Codecs with suppression of multiple encoding/decodings across a connection

Claim 2

A codec for use in a system in which said codec (134) is connected to a communication endpoint (114,115) via a transmission path (169) said codec being adapted to generate an output digital signal destined for said communication endpoint in response to a digital input signal, said output signal representing intelligence to be communicated to said endpoint and said input signal representing said intelligence in coded form, characterised by first means (214) for forming a determination as to whether said transmission path includes means (136) for decoding said output signal, second means (231) operative when said determination is that said path does not include a means for decoding said output signal for generating as said output signal a decoded version of said intelligence, and third means (232) operative when said determination is that said path does include a means for decoding said output signal for generating as said output signal a signal in which said input signal is embedded.

Claim 3

A codec as claimed in claim 1 including means for receiving from said path a second input signal, said second input signal representing intelligence originating from said endpoint, and wherein said first means forms a determination that said path includes a means for decoding said output signal in response to the presence in said second input signal of a predefined supervisory signal.

Claim 4

A codec as claimed in claim 2 including means for including within said output signal a supervisory signal indicative of the presence of said codec.

Claim 5

A codec as claimed in claim 2 or claim 3 wherein said first input and output signals are at first and second bit rates respectively, said first bit rate being less than said second bit rate and wherein said third means generates said output signal by adding place-holder bits to said first input signal.

Claim 6

A codec as claimed in claim 4 wherein individual ones of said place-holder bits constitute a supervisory signal indicative of the presence of said codec.

Claim 7

A codec for use in a system in which said codec (134) is connected to a communication endpoint (114,115) via a transmission path (169) said codec being adapted to generate a digital output signal in response to a digital input signal received over said transmission path, said input signal representing intelligence originating from said communication endpoint and said output signal representing said intelligence in coded form, characterised by first means (214) for forming a determination as to whether said input signal has embedded therein a coded version of said intelligence, second means (211) operative when said determination is that said input signal does not have embedded therein a coded version of said intelligence for generating as said output signal a coded version of said intelligence, and third means (212) operative when said determination is that said input signal does have embedded therein a coded version of said intelligence for generating as said output signal the portion of said input signal comprising said embedded coded version.

Claim 8

A codec for use in a system in which said codec (134) is connected to a communication endpoint (114,115) via a transmission path (169) said codec being adapted to generate a digital output signal in response to a digital input signal received over said transmission path, said input signal representing intelligence originating from said communication endpoint and said output signal representing said intelligence in coded form, characterised by first means (214) for forming a determination as to whether said input signal has embedded therein a coded version of said intelligence, second means (211) operative when said determination is that said input signal does not have embedded therein a coded version of said intelligence for generating as said output signal a coded version of said intelligence, and third means (212) operative when said determination is that said input signal does have embedded therein a coded version of said intelligence for generating as said output signal the portion of said input signal comprising said embedded coded version.

Claim 9

A codec as claimed in claim 6 wherein said first means forms a determination that said input signal has embedded therein a coded version of said intelligence in response to the presence in said input signal of a predefined supervisory signal.

Claim 10

A codec for use in a system in which said codec is connected to first (111) and second (114,115) communication endpoints via first (173) and second (169) transmission paths, respectively, said codec being adapted to generate first and second digital output signals in response to first and second digital input signals, respectively, said first and second input signals representing intelligence originating from said first and second communication endpoints, respectively, said first and second output signals representing intelligence destined for said second and first communication endpoints, respectively, and said first input and second output signals respectively representing in coded form the intelligence represented by said first output and second input signals characterised by first means (214) for forming a determination as to whether said second transmission path includes both a means (136) for decoding said first output signal and a means (135) for embedding in said second input signal a coded version of the intelligence originating from said second endpoint, second means (231,211) operative in response to a negative such determination for generating as said first output signal a decoded version of the intelligence represented by said first input signal and for generating as said second output signal a coded version of the intelligence represented by said second input signal, and third means (232,212) operative in response to a positive such determination for generating as said first output signal a signal in which said first input signal is embedded and for generating as said second output signal the portion of said second input signal comprising said embedded coded version of the intelligence originating from said second endpoint.

Claim 11

A codec for use in a system in which said codec is connected to first (111) and second (114,115) communication endpoints via first (173) and second (169) transmission paths, respectively, said codec being adapted to generate first and second digital output signals in response to first and second digital input signals, respectively, said first and second input signals representing intelligence originating from said first and second communication endpoints, respectively, said first and second output signals representing intelligence destined for said second and first communication endpoints, respectively, and said first input and second output signals respectively representing in coded form the intelligence represented by said first output and second input signals characterised by first means (214) for forming a determination as to whether said second transmission path includes both a means (136) for decoding said first output signal and a means (135) for embedding in said second input signal a coded version of the intelligence originating from said second endpoint, second means (231,211) operative in response to a negative such determination for generating as said first output signal a decoded version of the intelligence represented by said first input signal and for generating as said second output signal a coded version of the intelligence represented by said second input signal, and third means (232,212) operative in response to a positive such determination for generating as said first output signal a signal in which said first input signal is embedded and for generating as said second output signal the portion of said second input signal comprising said embedded coded version of the intelligence originating from said second endpoint.

Claim 12

A codec as claimed in claim 8 wherein said first input and second output signals are at a first bit rate and said first output and second input signals are at a second bit rate greater than said first bit rate, and wherein said third means generates said first output signal by adding place-holder bits to said first input signal and generates said second output signal by stripping place-holder bits from said second input signal.

Claim 13

A codec as claimed in claim 8 or claim 9 wherein said first means forms said determination in response to the presence or absence in said second input signal of a predefined supervisory signal.

Claim 16

A method as claimed in claim 11 wherein said codec further includes means for receiving from said path a second input signal, said second input signal representing intelligence originating from said endpoint, and wherein in said determination forming step a determination is formed that said path includes a means for decoding said first output signal in response to the presence in said second input signal of a predefined supervisory signal.

Claim 17

A method as claimed in claim 12 wherein in each of said generating steps a supervisory signal indicative of the presence of said codec is included within said output signal.

Claim 18

A method as claimed in claim 12 or claim 13 wherein said first input and output signals are at first and second bit rates respectively, said first bit rate being less than said second bit rate and wherein in the second of said generating steps said output signal is generated by adding place-holder bits to said first input signal.

Claim 19

A method as claimed in claim 14 wherein individual ones of said place-holder bits constitute a supervisory signal indicative of the presence of said codec.

Claim 22

A method as claimed in claim 16 wherein in said forming step a determination that said input signal has embedded therein a coded version of said intelligence is formed in response to the presence in said input signal of a predefined supervisory signal.