Advanced LMSD intersystem handoff
First Claim
1. An Anchor Mobile Switching Center emulation (MSCe) for supporting an intersystem handoff of a Mobile Station (MS) from an Anchor Network to a Target Network, wherein the MS is in communication with a B-Party, wherein the Anchor Network comprises an Anchor Base Station (BS), the Anchor MSCe and an Anchor Media Gateway (MGW), and wherein the Target Network comprises a Target BS, a Target MSCe and a Target MGW, the Anchor MSCe comprising:
- a Target MSCe message interface configured to send a Handoff Request message to the Target MSCe, wherein the Handoff Request message comprises a Session Initiation Protocol (SIP) INVITE message that contains a TIA/EIA-41 FacilitiesDirective2 INVOKE message;
the Target MSCe message interface is further configured to receive from the Target MSCe a SIP Provisional Response which contains a TIA/EIA-41 FacilitiesDirective2 RETURN RESULT message;
the Target MSCe message interface is further configured to receive from the Target MSCe a SIP 200 OK (INVITE) message indicating that the MS has established a connection with the Target BS, wherein the SIP 200 OK (INVITE) message is received after receipt of the SIP Provisional Response;
the Anchor MSCe is configured to evaluate whether the Anchor MGW supports transcoding between a first codec established for a first termination to the B-Party and a second codec established for a second termination to the Target MGW which will result in a voice bearer that meets or exceeds a pre-established criteria;
based on a positive evaluation, the Anchor MSCe instructs the Anchor MGW to connect the first termination to the second termination; and
based on a negative evaluation, the Anchor MSCe solicits a Session Description Protocol (SDP) offer/answer exchange between the B-Party and the Target MGW to establish a codec combination for a voice bearer path between the B-Party and the MS that meets or exceeds the pre-established criteria.
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Accused Products
Abstract
An Anchor Mobile Switching Center emulation (MSCe) and a Target MSCe are described herein that take part in an intersystem handoff of a Mobile Station (MS) which is in communication with a B-party. Upon the MS establishing a connection with the Target MSCe, the Anchor MSCe may perform SDP offer/answer exchange between the Target network and the B-Party for the purpose of codec renegotiation to correct a transcoding incompatibility or to enhance the voice bearer path characteristics or to minimize the number of transcodings in the bearer path, between the two parties. The Anchor MSCe and the Target MSCe both support Advanced Legacy Mobile Station Domain (ALMSD) implying that only the SIP transport is used for intersystem handoff communications.
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Citations
20 Claims
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1. An Anchor Mobile Switching Center emulation (MSCe) for supporting an intersystem handoff of a Mobile Station (MS) from an Anchor Network to a Target Network, wherein the MS is in communication with a B-Party, wherein the Anchor Network comprises an Anchor Base Station (BS), the Anchor MSCe and an Anchor Media Gateway (MGW), and wherein the Target Network comprises a Target BS, a Target MSCe and a Target MGW, the Anchor MSCe comprising:
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a Target MSCe message interface configured to send a Handoff Request message to the Target MSCe, wherein the Handoff Request message comprises a Session Initiation Protocol (SIP) INVITE message that contains a TIA/EIA-41 FacilitiesDirective2 INVOKE message; the Target MSCe message interface is further configured to receive from the Target MSCe a SIP Provisional Response which contains a TIA/EIA-41 FacilitiesDirective2 RETURN RESULT message; the Target MSCe message interface is further configured to receive from the Target MSCe a SIP 200 OK (INVITE) message indicating that the MS has established a connection with the Target BS, wherein the SIP 200 OK (INVITE) message is received after receipt of the SIP Provisional Response; the Anchor MSCe is configured to evaluate whether the Anchor MGW supports transcoding between a first codec established for a first termination to the B-Party and a second codec established for a second termination to the Target MGW which will result in a voice bearer that meets or exceeds a pre-established criteria; based on a positive evaluation, the Anchor MSCe instructs the Anchor MGW to connect the first termination to the second termination; and based on a negative evaluation, the Anchor MSCe solicits a Session Description Protocol (SDP) offer/answer exchange between the B-Party and the Target MGW to establish a codec combination for a voice bearer path between the B-Party and the MS that meets or exceeds the pre-established criteria. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A method implemented by an Anchor Mobile Switching Center emulation (MSCe) for supporting an intersystem handoff of a Mobile Station (MS) from an Anchor Network to a Target Network, wherein the MS is in communication with a B-Party, wherein the Anchor Network comprises an Anchor Base Station (BS), the Anchor MSCe and an Anchor Media Gateway (MGW), and wherein the Target Network comprises a Target BS, a Target MSCe and a Target MGW, the method comprising the steps of:
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sending a Handoff Request message to the Target MSCe, wherein the Handoff Request message comprises a Session Initiation Protocol (SIP) INVITE message that contains a TIA/EIA-41 FacilitiesDirective2 INVOKE message; receiving from the Target MSCe a SIP Provisional Response which contains a TIA/EIA-41 FacilitiesDirective2 RETURN RESULT message; receiving from the Target MSCe a SIP 200 OK (INVITE) message indicating that the MS has established a connection with the Target BS, wherein the SIP 200 OK (INVITE) message is received after receipt of the SIP Provisional Response; evaluating whether the Anchor MGW supports transcoding between a first codec established for a first termination to the B-Party and a second codec established for a second termination to the Target MGW which will result in a voice bearer that meets or exceeds a pre-established criteria; based on a positive evaluation, instructing the Anchor MGW to connect the first termination to the second termination; and based on a negative evaluation, soliciting a Session Description Protocol (SDP) offer/answer exchange between the B-Party and the Target MGW to establish a codec combination for a voice bearer path between the B-Party and the MS that meets or exceeds the pre-established criteria. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A Target Mobile Switching Center emulation (MSCe) for supporting an intersystem handoff of a Mobile Station (MS) from an Anchor Network to a Target Network, wherein the MS is in communication with a B-Party, wherein the Anchor Network comprises an Anchor Base Station (BS), an Anchor MSCe and an Anchor Media Gateway (MGW), and wherein the Target Network comprises a Target BS, the Target MSCe and a Target MGW, the Target MSCEe comprising:
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an Anchor MSCe message interface configured to receive a Handoff Request message from the Anchor MSCe, wherein the Handoff Request message comprises a Session Initiation Protocol (SIP) INVITE message that contains a TIA/EIA-41 FacilitiesDirective2 INVOKE message; the Anchor MSCe message interface is further configured to send to the Anchor MSCe a SIP Provisional Response which contains a TIA/EIA-41 FacilitiesDirective2 RETURN RESULT message; the Target MSCe is configured to establish bearer resources in the Target MGW and the Target BS; the Anchor MSCe message interface is further configured to send to the Anchor MSCe a SIP 200 OK (INVITE) message indicating that the MS has established a connection with the Target BS, wherein the SIP 200 OK (INVITE) message is sent after the SIP Provisional Response is sent the Target MSCe is further configured to; receive a SIP re-INVITE from the Anchor MSCe where the SIP re-INVITE contains an SDP offer; send a command to the Target MGW to modify a first termination to the Anchor MGW based on a codec list in the SDP offer; receive a reply from the Target MGW where the reply contains a local SDP including a list of codecs that are in common with codecs in the codec list in the SDP offer and a list of codecs for which the Target MGW can transcode based on the codec list in the SDP offer; and send a reliable non-failure SIP response message to the Anchor MSCe where the reliable non-failure SIP response message contains a SDP answer to the SDP offer. - View Dependent Claims (16, 17)
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18. A method implemented by a Target Mobile Switching Center emulation (MSCe) for supporting an intersystem handoff of a Mobile Station (MS) from an Anchor Network to a Target Network, wherein the MS is in communication with a B-Party, wherein the Anchor Network comprises an Anchor Base Station (BS), an Anchor MSCe and an Anchor Media Gateway (MGW), and wherein the Target Network comprises a Target BS, the Target MSCe and a Target MGW, the method comprising the steps of:
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receiving a Handoff Request message from the Anchor MSCe, wherein the Handoff Request message comprises a Session Initiation Protocol (SIP) INVITE message that contains a TIA/EIA-41 FacilitiesDirective2 INVOKE message; sending to the Anchor MSCe a SIP Provisional Response which contains a TIA/EIA-41 FacilitiesDirective2 RETURN RESULT message; establishing bearer resources in the Target MGW and the Target BS; sending to the Anchor MSCe a SIP 200 OK (INVITE) message indicating that the MS has established a connection with the Target BS, wherein the SIP 200 OK (INVITE) message is sent after the SIP Provisional Response is sent; receiving a SIP re-INVITE from the Anchor MSCe where the SIP re-INVITE contains an SDP offer; and sending a command to the Target MGW to modify a first termination to the Anchor MGW based on a codec list in the SDP offer; receiving a reply from the Target MGW where the reply contains a local SDP including a list of codecs that are in common with codecs in the codec list in the SDP offer and a list of codecs for which the Target MGW can transcode based on the codec list in the SDP offer; and sending a reliable non-failure SIP response message to the Anchor MSCe where the reliable non-failure SIP response message contains a SDP answer to the SDP offer. - View Dependent Claims (19, 20)
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Specification