Phase optimization for wireless KVM transmission

• US 7,246,183 B2
• Filed: 09/23/2004
• Issued: 07/17/2007
• Est. Priority Date: 11/14/2003
• Status: Expired due to Fees

• Current Assignee: Avocent Huntsville Corporation (Vertiv Holdings Co.)
• Original Assignee: Avocent California Corporation (Vertiv Holdings Co.)
• Inventors: Li, Sheng, Moore, Richard L., Covington, C. David, Lally, Charles, Huntly-Playle, Iain
• Primary Examiner(s): Park; Ilwoo
• Application Number:
  US10/947,163
• Publication Number:
  US 20050108451A1
• Time in Patent Office: 1,027 Days
• Field of Search: None
• US Class Current: 710/62
• CPC Class Codes: G06F 3/023 Arrangements for converting discrete items of information into a coded form, e.g. arrangements for interpreting keyboard generated codes as alphanumeric codes, operand codes or instruction codes
• CPC Class Codes: G06F 3/038 Control and interface arrangements therefor, e.g. drivers or device-embedded control circuitry
• CPC Class Codes: G06F 3/1454 involving copying of the display data of a local workstation or window to a remote workstation or window so that an actual copy of the data is displayed simultaneously on two or more displays, e.g. teledisplay
• CPC Class Codes: G09G 2340/0485 Centering horizontally or vertically
• CPC Class Codes: G09G 5/008 Clock recovery

Abstract

In a wireless keyboard-video-mouse (“KVM”) system in which a remote computer accesses the video output data of a target computer, a method of providing video data from the target computer to the remote computer, includes obtaining an analog video signal from a target computer; disabling data compression of the video signal; determining a first phase (P) for analog-to-digital (A/D) conversion of the video signal; beginning compression of the video signal; and adjusting the first phase of the A/D conversion to produced a second phase (P′), based, at least in part, on a number of segments required to transmit the compressed video signal.

Claims

1. In a wireless keyboard-video-mouse (“

KVM”

) system in which a remote computer accesses the video output data of a target computer, a method of providing video data from the target computer to the remote computer, the method comprising;

obtaining an analog video signal from a target computer;

disabling data compression of the video signal;

determining a first phase for analog-to-digital (A/D) conversion of the video signal;

beginning compression of the video signal; and

adjusting the first phase of the A/D conversion to produced a second phase, based, at least in part, on a quality measure of the compressed video signal.

2. A method as in claim 1 wherein the quality measure includes a number of segments required to transmit the compressed video signal.

3. A method as in claim 2 wherein the adjusted phase setting selected is one which produces the lowest segment count of a plurality of tested phases.

4. A method as in claim 1 wherein the first phase is phase P, the method further comprising:

testing phases P−

2, P−

1, P, P+1, and P+2; and

selecting as the adjusted phase, that phase from the phases P−

2, P−

1, P, P+1, and P+2 that produces the lowest segment count.

5. In a wireless keyboard-video-mouse (“

KVM”

) system in which a remote computer accesses the video output data of a target computer, a method of providing video data from the target computer to the remote computer, the method comprising;

(A) obtaining an analog video signal from a target computer;

(B) disabling data compression of the video signal;

(C) determining a first phase (P) for analog-to-digital (A/D) conversion of the video signal;

(D) beginning compression of the video signal; and

(E) adjusting the first phase of the A/D conversion to produced a second phase (P′

), based, at least in part, on a number of segments required to transmit the compressed video signal, wherein the adjusted phase setting selected is one which produces the lowest segment count of a plurality of tested phases, the adjusting comprising;

(e1) testing phases P−

2, P−

1, P, P+1, and P+2; and

(e2) selecting as the adjusted phase, that phase from the phases P−

2, P−

1, P, P+1, and P+2 that produces the lowest segment count.