Methods for reconstructing missing packets in TTY over voice over IP transmission
First Claim
1. A process for error correction in a packetized TTY stream, comprising:
- receiving a first plurality of packets, each comprising audio information corresponding to at least a portion of one or more TTY tones in at least one sequence of TTY tones;
ordering the packets;
depacketizing the at least a portion of one or more TTY tones in the first plurality of packets to yield the at least one sequence of TTY tones;
determining when at least a portion of a TTY tone is missing from the at least one sequence of TTY tones;
when at least a portion of a TTY tone is missing, reconstructing the missing at least a portion of a TTY tone to form a reconstructed at least one sequence of TTY tones;
thereafter repacketizing the reconstructed at least one sequence of TTY tones to form a second plurality of packets; and
transmitting the second plurality of packets to a next node.
10 Assignments
0 Petitions
Accused Products
Abstract
A system for reconstructing missing packets in a packetized audio TTY stream that includes:
(a) an input 328 operable to receive a plurality of first packets, each comprising one or more TTY tones in a sequence of TTY tones; and
(b) a processor 332 operable to:
(i) order the packets;
(ii) depacketize the TTY tones in the plurality of first packets;
(iii) determine when a TTY tone is missing from the sequence of TTY tones;
(iv) when a TTY tone is missing, perform at least one of the following steps:
(1) determine the a TTY tone based on a portion of the tone contained in an adjacent packet; and
(2) determine the a TTY tone based on one of(i) a random or pseudo-random tone selection, (ii) a comparison of a first probability associated with a first TTY character generated from a first tone substituted for the missing a TTY tone with a second probability associated with a second TTY character generated from a second tone substituted for the missing TTY tone, and/or (iii) a comparison of a first ordering of TTY characters comprising the first TTY character and a second ordering of TTY characters comprising the second TTY character with a library of TTY character orderings.
40 Citations
65 Claims
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1. A process for error correction in a packetized TTY stream, comprising:
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receiving a first plurality of packets, each comprising audio information corresponding to at least a portion of one or more TTY tones in at least one sequence of TTY tones;
ordering the packets;
depacketizing the at least a portion of one or more TTY tones in the first plurality of packets to yield the at least one sequence of TTY tones;
determining when at least a portion of a TTY tone is missing from the at least one sequence of TTY tones;
when at least a portion of a TTY tone is missing, reconstructing the missing at least a portion of a TTY tone to form a reconstructed at least one sequence of TTY tones;
thereafter repacketizing the reconstructed at least one sequence of TTY tones to form a second plurality of packets; and
transmitting the second plurality of packets to a next node. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 35, 36)
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20. A process for error correction in a packetized TTY stream, comprising:
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receiving a plurality of first packets, each comprising audio information corresponding to at least a portion of one or more TTY tones in at least one sequence of TTY tones and each packet containing one of 10 ms, 20 ms, and 30 ms of one or more TTY tones;
ordering the packets;
depacketizing the at least a portion of one or more TTY tones in the plurality of first packets to yield the at least one sequence of TTY tones;
determining when at least a portion of a TTY tone is missing from the at least one sequence of TTY tones; and
when at least a portion of a TTY tone is missing, reconstructing the missing at least a portion of a TTY tone to form a reconstructed at least one sequence of TTY tones. - View Dependent Claims (21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34)
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37. A process for error correction in a packetized TTY stream, comprising:
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(a) receiving a plurality of first packets, each comprising audio information corresponding to at least a portion of one or more TTY tones in at least one sequence of TTY tones;
(b) ordering the packets;
(c) depacketizing the audio information in the plurality of first packets to yield the at least one sequence of TTY tones;
(d) determining when at least a portion of a TTY tone is missing from the at least one sequence of TTY tones; and
(e) when at least a portion of a TTY tone is missing, performing at least one of the following steps;
(1) determining the at least a portion of a TTY tone based on at least a portion of the tone contained in an adjacent packet; and
(2) determining the at least a portion of a TTY tone based on at least one of;
(i) a random or pseudo-random tone selection, (ii) a comparison of a first probability associated with a first TTY character generated from a first tone having a first frequency, the first tone being substituted for the missing at least a portion of a TTY tone, with a second probability associated with a second TTY character generated from a second tone having a second different frequency, the second tone being substituted for the missing at least a portion of a TTY tone, and (iii) comparison of a first ordering of TTY characters comprising the first TTY character and a second ordering of TTY characters comprising the second TTY character with a library of TTY character orderings. - View Dependent Claims (38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52)
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53. A system for error correction in a packetized TTY stream, comprising:
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(a) an input operable to receive a plurality of first packets, each comprising audio information corresponding to at least a portion of one or more TTY tones in least one sequence of TTY tones; and
(b) a processor operable to;
(i) order the packets;
(ii) depacketize the audio information in the plurality of first packets;
(iii) determine when at least a portion of a TTY tone is missing from the sequence of TTY tones; and
(iv) when at least a portion of a TTY tone is missing, perform at least one of the following steps;
(1) determine the at least a portion of a TTY tone based on at least a portion of the tone contained in an adjacent packet; and
(2) determine the at least a portion of a TTY tone based on at least one of (i) a random or pseudo-random tone selection, (ii) a comparison of a first probability associated with a first TTY character generated from a first tone of a first frequency, the first tone being substituted for the missing at least a portion of a TTY tone, with a second probability associated with a second TTY character generated from a second tone of a second different frequency, the second tone being substituted for the missing at least a portion of a TTY tone, and (iii) a comparison of a first ordering of TTY characters comprising the first TTY character and a second ordering of TTY characters comprising the second TTY character with a library of TTY character orderings. - View Dependent Claims (54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64)
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65. A process for error correction in a packetized TTY stream, comprising;
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(a) receiving a plurality of first packets, each comprising at least portions of one or more TTY tones;
(b) ordering the packets;
(c) depacketizing the at least portions of one or more TTY tones in each of the plurality of first packets to form at least one sequence of TTY tones;
(d) determining when at least a portion of a TTY tone is missing from the at least one sequence of TTY tones; and
(e) when the at least a portion of a TTY tone is missing, substituting an unknown identifier for at least one of a TTY character corresponding to the at least one sequence of TTY tones and the missing at least a portion of a TTY tone.
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Specification