WO2017213687A1

WO2017213687A1 - Power saving states and paging mechanism in tsl (fifth generation (5g) new radio (nr) things (t) sidelink (sl)) communication

Info

Publication number: WO2017213687A1
Application number: PCT/US2016/062056
Authority: WO
Inventors: Satish C. Jha; Qian Li; Yaser M. FOUAD; Guangjie Li; Xiaoyun May Wu; Geng Wu
Original assignee: Intel Corporation
Priority date: 2016-06-08
Filing date: 2016-11-15
Publication date: 2017-12-14
Also published as: DE112016006956T5

Abstract

Techniques for implementing power saving states and paging techniques in connection with tSL (5G (Fifth Generation) NR (New Radio) Things SL (Sidelink)) communications are discussed. The power saving states can include a tSL-RRC (Radio Resource Control)-Active State that can facilitate data activity and monitor DL (downlink) channels and a paging channel, a tSL-RRC-Idle State with reduced power consumption that can still monitor the paging channel, and a tSL-RRC-Deep-PSM (Power Saving Mode) State that can provide further reduced power consumption. Further techniques are provided to facilitate tSL paging communications in connection with a tSL air interface.

Description

POWER SAVING STATES AND PAGING MECHANISM IN TSL (FIFTH GENERATION (5G) NEW RADIO (NR) THINGS (T) SIDELINK (SL)) COMMUNICATION

REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application No.

62/347,481 filed June 8, 201 6, entitled "POWER SAVING STATES AND PAGING MECHANISM IN 5G-WEARABLE COMMUNICATION", the contents of which are herein incorporated by reference in their entirety.

FIELD

[0002] The present disclosure relates to wireless technology, and more specifically to power saving states at tUEs (5G (Fifth Generation) NR (New Radio) Things (t) User Equipments (UEs)) and to a paging mechanism employable in connection with tSL (5G NR Things Sidelink (SL)) communications.

BACKGROUND

[0003] In conventional LTE (Long Term Evolution) systems, a User Equipment (UE) can be in a RRC (Radio Resource Control) Connected state or in a RRC Idle state. A UE can be in the RRC Connected state when an RRC Connection has been established with the E-UTRAN (Evolved Universal Terrestrial Radio Access Network), and in the RRC Connected state the UE can monitor a paging channel and control channels. A UE can be in the RRC Idle state when an RRC Connection has not been established with the E-UTRAN, and in the RRC Idle state the UE can monitor a paging channel but not control channels.

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a block diagram illustrating an example user equipment (UE) useable in connection with various aspects described herein.

[0005] FIG. 2 is an example diagram of a communication system that can facilitate tSL (5G (Fifth Generation) NR (New Radio) Things (t) Sidelink (SL)) communications according to various aspects described herein.

[0006] FIG. 3 is a diagram illustrating three radio states that can be employed at a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)), along with features of those radio states and transitions between those radio states, according to various aspects described herein. [0007] FIG. 4 is a diagram illustrating an example of periodic paging opportunities according to various aspects described herein.

[0008] FIG. 5 is a diagram illustrating example paging message structures according to various aspects described herein.

[0009] FIG. 6 is a block diagram illustrating a system that facilitates multiple power saving states as well as a tSL paging mechanism at a UE (e.g., network UE (nUE) or 5G NR Things UE (tUE)) in connection with a tSL (5G NR Things SL (Sidelink)), according to various aspects described herein.

[0010] FIG. 7 is a flow diagram illustrating a method that facilitates generation and transmission of a tSL paging message, according to various aspects described herein.

[0011] FIG. 8 is a flow diagram illustrating a method that facilitates reception and processing of a tSL paging message by a tUE according to various aspects described herein.

DETAILED DESCRIPTION

[0012] The present disclosure will now be described with reference to the attached drawing figures, wherein like reference numerals are used to refer to like elements throughout, and wherein the illustrated structures and devices are not necessarily drawn to scale. As utilized herein, terms "component," "system," "interface," and the like are intended to refer to a computer-related entity, hardware, software (e.g., in execution), and/or firmware. For example, a component can be a processor (e.g., a microprocessor, a controller, or other processing device), a process running on a processor, a controller, an object, an executable, a program, a storage device, a computer, a tablet PC and/or a user equipment (e.g., mobile phone, etc.) with a processing device. By way of illustration, an application running on a server and the server can also be a component. One or more components can reside within a process, and a component can be localized on one computer and/or distributed between two or more computers. A set of elements or a set of other components can be described herein, in which the term "set" can be interpreted as "one or more."

[0013] Further, these components can execute from various computer readable storage media having various data structures stored thereon such as with a module, for example. The components can communicate via local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from one component interacting with another component in a local system, distributed system, and/or across a network, such as, the Internet, a local area network, a wide area network, or similar network with other systems via the signal).

[0014] As another example, a component can be an apparatus with specific functionality provided by mechanical parts operated by electric or electronic circuitry, in which the electric or electronic circuitry can be operated by a software application or a firmware application executed by one or more processors. The one or more processors can be internal or external to the apparatus and can execute at least a part of the software or firmware application. As yet another example, a component can be an apparatus that provides specific functionality through electronic components without mechanical parts; the electronic components can include one or more processors therein to execute software and/or firmware that confer(s), at least in part, the functionality of the electronic components.

[0015] Use of the word exemplary is intended to present concepts in a concrete fashion. As used in this application, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". That is, unless specified otherwise, or clear from context, "X employs A or B" is intended to mean any of the natural inclusive permutations. That is, if X employs A; X employs B; or X employs both A and B, then "X employs A or B" is satisfied under any of the foregoing instances. In addition, the articles "a" and "an" as used in this application and the appended claims should generally be construed to mean "one or more" unless specified otherwise or clear from context to be directed to a singular form. Furthermore, to the extent that the terms "including", "includes", "having", "has", "with", or variants thereof are used in either the detailed description and the claims, such terms are intended to be inclusive in a manner similar to the term

"comprising."

[0016] As used herein, the term "circuitry" may refer to, be part of, or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware.

[0017] Embodiments described herein may be implemented into a system using any suitably configured hardware and/or software. FIG. 1 illustrates, for one embodiment, example components of a User Equipment (UE) device 100. In some embodiments, the UE device 100 may include application circuitry 102, baseband circuitry 104, Radio Frequency (RF) circuitry 106, front-end module (FEM) circuitry 108 and one or more antennas 1 10, coupled together at least as shown.

[0018] The application circuitry 102 may include one or more application processors. For example, the application circuitry 102 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processor(s) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0019] The baseband circuitry 104 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 104 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 106 and to generate baseband signals for a transmit signal path of the RF circuitry 106. Baseband processing circuity 104 may interface with the application circuitry 102 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 106. For example, in some embodiments, the baseband circuitry 104 may include a second generation (2G) baseband processor 104a, third generation (3G) baseband processor 104b, fourth generation (4G) baseband processor 104c, fifth generation (5G) baseband processor 104d (e.g., a 5G NR (New Radio) Things baseband processor, etc.), and/or other baseband processor(s) 104e for other existing generations, generations in development or to be developed in the future (e.g., one or more additional fifth generation (5G) baseband processors, 6G, etc.). The baseband circuitry 104 (e.g., one or more of baseband processors 104a-e) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 106. The radio control functions may include, but are not limited to, signal modulation/demodulation, encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 1 04 may include Fast-Fourier Transform (FFT), precoding, and/or constellation

mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 104 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality.

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

[0020] In some embodiments, the baseband circuitry 104 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 104e of the baseband circuitry 104 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 104f. The audio DSP(s) 104f may be include elements for compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 104 and the application circuitry 102 may be implemented together such as, for example, on a system on a chip (SOC).

[0021] In some embodiments, the baseband circuitry 104 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 104 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 104 is configured to support radio communications of more than one wireless protocol may be referred to as multi-mode baseband circuitry.

[0022] RF circuitry 106 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 106 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 106 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 108 and provide baseband signals to the baseband circuitry 104. RF circuitry 106 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 1 04 and provide RF output signals to the FEM circuitry 108 for transmission. [0023] In some embodiments, the RF circuitry 106 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 106 may include mixer circuitry 1 06a, amplifier circuitry 106b and filter circuitry 106c. The transmit signal path of the RF circuitry 106 may include filter circuitry 106c and mixer circuitry 106a. RF circuitry 106 may also include synthesizer circuitry 106d for synthesizing a frequency for use by the mixer circuitry 106a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 106a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 108 based on the synthesized frequency provided by synthesizer circuitry 106d. The amplifier circuitry 106b may be configured to amplify the down-converted signals and the filter circuitry 106c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 104 for further processing. In some embodiments, the output baseband signals may be zero- frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 1 06a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect.

[0024] In some embodiments, the mixer circuitry 106a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 106d to generate RF output signals for the FEM circuitry 108. The baseband signals may be provided by the baseband circuitry 104 and may be filtered by filter circuitry 1 06c. The filter circuitry 1 06c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect.

[0025] In some embodiments, the mixer circuitry 106a of the receive signal path and the mixer circuitry 106a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 106a of the receive signal path and the mixer circuitry 106a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 1 06a of the receive signal path and the mixer circuitry 106a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 106a of the receive signal path and the mixer circuitry 106a of the transmit signal path may be configured for super-heterodyne operation. [0026] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 106 may include analog-to-digital converter (ADC) and digital-to-analog converter (DAC) circuitry and the baseband circuitry 104 may include a digital baseband interface to communicate with the RF circuitry 106.

[0027] In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the

embodiments is not limited in this respect.

[0028] In some embodiments, the synthesizer circuitry 106d may be a fractional-N synthesizer or a fractional N/N+1 synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 106d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider.

[0029] The synthesizer circuitry 106d may be configured to synthesize an output frequency for use by the mixer circuitry 106a of the RF circuitry 1 06 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 106d may be a fractional N/N+1 synthesizer.

[0030] In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 104 or the applications processor 1 02 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a look-up table based on a channel indicated by the applications processor 1 02.

[0031] Synthesizer circuitry 1 06d of the RF circuitry 106 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DPA). In some embodiments, the DMD may be configured to divide the input signal by either N or N+1 (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip- flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0032] In some embodiments, synthesizer circuitry 1 06d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fLO). In some embodiments, the RF circuitry 106 may include an IQ/polar converter.

[0033] FEM circuitry 108 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 1 10, amplify the received signals and provide the amplified versions of the received signals to the RF circuitry 106 for further processing. FEM circuitry 108 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 106 for transmission by one or more of the one or more antennas 1 1 0.

[0034] In some embodiments, the FEM circuitry 108 may include a TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 106). The transmit signal path of the FEM circuitry 108 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 106), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 1 1 0.

[0035] In some embodiments, the UE device 100 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.

[0036] Additionally, although the above example discussion of device 100 is in the context of a UE device (e.g., a tUE (Fifth Generation (5G) New Radio (NR) Things (t) User Equipment) or a nUE (network UE)), in various aspects, a similar device can be employed in connection with a base station (BS) such as an Evolved NodeB (eNB), etc.

[0037] In various aspects, techniques disclosed herein can employ a simplified higher layer design for communication between a tUE and a nUE, involving a single layer - referred to herein as tSL-HL (5G NR Things Sidelink (SL) Higher Layer (HL)) - between an upper layer (e.g., an IP (Internet Protocol) layer, an application layer, etc.) and PHY (the physical layer) for the user plane, or between a tRRC (5G NR Things Radio Resource Control (RRC)) layer and PHY for the control plane.

[0038] Referring to FIG. 2, illustrated is an example diagram of a communication system 200 that can facilitate tSL (5G (Fifth Generation) NR (New Radio) Things (t) Sidelink (SL)) communications according to various aspects described herein. In system 200, Things devices (e.g., wearable devices, etc.) can be supported over a 5G NR- Things interface referred to herein as Xu-s. The communication system of FIG. 2 shows the following network nodes and interfaces: (1 ) a nUE (network UE) with full sidelink and direct link protocol stacks (e.g., with full C/U (control/user)-plane functions), which can act as a master UE in a sidelink cell/PAN (personal area network); (2) three tUEs (Things UEs, e.g., wearable UEs), which have a full sidelink protocol stack and can have (or can omit) a standalone direct link protocol stack, and can act as a slave UE in the sidelink cell/PAN; (3) a sidelink cell/PAN comprising the nUE and associated tUEs, which can employ mutual authentication to form the PAN; (4) the Xu-d interface, the radio link interface between the nUE/tUE and the 5G infrastructure; (5) the Xu-s interface, the radio link interface between the nUE and a tUE or between two tUEs; (6) the 5G-RAN (5G Radio Access Network); and (7) the 5G Core Network (5G-CN).

[0039] Various embodiments discussed herein relate to the Xu-s interface shown in FIG. 2. In various situations, a tUE can communicate with the 5G-RAN via the nUE. Each nUE can have several tUEs associated with it which together form a PAN (which can also be referred to herein as a Sidelink Cell). In general, there can be a large number of nUEs in a geographical region, each with their own PANs, which can create a high density network scenario. The 5G-RAN (or E-UTRAN (Evolved Universal Terrestrial Radio Access Network)) can assign a common resource pool for 5G NR- Things Sidelink Communication. This resource pool can be shared among multiple PANs in a close geographical area and among tUEs within each PAN on a contention based resource access basis. Each nUE can have at least the following two higher layer protocol stacks: (a) one for the 5G NR-Things Sidelink (tSL) Communication interface between tUE and nUE and (b) one for the 5G NR-Things Directlink Communication interface between nUE and 5G-RAN. The Higher Layer protocol stack for the interface nUE-5G-RAN can be the LTE Uu stack or a LTE evolved 5G protocol stack. As used herein, higher layer protocol stack refers mainly to protocol layer(s) in between PHY (the physical layer, also referred to herein as lower layer) and IP (Internet Protocol)/Application layers (also referred to herein as upper layer) in user plane. For example, higher layer refer to MAC (Medium Access Control), RLC (Radio Link

Control), and PDCP (Packet Data Convergence Protocol) layers of a conventional LTE system.

[0040] A tUE can monitor downlink control channels frequently or continuously to see whether there is a downlink packet transmission scheduled for the tUE, as well as to see whether there is a grant for uplink transmission, etc. However, performing downlink channel monitoring frequently or continuously consumes device power. If a tUE keeps monitoring downlink control channels even if there is no data activity for long time, it can result in significant and unnecessary device power consumption. Various aspects discussed herein relate to power saving states that can be employed at a tUE, tUE behavior in these states, and transition criteria for transitioning between these states. Various embodiments can employ these states to improve device power saving in connection with a 5G Things (5G-T) communication system. Additionally, in aspects, mechanisms discussed herein can be employed by which an nUE can reach tUE(s) in power saving states in situations wherein downlink data is available for the tUE(s). For example, various example procedures and components specific to 5G-T

communications are discussed herein in connection with a design of a paging mechanism to reach tUEs in power saving state(s). The proposed paging mechanism for 5G things can be solely handled by the nUE without the involvement of the 5G-RAN (or E-UTRAN) and can be transparent to the 5G-RAN (or E-UTRAN).

[0041] In various embodiments, mechanisms and techniques discussed herein can be employed in connection with 5G NR Things Sidelink Communications. In aspects, design aspects for power saving states that can be employed by a tUE are discussed, along with tUE behavior(s) that can be defined for those power saving states.

Additionally, transition procedures and criteria to move a tUE among these states are are discussed, which can improve device power saving. In further aspects, mechanisms are discussed by which an nUE can reach a tUE in a power saving state in the event downlink data is available for the tUE. tSL-RRC Radio States

[0042] Referring to FIG. 3, illustrated are three radio states that can be employed at a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)), along with features of those radio states and transitions between those radio states, according to various aspects described herein (Additionally, a nUE (network UE) can also employ Active, Idle, and Deep-PSM states in connection with its Xu-s interface, which are discussed in greater detail below). In various embodiments, one or more of these power saving states can be employed at a tUE, along with associated tUE behavior in these states, and/or transition criteria among these states, which can improve device power saving in a tSL (5G NR Things SL (Sidelink)) communication system. Additionally, in aspects, mechanisms can be employed by which an nUE can reach tUE(s) in power saving states in case downlink data arrive for them. As shown in FIG. 3, in various embodiments, three radio states can be employed at a tUE: Active/Connected (also referred to as tSL-RRC (tSL-Radio Resource Control)-Active (or tSL-RRC-Connected), Idle (also referred to as tSL-RRC-ldle or tSL-RRC-ldle-PSM) and Deep Power Saving Mode (tSL-RRC-Deep-PSM, Deep-PSM, or tSL-Deep-PSM). Features of each of these states are discussed below.

[0043] The features of the tSL-RRC-Active State discussed herein include: (a) it can be the highest power consuming state of the three tUE radio states; (b) the nUE can maintain a tUE-Connection-Context; (c) the tUE can maintain the Connection Context;

(d) Each tUE can have a Temp (temporary) Id (identity); (e) the nUE and tUE can both know and/or maintain each other's Temp ID and MAC (medium access control) ID; (f) the tUE can frequently or always monitors tUE-specific and nUE-specific DL (downlink) control channels; and (g) the tUE and nUE can send and/or receive data only in the tSL- RRC Active state.

[0044] The features of the tSL-RRC-ldle State discussed herein include: (a) it can be a low power consuming state; (b) the nUE can keep the tUE-Connection-Context; (b) the tUE can have a Temp Id; (c) the tUE can maintain the Connection Context; (d) the tUE can sleep most of the time (e.g., wherein it does not monitor DL control channels);

(e) the tUE can periodically monitor the paging channel only (e.g., not other DL control channels); (f) the tUE can move to tSL-RRC-Active state only by performing random access to send and/or receive data; and (g) the tUE can be configured to move to the Deep-PSM state if no data activity (e.g., no paging notification and no UL (uplink) data arrival) happens for a time equal to an Idle-to-Deep-PSM Timer period (e.g., a timer that can be defined/configured to determine how long to remain in tSL-RRC-ldle without data activity before transitioning to tSL-RRC-Deep-PSM).

[0045] The features of the tSL-RRC-Deep-PSM State discussed herein include: (a) it can be the least power consuming state; (b) it can involve the tUE going to sleep (e.g., not monitoring DL control channels) for a specified period; (c) the nUE can release the tUE-Connection-Context (e.g., such as the tUE Temp Id); (d) paging is not monitored by the tUE, such that the nUE cannot reach the tUE; and (f) the tUE can go through initial discovery after the Deep-PSM period is over to re-associate itself with the nUE.

State Transitions

[0046] When there is data activity (e.g., DL or UL data transmission from/to the nUE via the Xu-s interface), a tUE can move to and remain in the Active State (e.g., tSL- RRC-Active).

[0047] Once the data activity ended, the tUE can start a Timer called 'Active-to-ldle- PSM' Timer (e.g., a timer that can be defined/configured to determine how long to remain in tSL-RRC-Active without data activity before transitioning to tSL-RRC-ldle, which can measure the time since the most recent data activity involving the tUE). Upon any new data activity, the tUE can restart the 'Active-to-ldle-PSM' Timer.

[0048] When the 'Active-to-ldle-PSM' Timer expires, the tUE can be moved to the Idle state (e.g., tSL-RRC-ldle) to save power. The nUE and tUE can exchange paging configuration before the tUE moves to Idle. If a UL packet arrives at the tUE or if the tUE is paged by the nUE indicating a DL packet arrival, the tUE can terminate the Idle state and move to the Active State by performing random access.

[0049] For some 5G NR-Things device (e.g., tUE) categories which can tolerate high latency or which has very infrequent data, the tUE device can be moved directly to the Deep-PSM state (e.g., tSL-RRC-Deep-PSM) after expiry of the 'Active-to-ldle-PSM' Timer. Moving to Deep-PSM state can be initiated by either the nUE or the tUE. In both cases, the nUE and the tUE can have previously negotiated and agreed on the length of the Deep-PSM period before the tUE moves to Deep-PSM mode. After the Deep-PSM period is over, the tUE can be configured to move back to the Active State by performing Discovery (re-association) and random access. Some devices can be configured to move to Idle State after Deep-PSM period is over. In some such aspects, the tUE can keep its context even during the Deep-PSM state, and can also receive paging configuration before moving to the Deep-PSM State.

[0050] In the Idle state (e.g., tSL-RRC-ldle), the tUE can monitor only a paging channel periodically, and can omit any monitoring of other DL control channels. For some 5G NR-Things device categories (which can tolerate high latency or which has very infrequent data), if there is no paging for a specified period given by an 'ldle-to- PSM' Timer (e.g., a timer that can be defined/configured to determine how long to remain in tSL-RRC-ldle without paging before transitioning to tSL-RRC-Deep-PSM), the tUE can be configured to move to Deep-PSM. Such devices can determine (e.g., via configuration/negotiation from/with the nUE) the Deep-PSM period as well as the paging configuration (e.g., via configuration from the nUE) before moving to the Idle State.

Paging Mechanism

[0051] A tUE in the Idle State can be reached by the nUE by sending a paging in case of downlink packet arrival for the tUE. The paging message can be carried from nUE to tUE on a paging channel. A periodic paging resource can be employed for the paging channel. Details that can be employed example embodiments in connection with paging periodicity and resource configurations are described below.

Paging Cycles and Paging Resource

[0052] tUEs can be of various categories, some of which can tolerate very short latency (e.g., a few tens of ms) while some can tolerate very long delay (e.g, several seconds). From a power saving point of view, a longer paging cycle/periodicity (e.g., as indicated via a paging cycle value (e.g., Tp_aging)) can provide greater power saving. However, shorter paging cycles can be used for delay intolerant tUEs, although this can cause relatively higher power consumption.

[0053] Therefore, a range of paging cycles can be employed so that the tSL-RRC layer can configure one of these values based on tUE latency tolerance.

[0054] A paging cycle can be configured per tUE. However, tSL-RRC can configure same paging cycle for a group of tUEs with similar latency tolerance. In some scenarios, an nUE can employ a single common paging cycle for all tUEs.

[0055] In various embodiments, the Paging Cycle (T_Pag_ing) Value can range from 10ms to several seconds (e.g., up to 1 0.24s or potentially more). For example, potential values for Tp_aging can comprise the set {10ms, 20ms, 30ms 40ms, 60ms, 80ms, 120ms, 160ms, 240ms, 320ms, 480ms, 640ms, 960ms, 1280ms, 1 920ms, 2560ms, 3840ms, 51 20ms, 7680ms, 10240ms}. In various aspects, a longer paging cycle than 10240 ms can be employed; although 10240ms is based on a current maximum subframe number in conventional LTE, in various aspects, a greater maximum subframe number can be employed (e.g., a greater number for 5G systems, etc.). Referring to FIG. 4, illustrated is a diagram showing an example of periodic paging opportunities according to various aspects described herein.

[0056] Since the smallest paging cycle can be 10ms, a periodic paging resource can be employed in each frame (e.g., wherein 1 frame can be 10ms in an example frame structure). One or more PRBs can be assigned in a subframe/TTI (transmission time interval) wherein each subframe can be 1 ms, of each frame for paging channel.

[0057] For example, some frequency resource (e.g., one or more PRBs (physical resource blocks), for example, the central 6 PRBs) in subframe number 0 of each frame can be assigned for paging.

[0058] These paging resources can be divided into several groups in frequency/code domains to serve multiple groups of tUEs expecting paging in a paging TTI.

[0059] Alternately, one or more of these paging resource groups in a paging TTI can be randomly selected by the nUE to reduce inter-nUE paging interference. Since multiple neighboring nUEs can be using the same resources for paging without coordination among them, selecting only a part of total paging resources in a random way can reduce inter-nUE paging interference.

[0060] In aspects, a paging message in a paging TTI can be sent only when at least one tUE has a paging notification pending. If a common part of a paging is to be sent, a paging message can be sent even when none of the tUEs has a paging notification pending.

[0061] The paging resources in a TTI unused by paging can be used for regular DL data transmission or discovery message transmission by nUE.

Paging Frame and Paging TTI/Opportunity Determination:

[0062] The Paging Frame can be determined by the paging cycle (Tp_aging) value in a pre-defined way. For example, the Paging Frame for a tUE with paging Cycle (Tp_aging), can be calculated as a System Frame Number for which (System Frame Number Mod

Tpaging ⁼⁼ 0).

[0063] Within a Paging Frame (e.g., wherein a Frame can have 10 subframes) one or more of the 10 subframes can be defined as Paging TTIs/Opportunities in a predefined way. For example, one or more paging TTIs for a tUE can be calculated based on the tUE's Temp ID or tUE's MAC ID. Alternately, a known subframe (e.g,

subframe#0, etc.) of the paging frame can be defined as paging TTI for all tUEs. In another embodiment, different subframes of a paging Frame can be defined as paging TTIs for different categories/groups of tUE devices.

[0064] Within a paging TTI, frequency resources (such as one or more PRBs) can be defined as paging resources. In one embodiment, a central frequency band (such as 1 to 6 central PRBs) can be designated as paging resource in the paging TTI. A tUE can know (or can calculate deterministically) the exact paging resource (out of the total paging resources in this TTI of all tUEs) in the paging TTI where paging message can come for this tUE. For example, the exact paging resource for a tUE (out of total paging resources in this TTI of all tUEs) can be calculated based on the tUE's Temp ID or tUE's MAC ID. In another embodiment, a tUE can monitor all paging resources (e.g., total paging resources in this TTI for all tUEs) for paging message(s).

Paging Message Structure and Paging Message Transmission/Reception:

[0065] In various aspects described herein, a paging message can have two parts - an initial Common Paging Field and a Paging Record Field. Referring to FIG. 5, illustrated is a diagram showing example paging message structures according to various aspects described herein.

[0066] Example fields that can be employed in a Common Paging Field include: (1 ) a flag indicating Type 1 or Type 2 Paging Record Field; (2) a flag indicating the nUE Xu-s interface is moving to Idle at the next 'nUE Xu-s interface moving to Idle Boundary' and after that only an nUE specific common Paging Cycle will be supported; (3) a flag indicating the nUE Xu-s interface has moved back to Active from Idle State and the tUE specific paging cycle can be used starting from the next 'nUE Xu-s interface moving to Idle Boundary'; and (4) a flag to say 'nUE Xu-s Out of Idle'.

[0067] In the Paging Record Field, there can be a field for each tUE being paged. The Paging Record Field can be of two types: (1 ) Type 1 , wherein there is a field for tUE temp id of each tUE being paged in this TTI on this particular paging resource or (2) Type 2, wherein there is a Bitmap where each bit represents a tUE configured to be paged (or not) in this TTI on this particular paging resource.

[0068] A Type 1 Paging Record Field can have 0 or more Temp tUE Id fields present, depending on 0 or more tUEs that have a DL packet arrival. Therefore, a Type 1 Paging Record Field can be of variable size and can depend on the number of tUEs need to be paged in this TTI on this particular resource. A Type 1 Paging Record Field can be useful in scenarios where tUEs expect less frequent downlink packets, so that fewer number of paging record fields can be employed in a paging message.

[0069] Alternatively, a Type 2 Paging Record Field can be employed. If tUEs expect frequent downlink traffic, more tUEs can be paged frequently. In this case, many Temp ID fields would be included in each paging message if a Type 1 Paging Record Field is used, which increases the paging message size and subsequently takes up more paging resources. A Type 2 Paging Record Field can be suitable for this case as it uses fewer bits per tUE in paging record field. In a Type 2 Paging Record Field, the paging record field is of a fixed size, for example, with a number of bits in the paging record field (N_P Bits) of 10 bits, etc. The N p Bits value can depend on the maximum number of tUEs mapped to be paged in any TTI on a specific paging resource. Each bit (bit location) can be mapped to a tUE. If a bit is set to 1 , the corresponding tUE can be paged in this Paging TTI, and if a bit is set to 0, the corresponding tUE is not paged in this Paging TTI (or vice versa, in other aspects). The mapping of a tUE to a specific bit location in the bitmap can be exchanged when tUE is in Active State. For an example tUE Id size of 10 bits, a Paging record of 10 bits can page only one tUE in Type 1 , while 10 tUEs can be paged with 10 bits of paging record in Type 2.

[0070] In some embodiments, both Type 1 and Type 2 Paging Record Field Types can be used in the same TTI on different paging resources. For example, a Type 1 Paging Record Field can be used for one category of tUEs on paging resource PRB n1 and a Type 2 Paging Record Field can be used for another category of tUEs on paging resource PRB n2 in the same TTI.

[0071] In the same or other embodiments, both Type 1 and Type 2 Paging Record Field Types can be used in the same paging message (referred to as "Type 3" in FIG. 4.) in a paging TTI. For example, a Type 1 Paging Record Field can be used for one category of tUEs (e.g., tUEs that are paged infrequently) and a Type 2 Paging Record Field can be used for another category of tUEs (e.g., tUEs that are paged frequently) in the same paging message in a paging TTI.

[0072] The Paging Frame, Paging TTI and the Paging resources in a paging TTI for a tUE can be known to the tUE and nUE or can be calculated by the tUE and nUE. The nUE can include a paging record for the tUE in the paging message transmitted on the paging resource in the paging TTI of the tUE. The tUE can monitor the paging message on the same resource in the same TTI.

[0073] The paging message can be scrambled with an nUE Temp ID or a paging Temp ID defined for each nUE. For example, a Paging Temp Id can be derived by the tUE based on the nUE Temp Id, or a Paging Temp Id can be broadcasted by the nUE which the tUEs can store while in the active State. Alternately, a Paging Temp ID can be sent to each tUE as a part of unicast paging configuration when the tUE is in the Active State.

[0074] Defining a paging Temp ID can provide the advantage that it can uniquely identify paging messages distinctly from other regular messages. Note that unused paging resources in a paging TTI can be used for regular data transmission. Handling Downlink Data Buffering for tUEs in Idle and PSM States:

[0075] For tUEs in Idle, the nUE can buffer DL packets for the tUE in Idle state. The nUE can notify the tUE via paging to return to the active state. Once tUE is in active state, the nUE can send the buffered DL packet(s) to tUE. If paging fails and the nUE marks the tUE unreachable, the buffered data for the tUE can be discarded from the buffer.

[0076] For tUEs in PSM, the nUE can buffer the DL packets for a tUE in PSM state until the tUE comes back from PSM mode. At least a partial connection context of a tUE in Deep PSM state can be kept at the nUE for this purpose. After the PSM period, the tUE can be configured to move back to Active State or Idle State. If the tUE moves to Idle State after PSM period, the nUE notify the tUE by paging to come back to the active state. Once the tUE is in the active state, the nUE can send the buffered DL packet(s) to the tUE. Alternatively, if the tUE moves to the Active State after PSM period, the nUE can send the buffered DL packet to the tUE.

Handling tUE paging When nUE Xu-s Interface Moves to Idle/PSM mode:

[0077] The Xu-s interface radio can be different than the Uu interface, and in that case the nUE's Uu interface Idle/PSM state can have little impact on Xu-s interface Idle/PSM states.

[0078] The nUE's Xu-s interface can avoid the Idle/PSM states, as a new tUE can come anytime.

[0079] If the nUE's Xu-s interface goes to Idle, it can do so in situations wherein all the associated tUEs are in Idle/PSM State. Otherwise, the nUE can first ask all active tUEs to move to Idle/PSM mode before the nUE moves to Idle.

[0080] When nUE Xu-s interface moves to Idle, if nUE is in Idle mode, it can cease supporting different paging cycles for different tUEs in order to maximize nUE's power saving. Additionally, it can define a nUE specific common paging cycle to wake up and send paging to tUEs.

[0081] Before the nUE moves to Idle, it can inform tUEs by broadcasting a notification in paging message a few times. The notification can be designed as a common field in the paging message, for example, 'nUE Xu-s interface moving to Idle'. After this notification starts, the nUE can wait for the next boundary called 'nUE Xu-s interface moving to Idle Boundary' to move to Idle.

[0082] The start time of the nUE Idle state (e.g., the next 'nUE Xu-s interface moving to Idle Boundary') can be determined in a pre-defined way such as the next earliest SFN for which (SFN mod N nUE idle == 0)- _nuE idle can be a parameter provided to tUEs as a part of paging configuration when tUEs are in active State that indicates .

[0083] The nUE can start sending of 'nUE Xu-s interface moving to Idle' notification in paging message at a 'nUE Xu-s interface moving to Idle Boundary' and then move to Idle at next 'nUE Xu-s interface moving to Idle Boundary'.

[0084] The common paging cycle to be used when nUE is in Idle can be transmitted to tUE(s) either in a broadcast message or in a unicast messages when tUEs are in Connected/Active state.

[0085] When the nUE gets DL data for one or more tUE(s), it can send paging notification(s) in the very first upcoming paging opportunity of these tUEs. Additionally, the nUE Xu-s interface can come out of Idle in such a situation. tUEs can implicitly know that nUE is out of Idle state if there is a paging for any tUEs. Alternatively, a 1 bit flag (e.g., 'nUE Xu-s Out of Idle') can be added in the common part of the paging message to explicitly indicate it.

[0086] Additionally, in some situations, the nUE Xu-s interface can move to PSM. For example, the nUE can go to PSM state when all of its tUEs are in the PSM state. In such a situation, the nUE can go to the PSM state for a period less than the minimum of the remaining PSM periods of all of its tUEs. The nUE can start sending paging to tUEs after coming back from PSM if any of the PSM tUEs are configured to move to Idle after their PSM period(s). tUE moving Out of Coverage while in Idle State:

[0087] It can happen that a tUE moves out of coverage of the nUE while in Idle state. The nUE should minimize or eliminate resources (such as paging resource, tUE Temp Id) wasted on these devices. Below, mechanisms to handle this issue are discussed.

[0088] If a tUE is to be paged, the nUE can send a paging message to the tUE at a deterministic paging time and resource (Frame/TTI/frequency resource).

[0089] If the tUE does not respond to the nUE by performing Random Access within a specified time (e.g., as specified via a paging retransmit timer, Tp_aging_Retransmit), nUE can retransmit the paging message. For paging retransmission, nUE can retransmit paging in the very first paging opportunity for that tUE right after expiry of the Tpaging_Retransmit Timer. The nUE can retransmit the paging in a similar manner a number of times specified via a counter (N_Max-Paging) indicating a maximum number of paging transmissions. [0090] In some aspects, if paging for a tUE fails N_Max-Paging times, the nUE can mark the tUE 'UNREACHABLE', can stop sending future paging and can delete that tUE's context.

[0091] In other aspects, if paging for a tUE fails N_Max-Paging times, nUE can mark the tUE 'UNREACHABLE' and can stop sending future paging, but nUE can keep the tUE's context for a known period after marking the tUE 'UNREACHABLE'. It is possible that tUE may not know that it has missed a paging message. The paging message can be lost due to interference/collision, in which case, the tUE can simply assume that there was no paging for it. To address this issue, in various aspects, the following solution can be employed. In the solution, each tUE can be expected to contact the nUE by Random access, if the tUE does not receive a paging message for a specified period of time specified by a timer indicating a maximum idle time without receiving paging (e.g., T_Max- idie-without-Paging)- If the tUE does not contact the nUE for a (e.g., T_Max-idie-without-Paging plus a margin time) period, the nUE can confirm the tUE to be out of coverage and/or reach. The nUE can then delete the tUE's context if it has not done so yet, and can free the Temp Id for another tUE.

[0092] After expiry of the T_Max-idie-without-Paging Timer at the tUE, the tUE contacts the nUE if it is in coverage. Otherwise, it can release the context and can mark itself as connection-lost. The tUE can perform initial discovery if a UL packet arrives or if it comes back into coverage.

Paging Configuration Exchange

[0093] Paging configuration can be sent to each tUE via a unicast control message when that tUE is in the Active State. nUE specific Paging parameters which are applicable to all tUEs associated with this nUE can be transmitted in a broadcast control message. These parameters can include (1 ) an nUE specific common paging cycle; (2) a parameter (e.g., N_PUE idle) which can be used to calculate 'nUE Xu-s interface moving to Idle Boundary'; (3) a Maximum number of Paging retransmission(s) (e.g., N_Max-Paging) ; (4) a Paging Retransmission Timer (e.g., Tp_aging Retransmit) ; and (5) a Maximum period of time after which a tUE needs to contact nUE if no Paging message has been received

Example Embodiments

[0094] Referring to FIG. 6, illustrated is a block diagram of a system 600 that can facilitate multiple power saving states as well as a tSL paging mechanism at a UE (e.g., network UE (nUE) or 5G NR Things UE (tUE)) in connection with a tSL (5G NR Things SL (Sidelink)), according to various aspects described herein. System 600 can include one or more processors 610 (e.g., one or more baseband processors such as one or more of the baseband processors discussed in connection with FIG. 1 ), transceiver circuitry 620 (e.g., comprising one or more of transmitter circuitry or receiver circuitry, which can employ common circuit elements, distinct circuit elements, or a combination thereof), and a memory 630 (which can comprise any of a variety of storage mediums and can store instructions and/or data associated with one or more of processor(s) 610 or transceiver circuitry 620). In various aspects, system 600 can be included within a user equipment (UE), either in a 5G NR Things UE (tUE, e.g., a wearable tUE, etc.) or in a network UE (nUE). As described in greater detail below, system 600 can provide functionality for tSL-RRC (Radio Resource Control) power saving states and a paging mechanism at a UE (e.g., tUE or nUE) in connection with tSL communications.

[0095] In a first set of embodiments, system 600 can be included within a tUE, wherein system 600 can provide functionality in connection with tSL-RRC power saving states and/or a tSL paging mechanism at the tUE. In a second set of embodiments, system 600 can be included within a nUE, wherein system 600 can provide functionality in connection with tSL-RRC power saving states and/or a tSL paging mechanism at the nUE.

[0096] In connection with power saving states of the first set of embodiments, processor(s) 610 can employ any of the tUE tSL-RRC States discussed herein: the tSL- RRC-Active State, the tSL-RRC-ldle State, or the tSL-RRC-Deep-PSM State. At any given point, processor(s) 61 0 can employ a single state among these tSL-RRC States.

[0097] When employing the tSL-RRC-Active state, processor(s) 610 can maintain a Connection Context with a nUE of a PAN (personal area network) associated with the tUE, maintain a temporary identity (Temp ID) associated for the tUE in connection with the nUE and PAN, and can maintain a nUE Temp ID and nUE MAC (Medium Access Control) ID associated with the nUE of the PAN. Also while in the tSL-RRC-Active State, processor(s) 610 can monitor (e.g., via signals received by transceiver circuitry 620 over a tSL air interface (e.g., the Xu-s interface)) one or more DL control channels (e.g., tUE- specific control channel(s) and nUE control channel(s)) from the nUE, as well as a tSL paging channel (e.g., for common paging messages) from the nUE. When employing the tSL-RRC-Active State, processor(s) 610 can send and/or receive data (e.g., UL (uplink) data and/or DL data) with the nUE via transceiver circuitry 620. In various aspects described herein, processor(s) 610 can only send and/or receive data with the nUE when employing the tSL-RRC Active State. Because processor(s) 610 can monitor multiple DL channels and potentially send and/or receive data via the tSL-RRC-Active State, power consumption in the tSL-RRC-State can be higher than in other tSL-RRC States.

[0098] When employing the tSL-RRC Idle State, processor(s) 610 can maintain the Connection Context and tUE Temp Id. Additionally, in the tSL-RRC-ldle State, processor(s) 610 can monitor the tSL paging channel via transceiver circuitry 620, but can omit monitoring of DL control channels, and can thereby save power compared to the tSL-RRC-Active State. To send and/or receive data, processor(s) 610 can transition to the tSL-RRC-Active State via performing random access.

[0099] In the tSL-RRC-Deep-PSM State, processor(s) 61 0 can omit monitoring of DL control channels and the tSL paging channel, thereby saving power relative to the other tSL-RRC States. Because the tSL paging channel is not monitored and thus the tUE is not in contact with the nUE, processor(s) 610 can employ the tSL-RRC-Deep-PSM State for a predetermined period of time that can be configured to the tUE or negotiated between the tUE and nUE via the tSL air interface (e.g., the Xu-s interface) by messaging received and/or sent via transceiver circuitry 620. In some aspects, processor(s) 610 can release the Connection Context (e.g., including Temp Id) when employing the tSL-RRC-Deep-PSM State. In other aspects, however, processor(s) 610 can maintain at least a portion of the Connection Context while in tSL-RRC-Deep-PSM, which can facilitate transition to the tSL-RRC-ldle State from the tSL-RRC-Deep-PSM State.

[00100] As described herein, based on various criteria, processor(s) 610 can transition from a current tSL-RRC State to a new tSL-RRC State.

[00101 ] For example, if processor(s) 610 is employing the tSL-RRC-Active State, processor(s) 610 can transition to the tSL-RRC-ldle State if a timer (e.g., 'Active-to-ldle- PSM') that measures the time since a most recent data activity (e.g., DL or UL) expires (or, in various aspects, in response to the nUE indicating the tUE to transition via tSL paging message). Prior to expiration of the timer, processor(s) 610 be configured by the nUE or negotiate with the nUE (via messaging received/sent by transceiver circuitry 620) on a paging cycle value for the tUE (e.g., individually, based on the device class of the tUE, or for all tUEs in the PAN) such that processor(s) 610 can monitor the tSL paging channel while employing the tSL-RRC-ldle State. As another example, in some aspects, if processor(s) 610 is employing the tSL-RRC-Active State, processor(s) 610 can transition directly to the tSL-RRC-Deep-PSM State upon expiration of the timer that measures the time since the most recent data activity (or, in various aspects, in response to the nUE indicating the tUE to transition via tSL paging message). In such aspects, prior to expiration of the timer, processor(s) 610 be configured by the nUE or negotiate with the nUE (via messaging received/sent by transceiver circuitry 620) on a duration of time for processor(s) 610 to employ the tSL-RRC-Deep-PSM state before transitioning to the tSL-RRC-Active State or the tSL-RRC-ldle State.

[00102] In another example, if processor(s) 610 are employing the tSL-RRC-ldle State and determine via the tSL paging channel that there is pending data activity for the tUE (e.g., pending DL data, etc.), processor(s) 610 can transition to the tSL-RRC-Active State via performing random access. As a further example, in some embodiments (e.g., implemented in certain tUE device categories, etc.), if processor(s) 610 are employing the tSL-RRC-ldle State and a second timer (e.g., a 'Idle-to-PSM' Timer) expires that can measure the time in tSL-RRC-ldle since the most recent paging for the tUE (wherein the second timer can also be configured/negotiated via messaging exchanged via transceiver circuitry 620), processor(s) can transition to the tSL-RRC-Deep-PSM State (or, in various aspects, processor(s) 610 can transition in response to the nUE indicating the tUE to transition via tSL paging message), and in some aspects can release the Connection Context, while in other aspects can maintain the Connection Context or a portion thereof. Prior to transitioning to the tSL-Deep-PSM State, processor(s) 610 can be configured for or negotiate with the nUE for (e.g., via messaging exchanged via transceiver circuitry 620) a duration of the tSL-RRC-Deep- PSM State.

[00103] As an additional example, if processor(s) 610 are employing the tSL-RRC- Deep-PSM State, which can have a duration associated with it, processor(s) 610 can transition to another tSL-RRC State after that duration expires. In some aspects, if processor(s) 610 have maintained at least a partial Connection Context, processor(s) 61 0 can transition to the tSL-RRC-ldle State based on a configured paging cycle, temp ID, etc. In other aspects, processor(s) 610 can transition from the tSL-RRC-Deep-PSM State to the tSL-RRC-Active State, via processor(s) 610 perform discovery and random access procedures.

[00104] In connection with the second set of embodiments, system 600 can be employed in a nUE in connection with tSL-RRC States of a tSL air interface at the nUE, which can also include Active, Idle, and Deep-PSM States that can be employed by processor(s) 610. [00105] In the nUE Active State, processor(s) 61 0 can generate (and transceiver circuitry 620 can transmit) tSL paging messages for tSL-RRC-Active/ldle tUEs having one or more paging cycle values (e.g., which processor(s) 610 can configure for individual tUEs, device classes of tUEs, and/or for all tUEs), which can indicate common paging fields (e.g., that the nUE is transitioning to a nUE Idle State, etc.) to tSL-RRC- Active/ldle tUEs, and can indicate to tSL-RRC-ldle tUE(s) whether processor(s) 610 has buffered DL data pending for the tSL-RRC-ldle tUE(s). Processor(s) 610 can exchange data with tUEs that are in tSL-RRC-Active State via processor(s) 610 scheduling DL/UL transmission(s) via a DL control channel and transceiver circuitry 620

transmitting/receiving the DL/UL transmission(s). As discussed herein, a tUE notified of pending data via the tSL paging channel can return to the tSL-RRC-Active State, at which time processor(s) 610 can commence data activity with that tUE. In some aspects, if DL data arrives for such a tUE in a tSL-RRC-Deep-PSM State, processor(s) 61 0 can buffer that DL data, and when that tUE returns to tSL-RRC-Active, processor(s) 61 0 can schedule and transceiver 620 can transmit that DL data. In other such aspects, processor(s) 610 can maintain at least a partial tUE Connection Context for a tUE in tSL-RRC-Deep-PSM, and upon that tUE returning to tSL-RRC-ldle, processor(s) 610 can generate (and transceiver circuitry 620 can transmit) tSL paging messaging indicating the buffered pending DL data for that tUE.

[00106] In the nUE Idle State, processor(s) 610 can generate (and transceiver circuitry 620 can transmit) tSL paging messages for tSL-RRC-ldle tUEs for a single common paging cycle value, which can save power. Processor(s) 610 can transition to the nUE Idle State if there are no tUEs in the tSL-RRC-Active State, and can indicate the transition via a tSL paging message generated by processor(s) 610 and transmitted by transceiver circuitry 620, which can indicate that the nUE is transitioning its tSL air interface (e.g., the Xu-s interface) to the Idle state at a next occasion among

preconfigured occasions. If DL data becomes pending for any of the tUEs (e.g., generated by processor(s) 610, received by transceiver circuitry 620 via an air interface, etc.), processor(s) 610 can processor(s) 610 can transition to the nUE Active State, and can indicate to the tUEs that it is transitioning to the nUE Active State (e.g., via a tSL paging message generated by processor(s) 610 and transmitted via transceiver circuitry 620), either explicitly or implicitly via indicating pending DL data for a tUE.

[00107] In the nUE Deep PSM State, processor(s) 610 can omit sending tSL paging messages, which can save power. Because of this, processor(s) 610 can avoid entering the nUE Deep PSM State unless all tUEs are in a tSL-RRC-Deep-PSM State, and can enter the nUE Deep PSM State for less than the minimum duration of the durations of the tUE tSL-RRC-Deep-PSM State(s).

[00108] Additional aspects of the first and second sets of embodiments of system 600 can relate to tSL paging messaging over a tSL paging channel.

[00109] In the second set of embodiments, processor(s) 610 can determine whether any tUEs in tSL-RRC-ldle State have pending DL data buffered by processor(s) 610. Processor(s) 610 can generate a tSL paging message comprising a common paging field and a paging record field. The common paging field can specify the type of paging record field, which can be of the types described herein, and can also indicate State changes of the tSL interface of the nUE (e.g., transitioning to Idle, returned to Active). Processor(s) 610 can indicate tUEs in a Type 1 paging record field via a Temp ID of the tUE(s) in tSL-RRC-ldle State that have pending DL data or in a Type 2 paging record field via a bitmap wherein each bit is associated to a distinct tUE of a set of tUEs comprising those tUEs (or a Type 3, combining a Type 1 portion and a Type 2 portion).

[00110] Processor(s) 610 can select a paging frame to schedule the tSL paging message based on the paging cycle value(s) of the tUE(s). In the selected paging frame, processor(s) 610 can schedule the tSL paging message in a periodic paging resource that can be dedicated for a tSL paging channel (e.g., a center n PRBs

(physical resource blocks) in subframe #0, such as a center 6 PRBs, etc.), or a portion thereof. In some aspects, the periodic paging resources can be divided into a plurality of code and/or frequency groups, and processor(s) 610 can select one or more of the groups for scheduling the tSL paging message in a random, etc. manner. Processor(s) 61 0 can pass the scheduled paging message to a tSL-PHY (physical layer) for transmission by transceiver circuitry 620.

[00111 ] For each tUE that has pending DL data that does not perform random access to return to tSL-RRC-Active State after transmission of the tSL paging message, processor(s) 610 can retransmit paging for that tUE a predetermined or configurable threshold number of times. If that tUE does not perform random access to return to tSL- RRC-Active after the threshold number of retransmissions, processor(s) 610 can release the tUE Connection Context of that tUE, which can mitigate unnecessary use of resources on tUEs that can be out of contact (if that tUE regains contact, that tUE can subsequently perform discovery and random access to obtain a new Connection Context).

[00112] In the first set of embodiments, a tSL paging message can be received via transceiver circuitry 620 if processor(s) 610 is employing either the tSL-RRC-Active State or the tSL-RRC-ldle State. Processor(s) 61 0 can determine the paging frame to receive the tSL paging message based on a paging cycle value configured for the tUE comprising system 600. Processor(s) 610 can process the received tSL paging message, which can comprise a common paging field and a paging record field. From the common paging field, processor(s) 610 can determine the type of paging record field, which can comprise zero or more tUE Temp IDs and/or a bitmap wherein each bit is associated with a distinct tUE. Additionally, based on the common paging field, processor(s) 610 can determine whether or not the nUE will transition to an Active State and/or to an Idle State.

[00113] Based on the paging record field, when processor(s) 610 is employing the tSL-RRC-ldle State, processor(s) 610 can determine whether there is DL data pending for the tUE comprising system 600 (e.g., via a Temp ID of that tUE in a Type 1 or Type 3 record field, or as indicated via an associated bit of a bitmap in a Type 2 or Type 3 record field).

[00114] If the paging record field indicates that there is pending DL data for the tUE comprising system 600, processor(s) 610 can perform a random access procedure and can transition to the tSL-RRC-ldle State. In the tSL-RRC-Active State, processor(s) 610 can exchange data with the nUE.

[00115] Referring to FIG. 7, illustrated is a flow diagram of a method 700 that facilitates generation and transmission of a tSL paging message, according to various aspects described herein. In some aspects, method 700 can be performed at a nUE. In other aspects, a machine readable medium can store instructions associated with method 700 that, when executed, can cause a nUE to perform the acts of method 700.

[00116] At 710, one or more tSL-RRC-ldle State tUEs can be determined for which DL data is pending in a buffer.

[00117] At 720, a tSL paging message can be generated comprising a common paging field and a paging record field, wherein the common paging field indicates the type of paging record field, and the paging record field indicates the one or more tSL- RRC-ldle State tUEs for which DL data is pending.

[00118] At 730, a paging frame can be determined for transmission of the tSL paging message based on paging cycle values of the tSL-RRC-ldle State tUE(s).

[00119] At 740, the tSL paging message can be transmitted via a periodic paging resource of the determined paging frame. [00120] Additionally or alternatively, method 700 can include one or more other acts performed by a system of the second set of embodiments as described above in connection with system 600.

[00121 ] Referring to FIG. 8, illustrated is a flow diagram of a method 800 that facilitates reception and processing of a tSL paging message by a tUE according to various aspects described herein. In some aspects, method 800 can be performed at a tUE. In other aspects, a machine readable medium can store instructions associated with method 800 that, when executed, can cause a tUE to perform the acts of method 800.

[00122] At 810, a paging frame can be determined based on a paging cycle value configured for the tUE employing method 800.

[00123] At 820, a tSL paging message can be received via a periodic paging resource of the determined paging frame, wherein the tSL paging message comprises a common paging field and a paging record field.

[00124] At 830, a type of the paging record field can be determined based on the common paging field.

[00125] At 840, based on the paging record field and determined type, a

determination can be made whether DL data is pending for the tUE employing method 800.

[00126] At 850, in response to a determination that DL data is pending, a random access procedure can be performed.

[00127] At 860, in response to a determination that DL data is pending, the tUE can be transitioned to a tSL-RRC-Active State to receive the pending DL data.

[00128] Additionally or alternatively, method 800 can include one or more other acts performed by a system of the first set of embodiments described above in connection with system 600.

[00129] Examples herein can include subject matter such as a method, means for performing acts or blocks of the method, at least one machine-readable medium including executable instructions that, when performed by a machine (e.g., a processor with memory, an application-specific integrated circuit (ASIC), a field programmable gate array (FPGA), or the like) cause the machine to perform acts of the method or of an apparatus or system for concurrent communication using multiple communication technologies according to embodiments and examples described.

[00130] Example 1 is an apparatus configured to be employed within a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)), comprising: a memory; and one or more processors configured to: employ a tSL (5G NR Things SL (Sidelink))-RRC (Radio Resource Control) State, wherein the tSL-RRC State is one of a tSL-RRC-Active State, a tSL-RRC-ldle State, or a tSL-Deep-PSM (Power Saving Mode) State; maintain a Connection Context with a nUE (network UE) and monitor a paging channel from the nUE when employing the tSL-RRC-Active State or the tSL-RRC-ldle State; and monitor one or more DL (downlink) channels from the nUE when employing the tSL-RRC-Active State, wherein the tSL-RRC- Active State is associated with greater power consumption than the tSL-RRC-ldle State, which is associated with greater power consumption than the tSL-RRC-Deep-PSM State.

[00131 ] Example 2 comprises the subject matter of any variation of any of example(s)

1 , wherein the tSL-RRC State is the tSL-RRC-Active State, and wherein the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC- Idle state in response to an expiration of a timer that measures time since a most recent data activity involving the tUE.

[00132] Example 3 comprises the subject matter of any variation of any of example(s)

2, wherein the one or more processors are further configured to determine a paging configuration prior to transitioning the tSL-RRC State to the tSL-RRC-ldle State, wherein the paging configuration is based on tSL messaging exchanged with the nUE.

[00133] Example 4 comprises the subject matter of any variation of any of example(s) 1 -3, wherein the tSL-RRC State is the tSL-RRC-Active State, and wherein the one or more processors are further configured to exchange data with the nUE via a tSL air interface.

[00134] Example 5 comprises the subject matter of any variation of any of example(s) 1 , wherein the tSL-RRC State is the tSL-RRC-Active State, and wherein the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC- Deep-PSM State in response to an expiration of a timer that measures the time since the most recent data activity involving the tUE.

[00135] Example 6 comprises the subject matter of any variation of any of example(s) 5, wherein the one or more processors are further configured to determine a duration of the tSL-RRC-Deep-PSM State prior to transitioning the tSL-RRC State to the tSL-RRC- Deep-PSM State, wherein the duration of the tSL-RRC-Deep-PSM State is based on tSL messaging exchanged with the nUE.

[00136] Example 7 comprises the subject matter of any variation of any of example(s) 1 , wherein the tSL-RRC State is the tSL-RRC-ldle State, and wherein the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-Deep- PSM State in response to an expiration of a timer that measures the time since the most recent paging involving the tUE.

[00137] Example 8 comprises the subject matter of any variation of any of example(s) 7, wherein the one or more processors are further configured to determine a duration of the tSL-RRC-Deep-PSM State prior to transitioning the tSL-RRC State to the tSL-RRC- Deep-PSM State, wherein the duration of the tSL-RRC-Deep-PSM State is based on tSL messaging exchanged with the nUE.

[00138] Example 9 comprises the subject matter of any variation of any of example(s) 1 , 7, or 8, wherein the tSL-RRC State is the tSL-RRC-ldle state, and wherein, in response to the monitored paging channel indicating data activity associated with the tUE, the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-Active State via performing random access.

[00139] Example 10 comprises the subject matter of any variation of any of example(s) 1 , wherein the tSL-RRC State is the tSL-RRC-Deep-PSM State, wherein the one or more processors are further configured to: release the Connection Context; and in response to the expiration of a duration of the tSL-RRC-Deep-PSM State, transition the tSL-RRC State to the tSL-RRC- Active State via performing discovery and random access.

[00140] Example 1 1 comprises the subject matter of any variation of any of example(s) 1 , wherein the tSL-RRC State is the tSL-RRC-Deep-PSM State, wherein the one or more processors are further configured to maintain the Connection Context and a paging configuration, and wherein, in in response to the expiration of a duration of the tSL-RRC- Deep- PSM State, the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-ldle State.

[00141 ] Example 12 comprises the subject matter of any variation of any of example(s) 1 , wherein the tSL-RRC State is the tSL-RRC-Active State, and wherein the one or more processors are further configured to: transition the tSL-RRC State to the tSL-RRC-ldle state in response to an expiration of a timer that measures time since a most recent data activity involving the tUE; and determine a paging configuration prior to transitioning the tSL-RRC State to the tSL-RRC-ldle State, wherein the paging configuration is based on tSL messaging exchanged with the nUE.

[00142] Example 13 comprises the subject matter of any variation of any of example(s) 1 , wherein the tSL-RRC State is the tSL-RRC-ldle State, and wherein the one or more processors are further configured to: transition the tSL-RRC State to the tSL-RRC-Deep-PSM State in response to an expiration of a timer that measures the time since the most recent paging involving the tUE; and determine a duration of the tSL-RRC-Deep-PSM State prior to transitioning the tSL-RRC State to the tSL-RRC- Deep-PSM State, wherein the duration of the tSL-RRC-Deep-PSM State is based on tSL messaging exchanged with the nUE.

[00143] Example 14 is an apparatus configured to be employed within a nUE (network UE (User Equipment)), comprising: a memory; and one or more processors configured to: maintain a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)) Connection Context for each tUE of a set of tUEs, wherein each tUE of the set of tUEs is in a tSL (5G NR Things SL (Sidelink))-RRC (Radio Resource Control)-Active State or a tSL-RRC-ldle State; determine, for each tUE of the set of tUEs, whether DL (downlink) data is pending for that tUE; and for each tUE for which DL data is pending: notify that tUE via a tSL paging channel message to return to the tSL-RRC-Active State when that tUE is in the tSL-RRC-ldle State; and schedule the DL data pending for that tUE for transmission via a DL control channel message when that tUE is in the tSL-RRC-Active State.

[00144] Example 15 comprises the subject matter of any variation of any of example(s) 14, wherein the one or more processors are further configured to: determine a paging configuration for a first tUE of the set of tUEs, wherein the first tUE is in the tSL-RRC-Active State; and generate tSL messaging that indicates the paging configuration for the first tUE prior to the first tUE transitioning to the tSL-RRC-ldle State.

[00145] Example 16 comprises the subject matter of any variation of any of example(s) 15, wherein the first tUE has a first device type, and wherein the tSL messaging indicates the paging configuration for each tUE of the set of tUEs that has the first device type.

[00146] Example 17 comprises the subject matter of any variation of any of example(s) 14, wherein each tUE of the set of tUEs is in the tSL-RRC-ldle State, and wherein the one or more processors are further configured to transition a tSL air interface of the nUE to an Idle state.

[00147] Example 18 comprises the subject matter of any variation of any of example(s) 17, wherein the tSL messaging indicates the paging configuration for each tUE of the set of tUEs.

[00148] Example 19 comprises the subject matter of any variation of any of example(s) 14-18, wherein the one or more processors are further configured to:

determine a Deep PSM (Power Saving Mode) duration for a second tUE of the set of tUEs; and generate tSL messaging that indicates the Deep PSM duration for the second tUE prior to the second tUE transitioning to a tSL-RRC-Deep-PSM State.

[00149] Example 20 comprises the subject matter of any variation of any of example(s) 19, wherein the second tUE is the only tUE of the set of tUEs in the tSL- RRC-Active State or in the tSL-RRC-ldle State, and wherein the one or more

processors are further configured to: determine a minimum remaining Deep PSM duration among a set of Deep PSM durations for tUEs, wherein the set of Deep PSM durations comprises the Deep PSM duration for the second tUE; and transition a tSL air interface of the nUE to a Deep PSM state for a time less than the minimum remaining Deep PSM duration.

[00150] Example 21 comprises the subject matter of any variation of any of example(s) 14-18, wherein the one or more processors are further configured to maintain at least a partial Connection Context for a third tUE in a tSL-RRC-Deep-PSM State.

[00151 ] Example 22 comprises the subject matter of any variation of any of example(s) 21 , wherein additional DL data is pending for the third tUE, and wherein the one or more processors are further configured to: buffer the additional DL data; if the third tUE transitions to the tSL-RRC-ldle State, notify the third tUE via an additional tSL paging channel message to return to the tSL-RRC-Active State; and schedule the additional DL data pending for the third tUE for transmission via an additional DL control channel message when the third tUE is in the tSL-RRC-Active State.

[00152] Example 23 is an apparatus configured to be employed within a nUE (network UE (User Equipment)), comprising: a memory; and one or more processors configured to: determine one or more tUEs (5G (Fifth Generation) NR (New Radio) Things UEs) for which DL (downlink) data is pending in a buffer; generate a tSL (5G NR Things SL (Sidelink)) paging message for the one or more tUEs, wherein the tSL paging message comprises a common paging field and a paging record field that indicates each of the one or more tUEs; determine a paging frame for the one or more tUEs based on a paging cycle value for the one or more tUEs; schedule the tSL paging message to at least a portion of a periodic paging resource associated with a tSL paging channel in the paging frame; and pass the tSL paging message to a tSL-PHY (Physical Layer) for communication via the periodic paging resource over a tSL air interface.

[00153] Example 24 comprises the subject matter of any variation of any of example(s) 23, wherein the paging record field indicates each of the one or more tUEs via a bitmap, wherein each tUE of the one or more tUEs is associated with a distinct bit of the bitmap, and wherein the common paging field indicates that the paging record field comprises the bitmap.

[00154] Example 25 comprises the subject matter of any variation of any of example(s) 23, wherein the paging record field indicates the one or more tUEs via one or more temporary identities associated with the one or more tUEs, and wherein the common paging field indicates that the paging record field comprises the one or more temporary identities.

[00155] Example 26 comprises the subject matter of any variation of any of example(s) 23-25, wherein the one or more processors are further configured to:

determine a number of paging retransmissions for each tUE of the one or more tUEs; and for each tUE of the one or more tUEs, release a Connection Context of that tUE when the number of paging retransmissions exceeds a threshold value.

[00156] Example 27 comprises the subject matter of any variation of any of example(s) 23-25, wherein the one or more processors are further configured to:

determine a number of paging retransmissions for each tUE of the one or more tUEs; for each tUE of the one or more tUEs, when the number of paging retransmissions exceeds a threshold value, determine whether that tUE attempts random access within a time period after the most recent paging retransmission, wherein the time period is based on a timer indicating a maximum idle time without receiving paging plus a margin time; and for each tUE of the one or more tUEs wherein the number of paging retransmissions exceeds the threshold value and that tUE fails to attempt random access within the time period, release a Connection Context of that tUE.

[00157] Example 28 comprises the subject matter of any variation of any of example(s) 23-25, wherein the periodic paging resource comprises a plurality of groups of paging resources in at least one of a frequency domain or a code domain, and wherein the at least the portion of the periodic paging resource comprises at least one of the plurality of groups.

[00158] Example 29 comprises the subject matter of any variation of any of example(s) 23-25, wherein the common paging field indicates that a tSL air interface of the nUE will transition to an Idle State at a next boundary corresponding to a preconfigured condition, and wherein the one or more processors are further configured to employ a common paging cycle value for tUEs in connection with the Idle State.

[00159] Example 30 comprises the subject matter of any variation of any of example(s) 23-25, wherein the common paging field indicates that a tSL air interface of the nUE has transitioned to an Active State from an Idle State. [00160] Example 31 comprises the subject matter of any variation of any of example(s) 23, wherein the paging record field indicates each of the one or more tUEs via one or more of a bitmap or one or more temporary identities associated with the one or more tUEs, wherein each tUE of the one or more tUEs is associated with a distinct bit of the bitmap, and wherein the common paging field indicates that the paging record field comprises the bitmap or the one or more temporary identities.

[00161 ] Example 32 is an apparatus configured to be employed within a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)), comprising: a memory; and one or more processors configured to: process a tSL (5G NR Things SL (Sidelink)) paging message, wherein the tSL paging message comprises a common paging field and a paging record field that indicates each of the one or more tUEs, wherein the tSL paging message is received via a periodic paging resource in a paging frame of the tUE, wherein the paging frame is based on a paging cycle value configured to the tUE; determine, based on the common paging field, a type of the paging record field; determine, based on the paging record field and the type of the paging record field, whether the paging record field indicates whether there is pending DL (downlink) data for the tUE; and in response to the paging record field indicating that there is pending DL data for the tUE: perform a random access procedure; and transition to a tSL-RRC (Radio Resource Control)-Active State.

[00162] Example 33 comprises the subject matter of any variation of any of example(s) 32, wherein the one or more processors are further configured to determine whether the paging record field indicates whether there is pending DL data based on a determination whether the paging record field indicates the tUE via a bit of a bitmap or based on a determination whether the paging record field indicates a temporary identity of the tUE.

[00163] The above description of illustrated embodiments of the subject disclosure, including what is described in the Abstract, is not intended to be exhaustive or to limit the disclosed embodiments to the precise forms disclosed. While specific embodiments and examples are described herein for illustrative purposes, various modifications are possible that are considered within the scope of such embodiments and examples, as those skilled in the relevant art can recognize.

[00164] In this regard, while the disclosed subject matter has been described in connection with various embodiments and corresponding Figures, where applicable, it is to be understood that other similar embodiments can be used or modifications and additions can be made to the described embodiments for performing the same, similar, alternative, or substitute function of the disclosed subject matter without deviating therefrom. Therefore, the disclosed subject matter should not be limited to any single embodiment described herein, but rather should be construed in breadth and scope in accordance with the appended claims below.

[00165] In particular regard to the various functions performed by the above described components or structures (assemblies, devices, circuits, systems, etc.), the terms (including a reference to a "means") used to describe such components are intended to correspond, unless otherwise indicated, to any component or structure which performs the specified function of the described component (e.g., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary implementations. In addition, while a particular feature may have been disclosed with respect to only one of several implementations, such feature may be combined with one or more other features of the other implementations as may be desired and advantageous for any given or particular application.

Claims

CLAIMS What is claimed is:

1 . An apparatus configured to be employed within a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)), comprising:

a memory; and

one or more processors configured to:

employ a tSL (5G NR Things SL (Sidelink))-RRC (Radio Resource Control) State, wherein the tSL-RRC State is one of a tSL-RRC-Active State, a tSL-RRC-ldle State, or a tSL-Deep-PSM (Power Saving Mode) State;

maintain a Connection Context with a nUE (network UE) and monitor a paging channel from the nUE when employing the tSL-RRC-Active State or the tSL-RRC-ldle State; and

monitor one or more DL (downlink) channels from the nUE when employing the tSL-RRC-Active State,

wherein the tSL-RRC-Active State is associated with greater power consumption than the tSL-RRC-ldle State, which is associated with greater power consumption than the tSL-RRC-Deep-PSM State.

2. The apparatus of claim 1 , wherein the tSL-RRC State is the tSL-RRC-Active State, and wherein the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-ldle state in response to an expiration of a timer that measures time since a most recent data activity involving the tUE.

3. The apparatus of claim 2, wherein the one or more processors are further configured to determine a paging configuration prior to transitioning the tSL-RRC State to the tSL-RRC-ldle State, wherein the paging configuration is based on tSL messaging exchanged with the nUE.

4. The apparatus of any of claims 1 -3, wherein the tSL-RRC State is the tSL-RRC- Active State, and wherein the one or more processors are further configured to exchange data with the nUE via a tSL air interface.

5. The apparatus of claim 1 , wherein the tSL-RRC State is the tSL-RRC-Active State, and wherein the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-Deep-PSM State in response to an expiration of a timer that measures the time since the most recent data activity involving the tUE.

6. The apparatus of claim 5, wherein the one or more processors are further configured to determine a duration of the tSL-RRC-Deep-PSM State prior to

transitioning the tSL-RRC State to the tSL-RRC-Deep-PSM State, wherein the duration of the tSL-RRC-Deep-PSM State is based on tSL messaging exchanged with the nUE.

7. The apparatus of claim 1 , wherein the tSL-RRC State is the tSL-RRC-ldle State, and wherein the one or more processors are further configured to transition the tSL- RRC State to the tSL-RRC-Deep-PSM State in response to an expiration of a timer that measures the time since the most recent paging involving the tUE.

8. The apparatus of claim 7, wherein the one or more processors are further configured to determine a duration of the tSL-RRC-Deep-PSM State prior to

9. The apparatus of any of claims 1 , 7, or 8, wherein the tSL-RRC State is the tSL- RRC-ldle state, and wherein, in response to the monitored paging channel indicating data activity associated with the tUE, the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-Active State via performing random access.

10. The apparatus of claim 1 , wherein the tSL-RRC State is the tSL-RRC-Deep-PSM State, wherein the one or more processors are further configured to:

release the Connection Context; and

in response to the expiration of a duration of the tSL-RRC-Deep-PSM State, transition the tSL-RRC State to the tSL-RRC-Active State via performing discovery and random access.

1 1 . The apparatus of claim 1 , wherein the tSL-RRC State is the tSL-RRC-Deep-PSM State, wherein the one or more processors are further configured to maintain the Connection Context and a paging configuration, and wherein, in in response to the expiration of a duration of the tSL-RRC-Deep-PSM State, the one or more processors are further configured to transition the tSL-RRC State to the tSL-RRC-ldle State.

12. An apparatus configured to be employed within a nUE (network UE (User Equipment)), comprising:

a memory; and

one or more processors configured to:

maintain a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)) Connection Context for each tUE of a set of tUEs, wherein each tUE of the set of tUEs is in a tSL (5G NR Things SL (Sidelink))-RRC (Radio Resource Control)-Active State or a tSL-RRC-ldle State;

determine, for each tUE of the set of tUEs, whether DL (downlink) data is pending for that tUE; and

for each tUE for which DL data is pending:

notify that tUE via a tSL paging channel message to return to the tSL-RRC-Active State when that tUE is in the tSL-RRC-ldle State; and schedule the DL data pending for that tUE for transmission via a DL control channel message when that tUE is in the tSL-RRC-Active State.

13. The apparatus of claim 12, wherein the one or more processors are further configured to:

determine a paging configuration for a first tUE of the set of tUEs, wherein the first tUE is in the tSL-RRC-Active State; and

generate tSL messaging that indicates the paging configuration for the first tUE prior to the first tUE transitioning to the tSL-RRC-ldle State.

14. The apparatus of claim 13, wherein the first tUE has a first device type, and wherein the tSL messaging indicates the paging configuration for each tUE of the set of tUEs that has the first device type.

15. The apparatus of claim 12, wherein each tUE of the set of tUEs is in the tSL- RRC-ldle State, and wherein the one or more processors are further configured to transition a tSL air interface of the nUE to an Idle state.

16. The apparatus of claim 15, wherein the tSL messaging indicates the paging configuration for each tUE of the set of tUEs.

17. The apparatus of any of claims 12-16, wherein the one or more processors are further configured to:

determine a Deep PSM (Power Saving Mode) duration for a second tUE of the set of tUEs; and

generate tSL messaging that indicates the Deep PSM duration for the second tUE prior to the second tUE transitioning to a tSL-RRC-Deep-PSM State.

18. The apparatus of claim 17, wherein the second tUE is the only tUE of the set of tUEs in the tSL-RRC- Active State or in the tSL-RRC-ldle State, and wherein the one or more processors are further configured to:

determine a minimum remaining Deep PSM duration among a set of Deep PSM durations for tUEs, wherein the set of Deep PSM durations comprises the Deep PSM duration for the second tUE; and

transition a tSL air interface of the nUE to a Deep PSM state for a time less than the minimum remaining Deep PSM duration.

19. The apparatus of any of claims 12-16, wherein the one or more processors are further configured to maintain at least a partial Connection Context for a third tUE in a tSL-RRC-Deep-PSM State.

20. The apparatus of claim 19, wherein additional DL data is pending for the third tUE, and wherein the one or more processors are further configured to:

buffer the additional DL data;

if the third tUE transitions to the tSL-RRC-ldle State, notify the third tUE via an additional tSL paging channel message to return to the tSL-RRC-Active State; and schedule the additional DL data pending for the third tUE for transmission via an additional DL control channel message when the third tUE is in the tSL-RRC-Active State.

21 . An apparatus configured to be employed within a nUE (network UE (User Equipment)), comprising:

a memory; and one or more processors configured to:

determine one or more tUEs (5G (Fifth Generation) NR (New Radio) Things UEs) for which DL (downlink) data is pending in a buffer;

generate a tSL (5G NR Things SL (Sidelink)) paging message for the one or more tUEs, wherein the tSL paging message comprises a common paging field and a paging record field that indicates each of the one or more tUEs;

determine a paging frame for the one or more tUEs based on a paging cycle value for the one or more tUEs;

schedule the tSL paging message to at least a portion of a periodic paging resource associated with a tSL paging channel in the paging frame; and

pass the tSL paging message to a tSL-PHY (Physical Layer) for communication via the periodic paging resource over a tSL air interface.

22. The apparatus of claim 21 , wherein the paging record field indicates each of the one or more tUEs via a bitmap, wherein each tUE of the one or more tUEs is associated with a distinct bit of the bitmap, and wherein the common paging field indicates that the paging record field comprises the bitmap.

23. The apparatus of claim 21 , wherein the paging record field indicates the one or more tUEs via one or more temporary identities associated with the one or more tUEs, and wherein the common paging field indicates that the paging record field comprises the one or more temporary identities.

24. The apparatus of any of claims 21 -23, wherein the one or more processors are further configured to:

determine a number of paging retransmissions for each tUE of the one or more tUEs; and

for each tUE of the one or more tUEs, release a Connection Context of that tUE when the number of paging retransmissions exceeds a threshold value.

25. The apparatus of any of claims 21 -23, wherein the one or more processors are further configured to:

determine a number of paging retransmissions for each tUE of the one or more tUEs; for each tUE of the one or more tUEs, when the number of paging retransmissions exceeds a threshold value, determine whether that tUE attempts random access within a time period after the most recent paging retransmission, wherein the time period is based on a timer indicating a maximum idle time without receiving paging plus a margin time; and

for each tUE of the one or more tUEs wherein the number of paging

retransmissions exceeds the threshold value and that tUE fails to attempt random access within the time period, release a Connection Context of that tUE.

26. The apparatus of any of claims 21 -23, wherein the periodic paging resource comprises a plurality of groups of paging resources in at least one of a frequency domain or a code domain, and wherein the at least the portion of the periodic paging resource comprises at least one of the plurality of groups.

27. The apparatus of any of claims 21 -23, wherein the common paging field indicates that a tSL air interface of the nUE will transition to an Idle State at a next boundary corresponding to a preconfigured condition, and wherein the one or more processors are further configured to employ a common paging cycle value for tUEs in connection with the Idle State.

28. The apparatus of any of claims 21 -23, wherein the common paging field indicates that a tSL air interface of the nUE has transitioned to an Active State from an Idle State.

29. An apparatus configured to be employed within a tUE (5G (Fifth Generation) NR (New Radio) Things UE (User Equipment)), comprising:

a memory; and

one or more processors configured to:

process a tSL (5G NR Things SL (Sidelink)) paging message, wherein the tSL paging message comprises a common paging field and a paging record field that indicates each of the one or more tUEs, wherein the tSL paging message is received via a periodic paging resource in a paging frame of the tUE, wherein the paging frame is based on a paging cycle value configured to the tUE;

determine, based on the common paging field, a type of the paging record field; determine, based on the paging record field and the type of the paging record field, whether the paging record field indicates whether there is pending DL (downlink) data for the tUE; and

in response to the paging record field indicating that there is pending DL data for the tUE:

perform a random access procedure; and

transition to a tSL-RRC (Radio Resource Control)-Active State.

30. The apparatus of claim 29, wherein the one or more processors are further configured to determine whether the paging record field indicates whether there is pending DL data based on a determination whether the paging record field indicates the tUE via a bit of a bitmap or based on a determination whether the paging record field indicates a temporary identity of the tUE.