WIRELESS COMMUNICATION SYSTEM AND WIRELESS COMMUNICATION METHOD

• US 20150172012A1
• Filed: 07/19/2013
• Published: 06/18/2015
• Est. Priority Date: 07/19/2012
• Status: Active Grant

• Current Assignee: Nippon Telegraph and Telephone Corporation
• Original Assignee: Nippon Telegraph and Telephone Corporation
• Inventors: Abeysekera, Hirantha Sithira, Inoue, Yasuhiko, Asai, Yusuke, Ichikawa, Takeo, Mizoguchi, Masato, Shinohara, Shoko
• Granted Patent: US 9,998,262 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04J 1/00 Frequency-division multiplex systems H04J14/00 takes precedence
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04J 11/005 of intercell interference
• CPC Class Codes: H04J 11/0053 using co-ordinated multipoint transmission/reception co-ordinated antenna or beam-forming aspects H04B7/022
• CPC Class Codes: H04J 11/0063 of multipath interference, e.g. Rake receivers
• CPC Class Codes: H04L 1/18 Automatic repetition systems, e.g. Van Duuren systems
• CPC Class Codes: H04L 1/1854 Scheduling and prioritising arrangements
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0023 Time-frequency-space
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0035 Resource allocation in a cooperative multipoint environment
• CPC Class Codes: H04L 5/0087 when data requirements change
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 28/16 Central resource management; Negotiation of resources or communication parameters, e.g. negotiating bandwidth or QoS [Quality of Service]
• CPC Class Codes: H04W 72/27 between access points
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

In order to provide a wireless communication system capable of improving the throughput of wireless communication by effectively using frequency resources, in a wireless communication system in which a first wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other, the first wireless access point includes a transmission opportunity acquiring unit which acquires a transmission opportunity when data to be transmitted is generated; and a transmitting unit of permission for use which transmits permission for use of channels which are not scheduled to use within the first cell, to the second wireless access point in a period in which the transmission opportunity is acquired, and the second wireless access point includes a communication unit which communicates with the wireless station within the second cell via the channel in which the permission for use is acquired from the first wireless access point.

Claims

1. A wireless communication system in which a first wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other,

wherein the first wireless access point comprises:

a transmission opportunity acquiring unit which acquires a transmission opportunity when data to be transmitted is generated; and

a transmitting unit of permission for use which transmits permission for use of channels which are not scheduled to use within the first cell, to the second wireless access point in a period in which the transmission opportunity is acquired, and

the second wireless access point comprises a communication unit which communicates with the wireless stations within the second cell via the channels in which the permission for use is acquired from the first wireless access point.

2. The wireless communication system according to claim 1, wherein the transmitting unit of the permission for use transmits the permission for use of a secondary channel that is not scheduled to be used via a primary channel.

3. The wireless communication system according to claim 1, wherein the transmitting unit of the permission for use transmits the permission for use of a secondary channel that is not scheduled to be used via all channels.

4. The wireless communication system according to claim 1, wherein the transmitting unit of the permission for use transmits the permission for use of a channel on which a transmission permission is not sent as a reply to a transmission request transmitted via all channels.

5. The wireless communication system according to claim 1, wherein the transmitting unit of the permission for use transmits the permission for use of a channel that is not scheduled to be used based on a reply of transmission permission to a transmission request transmitted via all channels.

6. The wireless communication system according to claim 1, wherein the transmitting unit of the permission for use transmits the permission for use of a secondary channel when a wireless station with which to be communicated is not available of the orthogonal frequency division multiple access.

7. The wireless communication system according to claim 1, wherein the transmitting unit of the permission for use transmits the permission for use of a secondary channel when a wireless station with which to be communicated is not available of the orthogonal frequency-division multiple access, and

the wireless stations associated with the second wireless access point acquiring the permission for use reply a transmission permission in accordance with an available channel.

8. The wireless communication system according to claim 1, wherein the first wireless access point performs data transmission after determining a channel of which the permission for use is assignable and transmitting the permission for use via a primary channel through the transmitting unit of the permission for use.

9. The wireless communication system according to claim 1, wherein the first wireless access point performs data transmission after determining a channel of which the permission for use is assignable and transmitting the permission for use via all channels through the transmitting unit of the permission for use.

10. The wireless communication system according to claim 1, wherein the first wireless access point performs data transmission after determining a channel of which the permission for use is assignable, transmitting the permission for use via a primary channel through the transmitting unit of the permission for use, and receiving a positive acknowledgement for the permission for use.

11. The wireless communication system according to claim 1, wherein the first wireless access point performs data transmission after determining a channel of which the permission for use is assignable, transmitting the permission for use via all channels through the transmitting unit of the permission for use, and receiving a positive acknowledgement for the permission for use.

12. A wireless communication system in which a first wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other,

wherein each wireless station within the first cell comprises:

a first data receiving unit which receives different data destined to different wireless stations transmitted from the first wireless access point on different channels by the orthogonal frequency-division multiple access; and

a first acknowledgement transmitting unit which transmits a first acknowledgement if the data is correctly received by the first data receiving unit, and

each wireless station within the second cell comprises;

a second data receiving unit which receives data transmitted from the second wireless access point by the orthogonal frequency-division multiple access on a channel for which permission for use is acquired from the first wireless access point; and

a second acknowledgement transmitting unit which transmits a second acknowledgement if the data is correctly received by the second data receiving unit.

13. The wireless communication system according to claim 12, wherein replies of the first acknowledgement and the second acknowledgement with which the first acknowledgement transmitting unit and the second acknowledgement transmitting unit reply, respectively, are made using uplink orthogonal frequency-division multiple access.

14. The wireless communication system according to claim 12, wherein the second wireless access point comprises a transmission opportunity acquiring unit which acquires a transmission opportunity, and

wherein an acknowledgement is transmitted after the transmission opportunity is acquired.

15. The wireless communication system according to claim 12, wherein the second acknowledgement transmitting unit transmits the second acknowledgement on a primary channel after the first acknowledgement transmitting unit transmits the first acknowledgement on the primary channel.

16. A wireless communication method to be performed by a wireless communication system in which a first wireless access point which communicates with one more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other, the method comprising:

a transmission opportunity acquiring step of acquiring, by the first wireless access point, a transmission opportunity when data to be transmitted is generated; and

a use permission transmitting step of transmitting, at the first wireless access point, permission for use of channels which are not scheduled to use within the first cell, to the second wireless access point in a period in which the transmission opportunity is acquired.

17. The wireless communication method according to claim 16, further comprising a communication step of communicating, by the second wireless access point, with the wireless stations within the second cell via the channels in which the permission for use is acquired from the first wireless access point.

18. A wireless communication method to be performed by a wireless communication system in which a first wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and a second wireless access point which is capable of performing carrier sensing with the first wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other, the method comprising:

a first data receiving step of receiving different data, at the wireless stations within the first cell, destined to different wireless stations transmitted from the first wireless access point on different channels by the orthogonal frequency-division multiple access;

a first acknowledgement transmitting step of transmitting, by the wireless stations within the first cell, an acknowledgement if the data is correctly received in the first data receiving step;

a second data receiving step of receiving, by the wireless stations within the second cell, data transmitted from the second wireless access point by the orthogonal frequency-division multiple access on a channel for which permission for use is acquired from the first wireless access point; and

a second acknowledgement transmitting step of transmitting, by the wireless stations within the second cell, an acknowledgement if the data is correctly received in the second data receiving step.

19. A wireless access point in a wireless communication system in which a wireless access point which communicates with one or more wireless stations within a first cell by orthogonal frequency-division multiple access and another wireless access point which is capable of performing carrier sensing with the wireless access point and communicates with one or more wireless stations within a second cell by the orthogonal frequency-division multiple access operate in cooperation with each other,

wherein wireless access point comprises:

a transmission opportunity acquiring unit which acquires a transmission opportunity when data to be transmitted is generated; and

a transmitting unit of permission for use which transmits permission for use of channels which are not scheduled to use within the first cell, to the other wireless access point in a period in which the transmission opportunity is acquired.