Sensor gateway

• US 9,998,501 B2
• Filed: 12/02/2014
• Issued: 06/12/2018
• Est. Priority Date: 12/02/2014
• Status: Active Grant

• Current Assignee: NETGEAR, Inc.
• Original Assignee: NETGEAR, Inc.
• Inventors: Emmanuel, Joseph Amalan Arul, Amini, Peiman
• Primary Examiner(s): Crompton, Christopher R
• Application Number:
  US14/558,085
• Publication Number:
  US 20160156673A1
• Time in Patent Office: 1,288 Days
• Field of Search: 370338
• CPC Class Codes: H04L 65/102 Gateways arrangements for connecting between networks having differing types of switching systems, e.g. gateways, H04L12/66
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 4/38 for collecting sensor information
• CPC Class Codes: H04W 88/16 Gateway arrangements
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

A sensor gateway manages wireless communications to sensors and the exchange of data between the sensors and a connection to the Internet. A sensor gateway processor runs the network and wireless stack, automatically picks the same channel as the home access point (AP), and runs sensor software to provide the sensors with low power, wireless support and deep sleep support. The sensor gateway selects same channel as the home AP by following the strongest beacon or by following the home AP service set identifier (SSID), in case more than one strong beacon is present. If the home AP and sensor gateway are placed close by and are on a different channel in 2.4G, there is destructive interference between the two devices. By using same channel on the sensor gateway as that of the home AP, both devices can coexist in same band without destructive interference.

Claims

1. A method for managing wireless communications between a plurality of sensors and a backend connection, comprising:

providing a sensor gateway in wireless communication with said sensors within a communications band over a first channel of a plurality of channels, said sensor gateway exchanging information between said sensors and said backend connection via a home access point (AP) or gateway, said AP or gateway engaging in wireless communications within said communications band over a selected channel of the plurality of channels; and

said sensor gateway automatically determining a characteristic of a beacon frame and switching from the first channel to said selected channel when the characteristic of the beacon frame indicates that communication via said selected channel will be improved relative to communications via the first channel, causing said sensor gateway to communicate via a same channel as said AP or gateway and facilitating reduced communication interference between said sensor gateway and said AP or gateway, said same channel being said selected channel.

2. The method of claim 1, further comprising:

said sensor gateway executing software to provide said sensors with low power, wireless support and deep sleep support.

3. The method of claim 1, wherein said sensor gateway operates in a 2.4 GHz band.

4. The method of claim 1, wherein said sensor gateway automatically switching from the first channel to said selected channel is based on the characteristic of the beacon frame indicating a strongest beacon.

5. The method of claim 4, wherein said sensor gateway selecting the same channel as the AP or gateway based on the characteristic of the beacon frame indicating the strongest beacon is further based on the AP or gateway service set identifier (SSID) when more than one strong beacon is present.

6. The method of claim 1, further comprising:

said sensor gateway and AP or gateway listening to each other; and

either of the sensor gateway and AP or gateway transmitting a back-off signal to share the channel.

7. The method of claim 1, further comprising:

said sensor gateway executing software to receive sensory information from said sensors, process said information, and send selected processed information to said backend connection.

8. The method of claim 1, further comprising:

said sensor gateway executing software to accommodate said sensors'"'"' less frequent wake-up schedule;

wherein the sensors use less energy.

9. The method of claim 1, further comprising:

said sensor gateway executing software to buffer sensor data.

10. The method of claim 1, further comprising:

said sensor gateway transmitting a beacon to said sensors at a higher data rate to reduce the sensor wake up time.

11. The method of claim 1, further comprising:

said sensor gateway reordering beacon content, wherein important data is sent first to allow the sensor to go to sleep sooner.

12. The method of claim 1, further comprising:

said sensor gateway waiting for a sensor to send a keep-alive or other form of message, rather than polling the sensor, to indicate that the sensor is active.

13. The method of claim 1, wherein said sensor gateway switching from the first channel to said selected channel is based on, when the AP or gateway and sensor gateway are proximate to each other, a relative beacon strength;

and

a user picking a basic service set identifier (BSSID) for a device which has more traffic in the traffic monitoring system as the home AP or gateway when there are two or more sets of strong beacons with substantially the same power.

14. The method of claim 1, further comprising:

said sensor gateway selecting a channel with reduced communication interference when there is no AP or gateway in close range, as indicated by a beacon power that is less than a threshold.

15. The method of claim 1, further comprising:

said sensor gateway using a LAN connection with the AP or gateway to learn a MAC address of the AP or gateway, wherein the MAC address uniquely identifies a Wi-Fi beacon that belongs to the AP or gateway.

16. The method of claim 1, further comprising:

using a carrier sense multiple access with collision avoidance (CSMA/CA) system to arbitrate between the AP or gateway and the sensor gateway.

17. The method of claim 1, further comprising:

manually selecting a channel of the AP or gateway as that with which said sensor gateway is to coordinate its operation when more than one AP and/or gateway with a strong received signal is present.

18. The method of claim 1, further comprising:

said sensor gateway periodically scanning a current channel;

the sensor gateway scanning other channels to select a channel with a strongest average signal when said sensor gateway no longer sees the AP or gateway on the current channel and then switching to that channel.

19. The method of claim 1, further comprising:

said sensor gateway sending a channel switch announcement to let sensors with which said sensor gateway is configured know that said sensor gateway is going to switch to another channel to enable the sensors to follow the sensor gateway when the sensor gateway switches to the other channel.

20. The method of claim 1, further comprising:

said sensor gateway employing a channel selection scheme in which any of the following steps are performed;

when a scan by the sensor gateway detects one or more APs or gateways operating within close proximity to the sensor gateway, as estimated by a received signal strength indication (RSSI) from each AP, then the sensor gateway switching from said selected channel to another channel based on the AP with highest RSSI, wherein the sensor gateway also returns data that indicates an SSID and BSSID, utilized in association with the other channel, to the application layer of all APs within three meters;

when the sensor gateway has selected a channel of a nearby AP or gateway, It monitors that AP'"'"'s or gateway'"'"'s traffic for channel change announcements, and follows a channel change of that AP if the channel has changed;

on command from a host application, forcing the sensor gateway to rescan channels for a best available network;

if at any time the sensor gateway changes its channel, it broadcasts a channel change announcement to all stations within a BSS;

enabling auto-channel selection by default, wherein the host application can disable auto-channel selection;

if at any time the sensor gateway determines that there is no longer an AP in close proximity, then it no longer follows channel changes of any AP;

when the sensor gateway changes a communication channel of an AP with which it is in communication, it announces the change to an application layer;

when the sensor gateway is following channel changes of an AP and then no longer follows channel changes of any AP, it announces the change to the application layer;

when the sensor gateway is manually set to follow channel changes of an AP, it always follows channel changes of that AP, even if there are closer APs or if that AP RSSI has dropped significantly low;

providing a programmable RSSI threshold to detect an AP within a predetermined distance to allow adjustment of the programmable RSSI threshold if needed;

the sensor gateway scanning available Wi-Fi channels for a best channel to use, based on a least used/least interfered with channel algorithm in the absence of nearby APs.

21. The method of claim 1, further comprising:

said sensor gateway transmitting after determining that the channel is clear, wherein the channel must be clear for a predetermined amount of time.

22. The method of claim 1, further comprising:

said sensor gateway receiving sensor packets that are dynamically tagged by the sensors with a priority class, depending upon sensor type, to provide a higher priority value to the sensor'"'"'s data than otherwise would be assigned with a conventional classification of that data.

23. The method of claim 1, further comprising:

said sensor gateway providing contention-free access to the channel by the sensors for a transmit opportunity (TXOP) period in which a contention window (CW) is set according to the traffic expected in each access category, with a wider window needed for categories with heavier traffic.

24. The method of claim 1, further comprising:

said sensor gateway using network allocation vector (NAV) to limit a need for physical carrier-sensing by the sensors at an air interface to save power.

25. The method of claim 1, further comprising:

said sensor gateway setting a threshold that reduces a duration field which specifies a transmission time required by a sensor for a frame, during which time the selected channel is busy.

26. The method of claim 25, further comprising:

setting the threshold to zero, wherein the sensors repeatedly access the sensor gateway several times until communications are completed.

27. The method of claim 1, further comprising:

using Wi-Fi on a band which is different than that used by said sensors to connect the sensor gateway with the AP or gateway.

28. The method of claim 1, further comprising:

providing for communications with the sensors via a 2.4 GHz band, and establishing a connection between the sensor gateway and the AP or gateway via a 5 GHz band.

29. The method of claim 1, further comprising:

the sensor gateway only forwarding packets that are necessary to a sensor node and filtering unnecessary packets.

30. The method of claim 1, further comprising:

the sensor gateway reducing battery usage in the sensors by keeping a link to the sensors alive without requiring keep alive packets or other periodic transactions that are otherwise needed on an AP.

31. The method of claim 1, further comprising:

sensor gateway buffering data from the sensors and then sending the data to the backend connection;

wherein the sensors only require a software API for connecting directly to the sensor gateway and not to the backend connection.

32. The method of claim 1, further comprising:

the sensor gateway controlling a rate at which the sensor sends data to the sensor gateway or a rate at which the sensor gateway sends data to the backend connection;

wherein when the sensor gateway determines that queues are building up in the sensor gateway and it cannot send the data to backend connection to clear the queues, the sensor gateway sends a command to sensors to slow down the rate at which they send data to sensor gateway.

33. The method of claim 1, further comprising:

the sensor gateway controlling a rate at which the sensor sends data to the sensor gateway or a rate at which the sensor gateway sends data to the backend connection;

wherein when the sensor gateway determines that queues are building up in the sensor gateway and it cannot send the data to backend connection to clear the queues, the sensor gateway drops unnecessary data received from the sensors.

34. The method of claim 1, further comprising:

the sensor gateway controlling a rate at which the sensor sends data to the sensor gateway or a rate at which the sensor gateway sends data to the backend connection;

wherein when the sensor gateway determines that queues are building up in the sensor gateway and it cannot send the data to the backend connection to clear the queues, the sensor gateway the sensor gateway instructs the sensors with regard to parameters which include any of a compression parameter to use to send video, frame per second (fps), group of pictures (GOP) size, and target output bit rate.

35. The method of claim 1, further comprising:

said sensor gateway running backend connection management function for the sensors that comprise any of setting up connections, managing connection parameters, getting software upgrades, buffering when the Internet connection is slow, and buffering when sever is not responding.

36. The method of claim 1, further comprising:

implementing at least a portion of sensor memory and processing functions in the sensor gateway, instead of in the sensors.

37. The method of claim 1, further comprising:

the sensor gateway managing communications with the backend connection for the sensors to establish what data, controls, and commands are sent to the backend connection and what data, controls, and commands are not sent to the backend connection.

38. The method of claim 1, further comprising:

providing local data storage and/or data storage management functions on said sensor gateway;

wherein at least some sensor data is not stored via the backend connection.

39. The method of claim 1, further comprising:

the sensor gateway disconnecting sensors less often by increasing their time out values.

40. The method of claim 1, further comprising:

the sensor gateway reducing packet exchange with the sensors for authentication, encryption key exchange, and other security related mechanisms by keeping some of the information for a longer time and not redoing all of the steps every time the sensors disconnect and reconnect.

41. The method of claim 1, further comprising:

the sensor gateway assigning an IP address to a sensor and keeping the IP address;

wherein it is not necessary for the sensor to go through a DHCP protocol every time it disconnects and reconnects.

42. The method of claim 1, further comprising:

reducing a delay requirement for the sensors;

wherein the sensors check with the sensor gateway once every second, once every ten seconds, or less often.

43. The method of claim 1, further comprising:

the sensor gateway sending a beacon more frequently than one beacon every 100 ms;

wherein the wake up time is decreased for a sensor that has gone out of sync or a that does not receive a beacon because there is interference.

44. The method of claim 1, further comprising:

the sensor gateway using a beacon period that is not 100 ms/X or 100 ms*X to avoid collisions with nearby devices.

45. The method of claim 1, further comprising:

the sensor gateway increasing a beacon data rate.

46. The method of claim 1, further comprising:

using a predefined API between the AP or gateway and the sensor gateway to get a Wi-Fi MAC address by sending a command from the sensor gateway to the AP or gateway.

47. The method of claim 1, further comprising:

the sensor gateway providing policies that determine which sensor data should be transmitted out to the backend connection and which sensor data can be used only locally.

48. The method of claim 1, further comprising:

modifying default EDCA-related parameters at a sensor related application layer, wherein the application layer changes EDCA related parameters to achieve an acceptable delay when there is an unacceptable delay for high priority packets that are not transmitted.

49. The method of claim 1, further comprising:

the application layer issuing a channel change or triggering an automatic channel selection command to find a better channel when an unacceptable delay cannot be reached after changing EDCA parameters and other receiver and transmitter settings.

50. The method of claim 1, further comprising:

when the sensor finds that a channel is busy when it attempts to access the channel, the sensor picking a random number and, instead of listening for a clear channel and waiting for a back-off number to reach zero when the channel is clear, the sensor going to sleep, waking up after a random time and, if the channel is available when the sensor wakes up, the sensor transmitting immediately and without first doing back-off.