SYSTEM AND METHOD OF ENHANCING WIFI REAL-TIME COMMUNICATIONS

• US 20100165900A1
• Filed: 02/22/2010
• Published: 07/01/2010
• Est. Priority Date: 12/30/2005
• Status: Active Grant

• Current Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Original Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Inventors: Cheng, Bennett, HUNDAL, SUKHDEEP S., Roodnick, Daniel
• Granted Patent: US 8,547,958 B2
• Time in Patent Office: Days
• US Class Current: 370/311
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/0083 Formatting with frames or packets; Protocol or part of protocol for error control
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04W 24/02 Arrangements for optimising operational condition
• CPC Class Codes: H04W 80/00 Wireless network protocols or protocol adaptations to wireless operation
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

Systems and methods of enhanced real-time communications between WiFi devices. In one embodiment of the present invention a method for enhanced payload protection in a WiFi system includes transmitting multiple copies of data packets in successive frame body transmissions. In another embodiment, a method for enhanced communications over a WiFi link includes examining a unit ID packet to determine a destination of a data payload when errors are detected in IP and/or MAC headers. If a destination is determined, the packet is corrected and forwarded to the device based on the unit ID determination. In another embodiment, a method for enhanced real-time communications in a WiFi network includes establishing a communications frame that includes an active timeslot, preferably based on U-APSD, for a WiFi device to use for transmission of successive audio data packets transmitted between the WiFi handset and AP.

Claims

1. A communications system configured to transmit over an RF link using an 802.11 protocol, the communications system having a data payload structure comprising:

a first voice packet slot configured to receive a first voice packet at a first time;

a second voice packet slot configured to receive a second voice packet different from the first voice packet at the first time; and

a frame check sequence packet, wherein the first voice packet slot is configured to receive the second voice packet at a second time subsequent to the first time.

2. The communications system of claim 1, further comprising a third voice packet slot configured to receive a third voice packet at the first time, wherein the second voice packet slot is configured to receive the third voice packet at the second time.

4. The communications system of claim 1, further comprising means for receiving the first and second voice packets over an air interface;

means for detecting an error in one or both of the packets;

means for correcting the error and forwarding the voice packets for delivery if the error is not an address error.

5. The communications system of claim 4, further comprising;

means for determining that the error is an address error; and

means for correcting the error and forwarding the voice packets for delivery if the address error is determined to be recoverable.

6. The communications system of claim 4, wherein the system determines that the error is an address error and determines whether the address is recoverable;

and

corrects the address error and forwards the voice packets for delivery if the address is recoverable.

3. A communications system configured to transmit over an RF-link using an 802.11 protocol in which a data packet structure comprises:

a data packet transmitted as part of an 802.11 payload packet; and

a forward error correction packet having forward error correction bits calculated from the data packet by a transmitter of the communications system.

7. The communications system of claim 3, further comprising means for receiving the data packet over an air interface;

means for detecting an error in the data packet;

means for correcting the error and forwarding the data packet for delivery if the error is not an address error.

8. The communications system of claim 3, wherein the system determines whether the error is an address error, and corrects the error and forwards the data packet for delivery if the system determines that the address error is recoverable.

9. The communication system of claim 3, further comprising;

means for determining that the error is an address error;

means for determining that the address is recoverable; and

means for correcting the address error and forwarding the data packet for delivery.

10. A communications system configured to transmit over an RF link using an 802.11 protocol, the communications system having a data payload structure comprising:

a first voice packet slot configured to receive a first voice packet at a first time;

a second voice packet slot configured to receive a second voice packet different from the first voice packet at the first time;

a frame check sequence packet, wherein the first voice packet slot is configured to receive the second voice packet at a second time subsequent to the first time;

wherein the communication system has a frame structure for transmitting data payloads between an access point and one or more WiFi terminal devices, the frame structure comprising;

a frame period that is a fixed and repeating time interval during which a WiFi link is operable between the access point and WiFi terminal devices;

one or more of the active slots, each active slot dedicated to a respective WiF terminal device, where the respective WiFi terminal device maintains an active state only during the respective active slots;

a sleep period associated with each WiFi terminal device, wherein the respective WiFi terminal device maintains a low or standby power state in the sleep period; and

a command slot configured for transmission of a command packet between the access point and the WiF terminal device.

11. The communications system of claim 10, wherein the sleep period is configured to start when the WiFi terminal device receives an end of service period bit from the access point.

12. The communications system of claim 10, wherein the sleep period is configured to start at a default sleep time if an end of service period bit is not received.

13. The communications system of claim 10, wherein a first active slot of the one or more active slots is configured to allow a maximum amount of retries of data transmission between a first WiFi terminal device and an access point, wherein the first active slot does not overlap in time with any other slots arranged for communication with other active WiFi devices.

14. The communications system of claim 13, wherein the frame structure comprises:

a first wakeup time that marks a start of a first active slot corresponding to an active period of a first WiFi terminal device; and

a second wakeup time that marks a start of a second active slot corresponding to an active period of a second WiFi terminal device,

wherein the first and second active slots do not overlap in time.

15. The communications system of claim 14, wherein the first wakeup time and second wakeup time are mutually arranged such that additional active time slots for additional WiFi devices can be incorporated in the frame structure without adjusting the second wakeup time.

16. The communications system of claim 14, wherein the first wakeup time and second wakeup time are mutually arranged such that a transmission rate between active WiFi terminal devices and the access point can changed be changed without adjusting the second wakeup time.

17. A method for transmitting data over an RF-link using an 802.11 protocol which comprises:

transmitting a data packet as part of an 802.11 payload packet;

transmitting a forward error correction packet having forward error correction bits calculated from the data packet;

receiving a real-time communications request from a first WiFi device;

establishing a real time communications date frame structure corresponding to a plurality of repeating data frames during communications between the first WiFi device and an access point;

reserving a first default active slot comprising a first wakeup time and first default sleep time within each repeating data frame and initiates an active period of the first WiFi device during each repeating data frame at the wakeup time; and

terminating the active period when an end of service period bit is received.

18. The method of claim 17, further comprising:

establishing a sleep trigger time at which the system is configured to deliver the end of service bit to the first WiFi device; and

terminating the active period at a default sleep time if the end of service bit is not received before the default sleep time.

19. The method of claim 17, further comprising:

receiving a trigger; and

delivering buffered data to the WiFi device during the active period.

20. The method of claim 17, further comprising:

receiving a second real time communication request from a second WiFi device; and

reserving a second default active slot for a second WiFi device, wherein the first and second default active slots do not overlap in time, wherein the second default active slot comprises a second wakeup time and second default sleep time.

21. The method of claim 20, further comprising:

receiving a third request for real-time communications from a third WiFi device;

adjusting the second default sleep time; and

reserving a third default active slot for the third WiFi device corresponding to a third wakeup time and a third default sleep time, wherein the adjusted second default sleep time is before the third wakeup time,

and wherein the unadjusted second default sleep time is after the third wakeup time.