Station operation method and apparatus in TV whitespace
The present invention relates to a station (hereinafter, ‘STA’) operation method and apparatus in a TV whitespace. In a TVWS band, when an STA operating as an unlicensed device with permission to operate in an available channel not used by a licensed device needs to operate in the TVWS band by acquiring information on the available channel, the STA transmits an available channel information request message to a device having database information; receives, from the device having database information, an ACK message for the available channel information that includes (a) identification information on an available channel, (b) information on the maximum allowable power level in the available channel, and (c) information on valid time of the available channel; and transmits/receives a signal using the information of (a), (b) and (c), i.e., using the maximum allowable power level within the valid time in the available channel.
1. A method for a station to acquire information on an available channel for operation in a white space band, the method comprising:
transmitting an available channel information request message to a device having database information;
receiving an available channel information response message from the device having database information, the available channel information response message comprising:
(a) a field for a device type to which the available channel information response message can be applied;
(b) a field for identifying an available channel;
(c) a field for information on a maximum allowable power level on the available channel;
(d) a field for information on valid time of the available channel; and
(e) a length field,
wherein a triplet consisting of the (b), (c), and (d) fields is repeated by different numbers of times based on a value in the length field, if the field (a) corresponds to a fixed device or a device having an authority to directly access database information,
wherein the (b) and (c) fields are repeated by different numbers of times based on the value in the length field, if the field (a) corresponds to a device not having the authority to directly access database information; and
communicating a signal on the available channel using the information of one or more of (a), (b), (c), and (d).
2. The method according to claim 1 , wherein one or more of the available channel information request message and the available channel information response message comprise information on a plurality of available channels.
3. The method according to claim 1 , wherein:
the station comprises an access point (AP); and
the device having database information comprises a database.
4. The method according to claim 3 , wherein the available channel information request message and the available channel information response message comprise a channel scheduling request message and a channel scheduling response message, respectively.
5. The station operation method according to claim 1 , wherein the available channel information request message comprises:
a category field that indicates a category of the available channel information request message;
an action value field that indicates an action to be performed through the available channel information request message in the category;
a source address field that indicates an address of a device transmitting the available channel information request message;
a destination address field that indicates an address of a device receiving the available channel information request message; and
a field that indicates identification information on a plurality of available channels.
6. The method according to claim 1 , wherein the available channel information response message further comprises:
a category field that indicates a category of the available channel information response message;
an action value field that indicates an action to be performed through the available channel information response message in the category;
a source address field that indicates an address of a device transmitting the available channel information response message; and
a destination address field that indicates an address of a device receiving the available channel information response message.
7. The method according to claim 1 , wherein the information on valid time comprises information on an available duration of the available channel, starting from a reception time receiving the available channel information response message.
8. The method according to claim 1 , wherein the information on valid time comprises:
information on available start time of the available channel according to the available channel information response message; and
information on an available duration of the available channel, starting from the available start time.
9. The method according to claim 1 , wherein:
the device having database information comprises an AP (Access Point); and
the station is served by the AP.
10. A station acquiring information on an available channel for operating in a white space band, the station comprising:
a transceiver configured to:
transmit an available channel information request message to a device having database information; and
receive, from the device having database information, an available channel information response message comprising:
(a) a field for a device type to which the available channel information response message can be applied;
(b) a field for identifying an available channel;
(c) a field for information on a maximum allowable power level on the available channel;
(d) a field for information on valid time of the available channel; and
(e) a length field,
wherein a triplet consisting of the (b), (c), and (d) fields is repeated by different numbers of times based on a value in the length field, if the field (a) corresponds to a fixed device or a device having an authority to directly access database information,
wherein the (b) and (c) fields are repeated by different numbers of times based on the value in the length field, if the field (a) corresponds to a device not having the authority to directly access database information; and
a processor configured to control the transceiver to communicate a signal on the available channel using the information of one or more of (a), (b), (c), and (d).
11. The station according to claim 10 , wherein one or more of the available channel information request message and the available channel information response message comprise information on a plurality of available channels.
12. The station according to claim 10 , wherein:
the station comprises an access point (AP); and
the device having database information comprises a database.
13. The station according to claim 12 , wherein the available channel information request message and the available channel information response message comprise a channel scheduling request message and a channel scheduling response message, respectively.
14. The station according to claim 10 , wherein the information on valid time comprises information on an available duration of the available channel, starting from a reception time receiving the available channel information response message.
15. The station according to claim 10 , wherein the information on valid time comprises:
information on available start time of the available channel according to the available channel information response message; and
information on an available duration of the available channel, starting from the available start time.
16. The station according to claim 10 , wherein:
the device having database information comprises an AP; and
the station is served by the AP.