PATENT DOCUMENT

Publication Number: US-8923796-B2
Application Number: US-201213358927-A
Country: US
Kind Code: B2

Title: Expedited call setup

Abstract:
An origination terminal initiates a call by providing a third party call control message in association with a traffic channel request. While the traffic channel is being established, the service node may initiate third party call control to initiate a call leg to the destination terminal on behalf of the origination terminal. As such, the destination call leg is initiated earlier. Since the destination call leg is initiated earlier, a corresponding ringback message indicating that a call is being presented to the called party is provided to the origination terminal sooner. When the ringback message is received quickly, a corresponding ringback indication may be presented to the caller in less time than was previously possible. The process is made even more efficient by waiting until the ringback message is received from the destination terminal before providing the SDP information, or communication information, for the origination terminal to the destination terminal.

Claims:
What is claimed is: 
     
       1. A method of operating a service node to provide an indication of ringing to an originating terminal initiating a call to a destination terminal via initiating a packet-based communication session, the method comprising:
 while a traffic channel is being requested by the originating terminal as part of initiating the call to the destination terminal, receiving, by the service node, instruction to initiate a call from the originating terminal to the destination terminal; 
 responsive to receiving the instruction, initiating, by the service node, third party call control, comprising initiating by the service node a destination call let to the destination terminal on behalf of the originating terminal; and 
 forwarding through the service node an indication of ringing from the destination terminal toward the originating terminal, in recognition that a packet-based communication session is being presented. 
 
     
     
       2. The method of  claim 1 , further comprising providing forwarding communication information for the originating terminal through the service node toward the destination terminal only after receiving the indication of ringing at the destination terminal. 
     
     
       3. The method of  claim 1 , wherein initiating, by the service node, the destination call leg to the destination terminal comprises establishing by the service node a destination signaling leg toward the destination terminal. 
     
     
       4. The method of  claim 3 , further comprising receiving, by the service node, the instruction comprises receiving by the service node a control message transmitted by the originating terminal requesting the traffic channel, wherein the control message identifies the originating terminal and the destination terminal; and
 establishing by the service node the destination signaling leg in response to receiving, by the service node, the control message. 
 
     
     
       5. The method of  claim 4 , further comprising establishing by the service node an origination signaling leg toward the originating terminal in response to receiving, by the service node, the control message. 
     
     
       6. The method of  claim 5 , wherein the control message provides no session data protocol information. 
     
     
       7. The method of  claim 5 , further comprising sending, by the service node an acceptance message toward the originating terminal via the origination signaling leg, wherein receiving, by the service node, the instruction comprises receiving, by the service node, a session initiation message from the originating terminal via the origination signaling leg. 
     
     
       8. The method of  claim 5 , wherein forwarding the indication of ringing through the service node toward the originating terminal comprises forwarding, by the service node, the indication of ringing on the origination signaling leg. 
     
     
       9. The method of  claim 1 , wherein the indication of ringing comprises destination communication parameters needed by the originating terminal to send packets toward the destination terminal. 
     
     
       10. The method of  claim 1 , comprising forwarding through the service node communication information for the originating terminal toward the destination terminal responsive to receiving the indication of ringing at the destination terminal. 
     
     
       11. The method of  claim 5  further comprising establishing, by the service node, the destination signaling leg and the origination signaling leg in parallel. 
     
     
       12. The method of  claim 1 , wherein the originating terminal is provided service via a radio access network. 
     
     
       13. The method of  claim 12 , wherein the radio access network is a cellular network. 
     
     
       14. The method of  claim 1 , wherein the traffic channel is requested by the originating terminal to support a packet-based communication session with the destination terminal. 
     
     
       15. The method of  claim 14 , wherein the packet-based communication session is a packet-based voice communication session. 
     
     
       16. The method of  claim 1 , further comprising:
 receiving the forwarded indication of ringing at the originating terminal; and 
 presenting a ringback indication from the originating terminal to a caller, responsive to receiving the forwarded indication of ringing at the originating terminal. 
 
     
     
       17. A service node comprising:
 one or more packet interfaces configured to facilitate communications over a packet-based communication network; and 
 a control system cooperating with the one or more packet interfaces to transmit and receive information, and configured to:
 receive instruction while a traffic channel is being requested by an originating terminal as part of the originating terminal initiating a call to a destination terminal via initiating a packet-based communication session, wherein the instruction is for the service node to initiate a call from the originating terminal to the destination terminal; 
 responsive to receiving the instruction, initiate third party call control by initiating a destination call let to the destination terminal on behalf of the originating terminal; and 
 receive an indication of ringing, provided in recognition that a packet-based communication session is being presented, from the destination terminal, and forward the indication of ringing toward the originating terminal. 
 
 
     
     
       18. The service node of  claim 17 , wherein the control system comprises:
 memory configured to store programming instructions executable by the control system to receive the instruction, initiate the third party call control, and receive and forward the indication of ringing. 
 
     
     
       19. A mobile terminal comprising:
 a radio frequency (RF) transmitter section configured to transmit RF signals; 
 an RF receiver section configured to receive RF signals; and 
 a control system cooperating with the RF transmitter section and the RF receive section to respectively transmit and receive information by way of RF signals, and configured to:
 initiate a call to a destination terminal by initiating a packet-based communication session; 
 request a traffic channel as part of initiating the call to the destination terminal; 
 send instruction to a service node while requesting the traffic channel, wherein the service node is configured to initiate third party call control responsive to the instruction by initiating a destination call leg to the destination terminal of behalf of the mobile terminal; and 
 receive an indication of ringing, wherein the indication of ringing is provided in recognition that a packet-based communication session is being presented, and is forwarded through the service node from the destination terminal. 
 
 
     
     
       20. The mobile terminal of  claim 19 , wherein the control system is further configured to provide basic communication control.

Description:
This application is a Continuation of co-pending U.S. patent application Ser. No. 11/615,468, entitled EXPEDITED CALL SETUP, filed Dec. 22, 2006, the disclosure of which is hereby incorporated by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to telecommunications, and in particular to expediting the time in which a caller receives a ringback indicator after initiating a call. 
     BACKGROUND OF THE INVENTION 
     Given the rapid acceptance of packet-based communications, various underlying communication infrastructures are evolving to support packet communications. In particular, cellular networks are evolving to support packet communications over existing wireless access technologies. Regardless of whether additional cellular communications or packet-based communications are supported, a signaling channel and a traffic channel are established between a mobile terminal and a radio access network, which supports communications with the mobile terminal. The signaling channel is a relatively low data rate communications channel that allows the mobile terminal to exchange signaling messages with the radio access network to establish and control communication sessions, which may be traditional cellular communications or packet-based communications. For a communication session, the traffic channel supports the bearer path and may be used to transmit voice information using traditional cellular or packet-based techniques. 
     For packet-based communications, the mobile terminal generally plays a greater role in call signaling, and in particular, for establishing and controlling packet-based communication sessions involving the mobile terminal. The call signaling messages exchanged with the mobile terminal over the radio access network are relatively longer and more involved than the traditional cellular-based signaling messages. Given the relatively low data rates provided by the radio access network for signaling channels, excessive delays may be incurred during the establishment of a packet-based communication session. 
     A particularly problematic issue arises when there is an extended delay between the time a caller initiates a call and receives a ringback indicator, which indicates that the called party&#39;s terminal is ringing. Currently, the delay between initiating a call and receiving a ringback indicator is much longer than the delay to which callers have grown accustomed. Impatient callers often mistake the extra delay as a malfunction, and prematurely end the call initiation attempt and immediately attempt to reinitiate the call. Such actions result in excessive use of radio access network resources, and the resultant delay frustrates callers. 
     Accordingly, there is a need for an effective and efficient way to provide a ringback indicator to a caller in response to initiating a packet-based communication session from a mobile terminal. 
     SUMMARY OF THE INVENTION 
     The present invention allows an origination terminal to initiate a call by providing a third party call control message in association with a traffic channel request. While the traffic channel is being established, the service node may initiate third party call control to initiate a call leg to the destination terminal on behalf of the origination terminal. As such, the destination call leg is initiated earlier in the process. Since the destination call leg is initiated earlier, a corresponding ringback message indicating that a call is being presented to the called party is provided to the origination terminal sooner. When the ringback message is received quickly, a corresponding ringback indication may be presented to the caller in much less time than was previously possible. The process is made even more efficient by waiting until the ringback message is received from the destination terminal before providing the SDP information, or communication information, for the origination terminal to the destination terminal. As such, the transfer of the relatively data-intensive communication information over the signaling paths of the origination and destination radio access networks takes place over faster traffic channels instead of slower signaling channels. 
     Those skilled in the art will appreciate the scope of the present invention and realize additional aspects thereof after reading the following detailed description of the preferred embodiments in association with the accompanying drawing figures. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The accompanying drawing figures incorporated in and forming a part of this specification illustrate several aspects of the invention, and together with the description serve to explain the principles of the invention. 
         FIG. 1  illustrates a communication environment according to one embodiment of the present invention. 
         FIGS. 2A and 2B  are a communication flow for establishing a packet-based communication session from a mobile terminal according to the prior art. 
         FIGS. 3A and 3B  are a communication flow for establishing a packet-based communication session from a mobile terminal according to one embodiment of the present invention. 
         FIG. 4  is a block representation of a service node according to one embodiment of the present invention. 
         FIG. 5  is a block representation of a mobile terminal according to one embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The embodiments set forth below represent the necessary information to enable those skilled in the art to practice the invention and illustrate the best mode of practicing the invention. Upon reading the following description in light of the accompanying drawing figures, those skilled in the art will understand the concepts of the invention and will recognize applications of these concepts not particularly addressed herein. It should be understood that these concepts and applications fall within the scope of the disclosure and the accompanying claims. 
     The present invention substantially reduces the time between a caller initiating a packet-based communication session and receiving a ringback indicator, which indicates that the session is being presented to a called party. The packet-based communication session may support a voice-based telephony call. The concepts of the present invention may be employed in any type of communication environment where a radio access network is coupled to a packet network to facilitate packet-based communications over a radio access channel provided by the radio access network. 
     Prior to delving into the details of the present invention, a communication environment is described in which packet-based communication sessions may be established over a radio access network and a packet network. Next, communication flows are presented to illustrate the difference between establishing a packet-based communication session according to the prior art and employing the present invention. In these examples, third party call control (3PCC) techniques are employed in a Third Generation Partnership Project version 2 (3GPP2) environment. As such, the invention may be employed in an Internet Protocol (IP) multimedia subsystem (IMS) that employs the Session Initiation Protocol (SIP) for session establishment and control. Those skilled in the art will recognize that the concepts of the present invention are applicable to other communication architectures using various communication protocols, without deviating from the teachings of the present invention. 
     With reference to  FIG. 1 , a communication environment  10  is provided including a packet network  12 , which interfaces directly or indirectly with any number of radio access networks  14 , such as an origination radio access network  14 O and a destination radio access network  14 D. Although the respective radio access networks  14  may support all originations and terminations, the “origination” and “destination” modifiers are presented to avoid confusion in the following communication flows. The origination radio access network  14 O is coupled to the packet network  12  over an appropriate origination edge node  16 O, which may represent any type of communication entity or gateway providing a transition point between the origination radio access network  14 O and the packet network  12 . Similarly, the destination radio access network  14 D is coupled to the packet network  12  by a destination edge node  16 D. The origination radio access network  14 O supports wireless communications with an origination terminal  18 O, and the destination radio access network  14 D supports wireless communications with a destination terminal  18 D. In these examples, a caller will originate a call from the origination terminal  18 O to a called party associated with the destination terminal  18 D. 
     A service node  20  is provided in the packet network  12  to act as a call or application manager. Call signaling may be exchanged between the origination and destination edge nodes  16 O and  16 D via the service node  20 . Call signaling between the origination edge node  16 O and the origination terminal  18 O as well as the destination edge node  16 D and destination terminal  18 D will ride on a signaling channel provided by the respective origination and destination radio access networks  14 O,  14 D. 
     Turning now to  FIGS. 2A and 2B , a communication flow for establishing a packet-based communication flow is provided according to the prior art. To initiate a call from the origination terminal (OT)  18 O to the destination terminal (DT)  18 D (step  100 ), the origination terminal  18 O may send a Request Traffic Channel (TCH) message over the origination radio access network  14 O to the origination edge node  16 O to request a traffic channel for the packet-based communication session (step  102 ). The origination edge node  16 O will allocate a traffic channel and send a Traffic Channel Granted message back to the origination terminal  18 O (step  104 ). Since the call being established is a packet-based communication session, the origination terminal  18 O will take the necessary steps to initiate the packet-based communication session with the destination terminal  18 D by sending a SIP Invite message toward the destination terminal  18 D. The Invite message is initially sent to the origination edge node  16 O (step  106 ), and will identify the origination terminal  18 O as the originating party and the destination terminal  18 D as the destination party. 
     The Invite message will also include the Session Data Protocol (SDP) for the origination terminal  18 O (SDP OT ), The SDP provides the requisite communication information to allow the destination terminal  18 D to communicate with the origination terminal  18 O. The SDP may include codec (coding/encoding) information, port information, encryption information, and the like. Notably, the Invite message, especially when it includes the SDP information for the origination terminal  18 O, is relatively large, and may reach or exceed 2 kilobytes (2 kb). As such, transferring the entire Invite message over the relatively low bandwidth signaling channel provided by the origination radio access network  14 O is time consuming and injects significant delay in the initiation process for the packet-based communication session. 
     The origination edge node  16 O will forward the Invite message received from the origination terminal  18 O to the service node  20  (step  108 ), which may further forward the Invite message toward the destination edge node  16 D that supports communications with the destination terminal  18 D (step  110 ). Upon receiving the Invite message intended for the destination terminal  18 D, the destination edge node  16 D will send a Page Request message toward the destination terminal  18 D (step  112 ). The destination terminal  18 D will recognize the Page Request as a need to establish communications with the destination edge node  16 D, and as such, may send a Page Response and a Request Traffic Channel message to the destination edge node  16 D (step  114 ). The destination edge node  16 D will allocate a traffic channel for the destination terminal  18 D and send a Traffic Channel Granted message to indicate the same back to the destination terminal  18 D (step  116 ). The destination edge node  16 D will then forward the Invite message to the destination terminal  18 D (step  118 ). Again, delivering the Invite message over the signaling channel to the destination terminal  18 D is relatively time consuming. 
     Upon receiving the Invite message, the destination terminal  18 D will recognize that a call is being presented from the origination terminal  18 O and will begin alerting the called party of the incoming packet-based communication session (or call) (step  120 ). The destination terminal  18 D will then provide a 180 Ringing message to the destination edge node  16 D to indicate that the packet-based communication session is being presented to the destination terminal  18 D, and that the called party is being alerted (step  122 ). The 180 Ringing message will provide the SDP information of the destination terminal  18 D (SDP DT ) to enable the origination terminal  18 O to communicate with the destination terminal  18 D. The 180 Ringing message will also indicate that it is a message for a packet-based communication session originated from the origination terminal  18 O, and intended for the destination terminal  18 D. 
     The destination edge node  16 D will send the 180 Ringing message to the service node  20  (step  124 ), which will forward the 180 Ringing message to the origination edge node  16 O (step  126 ). The origination edge node  16 O will then forward the 180 Ringing message to the origination terminal  18 O over the signaling channel provided by the origination radio access network  140  (step  128 ). Again, the 180 Ringing message will include the SDP information for the destination terminal  18 D, and as such, the 180 Ringing message will be significantly large, perhaps being as large if not larger than 1.5 kilobytes. These large messages take significant time to traverse the signaling channels provided by the respective origination and destination radio access networks  14 O,  14 D. Upon receiving the 180 Ringing message, the origination terminal  18 O will present a ringback indicator to them caller (step  130 ). As illustrated in FIG. 2B, a Provisional Acknowledgement (PR ACK) message is initially sent from the origination terminal  180  to the origination edge node  16 O (step  132 ), which forwards the PR ACK message to the service node  20 (step  134 ). From there, service node  20  forwards the PR ACK message toward the destination terminal  18 D via the destination edge node  16 D (steps  136  and  138 ). 
     For reference, the time between initiation of the call (step  100 ) and initially presenting the ringback indicator to the caller (step  130 ) is approximately 4200 ms (or 4.2 seconds). The time between initiating the call and presenting a ringback indicator to the caller for a traditional cellular call is generally 2 seconds or less. As such, incurring a delay of over 4 seconds between initiating a call and being presented with a ringback indicator triggers many callers to incorrectly conclude that there is a problem with the call they are initiating. Upon forming this errant conclusion, the caller may end the call initiation attempt and immediately reinitiate the call, only to be met with the same delay. 
     Assuming the caller has sufficient patience to allow the call to proceed, and the called party answers the packet-based communication session at the destination terminal  18 D (step  140 ), the destination terminal  18 D will send a 200 OK message to the destination edge node  16 D (step  142 ). The destination edge node  16 D will forward the 200 OK message to the service node  20  (step  144 ), which will forward the 200 OK message to the origination edge node  16 O (step  146 ). The origination edge node  16 O will forward the 200 OK message to the origination terminal  18 O (step  148 ), wherein the packet-based communication session may be established over an appropriate media path between the origination terminal  18 O and the destination terminal  18 D in traditional fashion (step  150 ). 
     The present invention employs third party call control (3PCC) technique to effectively initiate the packet-based communication session when the traffic channel is requested, as well as allow establishment of the origination and destination call legs to proceed in parallel. Such action significantly decreases the delay between initiating a packet-based communication session and receiving a ringback indicator, which indicates that a packet-based communication session is being presented to the called party. 
     Turning now to  FIGS. 3A and 3B , a communication flow is provided to illustrate operation of one embodiment of the present invention. In general, an initiation of a packet-based communication session from the origination terminal  18 O to the destination terminal  18 D will result in a third party call control message being sent to the service node  20  while a traffic channel is being requested by the origination terminal  18 O. The service node  20  will immediately begin establishing a destination call leg toward the destination terminal  18 D, as well as establish an origination call leg toward the origination terminal  18 O. The service node  20  will effectively connect the origination and destination call legs to enable the origination terminal  18 O and the destination terminal  18 D to exchange communication information, perhaps using SDP, such that a media path between the origination terminal  18 O and the destination terminal  18 D may be established for the packet-based communication session. A detailed communication flow is provided below. 
     The origination terminal  18 O will initiate a packet-based communication session (or call) to the destination terminal  18 D (step  200 ) by sending a Request Traffic Channel message and a (SIP) Refer message toward the origination edge node  16 O (step  202 ). The Refer message is a third party call control message that will ultimately instruct the service node  20  to initiate a call from the origination terminal  18 O to the destination terminal  18 D. The Refer message is intended for the service node  20 , and as such, it will indicate that the Refer message is from the origination terminal  18 O and intended for the service node (SN)  20 . The Refer message will also indicate that the service node  20  should refer the call to the destination terminal  18 D. Notably, there is no SDP provided in the Refer message, and as such, the Refer message may be compressed to a relatively small size. For example, the Refer message may be 200 bytes or less. The origination edge node  16 O will respond to the Refer message by sending the Refer message to the service node  20  (step  204 ), which will initiate third party call control and generate a token identifier (ID) for the origination call leg (step  206 ). 
     For third party call control, the service node  20  will send an Invite message to the destination edge node  16 D indicating that a call is being initiated from the origination terminal  18 O to the destination terminal  18 D (step  208 ). The Invite message will not include SDP information, but may identify the destination call leg with an appropriate call identifier (CALL ID 2). Upon receiving the Invite message, the destination edge node  16 D may send a Page Request to the destination terminal  18 D to indicate that a packet-based communication session is being presented (step  212 ). The destination terminal  18 D may respond with a Page Response as well as a Traffic Channel Request (step  214 ). The destination edge node  16 D will allocate a traffic channel in the destination radio access network  14 D for the destination terminal  18 D, and will send a Traffic Channel Granted message to the destination terminal  18 D (step  216 ). The destination edge node  16 D will then forward the Invite message to the destination terminal  18 D (step  218 ). The destination terminal  18 D will recognize that a packet-based communication session is being presented, and will begin alerting the called party (step  220 ). 
     While the destination call leg is being established, the service node  20  will complete the 3PCC transaction with the origination terminal  18 O by sending a (SIP) 202 Accepted message, or the like, to the origination edge node  16 O (step  220 ). The 202 Accepted message will indicate that a call is being established for the origination terminal  18 O to the destination terminal  18 D, and will provide the token ID for the origination leg as well as a call ID (CALL ID 1). Notably, each leg may be associated with different call IDs (CALL ID 1 and CALL ID 2). The service node  20  may modify the requisite call signaling to coordinate the respective origination and destination call legs. Further, the token ID will be returned by the origination terminal  18 O in a subsequent message to facilitate the service node  20  to correlate the messaging associated with the origination and destination call legs. 
     The origination edge node  16 O will respond to the initial Request Traffic Channel message by allocating a traffic channel in the origination radio access network  14 O for the packet-based communication session, and send a Traffic Channel Granted message to the origination terminal  18 O (step  222 ). In response to receiving the 202 Accepted message, the origination edge node  16 O will forward the 202 Accepted message to the origination terminal  18 O (step  224 ). Upon receiving the 202 Accepted message, the origination terminal  18 O is configured to respond by sending an Invite message to the service node  20  via the origination edge node  16 O (steps  226  and  228 ). The Invite message will provide the call ID (CALL ID 1) and the token ID to enable the service node  20  to correlate the Invite message with the packet-based communication session being established with the destination terminal  18 D. By doing so, the origination terminal is attempting to rendezvous with the call already in progress from the service node. The Invite message may not include the SDP for the origination terminal  18 O. As such, the Invite message will be relatively small, such as 1 kilobyte or less, and thus traverse the signaling channel between the origination terminal  18 O and the origination edge node  16 O relatively quickly. Upon receipt of the Invite message, the service node  20  will correlate the token ID provided in the Invite message with the destination call leg, and provide the requisite interworking between the origination and destination call legs (step  230 ), thus completing the rendezvous step initiated by the origination terminal. 
     Returning to the destination call leg, a 180 Ringing message is initiated by the destination terminal  18 D when alerting begins (step  232 ). The 180 Ringing message will identify the call ID (CALL ID 2) for the packet-based communication session, as well as the SDP information for the destination terminal  18 D (SDP DT ). Notably, this is the first offering of SDP information among the origination and destination terminals  18 O and  18 D. The 180 Ringing message will also indicate that the packet-based communication session is being originated from the origination terminal  18 O and terminated at the destination terminal  18 D. 
     The destination edge node  16 D will receive the 180 Ringing message from the destination terminal  18 D and forward the 180 Ringing message toward the service node  20  (step  234 ). The 180 Ringing message may be approximately 1 kilobyte in size. The service node  20  will provide the requisite interworking between the destination and origination call legs by changing the call ID (CALL ID 2 to CALL ID 1) and modify any other information as necessary to facilitate a fluid communication message exchange between the origination terminal  18 O and the destination terminal  18 D. As such, the modified 180 Ringing message is forwarded toward the origination terminal  18 O via the origination edge node  16 O (steps  236  and  238 ). The origination terminal  18 O will receive the 180 Ringing message and the included SDP information for the destination terminal  18 D and present a ring back indicator to the caller(step  240 ). 
     In this example, the ringback indicator is presented to the caller within 1900 ms (1.9 seconds) from the time the caller initiated the packet-based communication session. By comparison with the communication flow of  FIGS. 2A and 2B , the ringback indicator is presented to the caller in less than half the time required in the prior art. 
     Since the origination terminal  18 O has not provided its SDP information to the destination terminal  18 D, the SDP information of the origination terminal  18 O (SDP OT ) may be provided to the destination terminal  18 D in a Provisional Acknowledgement (PR ACK) message. As illustrated, the PR ACK is initially sent from the origination terminal  18 O to the origination edge node  16 O (step  242 ), which forwards the PR ACK to the service node  20  (step  244 ). The service node  20  will modify any information in the PR ACK message, such as the call ID (CALL ID 1 to CALL ID 2), and forward the message toward the destination terminal  18 D via the destination edge node  16 D (steps  246  and  248 ). At this point, the destination terminal  18 D has the SDP information for the origination terminal  18 O. Since the origination and destination terminals  18 O and  18 D have each other&#39;s SDP information, they can effectively communicate with each other. 
     When the destination terminal  18 D is answered by the called party (step  250 ), the destination terminal  18 D may send a 200 OK message toward the origination terminal  18 O. The 200 OK message is forwarded through the destination edge node  16 O (step  252 ), service node  20  (step  254 ), and origination edge node  16 O (step  256 ) en route to the origination terminal  18 O (step  258 ). At this point, a media path is established between the origination terminal  18 O and the destination terminal  18 D for the packet-based communication session (step  260 ). 
     As seen from the above, the present invention allows an origination terminal  18 O to initiate a call by providing a third party call control message in association with a traffic channel request. While the traffic channel is being established, the service node  20  may initiate third party call control to initiate call legs to the origination terminal  18 O and the destination terminal  18 D. As such, the destination call leg is initiated earlier in the process. Since the destination call leg is initiated earlier, a corresponding ringback message indicating that a call is being presented to the called party is provided to the origination terminal  18 O sooner. When the ringback message is received quickly, a corresponding ringback indication may be presented to the caller in much less time than was previously possible. The process is made even more efficient by waiting until the ringback message is received from the destination terminal  18 D before providing the SDP information, or communication information, for the origination terminal  18 O to the destination terminal  18 D. As such, the transfer of the relatively data-intensive communication information over the traffic channel signaling paths of the origination and destination radio access networks  14 O,  14 D does not delay presentation of a call to the destination terminal  18 D and receipt of a ringback message at the origination terminal  18 O. 
     A block representation of a service node  20  is provided in  FIG. 4 . The service node  20  will include a control system  22  having sufficient memory  24  for the requisite software  26  and data  28  to operate as described above. The control system  22  will be associated with one or more packet interfaces  30  to facilitate communications with various entities over the packet network  12 . 
     The basic architecture of a mobile terminal  18 , such as the origination or destination terminals  18 O and  18 D, is provided in  FIG. 5 . The mobile terminal  18  may include a receiver front end  32 , a radio frequency transmitter section  34 , an antenna  36 , a duplexer or switch  38 , a baseband processor  40 , a control system  42 , a frequency synthesizer  44 , and a user interface  46 . The receiver front end  32  receives radio frequency signals from one or more remote transmitters provided by a base station in a radio access network  14 . A low noise amplifier (LNA)  48  amplifies the signals. A filter circuit  50  minimizes broadband interference in the received signals, while downconversion and digitization circuitry  52  downconverts the filtered, received signals to intermediate or baseband frequency signals, which are then digitized into one or more digital streams. The receiver front end  32  typically uses one or more mixing frequencies generated by the frequency synthesizer  44  to downconvert the received signals the intermediate or baseband signals. The baseband processor  40  processes the digitized streams to extract the information or data bits conveyed in the received signal. This processing typically comprises demodulation, decoding, and error correction operations. As such, the baseband processor  40  is generally implemented in one or more digital signal processors (DSPs). 
     On the transmit side, the baseband processor  40  receives digitized data, which may represent voice, data, or control information, from the control system  42 , which it encodes for transmission. The encoded data is output to the transmitter  34 , where it is used by a modulator  54  to modulate a carrier signal having a desired transmit frequency. Power amplifier circuitry  56  amplifies the modulated carrier signal to a level appropriate for transmission, and delivers the amplified and modulated carrier signal to the antenna  36  through the duplexer or switch  38 . In addition to providing basic communication control, the control system  42  and other components of the mobile terminal cooperate to provide the functionality of by the present invention, as described above. 
     A user may interact with the mobile terminal via the interface  46 , which may include interface circuitry  58  associated with a microphone  60 , a speaker  62 , a keypad  64 , and a display  66 . The interface circuitry  58  typically includes analog-to-digital converters, digital-to-analog converters, amplifiers, and the like. Additionally, it may include a voice encoder/decoder, in which case it may communicate directly with the baseband processor  40 . The microphone  60  will typically convert audio input, such as the user&#39;s voice, into an electrical signal, which is then digitized and passed directly or indirectly to the baseband processor  40 . Audio information encoded in the received signal is recovered by the baseband processor  40 , and converted by the interface circuitry  58  into an analog signal suitable for driving the speaker  62 . The keypad  64  and display  66  enable the user to interact with the mobile terminal, input numbers to be dialed, address book information, or the like, as well as monitor call progress information. 
     Those skilled in the art will recognize improvements and modifications to the preferred embodiments of the present invention. All such improvements and modifications are considered within the scope of the concepts disclosed herein and the claims that follow.

Metadata:
Filing Date: 20120126
Publication Date: 20141230
Grant Date: 20141230
Priority Date: 20061222
Inventors: STUCKER BRIAN
Assignee: APPLE INC
CPC Classifications: [{"code": "H04M3/42195", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/57", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L12/66", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L65/1069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L12/66", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L12/66", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L65/1069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/57", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/57", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M3/42195", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M3/42195", "inventive": true, "first": false, "tree": "[]"}]
Family ID: 45572057