Terminal station radio communication device, based station radio communication device, radio communication device, radio communication method, and radio communication program

• US 8,045,529 B2
• Filed: 10/19/2006
• Issued: 10/25/2011
• Est. Priority Date: 02/08/2006
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Horiguchi, Tomoya, Tomizawa, Takeshi, Tandai, Tomoya, Deguchi, Noritaka, Tomioka, Tazuko
• Primary Examiner(s): Corsaro; Nick
• Assistant Examiner(s): PATEL, MAHENDRA R
• Application Number:
  US11/583,134
• Publication Number:
  US 20070183392A1
• Time in Patent Office: 1,832 Days
• Field of Search: 455/436, 455/502, 455/556, 370/335, 370/346, 370/428, 370/348, 370/229, 380/247
• US Class Current: 370/335
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 52/245 taking into account received signal strength
• CPC Class Codes: H04W 74/0808 using carrier sensing, e.g. carrier sense multiple access [CSMA]

Abstract

A terminal station radio communication device belongs to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel. The terminal station radio communication device includes: a transmission power determining unit which sets up signal transmission power, the signal transmission power being usable for communications between radio communication devices belonging to the second radio communication system, and being determined such that reception power at the radio base station is below a predetermined threshold; a synchronizer enabling the radio terminal station to obtain timing information to start signal transmission; and a signal transmitter starting transmitting the signal at the timing represented by the timing information and terminating the signal transmission within a predetermined time period.

Claims

1. A terminal station radio communication device belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined transmission time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the terminal station radio communication device comprising:

a frequency selector for changing frequency channels;

a transmission power determining unit which sets up signal transmission power, the signal transmission power being used for communications between radio communication devices belonging to the second radio communication system, and being determined such that reception power at the radio base station is below a predetermined threshold;

a synchronizer enabling the terminal station radio communication device belonging to the second radio communication system to acquire timing information to start signal transmission;

a signal transmitter starting transmitting the signal at the timing represented in the timing information and terminating the signal transmission within a predetermined time period; and

a carrier sensor which detects a carrier signal in a short time period from the timing represented in the timing information obtained from the synchronizer until a lapse of the predetermined time period, and enabling the signal transmitter to send the signal when reception power is found to be below the predetermined threshold during the carrier signal detection.

2. The terminal station radio communication device defined in claim 1, wherein the frequency selector changes a current frequency channel to another frequency channel when the number of times in which the reception power detected by the carrier sensor is above the predetermined threshold is above a predetermined threshold.

9. The terminal station radio communication device defined in claim 1, wherein the radio terminal station belonging to the first radio communication system acquires data concerning a time period for sending a string of signal from the announcement information of the first radio communication system which includes transmission power of an announcement information signal.

3. A base station radio communication device belonging to a second radio communication system which shares a frequency channel and communicates with a first radio communication system in which a radio terminal station communicates with a radio base station using a predetermined frequency channel within a predetermined transmission time period, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the base station radio communication device comprising:

a frequency selector for changing frequency channels;

an announcement information receiver receiving announcement information including transmission power of an announcement information signal from the radio base station;

a reception power meter measuring reception power of the announcement information;

a reception sensitivity information memory which stores information concerning reception sensitivity of the radio base station for receiving a signal from the terminal station radio communication device;

a signal transmitter; and

a transmission power determining unit which determines transmission power based on the transmission power and reception power of the announcement information, and enables the signal transmitter to send announcement information concerning the transmission power, using the determined transmission power.

4. The base station radio communication device defined in claim 3, wherein when candidate transmission power which is derived on the basis of a transmission loss calculated using the transmission power and the reception sensitivity information is equal to or larger than a target transmission power, the signal transmitter sends announcement information listing the candidate transmission power as the transmission power;

and when the candidate transmission power is equal to or smaller than the target transmission power, the frequency selector enables the signal transmitter to perform signal transmission using a frequency channel different from a current frequency channel.

5. A terminal station radio communication device belonging to a second radio communication system which shares the same frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station using a predetermined frequency channel within a predetermined transmission time period, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the terminal station radio communication device comprising:

a frequency selector for changing frequency channels;

an announcement information receiver receiving announcement information including transmission power of an announcement information signal from the radio base station;

a reception power meter measuring power for receiving the announcement information; and

a reception sensitivity memory storing information concerning reception sensitivity of the radio base station for receiving a signal from the terminal station radio communication device,

wherein one or more exchanges of a data frame and a response frame performed between radio communication devices belonging to the second radio communication system are completed within a time period during which a radio terminal station belonging to the first radio communication system continuously sends signals once.

6. A radio communication device belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station using a predetermined frequency channel within a predetermined transmission time period, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication device comprising:

a frequency selector for changing frequency channels;

a first signal transmitter-receiver unit transmitting and receiving signals for the first radio communication system;

a transmission power determining unit determining transmission power in order that signal power is equal to or smaller than a carrier sense level during an inter-frame space of the first radio communication system at the radio terminal station and the radio base station belonging to the first radio communication system;

an inter-frame space determining unit determining an inter-frame space on the basis of an output of the first signal transmitter-receiver unit; and

a second signal transmitter-receiver unit sending a signal of the second communication system during the inter-frame space of the first radio communication system.

8. The radio communication device defined in claim 6, wherein radio communication devices belonging to the second radio communication system perform radio communications for the second radio communication system as well as radio communications for the first radio communication system.

7. A radio communication device belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station using a predetermined frequency channel within a predetermined transmission time period, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication device comprising:

a frequency selector for changing frequency channels;

a first signal transmitter-receiver unit transmitting and receiving signals for the first radio communication system;

a memory storing information concerning allowable interference levels of the radio terminal station and radio base station belonging to the first radio communication system;

a control unit determining a signal transmission period on the basis of header information included in a packet received from the radio terminal station and radio base station belonging to the first radio communication system;

a transmission power determining unit determining transmission power in order that signal power at the radio terminal station and radio base station is equal to or smaller than an allowable interference level of the first radio communication system at the radio terminal station and radio base station; and

a second signal transmitter-receiver unit sending a signal of the second radio communication system in a transmission time period determined by the control unit and using transmission power determined by the transmission power determining unit.

10. A radio communication method carried out by a radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication method comprising:

setting up signal transmission power which is used for communications between radio communication devices belonging to the second radio communication system, the transmission power being determined such that reception power at the radio base station is below a predetermined threshold;

acquiring timing information for the radio terminal station belonging to the first radio communication system to start signal transmission;

starting the signal transmission at the timing included in the timing information and using the signal transmission power, and completing the signal transmission within a predetermined time period; and

detecting a carrier signal in a short time period from the timing represented in the acquired timing information until a lapse of the predetermined time period, and enabling the signal transmission when reception power is found to be below the predetermined threshold during the carrier signal detection.

11. A radio communication method carried out by a radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication method comprising:

letting the radio communication device transmit and receive announcement information including transmission power of an announcement information signal from the radio base station;

measuring reception power of the announcement information;

storing information concerning reception sensitivity of the radio base station for receiving a signal from the base station radio communication device; and

determining transmission power based on the transmission power and reception power of the announcement information and enabling a signal transmitter to send announcement information concerning the transmission power, using the determined transmission power.

12. A radio communication method carried out by a terminal station radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication method comprising:

letting the radio communication device transmit and receive signals for the first radio communication system;

determining transmission power such that signal power at the radio terminal stations and radio base stations belonging to the first radio communication system is equal to or less than a carrier sense level in an inter-frame space of the first radio communication system;

determining the inter-frame space of the first radio communication system on the basis of the signal power; and

sending a signal for the second radio communication system in the inter-frame space.

13. A radio communication method carried out by a terminal station radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication method comprising:

letting the radio communication device transmit and receive signals for the first radio communication system;

storing allowable interference levels of the radio terminal station and radio base station belonging to the first radio communication system;

determining a signal transmission period on the basis of header information listed in a packet which is transmitted by the radio terminal station and radio base station;

determining transmission power in order that signal power at the radio terminal station and radio base station belonging to the first radio communication system is equal to less than an allowable interference level of the first radio communication system; and

transmitting a signal for the second radio communication system in the signal transmission period and using the transmission power.

14. A radio communication method carried out by a terminal station radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication method comprising:

letting the radio communication device set up signal transmission-reception power in order that reception power which enables communications between radio communication devices of the second radio communication system and is at the radio base station is equal to or less than a predetermined threshold;

acquiring information concerning timing to transmit a signal from the radio terminal station belonging to the first radio communication system;

starting transmitting the signal at the timing in the timing information and using the signal transmission power, and terminating transmitting the signal within a predetermined time period; and

detecting a carrier signal in a short time period from the timing represented in the acquired timing information until a lapse of the predetermined time period, and enabling the signal transmission when reception power is found to be below the predetermined threshold during the carrier signal detection.

15. A radio communication program, tangibly embodied in a non-transitory computer-readable storage medium, used by a terminal station radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication program comprising:

letting the radio communication device receive announcement information including transmission power of an announcement information signal from the radio base station;

measuring reception power of the announcement information;

storing information concerning reception sensitivity of the radio base station for receiving a signal from the base station radio communication device; and

determining transmission power based on the transmission power and reception power of the announcement information, and enabling a signal transmitter to send announcement information concerning the transmission power, using the determined transmission power.

16. A radio communication program, tangibly embodied in a non-transitory computer-readable storage medium, used by a terminal station radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication program comprising:

letting the radio communication device transmit and receive signals for the first radio communication system;

determining transmission power such that signal power at the radio terminal station and radio base station belonging to the first radio communication system is equal to or less than a carrier sense level in an inter-frame space of the first radio communication system;

determining the inter-frame space of the first radio communication system on the basis of the signal power; and

sending a signal for the second radio communication system in the inter-frame space.

17. A radio communication program, tangibly embodied in a non-transitory computer-readable storage medium, used by a terminal station radio communication device including a frequency selector for changing frequency channels and belonging to a second radio communication system which shares a frequency channel with a first radio communication system in which a radio terminal station communicates with a radio base station in a predetermined time period using a predetermined frequency channel, the second radio communication system being allowed to use the frequency channel with lower priority over the first radio communication system, the radio communication program comprising:

letting the radio communication device transmit and receive signals for the first radio communication system;

storing allowable interference levels of the radio terminal station and radio base station belonging to the first radio communication system;

determining a signal transmission period on the basis of header information listed in a packet which is transmitted by the radio terminal station and radio base station;

determining transmission power in order that signal power at the radio terminal station and radio base station belonging to the first radio communication system is equal to less than an allowable interference level of the first radio communication system; and

transmitting a signal for the second radio communication system in the signal transmission period and using the transmission power.