WO2012025666A1

WO2012025666A1 - Method and apparatus for implementing communications session continuity

Info

Publication number: WO2012025666A1
Application number: PCT/FI2011/050722
Authority: WO
Inventors: Jari Mutikainen
Original assignee: Nokia Inc
Current assignee: Nokia Inc
Priority date: 2010-08-23
Filing date: 2011-08-18
Publication date: 2012-03-01
Anticipated expiration: 2013-02-23

Abstract

An example method for implementing communications session continuity is provided. The example method may include causing a message to be sent, from a user equipment, requesting a codec. In this regard, the user equipment may be connected to a circuit switched access network. The example method may further include receiving a response including at least an indication of the codec, and causing bearer resources to be reserved. The codec may be used for communications via a bearer that is established with the bearer resources. The example method may further include causing a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources. Other related example methods, apparatuses, computer programs, and computer program products are also provided.

Description

METHOD AND APPARATUS FOR IMPLEMENTING COMMUNICATIONS

SESSION CONTINUITY

TECHNICAL FIELD

[0001] Embodiments of the present invention relate generally to communications technology, and, more particularly, relate to a method and apparatus for facilitating a radio transfer from one communications technology to another.

BACKGROUND

[0002] The iterative evolution of communications technology, for example in the realm of cellular communications technology, has created situations where user equipment (UE) must be capable of transitioning between state-of-the-art communications systems and legacy communications with minimal to no impact on quality of service. To perform these transitions between technologies during, for example, a continuous communications session, a variety of issues should be considered to prevent the quality of service from being significantly impacted. These issues become increasingly important to consider when, for example, a UE includes only a single radio and the radio must transition between the technologies without causing a noticeable interruption in the connection. SUMMARY OF SOME EXAMPLE EMBOIDMENTS

[0003] Example methods and example apparatuses are described herein that provide for implementing communications session or voice call continuity. In this regard, according to some example embodiments, a UE may be configured to request, and an access network entity may be configured to provide in response to the request, a selected codec prior to initiating and performing a handover from a first connection to a second connection. The first connection may be a circuit switched access connection and the second connection may be a packet switched access connection. Additionally, the selected codec and a negotiated port on the UE may be used by the access network entity to cause bearer resources to be reserved, and possible establishment of the bearer, prior to the handover procedure.

[0004] According to some example embodiments, a method is provided. The example method may include causing a message to be sent, from a user equipment, requesting a codec. In this regard, the user equipment may be connected to a circuit switched access network. The example method may further include receiving a response including at least an indication of the codec, and causing bearer resources to be reserved. The codec may be used for communications via a bearer that is established with the bearer resources. The example method may further include causing a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources. According to some other example embodiments, a computer program is provided that, when executed, causes an apparatus to perform the example method.

[0005] According to some example embodiments, an apparatus is provided. The example apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, direct the apparatus to perform various functionality. In this regard, the example apparatus may be directed to cause a message to be sent, from a user equipment, requesting a codec. The user equipment may be connected to a circuit switched access network. The example apparatus may also be directed to receive a response including at least an indication of the codec, and cause bearer resources to be reserved. The codec may be used for communications via a bearer that is established with the bearer resources. Further, the example apparatus may also be directed to cause a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

[0006] According to some example embodiments, another apparatus is provided. The example apparatus may include means for causing a message to be sent, from a user equipment, requesting a codec. In this regard, the user equipment may be connected to a circuit switched access network. The example apparatus may further include means for receiving a response including at least an indication of the codec, and means for causing bearer resources to be reserved. The codec may be used for communications via a bearer that is established with the bearer resources. Further, the example apparatus may further include means for causing a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

[0007] According to some example embodiments, a computer program product is provided. The example computer program product may include at least one computer- readable medium having instructions stored thereon, the instructions being configured to, when executed, direct an apparatus to perform various functionality. In this regard, the instructions may direct the apparatus to cause a message to be sent, from a user equipment, requesting a codec. The user equipment may be connected to a circuit switched access network. The instructions may also direct the apparatus to receive a response including at least an indication of the codec, and cause bearer resources to be reserved. The codec may be used for communications via a bearer that is established with the bearer resources. Further, the instructions may also direct the apparatus to cause a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

[0008] Further, according to some example embodiments, another method is provided. The example method may include receiving a message from a user equipment requesting a codec. The user equipment may be connected to a circuit switched access network. The example method may further include causing a response to be provided to the user equipment including the codec or an indication of the codec, and causing bearer resources to be reserved. The codec may be used for communications via the bearer that is established using the bearer resources. The example method may also include causing a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

According to some other example embodiments, a computer program is provided that, when executed, causes an apparatus to perform the example method.

[0009] According to some example embodiments, another apparatus is provided.

The example apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, direct the apparatus to perform various functionality. In this regard, the example apparatus may be directed to receive a message from a user equipment requesting a codec. The user equipment may be connected to a circuit switched access network. The example apparatus may be further directed to cause a response to be provided to the user equipment including the codec or an indication of the codec, and cause bearer resources to be reserved. The codec may be used for communications via the bearer that is established using the bearer resources. The example apparatus may be further directed to cause a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

[0010] Further, according to some example embodiments, another apparatus is provided. The example apparatus may include means for receiving a message from a user equipment requesting a codec. The user equipment may be connected to a circuit switched access network. The example apparatus may further include means for causing a response to be provided to the user equipment including the codec or an indication of the codec, and means for causing bearer resources to be reserved. The codec may be used for communications via the bearer that is established using the bearer resources. The example apparatus may also include means for causing a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

[0011] According to some example embodiments, another computer program product is provided. The example computer program product may include at least one computer-readable medium having instructions stored thereon, the instructions being configured to, when executed, direct an apparatus to perform various functionality. In this regard, the instructions may direct the apparatus to receive a message from a user equipment requesting a codec. The user equipment may be connected to a circuit switched access network. The instructions may further direct the apparatus to cause a response to be provided to the user equipment including the codec or an indication of the codec, and cause bearer resources to be reserved. The codec may be used for

communications via the bearer that is established using the bearer resources. The instructions may further direct the apparatus to cause a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources. BRIEF DESCRIPTION OF THE DRAWING(S)

[0012] Reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:

[0013] FIG. la illustrates an example user equipment and indicates a transition from a circuit switched access network to a packet switched access network according to an example embodiment of the present invention;

[0014] FIG. lb illustrates a flow chart of operations performed by a user equipment when transitioning from a circuit switched access network to a packet switched access network according to an example embodiment of the present invention;

[0015] FIG. 2 illustrates a signaling diagram for conducting an example reverse single radio voice call continuity procedure according to an example embodiment of the present invention;

[0016] FIG. 3 illustrates a block diagram of an apparatus and associated system for implementing communications session continuity according to an example embodiment of the present invention; [0017] FIG. 4 illustrates a block diagram of a mobile terminal configured for implementing communications session continuity according to an example embodiment of the present invention;

[0018] FIG. 5 is a flowchart of an example method for implementing

communications session continuity from the perspective of a user equipment according to an example embodiment of the present invention; and

[0019] FIG. 6 is a flowchart of an example method for implementing

communications session continuity from the perspective of a network entity according to an example embodiment of the present invention. DETAILED DESCRIPTION

[0020] Example embodiments of the present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which some, but not all embodiments of the invention are shown. Indeed, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like reference numerals refer to like elements throughout. The terms "data," "content," "information," and similar terms may be used

interchangeably, according to some example embodiments of the present invention, to refer to data capable of being transmitted, received, operated on, and/or stored.

[0021] As used herein, the term 'circuitry' refers to all of the following: (a) hardware-only circuit implementations (such as implementations in only analog and/or digital circuitry); (b) to combinations of circuits and software (and/or firmware), such as (as applicable): (i) to a combination of processor(s) or (ii) to portions of

processor(s)/software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions); and (c) to circuits, such as a microprocessor(s) or a portion of a microprocessor(s), that require software or firmware for operation, even if the software or firmware is not physically present.

[0022] This definition of 'circuitry' applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term "circuitry" would also cover an implementation of merely a processor (or multiple processors) or portion of a processor and its (or their) accompanying software and/or firmware. The term "circuitry" would also cover, for example and if applicable to the particular claim element, a baseband integrated circuit or applications processor integrated circuit for a mobile phone or a similar integrated circuit in a server, a cellular network device, or other network device.

[0023] Example methods and example apparatuses are described herein that provide for implementing communications session or voice call continuity. In this regard, according to some example embodiments, a UE (user equipment) may be configured to transition from a communications connection with a circuit switched (CS) network to a packet switched (PS) network, while maintaining continuity of a communications session. FIG. la provides a depiction of a UE 150 performing such a transition from the CS access network 110 to the PS access network 111. The UE 150 may be any type of wireless communications device that is configured to communicate with various communications networks using associated wireless communications protocols. According to some example embodiments, the UE 150 may include a single radio, and therefore transitions from a first network using a first communications technology to a second network using a second communications technology may include reconfiguration of the radio and supporting hardware and software during the transition. Where voice calls are part of the communications session to be transferred, transitions of this nature may be referred to as Single Radio Voice Call Continuity (SRVCC) procedures. In instances where the UE 150 is transitioning from a CS access network to a PS access network, as depicted in FIG. 1, the transition may be referred to as a reverse SRVCC (rSRVCC). More specifically, a rSRVCC procedure may involve a transition of a UE's communications session from a UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network) to an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access Network/High Speed Packet Access) or an IMS (Internet protocol Multimedia Subsystem) over LTE (Long Term Evolution) session. In some example embodiments, an rSRVCC procedure, such those described in 3^rd

Generation Partnership Project (3GPP) Technical Report (TR) 23.885 vO.2.0, may be combined with enhanced SRVCC (eSRVCC) techniques, such as those described in 3GPP TR 23.856 VO.2.0 to form a common architecture for a transition. It is contemplated that references to the rSRVCC procedure herein, may, but need not, include aspects of the eSRVCC techniques.

[0024] In this regard, a SIP (Session Initiation Protocol) based solution may be used to facilitate an rSRVCC procedure involving an ATCF (Access Transition Control Function). The ATCF may be an entity in the visited PLMN (Public Land Mobile Network) that anchors the SIP session and controls media anchoring in the ATGW (Access Transition Gateway). Via SIP, anchoring of the user and media planes in the serving PLMN may also be performed. To minimize an interruption of speech communications during an rSRVCC procedure, the serving PLMN can be informed of the IP (internet protocol) address and port that the UE is planning to use for the RTP (real-time transport protocol) speech media in the IMS over LTE session after the rSRVCC procedure is complete. The port number may be a pre-fixed port number for the UE, or the port number may be negotiated, possibly during the SIP registration. By using the IP address and port number of the UE, the ATFC/ATGW (the anchoring node in the serving PLMN) may be able to initiate a bearer, such as the QCI=1 (Quality of Service Class Identifier - Conversational Voice) voice media bearer that may be used subsequent to completion of the rSRVCC procedure. The bearer may be established, for example, through the PCRF (Policy Changing Rules Function). The ATFC/ATGW may also re-route the media path towards this bearer, during the rSRVCC procedure, and before the UE has switched the

UE's radio to LTE.

[0025] In addition to utilizing the IP address and the port number to establish the bearer, the voice codec may be negotiated and shared between the UE and the ATCF. In a first example instance, the UE and ATCF may be informed of the selected codec to be used when the rSRVCC procedure is complete. To determine the codec to be used, the UE may send a supported codec list after the registration phase (e.g., in the SIP

REGISTER) to the ATCF. When the rSRVCC occurs, the ATCF may select a codec from the received list, and inform the UE of the codec selection in a HO (handover) command message. However, providing codec selection in the HO command message may cause the QCI=1 media bearer to be initiated after the rSRVCC procedure has been started, which may delay or lengthen the duration of the rSRVCC procedure. This technique of using the HO command message to inform the UE of the codec selection by the ATCF may also cause the use of additional interfaces and communications between the ATCF and the PCRF to initiate the QCI=1 bearer.

[0026] An alternative to this technique is to reserve the bearer, and inform the UE of the selected codec, prior to the rSRVCC procedure. In other words, the QCI=1 bearer for use after the transfer may be reserved before the rSRVCC procedure begins. In some example embodiments, the bearer may be reserved after, or possibly immediately after, IMS registration by the UE. [0027] FIG. lb is a flowchart of an example method that operates to reserve the bearer prior to commencing the rSRVCC procedure. At 120, the UE may attach, or be previously attached, to the CS access network and perform IMS registration, possibly via SIP. At 121 , the UE may send an INVITE with an SDP (Session Description Protocol) offer towards the ATCF. The INVITE may operate as a request by the UE for a codec selection. The INVITE may be addressed by the UE using the ATCF's URI (uniform resource identifier), which may have been determined during SIP registration.

Alternatively, a pre-configured URI for the ATCF may be used. Use of the URI of the ATCF in the INVITE may indicate to the ATCF, that the ATCF is the final target for the SIP session. Additionally, a P-CSCF (Proxy Call Session Control Function) may route the INVITE to the ATCF using a route set that was created during SIP registration.

[0028] The ATFC may respond to the UE with, and the UE may receive at 122, an

SDP answer with an indication of the selected codec. Additionally, the port number for use with the bearer may be negotiated using SDP offer/answer procedures at this time. The P-CSCF may contact the PCRF using IMS procedures, and the PCRF may be informed that the media reservation for the bearer is for rSRVCC preparation. To inform the PCRF, a pre-defined media authorization rule may be used or a dedicated indicator may be sent from the UE or the ATCF to the PCRF, via the P-CSCF. The media reservation may be accepted, even if there may not be enough bandwidth or other resources available in the radio network and even if the GBR (guaranteed bit rate) bearers are not supported, (e.g., when UE is currently in a GERAN/UTRAN). At this point, the reserved media resources may be held and no media may be sent over the reserved bearers. In this regard, the operation 121 and 122, where the INVITE message is sent and the response is provided with the codec selection may be referred to as the codec pre- negotiation phase.

[0029] At 123, the UE may initiate or receive a CS call. At this point, both the

UE and the ATCF are aware of the codec to be used after the rSRVCC procedure and the port number to be used for RTP. Additionally, the reservation of the media resources was previously performed, and therefore there is no need to perform the reservation from ATCF to P-CSCF to PCRF again. Also, there is no need to send an INVITE from the UE to the ATCF at this point in the procedure, unlike some other procedures, because the negotiation and media reservation was previously completed at the codec pre-negotiation phase described above. An additional benefit of implementing some example

embodiments involving a type of codec pre-negotiation, is that the subsequent rSRVCC procedure may be more quickly completed because of an associated reduction in a number of messages required during the rSRVCC procedure as further explained below.

[0030] Accordingly, subsequent to performing the rSRVCC procedure at 124, the

ATCF may indicate to the PCRF (via P-CSCF) that the pre-negotiated media resources are now available to use, thereby activating the media flow for the QCI=1 bearer. The

QCI=1 bearer may then handed over to LTE. In some example embodiments, if the pre- negotiated codec is different from what ATCF has negotiated towards the remote end, the ATCF/ATGW may begin to perform transcoding accordingly.

[0031] An example rSRVCC procedure that may be performed at 124 is further described below with respect to FIG. 2. In this regard, FIG. 2 is a signaling diagram for an rSRVCC procedure according to various example embodiments that operates with a network including each of the following which may be embodied as or components of communications devices: UE 150, BSC/RNC (Base Station Controller/Radio Network Controller) 151, NB/eNB (Node B/evolved Node B) 152, MSC (Mobile Switching Center) Server 153, source SGSN (Serving General Packet Radio Service Support Node) 154, SGW/PGW (Serving Gateway/Packet Data Network Gateway) 155, PCRF 156, ATCF 157, P-CSCF 158, and target MME (Mobility Management Entity) 159.

[0032] To begin the example rSRVCC procedure, at 161 , the BSC/RNC 151 may send an HO required message to the MSC Server 153, which may include an indication that the HO required message is for SRVCC. Since, according to some example embodiments, the PS bearers may be suspended, the HO required message need be not sent by the RAN (Radio Access Network) to the source SGSN 154. At 162, the MSC Server 153 may send an SRVCC CS to PS HO command to the Source SGSN 154. It is noteworthy that since bearer resources have been reserved prior to the rSRVCC procedure, there is no need perform bearer reservation for QCI=1 media bearer and the associated messaging at this point. At 163, the source SGSN 154 may send a relocation request to the target SGSN/MME 159. In turn, the target SGSN/MME 159 may allocate resources in UTRAN/E-UTRAN at 164, and may send a relocation response to the source SGSN at 165. Accordingly, an SRVCC CS to PS HO response may be returned from the source SGSN 154 to the MSC Server 153 at 166. The MSC Server 153 may then send an HO required acknowledgement to the RAN, and the RAN may send an HO command to the UE 150 indicating a CS to PS handover at 167. Again here, it is noteworthy that a codec was selected prior to the rSRVCC procedure and, according to various example embodiments, there is no need to include an indication of the selected codec in the HO command to the UE 150.

[0033] At 168, the MSC Server 153 may send a re-INVITE to the ATCF 157 to trigger the ATCF/ATGW 157 to switch the media path to the IP address and/or port of the UE 150 on the target access. An MGW (Media Gateway) providing media content may, for a threshold period of time, send media both on the source access leg and the new target access leg to minimize the interruption delay further. Additionally, because the QCI=1 media bearer was reserved and held during the pre-negotiation phase, the bearer may continue to be preserved. Once the ATCF 157 receives an indication, or otherwise determines, that the rSRVCC procedure has been successfully completed, the ATCF 157 may activate the media bearer via the PCRF 156. Depending on the selected codec at the pre-negotiation phase, the ATCF 157 may begin to transcode the media streams between the UE 150 and the remote end. The transition by the UE 150 may then be complete.

[0034] With respect to the selection of the codec, according to some example embodiments, the codec negotiation may performed between the MSC Server 153 and the remote end (e.g., an IMS UE or a PSTN (Public Switched Telephone Network) gateway). In this regard, the ATCF 157 may be transparent to the codec selection, except that the ATCF 157 needs to be capable of supporting the selected coding in case transcoding after the rSRVCC is needed.

[0035] In this regard, assume that the MSC Server 153 has selected the G.711 codec towards the remote end in the PSTN. In some instances, 3GPP IMS UEs may support only AMR-NB (Adaptive Multi-Rate Narrowband) codecs, and conditionally the AMR-WB (Adaptive Multi-Rate Wideband) codecs, but not G.711 codecs. Accordingly, in some example embodiments, the ATFC 157 may need to begin performing transcoding after the rSRVCC, regardless of whether the codec was selected prior to or after the CS call.

[0036] On the other hand, assume the MSC Server 153 has selected AMR-WB based on the negotiation with the remote end. If the UE 150 does not support AMR-WB, but uses AMR-NB instead, transcoding may again be required in ATCF 157 after the rSRVCC, regardless of when the codec negotiation transpired. If the UE 150 supports

AMR-WB, which is selected as a final codec, again, the timing of the codec selection does not impact the outcome. Similarly, if MSC Server 157 selects AMR-NB, and the UE 150 only supports AMR-NB, there is no impact on the outcome due to the earlier selection of the codec. However, in some example embodiments, if the MSC Server 153 selects AMR-NB, but the UE supports also AMR-WB, the outcome may be impacted. When the codec is selected after the CS call, AMR-NB may be selected, thereby requiring no transcoding in ATCF 157 after the rSRVCC. However, when the codec is selected prior to the CS call, AMR-WB may be selected (assuming that the ATCF 157 supports AMR- WB) and therefore transcoding may be required after rSRVCC.

[0037] As such, the earlier selection of a codec may, according to some example embodiments, infrequently cause relatively more transcoding. However, earlier selection of the codec, according to various example embodiments, may facilitate a faster rSRVCC transfer procedure, may require less interfaces and messaging, and/or may have less dependencies between different layers in the UE, since the radio layer does not need to indicate the final codec received in the HO command to the IMS layer.

[0038] The description provided above and generally herein illustrates example methods, example apparatuses, and example computer program products for implementing communications session continuity. FIG. 3 depicts an example apparatus that may be configured to perform the functionalities of the various network entities described with respect to FIGs. la, lb, and 2, and as otherwise described herein. In this regard, the apparatus 500 of FIG. 3 may be configured to perform the functionality described with respect to, for example, the UE 150 or the functionality of the ATCF 157. FIG. 4 depicts a more detailed embodiment of an example apparatus of user equipment in the form of a mobile terminal, which may be configured to perform at least the functionality of the UE 150 described above and otherwise herein. Further, based on the configuration of the apparatus 500, the apparatus 500 may be configured to perform the example methods depicted in FIGs. 5 and 6, and the operations otherwise described herein.

[0039] Referring now to FIG. 3, an example embodiment of the present invention is depicted as apparatus 500. The UE 150 may be one example embodiment of apparatus 500. Apparatus 500 may, be embodied as, or included as a component of, a

communications device with wired and/or wireless communications capabilities. In some example embodiments, the apparatus 500 may be part of a communications device, such as a stationary or a mobile communications terminal. As a mobile device, the apparatus 500 may be a mobile and/or wireless communications node such as, for example, a mobile and/or wireless server, computer, access point, communications switching device, handheld wireless device (e.g., telephone, portable digital assistant (PDA), mobile television, gaming device, camera, video recorder, audio/video player, radio, digital book reader, and/or a global positioning system (GPS) device), any combination of the aforementioned, or the like. The apparatus may alternatively be embodied as a network entity, such as a server, a computer, a router, a gateway, a hub, or the like. In this regard, the apparatus 500 may be embodied as, or be a component of, one or more of the

BSC/R C 151, the NB/eNB 152, the MSC Server 153, the SGSN 154, the SGW/PGW 155, the PCRF 156, the ATCF 157, the P-CSCF 158, and/or the MME 159. Regardless of the type of communications device, apparatus 500 may also include computing capabilities.

[0040] FIG. 3 illustrates a functional block diagram of example components of the apparatus 500. The example apparatus 500 includes or is otherwise in communication with a processor 505, a memory device 510, an Input/Output (I/O) interface 506, a communications interface 515, and a handover manager 540. The processor 505 may be embodied as various means for implementing the various functionalities of example embodiments of the present invention including, for example, a microprocessor, a coprocessor, a controller, a special-purpose integrated circuit such as, for example, an ASIC (application specific integrated circuit), an FPGA (field programmable gate array), or a hardware accelerator, processing circuitry or the like. According to one example embodiment, processor 505 may be representative of a plurality of processors, or one or more multiple core processors, operating in concert. Further, the processor 505 may be comprised of a plurality of transistors, logic gates, a clock (e.g., oscillator), other circuitry, and the like to facilitate performance of the functionality described herein. The processor 505 may, but need not, include one or more accompanying digital signal processors. In some example embodiments, the processor 505 is configured to execute instructions stored in the memory device 510 or instructions otherwise accessible to the processor 505. The processor 505 may be configured to operate such that the processor causes the apparatus 500 to perform various functionalities described herein.

[0041] Whether configured as hardware or via instructions stored on a computer- readable storage medium, or by a combination thereof, the processor 505 may be an entity and means capable of performing operations according to embodiments of the present invention while configured accordingly. Thus, in example embodiments where the processor 505 is embodied as, or is part of, an ASIC, FPGA, or the like, the processor 505 is specifically configured hardware for conducting the operations described herein.

Alternatively, in example embodiments where the processor 505 is embodied as an executor of instructions stored on a computer-readable storage medium, the instructions specifically configure the processor 505 to perform the algorithms and operations described herein. In some example embodiments, the processor 505 is a processor of a specific device (e.g., a communications server or mobile terminal) configured for employing example embodiments of the present invention by further configuration of the processor 505 via executed instructions for performing the algorithms, methods, and operations described herein.

[0042] The memory device 510 may be one or more tangible and/or non-transitory computer-readable storage media that may include volatile and/or non-volatile memory. In some example embodiments, the memory device 510 includes Random Access Memory (RAM) including dynamic and/or static RAM, on-chip or off-chip cache memory, and/or the like. Further, memory device 510 may include non- volatile memory, which may be embedded and/or removable, and may include, for example, read-only memory, flash memory, magnetic storage devices (e.g., hard disks, floppy disk drives, magnetic tape, etc.), optical disc drives and/or media, non-volatile random access memory (NVRAM), and/or the like. Memory device 510 may include a cache area for temporary storage of data. In this regard, some or all of memory device 510 may be included within the processor 505. In some example embodiments, the memory device 510 may be in communication with the processor 505 and/or other components via a shared bus.

[0043] Further, the memory device 510 may be configured to store information, data, applications, computer-readable program code instructions, and/or the like for enabling the processor 505 and the example apparatus 500 to carry out various functions in accordance with example embodiments of the present invention described herein. For example, the memory device 510 could be configured to buffer input data for processing by the processor 505. Additionally, or alternatively, the memory device 510 may be configured to store instructions for execution by the processor 505.

[0044] The I/O interface 506 may be any device, circuitry, or means embodied in hardware, software, or a combination of hardware and software that is configured to interface the processor 505 with other circuitry or devices, such as the communications interface 515. In some example embodiments, the I/O interface may embody or be in communication with a bus that is shared by multiple components. In some example embodiments, the processor 505 may interface with the memory 510 via the I/O interface

506. The I/O interface 506 may be configured to convert signals and data into a form that may be interpreted by the processor 505. The I/O interface 506 may also perform buffering of inputs and outputs to support the operation of the processor 505. According to some example embodiments, the processor 505 and the I/O interface 506 may be combined onto a single chip or integrated circuit configured to perform, or cause the apparatus 500 to perform, various functionalities of the present invention.

[0045] In some embodiments, the apparatus 500 or some of the components of apparatus 500 (e.g., the processor 505 and the memory device) may be embodied as a chip or chip set. In other words, the apparatus 500 may comprise one or more physical packages (e.g., chips) including materials, components and/or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, conservation of size, and/or limitation of electrical interaction for component circuitry included thereon. The apparatus 500 may therefore, in some cases, be configured to implement embodiments of the present invention on a single chip or as a single "system on a chip." As such, in some cases, a chip or chipset may constitute means for performing the functionalities described herein and with respect to the processor 505.

[0046] The communication interface 515 may be any device or means embodied in hardware, a computer program product, or a combination of hardware and a computer program product that is configured to receive and/or transmit data from/to a network 520 and/or any other device or module in communication with the example apparatus 500. The communications interface may be configured to communicate information via any type of wired or wireless connection, and via any type of communications protocol, such as a communications protocol that supports cellular communications. For example, the communications interface may be configured to support communications with a

UTRAN/GERAN or an E-UTRAN/HSPA. According to some example embodiments, the communications interface may include a single radio that is capable of being configured to communication with the various networks and communications techniques describe herein. According to various example embodiments, the communication interface 515 may be configured to support the transmission and reception of

communications in a variety of networks including, but not limited to Internet Protocol- based networks (e.g., the Internet), cellular networks, or the like. Further, the

communications interface 515 may be configured to support device-to-device

communications. Processor 505 may also be configured to facilitate communications via the communications interface 515 by, for example, controlling hardware included within the communications interface 515. In this regard, the communication interface 515 may include, for example, communications driver circuitry (e.g., circuitry that supports wired communications via, for example, fiber optic connections), one or more antennas, a transmitter, a receiver, a transceiver and/or supporting hardware, including, for example, a processor for enabling communications. Via the communication interface 515, the example apparatus 500 may communicate with various other network entities in a device- to-device fashion and/or via indirect communications via a base station, access point, server, gateway, router, or the like.

[0047] The user interface 525 which may be a component of a user equipment embodiment of apparatus 500, may be in communication with the processor 505 to receive user input via the user interface 525 and/or to present output to a user as, for example, audible, visual, mechanical, or other output indications. The user interface 525 may include, for example, a keyboard, a mouse, a joystick, a display (e.g., a touch screen display), a microphone, a speaker, or other input/output mechanisms. Further, the processor 505 may comprise, or be in communication with, user interface circuitry configured to control at least some functions of one or more elements of the user interface. The processor 505 and/or user interface circuitry may be configured to control one or more functions of one or more elements of the user interface through computer program instructions (e.g., software and/or firmware) stored on a memory accessible to the processor 505 (e.g., volatile memory, non-volatile memory, and/or the like). The user interface 525 may also be configured to support the implementation of haptic feedback. In this regard, the user interface 525, as controlled by processor 205, may include a vibra, a piezo, and/or an audio device configured for haptic feedback as described herein. In some example embodiments, the user interface circuitry is configured to facilitate user control of at least some functions of the apparatus 500 through the use of a display and configured to respond to user inputs. The processor 505 may also comprise, or be in communication with, display circuitry configured to display at least a portion of a user interface, the display and the display circuitry configured to facilitate user control of at least some functions of the apparatus 500.

[0048] The handover manager 540 of example apparatus 500 may be any means or device embodied, partially or wholly, in hardware, a computer program product, or a combination of hardware and a computer program product, such as processor 505 implementing stored instructions to configure the example apparatus 500, memory device 510 storing executable program code instructions configured to carry out the functions described herein, or a hardware configured processor 505 that is configured to carry out the functions of the handover manager 540 as described herein. In an example embodiment, the processor 505 includes, or controls, the handover manager 540. The handover manager 540 may be, partially or wholly, embodied as processors similar to, but separate from processor 505. In this regard, the handover manager 540 may be in communication with the processor 505. In various example embodiments, the handover manager 540 may, partially or wholly, reside on differing apparatuses such that some or all of the functionality of the handover manager 540 may be performed by a first apparatus, and the remainder of the functionality of the handover manager 540 may be performed by one or more other apparatuses.

[0049] Further, the apparatus 500 and the processor 505 may be configured to perform the following functionality via handover manager 540. In this regard, the handover manager 540 may be configured to cause or direct means such as the processor 505 and/or the apparatus 500 to perform various functionalities, such as those described with respect to FIGs. la, lb, 2, 5, and 6, and as generally described herein.

[0050] For example, with reference to FIG. 5 and where the apparatus 500 is configured as a user equipment device, the handover manager 540 may be configured to cause a message to be sent, from a user equipment, requesting a codec at 600. The user equipment (e.g., embodied as, or embodied as a component of, the apparatus 500) may be connected to a circuit switched access network. The handover manager 540 may also be configured to receive a response including at least an indication of the codec at 610, and cause bearer resources to be reserved at 620, where the codec to be used for

communications via the bearer to be established. The handover manager 540 may also be configured to cause a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources at 630.

[0051] According to some example embodiments, the handover manager 540 may be additionally configured to negotiate a port number of the user equipment for use in establishing the bearer. According to some example embodiments, the handover manager 540 may cause the user equipment to attach to the circuit switched access network, and cause performance of an internet protocol multimedia subsystem registration of the user equipment with respect to the packet switched network. Additionally or alternatively, the handover manager 540 may be configured to cause the message to be sent, which may include causing the message to be sent as a session initiation protocol message (e.g., an INVITE message). Additionally or alternatively, the handover manager 540 may be configured to cause the message to be sent to a uniform resource identifier of an access control transfer function. Additionally, the handover operation may be from the circuit switched access network to the packet switched access network, where the circuit switched access network is, for example, an E-UTRAN/HSPA and the packet switched access network is, for example, a UTRA /GERA . Further, according to various example embodiments, the handover may be performed using a single radio of the user equipment.

[0052] For example, with reference to FIG. 6 and where the apparatus 500 is configured as a network entity device (e.g., the ATCF 157), the handover manager 540 may be configured to receive a message from a user equipment, perhaps via other network elements, requesting a codec at 700, where the user equipment is connected to a circuit switched access network. The handover manager 540 may also be configured to cause a response to be provided to the user equipment including the codec or an indication of the codec at 710, and causing bearer resources to be reserved at 720, where the codec is to be used for communications via the bearer to be established. The handover manager 540 may also be configured to cause a handover operation for the user equipment from the circuit switched access network to a packet switched access network, subsequent to reservation of the bearer resources.

[0053] According to some example embodiments, the handover manager 540 may additionally be configured to negotiate a port number of the user equipment for use in establishing the bearer. Additionally or alternatively, the handover manager 540 may be configured to receive the message as a session initiation protocol message (e.g., an INVITE message). Additionally or alternatively, the handover manager 540 may be configured to cause a response to be provided in the form of a session description protocol answer. Additionally or alternatively, the handover manager 540 may be configured to receive the message with a uniform resource identifier of an access control transfer function. Additionally, the handover operation may be from the circuit switched access network to the packet switched access network, where the circuit switched access network is an, for example, E-UTRAN/HSPA and the packet switched access network is a, for example, UTRAN/GERAN. Further, according to various example embodiments, the handover may be performed using a single radio of the user equipment.

[0054] Referring now to FIG. 4, a more specific example apparatus in accordance with some embodiments of the present invention is provided. The example apparatus of FIG. 4 is a mobile terminal 10 configured to communicate within a wireless network, such as a cellular communications network. The mobile terminal 10 may be configured to perform the functionality of the UE 150 or apparatus 500 as described herein. More specifically, the mobile terminal 10 may be caused to perform the functionality described with respect to FIGs. la, lb, 2, 5, and 6 via the processor 20. In this regard, according to some example embodiments, the processor 20 may be configured to perform the functionality described with respect to the handover manager 540. Processor 20 may be an integrated circuit or chip configured similar to the processor 505 together with, for example, the I/O interface 506. Further, volatile memory 40 and non-volatile memory 42 may be configured to support the operation of the processor 20 as computer readable storage media.

[0055] The mobile terminal 10 may also include an antenna 12, a transmitter 14, and a receiver 16, which may be included as parts of a communications interface of the mobile terminal 10. The speaker 24, the microphone 26, displays 28 (which may be touch screen displays), and the keypad 30 may be included as parts of a user interface.

[0056] FIGs. la, lb, 2, 5, and 6 illustrate flowcharts of example systems, methods, and/or computer program products according to some example embodiments of the invention. It will be understood that each operation of the fiowcharts, and/or

combinations of operations in the fiowcharts, can be implemented by various means. Means for implementing the operations of the fiowcharts, combinations of the operations in the flowchart, or other functionality of example embodiments of the present invention described herein may include hardware, and/or a computer program product including a computer-readable storage medium (as opposed to a computer-readable transmission medium which describes a propagating signal) having one or more computer program code instructions, program instructions, or executable computer-readable program code instructions stored therein. In this regard, program code instructions for performing the operations and functions of FIGs. la, lb, 2, 5, and 6 and otherwise described herein may be stored on a memory device, such as memory device 510, volatile memory 40, or volatile memory 42, of an example apparatus, such as example apparatus 500 or mobile terminal 10, and executed by a processor, such as the processor 505 or processor 20. As will be appreciated, any such program code instructions may be loaded onto a computer or other programmable apparatus (e.g., processor 505, memory device 510, or the like) from a computer-readable storage medium to produce a particular machine, such that the particular machine becomes a means for implementing the functions specified in the flowcharts' operations. These program code instructions may also be stored in a computer-readable storage medium that can direct a computer, a processor, or other programmable apparatus to function in a particular manner to thereby generate a particular machine or particular article of manufacture. The instructions stored in the computer- readable storage medium may produce an article of manufacture, where the article of manufacture becomes a means for implementing the functions specified in the flowcharts' operations. The program code instructions may be retrieved from a computer-readable storage medium and loaded into a computer, processor, or other programmable apparatus to configure the computer, processor, or other programmable apparatus to execute operations to be performed on or by the computer, processor, or other programmable apparatus. Retrieval, loading, and execution of the program code instructions may be performed sequentially such that one instruction is retrieved, loaded, and executed at a time. In some example embodiments, retrieval, loading and/or execution may be performed in parallel such that multiple instructions are retrieved, loaded, and/or executed together. Execution of the program code instructions may produce a computer- implemented process such that the instructions executed by the computer, processor, or other programmable apparatus provide operations for implementing the functions specified in the flowcharts' operations.

[0057] Accordingly, execution of instructions associated with the operations of the flowchart by a processor, or storage of instructions associated with the blocks or operations of the flowcharts in a computer-readable storage medium, support combinations of operations for performing the specified functions. It will also be understood that one or more operations of the flowcharts, and combinations of blocks or operations in the flowcharts, may be implemented by special purpose hardware-based computer systems and/or processors which perform the specified functions, or combinations of special purpose hardware and program code instructions.

[0058] Based on the forgoing description, additional example embodiments may be defined and described in the form of methods, apparatuses, systems, computer programs, computer program products, and the like. For example, one embodiment of an example apparatus may comprise at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, direct or cause the apparatus at least to perform the example methods described below and/or those otherwise described herein. Further, another example embodiment may be a computer program product comprising a non-transitory computer readable medium having instructions stored thereon, the instructions being configured to cause and apparatus to perform the example methods described below and/or those otherwise described herein when executed. Another example apparatus can also be defined as including means, such as a processor, for implementing the operations of the example methods described below and/or those otherwise described herein. [0059] An example method of the present invention may include causing a message to be sent, from a user equipment, requesting a codec. The user equipment may be connected to a circuit switched access network. The example method may also include receiving a response including at least an indication of the codec, and causing bearer resources to be reserved, where the codec to be used for communications via the bearer to be established. The method may also include causing a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

[0060] According to some example embodiments, the example method may additionally include negotiating a port number of the user equipment for use in establishing the bearer. According to some example embodiments, the example method may include causing the user equipment to attach to the circuit switched access network, and causing performance of an internet protocol multimedia subsystem registration of the user equipment. Additionally or alternatively, causing the message to be sent includes causing the message to be sent as a session initiation protocol message (e.g., an INVITE message). Additionally or alternatively, causing the message to be sent includes causing the message to be sent to a uniform resource identifier of an access control transfer function.

Additionally, the handover operation may be from the circuit switched access network to the packet switched access network, where the circuit switched access network is an E- UTRAN/HSPA and the packet switched access network is a UTRAN/GERAN. Further, according to various example embodiments, the handover may be performed using a single radio of the user equipment.

[0061] Another example method includes receiving a message from a user equipment requesting a codec, where the user equipment is connected to a circuit switched access network. The example method may also include causing a response to be provided to the user equipment including the codec or an indication of the codec, and causing bearer resources to be reserved, where the codec is to be used for communications via the bearer to be established. The example method may also include causing a handover operation for the user equipment from the circuit switched access network to a packet switched access network, subsequent to reservation of the bearer resources.

[0062] According to some example embodiments, the example method may additionally include negotiating a port number of the user equipment for use in establishing the bearer. Additionally or alternatively, receiving the message as a session initiation protocol message (e.g., an INVITE message). Additionally or alternatively, causing a response to be provided may include causing the response to be provided in the form of a session description protocol answer. Additionally or alternatively, receiving the message includes receiving the message with a uniform resource identifier of an access control transfer function. Additionally, the handover operation may be from the circuit switched access network to the packet switched access network, where the circuit switched access network is an E-UTRAN/HSPA and the packet switched access network is a

UTPvAN/GEPvAN. Further, according to various example embodiments, the handover may be performed using a single radio of the user equipment.

[0063] Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Moreover, although the foregoing descriptions and the associated drawings describe example embodiments in the context of certain example combinations of elements and/or functions, it should be appreciated that different combinations of elements and/or functions may be provided by alternative embodiments without departing from the scope of the appended claims. In this regard, for example, different combinations of elements and/or functions other than those explicitly described above are also contemplated as may be set forth in some of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

What is claimed is:

1. A method comprising:

causing a message to be sent, from a user equipment, requesting a codec, the user equipment being connected to a circuit switched access network;

receiving a response including at least an indication of the codec;

causing bearer resources to be reserved, wherein the codec is to be used for communications via a bearer that is established with the bearer resources; and

causing a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

2. The method of claim 1, further comprising causing a port number of the user equipment to be negotiated for use in establishing the bearer.

3. The method of any one of claims 1 or 2, further comprising:

causing the user equipment to attach to the circuit switched access network; and causing performance of an internet protocol multimedia subsystem registration of the user equipment.

4. The method of any one of claims 1 through 3, wherein causing the message to be sent includes causing the message to be sent as a session initiation protocol message.

5. The method of claim 4 wherein causing the message to be sent includes causing the message to be sent as the session initiation protocol message, the session initiation protocol message being an INVITE message.

6. The method of any one of claims 1 through 5, wherein causing the message to be sent includes causing the message to be sent to a uniform resource identifier of an access control transfer function.

7. The method of any one of claims 1 through 6, wherein causing the handover operation includes causing the handover operation to be from the circuit switched access network to the packet switched access network, the circuit switched access network being an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network being a UTRAN/GERAN

(Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

8. The method of any one of claims 1 through 7, wherein causing the handover operation includes causing the handover operation to be performed using a single radio of the user equipment.

9. A computer program that, when executed, directs an apparatus to perform the method of any one of claims 1 through 8.

10. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, direct the apparatus at least to:

cause a message to be sent, from a user equipment, requesting a codec, the user equipment being connected to a circuit switched access network;

receive a response including at least an indication of the codec;

cause bearer resources to be reserved, wherein the codec is to be used for communications via a bearer that is established with the bearer resources; and

cause a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

11. The apparatus of claim 10, wherein the apparatus is further directed to cause a port number of the user equipment to be negotiated for use in establishing the bearer.

12. The apparatus of any one of claims 10 or 11, wherein the apparatus is further directed to:

cause the user equipment to attach to the circuit switched access network; and cause performance of an internet protocol multimedia subsystem registration of the user equipment.

13. The apparatus of any one of claims 10 through 12, wherein the apparatus directed to cause the message to be sent includes being directed to cause the message to be sent as a session initiation protocol message.

14. The apparatus of claim 13 wherein the apparatus directed to cause the message to be sent includes being directed to cause the message to be sent as the session initiation protocol message, the session initiation protocol message being an INVITE message.

15. The apparatus of any one of claims 10 through 14, wherein the apparatus directed to cause the message to be sent includes being directed to cause the message to be sent to a uniform resource identifier of an access control transfer function.

16. The apparatus of any one of claims 10 through 15, wherein the apparatus directed to cause the handover operation includes being directed to cause the handover operation to be from the circuit switched access network to the packet switched access network, the circuit switched access network being an E-UTRAN/HSPA (Evolved

Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network being a UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

17. The apparatus of any one of claims 10 through 16, wherein the apparatus directed to cause the handover operation includes being directed to cause the handover operation to be performed using a single radio of the user equipment.

18. The apparatus of any one of claims 10 through 17, wherein the apparatus further comprises communications interface hardware configured to transmit the message requesting the codec.

19. The apparatus of claim 18, wherein the apparatus is a mobile device.

20. An apparatus comprising:

means for causing a message to be sent, from a user equipment, requesting a codec, the user equipment being connected to a circuit switched access network;

means for receiving a response including at least an indication of the codec;

means for causing bearer resources to be reserved, wherein the codec is to be used for communications via a bearer that is established with the bearer resources; and means for causing a handover operation from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

21. The apparatus of claim 20, further comprising means for causing a port number of the user equipment to be negotiated for use in establishing the bearer.

22. The apparatus of any one of claims 20 or 21, further comprising:

means for causing the user equipment to attach to the circuit switched access network; and

means for causing performance of an internet protocol multimedia subsystem registration of the user equipment.

23. The apparatus of any one of claims 20 through 22, wherein the means for causing the message to be sent includes means for causing the message to be sent as a session initiation protocol message.

24. The apparatus of claim 23 wherein the means for causing the message to be sent includes means for causing the message to be sent as the session initiation protocol message, the session initiation protocol message being an INVITE message.

25. The apparatus of any one of claims 20 through 24, wherein the means for causing the message to be sent includes causing the message to be sent to a uniform resource identifier of an access control transfer function.

26. The apparatus of any one of claims 20 through 25, wherein the means for causing the handover operation includes means for causing the handover operation to be from the circuit switched access network to the packet switched access network, the circuit switched access network being an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network being a UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

27. The apparatus of any one of claims 20 through 26, wherein the means for causing the handover operation includes means for causing the handover operation to be performed using a single radio of the user equipment.

28. A computer program product comprising at least one computer-readable medium having instructions stored thereon, the instructions being configured to, when executed, direct an apparatus to at least:

receive a response including at least an indication of the codec;

29. The computer program product of claim 28, wherein the instructions are further configured to direct the apparatus to cause a port number of the user equipment to be negotiated for use in establishing the bearer.

30. The computer program product of any one of claims 28 or 29, wherein the instructions are further configured to direct the apparatus to:

31. The computer program product of any one of claims 28 through 30, wherein the instructions configured to direct the apparatus to cause the message to be sent include being configured to direct the apparatus to cause the message to be sent as a session initiation protocol message.

32. The computer program product of claim 28, wherein the instructions configured to direct the apparatus to cause the message to be sent include being configured to direct the apparatus to cause the message to be sent as the session initiation protocol message, the session initiation protocol message being an INVITE message.

33. The computer program product of any one of claims 28 through 32, wherein the instructions configured to direct the apparatus to cause the message to be sent include being configured to direct the apparatus to cause the message to be sent to a uniform resource identifier of an access control transfer function.

34. The computer program product of any one of claims 28 through 33, wherein the instructions configured to direct the apparatus to cause the handover operation include being configured to direct the apparatus to cause the handover operation to be from the circuit switched access network to the packet switched access network, the circuit switched access network being an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network being a UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

35. The computer program product of any one of claims 28 through 34, wherein the instructions configured to direct the apparatus to cause the handover operation include being configured to direct the apparatus to cause the handover operation to be performed using a single radio of the user equipment.

36. A method comprising:

receiving a message from a user equipment requesting a codec, wherein the user equipment is connected to a circuit switched access network;

causing a response to be provided to the user equipment including the codec or an indication of the codec;

causing bearer resources to be reserved, wherein the codec is to be used for communications via the bearer that is established using the bearer resources; and

causing a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

37. The method of claim 36 further comprising causing a port number of the user equipment to be negotiated for use in establishing the bearer.

38. The method of any one of claim 36 or 37, wherein receiving the message includes receiving the message as a session initiation protocol message.

39. The method of claim 38, wherein receiving the message includes receiving the message as the session initiation protocol message, the session initiation protocol message being an INVITE message.

40. The method of any one of claims 36 through 39, wherein causing a response to be provided includes causing the response to be provided in the form of a session description protocol answer.

41. The method of any one of claims 36 through 40, wherein receiving the message includes receiving the message with a uniform resource identifier of an access control transfer function.

42. The method of any one of claims 36 through 41, wherein causing the handover operation includes causing the handover operation to be from the circuit switched access network to the packet switched access network, wherein the circuit switched access network is an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access

Network/High Speed Packet Access) and the packet switched access network is a

UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

43. The method of any one of claims 36 through 42, wherein causing the handover operation includes causing the handover operation to be performed with a single radio of the user equipment.

44. A computer program that, when executed, directs an apparatus to perform the method of any one of claims 36 through 43.

45. An apparatus comprising at least one processor and at least one memory including computer program code, the at least one memory and the computer program code configured to, with the at least one processor, direct the apparatus at least to: receive a message from a user equipment requesting a codec, wherein the user equipment is connected to a circuit switched access network;

cause a response to be provided to the user equipment including the codec or an indication of the codec;

cause bearer resources to be reserved, wherein the codec is to be used for communications via the bearer that is established using the bearer resources; and

cause a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

46. The apparatus of claim 45, wherein the apparatus is further directed to cause a port number of the user equipment to be negotiated for use in establishing the bearer.

47. The apparatus of any one of claim 45 or 46, wherein the apparatus directed to receive the message includes being directed to receive the message as a session initiation protocol message.

48. The apparatus of claim 47, wherein the apparatus directed to receive the message includes being directed to receive the message as the session initiation protocol message, the session initiation protocol message being an INVITE message.

49. The apparatus of any one of claims 45 through 48, wherein the apparatus directed to cause a response to be provided includes being directed to cause the response to be provided in the form of a session description protocol answer.

50. The apparatus of any one of claims 45 through 49, wherein the apparatus directed to receive the message includes being directed to receive the message with a uniform resource identifier of an access control transfer function.

51. The apparatus of any one of claims 45 through 50, wherein the apparatus directed to cause the handover operation includes being directed to cause the handover operation to be from the circuit switched access network to the packet switched access network, wherein the circuit switched access network is an E-UTRAN/HSPA (Evolved

Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network is a UTRA /GERA (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

52. The apparatus of any one of claims 45 through 51 , wherein the apparatus directed to cause the handover operation includes being directed to cause the handover operation to be performed with a single radio of the user equipment.

53. The apparatus of any one of claims 45 through 52, wherein the apparatus further comprises communications interface hardware configured to receive the message requesting the codec.

54. The apparatus of claim 53, wherein the apparatus is a network device.

55. A apparatus comprising :

means for receiving a message from a user equipment requesting a codec, wherein the user equipment is connected to a circuit switched access network;

means for causing a response to be provided to the user equipment including the codec or an indication of the codec;

means for causing bearer resources to be reserved, wherein the codec is to be used for communications via the bearer that is established using the bearer resources; and

means for causing a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

56. The apparatus of claim 55 further comprising means for causing a port number of the user equipment to be negotiated for use in establishing the bearer.

57. The apparatus of any one of claim 55 or 56, wherein the means for receiving the message includes means for receiving the message as a session initiation protocol message.

58. The apparatus of claim 57, wherein the means for receiving the message includes means for receiving the message as the session initiation protocol message, the session initiation protocol message being an INVITE message.

59. The apparatus of any one of claims 55 through 58, wherein the means for causing a response to be provided includes means for causing the response to be provided in the form of a session description protocol answer.

60. The apparatus of any one of claims 55 through 59, wherein the means for receiving the message includes means for receiving the message with a uniform resource identifier of an access control transfer function.

61. The apparatus of any one of claims 55 through 60, wherein the means for causing the handover operation includes means for causing the handover operation to be from the circuit switched access network to the packet switched access network, wherein the circuit switched access network is an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network is a UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

62. The apparatus of any one of claims 55 through 61, wherein the means for causing the handover operation includes means for causing the handover operation to be performed with a single radio of the user equipment.

63. A computer program product comprising at least one computer-readable medium having instructions stored thereon, the instructions being configured to, when executed, direct an apparatus to at least:

receive a message from a user equipment requesting a codec, wherein the user equipment is connected to a circuit switched access network;

cause bearer resources to be reserved, wherein the codec is to be used for communications via the bearer that is established using the bearer resources; and cause a handover operation of the user equipment from the circuit switched access network to a packet switched access network subsequent to reservation of the bearer resources.

64. The apparatus of claim 63, wherein the instructions are further configured to direct the apparatus to cause a port number of the user equipment to be negotiated for use in establishing the bearer.

65. The apparatus of any one of claim 63 or 64, wherein the instructions configured to direct the apparatus to receive the message include being configured to direct the apparatus to receive the message as a session initiation protocol message.

66. The apparatus of claim 65, wherein the instructions configured to direct the apparatus to receive the message include being configured to direct the apparatus to receive the message as the session initiation protocol message, the session initiation protocol message being an INVITE message.

67. The apparatus of any one of claims 63 through 66, wherein the instructions configured to direct the apparatus to cause a response to be provided include being configured to direct the apparatus to cause the response to be provided in the form of a session description protocol answer.

68. The apparatus of any one of claims 63 through 67, wherein the instructions configured to direct the apparatus to receive the message include being configured to direct the apparatus to receive the message with a uniform resource identifier of an access control transfer function.

69. The apparatus of any one of claims 63 through 68, wherein the instructions configured to direct the apparatus to cause the handover operation include being configured to direct the apparatus to cause the handover operation to be from the circuit switched access network to the packet switched access network, wherein the circuit switched access network is an E-UTRAN/HSPA (Evolved Universal Terrestrial Radio Access Network/High Speed Packet Access) and the packet switched access network is a UTRAN/GERAN (Universal Terrestrial Radio Access Network/Global System for Mobile Communications with Enhanced data rates Radio Access Network).

70. The apparatus of any one of claims 63 through 69, wherein the instructions configured to direct the apparatus to cause the handover operation include being configured to direct the apparatus to cause the handover operation to be performed with a single radio of the user equipment.