High-reliability computer interface for wireless input devices

• US 20050243059A1
• Filed: 03/16/2005
• Published: 11/03/2005
• Est. Priority Date: 03/16/2004
• Status: Abandoned Application

• Current Assignee: Jaalaa, Inc.
• Original Assignee: Jaalaa, Inc.
• Inventors: Anandakumar, Krishnasamy, Singamsetty, Suresh Kumar, Morris, Martin George, Chung Kwan, Dennis Ching, Law, Hock Thye
• Application Number:
  US11/081,381
• Publication Number:
  US 20050243059A1
• Time in Patent Office: Days
• US Class Current: 345/158
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 1/3215 Monitoring of peripheral devices
• CPC Class Codes: G06F 1/3237 by disabling clock generation or distribution
• CPC Class Codes: G06F 1/3259 Power saving in cursor control device, e.g. mouse, joystick, trackball
• CPC Class Codes: G06F 1/3271 Power saving in keyboard
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 2213/3814 Wireless link with a computer system port
• CPC Class Codes: G06F 3/0231 Cordless keyboards
• CPC Class Codes: G06F 3/03543 Mice or pucks G06F3/03541 takes precedence
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/0383 Signal control means within the pointing device
• CPC Class Codes: H04W 52/04 TPC
• CPC Class Codes: H04W 52/28 using user profile, e.g. mobile speed, priority or network state, e.g. standby, idle or non transmission
• CPC Class Codes: H04W 52/287 when the channel is in stand-by
• CPC Class Codes: H04W 52/48 during retransmission after error or non-acknowledgment
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A computing system wherein communication between a host computer and peripheral units, e.g. computer mouse and keyboard, is performed using RF signals. The host computer and the peripheral units each contain a transceiver for managing and transmitting the RF communication messages. An acknowledgement is sent by the receiving transceiver to the sending transceiver to signify that the message was successfully received. If no acknowledgement is received by the sending transceiver, a subsequent RF communication message is sent until an acknowledgement is received. A sleep mode is invoked between messages to conserve battery power in the peripheral units, and the peripheral units send a report message to the host when awaking periodically, or by a user demand, from the sleep mode signifying that the peripheral unit is active and ready to send or receive messages.

Claims

1. A method of communication between a media access control (MAC) and a radio unit within a transceiver, comprising:

a) writing a device ID of said receiving device to a radio unit;

b) enabling read mode, and receiving a message;

c) processing said message and preparing an acknowledgement (ACK) message;

d) disabling read mode;

e) setting up registers in said radio unit and enabling send mode; and

f) sending said ACK message and disabling send mode upon completion of sending said ACK message.

2. The method of claim 1, wherein processing said message includes a cyclical redundancy check (CRC) whereby said ACK message is blocked if the CRC finds said message to be bad.

3. A method for changing operating states of a wireless communication system under a control of a media access control (MAC) unit, comprising:

a) operating in a high data rate (HDR) mode when a received signal strength indicator (RSSI) is high and changing to a medium data rate (MDR);

b) selecting a next MDR channel when an acknowledgement (ACK) message timer expires;

c) changing to said HDR mode from said MDR mode when all available said MDR channels have been tried and said ACK timer expires for each said available MDR channels; and

d) changing to said HDR mode when RSSI is low and operating in said HDR mode when RSSI is low.

4. The method of claim 3, wherein said RSSI is monitored by a radio frequency unit coupled to said MAC and provides an indication of the strength of other signals, or noise, operating on said MDR channel.

5. The method of claim 3, wherein said next MDR channel is selected from a plurality of channels in which no two adjacent channels are selected in an immediate sequence to reduce the possibility that unwanted signals on a first selected channel being present on a second channel.

6. A method for collision avoidance and information handling, comprising;

a) preparing to send a message from a peripheral RF transceiver;

b) enabling an RF receiver and waiting for locking of a phase lock loop;

c) performing a clear channel assessment CCA by the RF receiver;

d) performing a random backoff if a channel is busy and then switch to a transmit mode;

e) awaiting a window of time T, then check the CCA report from said RF receiver, if channel is not busy, then switch to transmit mode, otherwise if channel is busy, perform a random backoff, then switch to transmit mode;

f) transmitting said message and after switching to said RF receiver to wait for an acknowledgement (ACK) that the message transmitted was received and ending if an ACK is received;

g) returning to step c) if there is no ACK and a number of transmissions has not exceeded a maximum;

h) exiting process if the number of transmissions has exceeded the maximum and waiting for a new message.

7. The method of claim 6, wherein said CCA is a measurement of a level of interference within said channel.

8. The method of claim 6, wherein said random backoff is a function a size of said message, a transmitter and a receiver latency, a time to process for preparing to send said message and switching time of said phase lock loop.

9. The method of claim 6, wherein said window of time T is a function of a switching time of said phase lock loop, a time to process for preparing to send said message and a transmission latency.

10. A method for dynamically adjusting a clear channel assessment (CCA), comprising:

a) setting a CCA threshold to a default value;

b) measuring performance and backoff rates for a plurality of sent radio frequency (RF) messages;

c) increasing said CCA threshold to threshold=threshold plus a specified decibel level if the backoff rate is greater than a first backoff amount and said performance is less than a first performance amount, and returning to step b) to measure performance and backoff rates; and

d) decreasing said CCA threshold to threshold=threshold minus a specified decibel level if the backoff rate is less than a second backoff amount and said performance is greater than a second performance amount, and returning to step b) to measure performance and backoff rates.

11. The method of claim 10, wherein said backoff is a time delay before resending an RF message thereby breaking deadlocks caused by simultaneous RF transmissions.

12. The method of claim 10, wherein said CCA is a measurement of a level of interference within a communication channel.

13. A method for interference handling, comprising:

a) receiving a received signal strength indication (RSSI) at an radio frequency (RF) transceiver;

b) applying a high data rate (HDR) or a medium data rate (MDR) when said RSSI is high, which signifies a relatively high degree of RF interference; and

c) checking conditions to go between a spreading mode and an MDR mode when said RSSI is low, which signifies a relatively low degree of RF interference.

14. The method of claim 13, wherein said HDR is a default data rate mode.

15. The method of claim 13, wherein said MDR is used when there is a strong interference such as might be caused by a citizen band radio.

16. The method of claim 13, wherein said spreading mode is used when there is interference from devices similar to said RF transceiver.

17. A method for switching between a high data rate (HDR) and a medium data rate (MDR) at an RF transceiver, comprising:

a) continuing use of a HDR when a received signal strength indicator (RSSI) is low;

b) switching to a MDR when the RSSI is high and resetting a data encryption;

c) listening for a first period of time on a first channel of a plurality of communication channels after switching to the MDR mode;

d) continuing to communicate in said first channel when said RF message is received, listening for a second period of time, and receiving additional RF messages;

e) switching to a second channel of said plurality of communication channels and resetting said encryption after listening and receiving no RF messages on said first channel, then returning to step c);

f) switching the HDR mode after switching through all available channels of said plurality of channels when in the MDR mode until said all available channels have been used and no RF messages have been received; and

g) switching to the HDR mode and resetting the encryption when the RSSI is low.

18. The method of claim 17, wherein switching to the HDR model further comprises:

a) resetting encryption and listening for a third period of time; and

b) switching to the MDR mode and changing encryption when RSSI is high and no RF message is received during said third period of time.

19. The method of claim 18, wherein said third period of time is for a plurality of seconds.

20. The method of claim 17, wherein said first and second periods of time is for a plurality of milliseconds.

21. The method of claim 17, wherein said plurality of channel are selected in a sequence where no two channels having adjacent frequencies are selected as a next channel from said plurality of channels.

22. A method for performing in a medium data rate (MDR) mode, comprising;

a) transmitting a first RF message in a MDR mode over a first communication channel and listening for an first acknowledgement (ACK);

b) remaining in said first communication channel if said first ACK is received, transmitting a second RF message and waiting for a second ACK;

c) remaining in said first communication channel if said second ACK is received;

d) retransmitting said second RF message as a first retransmission of said second RF message and waiting for a third ACK and remaining in said first communication channel if said third ACK is received; and

e) retransmitting said second RF message as a second retransmission of the second RF message if a first timer has not expired and if said third ACK is not received, otherwise switch a second communication channel and reset encryption.

23. The method of claim 22, wherein transmitting said first RF message further comprises:

a) switching to said second communication channel and resetting encryption if said first ACK of the first RF message is not received;

b) retransmitting said first RF message as a first retransmission of said first RF message and remaining in said second communication channel if said ACK to said first retransmission of said RF message is received;

c) switching to a third communication channel, resetting encryption, retransmitting said first RF message as a second retransmission if a second timer has not expired; and

d) switching to a high data rate (HDR), resetting encryption mode, retransmitting said first RF message as a third retransmission of said first RF message and listening for said ACK for the third retransmission and returning to said MDR mode if no said ACK received, a third timer has expired and a received signal strength indicator is high.

24. The method of claim 23, wherein said second timer is in the order of seconds and said third timer is in the order of milliseconds.

25. The method of claim 22, wherein said first timer is in the order of milliseconds.

28. The method of claim 25, wherein said second period of time is an amount of time in which the host is awake.

29. The method of claim 25, wherein said third period of time necessary to receive said data packet and respond with an acknowledgement.

26. A method for a host transceiver in suspend mode, comprising:

a) waiting for a first period of time and entering an awake state;

b) listening for RF messages during a second period of time, detecting no valid header data, entering a sleep state, and returning to step a);

c) validating a header of a message, listening for a third period of time, receiving no data packet, entering a sleep state and returning to step a); and

d) validating said header of a message, listening for a third period of time, receiving a packet of data, remaining in said awake state and returning to step b).

27. The method of claim 26, wherein said first period of time is an amount of time between said awake states.

30. A method for modifying messaging protocol of a mouse transceiver upon entry of a host transceiver into a suspend mode, comprising:

a) transmitting a first message from a mouse to a host transceiver and if an acknowledgement ACK is received by said mouse continue transmitting additional messages;

b) re-transmitting said first message if ACK is received, then continue transmitting additional messages;

c) re-transmitting said first message if ACK not received and if a predefined number of retransmissions has not been exceeded;

d) sending a link reset from said mouse to said host transceiver if a predefined number of retransmissions has not been exceeded;

e) receiving ACK from said host transceiver for said link reset and returning to transmitting messages from said mouse to said host;

f) sending said link reset from said mouse to said host transceiver if no ACK for link reset received from said host transceiver and if said predetermined number of said link reset not exceeded;

then g) transmitting a second message if said second message packet is in a queue; and

h) sending said link reset for a period of time if no said message packet is in the queue.

31. The method of claim 30, wherein said period of time is a plurality of milliseconds that is reconfigurable.

32. A computing system using radio frequency (RF) signals to communicate between a plurality of computing units, comprising:

a) a plurality of transceivers located in a plurality of computing units and communicating between said plurality of computing units with RF signals;

b) each transceiver of said plurality of transceivers contain a software ROM that controls operations of said each transceiver; and

c) a software patch EEPROM added to said each transceiver to allow modifications and additions to commands contained within said software ROM.

33. The computing system of claim 32, wherein said plurality of computing units comprise a host computer, a keyboard and a mouse.

34. The computing system of claim 32, wherein said each transceiver controls communications and is personalized to the characteristics of each computing unit of said plurality of computing units with said ROM and said EEPROM.

35. A method for using a patch EEPROM for controlling operations of a radio frequency (RF) transceiver, comprising:

a) initializing a transceiver in a computing unit;

b) copying an EEPROM into RAM if a patch EEPROM exists then resuming initialization from a ROM; and

c) continuing operation using said ROM if a patch EEPROM does not exist.

36. The method of claim 35, wherein said ROM provides commands for operating said transceiver.

37. The method of claim 35, wherein said EEPROM provides modified and additional commands for operating said transceiver.

38. A method for using null function pointers to substitute a new function into an operation of a radio frequency (RF) transceiver, comprising:

a) calling a substitute function if a function pointer is not equal to null and continuing operation of a RF transceiver; and

b) running an original function if said function pointer is null and continuing operation of said RF transceiver.

39. The method of claim 38, wherein said substitute function replaces a default function when a default pointer is replaced with said function pointer.

40. The method of claim 38, wherein said substitute function resides in memory and is loaded into said memory upon power-on of said transceiver.