PATENT DOCUMENT

Publication Number: US-10966260-B2
Application Number: US-201515755360-A
Country: US
Kind Code: B2

Title: Device, system and method for VoLTE setup

Abstract:
A device, system, and method performs a Voice over Long Term Evolution (LTE) (VoLTE) call setup procedure. The device includes a transceiver establishing a connection with a LTE network and an Internet Protocol (IP) Multimedia Subsystem (IMS). The device includes a processor executing a VoLTE call application with a further user equipment, receiving an input to execute the VoLTE call application, and generating a data packet including an indication to trigger a dedicated bearer establishment procedure. The transceiver transmits the data packet to one of the LTE network and the IMS. The indication triggers the dedicated bearer establishment procedure to be performed during a Session Initiation Protocol (SIP) signal exchange procedure.

Claims:
What is claimed is: 
     
       1. A user equipment, comprising:
 a transceiver configured to establish a connection with a Long Term Evolution (LTE) Network and an Internet Protocol (IP) Multimedia Subsystem (IMS); and 
 a processor configured to execute a Voice over LTE (VoLTE) call application with a further user equipment, the processor configured to receive an input to execute the VoLTE call application, the processor configured to generate a data packet including an indication to trigger a dedicated bearer establishment procedure, 
 wherein the transceiver is configured to transmit the data packet to one of the LTE network and the IMS, 
 wherein the indication triggers the dedicated bearer establishment procedure to be performed during a Session Initiation Protocol (SIP) signal exchange procedure. 
 
     
     
       2. The user equipment of  claim 1 , wherein the transceiver initially connects to the LTE network, subsequently connects to the IMS, and registers with the IMS. 
     
     
       3. The user equipment of  claim 1 , wherein the packet data is included in a radio resource control (RRC) procedure with the LTE network. 
     
     
       4. The user equipment of  claim 3 , wherein the packet data includes a special cause identification to indicate to the LTE network to reserve a Quality of Service (QOS) Class Identifier (QCI) 1 resource. 
     
     
       5. The user equipment of  claim 1 , wherein the data packet is included in an uplink (UL) information transfer with a mobility management entity (MME) of the IMS. 
     
     
       6. The user equipment of  claim 5 , wherein the UL information transfer triggers a QCI1 establishment procedure at a Packet Data Network (PDN) Gateway (PGW) of the IMS. 
     
     
       7. The user equipment of  claim 1 , wherein the packet data is included in a service request (SR) with the LTE network. 
     
     
       8. The user equipment of  claim 1 , wherein the packet data includes a security header to reserve a QCI1 resource. 
     
     
       9. A method comprising:
 at a user equipment (UE) configured to perform a Voice over Long Term Evolution (LTE) (VoLTE) call with a further UE, the UE connected to a LTE network and an Internet Protocol (IP) Multimedia Subsystem (IMS):
 receiving an input to execute a VoLTE call application; 
 generating a data packet including an indication to trigger a dedicated bearer establishment procedure; and 
 transmitting the data packet to one of the LTE network and the IMS, 
 wherein the indication triggers the dedicated bearer establishment procedure to be performed during Session Indication Protocol (SIP) signal exchange procedure. 
 
 
     
     
       10. The method of  claim 9 , further comprising:
 initially connecting to the LTE network; 
 connecting to the IMS; and 
 registering with the IMS. 
 
     
     
       11. The method of  claim 9 , wherein the data packet is included in a radio resource control (RRC) procedure with the LTE network. 
     
     
       12. The method of  claim 11 , wherein the data packet includes a special cause identification to indicate to the LTE network to reserve a Quality of Service (QOS) Class Identifier (QCI) 1 resource. 
     
     
       13. The method of  claim 9 , wherein the data packet is included in an uplink (UL) information transfer with a mobility management entity (MME) of the IMS. 
     
     
       14. The method of  claim 13 , wherein the UL information transfer triggers a QCI1 establishment procedure at a Packet Data Network (PDN) Gateway (PGW) of the IMS. 
     
     
       15. The method of  claim 9 , wherein the data packet is included in service request (SR) with the LTE network. 
     
     
       16. The method of  claim 15 , wherein the data packet is includes a security header to reserve a QCI1 resource. 
     
     
       17. A network component of an Internet Protocol (IP) Multimedia Subsystem (IMS), the network component comprising:
 a transceiver configured to establish a connection with a Long Term Evolution (LTE) Network and first and second user equipments configured to perform a Voice over LTE (VoLTE) call; and 
 a processor configured to receive a Session Initiation Protocol (SIP) invite from the first user equipment to perform the VoLTE call with the second user equipment, the processor configured to generate a data packet to trigger a dedicated bearer establishment procedure, the processor configured to perform a forwarding operation to transmit the SIP invite to the second user equipment and to transmit the data packet to a gateway of the IMS, 
 wherein the data packet enables the dedicated bearer to be established during further SIP signal exchanges. 
 
     
     
       18. The network component of  claim 17 , wherein the network component is a proxy-call session control function (P-CSCF) component. 
     
     
       19. A method, comprising:
 at a network component of an Internet Protocol (IP) Multimedia Subsystem (IMS),
 establishing a connection with a Long Term Evolution (LTE) Network and first and second user equipments configured to perform a Voice over LTE (VoLTE) call; 
 receiving a Session Initiation Protocol (SIP) invite from the first user equipment to perform the VoLTE call with the second user equipment; 
 generating a data packet to trigger a dedicated bearer establishment procedure; and 
 performing a forwarding operation to transmit the SIP invite to the second user equipment and to transmit the data packet to a gateway of the IMS, 
 wherein the data packet enables the dedicated bearer to be established during further SIP signal exchanges. 
 
 
     
     
       20. The method of  claim 19 , wherein the network component is a proxy-call session control function (P-CSCF) component.

Description:
BACKGROUND INFORMATION 
     A first station may be configured to communicate wirelessly with a second station. Specifically, the first station may transmit data to and receive data from the second station through a wired or wireless communications network. The first and second stations may use the network to communicate using a variety of different applications. For example, the first station may be a mobile originating (MO) user equipment (UE) while the second station may be a mobile terminating (MT) UE for a voice call. The voice call may be performed in a variety of different manners. For example, when the MO or MT UE is connected to a legacy network, the voice call may be performed using circuit switching. In another example, when the MO or MT UE is connected to an Internet Protocol (IP) data transmission network, the voice call may be performed using Voice over IP (VoIP). More specifically, when the network is a Long Term Evolution (LTE) network, the VoIP call may be a Voice over LTE (VoLTE) call. 
     When the VoLTE call is performed, the MO and MT UEs may perform a setup procedure. Initially, when the MO and MT UEs connect to the LTE network, each UE may be associated with one or more default bearers that provide a best effort service in the exchange of data with the LTE network. Furthermore, when a particular application is being utilized such as the VoLTE call, each UE may be associated with a dedicated bearer that provides a dedicated tunnel for data to be transmitted with regard to the VoLTE call (e.g., the voice data). The dedicated bearer may provide a variety of functionalities such as improving throughput or guaranteeing a bit rate for the data to be transmitted. The setup procedure utilizes various operations that are performed. However, due to an ordering of the operations, a timing of the operations, an execution of the operations, etc., a user experience may be negatively impacted such as delays being introduced. 
     SUMMARY 
     A first exemplary embodiment is directed to a user equipment comprising: a transceiver configured to establish a connection with a Long Term Evolution (LTE) Network and an Internet Protocol (IP) Multimedia Subsystem (IMS); and a processor configured to execute a Voice over LTE (VoLTE) call application with a further user equipment, the processor configured to receive an input to execute the VoLTE call application, the processor configured to generate a data packet including an indication to trigger a dedicated bearer establishment procedure, wherein the transceiver is configured to transmit the data packet to one of the LTE network and the IMS, wherein the indication triggers the dedicated bearer establishment procedure to be performed during a Session Initiation Protocol (SIP) signal exchange procedure. 
     Another exemplary embodiment is directed to A method comprising at a UE configured to perform a VoLTE call with a further UE, the UE connected to a LTE network and an IMS: receiving an input to execute a VoLTE call application; generating a data packet including an indication to trigger a dedicated bearer establishment procedure; and transmitting the data packet to one of the LTE network and the IMS, wherein the indication triggers the dedicated bearer establishment procedure to be performed during a SIP signal exchange procedure. 
     A further exemplary embodiment is directed to a network component of an IMS, the network component comprising a transceiver configured to establish a connection with a LTE Network and first and second user equipments configured to perform a VoLTE call; and a processor configured to receive a SIP invite from the first user equipment to perform the VoLTE call with the second user equipment, the processor configured to generate a data packet to trigger a dedicated bearer establishment procedure, the processor configured to perform a forwarding operation to transmit the SIP invite to the second user equipment and to transmit the data packet to a gateway of the IMS, wherein the data packet enables the dedicated bearer to be established during further SIP signal exchanges. 
     A yet further exemplary embodiment is directed to a method comprising: at a network component of an IMS, establishing a connection with a LTE Network and first and second user equipments configured to perform a VoLTE call; receiving a SIP invite from the first user equipment to perform the VoLTE call with the second user equipment; generating a data packet to trigger a dedicated bearer establishment procedure; and performing a forwarding operation to transmit the SIP invite to the second user equipment and to transmit the data packet to a gateway of the IMS, wherein the data packet enables the dedicated bearer to be established during further SIP signal exchanges. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows an exemplary network arrangement, according to some embodiments. 
         FIG. 2  shows an exemplary user equipment configured to establish a dedicated bearer, according to some embodiments. 
         FIG. 3  shows a first exemplary signaling diagram for establishing a dedicated bearer through a user equipment operation, according to some embodiments. 
         FIG. 4  shows a second exemplary signaling diagram for establishing a dedicated bearer through a user equipment operation, according to some embodiments. 
         FIG. 5  shows a third exemplary signaling diagram for establishing a dedicated bearer through a user equipment operation, according to some embodiments. 
         FIG. 6  shows an exemplary method for establishing a dedicated bearer through a user equipment operation, according to some embodiments. 
         FIG. 7  shows an exemplary signaling diagram for establishing a dedicated bearer through a network operation, according to some embodiments. 
         FIG. 8  shows an exemplary method for establishing a dedicated bearer through a network operation, according to some embodiments. 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary embodiments may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary embodiments are related to a device, system, and method for establishing a dedicated bearer for a Voice over Long Term Evolution (LTE) (VoLTE) call. Specifically, the exemplary embodiments provide a mechanism by which the dedicated bearer may be established or prepared to be established to remove a delay when performing a setup procedure for the VoLTE call. In a first exemplary embodiment, a mobile originating (MO) user equipment (UE) may perform an operation to prepare the dedicated bearer to be established. In a second exemplary embodiment, a network component may perform an operation to establish the dedicated bearer based upon an early trigger. 
     Initially, it is noted that the exemplary embodiments are described with regard to a VoLTE call. However, the VoLTE call is only exemplary. In some exemplary embodiments, the VoLTE may be a component of the communication performed by the MO UE. For example, the VoLTE may be a component of a video over LTE functionality. Thus, any use of a VoLTE call or a voice call may be representative of other communication calls including a video call. 
       FIG. 1  shows an exemplary network arrangement  100 , according to some embodiments. The exemplary network arrangement  100  includes UEs  110 - 114 . In this example, it is assumed that a respective, different user is using each of the UEs  100 - 114 . For example, a first user may be utilizing the UE  110 , a second user may be utilizing the UE  112 , and a third user may be utilizing the UE  114 . Those skilled in the art will understand that the UEs  110 - 114  may be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, desktop computers, smartphones, phablets, embedded devices, wearables, etc. It should also be understood that an actual network arrangement may include any number of UEs being used by any number of users and being associated with any number of these users where the user may be associated with one or more of the UEs. That is, the example of three (3) UEs  110 - 114  is only provided for illustrative purposes. However, as will be understood from the description herein, the exemplary embodiments may relate to when at least two UEs  110 - 114  are present in the network arrangement  100 . 
     Each of the UEs  110 - 114  may be configured to communicate with one or more networks. In this example, the networks with which the UEs  110 - 114  may communicate are a legacy radio access network (RAN)  120 , a LTE RAN (LTE-RAN)  122 , and a wireless local area network (WLAN)  124 . In this example, each of the networks  120 - 124  is a wireless network with which the UEs  110 - 114  may communicate wirelessly. However, it should be understood that the UEs  110 - 114  may also communicate with other types of networks using a wired connection. With regards to the exemplary embodiments, the UEs  110 - 114  may establish a connection with the LTE-RAN  122  to perform VoLTE calls with other UEs. For example, the UEs  110 - 114  may have a LTE chipset to communicate with the LTE-RAN  122 . Again, the use of three (3) networks is only exemplary and there may be any other number of networks with which the UEs  110 - 114  may communicate. 
     The legacy RAN  120  and the LTE-RAN  122  are portions of cellular networks that may be deployed by cellular providers (e.g., Verizon, AT&amp;T, Sprint, T-Mobile, etc.). These networks  120  and  122  may include, for example, base stations (Node Bs, eNodeBs, HeNBs, etc.) that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. Examples of the legacy RAN  120  may include those networks that are generally labeled as 2G and/or 3G networks and may include circuit switched voice calls and packet switched data operations. Those skilled in the art will understand that the cellular providers may also deploy other types of networks, including further evolutions of the cellular standards, within their cellular networks. The WLAN  124  may include any type of wireless local area network (WiFi, Hot Spot, IEEE 802.11x networks, etc.). Those skilled in the art will understand that there may be thousands, hundreds of thousands or more of different WLANs deployed in the United States alone. For example, the WLAN  124  may be the user&#39;s home network, the user&#39;s work network, a public network (e.g., at a city park, coffee shop, etc.). Generally, the WLAN  124  will include one or more access points that allow the UEs  110 - 114  to communicate with the WLAN  124 . However, as noted above, the exemplary embodiments relate to the UEs  110 - 114  utilizing the LTE-RAN  122  to perform VoLTE calls. 
     In addition to the networks  120 - 124 , the network arrangement  100  also includes a cellular core network  130  and the Internet  140 . The cellular core network  130 , the legacy RAN  120 , and the LTE-RAN  122  may be considered a cellular network that is associated with a particular cellular provider (e.g., Verizon, AT&amp;T, Sprint, T-Mobile, etc.). The cellular core network  130  may be considered to be the interconnected set of components that manages the operation and traffic of the cellular network. The interconnected components of the cellular core network  130  may include any number of components such as servers, switches, routers, etc. The cellular core network  130  also manages the traffic that flows between the cellular network and the Internet  140 . 
     The network arrangement  100  also includes an IP Multimedia Subsystem (IMS)  150 . The IMS  150  may be generally described as an architecture for delivering multimedia services to the UEs  110 - 114  using the IP protocol. The IMS  150  may include a variety of components to accomplish this task. For example, a typical IMS  150  includes a Home Subscriber Server (HSS) that stores subscription information for a user of the UEs  110 - 114 . Thus, when the corresponding UE of the user registers with the IMS  150  (e.g., connects thereto), the subscription information may be utilized to determine various features. For example, this subscription information is used to provide the correct multimedia services to the user such as a VoLTE call. The IMS  150  may communicate with the cellular core network  130  and the Internet  140  to provide the multimedia services to the UEs  110 - 114 . The IMS  150  is shown in close proximity to the cellular core network  130  because the cellular provider typically implements the functionality of the IMS  150 . However, it is not necessary for this to be the case such as when the IMS  150  is provided by another party. 
     Thus, the network arrangement  100  allows the UEs  110 - 114  to perform functionalities generally associated with computers and cellular networks. For example, the UEs  110 - 114  may perform the VoLTE calls to other parties, may browse the Internet  140  for information, may stream multimedia data to the UEs  110 - 114 , etc. 
     The network arrangement  100  may also include a network services backbone  160  that is in communication either directly or indirectly with the Internet  140  and the cellular core network  130 . The network services backbone  160  may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UEs  110 - 114  in communication with the various networks. The network services backbone  160  may interact with the UEs  110 - 114  and/or the networks  120 ,  122 ,  124 ,  130 ,  140  to provide these extended functionalities. 
     The network services backbone  160  may be provided by any entity or a set of entities. In one example, the network services backbone  160  is provided by the supplier of one or more of the UEs  110 - 114 . In another example, the network services backbone  160  is provided by the cellular network provider. In still a further example, the network services backbone  160  is provided by a third party unrelated to the cellular network provider or the supplier of the UEs  110 - 114 . 
     The exemplary embodiments relate to the UEs  110 - 114  performing a VoLTE call. For example, the UE  110  may be the MO UE that invites a further UE such as the UE  112 , which may be a mobile terminating (MT) UE. Initially, the UEs  110 - 114  establish a connection to the LTE-RAN  122 . Those skilled in the art will understand that any association procedure may be performed for the UEs  110 - 114  to connect to the LTE-RAN  122 . For example, as discussed above, the LTE-RAN  122  may be associated with a particular cellular provider where the UE  110 - 114  and/or the user thereof has a contract and credential information (e.g., stored on a SIM card). Upon detecting the presence of the LTE-RAN  122 , the UEs  110 - 114  may transmit the corresponding credential information to associate with the LTE-RAN  122 . More specifically, the UEs  110 - 114  may associate with a specific base station (e.g., an eNB of the LTE-RAN  122 ). 
     When the UEs  110 - 114  associate and establish a connection with the LTE-RAN  122 , one or more default bearers may be established for the UE  110 - 114 . Initially, a bearer may define how data is treated when transmitted through the network. That is, the bearer may be a set of network parameters that define data specific treatment by type or association with an application. Accordingly, the LTE-RAN  122  may treat a first type of data in a first way and treat a second type of data in a second way. For example, the first type of data may be prioritized so that the LTE-RAN  122  treats this data in a special manner. It should be noted that the bearer may also define the treatment based upon user identity or other identification parameters. 
     One type of bearer that is established when initially connecting to the LTE-RAN  122  is a default bearer. The LTE-RAN  122  via the associated eNB may assign the default bearer, which remains so long as the UE is connected to the LTE-RAN  122 . The default bearer may be a best effort service for the data transmitted through the LTE-RAN  122 . Thus, depending upon various network conditions currently being experienced by the LTE-RAN  122 , the data being transmitted through the default bearer may be given whatever resources are available. The default bearer may be associated with a particular IP address and a single UE may have further default bearers established. Each default bearer may be assigned a quality of service (QoS) class indicator (QCI) of 5 to 9 that relates to non-guaranteed bit rate (GBR) bearers. Applications that may utilize the default bearer may be those in which the delivery of data is less time sensitive. For example, signaling messages such as Session Initiation Protocol (SIP) may utilize the default bearer. Other examples include smartphone traffic including video, chat, email, browsing, etc. 
     A further type of bearer that may be established between the UE and the LTE-RAN  122  is a dedicated bearer. The dedicated bearer may provide a dedicated tunnel to specific traffic. One application that utilizes the dedicated tunnel is VoLTE voice data used when performing the VoLTE call. The dedicated bearer may be an additional bearer over the default bearer that is established at a time subsequent to the default bearer being established (e.g., upon performing the VoLTE call). Since only default bearers require separate IP addresses and the dedicated bearer is provided over an established default bearer, the dedicated bearer does not require a separate IP address. However, the dedicated bearer is linked to the default bearer established previously. Specifically, a value defined during setup of the dedicated bearer may be used to link the dedicated bearer to the default bearer. The dedicated bearer may utilize the same QCI as the default bearer but may also utilize a different QCI that relates to a GBR bearer. The dedicated bearer may use traffic flow templates (TFT) to provide the special treatment to specific services such as the VoLTE call. That is, the TFT may also define the rules of when the dedicated bearer is to be used based upon the application being executed. 
     When considering the operation of the default bearer and the dedicated bearer, the default bearer is established upon the UE connecting to the LTE-RAN  122 . Specifically, the LTE-RAN  122  assigns the default bearer to the UE. Subsequently, while still connected to the LTE-RAN  122 , the UE may execute the VoLTE call functionality. For example, the UE  110  may be the MO UE while the UE  112  may be the MT UE. As such, the MT UE may also be connected to the LTE-RAN  122  and have a default bearer assigned and established. When the VoLTE call functionality is performed, various signaling messages are transmitted between the UE  110  and the UE  112  via the LTE-RAN  122  and the IMS  150  through the respective default bearer. That is, a VoLTE call setup procedure may be performed. Once the VoLTE call has been established from successfully transmitting the different signaling messages, the UE  110  and the UE  112  may be connected to each other to perform the VoLTE call. Specifically, the dedicated bearer may be established for each of the UE  110  and the UE  112  for the VoLTE data to be transmitted. 
     The VoLTE call setup procedure may initially include the UE  110  establishing a connection to the IMS  150 . It should be noted that this operation of the setup procedure may be a more general operation that is performed at various other times and not necessarily be performed due to the VoLTE call being performed. For example, the connection to the IMS  150  may occur whenever the UE  110  has established a connection to the LTE-RAN  122 . However, it is also noted that in order to utilize the VoLTE call functionality, a connection to the IMS  150  may be required. 
     The connection to the IMS  150  may be performed through an initial association with the eNB of the LTE-RAN  122 . A subsequent connection may be established to the IMS  150  through various components of the IMS  150 . Specifically, an attach procedure may be performed in connecting the UE  110  to the IMS  150 . For example, the IMS  150  may include a mobility management entity (MME) and a packet data network (PDN) gateway (PGW). These components may be responsible for at least one operation when the VoLTE call functionality is used. Specifically, the MME may be a control-node for the LTE-RAN  122  that performs paging and tagging operations for an idle mode of the UE  110 . More specifically, the MME may perform operations related to bearer activation and/or deactivation. The MME may also select a serving gateway (SGW) at the initial attach with the IMS  150 . The SGW may be configured to route and forward data packets for the UE  110 . For example, the SGW may manage and store contexts for the UE  110  such as parameters of the bearer service, network internal routing information, etc. The MME may also authenticate the UE  110  (via the HSS) such that the services available to the UE  110  are identified including the VoLTE call functionality. The PGW may be configured to provide a connectivity between the UE  110  to an external PDN by being a point of entry/exit for data packet traffic for the UE  110 . It is noted that the IMS  150  may provide a connection to a plurality of PGW to access a corresponding number of PDN. Thus, the UE  110  may be enabled to exchange data packets with multiple PDNs via the PGW of the IMS  150 . During the attach procedure, the UE  110  may attach when a default access point name (APN) is an IMS APN and the IMS PDN is established during the default bearer determination. However, if the default APN is not the IMS APN, the IMD PDN may be established following the attach procedure. 
     Once the attach procedure is performed and the UE  110  has established a connection to the IMS  150 , an IMS registration procedure may be performed. The IMS registration procedure may enable the identified multimedia services to be accessed. Specifically, the IMS registration procedure may entail registering at least one IP Multimedia Public Identity (IMPU) such as a telephone number of the UE  110 . The IMS  150  may then authenticate an IP Multimedia Private Identity (IMPI). The registration process may be initiated by the UE  110  transmitting a SIP registration message to a proxy call session control function (CSCF) (P-CSCF). Using further message passing operations such as through an interrogating CSCF (I-CSCF) and a serving CSCF (S-CSCF), an authentication procedure may be performed via the HSS. With specific regard to the VoLTE call functionality, the IMS registration procedure may incorporate the P-CSCF and a policy and charging rules function (PCRF). The P-CSCF may be a SIP proxy providing a first point of contact for the UE  110  with the IMS  150 . The P-CSCF may also be disposed on a path of all signaling to inspect each signal ensuring that the UE  110  does not misbehave such as changing a known signaling route or disobeying a routing policy. The PCRF may determine policy rules in the IMS  150 . The PCRF aggregates information to and from the IMS  150  to support creation of the rules and make policy decisions for the multimedia services performed by the UE  110 . With particular regard to the VoLTE call functionality, the PCRF may be a mediator of network resources for the IMS  150  to establish the call and allocate the requested bandwidth to the dedicated bearer. 
     With the UE  110  having been attached to and registered with the IMS  150 , the user of the UE  110  may opt to perform the VoLTE call functionality. Thus, the VoLTE call setup procedure may receive the input from the user in performing this operation. For example, the user may launch a VoLTE call application and provide/select an identity of the MT UE  112 . To perform the VoLTE call, the UE  110  may transmit a SIP invite to the UE  112  via the P-CSCF. Specifically, the SIP invite may be transmitted to the P-CSCF which is forwarded to the UE  112 . The UE  112  may respond with a SIP: 100 trying signal back to the P-CSCF (e.g., an extended search requiring a significant amount of time triggers a forking proxy to send the 100 trying response) which is then forwarded back to the UE  110 . The UE  112  may also respond with a SIP: 183 session progress signal back to the P-CSCF (e.g., extra information for the VoLTE call while still in setup) which is then also forwarded back to the UE  110 . 
     Once the IMS  150  has determined that the VoLTE call is to be performed via the SIP signaling exchange, the P-CSCF may perform the operation to trigger the dedicated bearer for the VoLTE call. Specifically, a corresponding signal may be forwarded from the P-CSCF to the PCRF. The PCRF may also trigger the dedicated bearer for the VoLTE call. Specifically, a further corresponding signal may be forwarded from the PCRF to the PGW. Subsequently, the dedicated bearer may be established for the UE  110 . A further operation that may be performed is the QCI being set to 1 for the VoLTE call that is signaled from the MME to the eNB. With the dedicated bearer created and established, the VoLTE call may be performed by the UE  110 . 
     Those skilled in the art will understand that the conventional VoLTE call setup procedure utilizes the PGW to trigger the dedicated bearer established upon the P-CSCF initiating the triggering of the dedicated bearer for the VoLTE call and the PCRF confirming that there are sufficient resources for the dedicated bearer establishment. However, this portion of the VoLTE call setup procedure causes at least a 1 second delay that impacts the user experience in the setup. 
     Some aspects of the exemplary embodiments provide a mechanism by which the delay may be reduced and/or eliminated. That is, the mechanism according to the exemplary embodiments introduces a solution to save VoLTE call setup time. Specifically, the triggering of the dedicated bearer establishment may be performed using various different operations at a time prior to the conventional operation. As will be described in further detail below, the operations may be performed by the MO UE  110  and/or the IMS  150 . In a first set of mechanisms performed by the UE  110 , a first proposed mechanism may be updating a current radio resource control (RRC) procedure that uses a new cause identification; a second proposed mechanism may be updating a non-access-stratum (NAS) that uses the UE  110  requesting a dedicated bearer resource allocation procedure; and a third proposed mechanism may be updating the NAS with a new cause identification. In a second mechanism performed by the IMS  150 , a fourth proposed mechanism introduces a new policy and charging control (PCC) procedure. 
     In the first set of mechanisms performed by the UE  110 ,  FIG. 2  shows an exemplary UE  200  configured with dedicated bearer functionalities, according to some embodiments. Specifically, the UE  200  is configured to execute a plurality of applications that perform the respective functionalities of establishing the dedicated bearer for the VoLTE call according to the exemplary embodiments. Accordingly, the UE  200  of  FIG. 2  may correspond to the MO UE  110 . However, those skilled in the art will understand that the UE  200  may also represent the other UEs  112 ,  114 . However, it should be noted that the other UEs  112 ,  114  may not necessarily be capable of performing the functionalities described below with regard to the UE  110 . 
     The UE  200  may represent any electronic device that is configured to perform wireless functionalities and may be representative of one or more of the UEs  110 - 114 . For example, the UE  200  may be a portable device such as a smartphone, a tablet, a phablet, a laptop, a wearable, etc. In another example, the UE  200  may be a client stationary device such as a desktop terminal. The UE  200  may be configured to perform cellular and/or WiFi functionalities. The UE  200  may include a processor  205 , a memory arrangement  210 , a display device  215 , an input/output (I/O) device  220 , a transceiver  225 , and other components  230 . The other components  230  may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports to electrically connect the UE  200  to other electronic devices, etc. 
     The processor  205  may be configured to execute a plurality of applications of the UE  200 . For example, the applications may include a web browser when connected to a communication network via the transceiver  225 . As such, when connected to the LTE-RAN  122 , the data for the web browser may utilize the default bearer. In another example, the processor  205  may execute a VoLTE call application  235  that enables the UE  200  to perform a VoLTE call functionality such as with the UE  112 . The VoLTE call application  235  may further be configured to perform the VoLTE call setup procedure such as performing the steps described above. In yet another example, the processor  205  may execute a dedicated bearer application  240 . As will be described in further detail below, the dedicated bearer application  240  may perform the above noted mechanism of triggering the establishment of the dedicated bearer for use in the VoLTE call. That is, the dedicated bearer application  240  may be used in conjunction with the VoLTE call application  235 , particularly in the VoLTE call setup procedure. 
     It should be noted that the above noted applications each being an application (e.g., a program) executed by the processor  205  is only exemplary. The functionality associated with the applications may also be represented as a separate incorporated component of the UE  200  or may be a modular component coupled to the UE  200 , e.g., an integrated circuit with or without firmware. In addition, in some UEs, the functionality described for the processor  205  is split among two processors, a baseband processor and an applications processor. The exemplary embodiments may be implemented in any of these or other configurations of a UE. 
     The memory  210  may be a hardware component configured to store data related to operations performed by the UE  200 . Specifically, the memory  210  may store data related to the various applications  235 - 240 . For example, the VoLTE call application  235  may utilize a phone book functionality that stores contact information for other users and UEs. The display device  215  may be a hardware component configured to show data to a user while the I/O device  220  may be a hardware component that enables the user to enter inputs. It should be noted that the display device  215  and the I/O device  220  may be separate components or integrated together such as a touchscreen. 
     The transceiver  225  may be a hardware component configured to transmit and/or receive data. That is, the transceiver  225  may enable communication with other electronic devices directly or indirectly through a network based upon an operating frequency of the network. The transceiver  225  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies) that are related to the VoLTE call functionality. Thus, an antenna (not shown) coupled with the transceiver  225  may enable the transceiver  225  to operate on the LTE frequency band. 
       FIG. 3  shows a first exemplary signaling diagram  300  for establishing a dedicated bearer through a UE operation, according to some embodiments. As described above, the exemplary embodiments include a first set of mechanisms by which the MO UE  110  performs an operation to trigger the dedicated bearer in being established for the VoLTE call. The signaling diagram  300  relates to when the UE  110  executes the VoLTE call application  235  and the dedicated bearer application  240  in performing the VoLTE call setup procedure. Specifically, the signaling diagram  300  relates to the operation performed on the UE  110  such that the dedicated bearer is established in such a way that the delay caused from the signaling between the P-CSCF and the PCRF after the SIP signaling is reduced and/or eliminated. It may be assumed that the other MT UE  112  is also capable of performing the VoLTE call and properly performs all necessary operations in establishing the VoLTE call. 
     The signaling diagram  300  illustrates a VoLTE call setup procedure. The signaling diagram  300  includes substantially similar operations as described above. Initially, the MO UE  110  may establish a connection with an eNB  122 A of the LTE-RAN  122  as well as the IMS  150  using an attachment procedure  305 . Specifically, the UE  110  may detect the presence of the LTE-RAN  122  and transmit a connection request to the eNB  122 A. Upon performing an association procedure, the UE  110  may establish a connection to the LTE-RAN  122  via the eNB  122 A. Furthermore, upon establishing the connection the LTE-RAN  122 , the eNB  122 A may assign a default bearer for the UE  110  and establish the default bearer. The attachment procedure  305  may therefore also be utilized with components of the IMS  150  such as a MME  150 A and a PGW  150 B. The attachment procedure  305  may be substantially identical to the attachment procedure described above. The MO UE  110  may also perform an IMS registration  310  upon connecting to the IMS  150 . The IMS registration  310  may therefore further be utilized with components of the IMS  150  such as a PCRF  150 C and a P-CSCF  150 D. It should be noted that the MT UE  112  may perform substantially similar operations (not shown) to connect to the LTE-RAN  122  and the IMS  150 . 
     With the UE  110  connected to the LTE-RAN  122  and the IMS  150  and the IMS registration procedure completed to indicate that the UE  110  is configured to perform the VoLTE call functionality, the UE  110  may execute the VoLTE call application  235 . The initiation of the VoLTE call application  235  may be used to initiate the operations performed by the dedicated bearer application  240 . Specifically, according to the first exemplary mechanism, the RRC establishment  315  may be performed. Although the conventional operations of the RRC establishment may also be performed, the exemplary embodiments further utilize a new cause identification. Specifically, the RRC establishment  315  includes a new RRC establishment cause to the LTE-RAN  122  via a signaling to the eNB  122 A. When the RRC establishment is due to the MO UE  110  performing a voice call, the MO UE  110  may signal a VoLTE cause identification to indicate to the LTE-RAN  122  to reserve a QCI1 (i.e., a QCI with value of 1) resource and trigger a dedicated bearer establishment after the RRC establishment  315 . It is noted that a video call may reserve the QCI1 as well as a QCI2. Thus, the triggering of the dedicated bearer establishment may now be an operation that is performed while the further signaling in the VoLTE call setup procedure is being performed. Therefore, in this mechanism, it may be considered that the dedicated bearer establishment and the VoLTE call setup procedure are performed in parallel. In this manner, the VoLTE call setup procedure is no longer required to wait until after the SIP 183 signaling to be completed in triggering the dedicated bearer. 
     After the RRC establishment procedure  315  has been completed, the remaining operations of the VoLTE call setup procedure may be performed in addition to the parallel execution of the triggering of the dedicated bearer. Thus, the SIP signaling may be performed in which the SIP invite  320  may be transmitted from the MO UE  110  to the P-CSCF  150 D; the SIP invite  325  may be transmitted from the P-CSCF to the MT UE  112 ; the SIP: 100 trying  330  may be transmitted from the MT UE  112  to the P-CSCF  150 D, the 100 trying signal  335  may be transmitted from the P-CSCF  150 D to the MO UE  110 ; the SIP: 183 session progress  340  may be transmitted from the MT UE  112  to the P-CSCF  150 D; and the SIP: 183 session progress  345  may be transmitted from the P-CSCF  150 D to the MO UE  110 . While this SIP signaling is being performed, the signal to trigger the dedicated bearer  350  may be transmitted from the P-CSCF  150 D to the PCRF  150 C; and the signal to trigger the dedicated bearer  355  may be transmitted from the PCF  150 C to the PGW  150 B. Accordingly, the dedicated bearer  360  is established and the VoLTE call may be performed. 
     It is noted that although the signaling diagram  300  appears to show such that the dedicated bearer is triggered after the SIP: 183 session progress signaling, it is noted that this is not representative of the operations of the exemplary embodiments. In contrast, the SIP signaling including the invite, the 100 trying, and the 183 session progress may be performing in the order shown, but the triggering of the dedicated bearer may be performed in parallel to these SIP signaling and is not performed after the SIP signaling. 
       FIG. 4  shows a second exemplary signaling diagram  400  for establishing a dedicated bearer through a UE operation, according to some embodiments. The signaling diagram  400  relates to when the UE  110  executes the VoLTE call application  235  and the dedicated bearer application  240  in performing the VoLTE call setup procedure. That is, the signaling diagram  400  also relates to the first set of mechanisms by which the MO UE  110  performs an operation to trigger the dedicated bearer in being established for the VoLTE call. The signaling diagram  400  relates to the operation performed on the UE  110  such that the dedicated bearer is established in such a way that the delay caused from the signaling between the P-CSCF  150 D and the PCRF  150 C after the SIP signaling is reduced and/or eliminated. It may be assumed that the other MT UE  112  is also capable of performing the VoLTE call and properly performs all necessary operations in establishing the VoLTE call. 
     The signaling diagram  400  illustrates a VoLTE call setup procedure. The signaling diagram  400  includes substantially similar operations as described above, particularly with regard to the signaling diagram  300  of  FIG. 3 . Thus, the MO UE  110  may perform an attachment procedure  405  and an IMS registration  410 . With the UE  110  connected to the LTE-RAN  122  and the IMS  150  and the IMS registration procedure completed to indicate that the UE  110  is configured to perform the VoLTE call functionality, the UE  110  may execute the VoLTE call application  235 . The initiation of the VoLTE call application  235  may again be used to initiate the operations performed by the dedicated bearer application  240 . Specifically, according to the second exemplary mechanism, the RRC establishment and service request (SR)  415  and the uplink (UL) information transfer  420  may be performed. The RRC establishment and SR  415  may relate to a conventional procedure. Therefore, conventional operations may be performed in establishing the RRC and transmitting the appropriate SR to perform the VoLTE call such as when the MO UE  110  is in the RRC idle state. It is noted that the RRC establishment and SR  415  may not be performed. For example, the MO UE  112  may already be in a RRC connected state which may then only entail the MO UE  110  sending the UL information transfer  420 . The UL information transfer  420  may be a follow-up procedure upon completing the RRC establishment and SR  415  or a parallel procedure along with the RRC establishment and SR  415 . The UL information transfer  420  may be a signaling process from the MO UE  110  to the MME  150 A. The UL information transfer  420  may be a dedicated bearer resource allocation request from the UE  110 . Accordingly, the PGW  150 B may trigger a QCI1 establishment from receiving the request to establish the QCI1 dedicated bearer for the VoLTE call. In this manner, the VoLTE call setup procedure is no longer required to wait until after the SIP 183 signaling to be completed in triggering the dedicated bearer. 
     In a particular exemplary embodiment, the Third Generation Partnership Project (3GPP) Technical Specification (TS)  24 . 301  defines a UE procedure. However, the resources are ultimately controlled by the LTE-RAN  122  and not substantially used as a UE-side operation. The second mechanism described above according to the exemplary embodiments utilize this procedure for QCI1 establishment while the VoLTE call is triggered. Accordingly, the UL information transfer  420  may be a message used for an UL transfer of NAS or non-3GPP dedicated information. Through adaptation of this message, the UL information transfer  420  may be utilized for the purposes described above. 
     After the UL information transfer  420  has been completed, the remaining operations of the VoLTE call setup procedure may be performed in addition to the parallel execution of the triggering of the dedicated bearer. Thus, the SIP signaling may be performed in which the SIP invite  425  may be transmitted from the MO UE  110  to the P-CSCF  150 D; the SIP invite  430  may be transmitted from the P-CSCF to the MT UE  112 ; the SIP: 100 trying  435  may be transmitted from the MT UE  112  to the P-CSCF  150 D, the 100 trying signal  335  may be transmitted from the P-CSCF  150 D to the MO UE  110 ; the SIP: 183 session progress  445  may be transmitted from the MT UE  112  to the P-CSCF  150 D; and the SIP: 183 session progress  450  may be transmitted from the P-CSCF  150 D to the MO UE  110 . While this SIP signaling is being performed, the signal to trigger the dedicated bearer  455  may be transmitted from the P-CSCF  150 D to the PCRF  150 C; and the signal to trigger the dedicated bearer  460  may be transmitted from the PCF  150 C to the PGW  1503 . Accordingly, the dedicated bearer  465  is established and the VoLTE call may be performed. 
     It is again noted that although the signaling diagram  400  appears to show such that the dedicated bearer is triggered after the SIP: 183 session progress signaling, it is noted that this is not representative of the operations of the exemplary embodiments. In contrast, the SIP signaling including the invite, the 100 trying, and the 183 session progress may be performing in the order shown, but the triggering of the dedicated bearer may be performed in parallel to these SIP signaling and is not performed after the SIP signaling. 
       FIG. 5  shows a third exemplary signaling diagram  500  for establishing a dedicated bearer through a UE operation, according to some embodiments. The signaling diagram  500  relates to when the UE  110  executes the VoLTE call application  235  and the dedicated bearer application  240  in performing the VoLTE call setup procedure. That is, the signaling diagram  500  further relates to the first set of mechanisms by which the MO UE  110  performs an operation to trigger the dedicated bearer in being established for the VoLTE call. The signaling diagram  500  relates to the operation performed on the UE  110  such that the dedicated bearer is established in such a way that the delay caused from the signaling between the P-CSCF  150 D and the PCRF  150 C after the SIP signaling is reduced and/or eliminated. It may be assumed that the other MT UE  112  is also capable of performing the VoLTE call and properly performs all necessary operations in establishing the VoLTE call. 
     The signaling diagram  500  illustrates a VoLTE call setup procedure. The signaling diagram  500  includes substantially similar operations as described above, particularly with regard to the signaling diagram  300  of  FIG. 3 . Thus, the MO UE  110  may perform an attachment procedure  505  and an IMS registration  510 . With the UE  110  connected to the LTE-RAN  122  and the IMS  150  and the IMS registration procedure completed to indicate that the UE  110  is configured to perform the VoLTE call functionality, the UE  110  may execute the VoLTE call application  235 . The initiation of the VoLTE call application  235  may again be used to initiate the operations performed by the dedicated bearer application  240 . 
     Specifically, according to the third exemplary mechanism, the RRC establishment  515  and the SR  520  may be performed. The RRC establishment  515  may relate to a conventional procedure. Therefore, conventional operations may be performed in establishing the RRC to perform the VoLTE call such as when the MO UE  110  is in a RRC idle state. It is again noted that if the MO UE  110  is already in the RRC connected state, the RRC establishment  515  may not be performed. The SR  520  may be a follow-up procedure upon completing the RRC establishment  515  or a parallel procedure along with the RRC establishment  515 . Although the conventional operations of the SR may also be performed, the exemplary embodiments include further information in the SR  520 . Thus, the SR  520  may provide the basis upon which the dedicated bearer establishment is triggered while the remaining operations of the VoLTE call setup procedure are performed. In this manner, the VoLTE call setup procedure is no longer required to wait until after the SIP 183 signaling to be completed in triggering the dedicated bearer. 
     In a particular exemplary embodiment, the SR  520  may include a new security header type if the SR  520  is triggered by a voice call such as the VoLTE call. Thus, if the SR  520  is due to a voice call, the NAS may use a special security header type to indicate to the LTE-RAN  122  to reserve the QCI1 resource and trigger the dedicated bearer establishment after the SR  520  is completed. Again, referring to the 3GPP TS 24.301 and particularly to Table 9.3.1, the security header type (octet  1 ) includes a set of variables that are not used in the defined version of the protocol. Accordingly, the values may be adapted for use in the third mechanism of the exemplary embodiments. 
     After the SR  520  has been completed, the remaining operations of the VoLTE call setup procedure may be performed in addition to the parallel execution of the triggering of the dedicated bearer. Thus, the SIP signaling may be performed in which the SIP invite  425  may be transmitted from the MO UE  110  to the P-CSCF  150 D; the SIP invite  430  may be transmitted from the P-CSCF to the MT UE  112 ; the SIP: 100 trying  435  may be transmitted from the MT UE  112  to the P-CSCF  150 D, the 100 trying signal  335  may be transmitted from the P-CSCF  150 D to the MO UE  110 ; the SIP: 183 session progress  445  may be transmitted from the MT UE  112  to the P-CSCF  150 D; and the SIP: 183 session progress  450  may be transmitted from the P-CSCF  150 D to the MO UE  110 . While this SIP signaling is being performed, the signal to trigger the dedicated bearer  455  may be transmitted from the P-CSCF  150 D to the PCRF  150 C; and the signal to trigger the dedicated bearer  460  may be transmitted from the PCF  150 C to the PGW  150 B. Accordingly, the dedicated bearer  465  is established and the VoLTE call may be performed. 
     It is again noted that although the signaling diagram  400  appears to show such that the dedicated bearer is triggered after the SIP: 183 session progress signaling, it is noted that this is not representative of the operations of the exemplary embodiments. In contrast, the SIP signaling including the invite, the 100 trying, and the 183 session progress may be performing in the order shown, but the triggering of the dedicated bearer may be performed in parallel to these SIP signaling and is not performed after the SIP signaling. 
     It is also again noted that the use of the VoLTE call is only exemplary and that the VoLTE may be a component of a video call. Accordingly, the description above may also be applied to the video call. Those skilled in the art will understand that the use of the video call may include further aspects. The exemplary embodiments may be modified to accommodate these further aspects in performing the video call, particularly over the LTE-RAN  122  and/or the IMS  150 . For example, when using the video call, the operations of the exemplary embodiments may further require the QCI2 (for the video) in addition to the QCI1 (for the voice). In another example, when using the video call, the exemplary embodiments may utilize a first security header in the third mechanism for the VoLTE call and a second security header for the video call. 
       FIG. 6  shows an exemplary method  600  for establishing a dedicated bearer through a UE operation, according to some embodiments. Specifically, the method  600  relates to when the UE  110  executes the dedicated bearer application  240  when the UE  110  is the MO in performing the VoLTE call. Thus, the method  600  relates to the first set of mechanisms in which the MO UE  110  performs an operation to trigger the dedicated bearer establishment. Again, it may be assumed that the UE  112 , which is the other party to the VoLTE call, has performed all necessary operations to also participate in the VoLTE call. The method  600  will be described with regard to the UE  110 . The method  600  will be described with reference to the network arrangement  100  of  FIG. 1 , the UE  200  of  FIG. 2 , and the signaling diagrams  300 ,  400 ,  500  of  FIGS. 3, 4, 5 , respectively. 
     In step  605 , the UE  110  establishes a connection to the IMS  150 . As discussed above, the UE  110  may initially establish a connection to the LTE-RAN  122  via the eNB  122 A. Through the various interconnections between the networks, the UE  110  may also connect to the IMS  150  via the LTE-RAN  122  and the cellular core network  130 . Various further operations associated with connecting to the different networks and IMS  150  may be performed such as establishing a default bearer for the UE  110 . In step  610 , the UE  110  may register with the IMS  150 . That is, once connected thereto, the registration process may be performed to, among other reasons, determine the multimedia services to be provided or are capable by the UE  110  such as the VoLTE call. 
     In step  615 , the UE  110  receives an input to initiate a VoLTE call. As discussed above, the UE  110  may include a VoLTE call application  235 . The user may launch the VoLTE call application  235 . The user may also select an identity of the MT UE  112  to perform the VoLTE call. These may be indications or inputs that initiate the VoLTE call. 
     In step  620 , the UE  110  may execute the dedicated bearer application  240 . The dedicated bearer application  240  may perform an operation to trigger the dedicated bearer in being established for the VoLTE call. As discussed above, the operations may relate to the first set of mechanisms in which the operation relates to a process prior to a SIP signal exchange for the VoLTE call. In the first mechanism, the RRC establishment  315  may include a VoLTE cause identification that notifies the eNB  122 A to trigger the dedicated bearer establishment. In the second mechanism, the UL information transfer  420  may include a NAS update by using a dedicated bearer resource allocation request from the UE  110 . In the third mechanism, the SR  520  may include a NAS update with a new cause identification using a security header type. Accordingly, the first set of mechanisms relate to generating and transmitting a modified data packet to indicate to the LTE-RAN  122  and/or the IMS  150  to trigger the procedure in establishing the dedicated bearer. 
     In step  625 , the VoLTE call setup procedure may be performed. Specifically, the setup procedure may relate to a remainder of the processes including the SIP signaling exchange between the MO UE  110  and the MT UE  112  (e.g., via the P-CSCF  150 D). Thus, the SIP invite, the SIP 100 trying, and the SIP 183 session progress may be exchanged in establishing the VoLTE call. Furthermore, while the SIP signaling exchange is being performed, the dedicated bearer may be established concurrently from the preliminary dedicated bearer operation being performed in step  620 . That is, this aspect of the VoLTE call setup procedure of establishing the dedicated bearer may be triggered to be performed at the same time that the SIP signals are being exchanged. Subsequently, in step  630 , the VoLTE call may be performed. 
       FIG. 7  shows an exemplary signaling diagram  700  for establishing a dedicated bearer through a network operation, according to some embodiments. The signaling diagram  700  relates to when the IMS  150  performs the VoLTE call setup procedure in a way that the dedicated bearer is established upon receiving an indication that its use may be required. That is, the signaling diagram  700  relates to the second mechanism by which the IMS  150  utilizes a different policy and charging control procedure to trigger the dedicated bearer in being established for the VoLTE call. The signaling diagram  700  relates to the operation performed on the IMS  150  such that the dedicated bearer is established in such a way that the delay caused from the signaling between the P-CSCF  150 D and the PCRF  150 C after the SIP signaling is reduced and/or eliminated. 
     The signaling diagram  700  illustrates a VoLTE call setup procedure. The signaling diagram  700  includes substantially similar operations as described above, particularly with regard to the signaling diagram  300  of  FIG. 3 . Thus, the MO UE  110  may perform an attachment procedure  705  and an IMS registration  710 . The UE  110  may also initiate the VoLTE call. However, since the signaling diagram  700  relates to a network operation, the IMS  150  may determine the VoLTE call initiation upon receiving the SIP invite  715  by the P-CSCF  150 D. 
     Once the P-CSCF  150 D has received the SIP invite  715  from the MO UE  110 , the IMS  150  may perform subsequent operations. A conventional operation may be to forward the SIP invite  720  from the P-CSCF  150 D to the MT UE  112 . According to the exemplary embodiments, P-CSCF  150 D further triggers the dedicated bearer operation. That is, the P-CSCF  150 D may trigger the dedicated bearer  725  for the VoLTE call immediately upon receiving the SIP invite  715 . The P-CSCF  150 D may also mark the triggering of the dedicated bearer as a high policy and charging control to the PCRF  150 C. This may ensure that the PGW  150 B triggers the dedicated bearer  730  immediately when the PCRF normally may not send for the dedicated bearer until after the SIP signal exchange has completed (or after the SIP: 183 session progress has been exchanged). 
     The remainder of the signaling diagram  700  may be to the other operations in establishing the VoLTE call in addition to the parallel execution of the triggering of the dedicated bearer. Thus, the SIP: 100 trying  735  may be transmitted from the MT UE  112  to the P-CSCF  150 D; the 100 trying signal  740  may be transmitted from the P-CSCF  150 D to the MO UE  110 ; the SIP: 183 session progress  745  may be transmitted from the MT UE  112  to the P-CSCF  150 D; and the SIP: 183 session progress  750  may be transmitted from the P-CSCF  150 D to the MO UE  110 . Accordingly, the dedicated bearer  755  is established and the VoLTE call may be performed. In this manner, the VoLTE call setup procedure is no longer required to wait until after the SIP 183 signaling to be completed in triggering the dedicated bearer. 
     It is again noted that although the signaling diagram  700  appears to show such that the dedicated bearer is triggered prior to any of the SIP signaling, it is noted that this is not representative of the operations of the exemplary embodiments. In contrast, the SIP signaling including the invite, the 100 trying, and the 183 session progress may be performed in the order shown, but the triggering of the dedicated bearer may be performed in parallel to these SIP signaling and is not performed after the SIP signaling. 
       FIG. 8  shows an exemplary method  800  for establishing a dedicated bearer through a network operation, according to some embodiments. Specifically, the method  800  relates to when the IMS  150  performs an operation to trigger the dedicated bearer establishment. Thus, the method  800  relates to the second mechanism in which the P-CSCF  150 D performs the operation to trigger the dedicated bearer establishment. Again, it may be assumed that the UEs  110 ,  112  have performed all necessary operations to participate in the VoLTE call. The method  800  will be described with regard to the IMS  150 . The method  800  will be described with reference to the network arrangement  100  of  FIG. 1 , the UE  200  of  FIG. 2 , and the signaling diagram  700  of  FIG. 7 . 
     In step  805 , the IMS  150  receives a SIP invite for the VoLTE call from the MO UE  110 . Specifically, the SIP invite  715  may be received by the P-CSCF  150 D. In steps  810  and  815 , the IMS  150  may perform a conventional operation and an operation according to the exemplary embodiments, respectively. Specifically, in step  810 , the IMS  150  may forward the SIP invite  720  from the P-CSCF  150 D to the MT UE  112 . In step  815 , the IMS  150  may trigger the dedicated bearer operation in parallel. That is, upon receiving the SIP invite  715  by the P-CSCF  150 D from the MO UE  110 , the IMS  150  may simultaneously perform these operations. In step  820 , the IMS  150  may perform the further and remaining VoLTE setup procedure operations. Specifically, the remaining SIP signaling exchanges (e.g., SIP 100 and SIP 183) may be performed. Concurrently, the IMS  150  may continue to establish the dedicated bearer for use in the VoLTE call. Thus, in step  825 , the VoLTE call may be performed. 
     The exemplary embodiments provide a device, system, and method of enhancing a VoLTE call setup procedure. Specifically, the VoLTE call setup procedure may be enhanced by reducing and/or eliminating delays through a modified timing of triggering an establishment for a dedicated bearer to be used in the VoLTE call. Specifically, the procedure in establishing the dedicated bearer may be performed while the SIP signaling exchange for the VoLTE call setup procedure is also being performed, concurrently. In a first set of mechanisms, the enhancement may be performed through an operation of the UE. In a second mechanism, the enhancement may be performed through an operation of the IMS. 
     Those skilled in the art will understand that the above-described exemplary embodiments may be implemented in any suitable software or hardware configuration or combination thereof. An exemplary hardware platform for implementing the exemplary embodiments may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. In a further example, the exemplary embodiments of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor. 
     It will be apparent to those skilled in the art that various modifications may be made in the present invention, without departing from the spirit or the scope of the invention. Thus, it is intended that the present invention cover modifications and variations of this invention provided they come within the scope of the appended claims and their equivalent.

Metadata:
Filing Date: 20150828
Publication Date: 20210330
Grant Date: 20210330
Priority Date: 20150828
Inventors: LIANG, HUARUI
ZHANG, DAWEI
LI, Shangfeng
SUN, HAO
WANG, ZHIWEI
Assignee: APPLE INC
CPC Classifications: [{"code": "H04L65/1104", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1104", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1073", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1073", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/27", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L12/66", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04W76/12", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L65/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/12", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L65/1069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/80", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1006", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1073", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/27", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L65/1069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L12/66", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L65/1016", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/12", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 58186465