Network-initiated on-demand zero-energy paging method and device

Abstract

To improve energy efficiency by maximizing a battery life of a network device.SOLUTION: A WTRU comprises at least one antenna and first and second transceivers coupled to the at least one antenna. The at least one antenna and the first transceiver are configured to receive a first signal from a network. The first transceiver is further configured to decode an energy signature of the first signal by extracting energy from the first signal and comparing a time separation between energy threshold events. The first transceiver is configured to activate the second transceiver when the decoded energy signature matches the configured energy signature. The at least one antenna and the second transceiver are configured to receive a second signal from the network.SELECTED DRAWING: Figure 39

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 62 / 593,631, filed December 1, 2017, the contents of which are incorporated herein by reference. [Background technology]

[0002] Advances in technology and connectivity for devices (e.g., mobile devices, appliances, consumer goods, wearables, automation devices, servers, notebooks, transmitters, receivers, etc.) are leading these devices to benefit from network connectivity. Emerging application areas driving this need include smart cities, smart homes, smart energy grids, mobile health devices, vehicle telematics, automated agriculture, asset tracking, environmental monitoring, industrial monitoring, and infrastructure monitoring. In many emerging applications, energy efficiency is a key requirement as it is desirable to maximize the battery life of connected networked devices. Summary of the Invention

[0003] A wireless transmit / receive unit (WTRU) may include one or more antennas and a first transceiver operably coupled to the one or more antennas. The one or more antennas and the first transceiver may be configured to receive a first signal from a network using zero energy from the WTRU. The one or more antennas and the first transceiver may be further configured to extract energy from the first signal. The first transceiver may be further configured to check a time separation between energy threshold events to decode an energy signature of the first signal. The first transceiver may be further configured to activate a second transceiver operably coupled to the one or more antennas if the decoded energy signature matches a stored energy signature, the second transceiver being powered by the WTRU. The one or more antennas and the second transceiver may be configured to receive a second signal from the network.

[0004] A wireless transmit / receive unit (WTRU) may include one or more antennas and a first transceiver operably coupled to the one or more antennas. The one or more antennas and the first transceiver may be configured to receive a first signal from a network using zero energy of the WTRU. The one or more antennas and the first transceiver may be further configured to extract energy from the first signal. The first transceiver may be further configured to examine a time separation between energy threshold events to decode an energy signature of the first signal. The energy threshold event may be generated by determining that an amount of extracted energy stored in a temporary storage element exceeds a threshold. The time separation between the energy threshold events may be based on one or more of a capacity of the temporary storage element and a configured value of the threshold. The first transceiver may be further configured to convert the energy threshold event to a digital signal by transferring the extracted energy from the temporary storage element to a permanent storage element. The first transceiver may be further configured to activate a second transceiver operably coupled to the one or more antennas if the decoded energy signature matches the stored energy signature. The second transceiver may be powered by the WTRU. The one or more antennas and the second transceiver may be configured to receive a second signal from a network.

[0005] A method for use in a wireless transmit / receive unit (WTRU) may include receiving a first signal from a network using a first transceiver. The first transceiver may use zero energy from the WTRU. Energy may be extracted from the first signal. A time separation between energy threshold events may be checked to decode an energy signature of the first signal. If the decoded energy signature matches a stored energy signature, a second transceiver operably coupled to one or more antennas may be activated. The second transceiver may be powered by the WTRU. A second signal may be received from the network using the second transceiver powered by the WTRU. [Brief description of the drawings]

[0006] A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings in which like reference numbers refer to similar elements and in which: [Figure 1A] FIG. 1 is a system diagram illustrating an example communication system in which one or more disclosed embodiments may be implemented. [Figure 1B] 1A is a system diagram illustrating an example wireless transmit / receive unit (WTRU) that may be used within the communications system illustrated in FIG. 1A, according to an embodiment. [Figure 1C] FIG. 1B is a system diagram illustrating an example radio access network (RAN) and an example core network (CN) that may be used within the communications system illustrated in FIG. 1A, according to an embodiment. [Figure 1D] FIG. 1B is a system diagram illustrating a further exemplary RAN and a further exemplary CN that may be used within the communications system illustrated in FIG. 1A, according to an embodiment. [Diagram 2] 1 illustrates various approaches for connecting multiple devices to the Internet. [Diagram 3] FIG. 1 is a diagram showing a power saving mode (PSM). [Figure 4] FIG. 2 illustrates a discontinuous reception (DRX) cycle. [Diagram 5] FIG. 1 illustrates a PSM that may be used in a conventional IEEE 802.11 system to help stations conserve power. [Figure 6] FIG. 1 illustrates Scheduled Automatic Power Save Delivery (S-APSD). [Figure 7] FIG. 1 illustrates power saving multi-pole (PSMP) delivery. [Figure 8] FIG. 1 illustrates a device power profile in LTE DRX. [Figure 9A] FIG. 1 illustrates a 30-year battery life for a machine type communication (MTC) device achieved with 8 μW leakage power and a 45-hour paging cycle. [Figure 9B] FIG. 13 shows that battery life for an MTC device indicates that 45 hours of paging and transaction cycles may be required to achieve a 30 year battery life if leakage power is assumed to be 8 μW. [Figure 10A] FIG. 1 is a first diagram of the top level architecture of the Facilitator and Interrogator. [Figure 10B] FIG. 2 is a second diagram of the top level architecture of the Facilitator and Interrogator. [Figure 11] FIG. 1 illustrates a top-level radio architecture for a battery-powered device. [Figure 12] FIG. 1 illustrates a top-level depiction of a multi-mode / multi-band device. [Figure 13A] FIG. 1 illustrates an FDD device with a single-band passive transceiver. [Figure 13B] FIG. 1 illustrates an FDD device with a dual-band passive transceiver. [Figure 14A] FIG. 1 illustrates a half-duplex FDD (HD-FDD) device with a single-band passive transceiver. [Figure 14B] A diagram showing an HD-FF device with a dual-band passive transceiver integrated into the RF front-end. [Figure 15] FIG. 2 illustrates a TDD mode device. [Figure 16A] FIG. 1 illustrates a dual-band FDD device. [Figure 16B] FIG. 1 illustrates a single-band FDD device. [Figure 17] FIG. 1 illustrates a radio-triggered wake-up receiver architecture. [Figure 18A] FIG. 1 shows a simplified overview of a single-ended architecture of a passive front-end. [Figure 18B] FIG. 1 shows a simplified overview of a differential or balanced architecture of a passive front end. [Figure 19A] FIG. 1 shows an output waveform VFE in response to a continuously present sinusoidal input r(t). [Figure 19B] FIG. 1 illustrates the response of a passive front-end to a pulsed sine wave. [Figure 20A] FIG. 1 illustrates an embodiment of an analog-to-information (A / I) converter. [Figure 20B] 4A and 4B are diagrams illustrating input and output waveforms of an A / I converter. [Figure 21] FIG. 1 is a circuit diagram showing an analog-to-information converter with automatic sensitivity control. [Figure 22A] FIG. 1 illustrates a single-ended implementation of an A / I converter. [Figure 22B] FIG. 1 illustrates a fully differential or balanced embodiment of an A / I converter. [Diagram 23] FIG. 1 is a circuit diagram showing an alternative implementation of an analog to information converter. [Figure 24] FIG. 1 is a circuit diagram showing a complete overview of a radio triggered wake-up receiver. [Diagram 25]FIG. 1 is a circuit diagram illustrating a passive transceiver architecture. [Figure 26A] FIG. 1 illustrates a stored energy thresholding event counting wake-up command interpreter (ET-CI) for a single input. [Figure 26B] FIG. 1 illustrates stored ET-CI for a multi-input device. [Figure 27A] FIG. 1 illustrates an ET-CI configured for two threshold events from an A / I converter. [Figure 27B] FIG. 1 illustrates an ET-CI configured for three threshold events. [Figure 28A] FIG. 1 illustrates a pulse separation decoding (PSD) data detector. [Figure 28B] FIG. 1 illustrates a single-input stored energy threshold event separation decoding wake-up command interpreter (ETESD-CI). [Figure 28C] FIG. 1 illustrates a three input stored energy threshold event separation decoding wake-up command interpreter (ETESD-CI). [Figure 29] FIG. 1 illustrates a single-input energy threshold event separation decoding command interpreter theory of operation. [Diagram 30] FIG. 2 illustrates a resource cube used to construct a wake-up word. [Diagram 31] FIG. 2 illustrates a transmitter structure used to generate a wake-up command. [Figure 32A] FIG. 1 shows a symbolic representation of an f1 word of strength 3 / 9. [Figure 32B] FIG. 1 shows the (1,f1) wake-up word. [Figure 32C] FIG. 2 illustrates a wake-up word that utilizes a single frequency resource and up to L time resources. [Fig. 32D] FIG. 1 shows the (1,f1) wake-up word. [Figure 33A] (3 / 9,f1) A diagram showing an alternative implementation of the wake-up word. [Figure 33B] (3 / 9,f1) A diagram showing another alternative implementation of the wake-up word. [Figure 34A] FIG. 1 shows a word employing frequency / time resource combinations of (3 / 9,f1) and (1,fk). [Figure 34B] A diagram showing the {(3 / 9,f1),(4 / 9,f2),(1,fk)} words. [Figure 35A] FIG. 1 illustrates a ward employing the same combinations of time and frequency resources (3 / 9,f1) and (1,f2) on two different angular resources θ1 and θ2. [Figure 35B] FIG. 1 shows the [{θ1,(3 / 5,f1)},{θ2,(4 / 9,f1),(1,f2)}] word. [Figure 36A] A diagram showing a wake-up command employing four words (N=4), a single angle per word (m=1), a single frequency (k=1), and five time resources (L=5). [Figure 36B] FIG. 13 illustrates a (3,1,2,9) stored energy threshold event stacking wakeup command employing N=3 words, m=1 angle per word, k=2 frequency, and L=9 time resources. [Figure 37A] A diagram showing a first quantization level of a word employing a single angular resource, a single frequency resource, and eight time resources. [Figure 37B] A diagram showing a second quantization level of a word employing a single angular resource, a single frequency resource, and eight time resources. [Figure 37C] A diagram showing a third quantization level of a word employing a single angular resource, a single frequency resource, and eight time resources. [Figure 37D] A diagram showing a fourth quantization level of a word employing a single angle resource, a single frequency resource, and eight time resources. [Figure 38] FIG. 2 illustrates a constant energy amplitude modulated waveform. [Figure 39] FIG. 1 illustrates elements of a paging system. [Diagram 40] A diagram showing an on-demand zero energy paging procedure. [Figure 41A] A diagram showing eNodeB signals and facilitator signals. [Figure 41B] FIG. 4 illustrates a device signal. [Diagram 42] FIG. 1 illustrates a paging cycle period adaptation procedure. [Figure 43A] A diagram showing eNodeB power profile and signaling. [Figure 43B] FIG. 1 illustrates a device power profile and signals. [Diagram 44] FIG. 1 illustrates an on-demand zero energy wake-up procedure. [Diagram 45] FIG. 2 shows a backscattered and modulated carrier. [Diagram 46] FIG. 13 illustrates an example of a detection procedure. [Figure 47] FIG. 2 illustrates a frequency offset estimator. [Figure 48] FIG. 1 illustrates the deployment of cell clusters that transmit radio beacons on separate frequencies to indicate TA boundaries. [Figure 49] 1 illustrates a wake-up command entry signature allocation procedure initiated by a WTRU. [Figure 50] FIG. 1 illustrates adaptive power transmission for a wake-up process. [Figure 51] FIG. 13 illustrates resource block (RB) usage information sharing aggregate eNB for primary added power estimation. [Figure 52] FIG. 13 illustrates the transmission of a dedicated beacon. [Figure 53] FIG. 2 illustrates the transmission of a dedicated wake-up signal. [Figure 54]A diagram illustrating the call flow for wake-up command energy signature configuration, STA wake-up, and data transfer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] 1A illustrates an example communication system 100 in which one or more disclosed embodiments may be implemented. The communication system 100 may be a multiple access system that provides content, such as voice, data, video, messaging, broadcast, etc., to multiple wireless users. The communication system 100 enables the multiple wireless users to access such content through sharing of system resources, including radio bandwidth. For example, the communication system 100 may employ one or more channel access methods, such as Code Division Multiple Access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Orthogonal FDMA (OFDMA), Single Carrier FDMA (SC-FDMA), Zero-Tailed Unique Word DFT-Spread OFDM (ZT UW DTS-s OFDM), Unique Word OFDM (UW-OFDM), Resource Block Filtered OFDM, Filter Bank Multi-Carrier (FBMC), etc.

[0008] 1A, the communications system 100 may include wireless transmit / receive units (WTRUs) 102a, 102b, 102c, 102d, a RAN 104 / 113, a CN 106 / 115, a public switched telephone network (PSTN) 108, the Internet 110, and other networks 112, although it will be understood that the disclosed embodiments contemplate any number of WTRUs, base stations, networks, and / or network elements. Each of the WTRUs 102a, 102b, 102c, 102d may be any type of device configured to operate and / or communicate in a wireless environment. For example, the WTRUs 102a, 102b, 102c, 102d (any of which may be referred to as a “station” and / or “STA”) may be configured to transmit and / or receive wireless signals and may include user equipment (UE), mobile stations, fixed or mobile subscriber units, subscription-based units, pagers, cellular phones, PDAs, smartphones, laptops, netbooks, personal computers, wireless sensors, hotspots or Mi-Fi devices, IoT devices, watches or other wearables, head mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in the context of industrial and / or automated processing chains), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Any of the WTRUs 102a, 102b, 102c, and 102d may be interchangeably referred to as a UE.

[0009] The communication system 100 may also include a base station 114a and / or a base station 114b. Each of the base stations 114a, 114b may be any type of device configured to wirelessly interface with at least one of the WTRUs 102a, 102b, 102c, 102d to facilitate access to one or more communication networks, e.g., the CN 106 / 115, the Internet 110, and / or other networks 112. For example, the base stations 114a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a home Node B, a home eNode B, a gNB, an NR NodeB, a site controller, an access point (AP), a wireless router, etc. Although the base stations 114a, 114b are each shown as a single element, it will be understood that the base stations 114a, 114b may include any number of interconnected base stations and / or network elements.

[0010] The base station 114a may be part of the RAN 104 / 113, which may also include other base stations and / or network elements (not shown), e.g., a base station controller (BSC), a radio network controller (RNC), relay nodes, etc. The base station 114a and / or the base station 114b may be configured to transmit and / or receive wireless signals on one or more carrier frequencies, which may be referred to as cells (not shown). These frequencies may be licensed spectrum, unlicensed spectrum, or a combination of licensed and unlicensed spectrum. A cell may provide coverage for wireless services to a particular geographic area, which may be relatively fixed or may change over time. A cell may be further divided into cell sectors. For example, the cell associated with the base station 114a may be divided into three sectors. Thus, in one embodiment, the base station 114a may include three transceivers, i.e., one transceiver for each sector of the cell. In an embodiment, the base station 114a may employ MIMO technology and may utilize multiple transceivers for each sector of the cell. For example, beamforming may be used to transmit and / or receive signals in desired spatial directions.

[0011] The base stations 114a, 114b may communicate with one or more of the WTRUs 102a, 102b, 102c, 102d over an air interface 116, which may be any suitable wireless communication link (e.g., radio frequency (RF), microwave, centimeter wave, micrometer wave, infrared (IR), ultraviolet (UV), visible light, etc.). The air interface 116 may be established using any suitable radio access technology (RAT).

[0012] More specifically, as described above, the communication system 100 may be a multiple access system and may employ one or more channel access schemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, etc. For example, the base station 114a in the RAN 104 / 113 and the WTRUs 102a, 102b, 102c may implement a radio technology such as Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access (UTRA), which may establish the air interface 115 / 116 / 117 using Wideband CDMA (WCDMA®). WCDMA may include communication protocols such as High Speed ​​Packet Access (HSPA) and / or Evolved HSPA (HSPA+). HSPA may include High Speed ​​Downlink (DL) Packet Access (HSDPA) and / or High Speed ​​UL Packet Access (HSUPA).

[0013] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as Evolved UMTS Terrestrial Radio Access (E-UTRA), which may establish the air interface 116 using Long Term Evolution (LTE) and / or LTE-Advanced (LTE-A) and / or LTE-Advanced Pro (LTE-A Pro).

[0014] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement a radio technology such as New Radio (NR) radio access, which may establish the air interface 116 using NR.

[0015] In an embodiment, the base station 114a and the WTRUs 102a, 102b, 102c may implement multiple radio access technologies. For example, the base station 114a and the WTRUs 102a, 102b, 102c may implement both LTE radio access and NR radio access, e.g., using a dual connectivity (DC) principle. Thus, the air interface utilized by the WTRUs 102a, 102b, 102c may be characterized by multiple types of radio access technologies and / or transmissions sent to / from multiple types of base stations (e.g., eNBs and gNBs).

[0016] In other embodiments, the base station 114a and the WTRUs 102a, 102b, 102c may implement a wireless technology such as, for example, IEEE 802.11 (i.e., Wireless Fidelity (WiFi), IEEE 802.16 (i.e., Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000, CDMA2000 1X, CDMA2000EV-DO, Interim Standard 2000 (IS-2000), Interim Standard 95 (IS-95), Interim Standard 856 (IS-856), GSM, Enhanced Data Rates for GSM Evolution (EDGE), GSM EDGE (GERAN), etc.

[0017] The base station 114b in FIG. 1A may be, for example, a wireless router, a Home Node B, a Home eNode B, or an access point, and may utilize any suitable RAT to facilitate wireless connectivity in a localized area, such as an office, a home, a vehicle, a campus, an industrial facility, an air corridor (e.g., for use by drones), a roadway, etc. In one embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.11 to establish a wireless local area network (WLAN). In an embodiment, the base station 114b and the WTRUs 102c, 102d may implement a radio technology such as IEEE 802.15 to establish a wireless personal area network (WPAN). In yet another embodiment, the base station 114b and the WTRUs 102c, 102d may utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE, LTE-A, LTE-A Pro, NR, etc.) to establish a picocell or femtocell. 1A, base station 114b may have a direct connection to the Internet 110. Thus, base station 114b may not be required to access the Internet 110 via CN 106 / 115.

[0018] The RAN 104 / 113 may be in communication with the CN 106 / 115, which may be any type of network configured to provide voice, data, application, and / or Voice over Internet Protocol (VoIP) services to one or more of the WTRUs 102a, 102b, 102c, 102d. The data may have various quality of service (QoS) requirements, such as separate throughput requirements, latency requirements, error tolerance requirements, reliability requirements, data throughput requirements, mobility requirements, etc. The CN 106 / 115 may provide call control, billing services, mobile location services, prepaid calling, Internet connectivity, video distribution, etc., and / or perform high level security functions, such as user authentication. Although not shown in FIG. 1A, it will be understood that the RAN 104 / 113 and / or the CN 106 / 115 may be in direct or indirect communication with other RANs employing the same RAT as the RAN 104 / 113 or a different RAT. For example, in addition to being connected to the RAN 104 / 113, which may utilize NR radio technology, the CN 106 / 115 may also be in communication with another RAN (not shown) that employs GSM, UMTS, CDMA2000, WiMAX, E-UTRA, or WiFi radio technology.

[0019] The CN 106 / 115 may also serve as a gateway for the WTRUs 102a, 102b, 102c, 102d to access the PSTN 108, the Internet 110, and / or other networks 112. The PSTN 108 may include a circuit-switched telephone network providing Plain Old Telephone Service (POTS). The Internet 110 may include a global system of interconnected computer networks and devices that use common communication protocols, such as TCP, UDP, and / or IP in the TCP / IP Internet protocol suite. The networks 112 may include wired and / or wireless communication networks owned and / or operated by other service providers. For example, the networks 112 may include another CN connected to one or more RANs that may employ the same RAT as the RAN 104 / 113 or a different RAT.

[0020] Some or all of the WTRUs 102a, 102b, 102c, 102d in the communications system 100 may include multi-mode capabilities (e.g., the WTRUs 102a, 102b, 102c, 102d may include multiple transceivers to communicate with separate wireless networks over separate wireless links). For example, the WTRU 102c shown in FIG. 1A may be configured to communicate with a base station 114a that may employ a cellular-based wireless technology and with a base station 114b that may employ an IEEE 802 wireless technology.

[0021] Figure 1B is a system diagram illustrating an example WTRU 102. As shown in Figure 1B, the WTRU 102 may include, among other things, a processor 118, a transceiver 120, a transmit / receive element 122, a speaker / microphone 124, a keypad 126, a display / touchpad 128, non-removable memory 130, removable memory 132, a power source 134, a GPS chipset 136, and / or other peripherals 138. It will be understood that the WTRU 102 may include any sub-combination of the above-mentioned elements while remaining consistent with an embodiment.

[0022] The processor 118 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), multiple microprocessors, one or more microprocessors associated with a DSP core, a controller, a microcontroller, an ASIC, an FPGA circuit, any other type of integrated circuit (IC), a state machine, etc. The processor 118 may perform signal coding, data processing, power control, input / output processing, and / or any other functionality that enables the WTRU 102 to operate in a wireless environment. The processor 118 may be coupled to the transceiver 120, which may be coupled to the transmit / receive element 122. Although FIG. 1B depicts the processor 118 and the transceiver 120 as separate components, it will be understood that the processor 118 and the transceiver 120 may be integrated together in an electronic package or chip.

[0023] The transmit / receive element 122 may be configured to transmit signals to or receive signals from a base station (e.g., the base station 114a) via the air interface 116. For example, in one embodiment, the transmit / receive element 122 may be an antenna configured to transmit and / or receive RF signals. In an embodiment, the transmit / receive element 122 may be an emitter / detector configured to transmit and / or receive, for example, IR, UV, or visible light signals. In yet another embodiment, the transmit / receive element 122 may be configured to transmit and / or receive both RF and light signals. It will be understood that the transmit / receive element 122 may be configured to transmit and / or receive any combination of wireless signals.

[0024] 1B as a single element, the WTRU 102 may include any number of transmit / receive elements 122. More specifically, the WTRU 102 may employ MIMO technology. Thus, in one embodiment, the WTRU 102 may include two or more transmit / receive elements 122 (e.g., multiple antennas) for transmitting and receiving wireless signals over the air interface 116.

[0025] The transceiver 120 may be configured to modulate signals to be transmitted by the transmit / receive element 122 and to demodulate signals received by the transmit / receive element 122. As mentioned above, the WTRU 102 may have multi-mode capabilities. Thus, the transceiver 120 may include multiple transceivers to enable the WTRU 102 to communicate via multiple RATs, such as, for example, NR and IEEE 802.11.

[0026] The processor 118 of the WTRU 102 may be coupled to and may receive user input data from the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128 (e.g., a liquid crystal display (LCD) display unit or an organic light emitting diode (OLED) display unit). The processor 118 may also output user data to the speaker / microphone 124, the keypad 126, and / or the display / touchpad 128. The processor 118 may access information and store data in any type of suitable memory, e.g., non-removable memory 130 and / or removable memory 132. The non-removable memory 130 may include RAM, ROM, a hard disk, or any other type of memory storage device. The removable memory 132 may include a SIM card, a memory stick, an SD memory card, etc. In other embodiments, the processor 118 may access information and store data in memory that is not physically located on the WTRU 102, e.g., a server or a home computer (not shown).

[0027] The processor 118 may receive power from the power source 134 and may be configured to distribute and / or control the power to other components in the WTRU 102. The power source 134 may be any suitable device for powering the WTRU 102. For example, the power source 134 may include one or more dry batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel-metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, etc.

[0028] The processor 118 may also be coupled to a GPS chipset 136, which may be configured to provide location information (e.g., longitude and latitude) regarding a current location of the WTRU 102. The WTRU 102 may receive location information over the air interface 116 from a base station (e.g., base stations 114a, 114b) in addition to or in lieu of the information from the GPS chipset 136, and / or determine its location based on the timing of signals being received from two or more neighboring base stations. It will be appreciated that the WTRU 102 may obtain location information through any suitable location determination method while remaining consistent with an embodiment.

[0029] The processor 118 may be further coupled to other peripherals 138, which may include one or more software and / or hardware modules that provide additional features, functionality, and / or wired or wireless connectivity. For example, the peripherals 138 may include an accelerometer, an e-compass, a satellite transceiver, a digital camera (for photos and / or videos), a USB port, a vibration device, a television transceiver, a hands-free headset, a Bluetooth module, a frequency modulation (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, a virtual reality and / or augmented reality (VR / AR) device, an activity tracker, and the like. The peripherals 138 may include one or more sensors, which may be one or more of a gyroscope, an accelerometer, a Hall effect sensor, a magnetometer, an orientation sensor, a proximity sensor, a temperature sensor, a time sensor, a geolocation sensor, an altimeter, a light sensor, a touch sensor, a magnetometer, a barometer, a gesture sensor, a biometric sensor, and / or a humidity sensor.

[0030] The WTRU 102 may include a full-duplex radio where the transmission and reception of some or all of the signals (e.g., associated with a particular subframe for both the UL (e.g., for transmission) and the downlink (e.g., for reception)) may be parallel and / or simultaneous. The full-duplex radio may include an interference management unit 139 to reduce and / or substantially eliminate self-interference via signal processing in hardware (e.g., a choke) or via a processor (e.g., via a separate processor (not shown) or via the processor 118). In an embodiment, the WRTU 102 may include a half-duplex radio where the transmission and reception of some or all of the signals (e.g., associated with a particular subframe for either the UL (e.g., for transmission) or the downlink (e.g., for reception)) may be parallel and / or simultaneous.

[0031] 1C is a system diagram illustrating the RAN 104 and the CN 106 according to an embodiment. As mentioned above, the RAN 104 may employ E-UTRA radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 104 may also be in communication with the CN 106.

[0032] The RAN 104 may include eNode-Bs 160a, 160b, 160c, although it will be understood that the RAN 104 may include any number of eNode-Bs while remaining consistent with an embodiment. The eNode-Bs 160a, 160b, 160c may each include one or more transceivers for communicating with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the eNode-Bs 160a, 160b, 160c may implement MIMO techniques. Thus, the eNode-B 160a may use multiple antennas, for example, to transmit wireless signals to and / or receive wireless signals from the WTRU 102a.

[0033] Each of the eNode-Bs 160a, 160b, 160c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, etc. As shown in FIG 1C, the eNode-Bs 160a, 160b, 160c may communicate with each other via an X2 interface.

[0034] 1C may include a Mobility Management Entity (MME) 162, a Serving Gateway (SGW) 164, and a Packet Data Network (PDN) Gateway (or PGW) 166. Although each of the above elements is shown as part of the CN 106, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0035] The MME 162 may be connected to each of the eNode-Bs 162a, 162b, 162c in the RAN 104 via an S1 interface and may act as a control node. For example, the MME 162 may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, activating / deactivating bearers, selecting a particular serving gateway during initial attachment of the WTRUs 102a, 102b, 102c, etc. The MME 162 may provide a control plane function for switching between the RAN 104 and other RANs (not shown) employing other radio technologies such as GSM and / or WCDMA.

[0036] The SGW 164 may be connected to each of the eNode Bs 160a, 160b, 160c in the RAN 104 via an S1 interface. The SGW 164 may generally route and forward user data packets to / from the WTRUs 102a, 102b, 102c. The SGW 164 may perform other functions, such as fixing the user plane during handover between eNode Bs, triggering paging when DL data is available for the WTRUs 102a, 102b, 102c, managing and storing the context of the WTRUs 102a, 102b, 102c, etc.

[0037] The SGW 164 may be connected to a PGW 166, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices.

[0038] The CN 106 may facilitate communication with other networks. For example, the CN 106 may provide the WTRUs 102a, 102b, 102c with access to circuit-switched networks, such as the PSTN 108, to facilitate communication between the WTRUs 102a, 102b, 102c and traditional landline communication devices. For example, the CN 106 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 106 and the PSTN 108. The CN 106 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers.

[0039] Although the WTRU is depicted in FIGS. 1A-1D as a wireless terminal, in certain representative embodiments it is contemplated that such a terminal may be capable of using a wired communications interface (e.g., temporarily or permanently) with the communications network.

[0040] In an exemplary embodiment, the other network 112 may be a WLAN.

[0041] A WLAN in infrastructure basic service set (BSS) mode may have an access point (AP) for the BSS and one or more stations (STAs) associated with the AP. The AP may have access or interface to a distribution system (DS) or another type of wired / wireless network that carries traffic to and from the BSS. Traffic to the STAs originating from outside the BSS may arrive through the AP and be distributed to the STAs. Traffic originating from the STAs to destinations outside the BSS may be sent to the AP and delivered to the respective destination. Traffic between STAs in the BSS may be sent through the AP, for example, if the source STA can send traffic to the AP, which can then deliver it to the destination STA. Traffic between STAs in the BSS may be considered and / or referred to as peer-to-peer traffic. Peer-to-peer traffic may be sent between (e.g., directly between) the source and destination STAs using a direct link setup (DLS). In certain representative embodiments, the DLS may use 802.11e DLS or 802.11z Tunneled DLS (TDLS). A WLAN using an Independent BSS (IBSS) mode may have no APs, and STAs within or using an IBSS (e.g., all of the STAs) may communicate directly with each other. The IBSS mode of communication may sometimes be referred to herein as an "ad-hoc" mode of communication.

[0042] When using an 802.11ac infrastructure mode of operation or a similar mode of operation, an AP may transmit a beacon on a fixed channel, such as a primary channel. The primary channel may be of fixed width (e.g., a 20 MHz wide bandwidth) or dynamically set via signaling. The primary channel may be the operating channel of the BSS and may be used by STAs to establish a connection with the AP. In certain representative embodiments, for example in an 802.11 system, a carrier sense multiple access with collision avoidance (CSMA / CA) scheme may be implemented. With CSMA / CA, STAs (e.g., every STA), including the AP, may sense the primary channel. If the primary channel is sensed / detected by a particular STA and / or determined to be busy, the particular STA may back out. One STA (e.g., only one station) may transmit at any given time in a given BSS.

[0043] High-throughput (HT) STAs may use 40 MHz wide channels for communication, for example, via combining a primary 20 MHz channel with adjacent or non-adjacent 20 MHz channels to form the 40 MHz wide channel.

[0044] A Very High Throughput (VHT) STA may support channels of 20 MHz, 40 MHz, 80 MHz, and / or 160 MHz width. A 40 MHz channel and / or an 80 MHz channel may be formed by combining adjacent 20 MHz channels. A 160 MHz channel may be formed by combining eight adjacent 20 MHz channels or by combining two non-adjacent 80 MHz channels (which may be referred to as an 80+80 configuration). For the 80+80 configuration, the data may be passed through a segment parser after channel encoding, which may split the data into two streams. Inverse Fast Fourier Transform (IFFT) processing and time domain processing may be performed separately on each stream. The streams may be mapped onto two 80 MHz channels, and the data may be transmitted by the transmitting STA. At the receiver of the receiving STA, the above operations for the 80+80 configuration may be reversed, and the combined data may be sent to the Medium Access Control (MAC).

[0045] Sub-1 GHz modes of operation are supported by 802.11af and 802.11ah. Channel operating bandwidths and carriers are reduced in 802.11af and 802.11ah compared to those used in 802.11n and 802.11ac. 802.11af supports 5 MHz, 10 MHz, and 20 MHz bandwidths in the TV White Space (TVWS) spectrum, and 802.11ah supports 1 MHz, 2 MHz, 4 MHz, 8 MHz, and 16 MHz bandwidths using non-TVWS spectrum. According to a representative embodiment, 802.11ah can support meter-type control / machine-type communication, such as MTC devices in macro coverage areas. MTC devices can have limited capabilities, including specific capabilities, such as support for (e.g., only support for) specific and / or limited bandwidths. MTC devices can include batteries with above-threshold battery life (e.g., to maintain very long battery life).

[0046] A WLAN system capable of supporting multiple channels and channel bandwidths, e.g., 802.11n, 802.11ac, 802.11af, and 802.11ah, includes a channel that may be designated as a primary channel. The primary channel may have a bandwidth equal to the largest common operating bandwidth supported by all STAs in the BSS. The bandwidth of the primary channel may be set and / or limited by the STA that supports the smallest bandwidth operating mode among all STAs operating in the BSS. In the 802.11ah example, for a STA (e.g., an MTC type device) that supports (e.g., only supports) the 1 MHz mode, the primary channel may be 1 MHz wide, even if the AP and other STAs in the BSS support 2 MHz, 4 MHz, 8 MHz, 16 MHz, and / or other channel bandwidth operating modes. Carrier sensing and / or network allocation vector (NAV) setting may depend on the status of the primary channel. If the primary channel is busy, for example due to STAs (that only support a 1 MHz mode of operation) transmitting to the AP, then the entire set of available frequency bands may be considered busy even though most of those frequency bands may remain idle and therefore available.

[0047] In the United States, the available frequency bands that can be used by 802.11ah are from 902MHz to 928MHz. In South Korea, the available frequency bands are from 917.5MHz to 923.5MHz. In Japan, the available frequency bands are from 916.5MHz to 927.5MHz. The total available bandwidth for 802.11ah is 6MHz to 26MHz depending on the country code.

[0048] 1D is a system diagram illustrating the RAN 113 and the CN 115 according to an embodiment. As mentioned above, the RAN 113 may employ NR radio technology to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. The RAN 113 may also be in communication with the CN 115.

[0049] The RAN 113 may include gNBs 180a, 180b, 180c, although it will be understood that the RAN 113 may include any number of gNBs while remaining consistent with an embodiment. The gNBs 180a, 180b, 180c may each include one or more transceivers to communicate with the WTRUs 102a, 102b, 102c over the air interface 116. In one embodiment, the gNBs 180a, 180b, 180c may implement MIMO technology. For example, the gNBs 180a, 180b may utilize beamforming to transmit signals to and / or receive signals from the gNBs 180a, 180b, 180c. Thus, the gNB 180a may use multiple antennas to transmit wireless signals to and / or receive wireless signals from the WTRU 102a, for example. In an embodiment, the gNBs 180a, 180b, 180c may implement carrier aggregation techniques. For example, the gNB 180a may transmit multiple component carriers to the WTRU 102a (not shown). A subset of these component carriers may be on an unlicensed spectrum, while the remaining component carriers may be on a licensed spectrum. In an embodiment, the gNBs 180a, 180b, 180c may implement coordinated multipoint (CoMP) techniques. For example, the WTRU 102a may receive coordinated transmissions from the gNBs 180a and 180b (and / or gNB 180c).

[0050] The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using transmissions associated with a scalable numerology. For example, the OFDM symbol spacing and / or OFDM subcarrier spacing may be different for different transmissions, different cells, and / or different portions of the wireless transmission spectrum. The WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using subframes or transmission time intervals (TTIs) of different or scalable lengths (e.g., including different numbers of OFDM symbols and / or different lengths of absolute time duration).

[0051] The gNBs 180a, 180b, 180c may be configured to communicate with the WTRUs 102a, 102b, 102c in a standalone configuration and / or a non-standalone configuration. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c without accessing other RANs (e.g., eNode-Bs 160a, 160b, 160c, etc.). In a standalone configuration, the WTRUs 102a, 102b, 102c may utilize one or more of the gNBs 180a, 180b, 180c as mobility anchor points. In a standalone configuration, the WTRUs 102a, 102b, 102c may communicate with the gNBs 180a, 180b, 180c using signals in unlicensed bands. In a non-standalone configuration, the WTRUs 102a, 102b, 102c may communicate / connect to a gNB 180a, 180b, 180c while also communicating / connecting to another RAN, such as an eNode-B 160a, 160b, 160c. For example, the WTRUs 102a, 102b, 102c may implement the DC principle to communicate with one or more gNBs 180a, 180b, 180c and one or more eNode-Bs 160a, 160b, 160c substantially simultaneously. In a non-standalone configuration, the eNode-Bs 160a, 160b, 160c may act as mobility anchors for the WTRUs 102a, 102b, 102c, and the gNBs 180a, 180b, 180c may provide additional coverage and / or throughput for serving the WTRUs 102a, 102b, 102c.

[0052] Each of the gNBs 180a, 180b, 180c may be associated with a particular cell (not shown) and may be configured to handle radio resource management decisions, handover decisions, scheduling of users in the UL and / or DL, support for network slicing, dual connectivity, interworking between NR and E-UTRA, routing of user plane data to user plane functions (UPFs) 184a, 184b, routing of control plane information to access and mobility management functions (AMFs) 182a, 182b, etc. As shown in FIG. 1D, the gNBs 180a, 180b, 180c may communicate with each other via an Xn interface.

[0053] 1D may include at least one AMF 182a, 182b, at least one UPF 184a, 184b, at least one Session Management Function (SMF) 183a, 183b, and possibly a Data Network (DN) 185a, 185b. Although each of the above elements is shown as part of the CN 115, it will be understood that any of these elements may be owned and / or operated by an entity other than the CN operator.

[0054] The AMF 182a, 182b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N2 interface and may act as a control node. For example, the AMF 182a, 182b may be responsible for authenticating users of the WTRUs 102a, 102b, 102c, supporting network slicing (e.g., handling separate PDU sessions with separate requirements), selecting a particular SMF 183a, 183b, managing registration areas, terminating NAS signaling, mobility management, etc. Network slicing may be used by the AMF 182a, 182b to customize CN support for the WTRUs 102a, 102b, 102c based on the type of service being utilized by the WTRUs 102a, 102b, 102c. For example, separate network slices may be established for separate use cases such as services relying on Ultra-Reliable Low Latency (URLLC) access, services relying on Enhanced Large Capacity Mobile Broadband (eMBB) access, services relating to Machine Type Communications (MTC) access, etc. The AMF 162 may provide a control plane function for switching between the RAN 113 and other RANs (not shown) employing other radio technologies such as LTE, LTE-A, LTE-A Pro, and / or non-3GPP access technologies such as WiFi.

[0055] The SMFs 183a, 183b may be connected to the AMFs 182a, 182b in the CN 115 via an N11 interface. The SMFs 183a, 183b may also be connected to the UPFs 184a, 184b in the CN 115 via an N4 interface. The SMFs 183a, 183b may select and control the UPFs 184a, 184b, and configure the routing of traffic through the UPFs 184a, 184b. The SMFs 183a, 183b may perform other functions, such as managing and assigning UE IP addresses, managing PDU sessions, controlling policy enforcement and QoS, providing downlink data notification, etc. The PDU session type may be IP-based, non-IP-based, Ethernet-based, etc.

[0056] The UPFs 184a, 184b may be connected to one or more of the gNBs 180a, 180b, 180c in the RAN 113 via an N3 interface, which may provide the WTRUs 102a, 102b, 102c with access to packet-switched networks, such as the Internet 110, to facilitate communications between the WTRUs 102a, 102b, 102c and IP-enabled devices. The UPFs 184, 184b may perform other functions, such as routing and forwarding packets, enforcing user plane policies, supporting multi-homed PDU sessions, handling user plane QoS, buffering downlink packets, providing mobility anchoring, etc.

[0057] The CN 115 may facilitate communication with other networks. For example, the CN 115 may include or communicate with an IP gateway (e.g., an IP Multimedia Subsystem (IMS) server) that serves as an interface between the CN 115 and the PSTN 108. The CN 115 may provide the WTRUs 102a, 102b, 102c with access to other networks 112, which may include other wired and / or wireless networks owned and / or operated by other service providers. In one embodiment, the WTRUs 102a, 102b, 102c may be connected to local data networks (DNs) 185a, 185b through UPFs 184a, 184b via an N3 interface to the UPFs 184a, 184b and an N6 interface between the UPFs 184a, 184b and the DNs 185a, 185b.

[0058] 1A-1D and corresponding descriptions thereof, one or more or all of the functions described herein in connection with one or more of the WTRUs 102a-d, base stations 114a-b, eNode-Bs 160a-c, MME 162, SGW 164, PGW 166, gNBs 180a-c, AMFs 182a-ab, UPFs 184a-b, SMFs 183a-b, DNs 185a-b, and / or any other devices described herein may be performed by one or more emulation devices (not shown). The emulation devices may be one or more devices configured to emulate one or more or all of the functions described herein. For example, the emulation devices may be used to test other devices and / or to simulate network and / or WTRU functions.

[0059] The emulation device may be designed to perform one or more tests of other devices in a lab environment and / or in an operator network environment. For example, the one or more emulation devices may perform one or more or all functions while being fully or partially implemented and / or deployed as part of a wired and / or wireless communication network to test other devices in the network. The one or more emulation devices may perform one or more or all functions while being temporarily implemented / deployed as part of a wired and / or wireless communication network. The emulation device may be directly coupled to another device for testing purposes and / or may perform testing using over-the-air wireless communications.

[0060] The one or more emulation devices may perform one or more functions, including all functions, while not implemented / deployed as part of a wired and / or wireless communication network. For example, the emulation devices may be utilized in a testing laboratory and / or testing scenario in a non-deployed (e.g., testing) wired and / or wireless communication network to perform testing of one or more components. The one or more emulation devices may be test equipment. Direct RF coupling and / or wireless communication via RF circuitry (which may include, for example, one or more antennas) may be used to transmit and / or receive data by the emulation devices.

[0061] Referring to Figure 2, a diagram illustrating various approaches for connecting multiple devices to the Internet is shown. As shown, the devices may be connected to the Internet through one or more access technologies, including but not limited to a wireless personal area network / local area network (PAN / LAN), a wireless wide area network (WAN), a low power WAN, or other technologies.

[0062] Energy efficiency may be a key requirement for these devices. For example, in IoT applications, it may be desirable to maximize the battery life of the device. Table 1 shows several conventional approaches to reducing device cost and complexity, as well as reducing device power consumption in IoT applications.

[0063] [Table 1]

[0064] Two energy-efficient techniques developed in LTE include Power Save Mode (PSM), introduced in Release 12, and Enhanced DRX (eDRX) cycle, introduced in Release 13. While PSM can significantly extend the battery life of a device, a disadvantage of the PSM technique is that the respective device is not reachable while in PSM mode. In DRX mode, the device powers down most of its circuitry (e.g., RF transceiver, modem, application processor, etc.) when there are no packets to be transmitted or received. A slow reference clock and a minimal amount of circuitry are kept active, allowing the WTRU to periodically wake up and listen to the downlink for pages. This type of scheduled approach is commonly known as duty cycling.

[0065] Referring to FIG. 3, a diagram illustrating PSM is shown. When operating in PSM, the WTRU may be registered with the network, but the WTRU may be considered switched off and power consumption may be minimal since it may be in a deep sleep state while in this state. PSM may target mobile initiated use cases in which the WTRU may wake up from PSM if it has data to transmit. When the WTRU wakes up from PSM, it may perform a Tracking Area Update (TAU) and may remain reachable only for a short duration (in idle state) before it goes back to sleep. This process is illustrated in FIG. 3, where the WTRU is in a dormant period with very low power output. Tx activity may result in a power spike, followed by a paging time window, followed by a return to the dormant period. Thus, in PSM mode, the network may not be able to reach the WTRU at a time of its choosing. Because the WTRU can only be in receive mode for a short period of time. There may be two periods for a WTRU in PSM to negotiate with the network. When the WTRU performs a "connection request" or a "TAU request", the WTRU may include the following information elements (IEs): T3324 for monitoring paging, and T3412 for extended periodic TAU updates (i.e., an inactivity timer, denoted as dormancy period). If the network supports PSM, it may provide the resulting values ​​of T3324 and T3412 in a "connection accept" or a "TAU accept". After expiration of T3412, the WTRU may perform the TAU procedure.

[0066] Referring to FIG. 4, a diagram illustrating a DRX cycle is shown. eDRX may be more suitable for mobile terminated scenarios. In DRX / eDRX, the WTRU may not generate unnecessary signaling, such as the TAU procedure in PSM mode. However, the WTRU may need to wake up during the duration of a paging transmission window (PTW) to monitor the control channel. The frequency of waking up during the duration of the PTW may determine the efficiency of eDRX. For example, eDRX may be configured for as long as 43.69 minutes in idle mode, while for connected mode it may be 10.24 seconds. For DRX, the maximum time period may be 2.56 seconds. The difference between eDRX and DRX may be large due to the actual power allocated during the DRX / eDRX cycle as well as the duration the device circuitry is switched off.

[0067] In legacy DRX, the power of the circuit is P sleep can be held at P sleep is the power P used when the device is in eDRX deep_sleep However, the required T to move from eDRX to PTW (or vice versa) prepare There may be a ramp-up / ramp-down time of 100 ms. Because of the latency involved in switching between PTW and eDRX, there may be a need for a longer duration of the eDRX cycle. To fully utilize the power savings in deep sleep state, the duration of the eDRX cycle may be large while the duration of the PTW may be small. However, this may increase the latency in reaching the WTRU. Therefore, the optimal values ​​of the PTW and eDRX duration may need to be designed based on a trade-off between latency and power.

[0068] Referring to FIG. 5, a diagram illustrating a PSM that may be used in a conventional IEEE 802.11 system to help stations conserve power is shown. When entering a doze (or sleep) state, a station (STA) may send a NULL frame with the power management bit set to 1 and then enter the doze state. The AP may buffer packets addressed to the STA in the PSM. The AP may inform stations in the PSM (e.g., in its beacon message) that it has buffered packets through a Traffic Information Map (TIM) information element.

[0069] STAs in the PSM can read this information from the beacon. To initiate this step, the STA may need to wake up every beacon interval, which may be approximately 102 microseconds. Alternatively, the STA can wake up at multiples of the beacon time period. This can occur when a buffered broadcast / multicast packet is to be delivered to the STA (in the PSM), through which the AP indicates to the STA, through a Delivery TIM (DTIM), that this will occur at multiples of the beacon time period. The DTIM can also be part of the beacon frame. However, the DTIM can be provided once across multiple beacons, indicating that the frame following the DTIM has broadcast / multicast data.

[0070] To retrieve the buffered packets, the STA can send a power save poll (PS-POLL) to the AP requesting the AP to send the buffered packets. The AP can send the buffered packets to the STA with the More Data bit set to 1, allowing the STA to stay in the awake state until it has received all the buffered packets. If the More Data bit is set to 0, the STA can return to the doze state.

[0071] The process outlined above may require that for every frame buffered by the AP, a STA needs to send a PS-POLL to get that frame. Also, if there are several STAs, and if the AP buffers a large amount of data for several stations, there may be many PS-POLLs requested by STAs at the same moment, which may result in increased collisions.

[0072] In unscheduled automatic power save delivery mode (U-APSD), the procedure for entering the doze state may be similar to the legacy IEEE 802.11 PSM, however, a UL transmission (or a null data frame) from the STA may be taken as an indicator by the AP that the STA is awake and thereby negotiates the data transfer process, as shown in FIG.

[0073] Referring to Figure 6, a diagram illustrating Scheduled Automatic Power Save Delivery (S-APSD) is shown. In S-APSD, a STA can negotiate with an AP regarding a scheduled service interval (SSI) and the duration between consecutive SSIs. S-APSD may be suitable for cases where a traffic pattern is adhered to that is deterministic and the STA can take advantage of the deterministic pattern to save power.

[0074] Referring to FIG. 7, a diagram illustrating power saving multi-pole (PSMP) delivery is shown. PSMP is another scheduled power saving mode, in which scheduling is performed by the AP to and from multiple stations. As with the S-APSD mode, traffic patterns may need to be deterministic to leverage PSMP for power saving purposes. In a wireless network management (WNM) sleep mode, a STA may request permission to enter sleep mode. To receive traffic addressed to a group, a STA may optionally indicate the actual wake-up time in the "WNM Sleep Interval" field in the WNM sleep mode request frame.

[0075] In spatial multiplexing (SM) power save mode, a STA may operate with one receive chain throughout the entire session to conserve power (also referred to as static SM power save mode), or may have one receive chain active to detect data intended for reception, in which case one or more receive chains may be switched to active (e.g., dynamic SM power save mode).

[0076] Referring to FIG. 8, a diagram illustrating a device power profile in LTE DRX mode is shown. FIG. 8 can show the power profile and signaling activity of a duty cycled device. The device can be in one of two modes: active or sleep. When active, the device transmits P TX In receive mode, P RX When in sleep mode, the device power can be calculated by consuming the leakage power P LEAK The battery life of a device may depend primarily on how often the unit transmits and the size of the battery.

[0077] 9A-9B, diagrams illustrating battery life of an MTC device with different paging cycles are shown. Fig. 9A shows a 20-year battery life achieved with a leakage power of 12 μW and a paging cycle of 30 hours. Fig. 9B shows a 30-year battery life achieved with a leakage power of 8 μW and a paging cycle of 45 hours.

[0078] Depending on the transaction cycle of the WTRU (i.e., the average frequency at which the WTRU transmits data to the network), duty cycling has been shown to extend the battery life of, for example, an MTC device by approximately four years. The results summarized in FIG. 9A-9B may be for an example device located at the cell edge and powered by two (e.g., 1.2V and 2.1A) lithium AA batteries. As shown in FIG. 9A, the leakage power of the device in sleep mode may be assumed to be 12 μW. The battery life of an MTC device that transmits data infrequently (e.g., with a transaction cycle of one hour or more) may be limited by the paging cycle. The maximum battery life for a paging cycle of 2.56 seconds may be approximately one year. If the paging cycle is extended to 10.24 seconds, the maximum achievable battery life may be approximately four years.

[0079] 9A also shows that a very long paging cycle and about 30 hours of transaction cycles may be required to achieve a 20-year battery life using scheduled network paging. In this example, the device's battery life may be limited by the power wasted in the slow reference clock and the leakage current of various active electronic components in the device. Thus, an LTE MTC device in DRX mode can only receive at most one page every 30 hours and send data back to the network at most once every 30 hours to achieve a 20-year battery life.

[0080] 9B shows that 45 hours of paging and transaction cycles may be required to achieve a 30-year battery life if the leakage power is assumed to be 8 μW, which may result in very long latency that may not be suitable for many existing and emerging applications.

[0081] SigFox™ and LoRa™ are examples of unique low power and long range IoT solutions. If the number of transmissions is limited, the battery life of a SigFox™ module can be very long. If the unit is used to transmit very infrequent alarms, only one keep-alive message per day is sent, and one command message per day is received, the battery life can be more than 10 years using three (e.g., 1.2V and 2.1A) lithium AA batteries. The life can be 6 years with 10 transmissions per day using three (e.g., 1.2V and 2.1A) lithium AA batteries. LoRa™ devices can achieve similar battery life for the SigFox™ operating conditions described above.

[0082] While duty cycling can extend the battery life of the WTRU, there may be an inherent energy / latency tradeoff associated with this type of approach. Making the paging cycle longer while reducing the energy consumption of the WTRU may result in longer latency (i.e., the delay from when an entity connected to the network generates a packet for the WTRU to when the WTRU wakes up and is ready to receive the packet and respond with data). Alternatively, if the paging cycle is shortened to reduce latency, this in turn may shorten the battery life of the WTRU.

[0083] There may be many cases where it is desirable to deploy battery-operated devices for 20 years or more. Servicing these devices frequently to recharge or replace the battery may be infeasible or impossible. Furthermore, the average transaction cycle of these devices may be very long, yet an on-demand (low latency) paging mechanism may be necessary. Thus, new paging approaches that can overcome the energy / latency tradeoff associated with duty cycling are desirable.

[0084] A wake-up signal sequence is disclosed that includes a power-optimized waveform for wireless power delivery and a wake-up command employing a unique energy signature. Broadcast, multicast, or unicast wake-up commands employing a unique energy signature are provided, where the unique energy signature can be constructed employing principles of stored energy threshold event stacking, stored energy quantization, and / or stored energy threshold event separation encoding.

[0085] The end-to-end system employed by the disclosed paging procedures may include an asset management entity, a core network and the Internet, one or more eNodeBs (eNBs) or access points, one or more facilitators, one or more devices, and a zero energy RAN interface.

[0086] 10A-10B, diagrams of the top-level architecture of a facilitator and an interrogator are shown. The top-level architecture of a facilitator may include a primary transceiver (TRX), a processor unit, and an interrogator. The primary transceiver may be used to form one or more wireless interfaces (e.g., Uu and PC5) with base stations, other facilitators, and devices.

[0087] The interrogator is used to form a zero energy interface with a device equipped with a passive transceiver. The interrogator may include a transmitter, a receiver, a carrier compensation unit (CCU), a frequency / time reference unit (FTRU), and a processor. The transmitter and receiver in the interrogator may use a circulator to access the antenna. The interrogator may transmit a sinusoidal pulse and examine the backscattered version of this pulse with its receiver. The CCU may be used for self-interference cancellation. The CCU may cancel the portion of the transmitted signal that leaks to the receiver due to the finite separation between the transmitter and receiver in the interrogator. The interrogator may examine a pseudorandom modulated or clipped sinusoid backscattered from a passive device to determine the frequency error of the oscillator in the passive device.

[0088] Referring to Figure 11, a top level radio architecture of a battery powered device is shown. The battery powered device may include one or more primary active transceivers, one or more passive transceivers, a microcontroller unit and memory, a frequency reference unit (FRU) and a time reference unit (TRU), a power management unit, and a battery.

[0089] Referring to FIG. 12, a diagram showing a top-level depiction of a multi-mode / multi-band device is shown. A multi-mode / multi-band device may include a multi-band (n frequency bands) cellular transceiver, several (m) low-power short-range (e.g., IEEE 802.11, Bluetooth, ZigBee, etc.) transceivers, and / or a multi-input passive transceiver. The passive transceiver may conform to existing standards such as Near Field Communication (NFC), Radio Frequency Identification (RFID), or it may be a proprietary solution. In sleep mode, the device may shut down its cellular and low-power transceivers. Alternatively, some or all of the low-power transceivers may remain active while the cellular transceiver is shut down in sleep mode.

[0090] Referring to FIG. 13A, a diagram illustrating an FDD device with a single-band passive transceiver that can benefit from the disclosed paging procedure is shown. The FDD device may include a duplexer. The receive output of the duplexer can be split into two by a switch. One of the switch outputs can be connected to an active receiver, while the other switch output can be connected to a passive transceiver. In a sleep mode, the switch output can be left in position b and the active transceiver can be shut down.

[0091] Referring to FIG. 13B, a diagram is shown illustrating an FDD device with a dual band passive transceiver that can benefit from the disclosed paging procedure. The dual band passive transceiver can be integrated into an RF front end. The FDD device can include a duplexer. In this example, both of the duplexer outputs can be split into two by a switch. In a sleep mode, switch 1 can be left in position "a" and switch 2 can be left in position "b", while the active transceiver can be shut down.

[0092] A similar example of a single band half-duplex FDD (HD-FDD) mode device that can benefit from the proposed paging procedure is shown in Figures 14A-B.

[0093] Referring to Figure 14A, a HD-FF device with a single-band passive transceiver is shown. In sleep mode, both switch 1 and switch 2 outputs can be left in position "b", while the active transceiver can be shut down.

[0094] 14B, an HD-FF device with a dual-band passive transceiver integrated in the RF front end is shown. In sleep mode, the output of switch 1 can be left in either position, the output of switch 2 can be in position "a", the output of switch 3 can be in position "b", while the active transceiver can be shut down.

[0095] 15, a diagram illustrating a single band TDD mode device that can benefit from the disclosed paging procedures is shown. In sleep mode, the outputs of Switch 1 and Switch 2 can be left in position "b" while the active transceiver can be shut down.

[0096] Referring to Figure 16A, a diagram is shown illustrating a dual-band FDD device that can benefit from the disclosed paging procedure. Figure 16A shows a dual-band FDD device that integrates a dual-band passive transceiver into the FDD receive path. It should be noted that a quad-band passive transceiver can be integrated into the device shown in Figure 16A by employing the method described above.

[0097] Referring to Figure 16B, a diagram is shown illustrating a single-band FDD device that can benefit from the disclosed paging procedure. Figure 16B shows a single-band transmitter with dual-band downlink carrier aggregation. In other words, Figure 16B shows an FDD device capable of inter-band downlink carrier aggregation. It should be noted that although a dual-band passive transceiver is shown in Figure 16B, a tri-band passive transceiver can be integrated into the device shown in Figure 16B by employing the above-mentioned method.

[0098] The above-described approaches are not radio access technology (RAT) specific: they may be applied to devices employing cellular, 802.11, Bluetooth, ZigBee, or any other RAT that employs an active transceiver.

[0099] Referring to FIG. 17, a top-level architecture of a passive receiver (P-RX) is shown. The P-RX may include a single-input or multi-input passive front-end, a single-input or multi-input Analog to Information (A / I) converter, and a single-input or multi-input command interpreter. The passive front-end may include a set of design parameters {n, ζ}. The parameter n may be used to set the passive gain of the front-end. The parameter ζ may be used to set the RC time constant. The A / I converter based on stored energy thresholding may include multiple voltage-to-pulse (V / P) converters. The A / I converter may include k inputs and k parameters {V TH1 ...V THk}. The output of the A / I converter can be used by a command interpreter. The "success criteria" of the command interpreter is the set of parameters {N 1 ...N k}. The set of input signals to the command interpreter can be defined by 1 ...P k} meets the success criteria defined by its parameter set, the command interpreter may then generate an interrupt Y.

[0100] Referring to Figures 18A-B, diagrams illustrating passive front-end implementations are shown. Figure 18A shows a simplified overview of a single-ended architecture. Figure 18B shows a simplified overview of a differential or balanced architecture. Each implementation may employ a transformer with a turns ratio of 1:n. The turns ratio of the transformer may be optimized to provide passive gain and matching with the input. A single diode (D1) or a pair of diodes (D1, D2) may be used to rectify the input signal r(t). A capacitor C may be used as an auxiliary energy storage element. SUPPResistors R1 and R2 may be used to ensure proper impedance at the input port of the transformer T1. The resistors R1 and R2 are connected to the capacitor C SUPP Together, they define the time constant ζ of the passive front-end. The parameter set {n, ζ} can allow for the selection of the effective sensitivity level and reaction time of the passive front-end.

[0101] 19A-19B, diagrams illustrating a possible set of input and output waveforms for a passive front end are shown. FE The passive front end SUPP FIG. 19A shows the output waveform V in response to a continuously present sinusoidal input r(t). FE The output V FE is the desired threshold voltage level V for a given input signal r(t). TH The time required to reach TH ) is C SUPP It can be controlled by appropriately selecting the value of C. SUPP is the threshold voltage V TH With respect to t, the larger TH FIG. 19B shows the response of the passive front end to a pulsed sine wave. SUPP If (and associated circuitry) does not exhibit substantial losses, the output V FE is the desired threshold voltage V in response to a pulsed sine wave. TH If an input r(t) is present, then the output voltage V FE can rise proportionally to the amplitude of the input signal. When no input is present, V FE can be held close to a constant value until the input is seen again.

[0102] Referring to FIG. 20A, a diagram illustrating an embodiment of an analog-to-information (A / I) converter is shown. The A / I converter includes a storage element C SUPP a comparator with hysteresis and a shunt switch at the input of the comparator controlled by the comparator output logic level.

[0103] Referring to FIG. 20B, a diagram showing the input and output waveforms of the A / I converter is shown. The input voltage V on the positive terminal of the comparator FE is the threshold voltage V on the negative terminal of the comparator. TH If the hysteresis amount is exceeded, the output of the comparator (P) is allowed to transition from logic low to logic high. This closes the shunt switch connected to the positive input terminal of the comparator, thereby charging the storage capacitor C SUPP Empty and V FE V TH The input voltage can be reduced to below V TH The amount by which the voltage at its input is reduced below V can also be set to the comparator hysteresis. As a result, the comparator operates when the voltage at its input is reduced below V TH A pulse can be generated at its output each time the comparator exceeds the threshold voltage Vcc. The width of the generated pulse can be set by the hysteresis voltage of the comparator.

[0104] Referring to FIG. 21, a diagram showing an A / I converter with an automatic sensitivity control mechanism is shown. The comparator threshold voltage V TH teeth, VFE and V REF It is possible that the superposition of SUPP Voltage V across FE When is large, V REF The portion of this voltage applied to V can increase the trip point of the comparator, thereby reducing the sensitivity of the A / I converter. FE When is small, V TH Basically, V REF, thereby increasing the sensitivity of the A / I converter.

[0105] 22A-22B, an alternative example of an A / I converter is shown. FIG. 22A shows a single-ended implementation. It is first assumed that the output of the comparator (P) is in a logic low state, so that switch S1 can be closed and switch S2 can be opened. The input voltage V FE is the threshold voltage V TH When the voltage Vcc exceeds the threshold voltage Vcc, the output P can transition from logic low to logic high, thereby opening switch S1 and closing switch S2. In contrast to the embodiment shown above, the auxiliary storage element C SUPP The energy stored in the primary storage element C PRIM can be forwarded to C PRIM is C SUPP It is possible to achieve much more than C PRIM The voltage above is V TH If the voltage at the positive terminal of the comparator is less than V TH , thereby returning the output P to a logic low. Figure 22B shows a fully differential or balanced implementation of this type of A / I converter.

[0106] Referring to FIG. 23, a diagram showing an alternative embodiment of an A / I converter is shown. The voltage V FE is the number of k different threshold voltages (V TH1 , V TH2 ,...V THk ) can be quantized to k levels using k comparators. The A / I converter has k outputs (P 1 , P 2 , ...P k ) to generate V FE It is possible to estimate

[0107] Referring to FIG. 24, a diagram showing another overview of a P-RX is shown. The P-RX may include one or more inputs (e.g., a k-input P-RX). The P-RX may include k passive front-ends and k A / I converters. One or more diode rectifiers in the k passive front-ends are connected together with a single storage capacitor C SUPP It is possible to drive a single V / P converter in the message decoder.

[0108] Referring to Figure 25, a diagram of a passive transceiver (P-TRX) is shown. The P-TRX may include single or multiple antennas, a multiplexer, single to multiple passive receivers, single or multiple load banks, a controller and digital to analog converter (CU&D / A) unit, a frequency / time base unit (FTRU), and / or single or multiple modulating waveform generators.

[0109] An m / N multiplexer (MUX) has m inputs (x 1 ...x m ), N outputs (y 1 ...y N), and a control port C. The control port C may be used to connect the m inputs of the MUX to m of the N outputs of the MUX. The P-TRX may receive an unmodulated sine wave on one or more antennas. In response, the passive receiver may generate an interrupt to the CU&D / A unit indicating that an RF field is being sensed. The passive receiver may employ a stored energy thresholding principle to generate the interrupt. In response, the CU&D / A may activate the FTRU, which may activate a clock signal and send the clock signal to the load modulation waveform generator (LMWFG). The passive receiver may generate a second interrupt to activate the load modulation waveform generator (LMWFG). When the LMWFG receives the activation signal from the passive receiver and the clock from the FTRU unit, the LMWFG may apply a modulated waveform to the control port C of the MUX, thereby connecting the antennas to separate loads in the load bank. It is capable of amplitude modulating the sine wave backscattered from the P-TRX. The LMWFG can generate sine waves, square waves, pseudorandom sequences, or chirp sequences to create a variety of backscatter patterns.

[0110] Referring to FIG. 26A-B, a diagram showing a pulse counting wake-up command interpreter is shown. FIG. 26A shows a stored energy thresholding event counting wake-up command interpreter (ET-CI) for a single-input RT-WURX. FIG. 26B shows a stored ET-CI for a multi-input RT-WURX. The ET-CI may include a counter and a combinational logic block. The combinational logic block may perform a comparison between its two inputs C[m:0] and N. If the (m+1)-bit counter output C[m:0] reaches a count equal to N, the combinational logic block may set its output Y to logic high.

[0111] Referring to Figures 27A-B, diagrams illustrating the operation of a single input ET-CI are shown. Figure 27A shows an ET-CI configured for two threshold events from the A / I converter. When N=2 consecutive pulses are detected at the output of the A / I, the ET-CI can transition its output Y from logic low to logic high, thereby generating an interrupt. Figure 27B shows an ET-CI configured for three threshold events. When N=3 consecutive pulses are detected at the output of the A / I, the ET-CI can transition its output Y from logic low to logic high, thereby generating an interrupt.

[0112] To optimize the detection and false alarm probability of the RT-WURX, the A / I converter threshold voltage (V TH ) and a target number of events (N) for the threshold event counter may be used. For example, V TH Setting both,N,and,N,to high values ​​will make the RT-WURX robust to noise,,and thereby reduce false alarms.,However, more energy will be required to trigger a wake-up,interrupt with such a configuration.

[0113] A stored energy quantization wake-up command interpreter can examine the digital bit sequence, which can be generated by an analog-to-information converter in the passive receiver front-end, and can generate an interrupt if the bit sequence received from the passive receiver front-end matches a predefined code.

[0114] 28A-C, diagrams of the stored energy threshold event isolation decoding wake-up command interpreter (ETESD-CI) for single-input and multi-input RT-WURX are shown. The ETESD-CI may include two main blocks: a pulse isolation decoding (PSD) data detector and decision logic. The PSD data detector is shown in FIG. 28A. The single-input ETESD-CI is shown in FIG. 28B, and the three-input ETESD-CI is shown in FIG. 28C.

[0115] The PSD data detector shown in Figure 28A may include a counter and a multi-bit latch. The counter clock (CLK) frequency may be set significantly (e.g., 10 times) higher than the minimum expected separation between successive pulses P from the analog-to-information converter. The pulse P may be used to store the counter value in the latch and then reset the counter. The successive outputs W of the latch provide a scaled numerical measure of the time separation between successive incoming pulses P. This information may be used by the data detector.

[0116] The data detector includes two programmable parameters C0 and C1. According to an embodiment, the operation principle of the data detector is described in Equation 1. The decision logic block may have one programmable parameter N. Its output may be initialized to logic low and may transition to logic high if the output bit pattern X of the PSD data detector matches N.

[0117]

number

[0118] Referring to FIG. 29, a diagram illustrating the operation of a single-input ETESD-CI is shown. th , and P are associated with the wake-up receiver's passive front-end and A / I converter. Signals X and Y are associated with the ETESD command interpreter.

[0119] The ETESD-CI may require a start sequence (e.g., 111) to begin the wake-up command interpretation process. Once the start sequence is detected, the measured time separation between successive pulses P may be used to decode the data. If the measured separation between successive pulses P is less than C1, it may be interpreted as a binary bit of value 1. If the measured separation between successive pulses P is greater than C0, it may be interpreted as a binary bit of value 0. When the programmed bit pattern N (e.g., 01100) is received by the decision logic block, its output may transition from logic low to logic high, thereby generating an interrupt.

[0120] Referring to Figure 30, a diagram showing the resource cube used to construct the wake-up word is shown. The network can employ all or a subset of the elements in the resource cube (angle, frequency, time) to construct the wake-up signal sequence. The wake-up signal sequence may include a power-optimized waveform and a wake-up command employing a unique energy signature.

[0121] The frequency resources may include a mix of carriers and subcarriers. The carriers can be included in a single frequency band or in multiple frequency bands. The network can employ one or more unmodulated carriers or conventional carrier modulation techniques, such as on / off keying (OOK), binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), quadrature amplitude modulation (QAM), etc., to transmit the wake-up command. Unique energy signature methods such as stored energy quantization (SEQ), stored energy threshold event stacking (SET), or stored energy threshold event separation encoding (SETES) schemes can also be used to transmit the wake-up command. One or more methods can be combined to create a hybrid method for transmitting the wake-up command.

[0122] The network can generate broadcast, multicast or unicast wake-up commands to wake up all devices, groups of devices or individual devices in a coverage area. Multiple base stations can be directed to cooperate in sending wake-up commands.

[0123] A broadcast wake-up command can be constructed with single or multi-frequency SEQ, SET, or SETES commands. Multiple SEQ, SET, and SETES commands can be combined to create a composite wake-up command. All devices in a coverage area can be programmed to respond to the same simple or composite wake-up command, and the wake-up command can be sent in an omnidirectional manner to wake up all devices in the coverage area. According to an embodiment, the network can be partitioned into several spatial sectors, and the same broadcast command can be sent in each angular direction using beamforming.

[0124] A multicast wake-up command can be constructed with single or multi-frequency SEQ, SET, or SETES commands. Multiple SEQ, SET, and SETES commands can be combined to create a composite wake-up command. A network can be partitioned into spatial sectors, and the same command can be sent in a specific sector or a subset of sectors to wake up separate groups of devices. Alternatively, a multicast wake-up command can include a preamble and a body. The preamble can be a group identifier, and the body can be a wake-up command for all devices in the coverage area. The preamble can be constructed using a SEQ or SET command, and the body can be constructed using a SETES command.

[0125] A unicast wake-up command can be constructed with single or multi-frequency SEQ, SET, or SETES commands. Multiple SEQ, SET, and SETES commands can be combined to create a composite wake-up command. A network can be partitioned into several spatial sectors, and each sector can include only one device. The same command can be sent in a specific sector to wake up a specific device. Alternatively, a unicast wake-up command can include a preamble and a body. The preamble can be a group identifier, and the body can be a wake-up command for a specific device in the group. The preamble can be constructed using a SEQ or SET command, and the body can be constructed using a SETES command.

[0126] Referring to Figure 31, a diagram illustrating a transmitter structure that may be used to generate a wake-up command is shown. A modulation generator may be used to map the wake-up command bits onto OFDM subcarriers that may be designated for use by the wake-up command. The modulation generator may employ a scaled superposition of the designated subcarriers to achieve a wake-up signal with desired time-domain properties.

[0127] Referring to FIG. 32A to FIG. 32D, a single frequency resource (f 1 ) and a diagram showing a wake-up word utilizing up to L=9 time resources is shown. The strength of the word employing L time resources can range from 1 / L to 1. FIG. 32A shows a wake-up word of strength f 1 This shows the symbolic representation of the word (3 / 9,f 1 ) word. 1The time domain waveform underlying the (1,f1) wake-up word is shown in Figure 32C. Figures 32B and 32D show the (1,f1) wake-up word.

[0128] Referring to FIG. 33A to FIG. 33B, (3 / 9,f 1 A diagram illustrating an implementation of a wake-up word is shown in FIG. 1. The time resources in the wake-up word do not have to be contiguously located.

[0129] 34A-34B, diagrams illustrating wake-up words utilizing multiple frequency and time resources are shown. FIG. 34A illustrates a word employing a combination of (3 / 9, f1) and (1, fk) frequency / time resources. This may be referred to as a {(3 / 9, f1), (1, fk)} word. FIG. 34B illustrates a {(3 / 9, f1), (4 / 9, f2), (1, fk)} word.

[0130] 35A-35B, a diagram illustrating a wake-up word utilizing j angular resources, k frequency resources, and up to L time resources is shown. FIG. 35A illustrates a wake-up word utilizing two different angular resources θ 1 and θ 2 The same combination of time and frequency resources (3 / 9,f 1 ) and (1,f 2 ) is used. This is the word that uses [{θ 1 ,(3 / 9,f 1 )},{θ 2 ,(1,f 2 )}] word. 1 ,(3 / 5,f 1 )},{θ 2 ,(4 / 9,f 1 ),(1,f 2 )}] word.

[0131] Referring to FIG. 36A-B, a diagram illustrating an (L,m,k,N) wake-up command structure is shown. A stored energy threshold event stacking wake-up command may employ a (N,m,k,L) combination of resources. The wake-up command may be constructed using N identical words employing m angle resources, k frequency resources, and L time resources per word. FIG. 36A illustrates a wake-up command employing 4 words (N=4), a single angle (m=1), a single frequency (k=1), and 5 time resources (L=5) per word. This may be referred to as a (4,1,1,5) wake-up command. FIG. 36B illustrates a (3,1,2,9) stored energy threshold event stacking wake-up command employing N=3 words, m=1 angle per word, k=2 frequency, and L=9 time resources.

[0132] The number of words N in the wake-up message may correspond to the number of threshold events required to trigger an interrupt at the target device. The number of time resources L per word may correspond to the range of energies (1 / L to 1) that may be transmitted by a base station or a combination of base stations. The duration of each time resource in a word may be a full frame or a subframe in an LTE system. The wake-up command may employ, for example, resource blocks in the LTE control plane or data plane. Words in the wake-up command may be mapped, for example, onto paging occasions in an LTE system.

[0133] A wake-up command based on the stored energy quantization may employ a (m, k, L) combination of resources. The wake-up command may employ N separate words corresponding to each of the N quantization levels, with m angular resources, k frequency resources, and L time resources used per word.

[0134] 37A-37D, a diagram illustrating a wake-up command based on stored energy quantization is shown, in which four quantization levels are implemented. Each of the four words may employ a single angle resource, a single frequency resource, and eight time resources. The lowest quantization level may be implemented using one of the eight time resources and may have a strength of 1 / 8. The time resources may be located anywhere in the word. The highest quantization level may be implemented using all eight time resources and may have a strength of 1.

[0135] Referring to FIG. 38, a diagram is shown illustrating a time domain display of a constant energy amplitude modulation waveform used to generate a stored energy threshold event isolation decoding wake-up command. The constant energy amplitude modulation waveform can be mapped to a single word or to multiple consecutive words. This example waveform can encode the binary sequence 01. The waveform can begin with a start sequence, followed by a sine wave of amplitude A0 and duration T0 used to encode a binary bit of value 0, and a sine wave of amplitude A1 and duration T1 used to encode a binary bit of value 1.

[0136] The criterion for selecting the amplitude and duration parameter pairs {Ai, Ti} to encode the binary values ​​0 and 1 is described below in Equation 2. Two sinusoids that encode the binary values ​​0 and 1 can have the same energy.

[0137]

number

[0138] For example, the desired time separation between pulses to encode a binary bit value of 0 may be three times that of a binary bit value of 1. Once an amplitude and duration pair {A1, T1} is selected that represents a binary bit value of 1, the amplitude A0 required to encode a binary bit value of 0 can be calculated by setting T0=3T1 and using Equation 2.

[0139] Described herein are networks that transmit signal sequences that include a power-optimized waveform and a broadcast, multicast, or unicast wake-up command with a unique energy signature. Also described herein are devices and techniques for receiving the broadcast, multicast, or unicast wake-up command with a passive receiver and interpreting the wake-up command by transferring charge from its temporary storage element to its battery to generate a stored energy threshold event according to the unique energy signature embedded in the wake-up command.

[0140] A network is described herein that transmits an interrogation command to determine the state of a device (e.g., its frequency offset). The interrogation command may include, for example, an unmodulated carrier. The network can determine the state of the device (e.g., frequency offset) by examining backscatter from the passive transceiver of the device modulated with a pseudo-random sequence. The network can transmit a frequency correction command accompanied by a unique energy signature. The device can receive the frequency correction command using a passive receiver, interpret the unique energy signature, and make an adjustment to its time / frequency reference unit.

[0141] Referring to Figure 39, a diagram illustrating elements of a network initiated on-demand zero energy paging system is shown, which may include one or more of an asset management entity, a core network and Internet, one or more eNBs or access points, one or more facilitators, one or more devices, and a zero energy RAN interface.

[0142] The system may utilize a single radio access technology (RAT) or multiple RATs. This includes cellular (LTE), 802.11, Bluetooth, ZigBee, NFC, RFID, etc. The facilitator may be an eNB, an access point, a remote radio head, or a WTRU. A connected appliance, a connected consumer electronic device, or any other connected device with wireless communication capabilities may also act as a facilitator. The facilitator may be stationary or capable of mobility. The zero energy RAN interface may be unidirectional (downlink) or bidirectional (uplink and downlink). The zero energy link may be achieved by transmitting a radio signal with a unique energy signature from an eNB, an access point, a facilitator, etc., and through the device by employing a passive receiver using a stored energy thresholding method to interpret the commands carried by the radio signal.

[0143] Referring to FIG. 40, a diagram illustrating an on-demand zero energy paging procedure is shown. Once deployed, the device may enter a sleep mode. The paging procedure may be triggered by a network event. For example, an asset management entity may request data from the device. The active receiver in the device may not be turned on during the on-demand zero energy paging procedure. In addition to wake-up commands, synchronization signals and UL configuration information may be received by the device using its passive receiver. Details of the proposed on-demand paging procedure are outlined below. Although provided as a list, it should be understood that the procedures may be performed in any applicable order, one or more of the outlined steps may be omitted, and one or more steps may be added to the procedure.

[0144] In step 1, the network may instruct a first eNB (eNB1) to interrupt the sleep cycle of the device. The network may specify the priority level of the interruption to be implemented. According to this example, eNB1 may be the eNodeB where the device is currently registered. eNB1 calculates the parameters of the wake-up command (e.g., waveform type, power level, duration, frequency band, etc.) based on the specified interruption level. eNB1 may determine whether it needs to cooperate with one or more further eNBs (e.g., eNB2, eNB3, etc.) or a facilitator to implement the required interruption type.

[0145] In step 2, eNB1 may configure the facilitator (e.g., sidelink). eNB1 may send parameters of the portion of the wake-up command to be implemented by the facilitator. eNB1 may receive a confirmation from the facilitator.

[0146] In step 3, eNB1 may send parameters of the portion of the wake-up command to be implemented by eNB2 and may receive a confirmation from eNB2.

[0147] In step 4, eNB1 may send parameters of the portion of the wake-up command to be implemented by eNB3 and may receive a confirmation from eNB3.

[0148] In step 5, eNB1 may send its part of the wake-up command.

[0149] In step 6, the facilitator may send its parts of the wake-up command sequentially or simultaneously.

[0150] In step 7, eNB2 may transmit its parts of the wake-up command sequentially or simultaneously.

[0151] In step 8, eNB3 may transmit its parts of the wake-up command sequentially or simultaneously.

[0152] In step 9, the facilitator can wait a predetermined amount of time and can transmit a zero energy synchronization signal. The facilitator can examine the backscattered signal from the passive transceiver of the device and can determine a frequency error of the frequency reference unit of the device. The facilitator can transmit a signal including frequency correction instructions and uplink configuration information.

[0153] In step 10, the device can interpret signals received from the eNodeB and the facilitator using its passive transceiver. The device can turn on its primary active transmitter and can send data back to the network.

[0154] 41A-B, diagrams illustrating signaling between a device, an eNodeB, and a facilitator are shown. FIG. 41A shows eNodeB and facilitator signals. FIG. 41B shows device signals. Power profiles of the eNB, facilitator, and device are also shown in FIG. 41. Signal power levels associated with the above steps are shown in FIG. 41 using the same numerical designations.

[0155] Referring to FIG. 42, a diagram illustrating a hybrid paging procedure is shown. The network can perform an on-demand adaptation, driven by an over-the-air interrupt, of the device's (e.g., DRX mode) duty cycle period for provision of high priority paging. The device can receive DRX cycle configuration information from the network. To save power, the device can program its sleep counter with a long duty cycle period based on the DRX cycle configuration information received from the network. The device can then enter a sleep mode. In normal operation, the network can only page the device on agreed paging occasions defined by the paging cycle. The device's sleep counter can be synchronized with the network's counter, and the device can only wake up to decode paging messages during the programmed paging occasions.

[0156] The paging cycle adaptation procedure can be triggered by a network event. For example, an asset management entity may request data from the device. The asset management entity may indicate a priority level or a quality of service level. If the requested priority level is set high, the network calculates the time (delay) remaining until the next paging opportunity. If the calculated delay meets the required level of service, the network may wait to page the device until the next scheduled paging opportunity. If the calculated delay does not meet the required level of service, the network may initiate a paging cycle adaptation procedure. Details of such a paging cycle period adaptation procedure are outlined below.

[0157] Although provided as a list, it should be understood that these procedures may be performed in any applicable order, that one or more of the outlined steps may be omitted, and that one or more steps may be added to the procedure.

[0158] In step 1, the network may instruct a first eNodeB (eNB1) to interrupt the sleep cycle of the device. The network may specify a priority level of the interrupt to be implemented. eNB1 may be the eNodeB where the device is currently registered. eNB1 may calculate the parameters (e.g., waveform type, power level, duration, frequency band, etc.) of the required over-the-air (OTA) interrupt signal based on the specified interrupt level. eNB1 may determine whether it needs to cooperate with one or more eNodeBs (e.g., eNB2 and eNB3) to implement the required interrupt type.

[0159] In step 2, eNB1 may send parameters of the portion of the OTA interrupt signal to be implemented by eNB2 and may receive a confirmation from eNB2.

[0160] In step 3, eNB1 may send parameters of the portion of the OTA interrupt signal to be implemented by eNB3 and may receive a confirmation from eNB3.

[0161] In step 4, eNB1 may transmit its portion of the OTA interrupt signal. The device may receive the OTA interrupt signal using its passive receiver.

[0162] In step 5, eNB2 may transmit its parts of the OTA interrupt signal sequentially or simultaneously. The device may receive the OTA interrupt signal using its passive receiver.

[0163] In step 6, eNB3 may transmit its parts of the OTA interrupt signal sequentially or simultaneously. The device may receive the OTA interrupt signal using its passive receiver. The device may turn on its primary active receiver.

[0164] In step 7, eNB1 may wait a predetermined amount of time and may transmit a synchronization signal. The device may receive the synchronization signal using its primary active receiver.

[0165] In step 8, eNB1 may transmit the uplink configuration information. The device may receive the signal including the uplink configuration information using its primary active receiver.

[0166] In step 9, the device can turn on its primary active transmitter and transmit data back to the network.

[0167] Referring to Figures 43A-B, diagrams illustrating signaling between a device and an eNodeB are shown. Figure 43A shows the power profile and signals of the eNodeB. Figure 43B shows the power profile and signals of the device. The signal power levels associated with the numbered steps above are shown using the same numerical designations in Figure 43. Figure 43A shows the power consumption based on Tx and Rx by network components eNB1, eNB2, eNB3 associated with the steps outlined above. Figure 43B shows the power consumption based on Tx and Rx by the WTRU associated with the steps outlined above.

[0168] In implementing the OTA interrupt, the PeNB and SeNB may cooperate in a manner where the SeNB transmits an additional amount of power on the same frequency as shown in Figures 43A-B. The SeNB may also transmit portions of the OTA interrupt signal on separate carrier frequencies.

[0169] Referring to Figure 44, a diagram illustrating a zero energy wake-up procedure is shown. A device may include one or more primary active transceivers (TRX), one or more passive receivers, a power management unit (PMU), and a battery. The passive receiver may include a rectifier represented by diode D1 and resistor R1, a temporary storage element represented by capacitor C1, an analog to information A2I converter (comparator), and a wake-up command interpreter.

[0170] The network can transmit signal sequences including power optimized waveforms (POWs) and broadcast, multicast, or unicast wake-up commands with unique energy signatures. The POWs can include, for example, single-frequency or multi-frequency sinusoidal pulses. The wake-up commands with unique energy signatures can be constructed using, for example, principles of stored energy event stacking, stored energy event quantization, or stored energy event separation encoding.

[0171] The device can harvest energy from the POW and wake-up commands in the transmitted signal sequence. The harvested energy can be stored in a temporary storage element (capacitor C1). This stored energy can be used to power the A2I and wake-up command interpreter in the passive receiver of the device.

[0172] The device can receive a broadcast, multicast, or unicast wake-up command with its passive receiver and interpret the wake-up command by generating a stored energy threshold event according to a unique energy signature embedded in the wake-up command by transferring charge from its temporary storage element to its battery. The device can monitor the amount of stored energy in its temporary storage element (capacitor C1) with its A2I converter in its passive receiver. The voltage V on the temporary storage element (capacitor C1) can be calculated by the following equation: FE If the amount of stored energy or charge, denoted by FEcan be reduced below the threshold. A2I can generate a pulse P at its output every time a charge transfer occurs.

[0173] Depending on the structure of the wake-up command, this process of charge transfer can be repeated multiple times. The wake-up command interpreter can check the pulse train P, and if the pulse train matches the pattern assigned to the device by the network, it generates an interrupt Y. Upon receiving the interrupt Y, the power management unit (PMU) can generate a wake-up signal WU that is used to activate the primary transceiver (TRX) of the device. The threshold voltage V of the A2I converter TH and the pulse pattern P may be configured by the network before the device goes into sleep mode.

[0174] Range extension procedures can be employed by the network to wake up target devices that may experience significant signal quality degradation, such as devices that are far away or behind obstacles. Range extension can be achieved by beamforming and / or increasing the power and / or duration of constituent words in the wake-up command. The required power and / or duration for the device can be derived from an estimate of the path loss reported by the device before it enters sleep mode. Alternatively, the network can implement an energy ramping procedure through a set of power and duration settings. The network can implement a blind ramping procedure, whereby it goes through multiple or all power and / or duration settings. The network can also implement a ramping procedure with feedback, whereby the network waits for a preconfigured amount of time after every power and duration setting. If the device responds with a wake-up acknowledgment during this preconfigured window, the network can terminate the ramping procedure.

[0175] According to an embodiment of the disclosed subject matter, a procedure for wake-up command false alarm suppression can be implemented. A robust wake-up command can be implemented to prevent a scenario in which a device in sleep mode falsely wakes up (resulting in a false alarm) in response to ambient RF energy in the environment caused by unrelated transmissions. Employing multi-angle and multi-frequency words in constructing a wake-up command can reduce false alarms. Employing composite wake-up commands, such as a stored energy threshold event stacking command combined with a stored energy threshold event separation encoding wake-up command, can also mitigate false alarms. The device can, for example, make path loss measurements and inform the network. Based on the reported measurements, the network can determine the level of false alarm mitigation required and configure it appropriately before the device enters sleep mode.

[0176] A procedure for pseudorandom backscatter zero energy synchronization can be implemented. Frequency and timing synchronization is a procedure that reduces the frequency and timing offsets between two nodes to allow an acceptable communication link. One of the nodes or another node (e.g., a GPS signal) can be used as a reference to reduce both the frequency and timing offsets.

[0177] Procedures, methods, and apparatuses utilizing a backscatter-based zero energy wake-up verification and synchronization procedure may be described herein. It may also assist the node sending the wake-up command to determine the frequency offset of the intended or target device and to set up timing synchronization. The transmitting node (or interrogator) may determine the frequency offset by using a backscattered tone modulated with a pseudo-random sequence from the passive transceiver (TRX) of the target device. The modulated backscattered tone may reflect the primary VCO offset in the target device. The transmitting node may also send a timestamp that may determine the timing of the frame, slot, and / or symbol relative to the timing of the wake-up sequence.

[0178] The target devices can obtain their specific wake-up code or sequence as part of the initial device discovery process. Alternatively or additionally, the necessary information for the wake-up procedure, such as a unique wake-up energy signature along with other parameters for the passive TRX, can be signaled by the network and received by the target device via the active TRX before the activation of the sleep procedure. The necessary parameters, such as a pseudo-random code index, can also be sent after a common wake-up energy sequence to a specific device ID. The device ID can be assigned in advance or during the initial network attachment procedure.

[0179] Referring to Figure 45, a diagram illustrating a backscattered modulated carrier is shown. During the wake-up process, the node sending the wake-up command can estimate the initial frequency offset of the passive TRX in the target device. The interrogator receiver can utilize backscattering techniques to determine the initial frequency offset of the passive TRX in the target device, where receipt of the wake-up command with a unique energy signature can trigger the transmission of a pseudorandom (PN) code.

[0180] Referring to FIG. 46, a diagram illustrating the detection procedure is shown. When a device-specific wake-up command is detected, the passive TRX can begin generating a PN sequence that modulates a backscattered carrier. The backscattered and modulated carrier can reflect the frequency offset of the target device's Frequency / Time Reference Unit (FTRU). The FTRU can be used as a reference clock source by both the passive and active TRXs in the target device. The reference clock offset can be controlled by the FTRU.

[0181] Once the interrogator sends the wake-up command, it can begin to receive device-specific wake-up confirmation using PN code detection. The interrogator can have prior knowledge of the expected PN sequence for each device. If the interrogator successfully detects the expected PN code, the wake-up process can be confirmed as successful. During reception of the PN code, the interrogator can estimate the initial frequency offset of the passive TRX in the target device. The estimated offset can be signaled back to the passive TRX to correct the reference clock offset of the FTRU. The frequency correction procedure can utilize an open or closed loop approach and can involve multiple messages between the interrogator and the passive TRX in the target device. The interrogator can also send a time reference for the active TRX along with the estimated frequency offset.

[0182] The PN sequence detection and frequency offset estimation algorithm can utilize parallel processing units to expedite the detection and estimation process, or a single processing unit can be utilized across multiple offset settings with iterations to determine the initial frequency offset in order to make a complexity tradeoff, however, this tradeoff may increase the detection and estimation latency.

[0183] Referring to FIG. 47, a diagram showing a frequency offset estimator is shown. The method for estimating the frequency offset can employ two PN sequences (i.e., same or different sequences with same or different lengths), in which case the passive TRX can modulate the backscattered carrier with the two PN sequences. In the case of only AWGN channels, the interrogator can determine two peaks with two complex numbers for each PN sequence. As shown in FIG. 47, the frequency offset can be estimated by taking the phase difference between the two complex numbers and dividing the result by the time difference of the peak location multiplied by a normalization factor. The process can be started with the last known offset value, which can be kept in non-volatile memory.

[0184] A matched filter (MF) can be designed for the PN sequence. The output of the MF can be passed through a power converter and integrated over N iterations, where N can be from 1 to a specific number. Once the integration period is over, the maximum element and its location can be determined and compared to a threshold. If the threshold is met, the PN sequence detection can be successful. The detection process can be prone to large initial frequency offsets, so to ensure detection, artificially shifted input samples can be used at different frequency offsets with phase rotation only or with phase rotation and timing drift. This process can be performed in parallel using multiple HW units to expedite the detection process. When the detection process is completed, the peak location can be associated as the "maximum index". The sample extractor can take samples as shown in FIG. 47.

[0185] The range extension procedure may be used by an inquiring node to wake up devices that are far away or behind obstacles with significant signal quality degradation. The node can start with sending a wake-up command and set up a timer to wait for the expected response from the targeted device. If the expected response is not received by the interrogator, it can start to deploy an extended range procedure for PN sequence detection and frequency offset estimation.

[0186] If sufficient energy is harvested by the device and a device wake-up command is detected, the received tone can be continuously modulated with its predefined or network-instructed PN sequence. The device associated with the PN sequence can be known by the interrogator node before performing the PN sequence detection process. The interrogator node can accumulate the MF output after the power conversion block as shown in FIG. 46 for a period of T (where T is the length of the PN sequence) and determine the peak value and its index location (e.g., the index can vary from 0 to T-1). The peak value can be compared to a certain threshold to keep the false alarm rate below a target value. The threshold can be set differently for each round of integration periods. The integration buffer can be reset after a certain number of integrations (N). If the peak is determined to be above the threshold, detection can occur.

[0187] In the case where detection occurs only after N integrations, the interrogator can use an estimate of the frequency offset by averaging the N results and then send it to the target device with increased processing gain that can be equivalent to or better than N integrations. The device can be informed about the format as part of the initial device connection, as a factory default, and / or as a parameter provided before entering sleep mode. The interrogator can also indicate the range extension format by encoding a predefined field. The device can look for the normal mode format or the range extension mode format and decode them in parallel.

[0188] The network can transmit signal sequences consisting of power-optimized waveforms and broadcast, multicast, or unicast wake-up commands with unique energy signatures.

[0189] A device can receive a broadcast, multicast, or unicast wake-up command using a passive receiver and interpret the wake-up command by transferring charge from its temporary storage element to its battery, thereby generating a stored energy threshold event according to a unique energy signature embedded in the wake-up command.

[0190] The network can transmit an inquiry command to determine the state of the device (e.g., its frequency offset). The inquiry command can include an unmodulated carrier. The network can determine the state of the device (e.g., frequency offset) by examining backscatter from the passive transceiver of the device modulated with a pseudorandom sequence. The network can transmit a frequency correction command with a unique energy signature.

[0191] The device can receive frequency correction commands using a passive receiver, and the device can interpret the unique energy signature and make adjustments to its time / frequency reference units.

[0192] In addition to or as an alternative to standard methods for transmitting system information, the network can broadcast a tracking area update (TAU) command using a dedicated radio beacon with a unique energy signature. The TAU command can employ a frame structure including a preamble and a body. The frame body of the TAU command can include, for example, a tracking area code (TAC). The network can employ all or a subset of the elements (angle, frequency, time) in the resource cube when broadcasting the TAU command. The frequency resource can include a mix of carriers and subcarriers. The carriers can be included in a single frequency band or in multiple frequency bands. The SEQ, SET, or SETES methods can be used to construct the radio beacon. The network can also combine multiple methods to create a hybrid method when constructing the beacon used to broadcast the TAU command. The beacon can be constructed using single or multi-frequency SEQ, SET, or SETES methods. The network can broadcast the TAU command from one, several, or all eNBs in the tracking area (TA). This can be done on a regular basis or at random intervals.

[0193] In addition to or as an alternative to standard methods for accessing system information, a device can receive a TAU command with a passive receiver and interpret the unique energy signature to access system information (e.g., TAC). The device can employ stored energy quantization, stored energy threshold event counting, or stored energy threshold event separation decoding methods to interpret the unique energy signature. These methods can be used in a standalone manner or combined to create a hybrid method for interpreting the unique energy signature. A device can employ a look-up table (LUT) based approach to trigger a tracking area update (TAU) procedure. A device can store a tracking area list (TAL) in the LUT that represents its current known location. The TAL-LUT can be stored in a local memory and can be accessible while the device is in a sleep mode. A device can access system information using a passive receiver while active or while in a sleep mode. When system information (e.g., TAC) is retrieved, the retrieved TAC of the cell whose coverage area the device is currently in can be compared against the TAC in the stored TAL-LUT. If no match is found, the device can wake up if in sleep mode and perform the TAU procedure using its active transceiver. Once the TAU procedure is completed, the device can update its TAL-LUT and enter sleep mode.

[0194] Referring to FIG. 48, a diagram illustrating a cell cluster is shown. A network may deploy multiple cell clusters that broadcast a TAU command on a separate frequency to identify a tracking area (TA) boundary. The TAU command may adopt a frame structure including a preamble and a body. The preamble of the TAU command frame may include a TA boundary indicator code, and the frame body may include, for example, a tracking area code (TAC). A cell cluster may include one or more cells and may constitute part or all of a TA. The cell cluster may be centered near a TA boundary, for example, as shown in FIG. 48.

[0195] A device may identify a TA boundary crossing by detecting a change in the carrier frequency of successively received TAU commands. The device may include multiple passive receivers with TAU command interpreters preconfigured to operate on separate carrier frequencies. Each passive receiver may decode a preamble of a received TAU command and generate an interrupt if a TA boundary indicator code is decoded. The device may keep count of the number of generated interrupts, each representing a detection of a change in carrier frequency. The number of times the carrier frequency changes may be compared to a TA boundary crossing threshold. If the number of detected TA boundary crossings exceeds this threshold, the device may wake up if in sleep mode and perform a TAU procedure using its active transceiver.

[0196] A network may deploy a facilitator to enable a device to perform a zero energy TAU procedure using its passive transceiver employing indirect modulation (also known as backscatter) while remaining in a sleep mode. The facilitator may be an eNB, an access point, a remote radio head, or another device. A connected appliance, a connected consumer electronic device, or any other connected device with wireless communication capabilities may also act as a facilitator. The facilitator may be stationary or capable of mobility. The facilitator and the device may be in close proximity to each other and within the coverage area of ​​the same cell. The facilitator may have access to network system information to know the TAC of the cell to which it is currently connected. The facilitator may transmit an unmodulated carrier, and the device may include a passive transceiver employing indirect modulation (also known as backscatter) to communicate with the facilitator. The facilitator can read the TAL-LUT stored in the device and compare the TAC of the cell to which it is currently connected against the TAC in the retrieved TAL from the device. If no match is found, the facilitator can perform a TAU procedure for the device. Once the zero energy TAU procedure is completed, the facilitator can update the TAL-LUT stored in the device.

[0197] A wake-up configuration and signaling scheme may be implemented as described herein. Several WTRUs with passive wake-up transceivers may be served by an eNB. The eNB may employ a wake-up command with a unique energy signature to wake up the WTRU. The following description includes possible signaling schemes by which the eNB may configure a unique energy signature associated with a WTRU.

[0198] A group-specific energy signature may be used to wake up a particular class of WTRUs. The group-specific energy signature may be broadcast as part of a system information message (e.g., SIB-2 / SIB-3, etc.). Example signaling in SIB-2 is shown below in Table 2.

[0199] [Table 2]

[0200] Value s 1 and s 2 may be the multicast energy signature sequences allocated for waking up WTRUs belonging to class 1 and class 2, respectively.

[0201] The eNB may signal the WTRU-specific energy signal as part of the RRC message. In Table 3, the signature sequence may be signaled on the PCCH logical channel.

[0202] [Table 3]

[0203] Signature sequence e 1 may be allocated to the WTRU. If the WTRU receives a signature allocation from both a common broadcast message (e.g., a system information message) and a WTRU-specific messaging (e.g., RRC), the WTRU may use the signature allocation received by the WTRU-specific messaging.

[0204] Alternatively, the EUTRAN may signal the signature allocation using both common broadcast messages and WTRU-specific messaging. In the example shown above, s 1 , s 2 is a set of sequences (e.g., s 1 ={a 1 ,a 2 ,a 3 ,a 4}, s 2 ={b 1 ,b 2 ,b 3 ,b 4}, in this case, a i , b i is a signature sequence), and e 1 may denote an integer that represents the position of the sequence in the sequence set. 1 and e in RRC 1 For the case where 0 = 2 is received, the sequence allocated is a 2 It would be.

[0205] Referring to FIG. 49, a diagram illustrating a wake-up command energy signature allocation procedure initiated by a WTRU is shown. The WTRU can choose a signature sequence and signal to the eNB regarding its chosen sequence. The eNB can verify that no other WTRU has selected the same signature sequence. The WTRU can choose the signature sequence independently or with assistance from the EUTRAN. The steps of the latter procedure are described herein. It will be understood that one or more of the steps outlined below can be performed in a different order than presented herein, and that one or more steps can be added to or removed from the steps described below.

[0206] The eNB uses SIB signaling to determine the sequence set (e.g., s 1 ) in the sequence set as part of the RRC connection request. 1 ) randomly. The eNB may reject or confirm the selected sequence based on whether the sequence has already been selected by another WTRU. WTRU2 may select the same sequence selected by WTRU1. The eNB may reject the selected sequence and WTRU2 may repeat the sequence selection step (i.e., RRC connection request).

[0207] Referring to FIG. 50, a diagram illustrating adaptive power transmission for the wake-up process is shown. The amount of power allocated to wake up the sensor may be dynamic. The amount of power may depend on the number of unsuccessful attempts made to wake up the sensor. This method can ensure that the right amount of power increase is performed at a time that provides an acceptable trade-off between waking up the sensor and avoiding interference. For the first time point, the minimum required power may be used. For every subsequent unsuccessful attempt, the power can be increased stepwise until a wake-up confirmation is received. More precisely, the power allocation at time t can be written as follows: P t =P t-1 +δ(t-1)r. Equation 3

[0208] The variable r may represent the increment in power step size. δ(x) may represent the percentage of increase provided at any one time. For example, δ(x)=x 2can represent a quadratic increase at every unsuccessful attempt, while δ(x)=c can represent a constant increase at every unsuccessful instant. The above scheme can rely on wake-up confirmations to be able to adapt the transmit power allocation at every unsuccessful instant.

[0209] A "blind" scheme can occur where the transmitter does not expect to receive a wake-up confirmation. In this case, there can be a certain number of retransmissions to wake up the sensor with a power increase of δ(x).

[0210] The primary eNB may monitor the system information 2 (SIB-2) broadcast messages of neighboring cells. The primary eNB may infer the amount of power provided by the neighboring cell in the resource block of interest and the amount of additional power it may need to provide to wake up the sensor. It will be understood that one or more of the steps outlined below may be performed in a different order than presented herein, and that one or more steps may be added to or removed from the steps described below.

[0211] In step 1, the primary eNB may estimate the energy per resource element (EPRE) for the reference signal of a neighboring cell.

[0212] In step 2, the primary eNB B / ρ A It is possible to read the value of pb from SIB-2, which is defined as B is the reference signal power, and ρ A is the PDSCH power.

[0213] From steps 1 and 2, the primary eNB determines the PDSCH power per EPRE provided by neighbor cell i as

[0214]

number

[0215] Assuming that the primary eNB allocates N resource blocks for waking up the sensor, the estimated power on these resource blocks provided by neighbor cell i can be obtained as

[0216]

number

[0217] In this case, N RB indicates the number of resource elements per resource block.

[0218] The amount of additional power required to wake up the sensor is

[0219]

number

[0220] where P is the total power needed to wake up the sensor, and the quantity δ lumps together the estimation error of the neighboring cell's power and the path loss that needs to be compensated by each of the cells.

[0221] Referring to Figure 51, a diagram illustrating TX power adaptation based on sharing of RB usage information of cooperating eNBs is shown. The primary eNB can explicitly request power allocation in its resource blocks of interest from neighboring cells (secondary eNBs) over the X2 interface. Based on the power allocation by the neighboring cells, the primary eNB can estimate the required power very accurately.

[0222] In step 1, the primary eNB determines the next T'(T'>(T 2 -T 1 During the wake-up period, a cell can send out a request for a neighboring cell to provide a power allocation on its resource blocks of interest (i.e., resource blocks that are intended to be used for wake-up purposes). 2 Assuming that indicates when the WTRU / sensor needs to be paged, T 1 can be chosen based on the backhaul delay, which depends on the inter-site distance between the primary eNB and the requested cell, to ensure availability of information from neighboring cells before the paging moment.

[0223] If an eNB performs semi-persistent scheduling, power allocations can be provided by neighboring cells in a non-causal manner. Furthermore, instead of explicitly requesting power allocation by the primary eNB on specific resource blocks, neighboring cells can periodically report power allocations on a wider set of resource blocks (provided they contain the resource block of interest). The primary eNB can use the most recent received allocation, or the average received over the last few instances, as a good estimate. The advantage of this scheme is that there is no implicit deadline before the paging moment when the primary eNB needs to request a power allocation from a neighbor, albeit at the expense of accuracy.

[0224] In steps 2 and 3, power usage information for the near future may be provided by neighboring cells based on predefined power allocations to which they adhere, or based on a semi-persistent scheduling mechanism.

[0225] In step 4, a transmission at the paging instant may be sent from the primary eNB to the WTRU or the sensor.

[0226] The network can broadcast a group-specific unique energy signature as part of a system information message (e.g., SIB-2, SIB-3) to wake up a specific class of devices. The network can broadcast a device-specific unique energy signature as part of an RRC message (e.g., signaled on the PCCH logical channel) to wake up a specific device. The network can broadcast system information (e.g., tracking area identity, tracking area code, etc.) using a Tracking Area Update (TAU) command with a unique energy signature. A device can receive the TAU command using a passive receiver and interpret the unique energy signature to access the system information and trigger a Tracking Area Update procedure.

[0227] The above description may be applied to an IEEE 802.11 system. An AP may use a dedicated beacon i. The beacon frame may be dual purpose. The beacon frame may be a conventional beacon frame and / or a wake-up beacon frame. The OFDM symbols that make up the wake-up beacon frame may include a unique pilot sequence in a pre-configured set of subcarriers. The wake-up beacon frame may include a unique energy signature.

[0228] A STA can receive a wake-up beacon frame using a passive receiver, decode a unique pilot sequence in a pre-configured set of subcarriers of the OFMD symbols that make up the beacon frame, interpret the unique energy signature, and generate a wake-up interrupt.

[0229] The following description includes using the transmission of a dedicated beacon to wake up the STAs, which can serve as a conventional beacon frame for the STAs and as a wake-up signal with a unique energy signature for the passive receivers in the STAs.

[0230] Referring to Figure 52, a diagram illustrating the transmission of a dedicated beacon is shown. Figure 52 illustrates a mechanism by which a STA can be made aware of a dedicated beacon transmitted by an AP. A unique pilot sequence can be transmitted on a set of OFDM symbols during the transmission of a beacon frame by the PHY, on pre-configured subcarriers such as the wake-up pilot subcarriers shown in Figure 52 (e.g., a Zadoff Chu sequence of length 7).

[0231] A signature sequence for waking up a STA may be provided on a pre-configured set of subcarriers (e.g., wake-up signature subcarriers), which may be contiguous or distributed.

[0232] The presence of the unique wake-up pilot sequence on the wake-up pilot subcarrier can make the STA aware that the current OFDM symbol is part of a dedicated beacon frame being transmitted, and therefore the STA can ignore the wake-up signature subcarrier for decoding the beacon frame.

[0233] A passive receiver can decode the signal from the wake-up subcarrier and wake up the active TRX in the STA if the decoded signature matches its own wake-up signature. To prevent a passive receiver from waking up an active TRX during conventional transmission (i.e., to prevent false alarms), the secondary receiver can look for the signature in the wake-up carrier and the presence of a unique wake-up pilot sequence in the wake-up pilot subcarrier.

[0234] Referring to Figure 53, a diagram illustrating the transmission of a dedicated wake-up signal is shown. The dedicated wake-up signal may include a group of OFDM symbols in time. This signal may be used to transmit a unique energy signature associated with a wake-up command that may be used by a passive receiver in the STA to wake up the active TRX. This signal may be transmitted immediately before a beacon or whenever the AP senses that the medium is free (e.g., between consecutive beacon transmissions as shown in Figure 53). As mentioned above, there may be a unique identifier (e.g., a Zadoff Chu sequence of length 7) to remind the wake-up receivers that this OFDM frame is intended for them and for conventional STAs to discard this frame.

[0235] Individual and group wake-up procedures and collision avoidance are described herein. In conventional systems, STAs may be required to wake up at least several times the beacon period to know if they have data to receive. The following description includes a procedure for waking up only a subset of the STAs using their passive receivers (i.e., a group wake-up procedure).

[0236] In addition to waking up STAs only when necessary, the method described herein is able to avoid collisions, which may be a potential problem that may be present in the PS-POLL phase.

[0237] 54, a diagram illustrating wake-up command energy signature configuration, STA wake-up, and data transfer is shown. It should be understood that one or more of the steps outlined below can be performed in a different order than presented herein, and that one or more steps can be added to or removed from the steps described below.

[0238] Before a STA enters a doze state (i.e., when the STA transmits a null frame with the power management bit set to 1), the AP can dynamically allocate a wake-up command energy signature.

[0239] It is possible that the same signature is provided to multiple STAs going into a doze state, in which case the signature can be used by the AP to wake up multiple STAs, or a unique signature can be configured for each STA by the AP to wake them up.

[0240] Before a beacon is transmitted by an AP, the AP can wake up the STAs to which it intends to send buffered data. The STAs can be awakened by the AP sending a wake-up command with a previously configured unique signature.

[0241] A conventional PS-POLL procedure may then be initiated. One modification to the conventional PS-POLL procedure may be that only a subset of the STAs (i.e., their primary receivers) may be kept awake by the AP.

[0242] Although the AP may wake up a subset of the STAs, the Traffic Information Map (TIM), which indicates the data available to the STAs, may not be changed from the conventional system. This may be a result of the TIM containing data or storage items with information about other STAs that have not yet woken up due to the selective wake-up.

[0243] In the example call flow shown in Figure 54, both stations STA-1 and STA-2 can be woken up. However, the PS-POLL may only be successful for STA-1. Alternatively, the STAs can be woken up selectively based on the priority of the data that needs to be delivered (e.g., AC_VI, AC_VO, etc.), which can be known by the AP.

[0244] A conventional STA may set the power management bit to 1 before going to sleep. This allows the AP to know that the STA is going to enter sleep mode so that the AP can buffer packets.

[0245] For STAs that receive a small amount of data per wake-up cycle, the default operation may be to wake up for a specified amount of time (once they are woken up by the AP) and then immediately go to sleep without a "power management" message. The STA may send a message "M2M mode operation request" so that the AP knows that the STA is requesting to go to sleep after waking up for a certain amount of time. This configuration may be a one-time configuration that the STA may request from the AP. There may be a confirmation message "M2M mode confirm" from the AP to the STA to accept the M2M mode change. The STA may then wake up if it has data from the AP. If the STA wants to cancel the "M2M mode operation", it may have to wait until the data is delivered by the AP. Alternatively, the AP may poll the STA once every T seconds after waking it up, looking for the cancellation of the M2M mode. In this case, T may be a very large value.

[0246] Several signature sequences for STA wake-up are described herein. 0 ,s 1 ,...s N} may be allocated to wake up the STA, where s i is a unique signature sequence. i Any of the sequences may be used to wake up a STA, but each sequence will have a different impact on power saving capabilities. For example, 0 can be used to activate one active receive chain of a STA, and s 1may be used to activate two receive chains, and so on. Depending on the traffic to be sent to the STA, the AP can invoke the appropriate signature sequence. For example, if video traffic is to be delivered to the STA, the AP can invoke a signature sequence that will activate four receive chains at the STA. A signature sequence set can be constructed as a concatenation of the primary and secondary signature sequences, where S=[A p A s ], in this case, A p is the base signature sequence (to wake up the active TRX), and A s is used to invoke specific functions on the power saving capabilities of the STA

[0247]

number

[0248] It is possible for the secondary signature sequence to be a number of bits long (where N is the number of sequences in the signature set).

[0249] Although features and elements of the invention may be described in particular combinations or orders in the embodiments, each feature or element can be used alone without the other features and elements of the embodiments, or in various combinations with or without other features and elements of the invention.

[0250] Although the solutions described herein take into account protocols specific to IEEE 802.11, LTE, LTE-A, New Radio (NR), or 5G, it can be understood that the solutions described herein are not limited to this scenario and are applicable to other wireless systems.

[0251] Although the features and elements are described above in certain combinations, one of ordinary skill in the art will understand that each feature or element may be used alone or in any combination with the other features and elements. The methods described herein may be implemented in a computer program, software, or firmware embodied in a computer-readable medium for execution by a computer or processor. Examples of computer-readable media include electronic signals (transmitted over wired or wireless connections) and computer-readable storage media. Examples of computer-readable storage media include, but are not limited to, ROM, RAM, registers, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks and digital versatile disks (DVDs). A processor associated with software may be used to implement a radio frequency transceiver for use in a WTRU, UE, terminal, base station, RNC, or any host computer.

Claims

1. 1. A method for use in a wireless transmit / receive unit (WTRU) having a first transceiver and a second transceiver, the method comprising: receiving first configuration information using the first transceiver, the first configuration information including configuration information for a first discontinuous reception (DRX) cycle and configuration information for at least one second DRX cycle; entering a first DRX cycle of the first transceiver based on configuration information of the first DRX cycle; receiving a first message from a first network node using the second transceiver, the first message including information including a command to suspend the first DRX cycle and to use a second DRX cycle based on configuration information of the at least one second DRX cycle; determining a second DRX cycle of the first transceiver, the second DRX cycle being based on the at least one second DRX cycle configuration information and the received first message; activating the first transceiver to receive a second message based on the determined second DRX cycle; The method includes:

2. The method of claim 1 , wherein entering the first DRX cycle includes placing the first transceiver in a sleep mode.

3. The method of claim 1 , wherein each second DRX cycle is associated with a priority level.

4. The method of claim 3 , wherein a parameter of the received first message is based on an associated priority level.

5. The method of claim 1 , wherein the determined second DRX cycle has a shorter sleep cycle than the first DRX cycle.

6. 2. The method of claim 1, further comprising receiving a synchronization signal by the first transceiver in response to receiving the first message using the second transceiver.

7. The method of claim 1 , wherein the received first message includes an energy signature including one or more sections of different duration and amplitude having the same energy.

8. The method of claim 1 , further comprising extracting energy from the first message received by the second transceiver.

9. The method of claim 1 , wherein the received second message is a paging message.

10. The method of claim 9 , wherein the paging message is received at a paging occasion based on the determined second DRX cycle.

11. A processor; A first transceiver; A second transceiver; 1. A wireless transmit / receive unit (WTRU) comprising: The first transceiver is configured to receive first configuration information, the first configuration information including configuration information for a first discontinuous reception (DRX) cycle and configuration information for at least one second DRX cycle; The processor is configured to enter a first DRX cycle of the first transceiver based on configuration information of the first DRX cycle; the second transceiver is configured to receive a first message from a first network node, the first message including information including a command to suspend the first DRX cycle and to use a second DRX cycle based on configuration information of the at least one second DRX cycle; The processor is configured to determine a second DRX cycle of the first transceiver, the second DRX cycle being based on the at least one second DRX cycle configuration information and the received first message; The processor is further configured to activate the first transceiver; The first transceiver is further configured to receive a second message based on the determined second DRX cycle. W.T.R.U.

12. The WTRU of claim 11 , wherein the processor is configured to enter the first DRX cycle by placing the first transceiver in a sleep mode.

13. The WTRU of claim 11, wherein each second DRX cycle is associated with a priority level.

14. The WTRU of claim 13, wherein a parameter of the received first message is based on an associated priority level.

15. The WTRU of claim 11 , wherein the determined second DRX cycle has a shorter sleep cycle than the first DRX cycle.

16. A processor; A transceiver; A base station comprising: The processor and the transceiver sending a request to a neighboring cell to provide a power allocation for a resource block of interest; receiving impending power usage information from the neighboring cells based on a predetermined power allocation; transmitting a paging instant transmission to a wireless transmit / receive unit (WTRU); A base station configured to:

17. The base station of claim 16 , wherein the predetermined power allocation is according to or based on a semi-persistent scheduling mechanism.

18. 1. A method for use in a base station, comprising: sending a request to a neighboring cell to provide a power allocation for a resource block of interest; receiving impending power usage information from the neighboring cells based on a predetermined power allocation; transmitting a paging instant transmission to a wireless transmit / receive unit (WTRU); The method includes:

19. 20. The method of claim 18, wherein the predetermined power allocation is according to or based on a semi-persistent scheduling mechanism.

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