COMMUNICATION METHOD USING DIRECT LINK IN WIRELESS NETWORK AND APPARATUS THEREFOR

• US 20080075038A1
• Filed: 07/23/2007
• Published: 03/27/2008
• Est. Priority Date: 09/26/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: JIN, Ho, CHO, Kyung-ik
• Granted Patent: US 9,521,556 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04B 17/26 using historical data, averaging values or statistics
• CPC Class Codes: H04B 17/309 Measuring or estimating channel quality parameters
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 36/20 for optimising the interference level

Abstract

A communication method using a direct link in a wireless network and an apparatus therefor are provided. Accordingly, it is determined whether the quality of a link channel is lower than a level during communication using the direct link or whether a signal which is received through the channel includes a radar signal, and the direct link channel is selectively changed to a new channel based on the determination result.

Claims

1. A communication method in a wireless network using a direct link, the method comprising:

determining whether a quality of a direct link channel is lower than a level or whether a signal received through the direct link channel includes a radar signal, during communication using the direct link; and

selectively changing the direct link channel to a first channel based on a result from the determining of the quality of the direct link channel.

2. The method of claim 1, wherein the selectively changing the direct link channel to the first channel comprises:

changing by a station from a current channel to a primary channel and requesting by the station the access point to allocate an available channel; and

changing the direct link channel to a channel that is allocated in response to the request for the available channel.

3. The method of claim 1, wherein the determining whether quality of the direct link channel is lower than the level is determining whether cases where an averaged received signal strength indication (RSSI) is less than a threshold successively occur more frequently than a frequency.

4. The method of claim 1, wherein the determining whether the quality of the direct link channel is lower than the level is determining whether a number of successive retrials reaches a retry limit of a number of times in the time it takes to transmit a number of frames.

5. The method of claim 1, wherein the determining whether the received signal includes the radar signal comprises:

measuring to determine whether received signal strength indication (RSSI) exceeds a threshold;

determining whether the received signal includes a signal that is estimated to be the radar signal if the RSSI exceeds the threshold from a result of the measuring to determine whether RSSI exceeds the threshold; and

determining whether the signal that is estimated to be the radar signal is a radar signal if the received signal includes the signal that is estimated to be the radar signal.

6. The method of claim 5, wherein the determining whether the received signal includes the signal that is estimated to be the radar signal further comprises reducing the strength of a wireless local area network (LAN) signal so that a strength difference between the wireless LAN signal and the signal that is estimated to be the radar signal is equal to or less than a strength difference threshold, if the received signal includes the wireless LAN signal, and the strength difference is equal to or greater than the strength difference threshold.

7. The method of claim 5, wherein the determining whether the received signal includes the signal that is estimated to be the radar signal comprises determining that the received signal includes the signal that is estimated to be the radar signal, if a wireless local area network (LAN) packet is detected in the received signal, and a signal error caused by inaccurately receiving signal information occurs.

8. The method of claim 5, wherein the determining whether the received signal includes the signal that is estimated to be the radar signal comprises determining that the received signal includes the signal that is estimated to be the radar signal, if a wireless local area network (LAN) packet is detected in the received signal, and an equalized signal to noise ratio sharply decreases.

9. The method of claim 5, wherein the determining whether the received signal includes the signal that is estimated to be the radar signal comprises determining that the received signal includes the signal that is estimated to be the radar signal, if a wireless local area network (LAN) packet is detected in the received signal, and a frame check sequence (FCS) error caused by inaccurately receiving contents of data occurs.

10. The method of claim 5, wherein the determining whether the received signal includes the signal that is estimated to be the radar signal comprises:

determining whether power decreases by detecting a pulse in the received signal, if no wireless local area network (LAN) packet is detected in the received signal; and

determining that the received signal includes the signal that is estimated to be the radar signal, based on whether the pulse is periodic and whether it is determined that the power of the pulse decreases.

11. The method of claim 5, wherein the determining whether the received signal includes the signal that is estimated to be the radar signal comprises:

measuring a parameter of the received signal;

storing the parameter; and

determining whether the signal that is estimated to be the radar signal is the radar signal by analyzing the stored parameter.

12. The method of claim 11, wherein the measuring the parameter and the storing the measured parameter are repeatedly performed until a number of the stored parameters exceeds a parameter number threshold.

13. The method of claim 11, wherein the parameter includes at least one of a generation time of the received signal, pulse width, and an interval between a current signal and a previous signal.

14. The method of claim 11, wherein in the determining whether the signal that is estimated to be the radar signal, the signal that is estimated to be the radar signal is determined as the radar signal if the period of the signal that is estimated to be the radar signal is similar to that of the radar signal.

30. A computer-readable recording medium having embodied thereon a computer program for executing the method of claim 1.

15. A station in a wireless network using a direct link, the station comprising:

a channel analyzer which determines whether a quality of a direct link channel is lower than a level or whether a signal received through the direct link channel includes a radar signal, during communication using a direct link;

a frame generator which generates a frame used for selectively changing the direct link channel to another channel based on a result of the determining of the quality of the direct link channel by the channel analyzer; and

a frame transceiver which transmits the generated frame to an access point or a first station and receives the generated frame from the access point or the first station.

16. The station of claim 15, wherein the channel analyzer comprises:

a channel state determiner which determines whether quality of the direct link channel is lower than the level, during communication using the direct link; and

a radar signal detector which determines whether the signal received through the channel includes the radar signal.

17. The station of claim 16, wherein the channel state determiner determines that the quality of the channel is bad if cases where an averaged received signal strength indication (RSSI) is less than a threshold, successively occur more frequently than a frequency.

18. The station of claim 16, wherein the channel state determiner determines that the quality of the channel is bad if a number of successive retrials reaches a retry limit more than a number of times in the time it takes to transmit a number of frames.

19. The station of claim 16, wherein the radar signal detector comprises:

a signal strength measurer which measures to determine whether a strength of the received signal exceeds a threshold;

an estimated radar signal detector which detects whether the received signal includes the signal that is estimated to be the radar signal, if as a result of measuring signal strength it is determined that the strength of the received signal exceeds the threshold; and

a radar signal determiner which determines whether the signal that is estimated to be the radar signal is the radar signal, if the received signal includes the signal that is estimated to be the radar signal as a result of detection of the estimated radar signal detector.

20. The station of claim 19, wherein the estimated radar signal detector reduces strength of the wireless (local area network) LAN signal so that a strength difference between the wireless LAN signal and the signal that is estimated to be the radar signal is equal to or less than a strength difference threshold, if the received signal includes the wireless LAN signal, and the strength difference is equal to or greater than the strength difference threshold.

21. The station of claim 19, wherein the estimated radar signal detector determines that the received signal includes the signal that is estimated to be the radar signal if a wireless (local area network) LAN packet is detected in the received signal, and a signal error caused by inaccurately receiving signal information occurs.

22. The station of claim 19, wherein the estimated radar signal detector determines that the received signal includes the signal that is estimated to be the radar signal if a wireless (local area network) LAN packet is detected in the received signal, and an equalized signal to noise ratio sharply decreases.

23. The station of claim 19, wherein the estimated radar signal detector determines that the received signal includes the signal that is estimated to be the radar signal, if a wireless (local area network) LAN packet is detected in the received signal, and an FCS (frame check sequence) error caused by inaccurately receiving contents of data occurs.

24. The station of claim 19, wherein if no wireless (local area network) LAN packet is detected in the received signal, the estimated radar signal detector determines whether power decreases by detecting a pulse in the signal, and if it is determined that the power of the pulse decreases, the estimated radar signal detector analyzes whether the pulse is periodic and determines that the received signal includes the signal that is estimated to be the radar signal if the pulse is periodic.

25. The station of claim 19, wherein the radar signal determiner comprises:

a parameter measurer which measures a parameter from the received signal, if the received signal includes the signal that is estimated to be the radar signal, as a result of the detection of the estimated radar signal detector;

a buffer which stores the parameter measured by the parameter measurer; and

a parameter analyzer which determines whether the signal that is estimated to be the radar signal is the radar signal by analyzing the parameters stored in the buffer.

26. The station of claim 25,

wherein the parameter measurer repeatedly measures the parameter until a number of the parameters stored in the buffer exceeds a parameter number threshold, and

wherein the buffer repeatedly stores the parameter measured by the parameter measurer until a number of the stored parameters exceeds the parameter number threshold.

27. The station of claim 25, wherein the parameter includes at least one of a generation time of the received signal, pulse width, and an interval between a current signal and a previous signal.

28. The station of claim 25, wherein the parameter analyzer determines that the signal that is estimated to be the radar signal is the radar signal, if a period of the signal that is estimated to be the radar signal is similar to that of the radar signal.

29. An access point in a wireless network using a direct link, the access point comprising:

a channel manager which periodically scans available channels for allocating channels, analyzes the scanned channels, and generates a list of the available channels;

a channel number recorder which records a channel number in a channel list that is recorded in a channel change request frame, when receiving the channel change request frame from a station; and

a frame transceiver which retransmits a channel change response frame, which is a response to the channel change request frame, to another station.