WO2017043905A1 - Data communication method and device using same - Google Patents

Abstract

A data communication method for a neighbor awareness network (NAN) and a device using the same are provided. A second NAN device receives, from a first NAN device, a paging message during a paging window, the paging message indicating that there is buffered traffic. The paging message includes an NAN paging ID for identifying the second NAN device and a channel access distribution factor. The second NAN device performs a backoff on the basis of the channel access distribution factor during a transmission window so as to determine whether a channel is idle.

Description

Data communication method and device using the same

The present invention relates to wireless communication, and more particularly, to a method for data communication in a neighbor awareness network (NAN) and a device using the same.

In general, a wireless communication system communicates between devices through a management medium such as a base station or an access point (AP). The management medium is responsible for scheduling for data communication.

In order to secure communication flexibility, various protocols for direct communication between devices without a management medium have been proposed. NAN (Neighbor Awareness Network) is a standard established by the Wi-Fi Alliance (WFA) based on the Wi-Fi standard. The NAN specification provides for synchronization, discovery and data communication procedures between devices in the 2.5 GHz or 5 GHz frequency band.

In device-to-device communication, it is necessary to reduce the power consumption of the device. There is a need for a method for data communication between devices while reducing power consumption.

The present invention provides a method for data communication in a neighbor awareness network (NAN) and a device using the same.

In one aspect, a data communication method for a neighbor awareness network (NAN) is provided. The method receives a paging message indicating that there is a buffered traffic from the first NAN device by the second NAN device during the paging window, wherein the paging message is a NAN paging ID and channel access distribution factor identifying the second NAN device. Wherein, during the transmission window, the second NAN device performs a backoff based on the channel access distribution factor to determine whether a channel is idle, and if the channel is idle, during the transmission window, the second NAN device Sending a trigger message informing of receipt of the paging message to the first NAN device.

In another aspect, a device for a neighbor awareness network (NAN) includes a transceiver for transmitting and receiving wireless signals and a processor coupled to the transceiver. The processor receives a paging message indicating that there is traffic buffered from the first NAN device by the second NAN device during the paging window, wherein the paging message is a NAN paging ID and a channel access distribution factor identifying the second NAN device. Wherein, during the transmission window, the second NAN device performs a backoff based on the channel access distribution factor to determine whether a channel is idle, and if the channel is idle, during the transmission window, the second NAN device Transmits a trigger message for notifying reception of the paging message to the first NAN device.

NAN (Neighbor Awareness Network) can reduce the power consumption of the device due to collision in channel access.

1 shows an example of a NAN topology.

2 shows a NAN data communication structure.

3 shows the operation in the discovery window.

4 shows a paging segment for data communication according to an embodiment of the present invention.

5 illustrates a data communication method according to an embodiment of the present invention.

6 is a block diagram illustrating a device in which an embodiment of the present invention is implemented.

NAN (Neighbor Awareness Network) is a standard established by the Wi-Fi Alliance (WFA) based on the Wi-Fi standard. NAN devices are devices that support the NAN standard. The NAN device may support various communication protocols and may be part of a station (STA) or part of an access point (AP). The STA may be fixed or mobile, and may include a user equipment (UE), a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a personal digital assistant (PDA), and a wireless modem ( It may be called other terms such as a wireless modem and a handheld device.

NAN devices can operate in the 2.5 GHz or 5 GHz frequency band and can exchange information based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11a / b / g / n / ac protocol.

The NAN device may search for a service of an adjacent device by using the NAN protocol, execute an application, and use the searched service by connecting to a wireless local area network (WLAN) or other network.

1 shows an example of a NAN topology.

The NAN cluster may be a set of NAN devices that share a set of NAN parameters and are synchronized to the same discovery window schedule. NAN devices participating in the same NAN cluster are synchronized to a common clock. The NAN parameter may include at least one of a duration of a discovery window, a discovery window interval, and a NAN channel. The discovery window interval refers to the time interval between successive discovery windows.

The NAN network may include at least one NAN cluster. The NAN device may join one or more NAN clusters.

NAN devices in a NAN cluster may operate in a master role or a non-master role. The NAN device operating in the master role may transmit a synchronization beacon frame and a discovery beacon frame. NAN devices operating in the sync state and non-master roles cannot transmit discovery beacon frames. NAN devices operating in a non-sync state and non-master role cannot transmit sync beacon frames and discovery beacon frames. Every NAN device can transmit a service discovery frame.

The synchronous beacon frame is used for synchronization of NAN devices in a NAN cluster. The discovery beacon frame is used to advertise the cluster to discover NAN devices that are not joined to the NAN cluster. The service discovery frame is used for exchanging information about a service between NAN devices.

2 shows a NAN data communication structure.

NAN Data Cluster (NDC) is a set of NAN Data Links (NDLs) having the same NAN data cluster basic schedule. NDL (NAN Data Link) means a negotiated resource block (RNB) between NAN devices. NAN Data Path (NDP) refers to a data connection established for service between NAN devices.

NDP is set to request service between NAN devices. NAN devices establish an NDL to share a resource (called RB) for data communication.

The NDC includes a plurality of NAN devices sharing a common NDC schedule in the same NAN cluster. Each member device in the NDC has at least one NDL with another member device. Each NDL has its own NDL schedule.

3 shows the operation in the discovery window.

The discovery window (DW) may be referred to as a time and channel at which NAN devices converge.

During the discovery window, one or more NAN devices may transmit a synchronous beacon frame, causing all NAN devices in the NAN cluster to synchronize. One NAN device may transmit one sync beacon frame during one discovery window.

Between the discovery windows, one or more NAN devices may transmit discovery beacon frames, allowing the NAN devices to discover the NAN cluster.

During the discovery window, the NAN device may transmit a service discovery frame on a contention basis. The NAN device may start a backoff timer set to an arbitrary value, and transmit a service discovery frame when the value of the backoff timer becomes zero.

4 shows a paging segment for data communication according to an embodiment of the present invention.

A paging portion is defined for data transmission between NAN devices. The paging segment includes a paging window (PW) and a subsequent transmission window (TW).

The paging window is a period in which the first NAN device transmits a paging message indicating that there is buffered traffic to the second NAN device. The device that will receive the buffered traffic is called a paged device.

The transmission window is a period in which the second NAN device transmits a trigger message and maintains a wakeup state for receiving buffered traffic. A NAN device that does not receive a paging message during the paging window, or whose identity is not identified in the paging message, may enter a sleep state during the transmission window. The first NAN device that receives the trigger message during the transmission window may transmit the buffered traffic to the second NAN device.

5 illustrates a data communication method according to an embodiment of the present invention.

The first NAN device and the second NAN device belong to the same NAN cluster. The first NAN device initiates the NDL setup process and is called an initiator to send a paging message, and the second NAN device is called a responder.

In step S510, the first NAN device transmits an NDL setup request for NDL setup to the second NAN device. The NDL setup request includes information about a paging segment and information about an NDL paging identifier identifying a paged device within the paging segment. The NDL paging ID may have a bit number of one octet, but is not limited thereto.

In step S520, the second NAN device transmits an NDL setup response indicating that the NDL setup is accepted.

In step S530, during the paging window, the first NAN device transmits a paging message indicating that there is buffered traffic to the second NAN device. The paging message may include information indicating the NDL paging ID of the second NAN device.

Table 1 below shows an example of paging information in a paging message. Not all elements are required, and the names and number of bits are examples only.

field Number of bits Contents ID offset 8 Start offset ID bitmap - Bitmaps for Paged Devices Access distribution factor 8 Factor for distributing channel access of the NAN device receiving this messaging message. QoS Category 8 Indicates the QoS access category in the transmission window. For example, AC_BE (access category for best effort), AC_BK (access category for background), AC_VI (access category for video traffic), AC_VO (access category for voice traffic)

The ID offset is the NDL paging ID corresponding to the first of the ID bitmap. The paged device is a device whose NDL paging ID corresponds to ID offset + n. Here, n is the n + 1 th bit in the ID bitmap is set to '1'.

Table 2 below shows another example of paging information in a paging message.

field Number of bits Contents NDL Paging ID List - NDL paging ID list of devices being paged Access distribution factor 8 Factor for distributing channel access of the NAN device receiving this messaging message. QoS Category 8 Indicates the QoS access category in the transmission window. For example, AC_BE (access category for best effort), AC_BK (access category for background), AC_VI (access category for video traffic), AC_VO (access category for voice traffic)

In step S540, during the transmission window, the second NAN device checks whether the channel is idle. If the channel is busy, wait for a backoff time and then check again whether the channel is idle. A method of setting the backoff time will be described later.

In step S550, when the channel is idle, the second NAN device transmits a trigger message to the first NAN device. The trigger message may be a quality of service (QoS) null frame.

In operation S560, the first NAN device receiving the trigger message transmits the buffered traffic to the second NAN device.

During the paging window, the first NAN device may transmit a paging message to the plurality of devices. This means that there are a plurality of paged devices. If multiple paged devices attempt channel access simultaneously during the transmission window, it may be difficult to send a trigger message due to a collision.

Hereinafter, a method of distributing channel access in a transmission window will be described.

In the existing WLAN, the backoff time T _bbackoff is _defined as T _backoff = Random () × _aSlotTime . Random () is a value determined randomly at interval [0, CW]. CWmin <= CW <= aCWmax. aSlotTime is a value determined according to the characteristics of the physical layer (PHY) and may be a basic time unit for performing a clear channel assessment (CCA).

In order to distribute the channel access of the trigger message, it is proposed to adjust the minimum value aCWmin or the maximum value aCWmax of the contention window during the transmission window. For clarity, the following examples describe adjusting aCWmin, but can also be applied to aCWmax.

The backoff time in the transmission window may be determined based on the access distribution factor. More specifically, the minimum value of the contention window in the transmission window may be determined based on the access distribution factor.

Define the following parameters:

tCWmin: minimum value of the contention window used for the backoff time for trigger messages and / or buffered traffic in the transmission window.

N: Access distribution factor given in the paging message received during the paging window.

aCWmin: Minimum value of the basic competition window or minimum value of the competition window defined in the corresponding access category.

In the first embodiment, tCWmin = N * aCWmin can be determined.

In a second embodiment, tCWmin = N '* aCWmin can be determined. Here, N 'is a value randomly determined in [1, N]. That is, 1 <= N '<= N. N 'may be randomly determined by the paged device.

Channel access can be distributed by varying the backoff time of the device depending on the access distribution factor during the transmission window. The paged device can reduce collisions for sending trigger messages. Channel access for the transmission of buffered traffic may be distributed.

The first NAN device may dynamically adjust the access distribution factor according to the channel state. The higher the load on the channel, the larger the value of the access distribution factor can be conveyed.

Arbitration interframe space numbers (AIFSNs) during the transmission window may also be determined based on the access distribution factor. AIFSN is the time the NAN device waits before sending the next message. The adjusted AIFSN 'may be determined as AIFSN' = N * AIFSN or AIFSN '= N' * AIFSN.

6 is a block diagram illustrating a device in which an embodiment of the present invention is implemented.

The device 100 may perform an operation of the NAN device according to the proposed embodiment. The device 100 includes a processor 110, a memory 120, and a transceiver 130. The memory 120 is connected to the processor 110 to store various instructions executed by the processor 110. The transceiver 130 is connected to the processor 110 to transmit and / or receive a radio signal. The processor 110 implements the proposed functions, processes and / or methods. In the above-described embodiment, the processor 110 implements the NAN protocol, and the discovery process and the data communication process may be implemented by the processor 110. When the above-described embodiments are implemented as software instructions, the instructions may be stored in the memory 120 and executed by the processor 110 to perform the above-described operations.

The processor may include application-specific integrated circuits (ASICs), other chipsets, logic circuits, and / or data processing devices. The memory may include read-only memory (ROM), random access memory (RAM), flash memory, memory card, storage medium and / or other storage device. The RF unit may include a baseband circuit for processing a radio signal. When the embodiment is implemented in software, the above-described technique may be implemented as a module (process, function, etc.) for performing the above-described function. The module may be stored in memory and executed by a processor. The memory may be internal or external to the processor and may be coupled to the processor by various well known means.

In the exemplary system described above, the methods are described based on a flowchart as a series of steps or blocks, but the invention is not limited to the order of steps, and certain steps may occur in a different order or concurrently with other steps than those described above. Can be. In addition, those skilled in the art will appreciate that the steps shown in the flowcharts are not exclusive and that other steps may be included or one or more steps in the flowcharts may be deleted without affecting the scope of the present invention.

Claims (11)

In the data communication method for NAN (Neighbor Awareness Network), During the paging window, the second NAN device receives a paging message indicating that there is buffered traffic from the first NAN device, the paging message including a NAN paging ID and a channel access distribution factor identifying the second NAN device; ; During the transmission window, the second NAN device performs a backoff based on the channel access distribution factor to determine whether the channel is idle; And if the channel is idle, sending a trigger message to the first NAN device to notify the receipt of the paging message during the transmission window. The method of claim 1, And a backoff time for the backoff is determined based on the channel access distribution factor. The method of claim 2, And a contention window used to determine a backoff time for the backoff is determined based on the channel access distribution factor. The method of claim 3, wherein The minimum value of the contention window is determined based on the channel access distribution factor. The method of claim 1, And wherein the second NAN device receives the buffered traffic from the first NAN device during the transmission window. The method of claim 1, And the second NAN device receives a NAN Data Link (NDL) setup request with information about the paging window from the first NAN device. The method of claim 1, And the paging window and the transmission window are contiguous. In the device for the NAN (Neighbor Awareness Network), A transceiver for transmitting and receiving wireless signals; and A processor coupled to the transceiver, wherein the processor includes: During the paging window, the second NAN device receives a paging message indicating that there is buffered traffic from the first NAN device, the paging message including a NAN paging ID and a channel access distribution factor identifying the second NAN device; ; During the transmission window, the second NAN device performs a backoff based on the channel access distribution factor to determine whether the channel is idle; And when the channel is idle, transmitting a trigger message informing the reception of the paging message from the second NAN device to the first NAN device during the transmission window. The method of claim 8, And the backoff time for the backoff is determined based on the channel access distribution factor. The method of claim 9, Wherein the contention window used to determine a backoff time for the backoff is determined based on the channel access distribution factor. The method of claim 10, The minimum value of the contention window is determined based on the channel access distribution factor.

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