System and method of enhancing WiFi real-time communications

• US 8,547,958 B2
• Filed: 02/22/2010
• Issued: 10/01/2013
• Est. Priority Date: 12/30/2005
• Status: Expired due to Fees

• Current Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Original Assignee: VTech Telecommunications Limited (VTech Holdings Ltd.)
• Inventors: Hundal, Sukhdeep S., Roodnick, Daniel, Cheng, Bennett
• Primary Examiner(s): PHUNKULH, BOB A
• Application Number:
  US12/709,591
• Publication Number:
  US 20100165900A1
• Time in Patent Office: 1,317 Days
• Field of Search: None
• US Class Current: 370/349
• 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, comprising:

a receiving device;

a sending device configured to transmit voice data over an RF link to the receiving device using an 802.11 protocol, wherein said sending device is configured to transmit the voice data by;

transmitting a first voice packet, a second voice packet different than the first voice packet, and a first frame check sequence packet in a first payload packet; and

transmitting the second voice packet and a second frame check sequence in a second payload packet after transmitting the first payload packet,

wherein the sending device is further configured to transmit a third voice packet in the second payload packet, wherein the third voice packet is different than the first voice packet and is different than the second voice packet.

2. The communications system of claim 1, wherein the receiving device comprises:

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.

3. The communications system of claim 2, wherein the receiving device further comprises:

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.

4. The communications system of claim 2, wherein the receiving device is configured to:

determine that the error is an address error;

determine whether the address is recoverable; and

correct the address error and forward the voice packets for delivery if the address is recoverable.

5. The communications system of claim 1, wherein the receiving device is configured to:

receive the data packet over an air interface;

detect an error in the data packet; and

correct the error and forward the data packet for delivery if the error is not an address error.

6. The communications system of claim 5, wherein the receiving device is configured to:

determine whether the error is an address error; and

correct the error and forward the data packet for delivery if the system determines that the address error is recoverable.

7. The communication system of claim 1, wherein the receiving device is configured to:

detect an address error;

determine that the address is recoverable; and

correct the address error and forward the data packet for delivery.

8. A communications system, comprising:

one or more WiFi terminal devices; and

an access point configured to;

establish an RF link with the one or more WiFi terminal devices using an 802.11 protocol over which data payloads are transferred;

cause the one or more WiFi terminal devices to transfer data payloads over the RF link such that each data payload comprises;

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; and

cause the one or more WiFi terminal devices to transmit the data payloads over the RF link via a plurality of frames such that each frame comprises;

a frame period that is a fixed and repeating time interval during which the RF 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 WiFi 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 WiFi terminal device.

9. The communications system of claim 8, wherein the one or more WiFi terminal devices are further configured to start a respective sleep period when the WiFi terminal device receives an end of service period bit from the access point.

10. The communications system of claim 8, wherein the one or more WiFi terminal devices are further configured to start a respective sleep period at a default sleep time if an end of service period bit is not received.

11. The communications system of claim 8, wherein the access point further configures a first active slot of the one or more active slots to allow a maximum amount of retries of data transmission between a first WiFi terminal device and the access point, wherein the first active slot does not overlap in time with any other slots arranged for communication with other active WiFi devices.

12. The communications system of claim 11, wherein the access point further causes each frame to further comprise:

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.

13. The communications system of claim 12, 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 a frame without adjusting the second wakeup time.

14. The communications system of claim 12, 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 be changed without adjusting the second wakeup time.

15. 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 data 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.

16. The method of claim 15, 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.

17. The method of claim 15, further comprising:

receiving a trigger; and

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

18. The method of claim 15, 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.

19. The method of claim 18, 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;

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

20. A communications system, comprising:

a receiving device;

a sending device configured to transmit voice data over an RF link to the receiving device using an 802.11 protocol, wherein said sending device is configured to transmit the voice data by;

transmitting a first voice packet, a second voice packet different than the first voice packet, and a first frame check sequence packet in a first payload packet; and

transmitting the second voice packet and a second frame check sequence in a second payload packet after transmitting the first payload packet,

wherein the sending device is further configured to;

calculate forward error correction bits based on the first voice packet, the second voice packet, and the first frame check sequence packet to obtain a forward error correction packet; and

transmit the first payload packet and the forward error correction packet via a data packet payload.

21. The communications system of claim 20, wherein the receiving device is configured to:

receive the data packet over an air interface;

detect an error in the data packet; and

correct the error and forward the data packet for delivery if the error is not an address error.

22. The communications system of claim 21, wherein the receiving device is configured to:

determine whether the error is an address error; and

correct the error and forward the data packet for delivery if the system determines that the address error is recoverable.

23. The communication system of claim 20, wherein the receiving device is configured to:

detect an address error;

determine that the address is recoverable; and

correct the address error and forward the data packet for delivery.