Method, device, and system for supporting mobile-initiated connectivity-only (MICO) wireless transmit / receive unit (WTRU)

Abstract

To provide a method, a device, and a system for supporting mobile-initiated connectivity-only (MICO) wireless transmit / receive unit (WTRU).SOLUTION: A method, a device, and a system for managing the connection state of a WTRU in a MICO mode are disclosed. The method may include obtaining information indicating that the WTRU is to initiate registration before sending a Service Request (SR) by the WTRU. The method may further include sending a registration request according to the obtained information and sending an SR after registration with the network entity by the WTRU.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present disclosure relates to the field of wireless communications, and more particularly to methods, apparatus, and systems supporting Mobile Initiated Connection Only (MICO) WTRUs (e.g., in 5G). [Background technology]

[0002] This application claims priority from U.S. Provisional Patent Application No. 62 / 502,043, filed May 5, 2017, the contents of which are incorporated by reference as if fully set forth herein. Summary of the Invention [Means for solving the problem]

[0003] A method, apparatus, and system are disclosed for managing a connection state of a wireless transmit / receive unit (WTRU) in a mobile-initiated communication-only (MICO) mode. One exemplary method may include the WTRU obtaining information indicating that the WTRU will initiate registration before sending a service request (SR). The exemplary method may further include the WTRU sending a registration request according to the obtained information and sending the SR after registering with a network entity.

[0004] A more detailed understanding can be had from the following detailed description, which is given by way of example in conjunction with the drawings attached hereto. The figures in such drawings, like the detailed description, are examples. Therefore, the drawings and detailed description should not be considered limiting, as other equally effective examples are possible and likely to exist. Moreover, like reference numerals refer to like elements throughout the figures. [Effects of the Invention]

[0005] A method, apparatus, and system for supporting a mobile initiated connection only (MICO) wireless transmit / receive unit (WTRU) are provided. [Brief explanation of the drawings]

[0006] [Figure 1A] FIG. 1 illustrates an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1B illustrates an exemplary wireless transmit / receive unit (WTRU) for use within the communications system of FIG. 1A in an embodiment. [Figure 1C] 1B is a diagram of an exemplary radio access network (RAN), core network (CN) used in the communication system of FIG. 1A in an embodiment. [Figure 1D] 1B illustrates another exemplary RAN and another CN used in the communication system of FIG. 1A in an embodiment. [Figure 1E] 1B illustrates another exemplary radio access network and another CN that may be used within the communication system of FIG. 1A. [Figure 1F] 1B illustrates yet another exemplary access network and yet another CN that may be used within the communication system of FIG. 1A. [Figure 2] FIG. 10 is a diagram of a representative MICOWTRU moving to a new serving AMF. [Figure 3] This is a state diagram including the RRC_INACTIVE state, which is typical for 5G new radio. [Figure 4] FIG. 1 illustrates a typical registration procedure. [Figure 5] FIG. 1 illustrates a typical decision procedure. [Figure 6] FIG. 10 illustrates another exemplary decision procedure. [Figure 7] 1 is a diagram of an exemplary service request (SR) triggered WTRU context acquisition procedure. [Figure 8] FIG. 1 illustrates a registration / SR procedure. [Figure 9] FIG. 1 illustrates a representative MICO WTRU initiated disconnection procedure. [Figure 10] 1 is a diagram of an exemplary procedure for the RAN to recognize the MICO mode of the WTRU. [Figure 11] FIG. 10 is a diagram of a RAN signaling acceptance / rejection procedure for a MICO WTRU. [Figure 12] FIG. 1 is a flow diagram illustrating an exemplary method for facilitating SR. [Figure 13] FIG. 1 is a flow diagram illustrating another exemplary method for facilitating SR. [Figure 14] FIG. 1 is a flow diagram illustrating another exemplary method for facilitating SR. [Figure 15] FIG. 1 is a flow diagram illustrating a further exemplary method for facilitating SR. [Figure 16] FIG. 10 is a flow diagram illustrating yet another exemplary method for facilitating SR. [Figure 17] FIG. 10 is a flow diagram illustrating yet another exemplary method for facilitating SR. [Figure 18] FIG. 10 is a flow diagram of yet another method for accepting or rejecting a disconnection. [Figure 19] FIG. 1 is a flow diagram illustrating an exemplary method for facilitating registration. [Figure 20] FIG. 1 is a flow diagram of an exemplary method implemented in a NW to facilitate SR. [Figure 21] FIG. 10 is another method flow diagram in which a WTRU is implemented in a NW in MICO mode. [Figure 22] FIG. 10 is a flow diagram of another NW-implemented method for facilitating a connection request. [Figure 23] FIG. 10 is a flow diagram of a further exemplary method implemented in a NW that facilitates SR. [Figure 24] FIG. 1 is a flow diagram illustrating an exemplary method implemented in a NW for facilitating registration. [Figure 25] FIG. 1 is a flow diagram of an exemplary method implemented in a RAN entity for facilitating SR. DETAILED DESCRIPTION OF THE INVENTION

[0007] A detailed description of exemplary embodiments will now be provided with reference to the figures. However, it should be understood that while the invention may be described with reference to exemplary embodiments, it is not limited thereto, and that other embodiments may be used, or modifications or additions may be made to the described embodiments, to perform the same functions of the invention without departing from the invention.

[0008] Although exemplary embodiments are generally illustrated below using a wireless network architecture, any number of different network architectures may be used, including, for example, networks having wired and / or wireless components.

[0009] 1A illustrates an exemplary communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system providing content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communication system 100 enables the multiple wireless users to access such content by sharing system resources, including wireless bandwidth. For example, the communication system 100 may use 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-tailed 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.

[0010] 1A, communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, and 102d, radio access networks (RANs) 103 / 104 / 105 / 113, CNs 106 / 107 / 109 / 115, public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of WTRUs 102a, 102b, 102c, and 102d may be any type of device configured to operate and / or communicate in a wireless environment. By way of example, the WTRUs 102a, 102b, 102c, 102d, any of which may be referred to as a “station” and / or “STA,” are configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, personal digital assistants (PDAs), smartphones, laptops, netbooks, personal computers, wireless sensors, hotspot or Mi-Fi devices, Internet of Things (IoT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain situations), consumer electronic devices, devices operating in commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be referred to interchangeably as UEs.

[0011] The communications system 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 communications networks, such as the CNs 106 / 107 / 109 / 115, the Internet 110, and / or other networks 112. By way of example, the base stations 114a, 114b may be a Base Transceiver Station (BTS), a Node B, an eNodeB, a 5G access point (e.g., gNB), a Home Node B, a Home eNodeB, an NR Node B, a site controller, an Access Point (AP), a wireless router, and the like. While the base stations 114a, 114b are each shown as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0012] The base station 114a may be part of the RAN 103 / 104 / 105 / 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 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). The cells may be further divided into cell sectors. These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for wireless service to a particular geographic area, which may be relatively fixed over time or may change. The cells may be further 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, e.g., one for each sector of the cell. In an embodiment, the base station 114a may use multiple-input multiple-output (MIMO) technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0013] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d via air interfaces 115 / 116 / 117 / 119, 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 interfaces 115 / 116 / 117 / 119 may be established using any suitable radio access technology (RAT).

[0014] More specifically, as noted above, the communication system 100 may be a multiple access system and may use 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 RANs 103 / 104 / 105 / 113 and the WTRUs 102a, 102b, and 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interfaces 115 / 116 / 117 / 119 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 (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0015] In another 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 interfaces 115 / 116 / 117 / 119 using Long Term Evolution (LTE), and / or LTE Advanced (LTE-A), LTE Advanced Pro (LTE-A Pro), and / or 5G New Radio (NR).

[0016] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as NR radio access that may establish an air interface 119 using NR.

[0017] 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 both LTE radio access and NR radio access, e.g., using a dual connectivity (DC) principle. Thus, the radio interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to and from multiple types of base stations (e.g., eNBs and gNBs).

[0018] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as IEEE 802.11 (i.e., Wireless Fidelity (WiFi)), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), Global System for Mobile Communications (GSM), GSM Evolution Enhanced Data Rates (EDGE), GSM EDGE (GERAN), and the like.

[0019] 1A may be, for example, a wireless router, a Home NodeB, a Home eNodeB, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as a workplace, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., used by drones), a roadway, and similar locations. 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 another 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 cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. 1A, the base station 114b may have a direct connection to the Internet 110. Therefore, the base station 114b may not need to access the Internet 110 via the CNs 106 / 107 / 109 / 115.

[0020] The RANs 103 / 104 / 105 / 113 may communicate with the CNs 106 / 107 / 109 / 115, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as different throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, and the like. For example, the CNs 106 / 107 / 109 / 115 may provide call control, billing services, mobile location-based services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high-level security functions such as user authentication. 1A , it will be understood that the RANs 103 / 104 / 105 / 113 and / or the CNs 106 / 107 / 109 / 115 can communicate directly or indirectly with other RANs that use the same RAT as the RANs 103 / 104 / 105 / 113, or a different RAT. For example, in addition to being connected to the RANs 103 / 104 / 105 / 113, which may utilize NR or E-UTRA radio technology, the CNs 106 / 107 / 109 / 115 can also communicate with another RAN (not shown) that uses GSM, UMTS, CDMA2000, WiMAX, or WiFi radio technology.

[0021] The CNs 106 / 107 / 109 / 115 may also serve as gateways for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing 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 Transmission Control Protocol (TCP), User Datagram Protocol (UDP), and / or Internet Protocol (IP) in the TCP / IP Internet protocol suite. The network 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the network 112 may include another CN connected to one or more RANs, which may use the same RAT as the RANs 103 / 104 / 105 / 113 or a different RAT.

[0022] 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 a base station 114a that may use cellular-based wireless technology and with a base station 114b that may use IEEE 802 wireless technology. Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may communicate with other devices using, for example, Bluetooth technology.

[0023] 1B is a system diagram illustrating an example WTRU 102. As shown in FIG. 1B, the WTRU 102 may include, among other things, 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, an interference management unit 139, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the foregoing elements while remaining consistent with an embodiment.

[0024] The processor 118 may be a general-purpose processor, a special-purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DCP core, a controller, a microcontroller, an application-specific integrated circuit (ASIC), field programmable gate array (FPGA) circuitry, 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. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0025] The transmit / receive element 122 may be configured to transmit signals to and / or receive signals from a base station (e.g., base station 114a) via the air interface 115 / 116 / 117 / 119. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In another 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 understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0026] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may use 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 / or receiving wireless signals over the air interfaces 115 / 116 / 117 / 119.

[0027] The transceiver 120 may be configured to modulate signals transmitted by the transmit / receive element 122 and / or demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate over multiple RATs, such as, for example, NR, UTRA, and / or IEEE 802.11.

[0028] The processor 118 of the WTRU 102 may be coupled to, and may receive user input data from, a speaker / microphone 124, a keypad 126, and / or a display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an 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. Additionally, the processor 118 may access information from and / or store data in any type of suitable memory, such as non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include random access memory (RAM), read-only memory (ROM), a hard disk, or any 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 / or store data in memory that is not physically located on the WTRU 102, such as on a server or home computer (not shown).

[0029] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for providing power to the WTRU 102. For example, the power source 134 may include one or more dry 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.

[0030] The processor 118 may be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and / or latitude) regarding the current location of the WTRU 102. In addition to, or instead of, information from the GPS chipset 136, the WTRU 102 may receive location information from base stations (e.g., base stations 114a, 114b) over the air interface 115 / 116 / 117 / 119 and / or determine its location based on the timing of signals received from two or more nearby base stations. It will be appreciated that the WTRU 102 may obtain location information by way of any suitable location-determination method while remaining consistent with an embodiment.

[0031] The processor 118 may 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 electronic compass, a satellite transceiver, a digital camera (for photos and / or videos), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulation (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, which may be one or more of a gyroscope, an accelerometer, a Hall-effect sensor, a magnetometer, a direction sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor, etc.

[0032] The processor 118 of the WTRU 102 may be in operative communication with various peripherals 138, including, for example, one or more accelerometers, one or more gyroscopes, a USB port, other communication interfaces / ports, a display, and / or any other visual / audio indicators, to implement the representative embodiments disclosed herein.

[0033] The WTRU 102 may include a full-duplex radio, in which case transmission and reception of some or all of the signals associated with a particular subframe (e.g., for both the UL (e.g., for transmission) and downlink (e.g., for reception)) may be partially or fully coincident and / or simultaneous, for example. The full-duplex radio may include an interference management unit 139 to reduce and / or substantially eliminate self-interference by hardware (e.g., a choke) or signal processing by a processor (e.g., by a separate processor (not shown) or processor 118). In an embodiment, the WTRU 102 may include a half-duplex radio for transmitting and receiving some or all of the signals (e.g., associated with a particular subframe for the UL (e.g., for transmission) or downlink (e.g., for reception)).

[0034] 1C is a system diagram illustrating the RAN 103 and the CN 106 according to another embodiment. As described above, the RAN 103 may use UTRA radio technology to communicate with the WTRUs 102a, 102b, and 102c over the air interface 115. The RAN 103 may also communicate with the CN 106. As shown in FIG. 1C, the RAN 103 may include Node Bs 140a, 140b, and 140c, each of which may include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 115. Each of the Node Bs 140a, 140b, and 140c may be associated with a particular cell (not shown) within the RAN 103. The RAN 103 may also include RNCs 142a and 142b. It will be understood that the RAN 103 may include any number of Node Bs and RNCs while remaining consistent with the embodiment.

[0035] As shown in FIG. 1C , Node Bs 140a, 140b can communicate with RNC 142a. Additionally, Node B 140c can communicate with RNC 142b. Node Bs 140a, 140b, and 140c can communicate with each RNC 142a, 142b via an Iub interface. RNCs 142a, 142b can communicate with each other via an Iur interface. Each RNC 142a, 142b can be configured to control each Node B 140a, 140b, and 140c to which it is connected. Additionally, each RNC 142a, 142b can be configured to perform or support other functions, such as outer loop power control, load control, admission control, packet scheduling, handover control, macro diversity, security functions, data encryption, and the like.

[0036] 1C may include a media gateway (MGW) 144, a mobile switching center (MSC) 146, a serving GPRS support node (SGSN) 148, and / or a gateway GPRS support node (GGSN) 150. Although each of the foregoing elements is shown as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0037] The RNC 142a in the RAN 103 may be connected to the MSC 146 in the CN 106 via an IuCS interface. The MSC 146 may be connected to the MGW 144. The MSC 146 and MGW 144 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.

[0038] The RNC 142a in the RAN 103 may also be connected to an SGSN 148 in the CN 106 via an IuPS interface. The SGSN 148 may be connected to a GGSN 150. The SGSN 148 and GGSN 150 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.

[0039] As noted above, the CN 106 may also connect to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0040] 1D is a system diagram illustrating the RAN 104 and the CN 107 according to an embodiment. As mentioned above, the RAN 104 uses E-UTRA radio technology and can communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 can also communicate with the CN 107.

[0041] The RAN 104 may include eNodeBs 160a, 160b, and 160c, although it will be understood that the RAN 104 may include any number of eNodeBs while remaining consistent with an embodiment. The eNodeBs 160a, 160b, and 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 116. In one embodiment, the eNodeBs 160a, 160b, and 160c may implement MIMO techniques. Thus, for example, the eNodeB 160a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0042] Each of the eNodeBs 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 UL and / or DL, and the like. As shown in FIG. 1D, the eNodeBs 160a, 160b, 160c may communicate with each other via an X2 interface. The eNodeBs may include a full-duplex radio similar to that of the WTRU 102 (e.g., equipped with an interference management unit). The CN 107 shown in FIG. 1D may include a mobility management unit (MME) 162, a serving gateway (SGW) 164, and a packet data network (PDN) gateway (or PGW) 166. While each of the foregoing elements is shown as part of the CN 107, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0043] The MME 162 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 162 may handle authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during 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 use other radio technologies such as GSM and / or WCDMA.

[0044] The serving gateway 164 may be connected to each of the eNodeBs 160a, 160b, 160c in the RAN 104 via an S1 interface. The serving gateway 164 may generally route and forward user data packets to and from the WTRUs 102a, 102b, 102c. The serving gateway 164 may perform other functions such as fixing the user plane during handover between eNodeBs, triggering paging when DL data is available to the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, and the like.

[0045] The serving gateway 164 may be connected to a PDN gateway 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.

[0046] The CN 107 may facilitate communications with other networks. For example, the CN 107 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 107 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 107 and the PSTN 108. Additionally, the CN 107 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0047] 1E is a system diagram illustrating the RAN 105 and the CN 109 according to an embodiment. The RAN 105 may be an access service network (ASN) that uses IEEE 802.16 wireless technology to communicate with the WTRUs 102a, 102b, 102c over an air interface 117. As discussed further below, the communication links between various functional entities of the WTRUs 102a, 102b, 102c, the RAN 105, and the CN 109 may be defined as reference points.

[0048] 1E, the RAN 105 may include base stations 170a, 170b, and 170c and an ASN gateway 182, although it will be understood that the RAN 105 may include any number of base stations and ASN gateways while remaining consistent with an embodiment. The base stations 170a, 170b, and 170c may each be associated with a particular cell (not shown) in the RAN 105 and may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 117. In one embodiment, the base stations 170a, 170b, and 170c may implement MIMO technology. The base station 170a, for example, may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a. The base stations 170a, 170b, 170c may also provide mobility management functions such as handoff triggering, tunnel establishment, radio resource management, traffic classification, quality of service (QoS) policy enforcement, and the like. The ASN gateway 182 may act as a traffic aggregation point and may also handle paging, subscriber profile caching, routing to the CN 109, and the like.

[0049] The air interface 117 between the WTRUs 102a, 102b, 102c and the RAN 105 may be defined as an R1 reference point that implements the IEEE 802.16 standard. Additionally, each of the WTRUs 102a, 102b, 102c may establish a logical interface (not shown) with the CN 109. The logical interface between the WTRUs 102a, 102b, 102c and the CN 109 may be defined as an R2 reference point, which may be used for authentication, authorization, IP host configuration management, and / or mobility management.

[0050] The communication link between each of the base stations 170a, 170b, 170c may be defined as an R8 reference point that includes protocols for facilitating handover of WTRUs and the transfer of data between the base stations. The communication link between the base stations 170a, 170b, 170c and the ASN gateway 182 may be defined as an R6 reference point that may include protocols for facilitating mobility management based on mobility events associated with each of the WTRUs 102a, 102b, 102c.

[0051] 1E, the RAN 105 may be connected to the CN 109. The communication link between the RAN 105 and the CN 109 may be defined as an R3 reference point, which may include, for example, protocols for facilitating data transfer and mobility management functions. The CN 109 may include a Mobile IP Home Agent (MIP-HA) 184, an Authentication, Authorization, and Accounting (AAA) server 186, and a gateway 188. While each of the foregoing elements is shown as part of the CN 109, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0052] The MIP-HA 184 may handle IP address management and enable the WTRUs 102a, 102b, 102c to roam between different ASNs and / or different CNs. The MIP-HA 184 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 AAA server 186 may handle user authentication and support for user services. The gateway 188 may facilitate interconnection with other networks. For example, the gateway 188 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 landline communications devices. The gateway 188 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0053] 1E, it will be understood that the RAN 105 may be connected to other ASNs, other RANs (e.g., RANs 103 and / or 104), and / or the CN 109 may be connected to other CNs (e.g., CNs 106 and / or 107). The communication link between the RAN 105 and the other ASNs may be defined as an R4 reference point, which may include protocols for coordinating mobility of the WTRUs 102a, 102b, 102c between the RAN 105 and the other ASNs. The communication link between the CN 109 and the other CNs may be defined as an R5 reference point, which may include protocols for facilitating interoperation between a home CN and a visited CN.

[0054] In an exemplary embodiment, the other network 112 may be a WLAN.

[0055] 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 access to or interface with a distribution system (DS) or another type of wired / wireless network that carries traffic to and / or from the BSS. Traffic to a STA originating from outside the BSS may arrive through the AP and be delivered to the STA. Traffic originating from a STA to a destination outside the BSS may be sent to the AP and delivered to the destination. Traffic between STAs within a BSS may be sent, for example, through the AP, where the source STA may send traffic to the AP and the AP may deliver the traffic to the destination STA. Traffic between STAs within a BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs using direct link setup (DLS). In some representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may have no APs, and the STAs within or using the IBSS (e.g., all of the STAs) may communicate directly with each other. The IBSS mode of communication is sometimes referred to herein as an "ad hoc" mode of communication.

[0056] When using the 802.11ac infrastructure mode of operation, or a similar mode of operation, an AP can transmit beacons on a fixed channel, such as a primary channel. The primary channel can be a fixed width (e.g., a 20 MHz wide bandwidth) or a width that is dynamically set via signaling. The primary channel can be the operating channel of the BSS and can be used by STAs to establish a connection with the AP. In some representative embodiments, for example, in an 802.11 system, carrier sense multiple access with collision avoidance (CSMA / CA) can be implemented. With CSMA / CA, STAs (e.g., every STA), including the AP, can sense the primary channel. If a particular STA senses / detects and / or determines that the primary channel is busy, the particular STA may back off. One STA (e.g., only one station) can transmit at any given time in a given BSS.

[0057] A high-throughput (HT) STA may use a 40 MHz wide channel for communication, for example, by combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form the 40 MHz wide channel.

[0058] A very high throughput (VHT) STA can support 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz wide channels. 40 MHz and / or 80 MHz channels can be formed by combining adjacent 20 MHz channels. A 160 MHz channel can be formed by combining eight adjacent 20 MHz channels or two non-adjacent 80 MHz channels, which can be called an 80+80 configuration. For the 80+80 configuration, after channel encoding, the data can be passed through a segment parser that can split it into two streams. Inverse fast Fourier transform (IFFT) processing and time-domain processing can be performed separately for each stream. The streams can be mapped to two 80 MHz channels, and the data can be transmitted by the transmitting STA. At the receiver of the receiving STA, the operations described above for the 80+80 configuration can be reversed, and the combined data can be sent to the media access control (MAC).

[0059] Sub-1 GHz operating modes are supported by 802.11af and 802.11ah. The channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac, with 802.11af supporting 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum and 802.11ah supporting 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to representative embodiments, 802.11ah can support meter-type control / machine-type communications, such as MTC devices in macro coverage areas. MTC devices can have limited functionality, including support for some and / or limited bandwidths (e.g., only support for them). MTC devices can include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0060] WLAN systems that can support multiple channels and channel bandwidths, such as 802.11n, 802.11ac, 802.11af, and 802.11ah, include a channel that can be designated as a primary channel. The primary channel can have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel can be set and / or limited by the STA that supports the smallest bandwidth operating mode among all STAs operating in the BSS. In an 802.11ah example, the primary channel can be 1 MHz wide for STAs (e.g., MTC-type devices) that support (e.g., only support) 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) setting can depend on the state of the primary channel. For example, if the primary channel is busy due to a STA (that only supports 1 MHz mode of operation) transmitting to the AP, the entire available frequency band may be considered busy even though most of the frequency band remains idle and available.

[0061] In the United States, the available frequency band that can be used by 802.11ah is 902MHz to 928MHz. In Korea, the available frequency band is 917.5MHz to 923.5MHz. In Japan, the available frequency band is 916.5MHz to 927.5MHz. The total bandwidth available for 802.11ah is 6MHz to 26MHz, depending on country regulations.

[0062] 1F is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As described above, the RAN 113 can communicate with the WTRUs 102a, 102b, 102c over the air interface 119 using NR radio technology. The RAN 113 can also communicate with the CN 115.

[0063] The RAN 113 may include gNBs 180a, 180b, and 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, and 180c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, and 102c over the air interface 119. In one embodiment, the gNBs 180a, 180b, and 180c may implement MIMO technology. For example, the gNBs 180a and 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, and 180c. Thus, for example, the gNB 180a 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, and 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, and 180c may implement Coordinated Multi-Point (CoMP) technology. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or 180c).

[0064] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with 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 the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of varying or scalable lengths (e.g., including different numbers of OFDM symbols and / or lasting different lengths of absolute time).

[0065] 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 a standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c without further access to another RAN (e.g., eNodeBs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c can utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c can communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect with the gNBs 180a, 180b, 180c while also communicating / connecting with another RAN, such as the eNodeBs 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNodeBs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNodeBs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput to serve the WTRUs 102a, 102b, 102c.

[0066] 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 UL and / or DL, support for network slicing, dual connectivity, interconnection between NR and E-UTRA, routing of user plane data towards user plane functions (UPFs) 184a, 184b, routing of control plane information towards access and mobility management functions (AMFs) 182a, 182b, and the like. As shown in FIG. 1F, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0067] 1F 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 is shown as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0068] 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 act as a control node. For example, the AMF 182a, 182b may handle authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling various PDU sessions with different requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, and the like. Network slicing can be used by the AMF 182a, 182b to customize CN ports for the WTRUs 102a, 102b, 102c based on the type of service utilized by the WTRUs 102a, 102b, 102c. For example, different network slices may be established for different use cases, such as services utilizing Ultra-Reliable Low-Latency (URLLC) access, services utilizing enhanced High-Capacity Mobile Broadband (eMBB) access, services for Machine Type Communications (MTC) access, and / or the like. The AMF 182 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) that use other radio technologies, such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies, such as WiFi.

[0069] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions such as managing and allocating IP addresses for WTRUs, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, and the like. The PDU session type may be IP-based, non-IP-based, Ethernet-based, and the like.

[0070] The UPFs 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 communication between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 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.

[0071] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that acts as an interface between the CN 115 and the PSTN 108. Additionally, the CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b via the UPFs 184a, 184b by an N3 interface to the UPFs 184a, 184b and by an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0072] While RAN 113 is disclosed herein as providing certain operations, it is also contemplated that gNBs 180a, 180b, and 180c included in RAN 113 may enable such operations.

[0073] Although the CN 115 is disclosed as providing several operations, it is also contemplated that the AMFs 182a, 182b, SMFs 183a, 183b, and / or UPFs 184a, 184b included in the CN 115 may enable such operations.

[0074] 1A-1D and the corresponding description thereof, one or more, or all, of the functions described herein with respect to one or more of the WTRUs 102a-d, base stations 114a-b, eNodeBs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-b, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices 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 functionality.

[0075] The emulation device may be designed to perform one or more tests of other devices in a laboratory environment and / or an operator network environment. For example, one or more emulation devices may perform one or more or all functions but be fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the communication network. One or more emulation devices may perform one or more or all functions but be temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device to perform testing and / or may perform testing using wireless communication over the air.

[0076] The one or more emulation devices may perform one or more functions, including all, but are not implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a test lab and / or in a test scenario in an undeployed (e.g., test) wired and / or wireless communication network to perform testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, e.g., one or more antennas) may be used by the emulation devices to transmit and / or receive data.

[0077] Although the WTRU is shown in Figures 1A-1F as a wireless terminal, it is also contemplated that in some representative embodiments such a terminal may use a wired communication interface with the communication network (e.g., temporarily or permanently).

[0078] In some representative embodiments, a MICO (Mobile Initiated connection Only) WTRU 102 may determine whether to perform a registration update, e.g., before an SR, according to a pre-configured flag, a flag provided in the network (NW) (e.g., NW 113 / 115), and / or other criteria, among others.

[0079] In some representative embodiments, the MICO WTRU 102 may include a temporary user ID (TUID) of the MICO WTRU 102 in the SR, which may enable WTRU information acquisition, for example, when the serving access and mobility management function (AMF) does not have a context (e.g., a WTRU context).

[0080] In some representative embodiments, the MICO WTRU 102 may read an identifier of the serving AMF (e.g., AMF 182a) from the broadcast system information and compare that identifier with one or more stored TUIDs to determine whether the MICO WTRU 102 has moved to a new AMF (e.g., AMF 182b).

[0081] In some representative embodiments, the MICO WTRU 102 may indicate a preference for initiating a connection from the MICO WTRU 102 itself, and the NW (e.g., NW 113 / 115) may refrain from disconnecting the MICO WTRU 102 (e.g., if such a preference is accepted).

[0082] In some representative embodiments, the MICO WTRU 102 may reject the RAN signaling, for example, to place the MICO WTRU 102 in RRC_INACTIVE mode, and the MICO WTRU 102 may remain in CONNECTED mode and / or go to IDLE mode.

[0083] If the NW (e.g., NW113 / 115) decides, desires, wants to, or intends to update configuration parameters for the MICO WTRU102 (e.g., Network Slice Selection Assistance Information (NSSAI), enhanced discontinuous reception (eDRX), and / or MICO periodic timer, among others), the NW113 / 115 may trigger the MICO WTRU102 to perform a registration procedure using an SR procedure. Typical MICO modes Mobile Originated Only (MOO) functions / procedures and / or features may be service requirements for machine-type communications (MTC). For example, the NW (e.g., NW 113 / 115) may reduce the frequency of mobility management procedures for MOO devices. A power save mode (PSM) function may handle MOO for infrequent, mobile-terminated service requirements. PSM mode may be equivalent to the WTRU 102 powering off while remaining registered. The WTRU 102 may exit PSM mode (e.g., only when) it has Mobile Originated (MO) data and / or signaling. When the WTRU 102 is in PSM mode, the WTRU 102 is not reachable.

[0084] A MICO mode WTRU 102 may not be reachable (e.g., may always be unreachable) while in CM-IDLE. The Core NW (CN) 115 may reject any requests for downlink data or signaling delivery to a MICO WTRU 102 in IDLE mode. A WTRU 102 in MICO mode may be reachable (e.g., only reachable) for mobile-terminated data and / or signaling when the MICO WTRU 102 is in CM-CONNECTED mode. The MICO WTRU 102 may initiate the procedure to switch from CM-IDLE mode to CM-CONNECTED mode due to any of the following triggers: (1) a change in the MICO WTRU 102 (e.g., a change in its configuration) that requires and / or may cause an update to the MICO WTRU registration with the NW 113 / 115, for example; (2) a registration timer that may expire (e.g., a periodic registration timer); (3) MO data that may be pending; and / or (4) MO signaling that may be pending (e.g., an SM procedure that may be initiated), among others.

[0085] The MICO WTRU 102 may negotiate with the NW 113 / 115 regarding whether the MICO WTRU 102 can enter MICO mode. The WTRU 102 may indicate a preference for MICO mode during initial registration and / or registration update. The AMF 182a may determine whether MICO mode is possible for the WTRU 102 based on (1) local configuration, (2) WTRU subscription information, (3) WTRU-indicated preferences, and / or (4) NW policy. The AMF 182a may indicate its decision (e.g., the MICO WTRU's decision) to the WTRU 102 during the registration procedure.

[0086] A "mobile deregistration at end of communication" function / procedure and / or mechanism may be implemented that allows the WTRU 102 to perform deregistration at the end of communication without further NAS signaling. The WTRU 102 may indicate a preference for deregistration at end of communication (DAEC) during the registration procedure. The AMF 182a may determine whether DAEC is supported for the WTRU and may indicate support for DAEC during registration signaling. When the AMF 182a applies DAEC to the WTRU 102, the AMF 182a may consider that the WTRU 102 may enter RM-DEREGISTERED upon release of the N2 connection for the WTRU 102, and that the WTRU 102 may move to RM-DEREGISTERED when leaving CM-CONNECTED mode. This type of WTRU 102 may share common characteristics with the MICO WTRU 102 in that both may be unreachable except in CONNECTED mode.

[0087] Although a MICO WTRU 102 is described hereinafter, various representative embodiments herein are equally applicable to other types of WTRUs 102 , including DAEC WTRUs 102 and other mobile WTRUs 102 .

[0088] In some exemplary embodiments, exemplary procedures may be implemented, for example, to enable the MICO WTRU 102 to be recognized in the serving AMF 182.

[0089] FIG. 2 is a diagram illustrating a representative MICO WTRU 102 moving to a new serving AMF 182b.

[0090] 2, in a representative network 200, a WTRU 102 may be located in a first registration area 210 including a first plurality of tracking areas TA1-TA4 and may be served by a first AMF 182a. The WTRU 102 may move to a second serving area 220 including a second plurality of tracking areas TA5-TA8, which may be served by a second AMF 182b. The WTRU 102 (e.g., a typical WTRU or a non-MICO WTRU) may be assigned to the first registration area 210 from which it is served, and may perform a registration area update when the WTRU 102 leaves its configured registration area (e.g., first registration area 210). The NW 113 / 115 may restrict a paging area to the WTRU 102's registration area 210 or 220. The MICO WTRU 102 is not expected to and / or does not receive paging in IDLE mode, and the normal registration area configuration may not be used for the MICO WTRU 102. A WTRU 102 in MICO mode (sometimes hereafter referred to as a MICO WTRU) may be assigned to an “all PLMN” registration area; therefore, the MICO WTRU 102 may not perform registration area updates (e.g., except for periodic registration updates) when the MICO WTRU 102 remains in the same registered PLMN. The MICO WTRU 102 may move to a new area that is not served by the first AMF 182a to which the MICO WTRU 102 was previously registered. For example, a new AMF (e.g., the second AMF 182b) may be selected to serve the MICO WTRU 102 when the MICO WTRU 102 initiates a connection (e.g., using an SR message and / or periodic registration updates). The new AMF (e.g., the second AMF 182b) may reject the SR or periodic registration update (e.g., because the new AMF 182b does not recognize the MICO WTRU 102), but it may trigger the MICO WTRU 102 to register again.

[0091] For example, the MICO WTRU 102 may first register with the old serving AMF 182a using the WTRU context via the gNB 180a. The MICO WTRU 102 may then move to a new area where it has no registration. The MICO WTRU 102 may then send an SR to the new serving AMF 182b via the new gNB 180c. Finally, the AMF may send a denial of service to the MICO WTRU 102 via the gNB 180c, for example, because the AMF 182b does not recognize the MICO WTRU 102.

[0092] If this scenario occurs frequently (e.g., more frequently than a threshold level), the "denial of service, then re-registration" approach may significantly delay mobile-initiated communications and may impose extra signaling overhead on the NW 113 / 115.

[0093] For example, to avoid denial of service and to avoid extra signaling overhead, registration may be performed by the MICO WTRU 102 before SR. The MICO WTRU 102 is provided by the NW 113 / 115 with a serving AMF (WSA) area, which may be a list of tracking areas, for example, enabling the MICO WTRU 102 to determine whether it is within (e.g., still inside) the serving area of ​​the registered AMF 182a. When (e.g., only when) the MICO WTRU 102 determines that it is outside the serving area of ​​the registered AMF 182a, the MICO WTRU 102 may initiate a registration procedure before generating any communications. Typical Procedure for Keeping a MICO WTRU in CONNECTED Mode In general, the RAN 113 (e.g., including one or more gNBs 180) may initiate a detach due to one or more conditions, such as inactivity (e.g., user inactivity) and / or radio communication failure. For example, the RAN 113 may maintain an inactivity timer for the WTRU 102, and if no data activity is detected before the timer expires, the RAN 113 may initiate a detach. When in MICO mode, the WTRU 102 is reachable only in CONNECTED mode. If the detach is premature and data is still pending, there would be no way to return the MICO WTRU 102 to CONNECTED mode until the next time the MICO WTRU 102 initiates a connection. In some representative embodiments, a WTRU 102 in MICO mode may make the detach decision. In other representative embodiments, the NW 113 / 115 may maintain the MICO WTRU 102 in CONNECTED mode longer under certain criteria (e.g., when the NW 113 / 115 determines that a longer connection is appropriate and / or necessary).

[0094] The AMF 182a may maintain a connection timer for the MICO WTRU 102. When the RAN 113's inactivity timer expires, the RAN 113 may request release of the N2 connection (e.g., the signaling connection between the RAN 113 and the AMF 182a). If the AMF 182a determines that the MICO WTRU connection should not be released due to its own connection timer, the AMF 182a may deny the RAN 113's release request, and the RAN 113 may maintain the MICO WTRU 102 in CONNECTED mode. In some representative embodiments, procedures may be implemented to make the AMF 182a aware of the WTRU's data activity, for example, to enable the AMF 182a to maintain the connection and / or inactivity timers. In some representative embodiments, when the RAN 113 requests to release the N2 connection, a procedure may be implemented to prevent the RAN 113 from initiating the RRC disconnection, for example, by the AMF 182a providing the RAN 113 with WTRU-specific inactivity information (e.g., timer information). Typical Procedures to Prevent a MICO WTRU from Entering RRC Inactivity Mode FIG. 3 is a diagram illustrating exemplary states, including an exemplary RRC_INACTIVE state (e.g., a new RRC_INACTIVE state), in a 5G new radio (e.g., for a WTRU 102).

[0095] 3, in the RAN 113 (e.g., a 5G RAN), the RRC states 300 may include any of (1) an RRC_CONNECTED state 310, (2) an RRC_INACTIVE state 320, and / or (3) an RRC_IDLE state 330, among others. For a WTRU 102 in the INACTIVE state 320, the core network-access network (CN-AN) connection may be maintained as in the CONNECTED state 310. The CN-AN connection may be between the RAN and the CN and may have both a control plane (CP) (e.g., an N2 interface in 5G for signaling) connection and a user plane (UP) (e.g., an N3 interface in 5G for data) connection. A WTRU 102 in the INACTIVE state 320 may behave more like a WTRU in IDLE mode. For example, a WTRU 102 in the INACTIVE state 320 may follow cell selection / reselection procedures when the WTRU 102 changes cells. The CN 115 may not recognize the INACTIVE state 320 of the WTRU 102 and continues to consider the WTRU 102 to be in the CONNECTED state 310; therefore, CN paging should not be performed towards the INACTIVE WTRU 102. For example, to enable proper paging of the MICO WTRU 102, a procedure may be performed by the CN 115 to determine that the WTRU 102 is in the INACTIVE state 320 and not in the CONNECTED state 310. As an example, when downlink (DL) data is received from the CN 115, the anchor RAN 113 may initiate paging and manage a RAN paging area for the INACTIVE WTRU 102. In some representative embodiments, conditions may be indicated that trigger a state switch between the RRC_INACTIVE state 320 and one of two other states 310 or 330.

[0096] The benefits of having the INACTIVE state 320 may include power savings and reduced signaling overhead (e.g., resulting from frequent RRC_IDLE⇔RRC_CONNECTED switching). For a MICO WTRU 102, both the power savings and signaling reduction benefits may not be useful and / or necessary, and placing the MICO WTRU 102 in the RRC_INACTIVE mode / state 320 may incur potential technical complications. Therefore, in some representative embodiments, the MICO WTRU 102 may be prevented from entering the RRC_INACTIVE state 320. Representative Procedure with Long Periodic Timer (e.g., to prevent WTRU from performing registration updates) When the WTRU 102 notifies the NW 113 / 115 of some configuration changes or negotiates some parameters, the WTRU 102 may trigger some registration update procedures, such as a routing area update (RAU) and / or a tracking area update (TAU). A registration update may be performed, for example, for the WTRU 102 to notify the NW 113 / 115 of some internal changes, including either (1) a DRX cycle and / or (2) some functional parameters, among others. When the WTRU 102 triggers the RAU and / or TAU procedures, the NW 113 / 115 may reply with an “Accept” message. A “handshake” may act as a negotiation between the two entities.

[0097] For 5G systems, it is also contemplated that there may be scenarios / situations in which the WTRU 102 (e.g., a MICO WTRU) may not have an opportunity to initiate a registration update procedure (e.g., when the WTRU 102 has a long periodic registration timer). If the periodic registration timer is running during IDLE mode 330 (because the WTRU 102 can only send a registration update message when the periodic timer expires), the WTRU 102 may send an SR message. The periodic registration timer may be reset when the WTRU 102 returns to IDLE mode 330. The same situation may occur while the periodic timer is running. The WTRU 102 may not be able to perform the registration procedure for an extended period of time. In some representative embodiments, a procedure may be performed for the WTRU 102 to negotiate with the NW 113 / 115 in the event of some internal configuration change and / or any other reason. Typical Procedures for a MICO WTRU with an "All PLMN" Registration Area When a MICO WTRU 102 configured with an “all PLMN” registration area moves to a new area that is outside the serving area (e.g., range) of its registered AMF 182a, the MO connection request (e.g., SR) may be rejected by the new serving AMF 182b, and the WTRU 102 may need to register with the new AMF 182b before the WTRU 102 can communicate. If the MICO WTRU 102 always performs a proactive re-registration before an SR, e.g., to avoid a possible denial of service, signaling may be wasted if the WTRU 102 is still within the serving area 210 of the registered AMF 182a. In some representative embodiments, procedures may be implemented to ensure, for example, that unnecessary re-registration does not occur frequently.

[0098] In some representative embodiments, the MICO WTRU 102 may receive an indication from a NW entity (e.g., of the NW 113 / 115) that the MICO WTRU 102 should (e.g., always) or will perform a registration procedure prior to a connection request. The indication may be sent in the same registration accept message that confirms MICO mode to the WTRU 102. The NW 113 / 115 may choose to set the indication when the NW 113 / 115 configures an "all PLMN" registration area for the MICO WTRU 102. To set the indication, any of the following may be taken into consideration: (1) If the profile of the WTRU 102 indicates that the WTRU 102's communication (the WTRU 102's need and / or use for communication) is likely to be infrequent or infrequent (e.g., very infrequent or below a threshold level), the NW 113 / 115 and / or NW entities 180, 182-184 may choose to set and / or can set an indication. A re-registration procedure before a connection request may not be necessary and / or appropriate, but may be acceptable (e.g., because a re-registration procedure should not or does not occur frequently (e.g., above a threshold level)). In some representative embodiments, the profile of the WTRU 102 may indicate that the WTRU's need for communication is likely to be frequent, and the NW 113 / 115 (e.g., NW entities 180, 182-185) should not or will not set an indication.

[0099] (2) If the “mobility pattern” of the WTRU 102 indicates that the WTRU 102 moves frequently and the roaming range of the WTRU 102 exceeds the serving area 210 of the AMF 182a (e.g., it may mean that the WTRU 102 is likely to be outside the serving area 210 of the AMF 182a, e.g., above a threshold rate), the NW 113 / 115 and / or NW entities 180, 182, 183, 184, and / or 185 may set (e.g., choose to set) an indication. If the mobility pattern of the WTRU 102 indicates that the WTRU 102 is stationary, substantially stationary, and / or roams (e.g., only roams) within an area (limited area), the NW 113 / 115 and / or NW entities 180, 182, 183, 184, and / or 185 may not set an indication.

[0100] FIG. 4 illustrates an exemplary registration procedure 400, in which the NW 113 / 115 (e.g., the AMF 182a, or another NW entity 182-185) may provide an "always register before service request" (always RBSR) indication to the WTRU 102.

[0101] 4, at 410, the WTRU 102 may send a registration request to the AMF 182a including information indicating an MICO mode preference. At 420, the AMF 182a may look up the WTRU profile, mobility pattern, and other information about the WTRU 102. At 430, the AMF 182a may send a registration accept including information indicating that MICO mode has been accepted and an always RBSR indication to the WTRU 102. In some representative embodiments, the always RBSR indication may be pre-configured in the MICO WTRU 102, for example. The WTRU 102 may include the pre-configured indication along with the MICO mode preference during the registration procedure.

[0102] For example, if the WTRU 102 is in MICO mode and this Always RBSR indication is set by signaling from the NW 113 / 115 (e.g., the AMF 182 and / or other NW entities 183-185) and / or by pre-configuration, the WTRU 102 may examine the following criteria to determine whether the WTRU 102 can or should implement RBSR (e.g., Always RBSR):

[0103] The NW 113 / 115 (e.g., the AMF 182) and / or the WTRU 102 can determine whether the WTRU 102 is configured with an "all PLMN" registration area. If the NW 113 / 115 and / or the WTRU 102 determines that the WTRU 102 is not configured with an "all PLMN" registration area, the WTRU 102 cannot (e.g., cannot necessarily) perform RBSR (e.g., always RBSR). For example, the WTRU 102 cannot send a registration request with MICO preferences, and / or the AMF 182, which performs a lookup of the WTRU 102's profile, cannot send a registration accept that includes (1) an indication that MICO mode is accepted and / or (2) an indication of always RBSR.

[0104] The WTRU 102 may determine whether the WTRU 102 is moving (e.g., has actually moved) out of its tracking area (TA) (e.g., the WTRU 102 is moving (e.g., has just moved) from a previous TA to a new TA). The WTRU 102 may read the TA identifier of the current TA when the WTRU 102 activates for Mobile Originated Services and compare the current TA identifier (e.g., read) with the stored TA identifier. If the current TA identifier and the stored TA identifier are the same, the WTRU 102 may not have moved out of the TA in which the WTRU 102 previously registered with the NW 113 / 115 (e.g., the AMF 182 or other NW entities 183-185). The WTRU 102 may not be able to register again, for example, because the WTRU 102 is still within the service area of ​​the AMF 182 in which it previously registered.

[0105] If the WTRU 102 determines that it can or should perform a registration update procedure before the SR, the WTRU 102 may initiate registration with a flag (e.g., an "active flag") that may indicate that data may be pending or after the registration procedure, in which case a subsequent SR message may not be sent.

[0106] FIG. 5 illustrates an exemplary decision procedure 500 (e.g., for a MICO WTRU 102 to determine (e.g., determine) whether registration should, can, or will occur before SR).

[0107] 5, an exemplary decision procedure 500 may include, at block 510, receiving a connection request from an upper layer at the WTRU 102. At block 520, the WTRU 102 may determine whether an SR is desirable and / or needs to be sent to the NW 113 / 115 based on the connection request. If an SR is undesirable and / or does not need to be sent to the NW 113 / 115, the WTRU 102 may send one or more periodic registration updates at block 530. If an SR is desirable and / or needs to be sent to the NW 113 / 115, the WTRU 102 may determine whether MICO mode is configured at block 540. If MICO mode is not configured, processing proceeds to block 585 and sends an SR. If MICO mode is configured, the WTRU 102 may determine whether an “all PLMN” registration area is configured at block 550. If an "all PLMN" registration area is not set, the process proceeds to block 585 and sends an SR. If an "all PLMN" registration area is set, the WTRU 102 may determine whether an "always-register" indication is set in block 560. If the always-register indication is not set in block 560, the process proceeds to block 585 and sends an SR. If the always-register indication is set, the tracking area ID may be read (e.g., the most recent tracking area ID may be read) in block 565. In block 570, the WTRU 102 may compare the most recent tracking area ID to a stored tracking area ID to determine whether a match exists. If a match exists in block 570, the process proceeds to block 585 and sends an SR (e.g., without any prior registration update) (because the WTRU 102 is still in a tracking area with which the NW 113 / 115 can associate with the WTRU 102). If a match does not exist, the WTRU 102 may store the most recent tracking area in block 575.At block 580, the WTRU 102 may register the WTRU 102 with the NW 113 / 115 (because the WTRU 102 is no longer within a tracking area that the NW 113 / 115 associated with the WTRU 102, thus potentially resulting in denial of service). At block 585, the WTRU 102 may send an SR to the NW 113 / 115.

[0108] FIG. 6 illustrates another exemplary decision procedure for determining whether registration should, can, or will occur prior to SR.

[0109] 6, an exemplary decision procedure 600 may include, at block 610, receiving a connection request from an upper layer at the WTRU 102. At block 620, the WTRU 102 may determine that an SR is desirable and / or needs to be sent to the NW 113 / 115 based on the connection request. At block 630, the WTRU 102 may determine whether MICO mode is configured. If MICO mode is configured, then at block 640, the WTRU 102 may determine that an “all PLMN” registration area is configured. If MICO mode is not configured, processing may proceed to block 690, where an SR may be sent to the NW 113 / 115 (e.g., without any prior registration update). If an “all PLMN” registration area is configured, then at block 650, the WTRU 102 may determine whether an “always register” indication is configured. If an all-PLMN registration area is not set, the process proceeds to block 660, where a tracking area ID may be received from broadcast system information and / or a Mobile Originated Operation. If the "always register" indication is not set, the process proceeds to block 690, where an SR may be sent to the NW 113 / 115 (e.g., without any prior registration update). If the "always register" indication is set, or if the process proceeds to block 660 from block 640, a tracking area ID is received and / or read from broadcast system information and / or a Mobile Originated Operation. At block 670, the WTRU 102 may compare the received / read tracking area ID with one or more stored tracking area IDs to determine whether a match exists. If a match exists at block 670, the process proceeds to block 690, where an SR is sent (e.g., without any prior registration update) (because the WTRU 102 is still within a tracking area that the NW 113 / 115 can associate with the WTRU 102). If there is no match, then at block 680 the WTRU may store the received tracking area ID.At block 685, the WTRU 102 may register the WTRU 102 with the NW 113 / 115 (as the WTRU 102 may no longer be within a tracking area that the NW 113 / 115 may associate with the WTRU 102, thus potentially resulting in denial of service). At block 690, the WTRU 102 may send an SR to the NW 113 / 115.

[0110] Although the determination of whether a WTRU is within a registration area is disclosed as being based on a Tracking Area Identifier (TA ID), those skilled in the art will appreciate that it may be based on an AMF ID in addition to or instead of the TA ID. For example, a received AMF identifier (ID) may match one or more stored AMF IDs to provide a similar registration area determination.

[0111] In some representative embodiments, the MICO WTRU 102 may include a MICO mode indication and / or the TUID of the MICO WTRU 102 in the SR message. In other representative embodiments, the TUID included in the SR may simultaneously indicate a MICO mode indication (e.g., a MICO mode preference). In a legacy WTRU 102, triggering an SR procedure is based on whether the WTRU 102 is "registered" with a TA (e.g., on a TA list). The legacy WTRU 102 does not provide any "area information" to the CN 115 when initiating an SR procedure.

[0112] In some representative embodiments, the WTRU 102 can or will add the WTRU 102's previous TA identifier to the SR message. If the WTRU 102 was allocated a TUID by the same AMF 182a, the added previous TA identifier allows the AMF 182a to identify (e.g., uniquely identify) the WTRU 102. If the serving AMF 182b is a new AMF (e.g., the serving AMF 182b has not previously served the WTRU 102) and / or does not have a context for the WTRU 102, the new AMF 182b should not reject the SR if it receives (1) a MICO indication, (2) a TUID, and / or (3) a TA identifier where the WTRU 102 was allocated a TUID.

[0113] The new AMF 182b can map the information (e.g., all of the information) to the address of the old AMF 182a and can obtain the WTRU context from the old AMF 182a, which may be derived from the TUID. The new AMF 182b can reassign a new TUID to the WTRU 102 after the SR procedure is processed.

[0114] FIG. 7 illustrates a typical SR-triggered WTRU context acquisition procedure from the old AMF 182a (eg, from the AMF that previously served the WTRU 102).

[0115] 7, an SR-triggered WTRU context acquisition procedure 700 may include the WTRU 102 sending an SR including, for example, a MICO mode indication (e.g., MICO preference) and / or a TUID, toward the new AMF 182b serving the WTRU 102, at 720. The RAN 113 (e.g., the gNB 180) may forward information from the SR to the new AMF 182b via an N2 message at 730. The new AMF 182b may send an information request including the TUID of the WTRU 102 to the old AMF 182a at 740. The old AMF 182a may send an information response including, for example, a Subscriber Permanent Identity (SUPI) (which may be similar to an IMSI) and / or a mobility management (MM) context (e.g., a collection of information related to mobility management of the UE). At 760, authentication / security operations may be performed between the WTRU 102 and the new AMF 182b, and between the new AMF 182b and an authentication server function (AUSF) 710 (eg, a network function capable of handling WTRU authentication).

[0116] At 770, the new AMF 182b may send an N2 message to the RAN 113. The N2 message may include information that is sent to the WTRU 102 via the RAN 113 to enable RRC connection reconfiguration. At 780, the RAN 113 may send an RRC connection reconfiguration to the WTRU 102 based on the N2 message. At 790, the new AMF 182b may send a WTRU configuration including a new TUID towards the WTRU 102 via the RAN 113. At 795, the RAN 113 may forward the WTRU configuration to the WTRU 102.

[0117] In some representative embodiments, the RAN 113 in the NW 113 / 115 may broadcast a list of identifiers of AMFs 182 whose serving areas cover the RAN 113. The identifiers of the AMFs 182 may be broadcast in whole or in part. If an AMF identifier is present in the broadcast information of a RAN 113, that RAN 113 is within the serving area of ​​the AMF 182.

[0118] If the MICO WTRU 102 has a pending SR, it may read (e.g., first read) AMF identifiers from information broadcasted in the RAN and compare these AMF identifiers with the AMF ID section of the stored TUID. The AMF ID in the TUID is associated with the AMF 182 that the WTRU 102 registered on if the same AMF ID appears in the current RAN broadcast information and the WTRU 102 is within (still within) the serving area of ​​the AMF 182 that the WTRU 102 last registered on. In this case, the WTRU 102 may, for example, immediately (e.g., immediately) send the SR. In some representative embodiments, the WTRU 102 may initiate a registration procedure prior to or before sending the SR (e.g., first initiate the registration procedure and then send the SR, e.g., only send the SR after the WTRU 102 registers).

[0119] FIG. 8 is a diagram illustrating the registration / SR procedure.

[0120] 8, a registration / SR procedure 800 may include, at block 810, receiving a connection request from upper layers at the WTRU 102. At block 820, the WTRU 102 may determine whether it is desirable and / or necessary to send an SR to the NW 113 / 115 based on the connection request. If it is undesirable and / or necessary to send an SR to the NW 113 / 115, the WTRU 102 may send one or more periodic registration updates at block 830. If it is desirable and / or necessary to send an SR to the NW 113 / 115, the WTRU 102 may determine whether MICO mode is configured at block 840. If MICO mode is not configured, processing may proceed to block 890, where an SR may be sent. If MICO mode is configured, the WTRU 102 may determine whether an "all-PLMN" registration area is configured at block 850. If an "all PLMN" registration area is not configured, processing continues to block 890, where an SR may be sent. If an "all PLMN" registration area is configured, the WTRU 102 may read the AMF ID from the broadcast system information at block 860. At block 870, the WTRU 102 may compare the read AMF ID associated with the TUID with the AMF IDs from the broadcast system information (e.g., in an AMF ID list) to determine whether the AMF ID associated with the WTRU 102's TUID is in the list.

[0121] If, at block 870, the AMF ID of the AMF 182 associated with the WTRU's TUID is in the list, processing proceeds to block 890, where an SR may be sent (e.g., without any prior registration update) (because the WTRU 102 is still served by one of the AMFs 182 broadcasted, for example, in the system information). If the AMF ID associated with the WTRU 102's TUID is not in the list, at block 880, the WTRU 102 may register with the NW 113 / 115 (because the WTRU 102 may no longer be served by the AMF 182 corresponding to the AMF ID on the list, thus potentially resulting in a denial of service). At block 890, the WTRU 102 may send an SR to the NW 113 / 115 (e.g., the AMF 182).

[0122] For example, the WTRU 102 may determine whether the WTRU 102 is within the AMF service area 210 or 220 by reading the AMF ID in the system information (SI).

[0123] In some representative embodiments, the MICO WTRU 102 may start or restart a timer after registration (e.g., each registration, including periodic registration updates). The length of the timer may indicate the time period since the last registration (e.g., during which the WTRU 102 is likely to be within (still within) the service area 210 or 220 of the AMF 182a or 182b with which it registered). When the MICO WTRU 102 needs to or is about to send an SR, the MICO WTRU 102 may check whether the timer is running. If the timer is running, the WTRU 102 is likely to be within the same service area 210 or 220 of the AMF 182a or 182b with which it last registered (e.g., very high above a threshold level), and the MICO WTRU 102 may send an SR, for example, immediately and / or immediately. In some representative embodiments, the WTRU 102 may be or likely to be outside the coverage area 210 or 220 of the AMF 182a or 182b with which it last registered, and the MICO WTRU 102 may (e.g., may need to) perform registration again before sending the SR. The length of the timer may be pre-configured in the WTRU 102 or may be provided by the NW 113 / 115 (e.g., the AMF 182 or other NW entities 180 and 183-185). Typical Procedure for Keeping a MICO WTRU in Connected Mode To keep the MICO WTRU 102 in CONNECTED mode longer (e.g., moderately long or longer than a threshold period), the NW 113 / 115 (e.g., the AMF 182 or other NW entities 180, 183-185) may determine that the WTRU 102 has a requirement (e.g., to remain in CONNECTED mode). The NW 113 / 115 may have difficulty making this decision based on the WTRU profile. Certain assistance information from the WTRU 102 may be used in this decision.

[0124] In some embodiments, the MICO WTRU 102 may include an indication of service characteristics in the SR that enables the NW 113 / 115 to determine that the WTRU 102 will or needs to remain in CONNECTED mode longer than normal. The indication of service characteristics may include, among other things, (1) a delay tolerance and / or a “high level of delay tolerance” indicator and / or (2) a latency value and / or a “high latency” indication, and may provide thresholds that may be, for example, (1) WTRU-specific, (2) application-specific, (3) service-specific, and / or (4) class-specific (e.g., device class-specific), among other things. For example, a particular WTRU 102 may have, among other things, a specific delay tolerance, a specific latency, a specific application running, a specific service requirement, and / or a service device class, which may be taken into account when the MICO WTRU 102 is in CONNECTED mode (e.g., to avoid prematurely moving to another mode (e.g., disconnecting, etc.)).

[0125] In some representative embodiments, the MICO WTRU 102 may include information or a flag in the SR indicating a preference that detachment can or will be initiated by the WTRU 102 itself and not by a NW (e.g., the RAN 113 or the CN 115). After receiving the SR with the preference indication, the NW 113 / 115 may determine whether to allow the WTRU 102 to initiate detachment (e.g., whether the RAN 113 or the NW 113 / 115 may allow the WTRU 102 to initiate it) based on the WTRU subscription data and / or NW policy. If detachment by the WTRU 102 is accepted, the NW (e.g., the CN 115 or the RAN 113) may instruct the other of the RAN 113 or the CN 115 not to initiate detachment for the WTRU 102. When the WTRU 102 autonomously (e.g., by itself) determines that the WTRU 102 has finished data communication, the WTRU 102 may initiate detachment via either (1) an NAS procedure and / or (2) an RRC procedure. The WTRU 102 may start a timer after the WTRU 102 enters CONNECTED mode. If the timer expires and the WTRU 102's data communication has not completed and / or the WTRU 102 cannot determine whether the data communication has completed, the WTRU 102 may and / or will initiate detachment (e.g., detachment anyway).

[0126] FIG. 9 illustrates a typical MICO WTRU initiated disconnection procedure.

[0127] 9, an exemplary MICO WTRU-initiated detachment procedure 900 may include, at 910, registration between the AMF 182a and the MICO WTRU 102 via the RAN 113. The registration may include MICO mode information indicating that the WTRU is in MICO mode. At 920, the MICO WTRU may send an SR to the AMF 182a via the RAN 113, and the WTRU 102 may include information indicating that it prefers WTRU-initiated detachment (e.g., to reduce and / or substantially eliminate premature detachment by the NW 113 / 115). At 930, the NW 113 / 115 (e.g., via the AMF 182a) may accept the WTRU's preferences in accordance with and / or based on the MICO WTRU 102's profile and one or more network policies. At 940, the AMF 182a may send an N2 message to the RAN 113 (e.g., the gNB 180) to establish a preference (e.g., for WTRU-initiated detachment). At 950, the MICO WTRU 102 may determine that the data communication is complete. In some representative embodiments, at 960, 970, and 980, the WTRU 102 may initiate and complete the detachment via NAS-initiated messages. In other representative embodiments, at 985 and 990, the WTRU 102 may initiate and complete the detachment via RRC-initiated messages.

[0128] In a first option, the WTRU 102 may send 960 an NAS release request to the AMF 182a via the RAN 113. At 970, an N2 disconnection is performed between the AMF 182a and the RAN 113. At 980, the RAN 113 may send an RRC disconnection to the WTRU 102 to release the RRC connection. In a second option, the WTRU 102 may send 985 an RRC disconnection request to the RAN 113. At 990, an N2 disconnection is performed between the AMF 182a and the RAN 113.

[0129] At 995, the MICO WTRU 102 may enter RRC_IDLE mode after the first option or the second option is completed.

[0130] In some representative embodiments, the MICO WTRU 102 may include information in the SR indicating a preferred "inactivity time period" before it may be disconnected. The NW 113 / 115 may determine whether the WTRU 102's preferred inactivity period indicated in the SR is acceptable based on the WTRU subscription data and / or NW policy. If the WTRU's preferred inactivity period indicated in the SR is acceptable, the NW (e.g., CN 115) may instruct the RAN 113 to set an "inactivity timer" based on the preferred inactivity period value.

[0131] The exemplary procedures described herein may be applied to MICO WTRUs that perform deregistration at the end of a communication. Typical procedure to prevent MICO WTRU from entering RRC_INACTIVE state FIG. 10 illustrates an exemplary procedure by which the RAN becomes aware of the MICO mode of a WTRU via N2 signaling.

[0132] 10 , in an exemplary procedure 1000, at 1010, registration is performed between the AMF 182a and the MICO WTRU 102 via the RAN 113. The registration may include MICO mode information indicating that the WTRU is in MICO mode. At 1020, the MICO WTRU 102 may send an RRC connection request to the RAN 113. At 1030, the RAN 113 may send an RRC connection setup to the WTRU 102. At 1040, the MICO WTRU 102 may send an RRC connection setup complete to the RAN 113, which may include an SR. At 1050, the RAN 113 may send the SR to the NW (e.g., the AMF 182a). At 1060, the AMF 182a may send an N2 message to the RAN 113. The N2 message may include MICO mode information, which may indicate that the WTRU 102 is in MICO mode. At 1070, the RAN 113 may store the MICO mode indication in the WTRU context. At 1080, the RAN 113 may send an RRC connection reconfiguration to the WTRU 102.

[0133] For example, the RAN 113 may be informed of the MICO mode of the WTRU 102 by N2 signaling (e.g., by an indicator or other information by the CN 115) during the SR procedure. The RAN 113 may store the indication and / or information in its WTRU context and may refrain from triggering a state switch to the RRC_INACTIVE state for the WTRU 102.

[0134] In some representative embodiments, a WTRU 102 in MICO mode may include a MICO mode indication in an RRC connection establishment request message if the RRC connection request is triggered, for example, by a pending SR. If the RRC connection request is triggered by non-service request signaling (e.g., by a periodic registration update, among others), the MICO mode may be changed after the registration procedure finishes and / or completes. In some representative embodiments, such as for those triggered by non-SR signaling, the WTRU 102 may not include a MICO mode indication in the RRC connection request.

[0135] FIG. 11 shows an exemplary procedure for a MICO WTRU 102 to accept or reject RAN signaling (eg, which would place the MICO WTRU 102 in an INACTIVE state).

[0136] 11 , in an exemplary procedure 1100, registration is performed between the AMF 182a and the MICO WTRU 102 via the RAN 113 at 1110. The registration may include MICO mode information indicating that the WTRU 102 is in MICO mode. An RRC connection may be established between the WTRU 102 and the RAN 113 at 1120. The RAN 113 may decide to place the WTRU in an INACTIVE state (e.g., RRC_INACTIVE) at 1130 according to some criteria (e.g., an inactivity timer, etc.). The RAN 113 may send an RRC detach to the WTRU 102 at 1140, including information indicating a switch to the RRC_INACTIVE state. In some exemplary embodiments, the WTRU 102 may reject the detach at 1150 and 1160. In other exemplary embodiments, the WTRU 102 may accept the detach at 1170, 1180, and 1190.

[0137] In a first option, at 1150, the WTRU 102 may send an RRC Disconnect Reject to the RAN 113. The RRC Disconnect Reject may include a cause code indicating "MICO mode." At 1160, the WTRU 102 remains in connected mode.

[0138] In a second option, the WTRU 102 may send an RRC Disconnect Complete to the RAN 113 at 1170. The RRC Disconnect Complete may include information indicating that the WTRU has entered RRC_IDLE mode. At 1180, an N2 Disconnect is performed between the AMF 182a and the RAN 113. At 1190, the WTRU 102 may enter RRC_IDLE mode.

[0139] In some representative embodiments, the RAN 113 may not be aware of the WTRU 102's MICO mode and may initiate a request (e.g., via RRC signaling with an RRC_INACTIVE state switch command) to enter and / or place the WTRU 102 in RRC_INACTIVE mode. A WTRU 102 in MICO mode may deny the request (e.g., with a cause of "MICO mode") and the WTRU 102 may remain in RRC_CONNECTED mode. In various representative embodiments, the WTRU 102 may enter (e.g., directly enter) RRC_IDLE mode upon or after the request to enter RRC_INACTIVE, and the WTRU 102 may send a response message to the RAN 113 indicating that it intends to enter RRC_IDLE mode. Upon or after receiving the response message by the RAN 113, the RAN 113 may initiate N2 detachment towards the CN 115.

[0140] The exemplary procedures described herein are applicable to MICO WTRUs 102 that perform deregistration at the end of a communication.

[0141] Typical steps to trigger the registration procedure In some representative embodiments, a “handshake” (e.g., a new handshake) may be achieved between the WTRU 102 and the NW 113 / 115 during the SR procedure. The WTRU 102 can or will indicate to the NW 113 / 115 that it wishes to inform the NW 113 / 115 of some configuration changes and / or parameters in addition to or instead of the normal and / or traditional purpose of the SR message, for example, by inserting a flag in the SR message. For example, a new information element may be defined to serve this purpose (e.g., to indicate or inform the NW 113 / 115 of the configuration changes / parameters). On the NW side, in addition to processing the normal SR message, the NW 113 / 115 may respond with a service accept message to the WTRU 102 to complete the negotiation / handshake. It is contemplated that these procedures / mechanisms described herein may be implemented as new features, e.g., in 5G, or may be achieved by the WTRU 102 and NW 113 / 115 informing each other of their support during initial registration (e.g., during attach or initial registration).

[0142] If the NW 113 / 115 wants to and / or plans to update configuration parameters for the WTRU 102 (e.g., NW Slice Selection Assistance Information (NSSAI), eDRX, and / or MICO periodic timer, among others), the NW 113 / 115 can use the SR procedure to trigger the WTRU 102 to perform a registration procedure. The NW 113 / 115 can include an explicit indication in the service accept or reject message that informs the WTRU 102 that certain configuration parameters will and / or need to be updated (e.g., using a cause code in the reject message). Receiving a flag in the service accept or reject message can cause the WTRU 102 to perform the registration procedure. In some representative embodiments, the NW 113 / 115 (e.g., AMF 182) can send the configuration parameters that will and / or need to be updated in the service accept or reject message. If the WTRU 102 receives new configuration parameters in a service accept or reject message (eg, a service accept or reject NAS message), the WTRU 102 may perform a registration procedure.

[0143] FIG. 12 is a flow diagram illustrating an exemplary method for facilitating SR.

[0144] 12, the exemplary method 1200 may include the WTRU 102 performing a first registration with an NE (e.g., the AMF 182a, or another network device) at block 1210. The WTRU 102 may indicate to the NW 113 / 115 via the NE 182a that the WTRU 102 is operating in MICO mode. At block 1220, the WTRU 102 may determine whether the WTRU 102 is registered within an “all-PLMN” registration area. At block 1230, if the WTRU 102 operating in MICO mode is not registered in the “all PLMN” registration area, the WTRU 102 may determine whether it is outside the registration area associated with the first registration based on any of: (1) location-related information associated with the WTRU 102 received after the WTRU 102's first registration, (2) information from Mobile Originated (MO) services initiated after the WTRU 102's first registration with the NE 113 / 115, and / or (3) a network-provided flag. At block 1240, the WTRU 102 may send an SR. If, at block 1250, it is determined that the WTRU 102 is outside the registration area, the WTRU 102 may perform a second registration or registration update (e.g., with another NE (e.g., AMF 182b)) before the SR.

[0145] In some representative embodiments, the WTRU 102 may obtain information indicating that the WTRU 102 will initiate a second registration or registration update to send an SR. For example, the WTRU 102 may perform the second registration or registration update by sending a registration request according to the obtained information.

[0146] In some representative embodiments, the WTRU 102 may obtain the information through pre-configuration and / or through network signaling (eg, signaling by the network 113 / 115).

[0147] In some representative embodiments, the WTRU 102 may determine that the WTRU 102 is registered in an "all PLMN" registration area.

[0148] In some representative embodiments, the WTRU 102 may determine if the "always registered" indication is set if the WTRU 102 is registered in an "all PLMN" registration area.

[0149] In some representative embodiments, the WTRU 102 may send a registration request to perform a second registration (eg, update) before the SR if the "always register" indication is set.

[0150] In some representative embodiments, the WTRU 102 may obtain a tracking area (TA) identifier of the WTRU's TA indicated in the broadcast signal. For example, the WTRU 102 may determine whether the WTRU 102 is outside its registration area based on whether the obtained TA identifier (e.g., associated with the AMF 182a or 182b) matches a stored TA identifier associated with the NE that last served the WTRU 102 (e.g., associated with the AMF 182a), e.g., the WTRU 102 would therefore perform a second registration, or registration update, if the obtained TA identifier (e.g., associated with the AMF 182a or 182b) does not match the stored TA (e.g., associated with the AMF 182a).

[0151] In some representative embodiments, the WTRU 102 may obtain an identifier associated with the WTRU 102's registration area indicated in the broadcast signal. For example, the WTRU 102 may determine whether the WTRU 102 is outside the registration area based on whether the obtained identifier matches a stored identifier associated with the NE that last served the WTRU 102 (e.g., the AMF 182a or another NE 180, 183-185), and thus perform a second registration, or registration update, conditional on the obtained identifier not matching the stored identifier. In some representative embodiments, the identifier may be one of: (1) a tracking area identifier (e.g., one associated with the AMF serving the registration area), (2) a routing area identifier, or (3) an AMF identifier (e.g., one that identifies the AMF serving the registration area).

[0152] In some representative embodiments, the WTRU 102 may send the SR if the obtained TA identifier matches a stored TA identifier without any second registration or registration update before sending the SR.

[0153] FIG. 13 is a flow diagram illustrating another exemplary method for facilitating SR registration.

[0154] 13, an exemplary method 1300 performed by a WTRU 102 operating in MICO mode and registered in a first registration area may include the WTRU 102 determining whether the WTRU is outside (e.g., located outside) the first registration area based on either (1) information from the WTRU 102's most recent mobile-originated (MO) service or (2) a network-provided flag, at block 1310. The WTRU 102 may perform a registration update if it is determined that the WTRU 102 is outside the first registration area, at block 1320. The WTRU 102 may send an SR after the registration update, at block 1330.

[0155] FIG. 14 is a flow diagram illustrating another exemplary method for facilitating SR.

[0156] 14, the exemplary method 1400 may include the WTRU 102 performing a first registration with an NE (e.g., the AMF 182a) at block 1410. The WTRU 102 may indicate to the NW 113 / 115 via the NE (e.g., the AMF 182a) that the WTRU 102 is operating in MICO mode. At block 1420, the WTRU 102 may determine whether the WTRU is registered in an “all PLMN” registration area. At block 1430, the WTRU 102 may selectively perform a second registration or registration update before sending the SR based on the WTRU 102 not being registered in the “all PLMN” registration area and the WTRU 102 being outside the registration area associated with the first registration. At block 1440, the WTRU 102 may send the SR.

[0157] FIG. 15 is a flow diagram illustrating a further exemplary method for facilitating SR.

[0158] 15, the exemplary method 1500 may include the WTRU 102 sending an SR including WTRU-specific information, at block 1510. The WTRU-specific information may include (1) an indication that the WTRU 102 is operating in MICO mode and / or (2) a temporary user identifier (TUID) of the WTRU 102. At block 1520, the WTRU 102 may receive a connection reconfiguration message and a WTRU configuration message including a new TUID that differs from the TUID in the SR.

[0159] FIG. 16 is a flow diagram illustrating yet another exemplary method for facilitating SR.

[0160] 16, a representative method 1600 may include, at block 1610, the WTRU 102 receiving a broadcast signal indicating a network entity (NE) identifier associated with the NE (e.g., the AMF 182a or 182b) currently serving the WTRU 102. At block 1620, the WTRU 102 (e.g., the AS layer, the L1 layer, the L2 layer, the MAC layer, the physical layer, or another lower layer, among others) may receive a connection request from a higher layer (e.g., the NAS layer, another higher layer, among others). At block 1630, the WTRU 102 may determine, with a second layer (e.g., the AS layer, the L1 layer, the L2 layer, the MAC layer, the physical layer, or another lower layer, among others), whether the WTRU 102 is operating in MICO mode. At block 1640, if the WTRU 102 is operating in MICO mode, the WTRU 102 may determine whether the received NE identifier matches a stored NE identifier associated with the NE (e.g., AMF 182a) that last served the WTRU 102. At block 1650, the WTRU 102 may send an SR including WTRU-specific information if the received NE identifier (e.g., AMF 182a or 182b) matches the stored NE identifier (e.g., AMF 182a).

[0161] In some representative embodiments, the WTRU 102 may send a new registration or registration update before sending an SR if the received NE identifier (e.g., AMF 182a or 182b) does not match the stored NE identifier (e.g., AMF 182a).

[0162] FIG. 17 is a flow diagram illustrating yet another exemplary method for facilitating SR.

[0163] 17, the exemplary method 1700 includes the WTRU 102 obtaining information indicating that the WTRU will initiate registration before sending an SR, at block 1710. The WTRU 102 may send a registration request according to the obtained information, at block 1720. The WTRU 102 may send an SR after registering with the NE (e.g., the AMF 182b), at block 1730.

[0164] In some representative embodiments, the WTRU 102 may obtain the information through pre-configuration or through network signaling.

[0165] In some representative embodiments, the WTRU 102 may determine whether the WTRU 102 is operating in MICO mode, and may send a registration request before the SR if the WTRU 102 is operating in MICO mode.

[0166] In some representative embodiments, the WTRU 102 may determine whether the WTRU 102 is registered in an “all PLMN” registration area, and if the WTRU 102 is registered in the “all PLMN” registration area, may send a registration request before the SR.

[0167] In some representative embodiments, the WTRU 102 may receive broadcast signaling indicating a tracking area (TA) identifier of the WTRU 102's TA, may receive a connection request from an upper layer, and may determine, via a second layer, whether the WTRU 102 is operating in MICO mode.

[0168] In some representative embodiments, the WTRU 102 may at least determine whether the indicated TA identifier matches a stored TA identifier associated with the NE (e.g., AMF 182a) that was last serving the WTRU 102 when the WTRU 102 is operating in MICO mode, and may send an SR if the indicated TA identifier matches the stored TA identifier.

[0169] In some representative embodiments, the WTRU 102 may send a new registration or a registration update before sending the SR if the indicated TA identifier does not match the stored TA identifier.

[0170] FIG. 18 is a flow diagram illustrating yet another exemplary method for accepting or rejecting a disconnection.

[0171] 18, an exemplary method 1800 performed by a WTRU 102 in MICO mode may include, at block 1810, the WTRU 102 receiving a detach from an NE (e.g., gNB 180) of the RAN 113. At block 1820, the WTRU 102 may determine whether to accept the detach. At block 1830, if the WTRU 102 accepts the detach, the WTRU may (1) send a detach complete and (2) enter idle mode. At block 1840, if the WTRU 102 does not accept the detached mode, the WTRU 102 may (1) send a detach reject with a cause code indicating that the WTRU 102 is operating in MICO mode, and (2) remain in connected mode.

[0172] FIG. 19 is a flow diagram illustrating an exemplary method that may be implemented to facilitate registration.

[0173] 19 , a representative method 1900 performed by the WTRU 102 may include, at block 1910, the WTRU 102 sending a first message to an NE (e.g., the AMF 182, or another NE such as the gNB 180, or a CN entity 183-185). At block 1920, the WTRU 102 may obtain information indicating that the WTRU 102 will initiate registration. At block 1930, the WTRU may send a registration request according to the obtained information. For example, the obtained information may be a cause code or indication included in a second message from the NE 180 and 182-185. In some representative embodiments, the first message may be a service request, and / or the second message may be a service accept or service denial message. In various representative embodiments, the WTRU may perform a registration update and may update configuration parameters based on the registration update.

[0174] FIG. 20 is a flow diagram illustrating an exemplary method implemented by a NW to facilitate SR.

[0175] 20 , an exemplary method 2000 performed by a network entity (NE) (e.g., the AMF 182, or another NE such as the gNB 180, or the CN entities 183-185) may include, at block 2010, the NE 182 sending information indicating that the WTRU 102 will initiate registration before sending the SR. At block 2020, the NE 182 may receive a registration request according to the obtained information. At block 2030, the NE 113 / 115 may receive the SR after the WTRU 102 is registered.

[0176] FIG. 21 is a flow diagram illustrating another exemplary method performed by a NW when a WTRU is in MICO mode.

[0177] 21 , an exemplary method 2100 performed by an NE (e.g., the AMF 182 or other NEs 180, 183-185) of the NW 113 / 115 may include the NE 180, 182-185 determining whether the WTRU 102 is operating in MICO mode, at block 2110. If the WTRU 102 is operating in MICO mode, at block 2120, the NE 180, 182-185 of the NW 113 / 115 may negotiate with the WTRU 102 to (1) set an inactivity timer for a period longer than the period for the WTRU 102 that is not in MICO mode, (2) prevent disconnection of the WTRU 102 due to inactivity of the WTRU 102, and / or (3) configure the WTRU 102 to autonomously disconnect from the NE 180, 182-185 of the NW 113 / 115.

[0178] FIG. 22 is a flow diagram illustrating another exemplary method implemented by a NW to facilitate a connection request.

[0179] 22, an exemplary method 2200 performed by an NE of the NW 113 / 115 (e.g., the AMF 182b or another NE 180, 183-185) may include the NE 182b receiving a message requesting connection of the WTRU 102, including WTRU-specific information, at block 2210. The NE 182b may determine from the WTRU-specific information another NE (e.g., the AMF 182a) that last served the WTRU 102. At block 2230, the NE 182b may send an information request to the other NE (e.g., the AMF 182a) requesting information for connecting the WTRU 102 to the NE 182b.

[0180] In some representative embodiments, the NE 182b may receive request information to connect to the WTRU 102 from the other NE 182a, and may authenticate and connect to the WTRU 102 based on the information received from the other NE 182a.

[0181] In some representative embodiments, the WTRU-specific information may include either (1) an indication that the WTRU 102 is operating in MICO mode, and / or (2) a temporary user identifier (TUID) for the WTRU 102.

[0182] FIG. 23 is a flow diagram illustrating a further exemplary method implemented by a NW to facilitate SR.

[0183] 23 , an exemplary method 2300 performed by an NE (e.g., the AMF 182 or other NE 180, 183-185) of the NW 113 / 115 may include the NE 182 receiving a registration request to register the WTRU 102, the registration request including an indication that the WTRU is operating in MICO mode, at block 2310. After registration, the NE 182 may receive an SR from the WTRU 102 (e.g., via the RAN 113) including the WTRU 102's preference for WTRU-initiated detachment. At block 2330, the NE 182 may receive one of: (1) an NAS detach request from the WTRU 102 (e.g., via the RAN entity 180 of the RAN 113), or (2) an N2 detach (e.g., pursuant to an RRC detach request from the WTRU 102) from the RAN 113 (e.g., the gNB 180). For example, in one option, the WTRU 102 may send an RRC disconnect request to the RAN 113, and the RAN 113 may then perform an N2 disconnect with the AMF 182. At block 2340, the NE 182 may release the connection to the WTRU 102.

[0184] In some representative embodiments, the NE 182 may determine whether to accept the preference and may send the acceptance of the preference to a RAN entity (e.g., the gNB 180) of the RAN 113 that serves the WTRU 102.

[0185] In some representative embodiments, the NE 182 may look up either (1) the WTRU profile or (2) the WTRU mobility pattern.

[0186] FIG. 24 is a flow diagram illustrating an exemplary method implemented by a NW to facilitate registration.

[0187] 24, a representative method 2400 performed by an NE (e.g., the AMF 182, or another NE such as the gNB 180, or the CN entities 183-185) may include, at block 2410, the NE 180, 182-185 receiving a first message from the WTRU 102. At block 2420, the NE 180, 182-185 may determine that the WTRU will initiate registration. At block 2430, the NE 180, 182-185 may send information to the WTRU indicating that the WTRU will initiate registration. At block 2440, the WTRU may receive a registration request according to the sent information. For example, the sent information may be a cause code or indication included in a second message from the NE 180 and 182-185. In some representative embodiments, the first message may be a service request and / or the second message may be a service accept or service denial message.

[0188] FIG. 25 is a flow diagram illustrating an exemplary method performed by a RAN entity to facilitate SR.

[0189] 25, an exemplary method 2500 performed by a RAN entity (e.g., the gNB 180) of the RAN 113 includes, at block 2510, the RAN entity 180 receiving a message including an SR for the WTRU 102. Registration of the WTRU 102 with a network entity (NE) (e.g., the AMF 182) may indicate that the WTRU 102 is operating in MICO mode. At block 2520, the RE 180 may send the SR to the NE 182. At block 2530, the RE 180 may receive a message from the NE 182 including information that the WTRU 102 is operating in MICO mode. At block 2540, the RE 180 may store the information that the WTRU 102 is operating in MICO mode in a context of the WTRU 102. At block 2550, the RE 180 may stop triggering a change to an RRC inactivity state for the WTRU 102 based on the information stored in the context of the WTRU 102.

[0190] Although only two AMFs 182a and 182b are shown, any number of AMFs may be implemented in CN 115.

[0191] Various NEs and REs are illustrated herein, which may include one or more processors, one or more transmitters and one or more receivers, and one or more memories, and may be configured to operatively communicate and perform the methods of any of the embodiments disclosed herein.

[0192] A WTRU is presented herein that may include one or more processors, one or more transmitters and one or more receivers, and one or more memories, operatively communicating with and configured to perform the methods of any of the embodiments disclosed herein.

[0193] Although features and elements are described above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with the other features and elements. Furthermore, the methods described herein can be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of non-transitory computer-readable storage media include, but are not limited to, read-only memory (ROM), random-access memory (RAM), registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor associated with software can be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

[0194] Furthermore, in the above-described embodiments, processing platforms, computing systems, controllers, and other devices including processors are described. These devices may include at least one central processing unit ("CPU") and memory. According to the practices of those skilled in the art of computer programming, the acts and symbolic representations of operations or instructions may be performed by various CPUs and memories. Such acts and operations, or instructions, may be referred to as being "executed," "computer-executed," or "CPU-executed."

[0195] Those skilled in the art will understand that acts and symbolically represented operations or instructions include the manipulation of electrical signals by a CPU. The electrical system represents data bits that can cause transformations and reductions of electrical signals and that can cause the data bits to be maintained in storage locations within a memory system, thereby reconfiguring or otherwise altering the operation of the CPU and other signal processing. The storage locations where the data bits are maintained are physical locations that have specific electrical, magnetic, optical, or organic properties that correspond to or represent the data bits. It should be understood that the exemplary embodiments are not limited to the aforementioned platforms or CPUs, and that other platforms and CPUs can support the provided methods.

[0196] The data bits may also be maintained on computer-readable media, 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 a CPU. The computer-readable media may include cooperating or interconnected computer-readable media that resides dedicatedly on a processing system or that is distributed among multiple interconnected processing systems that may be local or remote to the processing system. It will be understood that exemplary embodiments are not limited to the aforementioned memories, and that other platforms and memories may support the described methods.

[0197] In the illustrated embodiment, any of the operations, processes, etc. described herein may be implemented as computer-readable instructions stored on a computer-readable medium. The computer-readable instructions may be executed by a processor of a mobile unit, a network element, and / or any other computing device.

[0198] There is little distinction between hardware and software implementations of aspects of the system. The use of hardware or software is generally a design choice representing a trade-off of efficiency versus cost (although in some contexts the choice between hardware and software can be important, but not always). There may be various means by which the processes and / or systems and / or other techniques described herein may be implemented (e.g., hardware, software, and / or firmware), and the preferred means may vary with the context in which the processes and / or systems and / or other techniques are deployed. For example, if an implementer determines that speed and accuracy are important, the implementer may select a primarily hardware and / or firmware implementation. If flexibility is important, the implementer may choose a primarily software implementation. Alternatively, the implementer may choose some combination of hardware, software, and / or firmware.

[0199] The foregoing detailed description has set forth various embodiments of devices and / or processes through the use of block diagrams, flow diagrams, and / or examples. To the extent that such block diagrams, flow diagrams, and / or examples include one or more functions and / or operations, those skilled in the art will understand that each function and / or operation included in such block diagrams, flow diagrams, or examples can be implemented individually and / or collectively by a wide range of hardware, software, firmware, or substantially any combination thereof. Suitable processors include, by way of example, general-purpose processors, special-purpose processors, conventional processors, digital signal processors (DSPs), multiple microprocessors, one or more microprocessors associated with a DSP core, controllers, microcontrollers, application-specific integrated circuits (ASICs), application-specific standard products (ASSPs), field-programmable gate array (FPGA) circuits, any other type of integrated circuit (IC), and / or state machines.

[0200] Although features and elements are provided above in particular combinations, those skilled in the art will understand that each feature or element can be used alone or in any combination with the other features and elements. The present disclosure is not limited by the specific embodiments described in this application, which are intended to illustrate various aspects. As will be understood by those skilled in the art, many modifications and variations can be made without departing from its spirit and scope. Unless expressly provided as such, no element, act, or instruction used in the description of this application should be construed as critical or essential to the invention. Functionally equivalent methods and apparatuses within the scope of the present disclosure, in addition to those enumerated herein, will be apparent to those skilled in the art from the foregoing description. Such modifications and variations are intended to be encompassed by the appended claims. The present disclosure is to be limited only by the appended claims, along with the full scope of equivalent forms to which such claims are entitled. It is understood that the present disclosure is not limited to any particular method or system.

[0201] It should also 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 "user equipment" and its abbreviation "UE" when referenced herein can mean (i) a wireless transmit / receive unit (WTRU), such as those described below, (ii) any of several embodiments of a WTRU, such as those described below, (iii) a wireless-enabled and / or wired-enabled (connectable) device configured with, among other things, some or all of the structure and functionality of a WTRU, such as those described below, (iv) a wireless-enabled and / or wired-enabled device configured with less than all of the structure and functionality of a WTRU, such as those described below, or (v) the like. Details of an exemplary WTRU, which can represent any UE described herein, are provided below with respect to Figures 1-5.

[0202] In some representative embodiments, portions of the subject matter described herein may be implemented in an application-specific integrated circuit (ASIC), field programmable gate array (FPGA), digital signal processor (DSP), and / or other integrated format. However, those skilled in the art will recognize that some aspects of the embodiments disclosed herein may equivalently be implemented in whole or in part 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 substantially any combination thereof, and that designing circuitry and / or writing code for software and / or firmware should be well within the skill of those skilled in the art in view of this disclosure. Furthermore, those skilled in the art will understand that the mechanisms of the subject matter described herein may be distributed as program products in various forms, and that exemplary embodiments of the subject matter described herein apply regardless of the particular type of signal-bearing medium used to actually effect the distribution. Examples of signal bearing media include, but are not limited to, recordable type media such as floppy disks, hard disk drives, CDs, DVDs, digital tape, computer memory, and transmission type media such as digital and / or analog communications media (e.g., fiber optic cables, wave guides, wired communications links, wireless communications links, etc.).

[0203] The subject matter described herein may depict different components contained within or connected to different other components. It should be understood that such depicted architectures are merely examples, and that in fact, many other architectures that achieve the same functionality may be implemented. In a conceptual sense, any configuration of components to achieve the same functionality is operatively “associated” to achieve the desired functionality. Thus, any two components combined herein to achieve a particular function can be seen to be “associated” with each other such that the desired functionality is achieved, regardless of the architecture or intermediate components. Similarly, any two components so associated can also be viewed as “operably connected” or “operably coupled” to each other to achieve the desired functionality, and any two components that can be so associated can also be viewed as “operably couplable” to each other to achieve the desired functionality. Specific examples of operably couplable include, but are not limited to, physically matable and / or physically interacting components, wirelessly interacting and / or wirelessly interacting components, and / or logically interacting and / or logically interacting components.

[0204] With respect to the use of virtually any plural and / or singular term herein, those of skill in the art will be able to convert from plural to singular and / or from singular to plural as appropriate to the context and / or application. Various singular / plural conversions may be expressly noted herein for clarity.

[0205] Those skilled in the art will understand that the terms used herein generally, and in the appended claims in particular (e.g., the body 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 "including but not limited to," and so forth). Those skilled in the art will further understand that where a specific number recited in an introduced claim is intended, such intention will be expressly recited in the claim; in the absence of such recitation, no such intention exists. For example, where only one item is intended, the term "single" or similar language may be used. To aid in understanding, the following appended claims and / or the description herein may include the use of the introductory phrases "at least one" and "one or more" to guide the recitation of the claims. However, the use of such phrases should not be construed as suggesting that introducing a claim recitation with the indefinite article "a" or "an" limits any particular claim containing a claim recitation so introduced to embodiments containing only one such recitation, even if the same claim also includes the introductory phrase "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should be construed to mean "at least one" or "one or more"). The same is true for the use of definite articles used to introduce claim recitations. Furthermore, even if a specific number of introduced claim recitations is explicitly recited, those skilled in the art will recognize that such recitation should be construed to mean at least the recited number (e.g., the recitation of "two recitations" alone, without any other modifier, means at least two recitations, or more than two recitations).Furthermore, in instances where language similar to "such as at least one of A, B, and C" is used, generally such a configuration is intended in the sense that one of ordinary skill in the art would understand the language (e.g., "a system having at least one of A, B, and C" would include, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). In instances where language similar to "such as at least one of A, B, or C" is used, generally such a configuration is intended in the sense that one of ordinary skill in the art would understand the language (e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems having only A, only B, only C, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). Those skilled in the art will further appreciate that virtually any disjunctive word and / or phrase in which two or more alternative terms are presented, whether in the description, claims, or drawings, should be understood to contemplate the possibility 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." Furthermore, as used herein, the term "any of," followed by a list of items and / or categories of items, is intended to include "any of," "any combination of," "any plurality of," and / or "any combination of," of the items and / or categories of items, individually or with other items and / or items from other categories. Furthermore, as used herein, the terms "set" or "group" are intended to include any number of items, including zero. Additionally, as used herein, the term "number" is intended to include any number, including zero.

[0206] Additionally, when features or aspects of the present disclosure are described in terms of a Markush group, those skilled in the art will recognize that the present disclosure is also thereby described in terms of any individual member or subgroup of members of the Markush group.

[0207] As will be understood by those skilled in the art, for any and all purposes, including with respect to providing a written description, all ranges disclosed herein also encompass any and all possible subranges and combinations of those subranges. Any recited range can be readily understood as fully descriptive and allowing for the same range to be broken down into at least equal halves, three, four, five, ten, etc. As a non-limiting example, each range discussed herein can be readily broken down into a lower third, a middle third, an upper third, etc. As will be further understood by those skilled in the art, all terms such as "up to," "at least," "greater than," "less than," and the like, refer to ranges that are inclusive of the recited numbers and that can then be broken down into the subranges discussed above. Finally, as will be understood by those skilled in the art, a range includes each individual member. Thus, for example, a group having 1 to 3 cells refers to groups having 1, 2, or 3 cells. Similarly, a group having 1 to 5 cells refers to groups having 1, 2, 3, 4, or 5 cells, and so on.

[0208] Furthermore, the claims should not be read as limited to the order or elements provided unless stated to that effect. In addition, the use of the term "means for" in any claim is intended to implement 35 U.S.C. 112, sixth paragraph, or means-plus-function claim format, and no claim not including the term "means for" is so intended.

[0209] A processor associated with software may be used to implement a radio frequency transceiver for use in a wireless transmit / receive unit (WTRU), user equipment (UE), terminal, base station, mobility management unit (MME) or evolved packet core (EPC), or any host computer. The WTRU may be used with modules implemented in hardware and / or software, including software-defined radios (SDRs), and other components such as cameras, video camera modules, video phones, speakerphones, vibration devices, speakers, microphones, television transceivers, hands-free headsets, keyboards, Bluetooth modules, frequency modulation (FM) radio units, near-field communications (NFC) modules, liquid crystal display (LCD) display units, organic light-emitting diode (OLED) display units, digital music players, media players, video game player modules, internet browsers, and / or any wireless local area network (WLAN) or ultra-wideband (UWB) modules.

[0210] Although the present invention is described in terms of a communications system, it is contemplated that the system may be implemented in software on a microprocessor / general purpose computer (not shown). In some embodiments, one or more of the functions of the various components may be implemented in software controlling a general purpose computer.

[0211] Additionally, while the invention is shown and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown, but rather, various changes may be made in the details within the scope and range of equivalent forms of the claims without departing from the invention. [Industrial Applicability]

[0212] The present invention can be used in wireless communication.

Claims

1. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: performing a first registration with a network entity (NE), the WTRU indicating that the WTRU is operating in a mobile initiated communications only (MICO) mode; determining whether the WTRU is registered in an "all PLMN" registration area; and, when the WTRU operating in MICO mode is not registered in the "all PLMN" registration area, determining whether the WTRU is outside the registration area associated with the first registration based on either (1) location-related information associated with the WTRU received after the first registration of the WTRU, or (2) a flag provided by the network. sending, by the WTRU, a service request (SR); performing a second registration or registration update prior to the SR on the condition that the WTRU is determined to be outside the registration area; A method for providing

2. and obtaining, by the WTRU, information indicating that the WTRU will initiate the second registration or the registration update prior to the sending of the SR. The method of claim 1 , wherein the step of performing the second registration or the registration update includes sending a registration request according to the obtained information.

3. The method of claim 1 or 2, wherein the step of obtaining the information for initiating the second registration or the registration update comprises obtaining the information by pre-configuration or by network signaling.

4. determining that the WTRU is registered in an "all PLMN" registration area; determining whether an "always registered" indication is set, provided that the WTRU is registered in the "all PLMN" registration area; sending a registration request to perform the second registration before the SR under the condition that an "always register" indication is set; The method of any of claims 1 to 3, further comprising:

5. obtaining a Tracking Area (TA) identifier of the WTRU's TA indicated in the broadcast signal; 5. A method according to claim 1, wherein the step of determining whether the WTRU is outside the registration area is based on whether the acquired TA identifier matches a stored TA identifier associated with the NE that last served the WTRU, and therefore the step of performing the second registration or the registration update is based on the condition that the acquired TA identifier does not match the stored TA.

6. obtaining an identifier associated with a registration area of ​​the WTRU indicated in a broadcast signal; 6. A method according to claim 1, wherein the step of determining whether the WTRU is outside the registration area is based on whether the acquired identifier matches a stored identifier associated with the NE that last served the WTRU, and the step of performing the second registration or the registration update is therefore based on the condition that the acquired identifier does not match the stored identifier.

7. 7. The method of claim 6, wherein the identifier is one of: (1) a tracking area identifier; or (2) an AMF identifier.

8. 8. The method of claim 5 or 7, wherein the SR is sent without any second registration or registration update before sending the SR, provided that the obtained TA identifier matches the stored TA identifier.

9. 1. A method performed by a WTRU operating in a mobile initiated communications only (MICO) mode and registered in a first registration area, comprising: determining whether the WTRU is outside the first registration area based on either (1) location-related information associated with the WTRU received after the registration of the WTRU, or (2) a network-provided flag; performing a registration update upon determining that the WTRU is outside the registration area; sending, by the WTRU, a service request (SR) after the registration update; A method for providing

10. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: performing a first registration with a network entity (NE), the WTRU indicating that the WTRU is operating in a mobile initiated communications only (MICO) mode; determining whether the WTRU is registered in an "all PLMN" registration area; selectively performing a second registration or registration update before sending a service request (SR) based on the WTRU not being registered in an "all PLMN" registration area and the WTRU being outside a registration area associated with the first registration; sending, by the WTRU, the SR; A method for providing

11. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: sending, by the WTRU, a service request (SR) including WTRU-specific information, the WTRU-specific information including: (1) an indication that the WTRU is operating in MICO mode; and (2) a temporary user identifier (TUID) of the WTRU; receiving, by the WTRU, a connection reconfiguration message and a WTRU configuration message including a new TUID that is different from the TUID in the SR; A method for providing

12. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: receiving, by the WTRU, a broadcast signal indicating a network entity (NE) identifier associated with a NE currently serving the WTRU; receiving a connection request from an upper layer; determining, by a second layer, whether the WTRU is operating in a mobile initiated communications only (MICO) mode; determining, by the WTRU, if the received NE identifier matches a stored NE identifier associated with the NE that last served the WTRU, provided that the WTRU is operating in MICO mode; sending a service request (SR) including WTRU-specific information, provided that the received NE identifier matches the stored NE identifier; A method for providing

13. 13. The method of claim 12, further comprising the step of sending a new registration or a registration update before sending an SR on the condition that the received NE identifier does not match the stored NE identifier.

14. 1. A method implemented by a wireless transmit / receive unit (WTRU), comprising: obtaining, by the WTRU, information indicating that the WTRU will initiate registration before sending a service request (SR); sending a registration request according to the obtained information; sending said SR after registering with a network entity (NE); A method for providing

15. 15. The method of claim 14, wherein the step of obtaining the information can include obtaining the information by pre-configuration or by network signaling.

16. determining whether the WTRU is operating in a mobile initiated communications only (MICO) mode; sending the registration request before the SR, provided that the WTRU is operating in the mobile initiated communication only (MICO) mode; 16. The method of claim 14 or 15, further comprising:

17. determining whether the WTRU is registered in an "all PLMN" registration area; sending the registration request before the SR, provided that the WTRU is registered in an "all PLMN" registration area; 17. The method of any of claims 14 to 16, further comprising:

18. receiving, by the WTRU, a broadcast signal indicating a Tracking Area (TA) identifier of a TA of the WTRU; receiving a connection request from an upper layer; determining, by a second layer, whether the WTRU is operating in a mobile initiated communications only (MICO) mode; determining, by the WTRU, whether the indicated TA identifier matches at least a stored TA identifier associated with a network entity (NE) that last served the WTRU, provided that the WTRU is operating in MICO mode; sending the SR on the condition that the indicated TA identifier matches the stored TA identifier; 18. The method of any of claims 14 to 17, further comprising:

19. 20. The method of claim 18, further comprising the step of sending a new registration or registration update before sending an SR on the condition that the indicated TA identifier does not match the stored TA identifier.

20. 1. A method implemented by a wireless transmit / receive unit (WTRU) in a mobile initiated communications only (MICO) mode, comprising: receiving, by the WTRU, a detach from a network entity (NE); determining, by the WTRU, whether to accept a disconnect; On condition that the WTRU accepts the detachment, (1) sending a detach complete by the WTRU, and (2) entering an idle mode by the WTRU; and (2) remaining in a connected mode by the WTRU; and, if the WTRU does not accept the detachment, (1) sending, by the WTRU, a detachment rejection with a cause code indicating that the WTRU is operating in the MICO mode. A method for providing

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