Methods, architectures, apparatuses and systems for early notification of dropped packets in communication networks

Abstract

A method implemented in a network element is described. The method may include (i) receiving a QoS profile, (2) receiving a message including a first data packet that is not a null packet and a second data packet that is a null packet, (3) determining whether the network element begins transmitting content of the message to a wireless transmit / receive unit (WTRU) before or after a first duration has elapsed after the message has been received, (4) determining whether the network element begins transmitting the content of the message before or after a second duration has elapsed after the message has been received, and (5) transmitting only the second data packet that is the null packet to the WTRU based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed.

Description

METHODS, ARCHITECTURES, APPARATUSES AND SYSTEMS FOR EARLY NOTIFICATION OF DROPPED PACKETS IN COMMUNICATION NETWORKSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of US Patent Application No. 63 / 547,009 filed November 02, 2023, which is incorporated herein by reference in its entirety.TECHNICAL FIELD

[0002] This disclosure pertains to procedures, methods, architectures, apparatus, systems, devices, and computer program products for, and / or directed to providing early notification to a network node, e.g., a wireless transmit / receive unit (WTRU), of a dropped packet in a wireless network.BACKGROUND

[0003] There may be cases in which the radio access network (RAN) may decide to discard packets. In these cases, the receiver may be in a state where it may wait for the packet for a certain amount of time before determining that the packet will not be received before proceeding, for example, to error concealment. Embodiments described herein have been designed with the foregoing in mind.BRIEF SUMMARY

[0004] Methods, architectures, apparatuses, and systems directed to early notification of dropped packets are described herein. In an embodiment, a method implemented in a network element is described. The method may include receiving a quality of service (QoS) profile indicating a delay budget and a notification delay budget. The method may include receiving a message comprising a first data packet that may not be a null packet and a second data packet that may be a null packet. The method may include determining whether the network element begins transmitting content of the message to a WTRU before or after a first duration has elapsed after the message has been received, the first duration being based on the delay budget. The method may include determining whether the network element begins transmitting the content of the message before or after a second duration has elapsed after the message has been received, the second duration being based on the notification delay budget. The method may include transmitting only the second data packet that may be the null packet to the WTRU based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed. The method may include discarding both the first data packet and the second data packet based on the transmitting not having begun after the second duration having elapsed.

[0005] In an embodiment, a network element is described. The network element may comprise circuitry including any of a transmitter, a receiver, a processor, and a memory. The network element may be configured to receive a QoS profile indicating a delay budget and a notification delay budget. The network element may be configured to receive a message comprising a first data packet that may not be a null packet and a second data packet that may be a null packet. The network element may be configured to determine whether the network element begins transmitting content of the message to a WTRU before or after a first duration has elapsed after the message has been received, the first duration being based on the delay budget. The network element may be configured to determine whether the network element begins transmitting the content of the message before or after a second duration has elapsed after the message has been received, the second duration being based on the notification delay budget. The network element may be configured to transmit only the second data packet that may be the null packet to the WTRU based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed. The network element may be configured to discard both the first data packet and the second data packet based on the transmitting not having begun after the second duration having elapsed.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] A more detailed understanding may be had from the detailed description below, given by way of example in conjunction with the drawings appended hereto. Figures in such drawings, like the detailed description, are exemplary. As such, the Figures and the detailed description are not to be considered limiting, and other equally effective examples are possible and likely. Furthermore, like reference numerals ("ref.") in the Figures ("FIGs.") indicate like elements, and wherein:

[0007] FIG. 1 A is a system diagram illustrating an example communications system;

[0008] FIG. IB is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1 A;

[0009] FIG. 1C is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A;

[0010] FIG. ID is a system diagram illustrating a further example RAN and a further example CN that may be used within the communications system illustrated in FIG. 1 A;[OH] FIG. 2 is signal flow diagram of an example procedure for application server (AS) transmission of null packets; and

[0012] FIG. 3 is a diagram illustrating an example method for early notifications of dropped packets.DETAILED DESCRIPTION

[0013] In the following detailed description, numerous specific details are set forth to provide a thorough understanding of embodiments and / or examples disclosed herein. However, it will be understood that such embodiments and examples may be practiced without some or all of the specific details set forth herein. In other instances, well-known methods, procedures, components, and circuits have not been described in detail, so as not to obscure the following description. Further, embodiments and examples not specifically described herein may be practiced in lieu of, or in combination with, the embodiments and other examples described, disclosed, or otherwise provided explicitly, implicitly and / or inherently (collectively "provided") herein.EXAMPLE COMMUNICATION SYSTEMS

[0014] FIG. 1 A is a diagram illustrating an example communications system 100 in which one or more disclosed embodiments may be implemented. The communications system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communications system 100 may enable multiple wireless users to access such content through the sharing of system resources, including wireless bandwidth. For example, the communications systems 100 may employ one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), zero-tail unique-word DFT-Spread OFDM (ZT UW DTS-s OFDM), unique word OFDM (UW-OFDM), resource block-filtered OFDM, filter bank multicarrier (FBMC), and the like.

[0015] As shown in FIG. 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, though it will be appreciated that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wirelessenvironment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or a “STA”, may be configured to transmit and / or receive wireless signals and may include a user equipment (UE), a mobile station, a fixed or mobile subscriber unit, a subscription-based unit, a pager, a cellular telephone, a personal digital assistant (PDA), a smartphone, a laptop, a netbook, a personal computer, a wireless sensor, a hotspot or Mi-Fi device, an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. Any of the WTRUs 102a, 102b, 102c and 102d may be interchangeably referred to as a UE.

[0016] The communications systems 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, such as the CN 106 / 115, the Internet 110, and / or the other networks 112. By way of example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a Home Node B, a Home eNode B, a gNB, a NR NodeB, a site controller, an access point (AP), a wireless router, and the like. While the base stations 114a, 114b are each depicted as a single element, it will be appreciated that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0017] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), such as a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as a cell (not shown). These frequencies may be in licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for a wireless service to a specific geographical area that may be relatively fixed or that may change over time. The cell may further be divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one for each sector of the cell. In an embodiment, the base station 114a may employ multiple-input multiple output (MIMO) technology and may utilize multiple transceivers for each sector ofthe cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0018] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0019] More specifically, as noted above, the communications system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 116 using wideband CDMA (WCDMA). WCDMA may include communication protocols such as High-Speed Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High-Speed Downlink Packet Access (HSDPA) and / or High-Speed Uplink Packet Access (HSUPA).

[0020] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE- Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0021] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR Radio Access, which may establish the air interface 116 using New Radio (NR).

[0022] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement LTE radio access and NR radio access together, for instance using dual connectivity (DC) principles. Thus, the air interface utilized by WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., an eNB and a gNB).

[0023] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement radio technologies such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 IX, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), GSM EDGE (GERAN), and the like.

[0024] The base station 114b in FIG. 1A may be a wireless router, Home Node B, Home eNode B, or access point, for example, and may utilize any suitable RAT for facilitating wireless connectivity in a localized area, such as a place of business, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, and the like. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellularbased RAT (e g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR etc.) to establish a picocell or femtocell. As shown in FIG. 1 A, the base station 114b may have a direct connection to the Internet 110. Thus, the base station 114b may not be required to access the Internet 110 via the CN 106 / 115.

[0025] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, applications, and / or voice over internet protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have varying quality of service (QoS) requirements, such as differing throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. The CN 106 / 115 may provide call control, billing services, mobile location-based services, pre-paid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions, such as user authentication. Although not shown in FIG. 1A, it will be appreciated that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs that employ the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may be utilizing a NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) employing a GSM, UMTS, CDMA 2000, WiMAX, E-UTRA, or WiFi radio technology.

[0026] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or the other networks 112. The PSTN 108 mayinclude circuit-switched telephone networks that provide plain old telephone service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as the transmission control protocol (TCP), user datagram protocol (UDP) and / or the internet protocol (IP) in the TCP / IP internet protocol suite. The networks 112 may include wired and / or wireless communications networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs, which may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0027] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers for communicating with different wireless networks over different wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with the base station 114a, which may employ a cellular-based radio technology, and with the base station 114b, which may employ an IEEE 802 radio technology.

[0028] FIG. IB is a system diagram illustrating an example WTRU 102. As shown in FIG. IB, the WTRU 102 may include a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a global positioning system (GPS) chipset 136, and / or other peripherals 138, among others. It will be appreciated that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0029] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. While FIG. IB depicts the processor 118 and the transceiver 120 as separate components, it will be appreciated that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0030] The transmit / receive element 122 may be configured to transmit signals to, or receive signals from, abase station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive IR, UV, or visible light signals, for example. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be appreciated that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0031] Although the transmit / receive element 122 is depicted in FIG. IB as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0032] The transceiver 120 may be configured to modulate the signals that are to be transmitted by the transmit / receive element 122 and to demodulate the signals that are received by the transmit / receive element 122. As noted above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers for enabling the WTRU 102 to communicate via multiple RATs, such as NR and IEEE 802.11, for example.

[0033] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or organic light-emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. In addition, the processor 118 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 130 and / or the removable memory 132. The non-removable memory 130 may include randomaccess memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 132 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other embodiments, the processor 118 may access information from, and store data in, memory that is not physically located on the WTRU 102, such as on a server or a home computer (not shown).

[0034] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to the other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.

[0035] The processor 118 may also be coupled to the GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding the current location of the WTRU 102. In addition to, or in lieu of, the information from the GPS chipset 136, the WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) and / or determine its location based on the timing of the signals being received from two or more nearby base stations. It will be appreciated that the WTRU 102 may acquire location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0036] The processor 118 may further be coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photographs and / or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a Virtual Reality and / or Augmented Reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, the sensors may be one or more of a gyroscope, an accelerometer, a hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor; a geolocation sensor; an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0037] The WTRU 102 may include a full duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for both the uplink (e.g., for transmission) and downlink (e.g., for reception) may be concurrent and / or simultaneous. The full duplex radio may include an interference management unit to reduce and or substantially eliminate self-interference via either hardware (e.g., a choke) or signal processingvia a processor (e.g., a separate processor (not shown) or via processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for which transmission and reception of some or all of the signals (e.g., associated with particular subframes for either the uplink (e.g., for transmission) or the downlink (e.g., for reception)).

[0038] FIG. 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As noted above, the RAN 104 may employ an E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0039] The RAN 104 may include eNode-Bs 160a, 160b, 160c, though it will be appreciated that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO technology. Thus, the eNode-B 160a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a.

[0040] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), and the like. As shown in FIG. 1C, the eNode-Bs 160a, 160b, 160c may communicate with one another over an X2 interface.

[0041] The CN 106 shown in FIG. 1C may include a mobility management entity (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements are depicted as part of the CN 106, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0042] The MME 162 may be connected to each of the eNode-Bs 160a, 160b, 160c in the RAN 104 via an SI interface and may serve as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, bearer activation / deactivation, selecting a particular serving gateway during an initial attach of the WTRUs 102a, 102b, 102c, and the like. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) that employ other radio technologies, such as GSM and / or WCDMA.

[0043] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via the SI interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as anchoring user planes during inter-eNode B handovers, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing contexts of the WTRUs 102a, 102b, 102c, and the like.

[0044] The SGW 164 may be connected to the PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0045] The CN 106 may facilitate communications with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communications between the WTRUs 102a, 102b, 102c and traditional land-line communications devices. For example, the CN 106 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. In addition, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers.

[0046] Although the WTRU is described in FIGS. 1A-1D as a wireless terminal, it is contemplated that in certain representative embodiments that such a terminal may use (e.g., temporarily or permanently) wired communication interfaces with the communication network.

[0047] In representative embodiments, the other network 112 may be a WLAN.

[0048] A WLAN in Infrastructure Basic Service Set (BSS) mode may have an Access Point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have an access or an interface to a Distribution System (DS) or another type of wired / wireless network that carries traffic in to and / or out of the BSS. Traffic to STAs that originates from outside the BSS may arrive through the AP and may be delivered to the STAs. Traffic originating from STAs to destinations outside the BSS may be sent to the AP to be delivered to respective destinations. Traffic between STAs within the BSS may be sent through the AP, for example, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. The traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. The peer-to-peer traffic may be sent between (e.g.,directly between) the source and destination STAs with a direct link setup (DLS). In certain representative embodiments, the DLS may use an 802. l ie DLS or an 802. l lz tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may not have an AP, and the STAs (e.g., all of the STAs) within or using the IBSS may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an “ad-hoc” mode of communication.

[0049] When using the 802.1 lac infrastructure mode of operation or a similar mode of operations, the AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be a fixed width (e.g., 20 MHz wide bandwidth) or a dynamically set width via signaling. The primary channel may be the operating channel of the BSS and may be used by the STAs to establish a connection with the AP. In certain representative embodiments, Carrier Sense Multiple Access with Collision Avoidance (CSMA / CA) may be implemented, for example in in 802.11 systems. For CSMA / CA, the STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected and / or determined to be busy by a particular STA, the particular STA may back off. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0050] High Throughput (HT) STAs may use a 40 MHz wide channel for communication, for example, via a combination of the primary 20 MHz channel with an adjacent or nonadj acent 20 MHz channel to form a 40 MHz wide channel.

[0051] Very High Throughput (VHT) STAs may support 20MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. The 40 MHz, and / or 80 MHz, channels may be formed by combining contiguous 20 MHz channels. A 160 MHz channel may be formed by combining 8 contiguous 20 MHz channels, or by combining two non-contiguous 80 MHz channels, which may be referred to as an 80+80 configuration. For the 80+80 configuration, the data, after channel encoding, may be passed through a segment parser that may divide the data into two streams. Inverse Fast Fourier Transform (IFFT) processing, and time domain processing, may be done on each stream separately. The streams may be mapped on to the two 80 MHz channels, and the data may be transmitted by a transmitting STA. At the receiver of the receiving STA, the above described operation for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0052] Sub 1 GHz modes of operation are supported by 802.1 laf and 802.11 ah. The channel operating bandwidths, and carriers, are reduced in 802.1 laf and 802.1 lah relative to those usedin 802.1 In, and 802.1 lac. 802.11af supports 5 MHz, 10 MHz and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11 ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah may support Meter Type Control / Machine-Type Communications, such as MTC devices in a macro coverage area. MTC devices may have certain capabilities, for example, limited capabilities including support for (e.g., only support for) certain and / or limited bandwidths. The MTC devices may include a battery with a battery life above a threshold (e.g., to maintain a very long battery life).

[0053] WLAN systems, which may support multiple channels, and channel bandwidths, such as 802.1 In, 802.1 lac, 802.1 laf, and 802.1 lah, include a channel which may be designated as the primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by a STA, from among all STAs in operating in a BSS, which supports the smallest bandwidth operating mode. In the example of 802.1 lah, the primary channel may be 1 MHz wide for STAs (e.g., MTC type devices) that support (e.g., only support) a 1 MHz mode, even if the AP, and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or Network Allocation Vector (NAV) settings may depend on the status of the primary channel. If the primary channel is busy, for example, due to a STA (which supports only a 1 MHz operating mode), transmitting to the AP, the entire available frequency bands may be considered busy even though a majority of the frequency bands remains idle and may be available.

[0054] In the United States, the available frequency bands, which may be used by 802.1 lah, are from 902 MHz to 928 MHz. In Korea, the available frequency bands are from 917.5 MHz to 923.5 MHz. In Japan, the available frequency bands are from 916.5 MHz to 927.5 MHz. The total bandwidth available for 802.1 lah is 6 MHz to 26 MHz depending on the country code.

[0055] FIG. ID is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As noted above, the RAN 113 may employ an NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0056] The RAN 113 may include gNBs 180a, 180b, 180c, though it will be appreciated that the RAN 113 may include any number of gNBs while remaining consistent with anembodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the WTRUs 102a, 102b, 102c. Thus, the gNB 180a, for example, may use multiple antennas to transmit wireless signals to, and / or receive wireless signals from, the WTRU 102a. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation technology. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on unlicensed spectrum while the remaining component carriers may be on licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement Coordinated Multi-Point (CoMP) technology. For example, WTRU 102a may receive coordinated transmissions from gNB 180a and gNB 180b (and / or gNB 180c).

[0057] The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may vary for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using subframe or transmission time intervals (TTIs) of various or scalable lengths (e.g., containing varying number of OFDM symbols and / or lasting varying lengths of absolute time).

[0058] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non- standalone configuration. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c without also accessing other RANs (e.g., such as eNode-Bs 160a, 160b, 160c). In the standalone configuration, WTRUs 102a, 102b, 102c may utilize one or more of gNBs 180a, 180b, 180c as a mobility anchor point. In the standalone configuration, WTRUs 102a, 102b, 102c may communicate with gNBs 180a, 180b, 180c using signals in an unlicensed band. In a non-standalone configuration WTRUs 102a, 102b, 102c may communicate with / connect to gNBs 180a, 180b, 180c while also communicating with / connecting to another RAN such as eNode-Bs 160a, 160b, 160c. For example, WTRUs 102a, 102b, 102c may implement DC principles to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode- Bs 160a, 160b, 160c substantially simultaneously. In the non-standalone configuration, eNode-Bs 160a, 160b, 160c may serve as a mobility anchor for WTRUs 102a, 102b, 102c and gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for servicing WTRUs 102a, 102b, 102c.

[0059] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the uplink (UL) and / or downlink (DL), support of network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data towards User Plane Function (UPF) 184a, 184b, routing of control plane information towards Access and Mobility Management Function (AMF) 182a, 182b and the like. As shown in FIG. ID, the gNBs 180a, 180b, 180c may communicate with one another over an Xn interface.

[0060] The CN 115 shown in FIG. ID may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. While each of the foregoing elements are depicted as part of the CN 115, it will be appreciated that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0061] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may serve as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, support for network slicing (e.g., handling of different PDU (Protocol Data Unit) sessions with different requirements), selecting a particular SMF 183a, 183b, management of the registration area, termination of non-access stratum (NAS) signaling, mobility management, and the like. Network slicing may be used by the AMF 182a, 182b in order to customize CN support for WTRUs 102a, 102b, 102c based on the types of services being utilized by WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases such as services relying on ultra-reliable low latency (URLLC) access, services relying on enhanced massive mobile broadband (eMBB) access, services for machine type communication (MTC) access, and / or the like. The AMF 182a, 182b may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that employ other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0062] The SMF 183a, 183b may be connected to an AMF 182a, 182b in the CN 115 via an Ni l interface. The SMF 183a, 183b may also be connected to a UPF 184a, 184b in the CN115 via an N4 interface. The SMF 183a, 183b may select and control the UPF 184a, 184b and configure the routing of traffic through the UPF 184a, 184b. The SMF 183 a, 183b may perform other functions, such as managing and allocating UE IP address, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notifications, and the like. A PDU session type may be IP-based, non-IP based, Ethernet-based, and the like.

[0063] The UPF 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPF 184a, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, and the like.

[0064] The CN 115 may facilitate communications with other networks. For example, the CN 115 may include, or may communicate with, an IP gateway (e.g., an IP multimedia subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. In addition, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to the other networks 112, which may include other wired and / or wireless networks that are owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to a local Data Network (DN) 185a, 185b through the UPF 184a, 184b via the N3 interface to the UPF 184a, 184b and an N6 interface between the UPF 184a, 184b and the DN 185a, 185b.

[0065] In view of Figs. 1A-1D, and the corresponding description of Figs. 1A-1D, one or more, or all, of the functions described herein with regard to one or more of WTRU 102a-d, Base Station 114a-b, eNode-B 160a-c, MME 162, SGW 164, PGW 166, gNB 180a-c, AMF 182a-b, UPF 184a-b, SMF 183a-b, DN 185a-b, and / or any other device(s) described herein, may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more, or all, of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0066] The emulation devices may be designed to implement one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform the one or more, or all, functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network inorder to test other devices within the communication network. The one or more emulation devices may perform the one or more, or all, functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for purposes of testing and / or may performing testing using over-the-air wireless communications.

[0067] The one or more emulation devices may perform the one or more, including all, functions while not being implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing scenario in a testing laboratory and / or a non-deployed (e.g., testing) wired and / or wireless communication network in order to implement testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communications via RF circuitry (e.g., which may include one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0068] Throughout embodiments described herein the terms "base station", "network", and "gNB", collectively "the network" may be used interchangeably to designate any network element such as e.g., a network element acting as a serving base station. Embodiments described herein are not limited to gNBs and are applicable to any other type of base stations.

[0069] Throughout embodiments described herein the terms "node" and "network element" may be used interchangeably to refer to an apparatus of the communication network running communication functions.

[0070] For the sake of clarity, satisfying, failing to satisfy a condition, and configuring condition parameter(s) are described throughout embodiments described herein as relative to a threshold (e.g., greater, or lower than) a (e.g., threshold) value, configuring the (e.g., threshold) value, etc. For example, satisfying a condition may be described as being above a (e.g., threshold) value, and failing to satisfy a condition may be described as being below a (e.g., threshold) value. Embodiments described herein are not limited to threshold-based conditions. Any kind of other condition and parameter(s) (such as e.g., belonging or not belonging to a range of values) may be applicable to embodiments described herein.

[0071] Throughout embodiments described herein, (e.g., configuration) information may be described as received by a WTRU from the network, for example, through system information or via any kind of protocol message. Although not explicitly mentioned throughout embodiments described herein, the same (e.g., configuration) information may be pre-configured in the WTRU (e.g., via any kind of pre-configuration methods such as e.g., via factory settings), such that this (e.g., configuration) information may be used by the WTRU without being received from the network.

[0072] Throughout embodiments described herein, the expression "the WTRU may be configured with a set of parameters" is equivalent or may be used interchangeably with "the WTRU may receive configuration information (e.g., from another network element (e.g., gNB)) indicating a set of parameters". Throughout embodiments described herein, the expressions "the WTRU may report something", and "the WTRU may be configured to report something", is equivalent or may be used interchangeably with "the WTRU may transmit (e.g., reporting) information indicating something". Throughout embodiments described herein, the expression "the WTRU may provide ( / be provided) with a set of parameters ( / something)" is equivalent or may be used interchangeably with "the WTRU may transmit ( / receive) information indicating a set of parameters ( / something)".

[0073] In embodiments described herein, ‘a’ and ‘an’ and similar phrases are to be interpreted as ‘one or more’ and ‘at least one’. Similarly, any term which ends with the suffix ‘(s)’ is to be interpreted as ‘one or more’ and ‘at least one’. The term ‘may’ is to be interpreted as ‘may, for example’.

[0074] A symbol 7’ (e.g., forward slash) may be used herein to represent ‘and / or’, where for example, ‘A / B’ may imply ‘A and / or B’.

[0075] In embodiments described herein, the terms “dropping a packet”, “discarding a packet” and “not transmitting a packet” may be used interchangeably to refer to a process where it is determined to drop / discard / remove a packet that was to be transmitted and that will no longer be transmitted.

[0076] In embodiments described herein, the terms “data packet” and “non-null data packet” collectively “packet” may be used interchangeably to refer to any kind of non-null packet.PDU Set Marking in RTP Header Extensions

[0077] Reference [5] describes a general mechanism for defining real-time transport protocol (RTP) header extensions.

[0078] Reference [4] describes RTP header extension for the marking of PDU sets and end of bursts. The header extension carries information such as any of a local identifier, an end of PDU set indication, an end of data burst indication, a PDU set importance indication, a PDU set sequence number, a PDU set sequence number within a PDU set, and a PDU set size.Error Concealment of Application Layer Traffic

[0079] In some scenarios, when some data units of a certain stream are lost, the application may try to recover or conceal the data units that are lost using error concealment techniques. For instance, the application server may send traffic to the WTRU, and the WTRU may use the received data units to replace or try to estimate the lost data units.

[0080] For an audio stream, one exemplary error concealment technique relies on inserting silence (or data units of content zero) in place of the lost data units / packets. Another example includes replacement methods, interleaving techniques, and interpolation-based repair methods.

[0081] In another exemplary technique relating to video content, referred to as freeze frame, one lost packet of the frame may be replaced by a previous frame.

[0082] Another approach relating to video content involves inter frame interpolation. In inter frame interpolation, if a frame is lost, interpolation of pixels of previous frames of the same area can be used to recreate the lost information.Packet Dropping

[0083] There may be cases in which the RAN may decide (e.g., determine) to discard packets. In these cases, the receiver may be in a state where it may wait for the packet for a (e.g., certain) amount of time before determining that the packet may not be received. Once the receiver determines that the packet may not be received, the receiver may proceed processing other packets and may use error concealment techniques to account for the discarded packet. The receiver may use a timeout value to determine that a packet may have been discarded. Embodiments described herein may enable a receiver to more quickly recognize that a packet may have been discarded. Currently, the 5G system provides no mechanism to assist the WTRU in quickly detecting that a packet may have been discarded. The WTRU application may rely on a timeout to determine that a packet may be discarded.Overview

[0084] A WTRU may receive a notification from the network (e.g., indicating) that a packet has been dropped. In an example, the notification that a packet has been dropped may be smaller (e.g., less data) than the packet that was dropped. By sending such a notification to the WTRU, the WTRU application may be able to more quickly detect that a packet has been discarded and be able to process downlink packets more quickly.

[0085] For example, a null packet may be sent to a WTRU in place of a packet carrying data.For example, the null packet may be a packet with a header that may include information about the packet that was dropped. For instance, the information about the packet that was dropped may include one or more of (a) the size of the packet that was dropped, (b) the PDU set sequence number (PSSN) of the packet that was dropped, (c) the PDU sequence number within a PDU set (PSN) of the packet that was dropped, and (d) the PDU set size (PS Size) of the PDU set that the dropped packet may belong to. The payload of the null packet may be empty. The packet carrying data may be the packet that was dropped. The information about the packet that was dropped may (e.g., also) include the synchronization source (SSRC) of the packet and the sequence number of the packet.Application Server Provided Null Packets

[0086] In an example, a new RTP header extension may be defined. The new header extension may include: an indication that a null packet may be appended to the end of the PDU and / or an indication of the size of the null packet.

[0087] Embodiments are described herein with RTP and RTP header extensions as an example of transport protocol. Embodiments described herein are not limited to RTP packets and are applicable to any kind of transport protocol and header extensions.

[0088] For example, an application server (AS) may transmit a PDU that may carry two RTP packets. The header of the first RTP packet may indicate any of the presence and the size of the second RTP packet in the PDU. The content of the second RTP packet may be relatively smaller than the first RTP packet.

[0089] When the user plane function (UPF) receives a PDU, the UPF may detect, in the RTP header, that there may be a null packet appended to the end of the PDU. The UPF may send the PDU to the RAN node in a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message. The GTP-U message may indicate that the PDU may carry two RTP packets, that one packet may be a null packet, and may indicate the size of the null packet.

[0090] The RAN node may determine which of the two RTP packets to transmit to the WTRU. For example, the RAN node may determine to transmit the null packet if there is a congestion situation. Otherwise, the RAN node may determine to transmit the first packet which is not a null packet. The packet that is not transmitted may be discarded.

[0091] In another example, when the RAN node receives a GTP-U message indicating that the GTP-U message may include an RTP packet and an associated null packet, the RAN node may start two discard timers. The first discard timer may be configured with a relatively smallervalue. The second discard timer may be configured with a relatively larger value. If the RAN node is able to begin transmitting the packet to the WTRU before the first discard timer expires, the RAN node may transmit the RTP packet to the WTRU. If the RAN node is able to begin transmitting the packet to the WTRU (e.g., only) after the first discard timer expires but before the second discard timer expires, the RAN node may transmit the null packet to the WTRU. If the second discard timer expires before either the RTP packet or the null packet is transmitted to the WTRU, the RAN node may discard (e.g., both) the RTP packet and the null packet.

[0092] If the WTRU receives the null packet, processing of the data can continue and the receiver may more quickly know (e.g., be indicated) that the data was discarded (e.g., that only a null packet will be received). The header of the null packet may indicate how many bytes the null packet may represent. For example, the header of the null packet may indicate how many bytes the receiver may assume were discarded.

[0093] In another example, the RAN may send a message to the WTRU over the control plane indicating that null packet(s) may be imminent. For example, this message may be sent at the start of transmission so that the WTRU may anticipate dropped packet related information over the data plane (e.g., null packets), upon reception of the initial RTP packet or upon reception of a null packet. This message may include the information of the dropped packets (e.g., any of PSSN, PSN). This message may be sent, for example, as a radio resource control (RRC) message.

[0094] In another example, the RAN may send a message to the WTRU over the control plane indicating that a packet may have been dropped, such that the WTRU may not wait for that packet. For example, this message may be sent upon reception of a null packet. This message may include the information of the dropped packets (e.g., any of PSSN, PSN) so that the WTRU may be able to identify which packets the WTRU will not receive. This message may be sent, for example, as a RRC message.

[0095] An example procedure for an AS may transmit a null packet is shown in the exemplary signal flow diagram of FIG. 2.

[0096] As shown at 200, the AS 213 may negotiate with the WTRU 201 application client, e.g., via session description protocol (SDP) signalling, the parameters and format of the RTP header extension. For example, the AS 213 may agree with the WTRU application client to use an RTP header extension (HE) element to convey that the AS may use NULL packets to assist in indicating that a (e.g., certain) RTP packet may be discarded. The AS and WTRU applicationclient may negotiate an RTP HE element identifier for the extension element that may include / convey the NULL packets as well as the length of this extension element. For example, the WTRU application may use SDP to indicate to the AS that the WTRU application may understand a header extension that may indicate that a packet is a null packet and has been sent in place of a packet that is not a null packet. The SDP message exchanges between the WTRU application and the AS may (e.g., also) be used to negotiate delay values that may be used to configure packet delay budgets. For example, the WTRU application may indicate how long of a delay it may tolerate before a user’s quality of experience may be negatively impacted.

[0097] As shown at 210, the application function (AF) may invoke an Nnef AFsessionWithQoS Create service. The AF may provide PDU set QoS parameters to the network. The PDU set QoS parameters may include (e.g., both) a PDU set delay budget (PSDB) value and a notification PDU set delay budget (NPSDB) value.

[0098] The NPSDB may represent an upper bound for the amount of delay between the time the network determines to discard a packet and the network transmission of an associated null packet.

[0099] The AS may configure the PSDB and NPSDB based on the delay values that may have been provided by the WTRU application in the negotiation shown at 200.

[0100] The network exposure function (NEF) 211 may provide the PDU set QoS parameters to the policy control function (PCF) 209.

[0101] As shown at 220, the PCF may generate policy and charging control (PCC) rules and may provide (e.g., may send as shown at 221) the PCC rules to the session management function (SMF) 207. The PCC rules may include (e.g., both) the PSDB value and the NPSDB value.

[0102] As shown at 222, the SMF may configure QoS profile in the RAN node 203. As shown at 223, the SMF may send the QoS profile including (e.g., both) the PSDB value and an NPSDB value.

[0103] As shown at 230, the AS 213 may send extended reality and media services (XRM) traffic in the DL direction toward the WTRU 201 (e.g., via the UPF 205 and RAN 203). The AS 213 may determine that the information to transmit may be important for the WTRU application to receive and may decide to transmit (e.g., only) one RTP packet in the PDU and to not include a null packet in the PDU. In another example, the AS may determine that the WTRU application may be capable of recovering from or concealing the loss of the informationto be transmitted and may determine to include a null packet in the PDU with the RTP packet that carries information.

[0104] As shown at 240, the UPF 205 may receive the PDU that may be transmitted from the AS 213.

[0105] If the AS included a null packet in the PDU, the UPF may detect the presence of the null packet based on an indication in the RTP header.

[0106] The UPF may transmit the PDU to the RAN node 203 in a GTP-U message. The header of the GTP-U message may indicate that the PDU may contain (e.g., both) an RTP packet and an associated NULL packet. The header of the GTP-U message may (e.g., also) indicate the size of the RTP packet and / or null packet so that the RAN node 203 may know (e.g., may be indicated) which part of the PDU may be the null packet and which part of the PDU may not be the null packet.

[0107] As shown at 250, the RAN node 203 may receive the GTP-U message from the UPF 205.

[0108] The RAN node 203 may detect that the PDU in the GTP-U message may include (e.g., both) an RTP packet and an associated null packet.

[0109] Reception of the PDU may trigger the RAN node 203 to start a first discard timer with a first value and a second discard timer with a second value. The second value may be larger than the first value.

[0110] The first value may be based on the PSDB value that may have been received in the QoS profile.

[0111] The second value may be based on the NPSDB value that may have been received in the QoS profile.

[0112] If the RAN node 203 determines that information from the PDU can be transmitted to the WTRU 201 before the first timer expires, the RAN node may transmit the RTP packet as the PDU and may discard the null packet.

[0113] If the RAN node 203 determines that information from the PDU can be transmitted to the WTRU 201 after the first timer expires but before the second timer expires, the RAN node may transmit the null packet as the PDU and may discard the RTP packet. The RAN node may not be able to transmit the packet until after the first timer expires because of a congestion situation in the RAN node.

[0114] If the RAN node 203 determines that information from the PDU can not be transmittedto the WTRU 201 before the second timer expires, the RAN node may discard (e.g., both) the RTP packet and the null packet. The RAN node may not be able to transmit the packet before the second timer expires because of a relatively larger congestion situation in the RAN node.

[0115] As shown at 260, the RAN 203 may send the null packet or the RTP packet to the WTRU 201. Sending the null packet or the RTP packet to the WTRU 201 may be skipped if the second discard timer expired.

[0116] As shown at 270, the WTRU application may receive the RTP packet or the null packet from the RAN node. If the WTRU application receives a null packet, the WTRU application may use information from the header of the null packet to determine what information and how much information is missing. The error concealment and forward error correction algorithms of the WTRU application may continue processing and account for the missing data.RAN Node Provided Null Packets

[0117] In another example, the AS may not transmit null packets. The AS may include an indication in the RTP header of a packet. The indication may indicate that the network may be allowed to replace the packet with a null packet.

[0118] For example, the procedure of FIG. 2 may be modified so that, when the UPF receives a PDU from the AS, the UPF may forward the PDU to the RAN node in a GTP-U message. The UPF may indicate, in the GTP-U header, whether the RAN node is permitted to replace the PDU with a null packet.

[0119] The RAN node may determine to transmit a null packet to the WTRU as described in connection with FIG. 2. If the RAN node determines to transmit a null packet, the RAN node may use information from the GTP-U header to build the null packet. The RAN node may (e.g., only) determine to transmit the null packet if an indication in the GTP-U header indicates that the packet may be allowed to be replaced with a null packet. For example, the null packet may be a PDU that may be sent to the WTRU and may contain a NULL network abstraction layer (NAL) unit. The RTP header may indicate to the WTRU that a NULL NAL unit has replaced the actual NAL unit (e.g., the NAL unit that was transmitted by the AS).

[0120] In another example, the QoS profile may indicate to the RAN node that any packet in a QoS flow may be allowed to be replaced with a null packet.

[0121] In another example, the QoS profile may indicate limits to the RAN node about what packets in a QoS flow may be allowed to be replaced with a null packet. For example, the limits may indicate that (e.g., only) packets in a (e.g., certain) size range may be replaced. In anotherexample, the limits may indicate that (e.g., only) packets with (e.g., certain) information in the packet header (e.g., synchronization source (SSRC) value or sequence number range) may be replaced. In yet another example, the limits may indicate a limit on the rate of replacement. In a further example, the limits may indicate that (e.g., only) one out of (e.g., every) 150 packets may be replaced.

[0122] In an example, a method implemented in a network element of a communication network is disclosed. The method may comprise receiving a QoS profile indicating a delay budget and a notification delay budget. The method may further comprise receiving a message comprising a first data packet that is not a null packet and an indication that the node may be permitted to replace the first data packet with a null packet. The method may further comprise determining whether the network element begins transmitting content of the message to a WTRU before or after a first duration may have elapsed after the message may have been received, the first duration being based on the delay budget. The method may further comprise determining whether the network element begins transmitting the content of the message before or after a second duration may have elapsed after the message may have been received, the second duration being based on the notification delay budget. The method may further comprise generating a null packet and replacing the first data packet by the null packet for transmission to the WTRU (e.g., in replacement of the first data packet) based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed. The method may further comprise performing no transmission and discarding the first data packet based on the transmitting not having begun after the second duration having elapsed after the message may have been received.Example RTP Header Extension

[0123] In the example procedure of FIG. 2, the PDU that may be sent from the AS to the network may include: (a) a first RTP header indicating that the PDU may include a packet that may be followed by X bytes which may represent a null packet and the null packet’s header, (b) a packet (e.g., an RTP packet), (c) an RTP header for the null packet, and (d) a null packet (e.g., 0 bytes).

[0124] The RTP packet may include a header extension with a local identifier that may indicate that the RTP packet may be a null packet that may replace a packet that is not a null packet. The local identifier may be indicated in the ID field of a header. The header of the RTP packet may (e.g., also) include information about the packet that was dropped. The information aboutthe packet that was dropped may include any of the size of the packet that was dropped, the PDU set sequence number (PSSN) of the packet that was dropped, the PDU sequence number within a PDU set (PSN) of the packet that was dropped, and / or the PDU set size (PS Size) of the PDU set that the dropped packet may belong to. The information about the packet that was dropped may (e.g., also) include the SSRC of the packet and the sequence number of the packet.Example Methods for Early Notification of Dropped Packets

[0125] In an example, a method implemented in a node of a communication network for notifying a receiving node of a dropped packet is disclosed. The method may comprise receiving a QoS profile corresponding to a QoS flow. The method may further comprise receiving a message, the message comprising a first data packet that is not a null packet, a second data packet that is a null packet, and a header indicating that the message may include a non-null data packet and a null data packet. The method may further comprise starting a first timer associated with the message, the first timer having a first duration. The method may further comprise starting a second timer associated with the message, the second timer having a second duration longer than the first duration. In various embodiments, if the node begins transmitting the content of the message to a WTRU after the first timer expires and before the second timer expires, the node may transmit only the null packet to the WTRU and, if the node does not begin transmitting the content of the message to the WTRU before the second timer expires, the node may not transmit the content of the message to the WTRU.

[0126] In various embodiments, if the node begins transmitting the content of the message to the WTRU before the first timer expires, the node may transmit only the non-null packet to the WTRU.

[0127] In various embodiments, the message may be a GTP-U message.

[0128] In various embodiments, the first and second data packets may be RTP packets.

[0129] In various embodiments, the header may further comprise information disclosing which portion of the message may comprise the non-null packet and which portion of the message may comprise the null packet.

[0130] In various embodiments, the first timer duration may be based on a PDU set delay budget (PSDB) that may be part of the QoS profile, and the second timer duration may be based on a notification PSDB that may be part of the QoS profile.

[0131] In various embodiments, the header may comprise an indication that a null packet may be appended to the end of a PDU and an indication of the size of the null packet.

[0132] In various embodiments, the header may be the header of the first data packet.

[0133] In an example, another method implemented in a node of a communication network for notifying a receiving node of a dropped packet is disclosed. The method may comprise receiving a QoS profile corresponding to a QoS flow. The method may further comprise receiving a message, the message comprising a non-null data packet and an indication that the node may be permitted to replace the packet with a null packet. The method may further comprise starting a first timer associated with the message, the first timer having a first duration. The method may further comprise starting a second timer associated with the message, the second timer having a second duration longer than the first duration. In various embodiments, if the node does not begin transmitting the non-null data packet to a WTRU before the first timer expires but can transmit data to the WTRU before the second timer expires, the node may create and transmit a null data packet to the WTRU and may discard (e.g., not transmit) the non-null data packet. If the node does not begin transmitting data to the WTRU before the second timer expires, the node may discard (e.g., not transmit) the non-null data packet.

[0134] In various embodiments, the message may be a GTP-U message.

[0135] In various embodiments, the first and second data packets may be RTP packets.

[0136] In various embodiments, the first timer duration may be based on a PDU set delay budget (PSDB) that may be part of the QoS profile, and the second timer duration may be based on a notification PSDB that may be part of the QoS profile.

[0137] FIG. 3 is a diagram illustrating an example method 300 for early notifications of dropped packets. The method may be implemented in a network element of a communication network. As shown at 310, the method 300 may include receiving a QoS profile indicating a delay budget and a notification delay budget. As shown at 320, the method 300 may include receiving a message comprising a first data packet that may not be a null packet and a second data packet that may be a null packet. As shown at 330, the method 300 may include determining whether the network element begins transmitting content of the message to a WTRU before or after a first duration has elapsed after the message has been received, the first duration being based on the delay budget. As shown at 340, the method 300 may include determining whether the network element begins transmitting the content of the message before or after a second duration has elapsed after the message has been received, the second duration being based on the notification delay budget. As shown at 350, the method 300 may includetransmitting only the second data packet that may be the null packet to the WTRU based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed. As shown at 360, the method 300 may include discarding both the first data packet and the second data packet based on the transmitting not having begun after the second duration having elapsed.

[0138] In various embodiments, transmitting only the second data packet that may be the null packet to the WTRU may indicate that a data packet may have been dropped.

[0139] In various embodiments, the method may further comprise transmitting only the first data packet that may not be a null packet to the WTRU based on the transmitting beginning before the first duration having elapsed.

[0140] In various embodiments, the message may be a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message.

[0141] In various embodiments, the first data packet and the second data packet may be realtime transport protocol (RTP) packets.

[0142] In various embodiments, the message may comprise a first header indicating that the message may include a non-null packet and a null packet.

[0143] In various embodiments, the first header may further indicate which portion of the message may comprise the non-null packet and which portion of the message may comprise the null packet.

[0144] In various embodiments, the first header may further comprise an indication that a null packet may be appended to an end of a PDUand an indication of a size of the null packet.

[0145] In various embodiments, the first header may be a header of the first data packet.

[0146] In various embodiments, transmitting only the second data packet that may be a null packet may comprise transmitting the second data packet with a second header including information about the first data packet that may not have been transmitted.

[0147] In various embodiments, the information about the first data packet may indicate any of (1) a size of the first data packet, (2) a PDU set sequence number of the first data packet, (3) a PDU sequence number within a PDU set of the first data packet and (5) a size of the PDU set to which the first data packet may belong.

[0148] In various embodiments, the delay budget may be a PDU set delay budget (PSDB) that may be part of the QoS profile. In various embodiments, the notification delay budget may be a notification PSDB that may be part of the QoS profile

[0149] In various embodiments, the network element may comprise a radio access network (RAN) network element.

[0150] Embodiments have been described herein with a PSDB and NPSDB as examples of delay budgets. Embodiments are not limited to any of the PSDB and NPSDB and may be applicable to (i) any kind of delay budgets for the transmission of any set of packets and to (ii) any kind of notification delay budget for notifying the outcome of a transmission.

[0151] While not explicitly described, embodiments described herein may be employed in any combination or sub-combination. For example, the present principles are not limited to the described variants, and any arrangement of variants and embodiments can be used.

[0152] Besides, any characteristic, variant or embodiment described for a method is compatible with an apparatus device comprising means for processing the disclosed method, with a device comprising circuitry, including any of a transmitter, a receiver, a processor, a processor and a memory configured to process the disclosed method, with a computer program product comprising program code instructions and with a non-transitory computer-readable storage medium storing program instructions.

[0153] Although features and elements are provided above in particular combinations, one of ordinary skill in the art will appreciate that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not to be limited in terms of the particular embodiments described in this application, which are intended as illustrations of various aspects. Many modifications and variations may be made without departing from its spirit and scope, as will be apparent to those skilled in the art. No element, act, or instruction used in the description of the present application should be construed as critical or essential to the invention unless explicitly provided as such. Functionally equivalent methods and apparatuses within the scope of the disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing descriptions. Such modifications and variations are intended to fall within the scope of the appended claims. The present disclosure is to be limited only by the terms of the appended claims, along with the full scope of equivalents to which such claims are entitled. It is to be understood that this disclosure is not limited to particular methods or systems.

[0154] The foregoing embodiments are discussed, for simplicity, with regard to the terminology and structure of infrared capable devices, i.e., infrared emitters and receivers. However, the embodiments discussed are not limited to these systems but may be applied toother systems that use other forms of electromagnetic waves or non-electromagnetic waves such as acoustic waves.

[0155] It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting. As used herein, the term “video” or the term “imagery” may mean any of a snapshot, single image and / or multiple images displayed over a time basis. As another example, when referred to herein, the terms “user equipment” and its abbreviation “UE”, the term “remote” and / or the terms “head mounted display” or its abbreviation “HMD” may mean or include (i) a wireless transmit and / or receive unit (WTRU); (ii) any of a number of embodiments of a WTRU; (iii) a wireless- capable and / or wired-capable (e.g., tetherable) device configured with, inter alia, some or all structures and functionality of a WTRU; (iii) a wireless-capable and / or wired-capable device configured with less than all structures and functionality of a WTRU; or (iv) the like. Details of an example WTRU, which may be representative of any WTRU recited herein, are provided herein with respect to FIGs. 1A-1D. As another example, various disclosed embodiments herein supra and infra are described as utilizing a head mounted display. Those skilled in the art will recognize that a device other than the head mounted display may be utilized and some or all of the disclosure and various disclosed embodiments can be modified accordingly without undue experimentation. Examples of such other device may include a drone or other device configured to stream information for providing the adapted reality experience.

[0156] In addition, the methods provided herein may be implemented in a computer program, software, or firmware incorporated in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magnetooptical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). A processor in association with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, MME, AMF, or any host computer.

[0157] Variations of the method, apparatus and system provided above are possible without departing from the scope of the invention. In view of the wide variety of embodiments thatcan be applied, it should be understood that the illustrated embodiments are examples only, and should not be taken as limiting the scope of the following claims. For instance, the embodiments provided herein include handheld devices, which may include or be utilized with any appropriate voltage source, such as a battery and the like, providing any appropriate voltage.

[0158] Moreover, in the embodiments provided above, processing platforms, computing systems, controllers, and other devices that include processors are noted. These devices may include at least one Central Processing Unit (“CPU”) and memory. In accordance with the practices of persons skilled in the art of computer programming, reference to acts and symbolic representations of operations or instructions may be performed by the various CPUs and memories. Such acts and operations or instructions may be referred to as being “executed”, “computer executed” or “CPU executed”.

[0159] One of ordinary skill in the art will appreciate that the acts and symbolically represented operations or instructions include the manipulation of electrical signals by the CPU. An electrical system represents data bits that can cause a resulting transformation or reduction of the electrical signals and the maintenance of data bits at memory locations in a memory system to thereby reconfigure or otherwise alter the CPU’s operation, as well as other processing of signals. The memory locations where data bits are maintained are physical locations that have particular electrical, magnetic, optical, or organic properties corresponding to or representative of the data bits. It should be understood that the embodiments are not limited to the above- mentioned platforms or CPUs and that other platforms and CPUs may support the provided methods.

[0160] The data bits may also be maintained on a computer readable medium including magnetic disks, optical disks, and any other volatile (e.g., Random Access Memory (RAM)) or non-volatile (e.g., Read-Only Memory (ROM)) mass storage system readable by the CPU. The computer readable medium may include cooperating or interconnected computer readable medium, which exist exclusively on the processing system or are distributed among multiple interconnected processing systems that may be local or remote to the processing system. It should be understood that the embodiments are not limited to the above-mentioned memories and that other platforms and memories may support the provided methods.

[0161] In an illustrative embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readablemedium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0162] There is little distinction left between hardware and software implementations of aspects of systems. The use of hardware or software is generally (but not always, in that in certain contexts the choice between hardware and software may become significant) a design choice representing cost versus efficiency tradeoffs. There may be various vehicles by which processes and / or systems and / or other technologies described herein may be effected (e.g., hardware, software, and / or firmware), and the preferred vehicle may vary with the context in which the processes and / or systems and / or other technologies are deployed. For example, if an implementer determines that speed and accuracy are paramount, the implementer may opt for a mainly hardware and / or firmware vehicle. If flexibility is paramount, the implementer may opt for a mainly software implementation. Alternatively, the implementer may opt for some combination of hardware, software, and / or firmware.

[0163] The foregoing detailed description has set forth various embodiments of the devices and / or processes via the use of block diagrams, flowcharts, and / or examples. Insofar as such block diagrams, flowcharts, and / or examples include one or more functions and / or operations, it will be understood by those within the art that each function and / or operation within such block diagrams, flowcharts, or examples may be implemented, individually and / or collectively, by a wide range of hardware, software, firmware, or virtually any combination thereof. In an embodiment, several portions of the subject matter described herein may be implemented via Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), digital signal processors (DSPs), and / or other integrated formats. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein, in whole or in part, may be equivalently implemented in integrated circuits, as one or more computer programs running on one or more computers (e.g., as one or more programs running on one or more computer systems), as one or more programs running on one or more processors (e.g., as one or more programs running on one or more microprocessors), as firmware, or as virtually any combination thereof, and that designing the circuitry and / or writing the code for the software and or firmware would be well within the skill of one of skill in the art in light of this disclosure. In addition, those skilled in the art will appreciate that the mechanisms of the subj ect matter described herein may be distributed as a program product in a variety of forms, and that an illustrative embodiment of the subject matter described herein applies regardless of theparticular type of signal bearing medium used to actually carry out the distribution. Examples of a signal bearing medium include, but are not limited to, the following: a recordable type medium such as a floppy disk, a hard disk drive, a CD, a DVD, a digital tape, a computer memory, etc., and a transmission type medium such as a digital and / or an analog communication medium (e.g., a fiber optic cable, a waveguide, a wired communications link, a wireless communication link, etc.).

[0164] Those skilled in the art will recognize that it is common within the art to describe devices and / or processes in the fashion set forth herein, and thereafter use engineering practices to integrate such described devices and / or processes into data processing systems. That is, at least a portion of the devices and / or processes described herein may be integrated into a data processing system via a reasonable amount of experimentation. Those having skill in the art will recognize that a typical data processing system may generally include one or more of a system unit housing, a video display device, a memory such as volatile and non-volatile memory, processors such as microprocessors and digital signal processors, computational entities such as operating systems, drivers, graphical user interfaces, and applications programs, one or more interaction devices, such as a touch pad or screen, and / or control systems including feedback loops and control motors (e.g., feedback for sensing position and / or velocity, control motors for moving and / or adjusting components and / or quantities). A typical data processing system may be implemented utilizing any suitable commercially available components, such as those typically found in data computing / communication and / or network computing / communication systems.

[0165] The herein described subject matter sometimes illustrates different components included within, or connected with, different other components. It is to be understood that such depicted architectures are merely examples, and that in fact many other architectures may be implemented which achieve the same functionality. In a conceptual sense, any arrangement of components to achieve the same functionality is effectively “associated” such that the desired functionality may be achieved. Hence, any two components herein combined to achieve a particular functionality may be seen as “associated with” each other such that the desired functionality is achieved, irrespective of architectures or intermedial components. Likewise, any two components so associated may also be viewed as being “operably connected”, or “operably coupled”, to each other to achieve the desired functionality, and any two components capable of being so associated may also be viewed as being “operably couplable” to each otherto achieve the desired functionality. Specific examples of operably couplable include but are not limited to physically mateable and / or physically interacting components and / or wirelessly interactable and / or wirelessly interacting components and / or logically interacting and / or logically interactable components.

[0166] With respect to the use of substantially any plural and / or singular terms herein, those having skill in the art can translate from the plural to the singular and / or from the singular to the plural as is appropriate to the context and / or application. The various singular / plural permutations may be expressly set forth herein for sake of clarity.

[0167] It will be understood by those within the art that, in general, terms used herein, and especially in the appended claims (e.g., bodies of the appended claims) are generally intended as “open” terms (e.g., the term “including” should be interpreted as “including but not limited to,” the term “having” should be interpreted as “having at least,” the term “includes” should be interpreted as “includes but is not limited to,” etc.) and / or “permissive” terms (e.g., the term “is” and / or the term “are” may be interpreted as “may” and / or “might”, the terms ”"refer(s)" may be interpreted as "may refer" and / or "might refer", the terms "receive(s)" may be interpreted as "may receive" and / or "might receive", the terms "support(s)" may be interpreted as "may support" and / or "might support", the terms "interface(s)" may be interpreted as "may interface" and / or "might interface", the terms "transmit(s)" may be interpreted as "may interface" and / or "might interface", "may transmit" and / or "might transmit", the terms "send(s)" may be interpreted as "may send" and / or "might send", the terms "does not refer" (and / or the like) may be interpreted as "may not refer" and / or "might not refer", the terms "does not receive" (and / or the like) may be interpreted as "may not receive" and / or "might not receive", the terms "does not support" (and / or the like) may be interpreted as "may not support" and / or "might not support", the terms "does not interface" (and / or the like) may be interpreted as "may not interface" and / or "might not interface", the terms "does not transmit" (and / or the like) may be interpreted as "may not transmit" and / or "might not transmit", the terms "does not send" (and / or the like) may be interpreted as "may not send" and / or "might not send", etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, where only one item is intended, the term "single" or similar language may be used. As an aid to understanding, the following appended claims and / or the descriptions herein may include usage of theintroductory phrases "at least one" and "one or more" to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles "a" or "an" limits any particular claim including such introduced claim recitation to embodiments including only one such recitation, even when the same claim includes the introductory phrases "one or more" or "at least one" and indefinite articles such as "a" or "an" (e.g., "a" and / or "an" should be interpreted to mean "at least one" or "one or more"). The same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should be interpreted to mean at least the recited number (e.g., the bare recitation of "two recitations," without other modifiers, means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to "at least one of A, B, and C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In those instances where a convention analogous to "at least one of A, B, or C, etc." is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and / or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase "A or B" will be understood to include the possibilities of "A" or "B" or "A and B." Further, the terms "any of followed by a listing of a plurality of items and / or a plurality of categories of items, as used herein, are intended to include "any of," "any combination of," "any multiple of," and / or "any combination of multiples of the items and / or the categories of items, individually or in conjunction with other items and / or other categories of items. Moreover, as used herein, the term "set" is intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero. And the term "multiple", as used herein, is intended to be synonymous with "a plurality".

[0168] In addition, where features or aspects of the disclosure are described in terms of Markush groups, those skilled in the art will recognize that the disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0169] As will be understood by one skilled in the art, for any and all purposes, such as in terms of providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of subranges thereof. Any listed range can be easily recognized as sufficiently describing and enabling the same range being broken down into at least equal halves, thirds, quarters, fifths, tenths, etc. As a non-limiting example, each range discussed herein may be readily broken down into a lower third, middle third and upper third, etc. As will also be understood by one skilled in the art all language such as "up to," "at least," "greater than," "less than," and the like includes the number recited and refers to ranges which can be subsequently broken down into subranges as discussed above. Finally, as will be understood by one skilled in the art, a range includes each individual member. Thus, for example, a group having 1-3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1-5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so forth.

[0170] Moreover, the claims should not be read as limited to the provided order or elements unless stated to that effect. In addition, use of the terms "means for" in any claim is intended to invoke 35 U.S.C. §112, 6 or means-plus-function claim format, and any claim without the terms "means for" is not so intended.

[0171] Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Application Specific Standard Products (ASSPs); Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and / or a state machine.

[0172] The WTRU may be used in conjunction with modules, implemented in hardware and / or software including a Software Defined Radio (SDR), and other components such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a Near Field Communication (NFC) Module, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, adigital music player, a media player, a video game player module, an Internet browser, and / or any Wireless Local Area Network (WLAN) or Ultra Wide Band (UWB) module.

[0173] Although the various embodiments have been described in terms of communication systems, it is contemplated that the systems may be implemented in software on microprocessors / general purpose computers (not shown). In certain embodiments, one or more of the functions of the various components may be implemented in software that controls a general-purpose computer.

[0174] In addition, although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

[0175] The content of each of the following references is incorporated by reference herein in its entirety:[1] TS 23.501, System architecture for the 5G System (5GS); Stage 2 V18.3.0[2] TS 23.502, Procedures for the 5G System (5GS); Stage 2 VI 8.3.0[3] TS 23.503, Policy and charging control framework for the 5G System (5GS); Stage 2 V18.3.0[4] TS 26.522, 5G Real-time Media Transport Protocol Configurations V0.1.1[5] RFC 8285, General Mechanism for RTP Header Extension

Claims

CLAIMS1. A method implemented in a network element, the method comprising: receiving a quality of service (QoS) profile indicating a delay budget and a notification delay budget; receiving a message comprising a first data packet that is not a null packet and a second data packet that is a null packet; determining whether the network element begins transmitting content of the message to a wireless transmit / receive unit (WTRU) before or after a first duration has elapsed after the message has been received, wherein the first duration is based on the delay budget; determining whether the network element begins transmitting the content of the message before or after a second duration has elapsed after the message has been received, wherein the second duration is based on the notification delay budget; transmitting only the second data packet that is the null packet to the WTRU based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed; and discarding both the first data packet and the second data packet based on the transmitting not having begun after the second duration having elapsed.

2. The method of claim 1, wherein transmitting only the second data packet that is the null packet to the WTRU indicates that a data packet has been dropped.

3. The method of any of claims 1 to 2, further comprising transmitting only the first data packet that is not a null packet to the WTRU based on the transmitting beginning before the first duration having elapsed.

4. The method of any of claims 1 to 3, wherein the message is a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message.

5. The method of any of claims 1 to 4, wherein the first data packet and the second data packet are real-time transport protocol (RTP) packets.

6. The method of any of claims 1 to 5, wherein the message comprises a first header indicating that the message includes a non-null packet and a null packet.

7. The method of claim 6, wherein the first header further indicates which portion of the message comprises the non-null packet and which portion of the message comprises the null packet.

8. The method of any of claims 6 to 7, wherein the first header further comprises an indication that a null packet is appended to an end of a protocol data unit (PDU) and an indication of a size of the null packet.

9. The method of any of claims 6 to 8, wherein the first header is a header of the first data packet.

10. The method of any of claims 1 to 9, wherein transmitting only the second data packet that is a null packet comprises transmitting the second data packet with a second header including information about the first data packet that was not transmitted.

11. The method of claim 10, wherein the information about the first data packet indicates any of (1) a size of the first data packet, (2) a PDU set sequence number of the first data packet, (3) a PDU sequence number within a PDU set of the first data packet and (5) a size of the PDU set to which the first data packet belongs.

12. The method of any of claims 1 to 11, wherein the delay budget is a PDU set delay budget (PSDB) that is part of the QoS profile and wherein the notification delay budget is a notification PSDB that is part of the QoS profile.

13. The method of any of claims 1 to 12, wherein the network element comprises a radio access network (RAN) network element.

14. A network element comprising circuitry, including any of a transmitter, a receiver, a processor, and a memory, wherein the network element is configured to:receive a quality of service (QoS) profile indicating a delay budget and a notification delay budget; receive a message comprising a first data packet that is not a null packet and a second data packet that is a null packet; determine whether the network element begins transmitting content of the message to a wireless transmit / receive unit (WTRU) before or after a first duration has elapsed after the message has been received, wherein the first duration is based on the delay budget; determine whether the network element begins transmitting the content of the message before or after a second duration has elapsed after the message has been received, wherein the second duration is based on the notification delay budget; transmit only the second data packet that is the null packet to the WTRU based on the transmitting beginning after the first duration having elapsed and before the second duration having elapsed; and discard both the first data packet and the second data packet based on the transmitting not having begun after the second duration having elapsed.

15. The network element of claim 14, wherein transmit only the second data packet that is the null packet to the WTRU indicates that a data packet has been dropped.

16. The network element of any of claims 14 to 15, wherein the network element is further configured to transmit only the first data packet that is not a null packet to the WTRU based on transmitting beginning before the first duration having elapsed.

17. The network element of any of claims 14 to 16, wherein the message is a general packet radio service (GPRS) tunneling protocol-user plane (GTP-U) message.

18. The network element of any of claims 14 to 17, wherein the first data packet and the second data packet are real-time transport protocol (RTP) packets.

19. The network element of any of claims 14 to 18, wherein the message comprises a first header indicating that the message includes a non-null packet and a null packet.

20. The network element of claim 19, wherein the first header further indicates which portion of the message comprises the non-null packet and which portion of the message comprises the null packet.

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