Communication apparatus, communication method, and communication system

• US 20050165950A1
• Filed: 01/06/2005
• Published: 07/28/2005
• Est. Priority Date: 01/09/2004
• Status: Active Grant

• Current Assignee: Palmira Wireless AG
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Takagi, Masahiro, Utsunomiya, Yoriko, Nishibayashi, Yasuyuki
• Granted Patent: US 7,496,076 B2
• Time in Patent Office: Days
• US Class Current: 709/236
• CPC Class Codes: H04L 1/1607 Details of the supervisory signal
• CPC Class Codes: H04L 1/1614 using bitmaps
• CPC Class Codes: H04L 12/413 with random access, e.g. carrier-sense multiple-access with collision detection [CSMA-CD]
• CPC Class Codes: H04L 12/46 Interconnection of networks
• CPC Class Codes: H04L 12/66 Arrangements for connecting between networks having differing types of switching systems, e.g. gateways
• CPC Class Codes: H04L 2101/622 Layer-2 addresses, e.g. medium access control [MAC] addresses
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers
• CPC Class Codes: H04L 69/323 in the physical layer [OSI layer 1]
• CPC Class Codes: H04L 69/324 in the data link layer [OSI layer 2], e.g. HDLC
• CPC Class Codes: H04W 28/06 Optimizing the usage of the radio link, e.g. header compression, information sizing , discarding information system modifying transmission characteristic according to link quality by modifying frame length H04L1/0007; dynamic adaptation of the packet size for flow control or congestion control H04L47/365
• CPC Class Codes: H04W 28/065 using assembly or disassembly of packets
• CPC Class Codes: H04W 28/14 using intermediate storage
• CPC Class Codes: H04W 52/0203 in the radio access network or backbone network of wireless communication networks
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: Y02B 70/30 Systems integrating technologies related to power network operation and communication or information technologies for improving the carbon footprint of the management of residential or tertiary loads, i.e. smart grids as climate change mitigation technology in the buildings sector, including also the last stages of power distribution and the control, monitoring or operating management systems at local level
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A physical frame is constructed, the physical frame including a medium access control super-frame payload which in turn includes a plurality of medium access control frames. With respect to the constructed physical frame, virtual carrier sense information is set in the plurality of medium access control frame so that a result of carrier sense is identical to another by virtual carrier sense based on the plurality of medium access control frames in the medium access control super-frame payload. The physical frame in which the virtual carrier sense information has been set is transmitted to a destined communication apparatus.

Claims

1. A communication apparatus comprising:

a physical frame construction device configured to construct a physical frame having a medium access super-frame payload which includes a plurality of medium access control frames;

a first setting device configured, with respect to the physical frame constructed by the physical frame construction device, to set virtual carrier sense information in said plurality of medium access control frames so that a result of the carrier sense is identical to another even by a virtual carrier sense based on the plurality of medium access control frames in the medium access control super-frame payload; and

a transmission device configured to transmit a physical frame in which virtual carrier sense information has been set by the first setting device to a destined communication apparatus.

2. A communication apparatus according to claim 1, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

the first setting device is configured to compute the duration from a time point following an end of the last medium access control frame of medium access control frames included in the medium access control super-frame payload to an end time point of the duration, and to set the duration field values included in said plurality of medium access control frames.

3. A communication apparatus according to claim 1, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

the first setting device is configured to compute the duration from a time point following an end of the last medium access control frame of a plurality of medium access control frames set by the first setting device to an end time point of the duration, and to set the duration field values included in said plurality of medium access control frames.

4. A communication apparatus according to claim 1, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

the first setting device is configured to compute the duration from a time point following an end of the physical frame to an end time point of the duration, and to set the field values included in said plurality of medium access control frames.

5. A communication apparatus according to claim 1, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

the first setting device is configured, with respect to each of a plurality of medium access control frames of said plurality of medium access control frames, to compute the duration from a time point following an end of the medium access control frame so that an end time point of the duration becomes identical to another, and to set the duration field included in the medium access control frame.

6. A communication apparatus according to claim 1, comprising:

a device configured to add an error detection code to each of said plurality of medium access control frames in order to detect an error which occurs with a header or a payload of each of said plurality of medium access control frames and thereby to specify a medium access control frame according to detection of the error.

7. A communication apparatus comprising:

a receiving device configured to receive a physical frame having a medium access control super-frame payload which includes a plurality of medium access control frames;

an acquisition device configured to acquire virtual carrier sense information from at least one medium access control frame of a plurality of medium access control frames included in a medium access control super-frame payload of a physical frame received by the receiving device; and

a device configured to specify a duration in which a communication medium is virtually occupied based on the virtual carrier sense information acquired by the acquisition device, and configured to wait for transmission of a frame onto the communication medium in the duration.

8. A communication apparatus according to claim 7, further comprising:

a device configured to set a duration in which the communication medium is virtually occupied, with a start time as a receiving end time point of the last medium access control frame included in the medium access control super-frame payload of the physical frame received by the receiving device, and with an end time as a time point corresponding to an end of the duration.

9. A communication apparatus according to claim 7, further comprising:

a device configured to set a duration in which the communication medium is virtually occupied, with a start time as a receiving end time point of the physical frame received by the receiving device, and with an end time as a time point corresponding to an end of the duration.

10. A communication apparatus according to claim 7, further comprising:

a device configured to set a duration in which the communication medium is virtually occupied, with a start time as a receiving end time point of any one of the medium access control frame included in the medium access control super-frame payload of the physical frame received by the receiving device, and with an end time as a time point corresponding to an end of the duration computed from the virtual carrier sense information included in the medium access control frames.

11. A communication apparatus according to claim 7, further comprising:

a power saving control device configured, in the case where the physical frame received by the receiving device is a physical frame destined to another communication apparatus, to set the communication apparatus at a power saving state in the duration.

12. A communication method comprising:

constructing a physical frame having a medium access super-frame payload which includes a plurality of medium access control frames;

with respect to the physical frame, setting virtual carrier sense information in said plurality of medium access control frame so that a result of the carrier sense is identical to another even by a virtual carrier sense based on the plurality of medium access control frames in the medium access control super-frame payload; and

transmitting a physical frame in which virtual carrier sense information has been set by the setting to a destined communication apparatus.

13. A communication method according to claim 12, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

wherein the setting includes computing the duration from a time point following an end of the last medium access control frame of medium access control frames included in the medium access control super-frame payload to an end time point of the duration, and setting the duration field values included in said plurality of medium access control frames.

14. A communication method according to claim 12, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

wherein the setting includes computing the duration from a time point following an end of the last medium access control frame of medium access control frames set by the setting to an end time point of the duration, and setting the duration field values included in said plurality of medium access control frames.

15. A communication method according to claim 12, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

wherein the setting includes computing the duration from a time point following an end of the physical frame to an end time point of the duration, and setting the field values included in said plurality of medium access control frames.

16. A communication method according to claim 12, wherein the virtual carrier sense information includes a duration field value which represents a duration for virtually occupying a communication medium, and

with respect to each of a plurality of medium access control frames of said plurality of medium access control frames, the setting includes computing the duration from a time point following an end of the medium access control frame so that an end time point of the duration becomes identical to another, and setting the duration field included in the medium access control frame.

17. A communication method according to claim 12, comprising:

adding an error detection code to each of said plurality of medium access control frames in order to detect an error which occurs with a header or a payload of each of said plurality of medium access control frames and thereby to specify a medium access control frame according to detection of the error.

18. A communication method comprising:

receiving a physical frame having a medium access control super-frame payload which includes a plurality of medium access control frames;

acquiring virtual carrier sense information from at least one medium access control frame of a plurality of medium access control frames included in a medium access control super-frame payload of a physical frame received; and

specifying a duration in which a communication medium is virtually occupied based on the virtual carrier sense information acquired, and waiting for transmission of a frame onto the communication medium in the duration.

19. A communication method according to claim 18, further comprising:

setting a duration in which the communication medium is virtually occupied, with a start time as a receiving end time point of the last medium access control frame included in the medium access control super-frame payload of the physical frame received, and with an end time as a time point corresponding to an end of the duration.

20. A communication method according to claim 18, further comprising:

setting a duration in which the communication medium is virtually occupied, with a start time as a receiving end time point of the physical frame received, and with an end time as a time point corresponding to an end of the duration.

21. A communication method according to claim 18, further comprising:

setting a duration in which the communication medium is virtually occupied, with a start time as a receiving end time point of any one of the medium access control frame included in the medium access control super-frame payload of the physical frame received, and with an end time as a time point corresponding to an end of the duration computed from the virtual carrier sense information included in the medium access control frames.

22. A communication method according to claim 18, further comprising:

setting the communication apparatus at a power saving state in the duration, in the case where the physical frame received is a physical frame destined to another communication apparatus.

25. A communication system according to claim 22, wherein, when the retransmission device generates a medium access control super-frame payload of a physical frame to be retransmitted, a transmission data length relevant to the medium access control frame specified by the specifying device is set to 0 without changing the arrangement of the plurality of medium access control frames included in the medium access control super-frame payload of the physical frame transmitted by the transmission device.

26. A communication system according to claim 25, wherein, when the retransmission device generates a medium access control super-frame payload of a physical frame to be retransmitted, and when a medium access control frame whose data length is 0 exists at the beginning of the medium access control super-frame payload, the subsequent medium access control frames are sequentially stored so that a frame whose data length is not 0 is at the beginning thereof.

27. A communication system according to claim 26, wherein the first communication apparatus further comprises a storage which stores medium access control frames to be retransmitted in order, and

when the retransmission device generates a medium access control super-frame payload of a physical frame to be retransmitted, another medium access control frame to be retransmitted to the second communication apparatus is stored in the storage, and, when a free space for a medium access control frame which can be further stored exists in the medium access control super-frame payload of the physical frame to be retransmitted, the medium access control frames stored in the storage are read out in order from a lowest frame, and the read-out frames are sequentially stored from the beginning of the free space.

23. A communication system having a first communication apparatus which corresponds to a transmission source, a second communication apparatus which corresponds to a destination;

a third communication apparatus which does not come under the destination, and a communication medium to which the communication apparatuses are connectable, wherein

the first communication apparatus comprises;

a physical frame construction device configured to construct a physical frame having a medium access control super-frame payload which includes a plurality of medium access control frames;

a first setting device configured, with respect to the physical frame constructing by the physical frame construction device, to set virtual carrier sense information in said plurality of medium access control frames so that a result of the carrier sense is identical to another even by a virtual carrier sense based on the plurality of medium access control frames in the medium access control super-frame payload; and

a transmission device configured to transmit a physical frame in which the virtual carrier sense information has been set by the first setting device to the second communication apparatus,

the second communication apparatus comprises;

a receiving device configured to receive the physical frame transmitted from the communication apparatus;

an acquisition device configured to acquire virtual carrier sense information from at least one medium access control frame of the plurality of medium access control frames included in the medium access control super-frame payload of the physical frame received by the receiving device; and

a device configured to specify a duration in which the communication medium can be occupied, based on the virtual carrier sense information acquired by the acquisition device, and

the third communication apparatus comprises;

a receiving device configured to receive the physical frame transmitted to the second communication apparatus;

an acquisition device configured to acquire virtual carrier sense information from at least one medium access control frame of the plurality of medium access control frames included in the medium access control super-frame payload of the physical frame received by the receiving device; and

a device configured to specify a duration in which the communication medium is virtually occupied, based on the virtual carrier sense information acquired by the acquisition device, and to wait for transmission of a frame onto the communication medium in the duration.

24. A communication system according to claim 23, wherein the second communication apparatus comprises:

a device configured, with respect to delivery response information including a plurality of flags which correspond to the number of medium access control frames included in a medium access control super-frame payload of a physical frame received by at least receiving device, to set each flag in accordance with an arrangement of medium access control frames included in the medium access control super-frame payload and based on whether or not reception has been successfully carried out for each of the medium access control frames; and

a device configured to transmit the delivery response information after set to the first communication apparatus, and

wherein the first communication apparatus comprises;

a device configured to receive the delivery response information;

a specifying device configured to specify a frame which has been successfully received by the second communication apparatus in accordance with an arrangement of a plurality of flags of the received delivery response information and an arrangement of a plurality of access control frames included in a medium access control super-frame payload of a physical frame transmitted by the transmission device; and

a retransmission device configured, in the case where there exists a frame which cannot be specified to have been successfully delivered by the specifying device, to construct a physical frame having a medium access control payload which includes one or more medium access control frames not specified by the specifying device from among the plurality of access control frames included in the medium access control super-frame payload of the physical frame transmitted by the transmission device.

28. A communication system according to claim 24, wherein, with respect to a medium access control frame to be retransmitted to the second communication apparatus, even if a predetermined number of retransmissions to the second communication apparatus is carried out, when the frame cannot be specified to have been successfully delivered, the retransmission device cancels retransmission to the second communication apparatus and discards the frame to be retransmitted to the second communication apparatus.

29. A communication system according to claim 24, wherein the device for transmitting the delivery response information to the first communication apparatus, of the second communication apparatus, transmits the delivery response information as one of the medium access control frames of the medium access control super-frame payload.

30. A communication system according to claim 29, wherein, the device for transmitting the delivery response information to the communication apparatus further adds to a medium access control frame of the medium access control super-frame payload transmitted as the delivery response information, information indicating that the medium access control frame includes the delivery response information.