JP2007019773A - Transmitter, receiver and communications equipment provided with them - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To lower power consumption, while keeping compatibility with a packet communications system represented by IEEE802.11 Standards. <P>SOLUTION: In communications equipment, in a transmission operation, a MAC layer information part is generated by adding a misdetection code for data immediately in front of the IBSS-ID of a header for the protocol of a MAC layer following a physical layer information part inside a packet, rather than the IBSS-ID inside the header in a frame information generation means 12 of a MAC layer processing part 2, is modulated in a transmission part 7, and is sent out from a transmission/reception antenna 5, together with the physical layer information part. In reception operation, signals from the transmission/reception antenna 5 are demodulated in a reception part 6, the signal analysis of the MAC layer is performed in a frame information acquisition means 8 and the received error code and calculated error code are compared. An operation state control means 9 performs power-saving control, depending on the contents. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a transmission device, a reception device, and a communication device including them, which packetize data regardless of wired radio and perform mutual communication.

  With the development of communication networks, there is a demand for higher functionality of mobile radio terminals typified by mobile phones. However, the high functionality of this portable wireless terminal has resulted in an increase in power consumption and a problem of shortening the driving time. This problem can be solved if a small, light and large capacity battery is obtained, but such a battery has not yet been obtained. For this reason, in order to lengthen the driving time of the portable wireless terminal, power saving of the terminal is essential.

In general, the power-saving technology adopted by terminals is
(1) A method of reducing the power consumption of the circuit itself used for signal processing,
(2) A method of using a sleep state that is used in a notebook type personal computer or the like and is operated only when necessary, and is otherwise suspended.
It is roughly divided into two.

  The power saving of the method (1) can be performed only by the terminal regardless of the wireless communication method, but the power saving of the method (2) needs to comply with the protocol of the wireless communication method. Here, as an example of a typical wireless LAN communication method, a working group 11 (referred to as IEEE802.11 or lower 802.11) of the IEEE802 standardization committee will be described with reference to FIGS.

  9 is an explanatory diagram of the frame structure of the 802.11 standard, FIG. 10 is a block diagram of a conventional communication device, FIG. 11 is a flowchart when the communication device transmits according to the 802.11 standard, and FIG. These are flowcharts when the communication apparatus receives data according to the 802.11 standard.

  In FIG. 9, the information part for the physical layer and the upper medium access control (Media Access Control, hereinafter referred to as MAC) in the one-to-one terminal communication (hereinafter referred to as ad hoc mode) established in the 802.11 standard. ) A packet structure including a layer information part and a reception operation of the terminal will be described.

  First, there is a preamble 101 for physical layer synchronization, followed by a frame start flag called SFD 102, followed by physical layer packet handling information called PLCP header 103. The PLCP header 103 contains the type of physical layer, the symbol rate of the MAC layer information part, and the number of symbols in the MAC layer information part. Further, immediately after the PLCP header 103, CRC16 (104) is added as an error detection code. The above is collectively referred to as a physical layer information section.

  The MAC layer information section follows the PLCP header 103 and the CRC 16 (104). The header 105 for the MAC layer is stored at the top, followed by the data 106 for the MAC layer, and finally the CRC32 (107) is added as an error detection code for the header 105 and the data 106 for the MAC layer. Has been. In the header 105 of the MAC layer, packet handling information for the MAC layer, particularly frame control information 108, packet duration 109, destination address 110, source address 111, independent basic service set identifier (consisting of a plurality of terminals) Network identifier, which is hereinafter referred to as IBSS-ID) 112, and sequence control information 113 are stored.

  As shown in FIG. 10, the communication device that transmits and receives data having the frame structure includes a transmission / reception antenna 205, a transmission / reception switching unit 211, a physical layer processing unit 201, and a MAC layer processing unit 202. The physical layer processing unit 201 includes a reception unit 206 and a transmission unit 2107.

The operation of each part in the transmission operation of this communication apparatus will be described with reference to the flowchart of FIG.
In step S101, the MAC layer processing unit 202 prepares MAC layer data 106 to be transmitted to the destination terminal.
In step S102, the MAC layer processing unit 202 prepares the frame control information 108, the packet duration 109, the destination address 110, and the source address 111.
In step S103, the MAC layer processing unit 202 prepares an IBSS-ID.
In step S104, the MAC layer processing unit 202 prepares the sequence control information 113.

In step S105, the MAC layer processing unit 202 calculates the CRC 32 (107) related to the data prepared in steps S101 to S104. The MAC layer processing unit 202 calculates the MAC layer header 105, the MAC layer data 106, and the CRC 32 (107). The data is transmitted to the transmission unit 207 via the data bus 203.
In step S106, the transmission unit 207 prepares the preamble 101, the SFD 103, and the PLCP header 103.

In step S107, the transmission unit 208 calculates CRC16 (1204) regarding the data prepared in step S106. Thus far, the packet shown in FIG. 7 is created.
In step S108, the transmission unit 207 adds the preamble 101, the SFD 103, the PLCP header 103, and CRC16 (104) to the head of the MAC layer header 105, MAC layer data 106, and CRC32 (107) transmitted in step S105, and performs modulation. Do. The modulated data is transmitted from the transmission / reception antenna 205 via the data bus 203 and the transmission / reception switching unit 211.

The operation of each unit in the reception operation of this communication apparatus will be described with reference to the flowchart of FIG.
In step S201, the transmission / reception switching unit 211 sends the data received from the transmission / reception antenna 205 to the reception unit 206 of the physical layer processing unit 201 via the data bus 203, and the reception unit 206 receives the data physical layer information unit. The CRC 16 is calculated from the received preamble 101, SFD 102, and PLCP header 103. The CRC 16 calculated in step S202 is compared with the received CRC 16 (104). If they match, the process proceeds to step S204, and the continuation of the frame is received. If they do not match, the process proceeds to step S203, and the continuation of the frame is not received, and an error is reported to an upper layer such as the MAC layer.

  In steps S204 to S208, the reception unit 206 receives the frame control information 108, the packet duration 109, the destination address 110, the source address 111, the IBSS-ID 112, the sequence control information 1213, and the MAC layer data 1206 shown in FIG. The data is sent to the MAC layer processing unit 2102 via the data bus 203.

  In the MAC layer processing unit 202, frame control information 108, packet duration 109, destination address 110, source address 111, IBSS-ID 112, sequence from the header of the MAC layer at the head of the symbol sent from the receiving unit 206 The control information 113 is extracted.

  In step S209, the MAC layer processing unit 202 receives the CRC 32 calculated from the received frame control information 108, packet duration 109, destination address 110, source address 111, IBSS-ID 112, sequence control information 113, and MAC layer data 106. The CRC 32 (107) is compared, and if there is an error in the CRC 32 check, the process proceeds to step S210 and the frame is discarded. If it is determined by the CRC 32 check that there is no error, it is determined that the control information and the destination address extracted earlier are valid, and the process proceeds to step S211.

  In step S211, the MAC layer processing unit 202 determines that this packet is of a type acceptable to itself and that the packet is addressed to itself, and processes the symbol in the data part for the MAC layer. Thus, reception of one frame is completed. If the packet is not addressed to itself or is not an acceptable type, the MAC layer processing unit 202 proceeds to step S212 and discards the frame.

  Patent Document 1 exists as an example in which power consumption is reduced by using the frame structure standardized in 802.11 described so far. The frame structure of this Patent Document 1 is shown in FIG. The structure of FIG. 13 is the same as the structure of FIG. 7 except for the MAC layer header 305. In the MAC layer header 305, an extra error detection code 3214 is added compared to the 802.11 standard of FIG. .

In the example of Patent Document 1, the presence / absence of data addressed to the own terminal is determined from the destination address 310 stored in the upper layer header (corresponding to the MAC layer header in FIG. 9) 305, and the own terminal is set as the destination included in the destination address 310. If there is no frame, reception is stopped for that frame, and power is not turned on until the start time of the next frame of the frame, thereby reducing the power consumption of the receiving unit.
JP 2000-261462 A

  However, in the example of Patent Document 1, an error detection code 3214 is added in comparison with the 802.11 standard, so that it is compatible with a communication device using the 802.11 standard that is currently available to consumers. They cannot communicate with each other.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a transmission apparatus, a reception apparatus, and a communication apparatus including the transmission apparatus that can reduce power consumption while maintaining compatibility with a packet communication system represented by the IEEE 802.11 standard. is there.

In a packet communication system in which information to be transmitted is packetized and intercommunication is performed, the present invention provides a protocol layer header higher than the physical layer after the physical layer information storage unit in the packet in the packet. , A transmission device for transmitting a signal by adding an error detection code for the header at the end of the header,
The medium is included in a medium access control layer header part that transmits control information related to the medium access control layer data part, and the medium is assigned to the time domain to which an independent basic service set identifier that is an identifier of a network composed of a plurality of terminals is assigned. An error detection code for detecting an error in the access control header portion is calculated and assigned, and frame information generation means for generating a frame, and transmission means for transmitting a signal including the error detection code are provided. .

  In the transmission device, the error detection code includes frame control information of a medium access control layer data part, a packet duration of a medium access control layer data part, a destination address, and a transmission source included in the header part of the medium access control layer The frame information generating means is configured to detect the error detection code from information regarding the frame control information, the packet duration, the destination address, and the source address. It is characterized by calculating.

  In the transmitter, the error detection code is an error correction code.

Further, the present invention provides a packet communication system for packetizing information to be transmitted and performing mutual communication, and after a physical layer information storage unit in a packet in a packet, a header for a protocol in a layer higher than the physical layer is provided. A receiving device for receiving a signal by placing an error detection code for the header at the end of the header,
The medium is included in a medium access control layer header part that transmits control information related to the medium access control layer data part, and the medium is assigned to the time domain to which an independent basic service set identifier that is an identifier of a network composed of a plurality of terminals is assigned. A receiving means for receiving a signal having a frame structure to which an error detection code for detecting an error in the access control header portion is assigned, and an error code received by the receiving means by calculating the error detection code from the received signal. And determining means for determining whether or not the received error code matches the calculated error code, and if not, stops receiving information that arrives after receiving the error code And a control means.

  In the receiving device, the error detection code is included in the medium access control layer header part, the frame control information of the medium access control layer data part, the packet duration of the medium access control layer data part, the destination address, and the transmission source This is a code for detecting an error relating to an address, and the determination means calculates the error detection code from information relating to the frame control information, the packet duration, the destination address, and the source address. It is characterized by that.

  In the receiving apparatus, the error detection code is an error correction code.

  Further, in the receiving device, the determining means determines whether or not the received destination address is addressed to itself, and the control means, after the error code is received, when the destination address is not addressed to itself. The reception of incoming information is stopped.

  In the receiving apparatus, the control means maintains the reception stop state at least until the next frame arrives.

  In addition, the present invention is a communication device including the transmission device and the reception device.

In the communication device,
In order to determine whether the communication partner is the receiving device, the transmitting device may send a survey packet,
The survey packet may be received by the reception device, and a response packet may be transmitted if the transmission device can accept the packet,
If the survey packet is transmitted by the transmission device and a response packet is received from the transmission destination terminal by the reception device, then an error in the medium access control header portion is displayed in the time domain to which the independent basic service set identifier is assigned. A packet having a frame structure to which an error detection code for detecting a frame is assigned may be transmitted.

  The present invention is a wireless packet communication system that packetizes data to be transmitted using a wireless medium conforming to the 802.11 standard and performs mutual communication in an ad hoc mode, and continues to an information part for a physical layer in the packet. Instead of the IBSS-ID in the header for the MAC layer protocol, an error detection code is added to the data up to immediately before the IBSS-ID in the header. Then, when receiving a packet, the protocol of the upper layer of the physical layer checks the address and control information in the header, confirms that the address and control information are valid by the error detection code, and the address Is determined not to be addressed to itself or to control information that is not acceptable to the user, an instruction to shift to the power saving operation state is sent to the receiving unit.

  Further, according to the present invention, when the error detection code added to the MAC layer header confirms that the header is invalid, an instruction to shift to the power saving operation state is sent to the receiving unit. .

  According to the present invention, when the error detection code added to the header of the MAC layer is read, it is possible to determine whether the information in the header is valid or invalid due to an error. If it is an invalid packet, an instruction to shift to the power saving operation state can be issued to the receiving unit at that time, and thereafter the low power consumption state can be maintained until the next packet in both the physical layer and the MAC layer. Thus, the power consumption can be greatly reduced, and a communication device capable of reducing the power consumption while maintaining the compatibility with the packet communication system represented by the IEEE 802.11 standard becomes possible.

Embodiments of the present invention will be described below with reference to the drawings.
Here, as the definition of the word,
Active operation state: Operation state for continuous transmission or continuous reception,
・ Power-saving operation state: An operation state that reduces power consumption by stopping the power supply of each module, lowering the operating frequency, reducing the power supply voltage or current, etc.
And

In the description of the present embodiment, description is made along the ad hoc mode of the 802.11 standard for the following two reasons.
(1) While the IBSS-ID is always the same value in the 802.11 standard, the error detection code replaced according to the present invention is almost always fluctuated from frame to frame. For this reason, in the infrastructure mode in which an unspecified number of terminals communicate, communication cannot be performed simply by replacing them. On the other hand, in the ad hoc mode, which is one-to-one communication, the IBSS-ID only needs to have the same value at the ends communicating with each other. Furthermore, it is convenient to use the ad hoc mode considering that the error detection code has the same value as long as no error is detected even if the value varies for each frame.
(2) Since the network can be identified by the destination address and the source address in the MAC layer header, these can be used instead, which is convenient.
Therefore, it goes without saying that the present invention is not limited to the 802.11 standard ad hoc mode, but can be applied to any communication form having a similar frame structure.

  FIG. 1 is a block diagram showing an embodiment of a packet communication system according to the present invention. The packet communication system according to the present invention can be roughly classified into a physical layer processing unit 1, a MAC layer processing unit 2, a data bus 3 between the physical layer and the MAC layer, a physical layer control line 4 from the MAC layer, and a transmission / reception antenna. 5 and a transmission / reception switching unit 11. The physical layer processing unit 1 includes a receiving unit 6 and a transmitting unit 7. The MAC layer processing unit 2 includes a frame information acquisition unit 8, an operation state control unit 9, a frame information transmission line 10, a frame information generation unit 12, and a frame information determination unit 13.

  FIG. 2 is a packet structure diagram of the present invention. Most of the portions are the same as those in FIG. 9, reference numerals 101 to 107 correspond to reference numerals 21 to 27, and reference numerals 108 to 111 and 113 correspond to reference numerals 28 to 31 and 33. The changed part is the error detection code 32 for the MAC layer header up to immediately before being added instead of the IBSS-ID 112 of the MAC layer header 105. The IBSS-ID 112 is a 48-bit value such as “CBA0043210FE” (hexadecimal number), and the error detection code 32 is a 48-bit value such as “9A5C0712BBF7” (hexadecimal number) when the CRC48 is employed. Replacement is possible.

Hereinafter, an outline of the operation of the communication apparatus of FIG. 1 will be described.
In this communication apparatus, at the time of transmission operation, the frame information generation means 12 of the MAC layer processing unit 2 generates the MAC layer information unit having the frame structure shown in FIG. The data is transmitted from the transmission / reception antenna 5 together with the transmission data.

  During the reception operation, the signal received from the transmission / reception antenna 5 (the signal having the frame structure of FIG. 2) is sent to the reception unit 06 in the physical layer processing unit 1 via the transmission / reception switching unit 11. The signal is demodulated by the receiving unit 6, and the MAC layer information unit is sequentially sent to the MAC layer processing unit 102. The frame information acquisition unit 108 extracts the MAC layer header 305 and sends it to the frame information determination unit 113, where signal analysis is performed, and the received error code is compared with the calculated error code to determine a match / mismatch. Each information of the header acquired by the frame information acquisition unit 8 is sent to the operation state control unit 9 via the frame information transmission line 10, and the determination result is sent from the frame information determination unit 13 to the operation state control unit 9. Depending on the contents, power saving control of each part is performed. Further, the MAC layer data 26 output from the receiving unit 6 is sent to a higher layer processing unit as necessary.

  Although FIG. 1 is described as a communication device in which a reception unit and a transmission unit are integrated, it is not integrated like a reception device that includes only a reception unit or a transmission device that includes only a transmission unit. Also good.

Next, a detailed operation including the power saving operation of the communication apparatus of FIG. 1 will be described.
In the operation at the time of transmission, the frame information generation means 12 of the MAC layer processing unit 2 obtains the error detection code 32 from the frame control information 8, the packet duration 29, the destination address 30, and the transmission source address 31, which are transmitted contrary to the reception. The frame structure of the MAC layer information part is generated by calculation and sent to the transmission part 7. The MAC layer information unit is modulated by the transmission unit 7 and transmitted from the transmission / reception antenna 5 via the transmission / reception switching unit 11 as transmission data together with the physical layer information unit. Except when the terminal itself transmits data, power consumption can be reduced by sending an instruction from the operation state control means 9 to the transmission unit 7 to shift to the power saving operation state.

  FIG. 3 is a flowchart for transmitting the packet structure of the present invention. Most of the parts are the same as those in FIG. 11, and steps S1, S2, and S4 to S8 correspond to steps S101, S102, and S104 to S108.

  3 differs from FIG. 11 in that the IBSS-ID 112 is prepared in step S103 in the prior art, whereas the present invention calculates and prepares the MAC layer header error detection code 32 up to the previous step in S103. is there. Thereafter, data is prepared in steps S104 to S107 as in the prior art, and the packet shown in FIG. 2 is created and transmitted in step S108.

Next, the reception operation will be described.
FIG. 4 is a flowchart showing the operation of each part of the communication apparatus when receiving the packet of the present invention.

  In step S <b> 11, during a reception operation, a signal received from the transmission / reception antenna 5 is sent to the reception unit 6 in the physical layer processing unit 1 via the transmission / reception switching unit 11. When receiving a packet, the steps up to error detection of the physical layer header by the CRC 16 in step S12 are the same as those in the 802.11 standard technique. If no error is detected in the CRC16 check, the process proceeds to step S14, where the receiving unit 6 starts demodulating the MAC layer header 25 and sequentially transfers the obtained symbols to the MAC layer processing unit 2.

  In step S14, the frame information acquisition unit 8 of the MAC layer processing unit 2 transmits the frame control information 28, the packet duration 29, the destination address 30, and the transmission from the header of the MAC layer at the head of the symbol sent from the physical layer. The original address 31 is received.

  In step S16, the frame information acquisition means 8 in the MAC layer calculates the error detection code of the frame control information 28, the packet duration 29, the destination address 30, and the transmission source address 31. Next, the frame information determination means 13 compares the received error detection code 32 with the calculated error detection code, and determines a match / mismatch. If the two error detection codes do not match as a result of the determination, it is found that the MAC layer header before the error detection code 32 is broken due to an error occurring somewhere in the transmission path, so that step S17 The operation state control means 9 can instruct the receiving unit 6 and the frame information acquisition means 8 to stop receiving and shift to the low power consumption state.

  If the two error detection codes match as a result of the comparison in step S16, it is known that there is no error in the MAC layer header 25, so that various information extracted from the header is also guaranteed to be correct. . Therefore, the process proceeds to step S18 and shifts to a determination stage using the various information.

  Information such as control information, packet duration, and destination address has already been extracted from the header by the frame information acquisition means 8. In step S19, the frame information determination means 13 checks the destination address 30 therein to determine whether the packet is addressed to itself. The determination result is transmitted to the operation state control unit 9, and the operation state control unit 9 instructs the reception unit 6 to continue reception if it is addressed to itself, and proceeds to step S20.

However, if the destination address 30 does not point to itself, it is meaningless to continue receiving more than this, so that the operation state control means 9 proceeds to step S19 and the reception unit 6 and the frame information acquisition means 10 receive it. Is issued and an instruction is issued to shift to a low power consumption state.
Further, even if it is found from the control information that the packet is not related to itself, it is meaningless to continue receiving more than this, so the process proceeds to step S19 and reception to the receiving unit 6 and the frame information acquiring means 10 is performed. Stop and issue an instruction to shift to a low power consumption state.

  If the frame control information 28 and the destination address 30 indicate that the packet being received is for broadcast, reception may have to be continued. Furthermore, the existing CRC can be used as the error detection code 32 for the MAC layer header used in the above, but other check codes may be used. Further, if an error correction code such as a Reed-Solomon code is used, the error can be corrected, so that it is not necessary to send and receive the same data again, and the power consumption is further reduced.

When the error correction code is a block code such as a Hamming code, a BCH code, or a Reed-Solomon code, a block code having the same number of bytes may be inserted instead of the IBSS-ID as described above.
When the error correction code uses a convolutional code such as a Viterbi algorithm or a punctured turbo code, the frame control information 28, the packet duration 29, the destination address 30, and the transmission source address 31 are convolutionally encoded. Redundant bits required at that time use the area of the error detection code 32.
The error correction process is performed by the frame information determination unit 13.

  If the result of determination in step S18 is that it is addressed to you, you will continue to step S22. In step S23, the frame information determination unit 13 compares the received CRC layer header 25 and the CRC 32 calculated from the MAC layer data 26 with the received CRC 32 (27), and determines that the received data is valid if they match. End this frame. If not, the process proceeds to step S24, and this frame is discarded. This is the operation for reception.

  When a device having the function of the present invention needs to communicate with a device of the 802.11 standard that does not have the function, the IBSS- which is determined by the user instead of the error detection code 32 in the frame of FIG. An ID can be added.

Next, a procedure for switching from the communication system compliant with the 802.11 standard to the communication system of the present invention will be described with reference to FIG.
A plurality of devices start communication with each other. As shown in step S31, these devices initially communicate by a method based on the 802.11 standard, including devices that support the communication method of the present invention. Here, in the device having the function of the present invention, after an arbitrary time set by the designer, the device having the function of the present invention transmits a probe request. The probe request is a survey packet transmitted to inquire about the presence or absence of a wireless device present in the vicinity of a certain terminal, and the frame structure in the 802.11 standard is the same as that shown in FIG. The terminal that has received the probe request is supposed to return a probe response thereto. A probe response is a response packet indicating its presence by responding to a probe request.

  However, the frame structure of the probe request transmitted here is the frame structure of the present invention shown in FIG. Therefore, if the device that has received the probe request has the function of the present invention, it is possible to return a response to the probe request. It is judged that it is not and will be ignored. In step S33, the frame information determination unit 13 determines whether there is a probe response.

If there is a probe response, the frame information determination means 113 determines that the counterpart device has the function of the present invention, proceeds to step S34, and changes from the next communication with the device to the communication operation of the present invention. .
If there is no probe response, it is determined that the counterpart device does not have the function of the present invention, so that the process proceeds to step S35, and communication conforming to the 802.11 standard is performed as before.
When a new device participates in communication, it is only necessary to determine whether or not the device has the function of the present invention by transmitting a probe request with the frame structure of the present invention.

  As described above, according to the present invention, when the error detection code 32 included in the header of the MAC layer is read, whether the information in the header is valid or invalidated due to an error. Judgment is possible. Therefore, if it is an unnecessary or invalid packet, it is possible to instruct the receiving unit 6 and the frame information acquiring unit 8 to stop at that point, and the physical packet processing unit 1 and the MAC layer processing unit 2 thereafter send the next packet. Since the low power consumption state can be maintained until this time, the power consumption can be greatly reduced as compared with the case where reception is continued up to the last CRC 32 of the packet as in the 802.11 standard.

For example, consider a case where 2312-byte MAC layer data is received at 1 Mbps in the IEEE802.11b standard long frame format (FIGS. 6 and 7). For technology according to the 802.11b standard,
(Power consumption per unit time) x (Frame duration)
= 2.6 (W) × [192 μs + 176 μs + 18544 μs]
= 13.7 (μWh)

In contrast, in the present invention,
(Power consumption per unit time) x (Frame duration)
= 2.6 (W) × [192 μs + 176 μs] +1.0 (W) × 18544 (μs)
= 5.42 (μWh)
Thus, according to the present invention, the power consumption per frame can be reduced by about 60.4%.
In addition, in the radio technology according to the present embodiment, for example, the receiving unit 6 in particular has an advantage that the product life is extended because the accumulated time for energization is shortened.

  Furthermore, when an error correction code is used for the error detection code 312, the number of retransmission processes is reduced by the number of frames that can be error corrected, so that the communication efficiency is higher than in the case of the error detection code. Therefore, the communication speed increases and the power consumption of the device is reduced on both the transmission side and the reception side. How much power consumption is reduced depends on the number of error-corrected frames, but the number is determined by various factors such as the state of the transmission path, the type of error correction code, and the frame size. Omitted.

  As another effect, it can be used without changing hardware represented by an ASIC (Application Specific Integrated Circuit) for realizing wireless communication of the existing 802.11 standard. The reason is as follows. In the 802.11 standard frame structure, the operation of extracting the source address, the destination address, and the IBSS-ID from the frame is usually performed by hardware because it is a fixed operation and is fast. However, since the values of the transmission source address, the transmission destination address, and the IBSS-ID are changed by the device itself or the user of the device, processing of these extracted values is performed by software. Here, the present invention has the compatibility that the number of bytes of the frame structure of the 802.11 standard is the same, so that it is possible to perform the operation of extracting the value by hardware as before. In the unlikely event that the number of bytes is different, there is a problem that the extracted value is not correct as the value is shifted. Therefore, the conventional hardware can be used as it is only by changing the software, and the present invention can be implemented.

  In addition, since communication is performed according to the 802.11 standard at the start of communication and the communication method of the present invention is performed only with a device that has been identified as a device having the functions of the present invention, Compatibility is maintained. Therefore, communication with many existing devices is also possible.

  An example of the utilization form of the present invention is shown in FIG. Reference numeral 41 denotes an electronic device such as a television. Reference numeral 42 denotes an information storage device such as a video recorder or a TV tuner. 43 is a communication module of the present invention. 44 is an antenna. 45 is a rechargeable battery. Reference numeral 46 denotes information such as video and data to be displayed on a television or the like. Reference numeral 47 denotes data to the information storage device such as channel instructions, settings, and requests.

  When the user of the electronic device 41 changes the viewing channel, the change request is sent to the information storage device 42 via the communication module of the present invention. The information storage device 42 transmits information such as video and audio of the channel corresponding to the sent change request to the electronic device 41 via the communication module.

  Even if the electronic device 41 and the information storage device 42 are in different rooms, the electronic device 41 can be connected to the information storage device 402 as long as the attached communication module of the present invention can communicate with each other without being troubled with the routing of the cord. You can watch and listen to recorded videos and TV broadcasts. By driving the battery, the electronic device 41 is free from any code restrictions. By reducing the power consumption of the communication module of the present invention, the viewable time of the electronic device 41 becomes longer and convenience can be provided to the user.

  As mentioned above, although demonstrated along this Embodiment, it cannot be overemphasized that this invention is not limited to these examples, and various deformation | transformation are possible. The communication technology according to the present embodiment can be applied to various communication devices regardless of wireless or wired.

  Further, in applications where wired cables have been used for signal transmission so far, the reduction in power consumption of the present invention is effective for the power supply problem that becomes a problem when the wired cables are replaced with radio. Specific applications include communication in LANs such as personal computers, mobile phones, IP phones, game machines, and transmission of video and audio.

It is a block diagram which shows embodiment of the packet communication system in this invention. It is a figure explaining the frame structure of this invention. It is a flowchart which shows the operation | movement at the time of transmitting the flame | frame of this invention. It is a flowchart which shows the operation | movement at the time of receiving the flame | frame of this invention. It is a flowchart which shows the operation | movement at the time of switching from the communication based on 802.11 specification to the communication of this invention. It is a comparison figure with the 802.11 standard technique at the time of 1 frame reception for demonstrating the power saving effect of this invention. It is the power consumption of each part for demonstrating the power saving effect of this invention. It is an example of the utilization form of this invention. It is a frame structure of the 802.11 standard. It is a block diagram which shows the conventional communication apparatus. It is a flowchart at the time of transmitting 802.11 standard. It is a flowchart at the time of receiving the 802.11 standard. It is a frame structure figure proposed by patent documents 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Physical layer processing part 2 MAC layer processing part 3 Data bus 4 Control line 5 Transmission / reception antenna 6 Reception part 7 Transmission part 8 Frame information acquisition means 9 Operation state control means 10 Frame information transmission line 11 Transmission / reception switching part 12 Frame information generation means 13 Frame information determination means 21 Preamble 22 SFD
23 PLCP header 24 CRC16
25 MAC layer header 26 MAC layer data 27 CRC32
28 Frame control information 29 Packet duration 30 Destination address 31 Source address 32 MAC layer header error detection code 33 Sequence control information 41 Video display device 42 Video information storage device 43 Communication module 44 of the present invention Antenna 45 Battery 46 Video display device Information to 47 Information to video information storage device 101 Preamble 102 SFD
103 PLCP header 104 CRC16
105 MAC layer header 106 MAC layer data 107 CRC32
108 Control information 109 Packet duration 110 Destination address 111 Source address 112 Independent basic service set identifier (IBSS-ID)
113 Sequence control information 301 Preamble 302 SFD
303 PLCP header 304 CRC16
305 MAC layer header 306 MAC layer data 307 CRC32
308 Control information 309 Packet duration 310 Destination address 311 Source address 312 Independent basic service set identifier (IBSS-ID)
313 Sequence control information 314 Error detection code for MAC layer header

Claims (12)

In a packet communication system that packetizes information to be transmitted and performs mutual communication, a header for a protocol in a layer higher than the physical layer is arranged after the physical layer information storage unit in the packet in the packet, A transmission device that adds an error detection code to the header at the end and transmits a signal,
The medium is included in a medium access control layer header part that transmits control information related to the medium access control layer data part, and the medium is assigned to the time domain to which an independent basic service set identifier that is an identifier of a network composed of a plurality of terminals is assigned. An error detection code for detecting an error in the access control header part is calculated and assigned, and frame information generating means for generating a frame;
A transmission apparatus comprising: transmission means for transmitting a signal including the error detection code. The error detection code detects an error related to frame control information of the medium access control layer data part, a packet duration of the medium access control layer data part, a destination address, and a source address included in the header part of the medium access control layer. Is a code for
2. The frame information generation unit calculates the error detection code from information on the frame control information, the packet duration, the destination address, and the transmission source address. Transmitter.   The transmission apparatus according to claim 1, wherein the error detection code is an error correction code. In a packet communication system that packetizes information to be transmitted and performs mutual communication, a header for a protocol in a layer higher than the physical layer is arranged after the physical layer information storage unit in the packet in the packet, A receiver for receiving a signal by adding an error detection code to the header at the end,
The medium is included in a medium access control layer header part that transmits control information related to the medium access control layer data part, and the medium is assigned to the time domain to which an independent basic service set identifier that is an identifier of a network composed of a plurality of terminals is assigned. Receiving means for receiving a signal having a frame structure assigned with an error detection code for detecting an error in the access control header part;
A determination unit that calculates the error detection code from the received signal, compares the error code received by the reception unit with the calculated error code, and determines whether or not the received error code matches the calculated error code When,
And a control unit for stopping reception of information that has arrived after reception of the error code if they do not match. The error detection code detects an error related to frame control information of the medium access control layer data part, a packet duration of the medium access control layer data part, a destination address, and a source address included in the header part of the medium access control layer. Is a code for
5. The transmission according to claim 4, wherein the determination unit calculates the error detection code from information regarding the frame control information, the packet duration, the destination address, and the transmission source address. apparatus.   The transmission apparatus according to claim 4, wherein the error detection code is an error correction code. The determination means determines whether the received destination address is addressed to itself;
The receiving apparatus according to claim 4, wherein the control unit stops receiving information that has arrived after receiving the error code when the destination address is not addressed to itself.   The receiving apparatus according to claim 4, wherein the control unit maintains the reception stop state at least until a next frame arrives. A transmission device according to any one of claims 1 to 3,
A receiving device according to any one of claims 4 to 8,
A communication device comprising:   The communication apparatus according to claim 9, wherein an inquiry packet is transmitted by the transmission apparatus in order to determine whether a communication partner is the reception apparatus.   The communication device according to claim 9, wherein the receiving device receives the investigation packet, and transmits the response packet if the transmitting device can accept the packet.   If the survey packet is transmitted by the transmission device and a response packet is received from the transmission destination terminal by the reception device, then an error in the medium access control header portion is displayed in the time domain to which the independent basic service set identifier is assigned. The communication apparatus according to claim 9, wherein a packet having a frame structure to which an error detection code for detecting an error is assigned is transmitted.

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