Wireless communication system

• US 20110286369A1
• Filed: 05/27/2011
• Published: 11/24/2011
• Est. Priority Date: 12/11/2000
• Status: Active Grant

• Current Assignee: Minoru Kosaka
• Original Assignee: Minoru Kosaka
• Inventors: KOSAKA, Minoru
• Granted Patent: US 8,270,390 B2
• Time in Patent Office: Days
• US Class Current: 370/280
• CPC Class Codes: H04B 7/265 for channel frequency control
• CPC Class Codes: H04J 3/06 Synchronising arrangements for television systems H04N5/04; bit-synchronisation H04L7/00
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04J 4/00 Combined time-division and frequency-division multiplex systems H04J13/00 takes precedence ; data transmission H04L5/26; telemetry G08C15/00
• CPC Class Codes: H04W 56/002 Mutual synchronization
• CPC Class Codes: H04W 56/0035 detecting errors in frequency or phase
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: H04W 72/12 Wireless traffic scheduling
• CPC Class Codes: H04W 72/21 in the uplink direction of a wireless link, i.e. towards the network
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/0816 with collision avoidance
• CPC Class Codes: H04W 76/14 Direct-mode setup
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 92/18 between terminal devices

Abstract

In a wireless communication system, a central control unit 31 comprises a synchronizing means for synchronizing a frame for an base station-mobile station communication with that for an inter-mobile station direct communication based on control information used for the base station-mobile station communication, when a second frequency is used for the inter-mobile station direct communication which is different from a first frequency used for the base station-mobile station communication. The central control unit 31 also comprises an allocation means for allocating a band and a frequency for the inter-mobile station direct communication in accordance with an allocation request from a base station 30 or a mobile station 40. Frames for the base station-mobile station communication and the inter-mobile station direct communication are synchronized by utilizing control information 55 for the base station-mobile station communication instead of the conventional control information provided by the mobile station. The system allows a base station-mobile station communication to take place even when an inter-mobile station direct communication is conducted at a frequency other than that of the base station. As the base station controls the inter-mobile station direct communication, the burden on the mobile stations can be reduced, and a single base station can use multiple frequencies simultaneously.

Claims

1. A wireless communication system comprised of:

a base station and one or more terminals, the wireless communication system carrying out wireless data communication by use of a first frequency band, wherein

a wireless access system employs not a frequency hopping system but a CSMA/CA and/or TDMA/TDD system as the wireless access system, and thus, the first frequency band is not periodically changed to another frequency band during data communication;

in addition to the first frequency band, a second frequency band different from the first frequency band is available for the wireless data communication;

the wireless data transmission at the first frequency band and the wireless data transmission at the second frequency band can be simultaneously carried out;

a transmission frame at the first frequency band is time-synchronized with the transmission frame at the second frequency band; and

the time synchronization is realized by a control signal transmitted from the base station at the first frequency band, and at the second frequency band, the control signal for the time synchronization is not transmitted.

2. The wireless communication system according to claim 1, wherein

the base station carries out carrier sensing at a plurality of frequency bands available as the second frequency band, and determines the second frequency band to be used;

and

by use of the control signal transmitted from the base station, information indicating allocation of the second frequency band is notified to the terminal.

3. The wireless communication system according to claim 1, wherein the terminal receives the control signal transmitted from the base station;

time-synchronizes transmission signals of the first frequency band and of the second frequency band; and

transmits the transmission signals.

4. A base station of a wireless communication system comprised of:

a base station and one or more terminals, the wireless communication system carrying out wireless data communication by use of a first frequency band, wherein

a wireless access system employs not a frequency hopping system but a CSMA/CA and/or TDMA/TDD system as the wireless access system, and thus, the first frequency band is not periodically changed to another frequency band during data communication;

in addition to the first frequency band, a second frequency band different from the first frequency band is available for the wireless data communication;

wireless data transmission at the first frequency band and the wireless data transmission at the second frequency band can be simultaneously carried out;

a transmission frame at the first frequency band is time-synchronized with the transmission frame at the second frequency band; and

the time synchronization is realized by a control signal transmitted from the base station at the first frequency band, and at the second frequency band, the control signal for the time synchronization is not transmitted.

5. The base station according to claim 4, wherein

the base station carries out carrier sensing at a plurality of frequency bands available as the second frequency band, and determines the second frequency band to be used;

and

by use of the control signal transmitted from the base station, information indicating allocation of the second frequency band is notified to the terminal.

6. A terminal station of a wireless communication system comprised of:

a base station and one or more terminals, the wireless communication system carrying out wireless data communication by use of a first frequency band, wherein

a wireless access system employs not a frequency hopping system but a CSMA/CA and/or TDMA/TDD system as the wireless access system, and thus, the first frequency band is not periodically changed to another frequency band during data communication;

in addition to the first frequency band, a second frequency band different from the first frequency band is available for the wireless data communication;

wireless data transmission at the first frequency band and the wireless data transmission at the second frequency band can be simultaneously carried out;

a transmission frame at the first frequency band is time-synchronized with the transmission frame at the second frequency band; and

the time synchronization is realized by a control signal transmitted from the base station at the first frequency band, and at the second frequency band, the control signal for the time synchronization is not transmitted.

7. The terminal station according to claim 6, wherein each terminal receives a control signal transmitted from the base station;

time-synchronizes transmission signals of the first frequency band and of the second frequency band; and

transmits the transmission signals.

8. A wireless communication system comprised of:

a base station, a first terminal, and a second terminal, the wireless communication system carrying out base station-terminal wireless data communication and inter-terminal direct wireless data communication by use of a first frequency band, wherein

the first terminal and the second terminal carry out the inter-terminal direct wireless data communication in a state of being connected to the base station;

a wireless access system employs not a frequency hopping system but a CSMA/CA and/or TDMA/TDD system as the wireless access system, and thus, the first frequency band is not periodically changed to another frequency band during data communication;

in addition to the first frequency band, a second frequency band different from the first frequency band is available for the wireless data communication;

wireless data transmission at the first frequency band and the wireless data transmission at the second frequency band can be simultaneously carried out;

a transmission frame at the first frequency band is time-synchronized with the transmission frame at the second frequency band; and

the time synchronization is realized by a control signal transmitted from the base station at the first frequency band, and at the second frequency band, the control signal for the time synchronization is not transmitted;

a request signal, for setting up inter-terminal direct wireless data communication between the first terminal and the second terminal, is transmitted from the second terminal to the base station;

a response signal of the request signal is transmitted from the base station to the first terminal; and

wherein the second frequency band, which is used for the inter-terminal direct wireless data communication between the first terminal and the second terminal, is notified to the first terminal and the second terminal by use of the control signal transmitted from the base station.

9. A base station of a wireless communication system comprised of:

a base station, a first terminal, and a second terminal, the wireless communication system carrying out base station-terminal wireless data communication and inter-terminal direct wireless data communication by use of a first frequency band, wherein

the first terminal and the second terminal carry out the inter-terminal direct wireless data communication in a state of being connected to the base station;

a wireless access system employs not a frequency hopping system but a CSMA/CA and/or TDMA/TDD system as the wireless access system, and thus, the first frequency band is not periodically changed to another frequency band during data communication;

in addition to the first frequency band, a second frequency band different from the first frequency band is available for the wireless data communication;

wireless data transmission at the first frequency band and the wireless data transmission at the second frequency band can be simultaneously carried out;

a transmission frame at the first frequency band is time-synchronized with the transmission frame at the second frequency band; and

the time synchronization is realized by a control signal transmitted from the base station at the first frequency band, and at the second frequency band, the control signal for the time synchronization is not transmitted;

a request signal, for setting up inter-terminal direct wireless data communication between the first terminal and the second terminal, which is transmitted from the second terminal to the base station;

a response signal of the request signal which is transmitted from the base station to the first terminal; and

the second frequency band, which is used for the inter-terminal direct wireless data communication between the first terminal and the second terminal, is notified to the first terminal and the second terminal by use of the control signal transmitted from the base station.

10. A terminal station of a wireless communication system comprised of:

a base station, a first terminal, and a second terminal, the wireless communication system carrying out base station-terminal wireless data communication and inter-terminal direct wireless data communication by use of a first frequency band, wherein

the first terminal and the second terminal carry out the inter-terminal direct wireless data communication in a state of being connected to the base station;

a wireless access system employs not a frequency hopping system but a CSMA/CA and/or TDMA/TDD system as the wireless access system, and thus, the first frequency band is not periodically changed to another frequency band during data communication;

in addition to the first frequency band, a second frequency band different from the first frequency band is available for the wireless data communication;

wireless data transmission at the first frequency band and the wireless data transmission at the second frequency band can be simultaneously carried out;

a transmission frame at the first frequency band is time-synchronized with the transmission frame at the second frequency band; and

the time synchronization is realized by a control signal transmitted from the base station at the first frequency band, and at the second frequency band, the control signal for the time synchronization is not transmitted;

a request signal, for setting up inter-terminal direct wireless data communication between the first terminal and the second terminal, is transmitted from the second terminal to the base station;

a response signal of the request signal which is transmitted from the base station to the first terminal; and

wherein the second frequency band, which is used for the inter-terminal direct wireless data communication between the first terminal and the second terminal, is notified to the first terminal and the second terminal by use of the control signal transmitted from the base station.