WO2018144345A2 - System and method of single radio voice call continuity handover reduction - Google Patents

Abstract

Systems and methods of handover are disclosed. The PCRF decodes IMS service information for voice media from a P-CSCF. The IMS service information contains codec information of a UE. The PCRF sets, based on the codec information in the IMS service information, a Maximum Packet Loss Rate for uplink and downlink communications between the UE and an eNB. The PCRF generates a PCC rule for the voice media and encodes the PCC rule for transmission to a PCEF. The PCC rule includes the Maximum Packet Loss Rate for both directions. The codec information indicates which of a high robustness codec or a low robustness codec is being used by the UE. The eNB uses the codec information to determine handover thresholds and whether SRVCC handover is to occur for the UE.

Description

SYSTEM AND METHOD OF SINGLE RADIO VOICE CALL CONTINUITY

HANDOVER REDUCTION

PRIORITY CLAIM

[0001] This application claims the benefit of priority to U.S. Provisional

Patent Application Serial No. 62/453,974, filed February 2, 2017, entitled "SOLUTION TO AVOID OR MINIMIZE THE POSSIBILITY OF SRVCC HO IN POOR RADIO COVERAGE IN EPS," which is incorporated herein by reference in its entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to radio access networks. Some embodiments relate to handover in cellular and wireless local area network (WLAN) networks, including Third Generation Partnership Project Long Term Evolution (3GPP LTE) networks and LTE advanced (LTE-A) networks as well as legacy, 4^th generation (4G) networks and 5^th generation (5G) networks.

BACKGROUND

[0003] The use of 3 GPP LTE systems (including both LTE and LTE-A systems) has increased due to both an increase in the types of devices user equipment (UEs) using network resources as well as the amount of data and bandwidth being used by various applications, such as video streaming, operating on these UEs. LTE networks typically operate in a number of radio frequency (RF) bands licensed to a wireless operator in which base stations (evolved node Bs (eNBs)) and an increasing number and varying type of user equipment (UE) communicate.

[0004] A wide variety of the UEs, such as smart phones and wearable technology, are mobile. Mobile connectivity is, in fact, increasingly important in modern life. However, a number of mobility -related issues have arisen due to the advent of enhanced network and UE capabilities. One such issue to occur is handover from an LTE system to a legacy switched voice system when a UE is engaging in Voice -over-LTE (VoLTE) communications without appreciably affecting the user experience (e.g. missing packets, extensive delays, or dropped calls) for the VoLTE communications.

BRIEF DESCRIPTION OF THE FIGURES

[0005] In the figures, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may represent different instances of similar components. The figures illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document.

[0006] FIG. 1 illustrates an architecture of a system of a network in accordance with some embodiments.

[0007] FIG. 2 illustrates example components of a device in accordance with some embodiments.

[0008] FIG. 3 illustrates example interfaces of baseband circuitry in accordance with some embodiments.

[0009] FIG. 4 is an illustration of a control plane protocol stack in accordance with some embodiments.

[0010] FIG. 5 is an illustration of a user plane protocol stack in accordance with some embodiments.

[0011] FIG. 6 is a block diagram illustrating components, according to some example embodiments.

[0012] FIG. 7 illustrates a handover process in which a container is provisioned to the eNB in accordance with some embodiments.

[0013] FIG. 8 illustrates an eNB-triggered session modification procedure in accordance with some embodiments.

[0014] FIG. 9 illustrates a UE-triggered session modification procedure in accordance with some embodiments.

DETAILED DESCRIPTION

[0015] The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

[0016] FIG. 1 illustrates an architecture of a system 100 of a network in accordance with some embodiments. The system 100 is shown to include a user equipment (UE) 101 and a UE 102. The UEs 101 and 102 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices connectable to one or more cellular networks), but may also comprise any mobile or non- mobile computing device, such as Personal Data Assistants (PDAs), pagers, laptop computers, desktop computers, wireless handsets, or any computing device including a wireless communications interface.

[0017] In some embodiments, any of the UEs 101 and 102 can comprise an Internet of Things (IoT) UE, which can comprise a network access layer designed for low-power IoT applications utilizing short-lived UE connections. An IoT UE can utilize technologies such as machine-to-machine (M2M) or machine-type communications (MTC) for exchanging data with an MTC server or device via a public land mobile network (PLMN), Proximity-Based Service (ProSe) or device-to-device (D2D) communication, sensor networks, or IoT networks. The M2M or MTC exchange of data may be a machine-initiated exchange of data. An IoT network describes interconnecting IoT UEs, which may include uniquely identifiable embedded computing devices (within the Internet infrastructure), with short-lived connections. The IoT UEs may execute background applications (e.g., keep-alive messages, status updates, etc.) to facilitate the connections of the IoT network.

[0018] The UEs 101 and 102 may be configured to connect, e.g., communicatively couple, with a radio access network (RAN) 110 - the RAN 110 may be, for example, an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN), a NextGen RAN (NG RAN), or some other type of RAN. The UEs 101 and 102 utilize connections 103 and 104, respectively, each of which comprises a physical communications interface or layer (discussed in further detail below); in this example, the connections 103 and 104 are illustrated as an air interface to enable communicative coupling, and can be consistent with cellular communications protocols, such as a Global System for Mobile Communications (GSM) protocol, a code-division multiple access (CDMA) network protocol, a Push-to- Talk (PTT) protocol, a PTT over Cellular (POC) protocol, a Universal Mobile Telecommunications System (UMTS) protocol, a 3GPP Long Term Evolution (LTE) protocol, a 5G protocol, a New Radio (NR) protocol, and the like.

[0019] In this embodiment, the UEs 101 and 102 may further directly exchange communication data via a ProSe interface 105. The ProSe interface 105 may alternatively be referred to as a sidelink interface comprising one or more logical channels, including but not limited to a Physical Sidelink Control Channel (PSCCH), a Physical Sidelink Shared Channel (PSSCH), a Physical Sidelink Discovery Channel (PSDCH), and a Physical Sidelink Broadcast Channel (PSBCH).

[0020] The UE 102 is shown to be configured to access an access point (AP) 106 via connection 107. The connection 107 can comprise a local wireless connection, such as a connection consistent with any IEEE 802.11 protocol, wherein the AP 106 would comprise a wireless fidelity (WiFi®) router. In this example, the AP 106 is shown to be connected to the Internet without connecting to the core network of the wireless system (described in further detail below).

[0021] The RAN 110 can include one or more access nodes that enable the connections 103 and 104. These access nodes (ANs) can be referred to as base stations (BSs), NodeBs, evolved NodeBs (eNBs), next Generation NodeBs (gigabit NodeBs - gNBs), RAN nodes, and so forth, and can comprise ground stations (e.g., terrestrial access points) or satellite stations providing coverage within a geographic area (e.g., a cell). The RAN 110 may include one or more RAN nodes for providing macrocells, e.g., macro RAN node 111, and one or more RAN nodes for providing femtocells or picocells (e.g., cells having smaller coverage areas, smaller user capacity, or higher bandwidth compared to macrocells), e.g., low power (LP) RAN node 112.

[0022] Any of the RAN nodes 111 and 112 can terminate the air interface protocol and can be the first point of contact for the UEs 101 and 102. In some embodiments, any of the RAN nodes 111 and 112 can fulfill various logical functions for the RAN 110 including, but not limited to, radio network controller (RNC) functions such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

[0023] In accordance with some embodiments, the UEs 101 and 102 can be configured to communicate using Orthogonal Frequency -Division

Multiplexing (OFDM) communication signals with each other or with any of the RAN nodes 111 and 112 over a multicarrier communication channel in accordance various communication techniques, such as, but not limited to, an Orthogonal Frequency-Division Multiple Access (OFDMA) communication technique (e.g., for downlink communications) or a Single Carrier Frequency Division Multiple Access (SC-FDMA) communication technique (e.g., for uplink and ProSe or sidelink communications), although the scope of the embodiments is not limited in this respect. The OFDM signals can comprise a plurality of orthogonal subcarriers.

[0024] In some embodiments, a downlink resource grid can be used for downlink transmissions from any of the RAN nodes 111 and 112 to the UEs 101 and 102, while uplink transmissions can utilize similar techniques. The grid can be a time-frequency grid, called a resource grid or time -frequency resource grid, which is the physical resource in the downlink in each slot. Such a time- frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid corresponds to one OFDM symbol and one OFDM subcarrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element. Each resource grid comprises a number of resource blocks, which describe the mapping of certain physical channels to resource elements. Each resource block comprises a collection of resource elements; in the frequency domain, this may represent the smallest quantity of resources that currently can be allocated. There are several different physical downlink channels that are conveyed using such resource blocks. [0025] The physical downlink shared channel (PDSCH) may carry user data and higher-layer signaling to the UEs 101 and 102. The physical downlink control channel (PDCCH) may carry information about the transport format and resource allocations related to the PDSCH channel, among other things. It may also inform the UEs 101 and 102 about the transport format, resource allocation, and H-ARQ (Hybrid Automatic Repeat Request) information related to the uplink shared channel. Typically, downlink scheduling (assigning control and shared channel resource blocks to the UE 102 within a cell) may be performed at any of the RAN nodes 111 and 112 based on channel quality information fed back from any of the UEs 101 and 102. The downlink resource assignment information may be sent on the PDCCH used for (e.g., assigned to) each of the UEs 101 and 102.

[0026] The PDCCH may use control channel elements (CCEs) to convey the control information. Before being mapped to resource elements, the PDCCH complex-valued symbols may first be organized into quadruplets, which may then be permuted using a sub-block interleaver for rate matching. Each PDCCH may be transmitted using one or more of these CCEs, where each CCE may correspond to nine sets of four physical resource elements known as resource element groups (REGs). Four Quadrature Phase Shift Keying (QPSK) symbols may be mapped to each REG. The PDCCH can be transmitted using one or more CCEs, depending on the size of the downlink control information (DCI) and the channel condition. There can be four or more different PDCCH formats defined in LTE with different numbers of CCEs (e.g., aggregation level, L=l, 2, 4, or 8).

[0027] Some embodiments may use concepts for resource allocation for control channel information that are an extension of the above-described concepts. For example, some embodiments may utilize an enhanced physical downlink control channel (EPDCCH) that uses PDSCH resources for control information transmission. The EPDCCH may be transmitted using one or more enhanced the control channel elements (ECCEs). Similar to above, each ECCE may correspond to nine sets of four physical resource elements known as an enhanced resource element groups (EREGs). An ECCE may have other numbers of EREGs in some situations.

[0028] The RAN 110 is shown to be communicatively coupled to a core network (CN) 120— via an S I interface 113. In embodiments, the CN 120 may be an evolved packet core (EPC) network, a NextGen Packet Core (NPC) network, or some other type of CN. In this embodiment, the S 1 interface 113 is split into two parts: the Sl-U interface 114, which carries traffic data between the RAN nodes 111 and 112 and the serving gateway (S-GW) 122, and the Sl- mobility management entity (MME) interface 115, which is a signaling interface between the RAN nodes 111 and 112 and MMEs 121.

[0029] In this embodiment, the CN 120 comprises the MMEs 121, the S-

GW 122, the Packet Data Network (PDN) Gateway (P-GW) 123, and a home subscriber server (HSS) 124. The MMEs 121 may be similar in function to the control plane of legacy Serving General Packet Radio Service (GPRS) Support Nodes (SGSN). The MMEs 121 may manage mobility aspects in access such as gateway selection and tracking area list management. The HSS 124 may comprise a database for network users, including subscription-related information to support the network entities' handling of communication sessions. The CN 120 may comprise one or several HSSs 124, depending on the number of mobile subscribers, on the capacity of the equipment, on the organization of the network, etc. For example, the HSS 124 can provide support for routing/roaming, authentication, authorization, naming/addressing resolution, location dependencies, etc.

[0030] The S-GW 122 may terminate the S I interface 113 towards the RAN 110, and routes data packets between the RAN 110 and the CN 120. In addition, the S-GW 122 may be a local mobility anchor point for inter-RAN node handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement.

[0031] The P-GW 123 may terminate an SGi interface toward a PDN.

The P-GW 123 may route data packets between the EPC network 123 and external networks such as a network including the application server 130 (alternatively referred to as application function (AF)) via an Internet Protocol (IP) interface 125. Generally, the application server 130 may be an element offering applications that use IP bearer resources with the core network (e.g., UMTS Packet Services (PS) domain, LTE PS data services, etc.). In this embodiment, the P-GW 123 is shown to be communicatively coupled to an application server 130 via an IP communications interface 125. The application server 130 can also be configured to support one or more communication services (e.g., Voice-over-Internet Protocol (VoIP) sessions, PTT sessions, group communication sessions, social networking services, etc.) for the UEs 101 and 102 via the CN 120.

[0032] The P-GW 123 may further be a node for policy enforcement and charging data collection. Policy and Charging Rules Function (PCRF) 126 is the policy and charging control element of the CN 120. In a non-roaming scenario, there may be a single PCRF in the Home Public Land Mobile Network

(HPLMN) associated with a UE's Internet Protocol Connectivity Access

Network (IP-CAN) session. In a roaming scenario with local breakout of traffic, there may be two PCRFs associated with a UE's IP-CAN session: a Home PCRF (H-PCRF) within a HPLMN and a Visited PCRF (V-PCRF) within a Visited Public Land Mobile Network (VPLMN). The PCRF 126 may be

communicatively coupled to the application server 130 via the P-GW 123. The application server 130 may signal the PCRF 126 to indicate a new service flow and select the appropriate Quality of Service (QoS) and charging parameters. The PCRF 126 may provision this rule into a Policy and Charging Enforcement Function (PCEF) (which is in the P-GW 123) with the appropriate traffic flow template (TFT) and QoS class of identifier (QCI), which commences the QoS and charging as specified by the application server 130 via a Gx interface.

[0033] FIG. 2 illustrates example components of a device 200 in accordance with some embodiments. In some embodiments, the device 200 may include application circuitry 202, baseband circuitry 204, Radio Frequency (RF) circuitry 206, front-end module (FEM) circuitry 208, one or more antennas 210, and power management circuitry (PMC) 212 coupled together at least as shown. The components of the illustrated device 200 may be included in a UE or a RAN node. In some embodiments, the device 200 may include less elements (e.g., a RAN node may not utilize application circuitry 202, and instead include a processor/controller to process IP data received from an EPC). In some embodiments, the device 200 may include additional elements such as, for example, memory/storage, display, camera, sensor, or input/output (I/O) interface. In other embodiments, the components described below may be included in more than one device (e.g., said circuitries may be separately included in more than one device for Cloud-RAN (C-RAN) implementations).

[0034] The application circuitry 202 may include one or more application processors. For example, the application circuitry 202 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors,

application processors, etc.). The processors may be coupled with or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications or operating systems to run on the device 200. In some embodiments, processors of application circuitry 202 may process IP data packets received from an EPC.

[0035] The baseband circuitry 204 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 204 may include one or more baseband processors or control logic to process baseband signals received from a receive signal path of the RF circuitry 206 and to generate baseband signals for a transmit signal path of the RF circuitry 206. Baseband processing circuity 204 may interface with the application circuitry 202 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 206. For example, in some embodiments, the baseband circuitry 204 may include a third generation (3G) baseband processor 204A, a fourth generation (4G) baseband processor 204B, a 5G baseband processor 204C, or other baseband processor(s) 204D for other existing generations, generations in development or to be developed in the future (e.g., second generation (2G), sixth generation (6G), etc.). The baseband circuitry 204 (e.g., one or more of baseband processors 204A-D) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 206. In other embodiments, some or all of the functionality of baseband processors 204A-D may be included in modules stored in the memory 204G and executed via a Central Processing Unit (CPU) 204E. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 204 may include Fast-Fourier Transform (FFT), precoding, or constellation mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 204 may include convolution, tail-biting convolution, turbo, Viterbi, or Low Density Parity Check (LDPC)

encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0036] In some embodiments, the baseband circuitry 204 may include one or more audio digital signal processor(s) (DSP) 204F. The audio DSP(s) 204F may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 204 and the application circuitry 202 may be implemented together such as, for example, on a system on a chip (SOC).

[0037] In some embodiments, the baseband circuitry 204 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 204 may support communication with an evolved universal terrestrial radio access network

(EUTPvAN) or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN).

Embodiments in which the baseband circuitry 204 is configured to support radio communications of more than one wireless protocol may be referred to as multi- mode baseband circuitry. [0038] RF circuitry 206 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 206 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 206 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 208 and provide baseband signals to the baseband circuitry 204. RF circuitry 206 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 204 and provide RF output signals to the FEM circuitry 208 for transmission.

[0039] In some embodiments, the receive signal path of the RF circuitry

206 may include mixer circuitry 206A, amplifier circuitry 206B and filter circuitry 206C. In some embodiments, the transmit signal path of the RF circuitry 206 may include filter circuitry 206C and mixer circuitry 206A. RF circuitry 206 may also include synthesizer circuitry 206D for synthesizing a frequency for use by the mixer circuitry 206A of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 206A of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 208 based on the synthesized frequency provided by synthesizer circuitry 206D. The amplifier circuitry 206B may be configured to amplify the down-converted signals and the filter circuitry 206C may be a low- pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 204 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 206A of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0040] In some embodiments, the mixer circuitry 206A of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 206D to generate RF output signals for the FEM circuitry 208. The baseband signals may be provided by the baseband circuitry 204 and may be filtered by filter circuitry 206C.

[0041] In some embodiments, the mixer circuitry 206A of the receive signal path and the mixer circuitry 206A of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and upconversion, respectively. In some embodiments, the mixer circuitry 206A of the receive signal path and the mixer circuitry 206A of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 206A of the receive signal path and the mixer circuitry 206A may be arranged for direct downconversion and direct upconversion, respectively. In some embodiments, the mixer circuitry 206A of the receive signal path and the mixer circuitry 206A of the transmit signal path may be configured for super-heterodyne operation.

[0042] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 206 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 204 may include a digital baseband interface to communicate with the RF circuitry 206.

[0043] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0044] In some embodiments, the synthesizer circuitry 206D may be a fractional -N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 206D may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[0045] The synthesizer circuitry 206D may be configured to synthesize an output frequency for use by the mixer circuitry 206A of the RF circuitry 206 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 206D may be a fractional N/N+l synthesizer.

[0046] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 204 or the applications processor 202 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a lookup table based on a channel indicated by the applications processor 202.

[0047] Synthesizer circuitry 206D of the RF circuitry 206 may include a divider, a delay -locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0048] In some embodiments, synthesizer circuitry 206D may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 206 may include an IQ/polar converter.

[0049] FEM circuitry 208 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 210, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 206 for further processing. FEM circuitry 208 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 206 for transmission by one or more of the one or more antennas 210. In various embodiments, the amplification through the transmit or receive signal paths may be done solely in the RF circuitry 206, solely in the FEM 208, or in both the RF circuitry 206 and the FEM 208.

[0050] In some embodiments, the FEM circuitry 208 may include a

TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include an LNA to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 206). The transmit signal path of the FEM circuitry 208 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 206), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 210).

[0051] In some embodiments, the PMC 212 may manage power provided to the baseband circuitry 204. In particular, the PMC 212 may control power-source selection, voltage scaling, battery charging, or DC-to-DC conversion. The PMC 212 may often be included when the device 200 is capable of being powered by a battery, for example, when the device is included in a UE. The PMC 212 may increase the power conversion efficiency while providing desirable implementation size and heat dissipation characteristics.

[0052] While FIG. 2 shows the PMC 212 coupled only with the baseband circuitry 204. However, in other embodiments, the PMC 2 12 may be additionally or alternatively coupled with, and perform similar power management operations for, other components such as, but not limited to, application circuitry 202, RF circuitry 206, or FEM 208.

[0053] In some embodiments, the PMC 212 may control, or otherwise be part of, various power saving mechanisms of the device 200. For example, if the device 200 is in an RRC_Connected state, where it is still connected to the RAN node as it expects to receive traffic shortly, then it may enter a state known as Discontinuous Reception Mode (DRX) after a period of inactivity. During this state, the device 200 may power down for brief intervals of time and thus save power.

[0054] If there is no data traffic activity for an extended period of time, then the device 200 may transition to an RRC Idle state. In the RRC Idle state, the device 200 may disconnect from the network and avoid performing operations such as channel quality feedback, handover, etc. The device 200 may enter a very low power state and perform paging in which the device 200 may periodically wake up to listen to the network and then power down again. To receive data, the device 200 may transition back to the RRC_Connected state.

[0055] An additional power saving mode may allow a device to be unavailable to the network for periods longer than a paging interval (ranging from seconds to a few hours). During this time, the device is totally unreachable to the network and may power down completely. Any data sent during this time incurs a large delay and it is assumed the delay is acceptable.

[0056] Processors of the application circuitry 202 and processors of the baseband circuitry 204 may be used to execute elements of one or more instances of a protocol stack. For example, processors of the baseband circuitry 204, alone or in combination, may be used execute Layer 3, Layer 2, or Layer 1 functionality, while processors of the application circuitry 204 may utilize data (e.g., packet data) received from these layers and further execute Layer 4 functionality (e.g., transmission communication protocol (TCP) and user datagram protocol (UDP) layers). As referred to herein, Layer 3 may comprise a radio resource control (RRC) layer, described in further detail below. As referred to herein, Layer 2 may comprise a medium access control (MAC) layer, a radio link control (RLC) layer, and a packet data convergence protocol (PDCP) layer, described in further detail below. As referred to herein, Layer 1 may comprise a physical (PHY) layer of a UE/RAN node, described in further detail below.

[0057] FIG. 3 illustrates example interfaces of baseband circuitry in accordance with some embodiments. As discussed above, the baseband circuitry 204 of FIG. 2 may comprise processors 204A-XT04E and a memory 204G utilized by said processors. Each of the processors 204A-XT04E may include a memory interface, 304A-XU04E, respectively, to send/receive data to/from the memory 204G.

[0058] The baseband circuitry 204 may further include one or more interfaces to communicatively couple to other circuitries/devices, such as a memory interface 312 (e.g., an interface to send/receive data to/from memory external to the baseband circuitry 204), an application circuitry interface 314 (e.g., an interface to send/receive data to/from the application circuitry 202 of FIG. 2), an RF circuitry interface 316 (e.g., an interface to send/receive data to/from RF circuitry 206 of FIG. 2), a wireless hardware connectivity interface 318 (e.g., an interface to send/receive data to/from Near Field Communication (NFC) components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components), and a power management interface 320 (e.g., an interface to send/receive power or control signals to/from the PMC 212).

[0059] FIG. 4 is an illustration of a control plane protocol stack in accordance with some embodiments. In this embodiment, a control plane 400 is shown as a communications protocol stack between the UE 101 (or alternatively, the UE 102), the RAN node 111 (or alternatively, the RAN node 112), and the MME 121.

[0060] The PHY layer 401 may transmit or receive information used by the MAC layer 402 over one or more air interfaces. The PHY layer 401 may further perform link adaptation or adaptive modulation and coding (AMC), power control, cell search (e.g., for initial synchronization and handover purposes), and other measurements used by higher layers, such as the RRC layer 405. The PHY layer 401 may still further perform error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, modulation/demodulation of physical channels, interleaving, rate matching, mapping onto physical channels, and Multiple Input Multiple Output (MIMO) antenna processing.

[0061] The MAC layer 402 may perform mapping between logical channels and transport channels, multiplexing of MAC service data units (SDUs) from one or more logical channels onto transport blocks (TB) to be delivered to PHY via transport channels, de-multiplexing MAC SDUs to one or more logical channels from transport blocks (TB) delivered from the PHY via transport channels, multiplexing MAC SDUs onto TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), and logical channel prioritization.

[0062] The RLC layer 403 may operate in a plurality of modes of operation, including: Transparent Mode (TM), Unacknowledged Mode (UM), and Acknowledged Mode (AM). The RLC layer 403 may execute transfer of upper layer protocol data units (PDUs), error correction through automatic repeat request (ARQ) for AM data transfers, and concatenation, segmentation and reassembly of RLC SDUs for UM and AM data transfers. The RLC layer 403 may also execute re-segmentation of RLC data PDUs for AM data transfers, reorder RLC data PDUs for UM and AM data transfers, detect duplicate data for UM and AM data transfers, discard RLC SDUs for UM and AM data transfers, detect protocol errors for AM data transfers, and perform RLC re-establishment.

[0063] The PDCP layer 404 may execute header compression and decompression of IP data, maintain PDCP Sequence Numbers (SNs), perform in-sequence delivery of upper layer PDUs at re-establishment of lower layers, eliminate duplicates of lower layer SDUs at re-establishment of lower layers for radio bearers mapped on RLC AM, cipher and decipher control plane data, perform integrity protection and integrity verification of control plane data, control timer-based discard of data, and perform security operations (e.g., ciphering, deciphering, integrity protection, integrity verification, etc.).

[0064] The main services and functions of the RRC layer 405 may include broadcast of system information (e.g., included in Master Information Blocks (MIBs) or System Information Blocks (SIBs) related to the non-access stratum (NAS)), broadcast of system information related to the access stratum (AS), paging, establishment, maintenance and release of an RRC connection between the UE and E-UTRAN (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), establishment, configuration, maintenance and release of point to point Radio Bearers, security functions including key management, inter radio access technology (RAT) mobility, and measurement configuration for UE

measurement reporting. The MIBs and SIBs may comprise one or more information elements (IEs), which may each comprise individual data fields or data structures.

[0065] The UE 101 and the RAN node 111 may utilize a Uu interface

(e.g., an LTE-Uu interface) to exchange control plane data via a protocol stack comprising the PHY layer 401, the MAC layer 402, the RLC layer 403, the PDCP layer 404, and the RRC layer 405.

[0066] The non-access stratum (NAS) protocols 406 form the highest stratum of the control plane between the UE 101 and the MME 121. The NAS protocols 406 support the mobility of the UE 101 and the session management procedures to establish and maintain IP connectivity between the UE 101 and the P-GW 123.

[0067] The S 1 Application Protocol (S 1 -AP) layer 415 may support the functions of the SI interface and comprise Elementary Procedures (EPs). An EP is a unit of interaction between the RAN node 111 and the CN 120. The S 1-AP layer services may comprise two groups: UE-associated services and non UE- associated services. These services perform functions including, but not limited to: E-UTRAN Radio Access Bearer (E-RAB) management, UE capability indication, mobility, NAS signaling transport, RAN Information Management (RIM), and configuration transfer.

[0068] The Stream Control Transmission Protocol (SCTP) layer

(alternatively referred to as the SCTP/IP layer) 414 may ensure reliable delivery of signaling messages between the RAN node 111 and the MME 121 based, in part, on the IP protocol, supported by the IP layer 413. The L2 layer 412 and the LI layer 411 may refer to communication links (e.g., wired or wireless) used by the RAN node and the MME to exchange information.

[0069] The RAN node 111 and the MME 121 may utilize an S 1 -MME interface to exchange control plane data via a protocol stack comprising the LI layer 411, the L2 layer 412, the IP layer 413, the SCTP layer 414, and the Sl-AP layer 415. [0070] FIG. 5 is an illustration of a user plane protocol stack in accordance with some embodiments. In this embodiment, a user plane 500 is shown as a communications protocol stack between the UE 101 (or alternatively, the UE 102), the RAN node 111 (or alternatively, the RAN node 112), the S-GW 122, and the P-GW 123. The user plane 500 may utilize at least some of the same protocol layers as the control plane 400. For example, the UE 101 and the RAN node 111 may utilize a Uu interface (e.g., an LTE-Uu interface) to exchange user plane data via a protocol stack comprising the PHY layer 401, the MAC layer 402, the RLC layer 403, the PDCP layer 404.

[0071] The General Packet Radio Service (GPRS) Tunneling Protocol for the user plane (GTP-U) layer 504 may be used for carrying user data within the GPRS core network and between the radio access network and the core network. The user data transported can be packets in any of IPv4, IPv6, or PPP formats, for example. The UDP and IP security (UDP/IP) layer 503 may provide checksums for data integrity, port numbers for addressing different functions at the source and destination, and encryption and authentication on the selected data flows. The RAN node 111 and the S-GW 122 may utilize an Sl-U interface to exchange user plane data via a protocol stack comprising the L 1 layer 411, the L2 layer 412, the UDP/IP layer 503, and the GTP-U layer 504. The S-GW 122 and the P-GW 123 may utilize an S5/S8a interface to exchange user plane data via a protocol stack comprising the LI layer 411, the L2 layer 412, the UDP/IP layer 503, and the GTP-U layer 504. As discussed above with respect to FIG. 4, NAS protocols support the mobility of the UE 101 and the session management procedures to establish and maintain IP connectivity between the UE 101 and the P-GW 123.

[0072] FIG. 6 is a block diagram illustrating components, according to some example embodiments. The components of FIG. 6 are able to read instructions from a machine-readable or computer-readable medium (e.g., a non- transitory machine-readable storage medium) and perform any one or more of the methodologies discussed herein. Specifically, FIG. 6 shows a diagrammatic representation of hardware resources 600 including one or more processors (or processor cores) 610, one or more memory /storage devices 620, and one or more communication resources 630, each of which may be communicatively coupled via a bus 640. For embodiments where node virtualization (e.g., NFV) is utilized, a hypervisor 602 may be executed to provide an execution environment for one or more network slices/sub-slices to utilize the hardware resources 600.

[0073] The processors 610 (e.g., a central processing unit (CPU), a reduced instruction set computing (RISC) processor, a complex instruction set computing (CISC) processor, a graphics processing unit (GPU), a digital signal processor (DSP) such as a baseband processor, an application specific integrated circuit (ASIC), a radio-frequency integrated circuit (RFIC), another processor, or any suitable combination thereof) may include, for example, a processor 612 and a processor 614.

[0074] The memory/storage devices 620 may include main memory, disk storage, or any suitable combination thereof. The memory/storage devices 620 may include, but are not limited to any type of volatile or non-volatile memory such as dynamic random access memory (DRAM), static random-access memory (SRAM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), Flash memory, solid-state storage, etc.

[0075] The communication resources 630 may include interconnection or network interface components or other suitable devices to communicate with one or more peripheral devices 604 or one or more databases 606 via a network 608. For example, the communication resources 630 may include wired communication components (e.g., for coupling via a Universal Serial Bus (USB)), cellular communication components, NFC components, Bluetooth® components (e.g., Bluetooth® Low Energy), Wi-Fi® components, and other communication components.

[0076] Instructions 650 may comprise software, a program, an application, an applet, an app, or other executable code for causing at least any of the processors 610 to perform any one or more of the methodologies discussed herein. The instructions 650 may reside, completely or partially, within at least one of the processors 610 (e.g., within the processor's cache memory), the memory /storage devices 620, or any suitable combination thereof. In some embodiments, the instructions 650 may reside on a tangible, nonvolatile communication device readable medium, which may include a single medium or multiple media. Furthermore, any portion of the instructions 650 may be transferred to the hardware resources 600 from any combination of the peripheral devices 604 or the databases 606. Accordingly, the memory of processors 610, the memory/storage devices 620, the peripheral devices 604, and the databases 606 are examples of computer-readable and machine-readable media.

[0077] As above, mobility-related issues in LTE communications continue to rise in importance with the increasing penetration of UEs into everyday life. Even though advanced networks such as LTE and 4G networks continue to grow in coverage, there are a number of areas within the United States and around the world in which lower-speed legacy networks have not yet been replaced. When a UE enters such an area from an area of VoLTE coverage, Single Radio Voice Call Continuity (SRVCC) handover may occur from LTE to a legacy circuit switched voice system, such as GSM, UMTS or CDMA lx (WCDMA) to enable packet domain calls to continue in a seamless manner. SRVCC enables Inter Radio Access Technology (RAT) handover as well as a handover from packet data to circuit switched (CS) data voice calls. SRVCC may include both RAT transfer (e.g., from a 3G network to a 2G network) as well as session transfer that transfers access control and voice media anchoring from the Evolved Packet Core (EPC) of the packet-switched LTE network to the legacy circuit-switched network. During the handover process, the Call Session Control Function (CSCF) within the IP Multimedia System (IMS) architecture may maintain the control of the whole operation. This may permit existing quality of service (QoS) of the VoLTE call to be maintained. SRVCC handover may enable QoS continuity (existing QoS).

[0078] In particular, the SRVCC handover process may be initiated by a request for session transfer from the IMS CSCF. The IMS CSCF may respond a command to both the LTE and legacy network. The LTE network may receive a RAN handover command through the MME and LTE RAN. The handover command may instruct the UE to prepare to move to a circuit-switched network for the voice call. The legacy circuit-switched network may receive a session transfer response preparing the legacy circuit-switched network to accept the call from the LTE network. After the commands have been executed and acknowledged, the call may be switched to the legacy network. After the call transfer, the IMS CSCF may still retain control of the call.

[0079] However, the interruption time when handing over from an LTE

RAN to a legacy RAN may severely impact the user experience. Thus, it may be desirable to avoid or at least minimize the possibility of SRVCC handover to maintain the VoLTE service in the Evolved Packet Service (EPS) without damaging the user experience. This may be accomplished, in some

embodiments, through the use by the UE of a codec with a lower QoS than for typical LTE communications. As is known, a codec (also referred to as a coder- decoder) may be implemented by the processing circuitry or may be a separate device. The codec may encode data to be transmitted and decode received data, which may or may not be encrypted. Codecs may also compress data to be transmitted and decompress received data. The codec used may be lossy (which may increase compression) or lossless (which may preserve quality better than lossy codecs). Audio and video data encoded with a codec may be placed into an Audio Video Interleave (AVI) container.

[0080] In some embodiments, codec information may be provided in a

Codec-Data Attribute-Value Pair (AVP) of the Diameter protocol. Diameter AVPs in a Diameter message may carry Authentication, Security, and

Application Data, among others. The Codec-Data AVP may have an AVP code 524 and be of type OctetString. The Diameter message may, in general, contain a Diameter header and a variable number of AVPs that encapsulate information relevant to the Diameter message.

[0081] In particular, the container may in some embodiments include a

Media-Component-Description AVP in which the Codec-Data AVP is provided. The Media-Component-Description AVP may have an AVP code 517 and be of type Grouped. The Media-Component-Description AVP may contain service information for a single media component within an Application Function (AF) session or AF signalling information. The service information may be based on Session Description Information exchanged between the AF and an AF session client in the UE. The information may be used by the PCRF to determine authorized QoS and IP flow classifiers for bearer authorization and Policy Control and Charging rule selection. If a conflict exist in the Codec-Data AVP information contained in other AVPs, either within the Media-Component- Description AVP or within a corresponding Media-Component-Description AVP in a previous message, the information in the current the Media- Component-Description AVP may take precedence over other codec information.

[0082] In some embodiments, the EPS bearer may support an Adaptive

Multi-Rate Wideband (AMR-WB) codec by default for voice service. The AMR-WB codec may have higher QoS requirements and lower robustness than an Enhanced Voice Service (EVS) codec. This may permit a potential SRVCC handover to be avoided - if the codec for the ongoing voice service can be adjusted to the EVS codec from the AMR-WB codec, and the eNB is able determine that such change has occurred.

[0083] In some embodiments, the eNB may determine that the LTE radio coverage of the UE does not meet a predetermined level. The eNB may in consequence inform the CN element (e.g., MME), the IMS network element or the UE of the coverage problem. The IMS client, IMS network element and CN element may subsequently negotiate a codec change during the voice session. This is to say that once the codec is changed, the IMS network element may initiate an IP Connectivity Access Network (IP-CAN) Session modification to create or modify an EPS bearer to use a lower QoS requirement in the EPS. Alternatively, the UE may detect a radio coverage issue. In this case, the UE may inform the IMS client of the problem. The IMS client may then negotiate the codec change with the IMS network element. The IMS network element may subsequently initiate the IP-CAN Session modification that uses the lower QoS requirement in the EPS.

[0084] To effect this, in some embodiments, the eNB can be pre- configured with multiple thresholds (e.g., TH1 and TH2, where TH2 is higher than TH1) for one or more physical layer parameters. The parameters may include Sidelink Reference Signal Received Power (S-RSRP), Sidelink

Discovery Reference Signal Received Power (SD-RSRP), PSSCH reference signal received power (PSSCH-RSRP), Sidelink reference signal strength indicator (S-RSSI) or other signal parameters used by the UE to measure coverage. The UE may encode and report the measurement(s) in a measurement report based on predetermined conditions indicated in RRC signaling during connection or reconnection between the UE and eNB. The eNB may decode the measurement report and determine, for example, whether or not the UE is to be handed over to a different type of service or to a different eNB (or AP when, for example, LTE-WLAN Aggregation (LWA) is used). As discussed, the threshold used by the eNB to determine handover may be dependent on the type of codec being used by the UE. In some embodiments, the reporting threshold provided by the eNB and used by the UE may be independent of the codec type; in other embodiments, the reporting thresholds may be dependent on the codec type.

[0085] In particular, during initial setup of the VoIP voice session for a

UE, the PCRF in the CN may be notified and/or may store which codec is being used by the UE. The IMS network may provide the notification of the codec in IMS service information from the P-CSCF to the PCRF. The information may be encoded at the P-CSCF and decoded at the PCRF. The notification may indicate, for example the type of codec - whether the UE is using a high robustness codec (e.g. the EVS codec) or a low robustness codec (e.g. the AMR- WB codec), or the particular codec used. The Maximum Packet Loss Rate (UL, DL) may be negotiated for each direction (UL, DL). The Maximum Packet Loss Rate (UL, DL) may be based on the local configuration. The PCRF may thus set the Maximum Packet Loss Rate (UL, DL) corresponding to either the most robust codec mode or the least robust codec mode of the negotiated set in each direction, based on the local configuration. The PCRF may then provide a container to the eNB. The container may include an indication of the type of codec being used or specific codec information. In the former case, a single bit may be used to indicate either high or low robustness codec use.

[0086] The eNB may employ the information in the container to determine whether SRVCC handover is appropriate. For example, when the UE voice service is using a high robustness codec, the eNB may only execute a SRVCC handover when the radio coverage is below TH1; otherwise, the eNB may execute a SRVCC handover when the radio coverage is below TH2. This may reduce the SRVCC handover in cases in which the high robustness codec is used by the UE compared with when a low robustness codec is used by the UE.

[0087] FIG. 7 illustrates a handover process in which a container is provisioned to the eNB in accordance with some embodiments. The various components shown in FIG. 7 may be described in relation to FIGS. 1-6. Some of the processes that occur during handover may not be shown for convenience.

[0088] At operation 1, during the IMS based voice session setup or modification procedure, the IMS network element 714 may send the codec information to the CN in an Authorize-Authenticate (AA)-Request message as defined in 3GPP TS 29.214. The IMS network element 714 may have a Transport, Session and Control Layer, and Applications and Services layer. The Session and Control Layer may include Session Initiation Protocol (SIP) servers that implement the CSCF. The CSCF may include a Proxy CSCF (P-CSCF), an Interrogating CSCF (I-CSCF), and a Serving CSCF (S-CSCF, which use the SIP protocol to communicate with each other and Application Servers and use the Diameter protocol to communicate with the HSS and/or the PCRF. In some embodiments, the IMS network element 714 may be the P-CSCF. The P-CSCF 714 may be the first IMS network element encountered when the UE is trying to establish a VoLTE call and may be in a home or visited network. The P-CSCF 714 may locate an I-CSCF for the user and the I-CSCF locate an S-CSCF for the user and may otherwise interact with the PCRF for billing and policy rules purposes, maintain a security association with the UE and compress/decompress SIP messages. As described herein, the PCRF 712 in the CN may in particular receive the codec information in IMS service information.

[0089] A default bearer for the UE may be used to set up a VoLTE call.

To set up the default bearer, the UE may send an ATTACH REQUEST to the MME. The MME may query the HSS to retrieve the subscriber's profile. The profile may contain a default Access Point Name (APN) for the UE, which for VoLTE calls may be IMS. The MME may then determine a SGW and Packet Data Network Gateway (PGW) for the call. The eNB, S-GW and PGW may establish a default bearer and the PGW may supply the UE with an IP address and the P-CSCF IP address. When the default bearer is established, the UE may store the UE and P-CSCF IP address.

[0090] Once attached to the LTE network, the UE may initiate the

VoLTE call by requesting SIP registration. The UE may forward the SIP Registration message to the P-CSCF. The message may contain the home domain of the UE. The P-CSCF may use this information to identify an I-CSCF in the home network of the UE using a DNS server. The P-CSCF may forward the Registration request to the I-CSCF, which may be sent to the S-CSCF.

[0091] At reception of the IMS service information from the P-CSCF, the PCRF may determine the Maximum Packet Loss Rate for UL and DL communications based on the IMS service information. The IMS service information may include the codec information (e.g. type). The P-CSCF may send the IMS service information to the PCEF along with the Policy and

Charging Control (PCC) (QoS policy message) rule for the voice media. Based on the codec information, at operation 2, the PCRF 712 may set the Maximum Packet Loss Rate (UL, DL) corresponding to either the most robust codec mode or the least robust codec mode in each direction and may send a container to the PGW and/or PCEF 710 in an IP-CAN Session Modification message. The container may provide indication of use of a high or low robustness codec or other codec information, such as the specific codec being used.

[0092] The PGW/PCEF 710 may then send a Create Bearer Request message to the SGW 708 at operation 3. The Create Bearer Request message may include the container with the codec information and/or may indicate the Maximum Packet Loss Rate for UL and DL communications, which may be based on the codec used. In some embodiments, the PCC rule received from the PCRF 714 may be bound to a QoS Class Identifier (QCI)=1 bearer. The support for SRVCC may use a QCI=1 bearer only for IMS speech sessions. A QCI=1 bearer may be associated with voice services (voice media), provide a guaranteed bit rate (dedicated bearer), have a priority of 2, packet delay budget of 100ms, packet error loss rate of 10^"2. [0093] The SGW 708 may at operation 4 send a Create Bearer Request message to the MME 706. The Create Bearer Request message may include the container.

[0094] After receiving the Create Bearer Request message, the MME 706 may transmit the container to the eNB 704 at operation 5. The container may be provided in a Bearer Setup Request/Session Management Request message. If the UE 702 is in the ECM-IDLE state the MME 706 may trigger a Network Triggered Service Request. The MME 706 may check if the UE 702 can support the establishment of an additional user plane radio bearer based on the maximum number of user plane radio bearers indicated by the UE 702 in the UE Network Capability IE. The MME 706 may have received the UE capabilities during initial attach. During a Tracking Area Update (TAU) procedure, if the MME supports SRVCC and if the UE SRVCC capability has changed, the MME may inform the HSS with the UE SRVCC capability e.g. for further IMS registration. The SRVCC CS to PS handover event trigger may trigger a PCEF interaction with the PCRF to inform that a CS to PS handover procedure has been detected. The PCRF may ensure voice media over the default bearer during the course of the CS to PS SRVCC procedure. In support for SRVCC, only QCI=1 may be used for IMS speech sessions.

[0095] Specifically, the MME 706 may select an EPS Bearer Identity that has not yet been assigned to the UE 702. The MME 706 may then build a Session Management Request for the UE 702. The MME 706 may use the EPS bearer QoS parameters to derive corresponding PDP context parameters QoS Negotiated, Radio Priority, Packet Flow Id and TI Session and include these in the Management Request. The MME 706 may signal the Bearer Setup Request (EPS Bearer Identity, EPS Bearer QoS, Maximum Packet Loss Rate (UL, DL), Session Management Request, Sl-TEID) message to the eNB 704 at operation 5.

[0096] The eNB 704 may store the container for the UE voice session in memory and map the EPS Bearer QoS to a Radio Bearer QoS. Based on the UE configuration and the received indication from the Policy Control Function, the eNB may decide when to initiate a SRVCC handover. When the SRVCC handover is to occur, the eNB 704 may at operation 6 send a RRC Connection Reconfiguration message to UE 702.

[0097] The UE 702 may prepare for the handover, storing the QoS

Negotiated, Radio Priority, Packet Flow Id and TI, received in the Session Management Request, for use when accessing the network via GERAN or

UTRAN. The UE 702 may store the EPS Bearer Identity and link the dedicated bearer to the default bearer indicated by the Linked EPS Bearer Identity (LBI). The UE 702 may provide the EPS Bearer QoS parameters to the application handling the traffic flow. The UE 702 may then acknowledge the radio bearer activation by responding at operation 7 with a RRC Connection Reconfiguration Complete message to eNB 704.

[0098] The eNB 704 may at operation 8 respond to the Bearer Setup

Request/Session Management Request message with a Bearer Setup Response to the MME 706.

[0099] The UE NAS layer may build a Session Management Response.

The Session Management Response may include the EPS Bearer Identity. The UE 702 may then at operation 9 send a Direct Transfer (Session Management Response) message to the eNB 704.

[00100] The eNB 704 may, in response to reception of the Direct Transfer message, send an Uplink NAS Transport (Session Management Response) message to the MME 706 at operation 10.

[00101] The MME 706 may at operation 11 respond with a Create Bearer Response message to the SGW 708. The MME 706 may maintain the Mobility Management context and EPS bearer context information for the UE when the UE in the ECM-IDLE, ECM-CONNECTED and EMM-DEREGI STERED states. The context fields in the context may include a list of codecs supported in the CS domain.

[00102] The SGW 708 may at operation 12 respond with a Create Bearer Response message to the PGW/PCEF 710.

[00103] The PGW/PCEF 710 may at operation 13 respond with a IP-CAN

Session Modification Response message to the PCRF 712. [00104] The PCRF 712 may at operation 14 respond with a AA-Answer message to the IMS network element 714.

[00105] In another embodiment, the eNB may trigger session

modification. Similar to the embodiment of FIG. 7, the eNB can be pre- configured with multiple thresholds, e.g., TH1 and TH2, where TH2 is higher than TH1. The thresholds may be for one or more of the physical layer parameters such as S-RSRP, SD-RSRP, PSSCH-RSRP, and/or S-RSSI.

[00106] Unlike the embodiment of FIG. 7, one of the CN elements may provide to the eNB a notification event trigger for bad radio coverage of the UE. In some embodiments, the PCRF may provide the trigger to the eNB. The IMS network may indicate to the Policy Control Function during voice session establishment whether a codec change under bad radio coverage is supported by the UE. The notification event trigger may be part of a QoS rule for the voice service.

[00107] When a UE has ongoing voice service using a codec with high

QoS and low robustness (e.g. the AMR-WB codec) and the notification event trigger for bad radio coverage is enabled for the UE, the eNB may apply a set of rules to use the thresholds. These rules may include a first rule that when the radio coverage is above TH2, the eNB will not notify the bad radio coverage to the CN. A second rule applied by the eNB may be that when the radio coverage is lower than TH2 but above TH1, the eNB will trigger a bad radio coverage notification to the PCRF. The PCRF may then be responsible for the decision of changing voice codec to a codec with lower QoS requirements and higher robustness (e.g. the EVS codec). A third rule applied by the eNB may be that when the radio coverage is lower than THl, a SRVCC handover will be triggered.

[00108] In this embodiment, the session modification procedure may be triggered by eNB and proceed under the control of the PCRF with IMS involvement. This is shown in more detail in FIG. 8, which illustrates an eNB- triggered session modification procedure in accordance with some embodiments. The various components shown in FIG. 8 may be described in relation to FIGS. 1-6. Some of the processes that occur during handover may not be shown for convenience.

[00109] During the IMS based voice session setup procedure, the IMS network element may at operation 1 send codec information to the CN in AA- Req message as defined in 3GPP TS 29.214. The IMS network element may be the P-CSCF 814, while the CN element may be the PCRF 812, for example.

[00110] The PCRF 812 may at operation 2 provision an event trigger for bad radio coverage notification to the PCEF 810. The event trigger may be provisioned in an IP-CAN Session Modification message.

[00111] In response to receiving the IP-CAN Session Modification message, at operation 3 the PCEF 810 may send the event trigger to the SGW 808.

[00112] At operation 4, the SGW 808 may then send the event trigger to the MME 806.

[00113] At operation 5, the MME 806 may subsequently send the event trigger to the eNB 804, which may enforce the event trigger.

[00114] More specifically, the eNB 804 may detect the bad radio coverage condition at operation 6. The event trigger for notification may thus be triggered for the UE 802.

[00115] The eNB 804 may notify the MME 806 about the bad radio coverage condition at operation 7.

[00116] The MME 806, having received the message from the MME 806, may further send the bad radio coverage condition notification to the SGW 808 at operation 8.

[00117] The SGW 808 may further send the bad radio coverage condition to the PGW/PCEF 810 at operation 9.

[00118] The PGW/PCEF 810 may then notify the PCRF 812 about the bad radio coverage condition at operation 10.

[00119] The PCRF 812 may further notify the IMS network element 814 about the bad radio coverage condition at operation 11.

[00120] The IMS network element 814 may decide to change the codec information for the UE's ongoing voice service. In this case, the IMS network element 814 may send an AA-Req message as defined in 3GPP TS 29.214 to the PCRF 812. The IP-CAN Session Modification procedure as defined in clause 8.4.2 of 3GPP TS 23.203 may thus be triggered.

[00121] If the requested QoS handling is successful, the corresponding IMS network element 814 may send a SIP request message to IMS Client with the new codec information. The SIP request message may be a SIP relNVITE or SIP UPDATE, for example.

[00122] If IMS Client supports the new codec, the IMS Client may accept use of the new codec for the ongoing voice session. In this case, the IMS client may reply with a SIP 200 (OK) .

[00123] FIG. 9 illustrates a UE-triggered session modification procedure in accordance with some embodiments. The various components shown in FIG. 9 may be described in relation to FIGS. 1-6. Some of the processes that occur during handover may not be shown for convenience.

[00124] The UE, similar to the eNB in the embodiments shown in FIGS. 7 and 8, can be pre-configured with multiple thresholds, e.g., THl and TH2, where TH2 is higher than THl . The thresholds may be for one or more of the physical layer parameters such as S-RSRP, SD-RSRP, PSSCH-RSRP, and/or S-RSSI.

[00125] When the UE has an ongoing voice service using a high QoS and low robustness codec (e.g. AMR-WB codec), use of the thresholds may be similar to the above embodiments. In particular, when the radio coverage is above TH2, the UE may do nothing. When the radio coverage is lower than TH2 but above THl, the UE may notify IMS Client to renegotiate the codec to a codec with lower QoS requirements and higher robustness (e.g. a EVS codec) with IMS network. When the radio coverage is lower than THl, the UE may do nothing, and may merely wait for the RAN node to initiate a SRVCC handover.

[00126] The session modification procedure may then proceed under the control of the PCF with IMS involvement.

[00127] Specifically, as shown in FIG. 9, the UE 902 may detect the bad radio coverage condition at operation 1. The UE 902 may in response notify the IMS network element 914. [00128] The IMS Client may decide to renegotiate the voice service codec with the IMS network element 914 at operation 2. The IMS Client may use a SIP Request. The EVS codec may be used for the target of the renegotiation. The SIP Request may be a SIP re INVITE or UPDATE.

[00129] The IMS network element 914 may decide to change the codec information for the UE's ongoing voice service. The IMS network element 914 may send a Session modification request message to the PCRF 912 at operation 3. The Session modification request message may be Modification of Service Information defined in 3 GPP TS 29.214.

[00130] The PCRF 912 may decide the QoS and charging rules for the voice service with the new codec. At operation 4, the PCRF 912 may send the Session Modification Request message to the PGW/PCEF 910.

[00131] The PGW/PCEF 910 may at operation 5 send the Session Modification Request message to the SGW 908 with the modified QoS rules.

[00132] The SGW 908 may then at operation 6 send the Session

Modification Request message to the MME 906 with the modified QoS rules.

[00133] The MME 906 may respond at operation 7 and may send the

Session Modification Request message to the eNB 904 with the modified QoS rules. The Session Modification Request message may be a S l-AP modification message.

[00134] The eNB 904 may reconfigure the RRC resource with the UE 902 at operation 8.

[00135] The eNB 904 may at operation 9 respond with the Session Modification Response message to the MME 906 with proper result of QoS change handling.

[00136] The MME 906 may respond at operation 10 with the Session

Modification Response message to the SGW 908 with proper result of QoS change handling.

[00137] The SGW 908 may respond at operation 11 with the Session Modification Response message to the PGW/PCEF 910 with proper result of QoS change handling. [00138] The PGW/PCEF 910 may respond at operation 12 with the

Session Modification Response message to the PCRF 912 with proper result of QoS change handling.

[00139] The PCRF 912 may respond at operation 13 with the Session Modification Response message to the IMS network element 914 with proper result of QoS change handling.

[00140] The IMS network element 914 may recognize the QoS and Charging rule change has been accepted by the UE 902, RAN and Core Network. The IMS network element 914 may at operation 14 respond to the IMS Client at the UE 902 with a SIP 200 (OK) .

[00141] In some of the embodiments shown in FIGS. 7-9, during a voice session setup, the PCRF may be notified from the IMS network whether the UE is using a high robustness codec (e.g. EVS) or low robustness codec (e.g. AMR- WB). The PCRF may then provide a container to the eNB. The container may provide an indication of high or low robustness of the codec, or may provide codec information. The eNB may be provisioned with an event trigger for notification of bad radio coverage for the UE by the PCRF. The IMS network can tell the PCRF about the codec information for the voice session during the voice session establishment. The notification event trigger can be part of a QoS rule for voice service. When the eNB detects the bad radio coverage condition, the eNB may notify the PCRF about the bad radio coverage via control plane messaging (RRC). The PCRF may notify the IMS network about the bad radio coverage. The IMS network may subsequently initiate the IP-CAN Session Modification procedure towards the UE via the CN, RAN node on the control plane. In some embodiments, the UE may detect the bad radio coverage condition, and subsequently notify the IMS Client. The IMS Client may renegotiate the voice service codec change with the IMS network. The IMS network may in response initiate the IP-CAN Session Modification procedure with the PCRF, PGW/PCEF, SGW, MME, RAN node and UE.

[00142] The eNB may thus have a memory and processing circuitry. The processing circuitry may, in some embodiments, be arranged to decode a measurement report from a UE. The measurement report may comprise a measurement of at least one parameter. The processing circuitry may further be arranged to determine, based on the at least one parameter, whether to execute SRVCC handover of the UE. The determination of whether to execute the SRVCC handover may be dependent on a SRVCC threshold. The processing circuitry may further be arranged to initiate SRVCC handover in response to the determination to execute the SRVCC handover. The codec type may comprise one of a high robustness codec or a low robustness codec. The high robustness codec may be an EVS codec, the low robustness codec may be an AMR-WB codec and/or the AMR-WB may be a default codec for voice service. The processing circuitry may further be arranged to, prior to reception of the measurement report from the UE, decode a container from a MME, the container comprising an indication of the codec type. The container may be received in a Bearer Setup Request/Session Management Request message from the MME. The processing circuitry may further be arranged to encode, for transmission to the MME in response to the Bearer Setup Request/Session Management Request message, a Bearer Setup Response message. The processing circuitry may further be arranged to encode, for transmission to the UE in response to the Bearer Setup Request/Session Management Request message, a RRC

Connection Reconfiguration message to initiate the SRVCC handover; and decode, in response to transmission of the RRC Connection Reconfiguration message, a RRC Connection Reconfiguration Complete message from the UE, transmission of the Bearer Setup Response message in response to reception of the RRC Connection Reconfiguration Complete message. The processing circuitry may further be arranged to decode, from the UE after reception of the RRC Connection Reconfiguration Complete message and in response to transmission of the RRC Connection Reconfiguration message, a Session Management Response message. The processing circuitry may further be arranged to encode, for transmission to the MME in response to the Session Management Response message, a MME Session Management Response message.

[00143] Examples [00144] Example 1 is an apparatus of a Policy and Charging Rules Function (PCRF), the apparatus comprising: processing circuitry arranged to: decode Internet Protocol Multimedia System (IMS) service information for media from a Proxy Call Session Control Function (P-CSCF), the IMS service information comprising codec information of a user equipment (UE); set, based on the codec information in the IMS service information, a Maximum Packet Loss Rate for uplink and downlink communications between the UE and an evolved NodeB (eNB) serving the UE; and encode a Policy and Charging Control (PCC) rule for the media for transmission to a Policy and Charging Enforcement Function (PCEF) in a packet data network gateway (PDN GW), the PCC rule comprising the Maximum Packet Loss Rate for uplink and downlink communications; and a memory configured to store the Maximum Packet Loss Rate.

[00145] In Example 2, the subject matter of Example 1 includes, wherein: the media is voice media.

[00146] In Example 3, the subject matter of Examples 1-2 includes, wherein the processing circuitry is further arranged to: select the Maximum Packet Loss Rate from Maximum Packet Loss Rates for different codec modes.

[00147] In Example 4, the subject matter of Example 3 includes, wherein: the Maximum Packet Loss Rate corresponds to a most robust codec mode or a least robust codec mode.

[00148] In Example 5, the subject matter of Examples 1-4 includes, wherein the processing circuitry is further arranged to: select the Maximum Packet Loss Rate for uplink communications and downlink communications from a plurality of pairs of a Maximum Packet Loss Rate for uplink

communications and downlink communications for different codec modes.

[00149] In Example 6, the subject matter of Examples 1-5 includes, wherein: the IMS service information initiates one of dedicated bearer activation or bearer modification of a bearer, and the processing circuitry is further arranged to, in response to reception of the IMS service information, initiate IP Connectivity Access Network (CAN) Session Modification of the dedicated bearer activation procedure and encode for transmission a PCC decision provision message to the PDN GW if dynamic PCC is deployed, the PCC decision provision message configured to request a particular quality of service (QoS).

[00150] In Example 7, the subject matter of Example 6 includes, wherein: the PCC decision provision message indicates that at least one of location or time zone information of the UE is to be provided to the PCRF.

[00151] In Example 8, the subject matter of Example 7 includes, wherein the processing circuitry is further arranged to: decode, from the PDN GW in response to transmission of the PCC decision provision message, an indication whether a PCC decision is able to be enforced, the indication comprising the at least one of location or time zone information of the UE.

[00152] In Example 9, the subject matter of Examples 6-8 includes, wherein: the bearer is a QoS Class Identifier (QCI)=1 bearer.

[00153] In Example 10, the subject matter of Examples 1-9 includes, wherein: the processing circuitry comprises a Gx interface through which the

PCRF communicates with the PDN GW.

[00154] Example 11 is a computer-readable storage medium that stores instructions for execution by one or more processors of a Policy and Charging Rules Function (PCRF), the one or more processors to configure the UE to, when the instructions are executed: receive Internet Protocol Multimedia System (IMS) service information for media from a Proxy Call Session Control Function (P-CSCF), the IMS service information comprising codec information of a user equipment (UE); determine, based on the codec information in the IMS service information, a Maximum Packet Loss Rate for uplink and downlink

communications of the UE; and transmit a Policy and Charging Control (PCC) rule for the media to a Policy and Charging Enforcement Function (PCEF) in a packet data network gateway (PDN GW), the PCC rule comprising the

Maximum Packet Loss Rate for uplink and downlink communications.

[00155] In Example 12, the subject matter of Example 11 includes, wherein: the media is voice media.

[00156] In Example 13, the subject matter of Examples 1 1-12 includes, wherein the instructions further configure the one or more processors to configure the PCRF to: select the Maximum Packet Loss Rate from Maximum Packet Loss Rates for different codec modes.

[00157] In Example 14, the subject matter of Example 13 includes, wherein: the Maximum Packet Loss Rate corresponds to a most robust codec mode or a least robust codec mode.

[00158] In Example 15, the subject matter of Examples 11-14 includes, wherein the instructions further configure the one or more processors to configure the PCRF to: select the Maximum Packet Loss Rate for uplink communications and downlink communications from a plurality of pairs of a Maximum Packet Loss Rate for uplink communications and downlink communications for different codec modes.

[00159] In Example 16, the subject matter of Examples 1 1-15 includes, wherein: the IMS service information initiates one of dedicated bearer activation or bearer modification of a bearer, and the instructions further configure the one or more processors to configure the PCRF to, in response to reception of the IMS service information, initiate IP Connectivity Access Network (CAN) Session Modification of the dedicated bearer activation procedure and encode for transmission a PCC decision provision message to the PDN GW if dynamic PCC is deployed, the PCC decision provision message configured to request a particular quality of service (QoS).

[00160] In Example 17, the subject matter of Example 16 includes, wherein: the PCC decision provision message indicates that at least one of location or time zone information of the UE is to be provided to the PCRF.

[00161] In Example 18, the subject matter of Example 17 includes, wherein the instructions further configure the one or more processors to configure the PCRF to: receive, from the PDN GW in response to transmission of the PCC decision provision message, an indication whether a PCC decision is able to be enforced, the indication comprising the at least one of location or time zone information of the UE.

[00162] Example 19 is an apparatus of an evolved NodeB (eNB), the apparatus comprising: a memory; and processing circuitry arranged to: decode a measurement report from a user equipment (UE), the measurement report comprising a measurement of at least one parameter; determine, based on the at least one parameter, whether to execute Single Radio Voice Call Continuity (SRVCC) handover of the UE, a determination of whether to execute the SRVCC handover dependent on a SRVCC threshold, the SRVCC threshold dependent on a codec type used by the UE, the SRVCC threshold and codec type stored in the memory; and initiate SRVCC handover in response to the determination to execute the SRVCC handover.

[00163] In Example 20, the subject matter of Example 19 includes, wherein the processing circuitry is further arranged to: set, based on the codec type, a Maximum Packet Loss Rate for uplink and downlink communications with the UE.

[00164] Example 21 is at least one machine-readable medium including instructions that, when executed by processing circuitry, cause the processing circuitry to perform operations to implement of any of Examples 1-20.

[00165] Example 22 is an apparatus comprising means to implement of any of Examples 1-20.

[00166] Example 23 is a system to implement of any of Examples 1-20.

[00167] Example 24 is a method to implement of any of Examples 1-20.

[00168] Although an embodiment has been described with reference to specific example embodiments, it will be evident that various modifications and changes may be made to these embodiments without departing from the broader scope of the present disclosure. Accordingly, the specification and drawings are to be regarded in an illustrative rather than a restrictive sense. The

accompanying drawings that form a part hereof show, by way of illustration, and not of limitation, specific embodiments in which the subject matter may be practiced. The embodiments illustrated are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be utilized and derived therefrom, such that structural and logical substitutions and changes may be made without departing from the scope of this disclosure. This Detailed Description, therefore, is not to be taken in a limiting sense, and the scope of various embodiments is defined only by the appended claims, along with the full range of equivalents to which such claims are entitled.

[00169] The Abstract of the Disclosure is provided to comply with 37

C.F.R. § 1.72(b), requiring an abstract that will allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.

Claims

CLAIMS What is claimed is:

1. An apparatus of a Policy and Charging Rules Function (PCRF), the apparatus comprising:

processing circuitry arranged to:

decode Internet Protocol Multimedia System (IMS) service information for media from a Proxy Call Session Control Function (P- CSCF), the IMS service information comprising codec information of a user equipment (UE);

set, based on the codec information in the IMS service information, a Maximum Packet Loss Rate for uplink and downlink communications between the UE and an evolved NodeB (eNB) serving the UE; and

encode a Policy and Charging Control (PCC) rule for the media for transmission to a Policy and Charging Enforcement Function (PCEF) in a packet data network gateway (PDN GW), the PCC rule comprising the Maximum Packet Loss Rate for uplink and downlink

communications; and

a memory configured to store the Maximum Packet Loss Rate.

2. The apparatus of claim 1, wherein:

the media is voice media.

3. The apparatus of claim 1 or 2, wherein the processing circuitry is further arranged to:

select the Maximum Packet Loss Rate from Maximum Packet Loss Rates for different codec modes.

4. The apparatus of claim 3, wherein:

the Maximum Packet Loss Rate corresponds to a most robust codec mode or a least robust codec mode.

5. The apparatus of claim 1 or 2, wherein the processing circuitry is further arranged to:

select the Maximum Packet Loss Rate for uplink communications and downlink communications from a plurality of pairs of a Maximum Packet Loss Rate for uplink communications and downlink communications for different codec modes.

6. The apparatus of claim 1 or 2, wherein:

the IMS service information initiates one of dedicated bearer activation or bearer modification of a bearer, and

the processing circuitry is further arranged to, in response to reception of the IMS service information, initiate IP-Connectivity Access Network (CAN) Session Modification of the dedicated bearer activation procedure and encode for transmission a PCC decision provision message to the PDN GW if dynamic PCC is deployed, the PCC decision provision message configured to request a particular quality of service (QoS).

7. The apparatus of claim 6, wherein:

the PCC decision provision message indicates that at least one of location or time zone information of the UE is to be provided to the PCRF.

8. The apparatus of claim 7, wherein the processing circuitry is further arranged to:

decode, from the PDN GW in response to transmission of the PCC decision provision message, an indication whether a PCC decision is able to be enforced, the indication comprising the at least one of location or time zone information of the UE.

9. The apparatus of claim 6, wherein:

the bearer is a QoS Class Identifier (QCI)=1 bearer.

10. The apparatus of claim 1 or 2, wherein: the processing circuitry comprises a Gx interface through which the PCRF communicates with the PDN GW.

11. A computer-readable storage medium that stores instructions for execution by one or more processors of a Policy and Charging Rules Function (PCRF), the one or more processors to configure the UE to, when the instructions are executed:

receive Internet Protocol Multimedia System (IMS) service information for media from a Proxy Call Session Control Function (P-CSCF), the IMS service information comprising codec information of a user equipment (UE); determine, based on the codec information in the IMS service information, a Maximum Packet Loss Rate for uplink and downlink

communications of the UE; and

transmit a Policy and Charging Control (PCC) rule for the media to a Policy and Charging Enforcement Function (PCEF) in a packet data network gateway (PDN GW), the PCC rule comprising the Maximum Packet Loss Rate for uplink and downlink communications.

12. The medium of claim 11, wherein:

the media is voice media.

13. The medium of claim 11 or 12, wherein the instructions further configure the one or more processors to configure the PCRF to:

select the Maximum Packet Loss Rate from Maximum Packet Loss Rates for different codec modes.

14. The medium of claim 13, wherein:

the Maximum Packet Loss Rate corresponds to a most robust codec mode or a least robust codec mode.

15. The medium of claim 11 or 12, wherein the instructions further configure the one or more processors to configure the PCRF to: select the Maximum Packet Loss Rate for uplink communications and downlink communications from a plurality of pairs of a Maximum Packet Loss Rate for uplink communications and downlink communications for different codec modes.

16. The medium of claim 1 1 or 12, wherein:

the IMS service information initiates one of dedicated bearer activation or bearer modification of a bearer, and

the instructions further configure the one or more processors to configure the PCRF to, in response to reception of the IMS service information, initiate IP-Connectivity Access Network (CAN) Session Modification of the dedicated bearer activation procedure and encode for transmission a PCC decision provision message to the PDN GW if dynamic PCC is deployed, the PCC decision provision message configured to request a particular quality of service (QoS).

17. The medium of claim 16, wherein:

the PCC decision provision message indicates that at least one of location or time zone information of the UE is to be provided to the PCRF.

18. The medium of claim 17, wherein the instructions further configure the one or more processors to configure the PCRF to:

receive, from the PDN GW in response to transmission of the PCC decision provision message, an indication whether a PCC decision is able to be enforced, the indication comprising the at least one of location or time zone information of the UE.

An apparatus of an evolved NodeB (eNB), the apparatus comprising: a memory; and

processing circuitry arranged to:

decode a measurement report from a user equipment (UE), the measurement report comprising a measurement of at least one parameter; determine, based on the at least one parameter, whether to execute Single Radio Voice Call Continuity (SRVCC) handover of the UE, a determination of whether to execute the SRVCC handover dependent on a SRVCC threshold, the SRVCC threshold dependent on a codec type used by the UE, the SRVCC threshold and codec type stored in the memory; and

initiate SRVCC handover in response to the determination to execute the SRVCC handover. 20. The apparatus of claim 19, wherein the processing circuitry is further arranged to:

set, based on the codec type, a Maximum Packet Loss Rate for uplink and downlink communications with the UE.