference node, the device can confirm whether the DL data unit is transmitted in the DL / UL slot based on the DL bitmap. If it is determined that the DL data unit is to be transmitted in the DL / UL slot, the device may perform a monitoring operation to receive the DL data unit in the DL / UL slot. On the other hand, when it is determined that the downlink data unit is not transmitted in the DL / UL slot and the uplink data unit exists, the device can transmit the uplink data unit to the reference node in the DL / UL slot. Alternatively, if it is determined that the downlink data unit is not transmitted in the DL / UL slot and the uplink data unit is not present, the device can operate in the sleep mode until the beacon period of the next superframe.

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer readable medium. The computer readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the computer readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software.

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

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined in the appended claims. It will be possible.

Claims (20)

A method of operating a device in a communication system,
Receiving from a reference node a beacon including configuration information of a downlink / uplink slot in a superframe #n;
Confirming a position of a DL / UL slot set in the super frame #n based on the setting 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, and n is an integer equal to or greater than zero. The method according to claim 1,
Wherein the setting information includes information indicating a starting time point of the DL / UL slot and information indicating a duration of the DL / UL slot. The method according to claim 1,
Wherein the setting information includes information indicating a valid period of the DL / UL slot, and the DL / UL slot according to the setting information includes information indicating a period from the superframe #n to the superframe #j indicated by the valid period Superframes, where j is an integer greater than n. The method according to claim 1,
Wherein the uplink transmission operation is performed in the DL / UL slot when a downlink data unit is not received in a predetermined interval from a start time of the DL / UL slot. The method according to claim 1,
If a downlink data unit is not received in a predetermined interval from the start time of the DL / UL slot and there is no uplink data unit to be transmitted to the reference node, And operates in a sleep mode until a beacon period in frame # n + 1. The method according to claim 1,
Wherein the DL / UL slot is set within a contention free period (CFP) of the superframe #n. The method according to claim 1,
A method of operating a device,
Further comprising receiving from the reference node a DL bitmap indicating whether to transmit a DL data unit in the DL / UL slot,
Wherein the DL bitmap is received via a separate message after receipt of the beacon or beacon. The method of claim 7,
Wherein the uplink transmission operation is performed in the DL / UL slot when the DL bitmap indicates that the downlink data unit is not transmitted in the DL / UL slot. A method of operating a reference node in a communication system,
Generating a beacon including setting information of a DL / UL slot (downlink / uplink slot);
Transmitting the beacon in a beacon period in a superframe #n; And
And performing at least one of a downlink transmission operation and an uplink reception operation in the DL / UL slot indicated by the setting information in the super frame #n,
Wherein DL and UL slots allow downlink and uplink communications, and n is an integer greater than or equal to zero. The method of claim 9,
Wherein the setting information includes information indicating a start time point of the DL / UL slot and information indicating a duration of the DL / UL slot. The method of claim 9,
Wherein the setting information includes information indicating a valid period of the DL / UL slot, and the DL / UL slot according to the setting information includes information indicating a period from the superframe #n to the superframe #j indicated by the valid period Superframes, where j is an integer greater than the n. The method of claim 9,
Wherein the DL / UL slot is set within a contention free period (CFP) of the superframe #n. The method of claim 9,
The method of operation of the reference node comprises:
Further comprising transmitting a DL bitmap indicating whether the DL data unit is transmitted in the DL / UL slot,
Wherein the DL bitmap is transmitted via a separate message after transmission of the beacon or the beacon. The method of claim 9,
The method of operation of the reference node comprises:
Transmitting a control signal including information indicating a frequency band in which the beacon is transmitted through a predetermined frequency band,
Wherein the control signal is transmitted after the beacon in the superframe #n, and the predetermined frequency band is different from a frequency band in which the beacon is transmitted. As a device in a communication system,
A processor; And
Wherein at least one instruction executed by the processor comprises a stored memory,
Wherein the at least one instruction comprises:
Receiving a control signal including information indicating a frequency band #k to which beacon # 1 is transmitted from a reference node through a frequency band #m of a super frame #n;
Estimates a frequency band #p in which beacon # 2 is to be transmitted in superframe # n + 1 based on the frequency band #k and a preset frequency hopping pattern;
From the reference node through the frequency band #p of the superframe # n + 1, the beacon # 2 including setting information of a DL / UL slot (downlink / uplink slot);
Check the location of the DL / UL slot set in the superframe # n + 1 based on the setting 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 equal to or greater than 0, and each of k, m, and p is a different positive integer. 16. The method of claim 15,
The setting information includes information indicating a start time point 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,
Wherein the DL / UL slot according to the setting information is set in each of the superframes from the superframe # n + 1 to the superframe #j indicated by the valid section, and j is an integer greater than n + 1 , device. 16. The method of claim 15,
Wherein the uplink transmission operation is performed in the DL / UL slot when a downlink data unit is not received in a predetermined interval from the start time of the DL / UL slot. 16. The method of claim 15,
If a downlink data unit is not received in a predetermined interval from the start time of the DL / UL slot and there is no uplink data unit to be transmitted to the reference node, And operates in a sleep mode until a beacon period in the superframe # n + 2 located. 16. The method of claim 15,
Wherein the at least one instruction comprises:
Further comprising receiving from the reference node a DL bitmap indicating whether to transmit a downlink data unit in the DL / UL slot,
Wherein the DL bitmap is received via a separate message after receipt of the beacon # 2 or the beacon # 2. The method of claim 19,
Wherein the uplink transmission operation is performed in the DL / UL slot when the DL bitmap indicates that the downlink data unit is not transmitted in the DL / UL slot.

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