# US 8,751,223 B2 · Encoded packet selection from a first voice stream to create a second voice stream > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,751,223 B2 - Document ID: US8751223B2 - Status: Granted - Kind: B2 - Application number: 13/068,924 - Filed: 2011-05-24 - Published: 2012-11-29 - Granted: 2014-06-10 - Earliest claimed: 2011-05-24 - Assignees: Alcatel Lucent - Applicants: Jeffrey A. Hiltner; Alan H. Matten; Dale R. Schumacher; Albert J. Such - Inventors: Jeffrey A. Hiltner; Alan H. Matten; Dale R. Schumacher; Albert J. Such - Web page: https://patentgrep.com/patent/US8751223B2 ## CPC - H04L 65/70: Media network packetisation - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) ## Abstract In one implementation, a first voice stream for a packet-switched call is received from a calling party. The first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call. A subset of encoded packets are selected from the plurality of encoded packets to create a second voice stream that conforms to a second silence suppression scheme. The second voice stream comprises the subset of encoded packets. The first silence suppression scheme is distinct from the second silence suppression scheme. The second voice stream is forwarded toward a called party for the packet-switched call. ## Claims ### Claim 1 A method, comprising the steps of: receiving a first voice stream for a packet-switched call from a calling party, wherein the first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call; selecting a subset of encoded packets from the plurality of encoded packets to create a second voice stream that conforms to a second silence suppression scheme, wherein the second voice stream comprises the subset of encoded packets, wherein the first silence suppression scheme is distinct from the second silence suppression scheme; and forwarding the second voice stream toward a called party for the packet-switched call, wherein the first voice stream comprises a first discontinuous transmission (DTX) stream and wherein the second voice stream comprises a second DTX stream, wherein the step of selecting the subset of encoded packets comprises the step of: selecting the subset of encoded packets according to the second silence suppression scheme, such that the second DTX stream conforms to the second silence suppression scheme, wherein the first and second silence suppression schemes comprise respective first and second silence suppression intervals; wherein the plurality of encoded packets comprise at least one of: a synchronous packet, sent upon the first silence suppression interval according to the first silence suppression scheme, or an asynchronous packet, sent independently of the first silence suppression interval according to the first silence suppression scheme; wherein the step of selecting the subset of encoded packets comprises the step of: selecting, upon the second silence suppression interval, a most recently received packet of the at least one of the synchronous packet or the asynchronous packet, wherein the subset of encoded packets comprises the most recently received packet; wherein the step of forwarding the second DTX stream comprises the step of: forwarding the most recently received packet upon the second silence suppression interval. ### Claim 2 (depends on 1) The method of claim 1, wherein the first silence suppression interval is distinct from the second silence suppression interval. ### Claim 3 (depends on 1) The method of claim 1, wherein the first silence suppression scheme conforms to an Enhanced Variable Rate Codec Narrowband-Wideband (EVRC-NW) standard; wherein the synchronous packet comprises a rate ⅛th non-critical packet of the EVRC-NW standard; wherein the second silence suppression scheme conforms to an Enhanced Variable Rate Codec B (EVRC-B) standard. ### Claim 4 (depends on 3) The method of claim 3, wherein the step of receiving the voice stream comprises the step of: receiving the voice stream from a cellular base station that employs the EVRC-NW standard; wherein the step of forwarding the second DTX stream comprises the step of: forwarding the second DTX stream toward a Transcoder Free Operation (TrFO) network that employs the EVRC-B standard. ### Claim 5 A method, comprising the steps of: receiving a first voice stream for a packet-switched call from a calling party, wherein the first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call; selecting a subset of encoded packets from the plurality of encoded packets to create a second voice stream that conforms to a second silence suppression scheme, wherein the second voice stream comprises the subset of encoded packets, wherein the first silence suppression scheme is distinct from the second silence suppression scheme; and forwarding the second voice stream toward a called party for the packet-switched call, wherein the first voice stream comprises a first discontinuous transmission (DTX) stream and wherein the second voice stream comprises a second DTX stream, wherein the step of selecting the subset of encoded packets comprises the step of: selecting the subset of encoded packets according to the second silence suppression scheme, such that the second DTX stream conforms to the second silence suppression scheme, wherein the step of selecting the subset of encoded packets comprises the steps of: receiving one or more parameters of the second silence suppression scheme; and selecting the subset of encoded packets based on the one or more parameters. ### Claim 6 (depends on 5) The method of claim 5, further comprising the steps of: receiving one or more parameters of a third silence suppression scheme that is distinct from the first and second silence suppression schemes; storing the one or more parameters of the third silence suppression scheme; and selecting the subset of encoded packets based on the one or more parameters of the third silence suppression scheme. ### Claim 7 An apparatus, comprising: a silence suppression interface component configured to receive a first voice stream for a packet-switched call from a transmitting device; wherein the first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call; wherein the silence suppression interface component is configured to select a subset of encoded packets from the plurality of encoded packets to create a second voice stream that conforms to a second silence suppression scheme; wherein the second voice stream comprises the subset of encoded packets; wherein the first silence suppression scheme is distinct from the second silence suppression scheme; wherein the silence suppression interface component is configured to forward the second voice stream toward a receiving device for the packet-switched call; wherein the first voice stream comprises a first discontinuous transmission (DTX) stream; wherein the second voice stream comprises a second DTX stream; wherein the first and second silence suppression schemes comprise respective first and second silence suppression intervals; wherein the plurality of encoded packets comprise at least one of: a synchronous packet, sent upon the first silence suppression interval according to the first silence suppression scheme, or an asynchronous packet, sent independently of the first silence suppression interval according to the first silence suppression scheme; wherein the silence suppression interface component is configured to select a most recently received packet of the at least one of the synchronous packet or the asynchronous packet upon the second silence suppression interval. ### Claim 8 (depends on 7) The apparatus of claim 7, wherein the first silence suppression interval is distinct from the second silence suppression interval. ### Claim 9 (depends on 8) The apparatus of claim 8, wherein the second voice stream is forwarded via the silence suppression interface component toward the receiving device through a packet-switched network; wherein the packet-switched network employs the second silence suppression scheme. ### Claim 10 (depends on 8) The apparatus of claim 8, wherein the first silence suppression scheme conforms to an Enhanced Variable Rate Codec Narrowband-Wideband (EVRC-NW) standard; wherein the synchronous packet comprises a rate ⅛th non-critical packet of the EVRC-NW standard; wherein the second silence suppression scheme conforms to an Enhanced Variable Rate Codec B (EVRC-B) standard. ### Claim 11 An apparatus, comprising: a silence suppression interface component configured to receive a first voice stream for a packet-switched call from a transmitting device; wherein the first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call; wherein the silence suppression interface component is configured to select a subset of encoded packets from the plurality of encoded packets to create a second voice stream that conforms to a second silence suppression scheme; wherein the second voice stream comprises the subset of encoded packets; wherein the first silence suppression scheme is distinct from the second silence suppression scheme; wherein the silence suppression interface component is configured to forward the second voice stream toward a receiving device for the packet-switched call; wherein the silence suppression interface component is configured to mediate between a first set of a number Y silence suppression schemes and a second set of a number Z silence suppression schemes; wherein the first set of silence suppression schemes comprises the first silence suppression scheme; wherein the second set of silence suppression schemes comprises the second silence suppression scheme. ### Claim 12 An article, comprising: one or more non-transitory processor-readable media storing instructions which, when executed by a processor, cause the processor to perform a method comprising the steps of: receiving a first voice stream for a packet-switched call from a calling party, wherein the first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call; selecting a subset of encoded packets from the plurality of encoded packets to create a second voice stream that conforms to a second silence suppression scheme, wherein the second voice stream comprises the subset of encoded packets, wherein the first silence suppression scheme is distinct from the second silence suppression scheme; and forwarding the second voice stream toward a called party for the packet-switched call, wherein the first voice stream comprises a first discontinuous transmission (DTX) stream and wherein the second voice stream comprises a second DTX stream, wherein the step of selecting the subset of encoded packets comprises the step of: selecting the subset of encoded packets according to the second silence suppression scheme, such that the second DTX stream conforms to the second silence suppression scheme, wherein the first and second silence suppression schemes comprise respective first and second silence suppression intervals; wherein the plurality of encoded packets comprise at least one of: a synchronous packet, sent upon the first silence suppression interval according to the first silence suppression scheme, or an asynchronous packet, sent independently of the first silence suppression interval according to the first silence suppression scheme; wherein the step of selecting the subset of encoded packets comprises the step of: selecting, upon the second silence suppression interval, a most recently received packet of the at least one of the synchronous packet or the asynchronous packet, wherein the subset of encoded packets comprises the most recently received packet; wherein the step of forwarding the second DTX stream comprises the step of: forwarding the most recently received packet upon the second silence suppression interval. ### Claim 13 (depends on 12) The article of claim 12, wherein the first silence suppression interval is distinct from the second silence suppression interval. ### Claim 14 A method, comprising the steps of: receiving a first voice stream for a packet-switched call from a calling party, wherein the first voice stream conforms to a first silence suppression scheme and comprises a plurality of encoded packets for the packet-switched call; and forwarding the first voice stream toward a called party for the packet-switched call over a packet-switched network, wherein the packet-switched network is configured to receive voice streams which conform to a second silence suppression scheme, wherein the first silence suppression scheme is distinct from the second silence suppression scheme, wherein the plurality of encoded packets comprise at least one of: a synchronous packet, sent upon the first silence suppression interval according to the first silence suppression scheme, or an asynchronous packet, sent independently of the first silence suppression interval according to the first silence suppression scheme; wherein the second silence suppression scheme does not employ asynchronous packets; wherein the step of forwarding comprises the step of: forwarding one or more asynchronous packets of the first voice stream across the packet-switched network. ### Claim 15 (depends on 14) The method of claim 14, wherein the step of forwarding the one or more asynchronous packets comprises the step of: forwarding the one or more asynchronous packets independently of a silence suppression interval of the second silence suppression scheme.