KR101258058B1 - Communication device using phy layer header including destination mac address and method using the device - Google Patents

Abstract

PURPOSE: A communications device using physical layer headers containing the MAC(Media Access Control) address of a destination, and a communications method using the same are provided to prevent resource consumption for decoding the entire MAC data frame included in a third sub-frame which is included in a physical layer protocol data unit, in an overhearing process. CONSTITUTION: A physical layer protocol data unit(100) includes a first sub-frame(110), a second sub-frame(120), and a third sub-frame(130). The first sub-frame includes synchronization information(111) for the synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit. The second sub-frame includes a physical layer header(121) containing a first identifier(122) identifying the receiver. The third sub-frame includes data(133) and a MAC protocol data unit(131) containing a second identifier(132) identifying the receiver. The first sub-frame and the second sub-frame are decoded in the physical layer, and the third sub-frame is decoded in the MAC layer. [Reference numerals] (100) Physical layer protocol data unit; (110) First sub-frame; (111) Synchronization information; (120) Second sub-frame; (121) PHY layer header; (122) First identifier; (130) Third sub-frame; (131) MAC protocol data unit; (132) Second identifier; (133) Data;

Description

TECHNICAL DEVICE USING PHY LAYER HEADER INCLUDING DESTINATION MAC ADDRESS AND METHOD USING THE DEVICE}

The following embodiments are related to a communication device using frame data and a communication method using the same.

The IEEE 802.11 standard performs communication based on a CSMA / CA scheme, which is a content-based access mechanism, in order to access a communication medium when using a distributed coordination function (DCF) mode. In the DCF mode, a physical carrier and a virtual carrier are detected. When the communication device detects a channel, the communication device decodes an uplink frame and a downlink frame to confirm whether the sensed medium has been transmitted for itself. This phenomenon is called overhearing, and a communication device must consume enormous energy in order to perform overhearing.

The present invention includes a first identifier for identifying a receiver for receiving the physical layer protocol data unit in a second subframe included in a physical layer protocol data unit used in a communication device, thereby performing the physical operation in an overhearing process. Provided is a technique for preventing resource consumption that requires decoding of the entire MAC data frame included in the third subframe included in the layer protocol data unit.

A communication apparatus according to an embodiment of the present invention includes a physical layer protocol data unit including a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer. Generation unit for generating a; And a transmitter for transmitting the physical layer protocol data unit, wherein the first subframe includes synchronization information for synchronization between a receiver for receiving the physical layer protocol data unit and a transmitter for transmitting the physical layer protocol data unit. Wherein the second subframe includes a PHY layer header that includes a first identifier identifying the receiver, and wherein the third subframe includes data and a second identifier identifying the receiver It includes.

A communication apparatus according to an embodiment of the present invention includes a physical layer protocol data unit including a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer. Receiving unit for receiving; A first decoder to decode the second subframe in the PHY layer; A determination unit to determine whether to decode the third subframe in the MAC layer using the decoded second subframe; In response to determining that the third subframe is decoded in the MAC layer, a second decoding unit that decodes the third subframe in the MAC layer, wherein the first subframe receives the physical layer protocol data unit. A synchronization information for synchronization between a receiver and a transmitter transmitting the physical layer protocol data unit, wherein the second subframe includes a PHY layer header including a first identifier identifying the receiver; The subframe includes a MAC protocol data unit containing data and a second identifier identifying the receiver.

Each of the first identifier and the second identifier may identify the receiver according to the MAC address of the receiver.

The first identifier may identify the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.

The synchronization information includes any one of PLCP sublayer preambles of all wireless LAN protocols including IEEE 802.11a standard protocol, IEEE 802.11g standard protocol, IEEE 802.11n standard protocol, and IEEE 802.11ac standard protocol, The PHY layer header may further include any one of PLCP sublayer headers of all the wireless LAN protocols.

The physical layer protocol data unit used in the communication apparatus according to an embodiment of the present invention includes synchronization information for synchronization between a receiver for receiving the physical layer protocol data unit and a transmitter for transmitting the physical layer protocol data unit. A first subframe; A second subframe including a PHY layer header including a first identifier identifying the receiver; And a third subframe comprising a MAC protocol data unit comprising data and a second identifier identifying the receiver.

Each of the first identifier and the second identifier may use a physical layer protocol data unit that identifies the receiver according to the MAC address of the receiver.

The first identifier may use a physical layer protocol data unit identifying the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.

The synchronization information includes any one of PLCP sublayer preambles of all wireless LAN protocols including IEEE 802.11a standard protocol, IEEE 802.11g standard protocol, IEEE 802.11n standard protocol, and IEEE 802.11ac standard protocol, The PHY layer header may use a physical layer protocol data unit further comprising any one of the PLCP sublayer headers of all the wireless LAN protocols.

A communication method according to an embodiment of the present invention includes a physical layer protocol data unit including a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer. Generating a; And transmitting the physical layer protocol data unit, wherein the first subframe includes synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit. Wherein the second subframe includes a PHY layer header that includes a first identifier identifying the receiver, and wherein the third subframe includes data and a second identifier identifying the receiver It includes.

A communication method according to an embodiment of the present invention includes a physical layer protocol data unit including a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer. Receiving; Decoding the second subframe in the PHY layer; Determining whether to decode the third subframe in the MAC layer using the decoded second subframe; Decoding the third subframe at the MAC layer according to a determination to decode the third subframe at the MAC layer, wherein the first subframe is configured to receive the physical layer protocol data unit; Synchronization information for synchronization between transmitters transmitting the physical layer protocol data units, wherein the second subframe includes a PHY layer header including a first identifier identifying the receiver, and the third subframe Includes a MAC protocol data unit comprising data and a second identifier identifying the receiver.

Each of the first identifier and the second identifier may identify the receiver according to the MAC address of the receiver.

The first identifier may identify the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.

The synchronization information includes any one of PLCP sublayer preambles of all wireless LAN protocols including IEEE 802.11a standard protocol, IEEE 802.11g standard protocol, IEEE 802.11n standard protocol, and IEEE 802.11ac standard protocol, The PHY layer header may further include any one of PLCP sublayer headers of all the wireless LAN protocols.

The present invention includes a first identifier for identifying a receiver for receiving the physical layer protocol data unit in a second subframe included in a physical layer protocol data unit used in a communication device, thereby performing the physical operation in an overhearing process. It is possible to provide a technique for preventing resource consumption that requires decoding of the entire MAC data frame included in the third subframe included in the layer protocol data unit.

1 is a block diagram illustrating a physical layer protocol data unit used in a communication device according to an embodiment of the present invention.
2 is a diagram illustrating a physical layer protocol data unit including information about a wireless LAN protocol used in a communication device according to an embodiment of the present invention.
3 is a block diagram illustrating a communication device according to an embodiment of the present invention.
4 is a flowchart illustrating a communication method according to an embodiment of the present invention.
5 is a diagram illustrating a physical layer protocol data unit and a MAC data frame according to the IEEE 802.11a standard.
FIG. 6 is a diagram illustrating a physical layer protocol data unit including a PLCP header including lower 18 bits of a MAC address of a destination according to an embodiment of the present invention.
7 is a diagram illustrating a transmission time of a PLCP header portion including lower 18 bits of a MAC address of a destination according to an embodiment of the present invention.
8 is a view for explaining the energy efficiency of the communication method according to an embodiment of the present invention.

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

1 is a block diagram illustrating a physical layer protocol data unit used in a communication device according to an embodiment of the present invention.

Referring to FIG. 1, a physical layer protocol data unit 100 used in a communication device according to an embodiment of the present invention is provided between a receiver for receiving the physical layer protocol data unit and a transmitter for transmitting the physical layer protocol data unit. A first subframe 110 including synchronization information 111 for synchronization of a; A second subframe (120) comprising a PHY layer header (121) comprising a first identifier (122) identifying the receiver; And a third subframe 130 including a MAC protocol data unit 131 including data 133 and a second identifier 132 identifying the receiver. In this case, the first subframe 110 and the second subframe 120 may be decoded in the PHY layer, and the third subframe 130 may be decoded in the MAC layer.

The physical layer protocol data unit 100 used in the communication device according to an embodiment of the present invention includes the first layer 122 identifying the receiver in the second subframe 120, thereby providing the physical layer protocol. It is possible to determine whether the physical layer protocol data unit 100 has been transmitted to the receiver without decoding the entire data unit 100.

More specifically, the communication device using the conventional physical layer protocol data unit may transmit the conventional physical layer protocol data unit to the corresponding receiver by using the second identifier 132 included in the third subframe 130. Determine whether or not. In this case, the MAC protocol data unit is used to determine whether the physical layer protocol data unit 100 has been transmitted to the receiver using the second identifier 132 included in the third subframe 130. 131 should be decoded in the MAC layer. In this case, the MAC protocol data unit 131 includes a second identifier 132 and data 133 of the physical layer protocol data unit 100, and only the second identifier 132 can be decoded separately. Since the data 133 must be decoded together. On the other hand, the physical layer protocol data unit 100 used in the communication apparatus according to an embodiment of the present invention may be separately formed in the second subframe 120 in addition to the second identifier included in the third subframe 130. One identifier 122. The communication apparatus according to an embodiment of the present invention decodes the second subframe 120 in the PHY layer by using the first identifier 122 included in the second subframe 120. It may be determined whether the layer protocol data unit 100 has been transmitted to the receiver.

That is, the communication device according to the embodiment of the present invention uses the first identifier 122 included in the second subframe 120 to allow the physical layer protocol data unit 100 to communicate with the communication device, that is, the receiver. Determining whether or not the data transmission method is transmitted with respect to the network, it is possible to reduce energy consumption incurred in decoding the entire physical layer protocol data unit when the physical layer protocol data unit 100 is not transmitted to the receiver. More specific matters related to the effects of the communication device according to the embodiment of the present invention will be described later.

2 is a diagram illustrating a physical layer protocol data unit including information about a wireless LAN protocol used in a communication device according to an embodiment of the present invention.

Prior to describing a physical layer protocol data unit including information on a wireless LAN protocol used in a communication apparatus according to an embodiment of the present invention with reference to FIG. 2, the PHY sublayer is briefly described. Explain.

The PLCP sublayer is a sublayer in the IEEE 802.11 PHY layer, which is a wireless LAN standard, and refers to a layer that allows the IEEE 802.11 MAC layer to operate regardless of physical characteristics. The PLCP sublayer serves to connect the IEEE 802.11 MAC layer and the physical layer protocol data unit, and may add its own header for this purpose. In addition, the PLCP frame is defined differently according to various wireless LAN PHY layer standards, so that a frame format suitable for each of the wireless LAN PHY layer standards can be applied. More specifically, the PLCP sublayer may receive a command of the MAC sublayer in the upper data link layer and mainly transmit a frame received from a wireless medium to the MAC sublayer.

2, a PHY layer header 220 included in a physical layer protocol data unit used in a communication device according to an embodiment of the present invention is a first identifier for identifying a receiver for receiving the physical layer protocol data unit. 222, and the MAC protocol data unit 230 included in the physical layer protocol data unit used in the communication device according to the embodiment of the present invention may include a second identifier 231 for identifying the receiver; May include data 232.

In addition, the synchronization information 210 included in the physical layer protocol data unit used in the communication apparatus according to an embodiment of the present invention is one of PLCP sublayer preambles of all wireless LAN protocols including the IEEE 802.11a standard protocol. It may include any one (211). In this case, the PLCP sublayer preamble 211 may be a signal for synchronization and channel estimation of the PHY layer in a wireless LAN protocol corresponding to any one PLCP sublayer preamble 211. More specifically, the PLCP sublayer preamble 211 includes ten short pilot signals for signal detection, automatic gain control (AGC), diversity selection, fine time synchronization, and the like; And two long pilot signals for channel estimation, fractional frequency error estimation, and the like.

In addition, the PHY layer header 220 included in the physical layer protocol data unit used in the communication apparatus according to an embodiment of the present invention is one of PLCP sublayer headers of all wireless LAN protocols including the IEEE 802.11a standard protocol. It may further include any one (221). In this case, the PLCP sublayer header 221 may include a transmission rate of a data frame, a length of data included in the data frame, a parit bit, and the like.

In this case, each of the first identifier 222 and the second identifier 231 may identify the receiver according to the MAC address of the receiver.

The MAC address may refer to a physical address implemented on 48-bit hardware for identification of a device on the MAC layer. More specifically, Ethernet's MAC layer frame may contain a 48-bit destination address, of which the top 24 bits (which are likely to overlap) are organized by OUI (Organizationally identifying the LAN card manufacturer). Unique Identifier), and the lower 24 bits (depending on the station) may include an address individually assigned by the manufacturer. As a result, MAC addresses may be unique worldwide.

Each of the first identifier 222 and the second identifier 231 included in a physical layer protocol data unit used in a communication device according to an embodiment of the present invention is assigned to a MAC address associated with the destination address. Information may be included. The communication device according to an embodiment of the present invention compares the MAC address associated with the destination address included in the first identifier 222 with its own MAC address, thereby receiving a data frame received by the communication device. It may be determined whether or not the communication device has been transmitted to the receiver.

In addition, the first identifier 222 may identify the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.

The physical layer protocol data unit used in the communication device according to an embodiment of the present invention may further include the first identifier 222 as compared to the conventional physical layer protocol data unit. As described above, by using the additionally included first identifier 222 received by the communication device without decoding the entire MAC data frame included in the third sub-frame included in the physical layer protocol data unit It may be determined whether a physical layer protocol data unit has been transmitted to the communication device, that is, the receiver. However, the transmission of the physical layer protocol data unit used in the communication apparatus according to an embodiment of the present invention is more than that of the conventional physical layer protocol data unit, and the length of the additional first identifier 222 is increased. It can consume more energy for transmitting data.

The first identifier 222 included in the physical layer protocol data unit used in the communication device according to an embodiment of the present invention is a predetermined number of MAC addresses associated with a destination included in the aforementioned MAC layer frame. The lower N bits of may be included. In this case, even if it is determined that the physical layer protocol data unit has been transmitted to the communication device (receiver) that has received the physical layer protocol data unit using the first identifier 222, that is, the predetermined number of times. Even if the lower N bits are the same as the lower N bits of the MAC address of the receiver, the upper bits not included in the first identifier 222 may not match the upper bits of the MAC address of the receiver.

Accordingly, the communication device according to an embodiment of the present invention may adjust the length of the added first identifier. In this way, the communication apparatus according to an embodiment of the present invention includes energy waste generated from adding the first identifier to a second subframe of a physical layer protocol data unit; And the accuracy of identifying the receiver depending on the number of lower N bits of the MAC address associated with the destination of the physical layer protocol data unit included in the first identifier. The first identifier 222 included in a physical layer protocol data unit used in a communication device according to an embodiment of the present invention is a lower N (eg, N = 18) of a MAC address associated with the destination address. May include bits.

Meanwhile, the second identifier 231 included in the physical layer protocol data unit used in the communication device according to an embodiment of the present invention may include a MAC address associated with the destination address.

3 is a block diagram illustrating a communication device according to an embodiment of the present invention.

Referring to FIG. 3, a communication device 310 according to an embodiment of the present invention may include a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subcode decoded in a MAC layer. A generation unit 311 for generating a physical layer protocol data unit including a frame; And a transmitter 312 for transmitting the physical layer protocol data unit.

In addition, the communication device 320 according to an embodiment of the present invention includes a first subframe decoded in the PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in the MAC layer. A receiving unit 321 for receiving a physical layer protocol data unit; A first decoding unit (322) for decoding the second subframe in the PHY layer; A determination unit (323) for determining whether to decode the third subframe in the MAC layer using the decoded second subframe; According to the determination of decoding the third subframe in the MAC layer, the second decoding unit 324 may decode the third subframe in the MAC layer.

In this case, the first subframe includes synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit, and the second subframe includes the receiver. And a PHY layer header including a first identifier to identify, wherein the third subframe includes a MAC protocol data unit including data and a second identifier to identify the receiver.

In addition, the synchronization information included in the physical layer protocol data unit used in the communication device according to an embodiment of the present invention is any one of the PLCP sublayer preambles of all wireless LAN protocols including the IEEE 802.11a standard protocol. It may include.

In addition, the PHY layer header included in the physical layer protocol data unit used in the communication device according to an embodiment of the present invention is any one of the PLCP sublayer headers of all wireless LAN protocols including the IEEE 802.11a standard protocol. It may further include.

In addition, each of the first identifier and the second identifier may identify the receiver according to the MAC address of the receiver, and the first identifier may be determined according to a predetermined number of lower bits of the MAC address of the receiver. The receiver can be identified. More specifically, each of the first identifier 222 and the second identifier 231 may include information on a MAC address associated with a destination address of the physical layer protocol data unit.

In this case, the determination unit 323 included in the communication apparatus according to an embodiment of the present invention may decode the third subframe in the MAC layer using a first identifier included in the decoded second subframe. It can be determined. The determination unit 323 compares the MAC address associated with the lower N bits of the destination address included in the first identifier with the lower N bits of the MAC address of the communication device 320 to thereby perform the third operation. It may be determined whether to decode a subframe in the MAC layer.

More specifically, the determination unit 323 included in the communication device according to an embodiment of the present invention may include the MAC address and the communication device related to the lower N bits of the destination address included in the first identifier. If the predetermined lower N bits of the MAC address of 320 match, it is determined that the third subframe is decoded in the MAC layer, and the predetermined lower N bits of the destination address included in the first identifier are determined. If the associated MAC address and the lower N bits of the MAC address of the communication device 320 do not match, it may be determined that the third subframe is not decoded in the MAC layer.

The communication device according to an embodiment of the present invention increases energy efficiency of the communication device by not decoding the third subframe in the MAC layer according to the determination that the third subframe is not decoded in the MAC layer. Can be.

In addition, the first identifier included in the physical layer protocol data unit used in the communication apparatus according to an embodiment of the present invention may identify the receiver according to predetermined low bits of N bits of the MAC address of the receiver. The first identifier may include a predetermined number of lower bits among MAC addresses associated with a destination address of the physical layer protocol data unit. In this case, the communication device according to an embodiment of the present invention is an energy waste generated by adding the first identifier to the second subframe of the physical layer protocol data unit by adjusting the length of the first identifier; And the accuracy of identifying the receiver depending on the number of lower bits of the MAC address associated with the destination of the physical layer protocol data unit included in the first identifier. In this regard, since the matters described with reference to FIG. 2 may be applied as it is, a detailed description thereof will be omitted.

4 is a flowchart illustrating a communication method according to an embodiment of the present invention.

4, a communication method 410 according to an embodiment of the present invention includes a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subcode decoded in a MAC layer. Generating (411) a physical layer protocol data unit comprising a frame; And transmitting 412 the physical layer protocol data unit.

In addition, the communication method 420 according to an embodiment of the present invention includes a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer. Receiving (421) a physical layer protocol data unit; Decoding (422) the second subframe at the PHY layer; Determining (423) whether to decode the third subframe in the MAC layer using the decoded second subframe; In operation 424, the third subframe may be decoded in the MAC layer according to the determination of decoding the third subframe in the MAC layer.

In this case, the first subframe includes synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit, and the second subframe includes the receiver. And a PHY layer header including a first identifier to identify, wherein the third subframe includes a MAC protocol data unit including data and a second identifier to identify the receiver.

In addition, the synchronization information included in the physical layer protocol data unit used in the communication device according to an embodiment of the present invention is any one of the PLCP sublayer preambles of all wireless LAN protocols including the IEEE 802.11a standard protocol. May contain

In addition, the PHY layer header included in the physical layer protocol data unit used in the communication device according to an embodiment of the present invention is any one of the PLCP sublayer headers of all wireless LAN protocols including the IEEE 802.11a standard protocol. It may further include.

In addition, each of the first identifier and the second identifier may identify the receiver according to the MAC address of the receiver, and the first identifier may be determined according to the lower bits of a predetermined N bit among the MAC addresses of the receiver. The receiver can be identified.

Since the details described with reference to FIGS. 1 to 3 may be applied to each of the steps illustrated in FIG. 4, a detailed description thereof will be omitted.

The methods described above may be embodied in the form of program instructions that may be executed by various computer means and may be recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. The program instructions recorded on the 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 magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically 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 produced 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 as one or more software modules to perform the operations of the present invention, and vice versa.

Hereinafter, an embodiment of the present invention in which the physical layer protocol data unit and the MAC data frame according to the IEEE 802.11a standard are modified will be described in detail with reference to FIGS. 5 to 8. Hereinafter, the present invention will be described based on an embodiment of the present invention according to the IEEE 802.11a standard protocol. However, the present invention can be applied to other wireless LAN protocols such as the IEEE 802.11g standard protocol, the IEEE 802.11n standard protocol, and the IEEE 802.11ac standard protocol. Do.

1. Overview of System Models and IEEE 802.11 Standards

A communication device according to an embodiment of the present invention may operate in an environment including a plurality of communication devices and one repeater in a communication system supporting the IEEE 802.11a PHY layer.

A. Overview of the IEEE 802.11a PHY Layer Standard

The IEEE 802.11a PHY layer is based on OFDM. The basic principle of OFDM is to divide a single high speed binary signal into a plurality of low speed subcarriers. The IEEE 802.11a PHY layer supports eight PHY modes, each of which has a different modulation scheme, coding scheme, and frequency band. See Table 1 for this.

Modulation Code Rate R Data Rate BpS One BPSK 1/2 6 Mbps 3 2 BPSK 3/4 9 Mbps 4.5 3 QPSK 1/2 12 Mbps 6 4 QPSK 3/4 18 Mbps 9 5 16-QAM 1/2 24 Mbps 12 6 16-QAM 3/4 36 Mbps 18 7 64-QAM 2/3 48 Mbps 24 8 64-QAM 3/4 54 Mbps 27

B. Overview of the IEEE 802.11a MAC Layer Standard

The IEEE 802.11a MAC layer protocol consists of a point coordination function (PCF) and a distributed coordination function (DCF). PCF is a polling based method and must maintain a polling list.

DCF, on the other hand, is based on CSMA / CA and uses a contention based approach mechanism. The communication device may transmit a pending MAC protocol data unit (MPDU) when it is determined that the channel is empty for a period longer than or equal to a Data InterFrame Space (DIFS) or Extended InterFrame Space (EIFS). The backoff counter may be initialized after the time as much as the DIFS has elapsed, and the frame may be transmitted when the backoff counter reaches zero.

C. Frame Format of IEEE 802.11a

5 is a diagram illustrating a physical layer protocol data unit and a MAC data frame according to the IEEE 802.11a standard.

Referring to FIG. 5, when a communication device according to an embodiment of the present invention processes an MPDU in a PLCP sublayer, the MPDU may be referred to as a physical service data unit (PSDU) 530. The MAC protocol data unit includes a MAC header 531, data 532, and frame check sequence. The MAC header 531 is 22 bytes and the frame check sequence is 4 bytes.

In addition, the MAC header 531 may include MAC addresses 533, 534, 535, and 536, which may represent physical addresses implemented on 48-bit hardware for identification of devices on the MAC layer. The upper 24 bits may include an Organizationally Unique Identifier (OUI) that identifies the LAN card manufacturer, and the lower 24 bits may include an address that the manufacturing company individually attaches.

The PLCP header 520 includes a 4-bit RATE field, a 12-bit LENGTH field, a 1-bit Parity field, a 6-bit Tail field, and a 16-bit SERVICE field, and includes a PLCL preamble field 510 in the PLCP header. The added frame format may be referred to as a PLCP protocol data unit.

The PLCP preamble field 510 consists of repetitions of 10 short training sequences and repetitions of two long training sequences. A part of the PLCP header except for the SERVICE field may configure an OFDM symbol.

2. Energy Consumption Models of Conventional Communication Devices

A. Saturated Case

With regard to the energy efficiency of the communication device according to an embodiment of the present invention, it is possible to analyze not the energy consumption for one link but the energy consumption consumed by the entire network.

In this case, the time taken to transmit a data frame of the IEEE 802.11a standard having a payload size of L bytes can be expressed as follows.

(Equation 1)

Here, tPLCP_Preamble, tPLCP_SIG, and tSymbol may be calculated using Table 2, respectively.

Characteristics Value Comments tSlotTime 9 ㎲ Slot time tSIFSTime 16 ㎲ SIFS time tDIFSTime 34 ㎲ DIFS = SIFS + 2 * Slot aCWmin 15 Min contention window aCWmax 1023 Max contention window tPLCPPreamble 16 ㎲ PLCP Preamble duration tPLCP_SIG 4 ㎲ PLCP SIGNAL field duration tSymbol 4 ㎲ OFDM symbol interval

As described above, the communication device according to an embodiment of the present invention may be a basic environment in which a plurality of communication devices and one repeater perform communication under the IEEE 802.11a MAC standard using the DCF mode. In the state where the plurality of communication devices are saturated, the throughput of the IEEE 802.11 network may be expressed as follows.

(Formula 2)

In this case, the saturation state of the plurality of communication devices indicates a state in which each of the plurality of communication devices always has a packet to transmit, and the packet has a payload of L bytes.

Pr _tr denotes the probability that there is at least one data transmission, Pr _s denotes the probability that the data transmission is successful, T _s denotes the time taken for the successful data transmission, and T _c denotes the collision The average time is shown and T _δ represents the idle time.

The total energy consumption per unit time on the hypothesized network can be expressed as follows.

(Equation 3)

는 충돌이 일어난 경우 소모되는 에너지를 나타내며, E_δ는 idle 상태에서 소모되는 에너지를 나타낸다. 보다 구체적으로는 E_s, E_c, 및 E_δ는 각각 다음과 같이 표현될 수 있다.
Where E _s represents the energy consumed for successful packet transmission,

Represents the energy consumed in the event of a collision, and E _δ represents the energy consumed in the idle state. More specifically, E _s , E _c , and E _δ may each be expressed as follows.

(Formula 3a)

(Formula 3b)

(Formula 3c)

Here, Pr _{c , k} and E _{c , k} may be expressed as follows, respectively.

(Formula 3d)

(Equation 3e)

In addition, P _tx , P _rx , and P _idle each represent power consumption during packet transmission, packet reception, and idle state. τ represents a probability that one communication device transmits in a randomly selected time slot.

B. Unsaturated Case

In a state where the plurality of communication devices are not saturated, each of the plurality of communication devices may wait for a packet to be delivered at an upper layer of the MAC layer. Thus, the probability that one communication device transmits a data frame in a randomly selected time slot may depend on λ. Where λ represents the communication device transmission probability.

(Equation 4)

When λ is 1, the equation for τ is the same as the equation for a plurality of communication devices saturated.

The throughput of the communication system when the plurality of communication devices are not saturated may be defined as the percentage of time that the channel was used to successfully transmit payload data.

(Equation 5)

Here, Pr _tr represents a probability that at least one data transmission occurs in one slot, and Pr _s represents a probability that the data transmission succeeds.

The energy consumed per unit time by the network in the MAC layer can be expressed as follows.

(Equation 6)

Here, E _s may be calculated by Equation (5), E _c , and E _δ by Equation 3b and Equation 3c.

3. Physical Layer Protocol Data Unit (or PHY PDU) Structure Used in Communication Device According to One Embodiment of the Present Invention

6 is a diagram illustrating a physical layer protocol data unit including lower 18 bits of a receiver in a PLCP header according to an embodiment of the present invention.

Prior to describing a physical layer protocol data unit including lower N bits (eg, N = 18) of a receiver according to an embodiment of the present invention in a PLCP header with reference to FIG. 6, in relation to overhearing, FIG. Briefly explain.

When the communication device listens to the channel, the communication device must decode the received physical layer protocol data unit to determine whether the received physical layer protocol data unit has been sent to it. This step is called overhearing, and in the overhearing process, the communication device must decode the entire received physical layer protocol data unit.

More specifically, in order to determine whether the communication device receives the received physical layer protocol data unit, it is necessary to decode the PSDU 630 included in the received physical layer protocol data unit in the MAC layer. In this case, the MAC protocol data unit 630 includes not only the MAC address associated with the destination of the physical layer protocol data unit, but also data of the physical layer protocol data unit, and the communication device includes the MAC. Since only the address cannot be decoded separately, the data must be decoded together. This can cause huge resource consumption.

Referring to FIG. 6, in one embodiment of the present invention, the communication device may include the MAC address 625 of the receiving communication device in the PLCP sublayer header 620. The physical layer protocol data unit according to an embodiment of the present invention may include the lower N bits (eg, N = 18) 625 of the 48 bits MAC address of the receiving communication device in the PLCP header space 620.

In this case, the communication device according to an embodiment of the present invention uses the MAC address 625 of the lower N bits (eg, N = 18) included in the PLCP header 620 to determine the physical layer protocol data unit. The transmitted receiver can be identified. That is, by including the MAC address 625 of the receiving communication device in the PLCP header 620, it is possible to prevent the resource consumption to decode the entire physical layer protocol data unit received during the overhearing process.

The communication device according to an embodiment of the present invention decodes only the PLCP preamble 610 and the PLCP header 620 in the PHY layer using the MAC address 625 of the received communication device included in the PLCP header. It may be determined whether the physical layer protocol data unit has been transmitted to it.

4. Energy Consumption Model of Communication Device According to One Embodiment of the Present Invention

The time required for the transmission of the physical layer protocol data unit using the m mode (see Table 1) among the plurality of PHY modes may be expressed as follows.

(Formula 7)

When using a physical layer protocol data unit used in a communication device according to an embodiment of the present invention, the total energy consumption per unit time may be expressed as follows.

(Equation 8)

Here, each of E _s , E _c , and E _δ may be expressed as follows.

(Formula 9)

Es formula according to according to an embodiment of the present invention has the formula and a difference according to conventional E _s. When a packet is successfully transmitted between one communication device and one repeater, the remaining plurality of communication devices perform only PHY layer decoding to determine whether they are physical layer protocol data units transmitted to themselves using the MAC address included in the PLCP header. After determining, the remaining frames may be discarded according to the determination that the physical layer protocol data unit is not transmitted to the physical layer protocol data unit. E _c and E _δ , which are the energy profile when collisions occur and the energy consumption in the idle state, are the same as the above-described formulas applied in the ordinary case.

FIG. 7 is a diagram illustrating a transmission time of a physical layer protocol data unit including lower N bits (eg, N = 18) of a receiver in a PLCP header according to an embodiment of the present invention.

Referring to FIG. 7, T (L, m) 710 and T ′ (L, m) 720 represent the time taken for the physical layer protocol data unit to be transmitted.

5. Energy efficiency of communication device according to an embodiment of the present invention

8 is a view for explaining the energy efficiency of the communication method according to an embodiment of the present invention.

Referring to FIG. 8, a communication device according to an embodiment of the present invention may operate in an IEEE 802.11a PHY layer standard environment using a DCF mode. There are 70 communication devices and the payload size to be transmitted is 1000 bytes. Data transmission, reception, and power consumption in the idle state are as shown in Table 3. 8 is a result of calculating the total energy consumption by changing the value of λ.

Characteristics Value Comments P _ckt 800 mW Circuitry power consumption P _PA = 1 W Power amplifier consumption P _tx P _ckt + P _PA Transmission power consumption P _rx P _ckt Reception power consumption P _idle 300 mW Idle power consumption P _noise -199 dBW Noise power level

FIG. 8 illustrates the results of expressing the results of improving the energy consumption in terms of percentiles when using the physical layer protocol data unit used in the communication apparatus according to an embodiment of the present invention, compared with the case of using the conventional physical layer protocol data unit. Indicates. In this case, FIG. 8 is a result of calculating the efficiency of energy consumed in the entire system, not the efficiency of energy consumed in one link. As described above, the graph in the case where λ is 1 (810) shows the result when the 70 communication devices are all saturated.

When the physical layer protocol data unit used in the communication apparatus according to the embodiment of the present invention is used, energy efficiency of 20% or more can be improved as compared with the case of using the conventional physical layer protocol data unit. This is true not only when the saturated state lambda is 1 (810) but also when the unsaturated state lambda is 0.1 (820).

As described above, the present invention has been described by way of limited embodiments and drawings, but the present invention is not limited to the above embodiments, and those skilled in the art to which the present invention pertains various modifications and variations from such descriptions. This is possible. As described above, the present invention has been described based on the 802.11a standard, but can be applied to other wireless LANs such as 802.11g, 802.11n, and 802.11ac.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

110: first subframe including synchronization information
120: a second subframe including a PHY layer header including a first identifier identifying a receiver
130: third subframe comprising a MAC protocol data unit comprising a second identifier identifying data and a receiver

Claims (15)

A generator configured to generate a physical layer protocol data unit including a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer; And
Transmitter for transmitting the physical layer protocol data unit
Including,
The first subframe
Synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit,
The second subframe
A PHY layer header including a first identifier identifying said receiver,
The third subframe
And a MAC protocol data unit comprising data and a second identifier identifying the receiver.
A receiver configured to receive a physical layer protocol data unit including a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer;
A first decoder to decode the second subframe in the PHY layer;
A determination unit to determine whether to decode the third subframe in the MAC layer using the decoded second subframe;
A second decoding unit configured to decode the third subframe in the MAC layer according to a determination of decoding the third subframe in the MAC layer.
Including,
The first subframe
Synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit,
The second subframe
A PHY layer header including a first identifier identifying said receiver,
The third subframe
And a MAC protocol data unit comprising data and a second identifier identifying the receiver.
4. The method according to any one of claims 1 to 3,
Each of the first identifier and the second identifier
And identify the receiver according to the MAC address of the receiver.
The method of claim 3,
The first identifier is
And identify the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.
4. The method according to any one of claims 1 to 3,
The synchronization information includes any one of the PLCP sublayer preambles of all wireless LAN protocols including the IEEE 802.11a standard protocol,
The PHY layer header further comprises any one of PLCP sublayer headers of all the wireless LAN protocols.
A communication device using a physical layer protocol data unit,
The physical layer protocol data unit is
A first subframe including synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit;
A second subframe including a PHY layer header including a first identifier identifying the receiver; And
A third subframe comprising a MAC protocol data unit comprising data and a second identifier identifying the receiver
Communication device using a physical layer protocol data unit comprising a.
The method according to claim 6,
Each of the first identifier and the second identifier
And a physical layer protocol data unit identifying the receiver according to the MAC address of the receiver.
The method of claim 7, wherein
The first identifier is
And a physical layer protocol data unit identifying the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.
The method according to claim 6,
The synchronization information includes any one of the PLCP sublayer preambles of all wireless LAN protocols including the IEEE 802.11a standard protocol,
And the PHY layer header further comprises any one of PLCP sublayer headers of all the wireless LAN protocols.
Generating a physical layer protocol data unit comprising a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer; And
Transmitting the physical layer protocol data unit
Including,
The first subframe
Synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit,
The second subframe
A PHY layer header including a first identifier identifying said receiver,
The third subframe
And a MAC protocol data unit comprising data and a second identifier identifying the receiver.
Receiving a physical layer protocol data unit comprising a first subframe decoded in a PHY layer, a second subframe decoded in the PHY layer, and a third subframe decoded in a MAC layer;
Decoding the second subframe in the PHY layer;
Determining whether to decode the third subframe in the MAC layer using the decoded second subframe;
Decoding the third subframe at the MAC layer according to a determination to decode the third subframe at the MAC layer.
Including,
The first subframe
Synchronization information for synchronization between a receiver receiving the physical layer protocol data unit and a transmitter transmitting the physical layer protocol data unit,
The second subframe
A PHY layer header including a first identifier identifying said receiver,
The third subframe
And a MAC protocol data unit comprising data and a second identifier identifying the receiver.
The method according to any one of claims 10 and 11,
Each of the first identifier and the second identifier
And identifying the receiver according to the MAC address of the receiver.
The method of claim 12,
The first identifier is
And identifying the receiver according to a predetermined number of lower N bits of the MAC address of the receiver.
The method according to any one of claims 10 and 11,
The synchronization information includes any one of the PLCP sublayer preambles of all wireless LAN protocols including the IEEE 802.11a standard protocol,
The PHY layer header further comprises any one of PLCP sublayer headers of all the wireless LAN protocols.
A computer-readable recording medium having recorded thereon a program for executing the method of any one of claims 10 and 11.

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