Leveraging synchronization coordination of a mesh network for low-power devices

Methods, apparatus, and systems for wireless communication are provided. A method for wireless communication includes configuring a first device for a first mode of communication, receiving wide area network (WAN) scheduling information from downlink signals received from a network entity when a radio air interface of the first device is configured for the first mode of communication, configuring the first device for a second mode of communication, determining a mesh network schedule based on the WAN scheduling information, and communicating wirelessly with a second device in accordance with the mesh network schedule when the radio air interface is configured for the second mode of communication. The first device and the second device may communicate at power levels below a power level threshold selected to cause the network entity to ignore transmissions between the first device and the second device.

TECHNICAL FIELD

The present disclosure relates generally to communication systems, and more particularly, to coordination of communications activities associated with low-power devices that are connected to mesh networks and wide area networks.

INTRODUCTION

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. Emerging telecommunication standards include fourth generation (4G) technologies such as Long Term Evolution (LTE), and fifth generation (5G) technologies. LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in wireless communications technologies. Preferably, improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

SUMMARY

In an aspect of the disclosure, a method, a computer program product, and an apparatus are provided that can improve coordination of communications activities associated with devices that are configured to be connected to mesh networks and wide area networks.

According to certain aspects, a method for wireless communication includes receiving wide area network (WAN) scheduling information from downlink signals received at a first device from an entity of the WAN when the first device is configured for a first mode of communication, and determining a mesh network schedule based on the WAN scheduling information. The first device may transmit wirelessly at a first power level to an entity in the WAN in a first mode of operation. The radio may be configured to spread data over time-domain resources in the first mode of operation. The first device may transmit wirelessly at a second power level from the first device to a second device in a mesh network in a second mode of operation. The radio may be configured to spread data over frequency-domain resources in the second mode of operation. The second power level may be lower than the first power level and may be selected to be less than a power level calculated to cause the entity in the WAN to ignore data transmissions by the first device in the second mode of communication if received by the entity in the WAN.

According to certain aspects, an apparatus configured for wireless communication includes a radio air interface and a processing circuit. The processing circuit may have one or more processors and at least one processor may be configured to receive WAN scheduling information from downlink signals received at a first device from an entity of the WAN when the first device is configured for a first mode of communication, and configure a mesh network schedule based on the WAN scheduling information. The at least one processor may be configured to cause the first device to transmit wirelessly at a first power level to an entity in the WAN in a first mode of operation. The radio may be configured to spread data over time-domain resources in the first mode of operation. The at least one processor may be configured to cause the first device to transmit wirelessly at a second power level from the first device to a second device in a mesh network in a second mode of operation. The radio may be configured to spread data over frequency-domain resources in the second mode of operation. The second power level may be lower than the first power level and may be selected to be less than a power level calculated to cause the entity in the WAN to ignore data transmissions by the first device in the second mode of communication if received by the entity in the WAN.

According to certain aspects, an apparatus configured for wireless communication includes means for communicating wirelessly on one or more radio frequency carriers, the means for communicating wirelessly including a radio air interface, means for configuring the radio air interface, where the radio air interface may be configured for a first mode of communication and for a second mode of communication, means for determining WAN scheduling information from downlink signals received from an entity of the WAN when the radio air interface is configured for the first mode of communication, means for determining a mesh network schedule, where the means for determining the mesh network schedule is adapted to configure the mesh network schedule based on the WAN scheduling information, and means for communicating wirelessly with a first mesh device in accordance with the mesh network schedule when the radio air interface is configured for the second mode of communication. The radio air interface may be configured to transmit at a first power level in the first mode of communication and to transmit at a second power level in the second mode of communication. The second power level may be lower than the first power level. The second power level may be selected to be less than a power level calculated to cause the entity in the WAN to ignore data transmissions by the first device in the second mode of communication if received by the entity in the WAN.

According to certain aspects, a computer readable medium stores computer executable code. The code may be executed by one or more processors on a processing circuit. The code may include instructions that cause the processing circuit to receive WAN scheduling information from downlink signals received at a first device from an entity of the WAN when the first device is configured for a first mode of communication, and determine a mesh network schedule based on the WAN scheduling information. The code may include instructions that cause the processing circuit to transmit wirelessly at a first power level to an entity in the WAN in a first mode of operation. The radio may be configured to spread data over time-domain resources in the first mode of operation. The code may include instructions that cause the processing circuit to transmit wirelessly at a second power level from the first device to a second device in a mesh network in a second mode of operation. The radio may be configured to spread data over frequency-domain resources in the second mode of operation. The second power level may be lower than the first power level and may be selected to be less than a power level calculated to cause the entity in the WAN to ignore data transmissions by the first device in the second mode of communication if received by the entity in the WAN.

DETAILED DESCRIPTION

Overview

Certain aspects of the disclosure relate to a wireless device that includes a single radio air interface that can be dynamically reconfigured to support a mode of operation that provides for long-range communications with an entity of a wireless access network. The device may be adapted according to certain aspects disclosed herein, such that it can synchronize timing and scheduling of one or more radio interfaces based on signaling received from the entity of the wide area network. The entity may be a scheduling entity such as a base station in a licensed wireless network, for example. Timing, and scheduling of mesh network communications may be synchronized to the timing and scheduling of wide area network communications. The timing and scheduling of the wide area network communications may be determined from downlink signals received from the entity. A schedule governing transmissions between devices on the mesh network may be established, configured and/or adjusted based on scheduling information transmitted in the downlink signals.

For example, networks of low-power devices with ever improving communications and processing capabilities may be employed to perform a variety of functions, including management and monitoring of equipment, environmental conditions, premises, processes and the like. A network of low-power devices may be connected through a mesh network utilizing unlicensed frequencies. Networks of low-power devices often lack central management. In some instances, data may be transmitted over ad hoc connections as the data becomes available. Activities in a network of low-power devices may be coordinated according to a loosely defined schedule that may, for example, define an imprecise time period for contacting a monitoring server.

According to certain aspects disclosed herein, scheduling and coordination is provided for communication devices that are connected or capable of being connected to a licensed wide area network such as a cellular telecommunications network, and that may also connect to a network of low-power devices.

In one example, a plurality of devices in a mesh network may be within range of an entity of the wide area network such that each of the plurality of devices in the mesh network can receive scheduling information transmitted by the entity. Moreover, the scheduling information transmitted by the entity may provide each device with additional timing information that permits each device to adjust its internal mesh network schedule to more accurately track timing of the entity and/or to offset delays relative to other devices in the mesh network. Accordingly, mesh network devices may accurately and reliably establish or determine a mesh network schedule that is synchronized across the mesh network. Two devices that are unable to directly communicate due to distance may nevertheless maintain synchronized mesh network schedules when both devices can receive scheduling information from the entity of the wide area network.

The mesh network schedule may be configured to avoid conflicts with wide area transmission schedules. For example, a first device that is configured for communicating on the mesh network and the wide area network may establish a mesh network schedule that enables the device to communicate with a second device when the first device is idle with respect to wide area communications. In some instances, the first device may conserve power through the use of a single radio air interface for both mesh network and wide area network communications.

Accordingly, in one or more exemplary embodiments, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may include any combination of available media that can be accessed by a computer.

Certain aspects of the disclosure address networks of low-power devices used in communication systems. In some scenarios, these devices can be used in newer generations of radio access technologies (RATs), including in fifth generation (5G) and later networks, as well as in fourth generation (4G) and earlier networks. The configuration and operation of a 4G LTE network architecture is described herein by way example, and for the purpose of simplifying descriptions of certain aspects that may apply to multiple RATs. That is, scenarios of LTE networks, for example, are discussed yet aspects of this disclosure are not limited. Rather this is done to help the reader understand certain implementations and embodiments.

The E-UTRAN includes the evolved Node B (eNB)106and other eNBs108. The eNB106provides user and control planes protocol terminations toward the UE102. The eNB106may be connected to the other eNBs108via a backhaul (e.g., an X2 interface). The eNB106may also be referred to as a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), or some other suitable terminology. The eNB106provides an access point to the EPC110for a UE102. Examples of UEs102include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player), a camera, a game console, a tablet, or any other similar functioning device. The UE102may also be referred to by those skilled in the art as a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.

The eNB106is connected by an SI interface to the EPC110. The EPC110includes a Mobility Management Entity (MME)112, other MMEs114, a Serving Gateway116, and a Packet Data Network (PDN) Gateway118. The MME112is the control node that processes the signaling between the UE102and the EPC110. Generally, the MME112provides bearer and connection management. All user IP packets are transferred through the Serving Gateway116, which itself is connected to the PDN Gateway118. The PDN Gateway118provides UE IP address allocation as well as other functions. The PDN Gateway118is connected to the Operator's IP Services122. The Operator's IP Services122may include the Internet, an intranet, an IP Multimedia Subsystem (IMS), and a PS Streaming Service (PSS).

FIG. 2is a diagram illustrating an example of an access network200in an LTE network architecture. In this example, the access network200is divided into a number of cellular regions (cells)202. One or more lower power class eNBs208may have cellular regions210that overlap with one or more of the cells202. The lower power class eNB208may be a femto cell (e.g., home eNB (HeNB)), pico cell, micro cell, or remote radio head (RRH). The macro eNBs204are each assigned to a respective cell202and are configured to provide an access point to the EPC110for all the UEs206in the cells202. There is no centralized controller in this example of an access network200, but a centralized controller may be used in alternative configurations. The eNBs204are responsible for all radio related functions including radio bearer control, admission control, mobility control, scheduling, security, and connectivity to the serving gateway116.

Networks, including packet-switched networks may be structured in multiple hierarchical protocol layers, where the lower protocol layers provide services to the upper layers and each layer is responsible for different tasks.FIG. 3is a diagram300illustrating an example of a radio protocol architecture for the user and control planes in an LTE implementation. The radio protocol architecture for the UE and the eNB is shown with three layers: Layer 1, Layer 2, and Layer 3. Layer 1 (L1 layer) is the lowest layer and implements various physical layer signal processing functions. The L1 layer will be referred to herein as the physical layer306. Layer 2 (L2 layer)308is above the physical layer306and is responsible for the link between the UE and eNB over the physical layer306.

In the user plane, the L2 layer308includes a media access control (MAC) sublayer310, a radio link control (RLC) sublayer312, and a packet data convergence protocol (PDCP)314sublayer, which are terminated at the eNB on the network side. Although not shown, the UE may have several upper layers above the L2 layer308including a network layer (e.g., IP layer) that is terminated at the PDN gateway118on the network side, and an application layer that is terminated at the other end of the connection (e.g., far end UE, server, etc.).

In the control plane, the radio protocol architecture for the UE and eNB is substantially the same for the physical layer306and the L2 layer308with the exception that there is no header compression function for the control plane. The control plane also includes a radio resource control (RRC) sublayer316in Layer 3 (L3 layer). The RRC sublayer316is responsible for obtaining radio resources (i.e., radio bearers) and for configuring the lower layers using RRC signaling between the eNB and the UE.

Radio Link Setup in Wide Area Networks

A communication device, such as an access terminal, UE, mobile device, or the like, may establish a connection with a subscription network through a WAN using one or more registration, attachment, provisioning and/or other procedures. For example, radio link setup in an LTE network may involve establishment of one or more radio bearers between an access node that provides access to a network and a communication device. Radio link setup typically includes a security activation exchange. A session bearer, which may be a logical bearer or logical channel, may then be established over the radio link and one or more services and/or communications may be established over the session bearer. The session bearer, services and/or communications may be secured by one or more security keys. As part of the session bearer setup, an authentication request, and/or one or more key exchanges may take place. In networks operating according to an LTE-compatible protocol, keys may be derived by the communication device based on algorithms provided by one or more network entities.

FIG. 4illustrates an example of a protocol stack that may be implemented in a communication device operating in a LTE packet-switched network. In this example, the LTE protocol stack402includes a Physical (PHY) Layer404, a Media Access Control (MAC) Layer406, a Radio Link Control (RLC) Layer408, a Packet Data Convergence Protocol (PDCP) Layer411, a RRC Layer412, a Non-Access Access (NAS) Layer414, and an Application (APP) Layer416. The layers below the NAS Layer414are often referred to as the Access Stratum (AS) Layer403.

The RLC Layer408may include one or more channels410. The RRC Layer412may implement various monitoring modes for the user equipment, including connected state and idle state. The NAS Layer414may maintain the communication device's mobility management context, packet data context and/or its IP addresses. Note that other layers may be present in the protocol stack402(e.g., above, below, and/or in between the illustrated layers), but have been omitted for the purpose of illustration. Radio/session bearers413may be established, for example at the RRC Layer412and/or NAS Layer414. Initially, communications to and/or from a communication device may be transmitted (unprotected or unencrypted) over an unsecured common control channel (CCCH). The NAS Layer414may be used by the communication device and an MME to generate security keys. After these security keys are established, communications including signaling, control messages, and/or user data may be transmitted over a Dedicated Control Channel (DCCH). NAS context may be reused at the time of Service Request, Attach Request and Tracking Area Update (TAU) Request.

FIG. 5is a block diagram500of an eNB510in communication with a UE550in an access network. In the DL, upper layer packets from the core network are provided to a controller/processor575. The controller/processor575implements the functionality of the L2 layer. In the DL, the controller/processor575provides header compression, ciphering, packet segmentation and reordering, multiplexing between logical and transport channels, and radio resource allocations to the UE550based on various priority metrics. The controller/processor575is also responsible for HARQ operations, retransmission of lost packets, and signaling to the UE550.

At the UE550, each receiver554RX receives a signal through its respective antenna552. Each receiver554RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor556. The RX processor556implements various signal processing functions of the L1 layer. The RX processor556performs spatial processing on the information to recover any spatial streams destined for the UE550. If multiple spatial streams are destined for the UE550, they may be combined by the RX processor556into a single OFDM symbol stream. The RX processor556then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT). The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the eNB510. These soft decisions may be based on channel estimates computed by the channel estimator558. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the eNB510on the physical channel. The data and control signals are then provided to the controller/processor559.

The controller/processor559implements the L2 layer. The controller/processor can be associated with a memory560that stores program codes and data. The memory560may be referred to as a computer-readable medium. In the UL, the controller/processor559provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the core network. The upper layer packets are then provided to a data sink562, which represents all the protocol layers above the L2 layer. Various control signals may also be provided to the data sink562for L3 processing. The controller/processor559is also responsible for error detection using an acknowledgement (ACK) and/or negative acknowledgement (NACK) protocol to support HARQ operations.

In the UL, a data source567is used to provide upper layer packets to the controller/processor559. The data source567represents all protocol layers above the L2 layer. Similar to the functionality described in connection with the DL transmission by the eNB510, the controller/processor559implements the L2 layer for the user plane and the control plane by providing header compression, ciphering, packet segmentation and reordering, and multiplexing between logical and transport channels based on radio resource allocations by the eNB510. The controller/processor559is also responsible for HARQ operations, retransmission of lost packets, and signaling to the eNB510.

Channel estimates derived by a channel estimator558from a reference signal or feedback transmitted by the eNB510may be used by the TX processor568to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor568are provided to different antenna552via separate transmitters554TX. Each transmitter554TX modulates an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the eNB510in a manner similar to that described in connection with the receiver function at the UE550. Each receiver518RX receives a signal through its respective antenna520. Each receiver518RX recovers information modulated onto an RF carrier and provides the information to a RX processor570. The RX processor570may implement the L1 layer.

The controller/processor575implements the L2 layer. The controller/processor575can be associated with a memory576that stores program codes and data. The memory576may be referred to as a computer-readable medium. In the UL, the control/processor575provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover upper layer packets from the UE550. Upper layer packets from the controller/processor575may be provided to the core network. The controller/processor575is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

As mentioned above, Applicant has discussed exemplary LTE-type networks to provide a foundation for the reader for certain implementations. Below, Applicant discusses additional concepts, implementation, and embodiments enabling and providing additional communication network devices, methods, and systems incorporating one on or more features for dynamically reconfigurable radio air interfaces in low-power devices that communicate over a mesh network and a wide area network.

Wide Area Networks of Low Power Devices

With the advent of ubiquitous network access and the provision of wireless communications capabilities in ever-increasing numbers of appliances and sensors, there is continuous demand for improved access to such wireless-capable appliances and sensors. Appliances and sensors are typically equipped with low-power wireless transmitters and are conventionally configured to be connected to local area networks that have limited physical range, which may be less than a few hundred meters. A large percentage of wireless-capable appliances and sensors have insufficient power to directly access in a WAN that may be operated, for example, by a telecommunications carrier using a licensed RF spectrum.

WANs typically require devices to transmit with sufficiently high power to reach a base station or a small cell that may have a radius of coverage measured in kilometers. In one example, a device may be required to transmit at power levels of 23 dBm or more to reach a base station.FIG. 6is a graph from the CDMA Development Group illustrating mobile station (MS) transmit power for a population of devices, measured by cumulative distribution function (CDF). It may be observed that the median transmit power required to close a link is approximately −2 dBm or less for most users, but when low power devices incur addition losses e.g., anticipated 20 dB uplink loss from removal of a PA on the device, then almost half of the nodes in a network may be operating at peak power and in some cases unable to close current minimum data rate requirements.

Reducing transmit power required to close a link to 0 dBm, for example, can enable lower power devices to operate in the WAN, but may require long transmissions to close the uplink, which may result in lower overall energy efficiencies than the alternative of using an additional power amplifier. Conventional approaches for connecting low power devices to WANs are fragmented and include different components of unlicensed mesh networks and cellular access.

A managed communication system provided in accordance with certain aspects disclosed herein can efficiently enable direct and mesh networking in support of wide area networks of low-power devices. In the managed communication system, a single reconfigurable radio air interface may be provided for both long-range wireless communications links to a base station and for short-range mesh links between low-power devices. The low-power devices may support one or more RSMA interfaces as described herein. In one example, multiple access may be provided using a low rate channel code, which may be used to encode data over frequency-domain and/or time-domain resources. According to certain aspects, mesh networking may be employed to carry uplink communications from low-power devices, and direct downlink transmissions may be used by a wide area network to transmit data and control information to the low power devices. According to certain aspects, the licensed FDD spectrum may be flexibly used in a managed direct and mesh access environment.

Single Radio Air Interface for Mesh and Direct Links

FIG. 7is a drawing that illustrates an example of a wide area network of low-power devices700that may be configured to use uplink mesh, downlink direct (UMDD) communications in accordance with certain aspects disclosed herein. The wide area network of low-power devices700may employ an RSMA scheme adaptable across direct communication links718,720and mesh network connections728,730,732. The wide area network of low-power devices700may include the Internet704and the wide area network of low-power devices700may be referred to as the Internet of Everything (IoE) or Internet of Things (IoT).

A device may be considered a low-power device having a number of features. For example, a device may be a low-power device when it transmits at a power level below a power level threshold that causes or results in its transmissions being ignored by a base station or other entity in a licensed radio access network. Low-power devices may be classified according to their maximum transmit power, which can limit communication range. For example, the IEEE 802.15.4 standard is typically used in networks that have a transmission range of less than 10 meters, and defines a minimum power level of −3 dBm (0.5 mW), with transmission power being limited to 0 dBm (1 mW), 4 dBm (2.5 mW), or 20 dBm (100 mW), according to application. The determination of power-level may be based on an effective radiated power or equivalent radiated power (ERP), or an Effective Isotropic Radiated Power (EIRP). ERP may be understood as a standardized theoretical measurement obtained by calculating system losses and system gains. The EIRP may be employed to take beamforming and other output power concentrating factors into account. In one example, each of a plurality of low-power devices706,708,710,712,714may be referred to as an IoE device, and may have a reduced transmit power of 0 dBm.

In some examples, a device may be considered a low-power device when it transmits at a power level that is calculated or expected to be undetected by scheduling entities and/or other devices in a wide area network. In some examples, the transmission power of a low-power device may be selected to be less than a threshold power level. The threshold power level may be predefined, or configured by a network entity, and/or the threshold power level maybe calculated from measurements and other information received from one or more access terminals, base stations, scheduling entities, or other devices. The threshold power level may be calculated to cause the entity in the wide area network to ignore data transmissions by the low-power device, if the transmissions are received by the entity in the wide area network. In one example, the threshold power level may be calculated as the minimum transmission power level that corresponds to a received power level that is detectable at a scheduling entity, base station or the like. In another example, the threshold power level may be calculated as the minimum transmission power that corresponds to a received power level for signals that are not ignored or filtered by a scheduling entity, base station or the like. In some instances, low-power signals transmitted by a low-power device may be detected by a scheduling entity or other entity in the wide area network. In some instances, a scheduling entity or other entity in the wide area network may treat detected signals transmitted by a first low-power device to a second low power device as interfering signals, and may filter such interfering signals.

Some IoE devices706,708may establish direct uplink and downlink connections718,720with a base station702. In one example, the IoE devices708,708may connect with the base station702using low rate coding over a single-carrier waveform. A multicarrier OFDM variant of RSMA may be employed to support mesh communications between IoE devices706,708,710,712,714. RSMA can support unscheduled (asynchronous) transmissions that may reduce latency and on-time of the IoE devices706,708,710,712,714.

Direct communications in network700can have varying characteristics. For example, uplink communications from meshed IoE devices710,712,714may be carried through mesh network connections728,730,732that interconnect directly connected IoE devices706,708with mesh-connected IoE devices710,712,714. The meshed IoE devices710,712,714may receive direct downlink signals722,724,726from the base station702. In the example, one IoE device708may serve as an aggregator for other IoE devices710,712,714. An IoE device708may be selected as an aggregator based on proximity to a base station702and/or another node of the mesh network, power availability, and or after negotiation with other nodes of the mesh network.

The same radio access technology (RAT) may be used in mesh network connections728,730,732and direct communication links718,720. For example, RSMA may provide single-carrier and OFDM variants. The single-carrier variant may be advantageously used for direct communications with a base station702, while OFDM may be well-suited for a mesh network. In one example, the mesh network connections728,730,732and the direct communication links718,720may use a spreading code over a single-carrier waveform as one instance of RSMA. The mesh network connections728,730,732may be scaled and numerically related to the direct communication link718,720. In one example, OFDM may be used with a nested timeline and scaled symbol duration. The OFDM variant of RSMA may provide robustness in the presence of collisions, and the symbol size in the OFDM variant may be shorter in time than in the single-carrier variant, here a single-carrier waveform with frequency domain equalization (SC/FDE). In one example, the use of OFDM with its smaller symbol sizes enables the IoE devices706,708,710,712,714to process received signals and return to dormant mode more quickly, thereby reducing power consumption. In some instances, multi-hop links730/732to an IoE device714that pass through multiple IoE devices708,712may be prescheduled to save power.

In some examples, an IoE device706,708,710,712,714may employ a single configurable radio air interface for communicating over a mesh network (mesh waveform) and directly (direct waveform) with a base station702. A direct waveform (see direct communications links718,720) may support large radius networking frequency selectivity. The mesh waveform may support shorter-range mesh network connections728,730,732. The mesh waveform may comply with timelines of the direct waveform. Compliance with the timelines of the direct waveform may include the use of similar or scaled numerologies to obtain a simple re-configured radio and modem. In some instances, compatibility between mesh and direct networks permits IoE devices706,708,710,712,714to demodulate cellular broadcasts efficiently. The single-radio air interface may provide unified multiple access across both direct communications links718,720and mesh network connections728,730,732.

RSMA may spread data and control signaling across resource elements that include time and/or frequency resource elements. When single-carrier RSMA is used, for example, data may be spread across time domain resource elements or chips. In TDD systems, a frame may be divided into slots that are composed of a predefined number of chips. In one example, a 10 ms frame may be divided into 15 slots, each slot having 2560 chips. In OFDM systems, frequency domain resources (sub-channels) and time domain resources may be available for spreading. A single-radio air interface may be configured to switch between single-carrier and OFDM variants of RSMA. The single-radio air interface can minimize RF front-end costs, including in implementations where fewer bands are to be supported. Bandwidth supported may include licensed bands and unlicensed lower bands.

FIG. 8illustrates two configurations800,820for a single air interface802according to certain aspects disclosed herein. In the first configuration800, the air interface802may be configured for a single-carrier variant of RSMA that spreads coded bits across time domain resource elements. RSMA may be implemented using low rate coding that enables grant-free transmission with reasonable loading characteristics. A single-carrier implementation of RSMA may be characterized by lowered PAPR with respect to multi-carrier implementations. Single-carrier RSMA may be used for communicating with a distant base station, for example. In the first configuration800, an input804of the air interface802is provided to a coder806. The coder may operate at a low code rate where code rate may be defined as the chip rate of a code, and which may be expressed as a number of chips per second at which the code is transmitted or received. The output of the coder806is optionally interleaved by an interleaver808before spreading by the spreader and/or scrambler810. A cyclic prefix (CP) is added by a CP module or circuit812before the resulting spread signal is up-converted814to obtain an output816.

In the second configuration820, the air interface802may be configured for an OFDM variant of RSMA. The OFDM variant of RSMA may be used for downlink and mesh communications links. The use of OFDM may result in symmetric complexity between transmit and receive chains. For example, fast Fourier transform (FFT) processing and inverse fast Fourier transform (IFFT) processing may be split between the transmit and receive chains, rather than being concentrated in the receiver. OFDM enables single-tap equalization while the use of low rate coding allows for robustness to multiuser interference, such that the strongest signal is decodable. In the second configuration820, the input804of the air interface802is provided to the coder806, and the output of the coder806may be optionally provided to the interleaver808before spreading by the spreader and/or scrambler810. In this configuration820, the signal sequence output by the spreader and/or scrambler810is converted to parallel in the serial to parallel convertor822. This allows for parallel signals to be sent across different sub-channels in the OFDM waveform through suitable processing by the IFFTs824. The outputs of the IFFTs824are provided to a parallel to serial convertor826for conversion back to a serial signal. Finally, a CP is added by the CP module or circuit812, before the resulting frequency-spread signal is up-converted814to obtain an output828.

As illustrated inFIG. 8, a single radio can be configured to support different variants of a coding scheme. A common resource spread coding scheme may be implemented using the coder806, interleaver808and spreader and/or scrambler810to feed a “waveform front-end” that operates to spread the coded signal over time or frequency resources. The coding scheme may be a low-density parity-check (LDPC) code or other coding scheme suitable for use in a shared spread spectrum, and/or multipath network. The use of such a low-rate code followed by a configurable modulation stage that can select between OFDM or single-carrier implementations permits a single radio device to support both mesh communications and direct communications with a scheduling entity such as a base station. Equipped with such a radio device, a mobile device deployed in a mesh network may communicate with other devices of its class and more distant base stations.

A radio air interface may be adapted according to certain aspects disclosed herein to enable dynamic reconfiguration of a single radio to support one or more variants of a coding scheme. In one example, a dynamically reconfigurable radio air interface may include circuits and modules that can be combined to communicate using a single-carrier variant of RSMA in a first configuration, and to communicate using an OFDM variant of RSMA in a second configuration. In some examples, the dynamically reconfigurable radio air interface may support different low-rate coding schemes that can be used with different waveforms.

FIG. 9is a block schematic diagram900that illustrates an example of a single radio air interface902used for RSMA with a configurable waveform front-end that may support single-carrier and multi-carrier RSMA. In one example, the air interface902may be configured for operation with single-carrier RSMA and OFDM RSMA. The air interface902may support single-carrier RSMA in a first mode of operation and multi-carrier RSMA in a second mode of operation. In many instances, hardware, logic and software in an RSMA air interface902may be reconfigured and/or reused based on a selected mode of operation.

The RSMA air interface902may operate as described generally in relation toFIG. 8for the single-carrier and multi-carrier RSMA modes of operation. That is, an input904of the air interface902is provided to a coder906, which may operate at a low code rate. The output of the coder906is optionally interleaved by an interleaver908before spreading by the spreader and/or scrambler910. A cyclic prefix (CP) is added by a CP module or circuit922before the resulting spread signal is up-converted928to obtain an output930.

A mode select signal932may determine the mode of operation of the RSMA air interface902. In one example, the mode select signal932may control the configuration of hardware, logic and software. In the depicted example, the mode select signal932may control the operation of multiplexing, de-multiplexing, and/or switching logic912,926. The mode select signal932may control the multiplexing, de-multiplexing, and/or switching logic912,926such that OFDM circuits and modules924are inserted into the processing chain of the air interface902in the second mode of operation.

The mode select signal932may be used to switch between modes of operation of the RSMA air interface902in accordance with one or more schedules and/or application needs. In one example, a communication device equipped with the RSMA air interface902may receive scheduling information from a scheduling entity of a WAN. The mode select signal932may be controlled by a processor, controller, processing circuit, state machine or sequencer in accordance with the scheduling information received from the scheduling entity of the WAN such that the RSMA air interface902is configured for the first mode of operation at those times specified by the scheduling information when the communication device is expected to listen or otherwise communicate on the WAN. In another example, an application processor may operate the mode select signal932to select the first mode of operation in order to search for, or connect to a WAN. In yet another example, an application processor may operate the mode select signal932to select the second mode of operation while communicating over a mesh network.

The RSMA air interface902may be configured for other modes of operation. For example, the radio air interface902may operate in a third mode of operation in which a combination of single-carrier and multi-carrier schemes may be utilized to carry data between two or more entities using both a single-carrier RSMA connection and an OFDM RSMA connection. In the third mode of operation, the mode select signal932may control the multiplexing, de-multiplexing, and/or switching logic912,926to provide a first portion of the spread coded data (output by the spreader and/or scrambler910) to the single-carrier path914and a second portion to the OFDM circuits and modules924. The radio air interface902may be configured to spread data over a combination of time-domain resources and frequency-domain resources in the third mode of operation. The third mode of operation may support certain types of communication with one or more base stations and/or with one or more devices in a mesh network.

According to certain aspects, the use of asynchronous RSMA can improve the performance of IoE devices by providing low-power, low-latency direct links between IoE devices and a base station.FIG. 10includes timing diagrams1000and1040that illustrate certain advantages of using relaxed uplink synchronism, including shortened cold starts after large timing drifts associated with IoE devices that are not constantly synchronized with the base station. In some examples, significant timing drifts may occur after time periods of 10 seconds or more, when the internal clock of the IoE device has a specified tolerance of 100 parts per million (ppm) clock. In one example, asynchronous RSMA may allow uplink transmissions for small payloads and data rates without an exchange of request and grant messages. Longer transactions may require re-transmission and closed loop power control. Downlink communications remain synchronous to provide a general timing reference. IoE devices need not be configured for transmit advance protocols prior to any uplink transmissions.

InFIG. 10, a first timing diagram1000illustrates conventional synchronous operation. An IoE may detect an event1002that causes the IoE to generate event information to be transmitted to the network. The event may be internal or external and may be generated by a timer, for example. The IoE commences a listening period1004during which the IoE may acquire network synchronization information1006,1008. The network synchronization information1006,1008may relate to frequency tracking synchronization1024and frame synchronization1026. The IoE may also receive control information including parameters transmitted in broadcasts1010,1012that enable the IoE to acquire system synchronization1028. The IoE may then transmit a request message1014and receive one or more response messages1016that may include a grant of resources and timing advance information. The IoE may then transmit the event information in one or more data transmissions1018on the uplink, and the base station may receive the data. The IoE may wait for acknowledgement1020of receipt of the data transmission before determining that the event information has been properly received at which point the IoE device can sleep1022.

FIG. 10includes a second timing diagram1040that illustrates the operation of an asynchronous RSMA link. Here, the IoE may enter a listening period1044after detecting an event1042. When the IoE has acquired frequency-tracking synchronization1054based on a downlink transmission1046, the IoE may transmit the event information in one or more data transmissions1048on the uplink, and the base station may receive the data. The IoE may then wait for acknowledgement1052of receipt of the data transmission before determining that the event information has been properly received. Accordingly, the transaction triggered by the event1042in an asynchronous RSMA system may require significantly less time to process than a similar event1002on a synchronous system. Collisions may occur at the base station during a period during which an asynchronous transmission from a different IoE is received (e.g., data transmissions1048). The period may be related to or calculated based on differences in propagation delay for the two IoE devices.

A single radio air interface902used for RSMA may maintain a wireless connection with a scheduling entity of a licensed wireless access network concurrently with one or more mesh network connections. In one example disclosed herein, scheduling information received from the licensed wireless access network may be used for scheduling communications within the mesh network. Accordingly, a device may schedule mesh communications in timeslots when the device is not involved in communication with the licensed wireless access network. In this mode, the resource spreading scheme employed by wireless device may be regarded as spreading data over both time-domain and frequency-domain resources when communicating on the mesh network.

In some instances, a device may maintain a wireless connection with a scheduling entity of a licensed wireless access network concurrently with one or more mesh network connections when the schedules of the licensed wireless access network and the mesh network are uncoordinated and/or unsynchronized. In these instances, collisions may occur in which the device is simultaneous scheduled to communicate on both the licensed wireless access network and the mesh network. When a collision occurs, the device may selectively provide access to the radio interface for applications communicating on one of the networks and deny access to another application communicating on the other network. A network may be selected for access based on priority, nature of the network, quality of service requirements, power budget, and for other reasons. In one example, access to the licensed wireless access network may be selected when there is a high probability that a connection between the device and the licensed wireless access network may be broken, and where reestablishing such connection may consume significant time and bandwidth resources and/or system power. In another example, access may be denied to the application communicating over the more resilient network connection. That is, access to the radio air interface may be granted for communications over a network connection that is less resilient, and where for example a retransmission scheme is supported for the more resilient network connection. In another example, communications with the licensed wireless access network may be granted access when the mesh network operates in an ad hoc, or connectionless manner.

According to certain aspects, RSMA uplink multiple access designs may be flexible in providing for the number of access terminals supported. The flexibility may be provided with less overhead and scheduling latency. Moreover, RSMA may be characterized by good performance for channels that have low signal-to-noise ratios (SNRs) and tight rise over thermal (RoT) control. RoT is related to the ratio of total interference received at the base station and thermal noise.

According to certain aspects, the UE in RSMA networks may be pre-registered and a signature sequence can be assigned. The signature sequence may include a scrambling code, interleaving pattern, etc. The transmit frequency band to be used by the UE may be specified. In some instances, a target wakeup time may be scheduled in order to more uniformly and/or effectively distribute traffic in the time domain.

In operation, the UE employs open-loop power control upon wakeup where, for example, the UE may measure downlink received power to determine the uplink transit power. The UE may then switch to closed-loop power control during data transmission.

According to certain aspects, one or more multi-user detection (MUD) schemes may be employed. MUD schemes may employ one or more approaches including, for example, approaches that treat interference as noise, perform successive interference cancellation, and/or joint-iterative decoding (seeFIG. 11). Some RATs, including 5G RATs may enable all approaches. The MUD schemes may be applied to both direct links and mesh links. Some MUD approaches may provide improved detection when substantial jitter is present.

According to certain aspects, provisions may be made for differences between communications related to access channels and communications involving traffic channels. Access channels are typically less power-controlled than traffic channels. In some instances, high-power access channel probes that have been decoded prior to traffic channel decoding may be cancelled. In some instances, access channels can be revisited after additional traffic channel decoding and cancellation has been performed.

According to certain aspects, an uplink access probe may include a preamble and certain identifying information. The preamble and identifying information may be separated in the time domain, with the preamble being transmitted before transmission of the identifying information is commenced. The identifying information may include a unique device identifier (device ID) of the IoE, a code and/or modulation format, and a format of the pilot sequence. The identifying information may be selected using open-loop power control. In some instances, the identifying information and/or preamble can be jointly encoded using, for example, a tail-biting code and repetition.

According to certain aspects, a traffic slot structure may be defined for use in uplink, downlink, and mesh transmissions. In one example, a single-carrier pilot, control, and/or traffic channels may be time-division multiplexed where the same transmit power is maintained over a packet frame. This type of traffic slot structure may provide a lower PAPR through BPSK, QPSK, and/or 8-PSK modulation and variants thereof. A pilot may be transmitted mid-amble, although it may be less convenient to process two discontinuous data bursts in some implementations.

In another example, OFDM pilot, control, and/or traffic channels may be time-division multiplexed and frequency-division multiplexed over a packet frame. Under this approach, better sensitivity modulation and/or demodulation can be achieved, albeit at a higher PAPR.

In some instances, the traffic-to-pilot resource ratio can be adjusted based on a desired operating point. A data and/or control channel may be encoded using a low-rate FEC code, such as a low-rate LDPC code or a turbo code, to achieve a high coding gain and consequently a reduction in required transmit power.

According to certain aspects, demodulation complexity may be reduced to save power. For example, simplified antenna diversity may be supported or antenna diversity may not be supported. The number of HARQ transmissions may be reduced, or error control may rely on ARQ.

Certain power-saving options may be available with respect to channel coding. For example, LDPC may be employed with simplified decoders. The iterative decoding message bit-widths and node functions may be scaled down and/or decoding can be performed with a bit-flipping algorithm for all bit operations. These power-saving methodologies and techniques may compare well with traditional techniques such as convolutional or Reed Solomon encoding techniques.

In some examples, a unified design of air-interface supports direct and mesh links with single radio. The links may use the same waveform and/or related or scaled numerologies between links to reduce complexity. Down-scaling of complexity may be provided to reduce power on short-range links.

In some examples, an adaptable RSMA scheme is employed across mesh and direct networks. RSMA may be used with information and overhead bits spread across time/frequency resources. RSMA may be applied to both single-carrier and multi-carrier (e.g., OFDM) waveforms with minor modifications.

In some examples, any combination of scrambling, spreading, and interleaving may be included. Time division of pilot and control may be supported to reduce PAPR in a single-carrier waveform.

Uplink Mesh/Downlink Direct Transmissions for IoE Device Networks

As discussed elsewhere herein, networks of IoE devices configured to communicate using RSMA may include IoE devices that have insufficient transmit power IoE to close the uplink connection. For example, IoE devices may have transmit power in the vicinity of 0 dBm. For the purposes of this discussion, it can be assumed that a base station is located within range of the IoE devices such that the downlink can be received at the IoE devices with sufficient power to enable efficient decoding by the IoE devices. Certain aspects disclosed herein provide systems, apparatus and methods that enable timing within a mesh network to be aligned, synchronized and/or coordinated with timing defined for a radio access network by a base station or other network entity. In some examples, a first device and second device in a mesh network can synchronize their timing when the first and second devices are out of range of one another by basing mesh network timing on base station synchronization signals. Certain aspects disclosed herein provide systems, apparatus and methods that enable an IoE mesh to close the uplink connection.

FIG. 12includes a diagram1200that illustrates a mesh network1218of IoE devices1204,1206, and1208. A base station1202may provide downlink channels that can be received by the IoE devices1204,1206, and1208. In the example, at least one IoE device1204has established an uplink connection1210with the base station1202. Each of the IoE devices1204,1206, and1208may monitor downlink transmission1214,1216from the base station1202. In the example, two IoE devices1206,1208communicate on the uplink using the aggregator IoE device1204.

According to certain aspects, the downlink frequencies may be used for discovery and coordination in the mesh network1218. The IoE devices1204,1206, and1208may include power constrained and/or plugged-in aggregators.

FIG. 12includes a mesh network subscriber domain1220that illustrates certain aspects related to discovery, connectivity, and traffic in the subscriber domain1220, including certain aspects related to subscriber domains and opportunistic relays. The subscriber domain1220may include a plurality of IoE devices that includes the IoE devices1222,1224,1226, and1228. The IoE devices1222,1224,1226, and1228may include power constrained and/or plugged-in aggregators.

IoE device discovery procedures in the subscriber domain1220may be performed using broadcasts of very short messages and/or signals. In one example, the short messages may include between 10 and 100 bytes, and these messages may advertise communication services associated with one or more of the IoE devices1222,1224,1226,1228. The communication services may include relay, aggregator, and/or access services. The very short messages may be used to propagate system configuration and/or to provide signals used for synchronization. A discovery subsystem configured for the subscriber domain1220may operate according to a predefined time scale. In one example, the discovery subsystem time scale may be measured in seconds, tens of seconds or minutes for static IoE devices1222,1224,1226,1228.

Discovery may be performed in one of a variety of available modes. In one example, the IoE devices1222,1224,1226,1228may be configured to support a pull mode, in which discovery operates based on messages provided in response to transmitted queries. In another example, the IoE devices1222,1224,1226,1228may be configured to support a push mode, in which the IoE devices1222,1224,1226,1228transmit advertisements periodically in accordance with a schedule or schedules defined or configured for the IoE devices1222,1224,1226,1228.

According to certain aspects, discovery may be performed in a multi-hop mode, whereby advertisements may be relayed by one or more IoE devices1222,1224,1226,1228in the subscriber domain1220. The discovery process may be configurable and flexible, permitting a range of payloads and ranges, which may be measured in the number of hops between IoE devices1222,1224,1226,1228in the subscriber domain1220.

With regard to the mesh waveform, a basic unit for discovery messages may include one or two resource blocks (RBs) transmitted in one millisecond periods. For an OFDM variant of RSMA, discovery signaling may include a preamble that may be similar to a sounding reference signal (SRS) preamble.

FIG. 13, with continued reference toFIG. 12, illustrates spectrum allocation1300for an IoE mesh and an example of a timing diagram1320corresponding to IoE mesh discovery processes. The spectrum may include frequencies1302assigned for WAN IoE uplink asynchronous RSMA, frequencies1304assigned for WAN IoE TDD mesh and burst access, and frequencies1308reserved for 5G nominal services. A guard band may separate the 5G nominal services frequencies1308from the mesh-related frequencies1302,1304. During the discovery period1310, the IoE devices1222,1224,1226,1228may listen1330to mesh signaling and may suspend listening1322to WAN signaling. The discovery period may be initiated by a triggering event, which may be periodic in nature.

The timing diagram1320corresponds to a discovery period1310. The duration, periodicity and other characteristics of the discovery period1310may be provided in a broadcast control message. Each node of an IoE mesh network subscriber domain1220, including the IoE devices1222,1224,1226,1228, may be temporally aligned in accordance with WAN synchronization signals1324and, in at least some instances, WAN parameters1326. For example, certain operations of the radio air interface may be temporally aligned in accordance with WAN synchronization signals. At some point during the discovery period1310, an IoE device1222,1224,1226,1228may transmit an advertisement1334. Each IoE device1222,1224,1226,1228may be configured to transmit its advertisement at a different time, or at some random time. The discovery process may benefit from use of the RSMA OFDM waveform, since the discovery period involves transmission and reception among IoE devices. The RSMA OFDM waveform may additionally incorporate a subset of resources onto which information can be spread.

Discovery may employ distributed resource allocation. Collision detection and handling may be implemented. In one example, a slotted ALOHA methodology may be followed, in which the strongest IoE device1222,1224,1226,1228prevails. Responses may be provided as a slave to the query. The process may include semi-persistent selection with collision detection.

After discovery, connections of the IoE mesh network1218may be configured. A connection may be established between two or more end nodes, where the end nodes may include the IoE devices1222,1224,1226,1228. In addition path selections may be configured for each of the IoE devices1222,1224,1226,1228. For WAN traffic, a single-hop or multi-hop path may be selected. The path is typically maintained by participating nodes. The integrity of the path may be checked and/or confirmed periodically. If path integrity is in question, if the path has failed, or if a better path is discovered, then the established path may be switched for a different path. According to certain aspects, Connectivity operates on a faster time scale than discovery.

FIG. 14is a diagram1400illustrating per-hop IoE mesh traffic transactions. Semi-persistent scheduling may be applied for stationary or low mobility nodes and synchronization within the mesh may be relaxed with respect to WAN-level synchronization.

According to certain aspects, traffic transactions occur within a series of windows1418. Each window1402may be sized to accommodate clock drifts and to allow sufficient time for the transaction interval1422in which synchronization and exchange of data may occur. In one example, each IoE device1222,1224,1226,1228may be configured with a schedule that identifies a scheduled time1406for the IoE device1222,1224,1226,1228to wake up and begin a listening period1404on the mesh network1218. Typically, the IoE device1222,1224,1226,1228may set or be configured to execute an early wakeup time1416such that clock drift can be accommodated. It will be appreciated that even with the early wakeup time1416, the IoE device1222,1224,1226,1228may wake up late, but typically within the margins permitted by the schedule. Aggregated clock drifts can be managed by timing advance information sent with an ACK1410, for example. WAN synchronization may be performed in some instances, including when overhead in power level is favorable for a WAN re-sync.

FIG. 15is a diagram1500illustrating an IoE network that may employ opportunistic UE relaying. IoE device may include sensors (S)1508,1510,1512. One or more sensors1510may have closed an uplink link to a base station1502. The sensors1508,1510,1512may be configured in a mesh network as disclosed herein. In some examples, the sensors1508,1510,1512may communicate opportunistically with the base station1502. For example, a first sensor1508may relay information through a first UE1504while a second sensor1512may relay information through a second UE1506, where the UEs1504,1506may be passing in proximity to the sensors1508,1512.

A power-efficient discovery mechanism may be employed for opportunistic UE relay. Discovery may be performed using narrowband communications. A UE1520may listen during a discovery window1526. Each sensor1522,1524may transmit data in a preconfigured or random slot during the discovery window1526. A UE1520that receives the transmission from one or more sensors1522,1524may be configured to transmit the received data instantaneously, or as soon as possible, and process ACKs on the uplink and downlink for the WAN and the one or more sensors1522,1524. In some instances, the UE1520may aggregate UL data from multiple sensors1522,1524before delivering the aggregated data to the WAN. Accordingly, there may be a delay between transmission of the uplink data by the sensors1522,1524and delivery to the WAN. Upon receipt of the aggregated data, the WAN may broadcast an ACK on the WAN downlink to the sensors1522,1524.

Opportunistic UE relaying may be associated with a security mechanism. A relay UE1504,1506and sensors1508,1512may authenticate each other using a network operator-signed embedded certificate. This security mechanism may incur significant processing and signaling overhead. Accordingly, in at least some instances, no security procedures are implemented between relay and sensor and other mechanisms may be employed to avoid potential vulnerability and/or damages.

With reference toFIG. 16, certain advantages and benefits may be attributed to systems, apparatus and methods adapted according to certain aspects disclosed herein. In one example, extended coverage and potentially more uniform power consumption may be provided across the network. In the example, a network may include a base station1602and two or more nodes1604,1606. The connection between a first node1604and the base station may be impaired by shadowing1608, such that the shadowing1608degrades the direct link between the first node1604and the base station1602by X dB relative to the second node1606. In this example, the first node1604may selectively communicate with the base station1602through the mesh network and the second node1606.

The graph1610illustrates network performance for various communication options. A first curve1612represents communication in which the second node1606operates as an aggregator, and the number of packets transmitted by the first node1604is dependent on the number of packets transmitted by the second node1606. A second curve1614represents communication in which includes mutual mesh-based communication and direct communication. Here, the nodes1604,1606can transmit their respective packets and each node1604,1606can relay for the other node1606,1604. A third curve1616represents communication in which each node1604,1606handles its own packets. The number of packets transmitted by each node1604,1606depends on the battery power and link quality associated with the node1604,1606.

In some examples, direct and mesh links may be managed by leveraging large downlink direct coverage. In one example, an advertising discovery period is provided and synchronization may be performed prior to the commencement of the discovery period. In some instances, centralized routing optimization updates may be provided.

In some examples, direct and mesh links may be partitioned across time, frequency, and/or space.

Certain aspects enable low power pre-scheduled multi-hop transactions to be configured and performed. Pre-scheduled link transmit and receive pairs may be allotted margin that accounts for timing drift.

In some examples, wakeup and transactions may be included in a resync message but with the pair only. Resync need not be performed with the network. Full resync with network may be performed only for discovery to save power consumption.

In some examples, an energy efficient routing protocol may be employed. Routing decisions may be made per packet or based on predefined scheduling that balances energy consumption across nodes.

Flexible Use of FDD Spectrum on Licensed Spectrum

In accordance with certain aspects disclosed herein, networks of IoE devices may participate in WAN and mesh network communications using licensed spectrum, where the direct and mesh networks of IoE devices are managed based on a flexible use of the FDD spectrum. FDD separates the uplink and downlink into two bands. In some later technologies, such as 4G LTE, device-to-device (D2D) communications may permit UEs to listen on a band designated for uplink transmission. Certain implementations may adapt PHY layer and/or MAC layer components to provide flexibility across both mobile devices and base stations. For example, certain mobile devices configured for D2D communications may be adapted to listen on bands designated for uplink transmission. Flexible use of the FDD spectrum may have application in wide area networks of low power devices, where high-power base stations may be configured to listen on downlink band for integrated access and for backhaul traffic transmitted in an over-the-air backhaul path. IoE devices, such as sensors, can listen on the uplink band, and/or may transmit on the downlink band for multi-hop mesh. The IoE device may be configured to use the downlink band when the IoE device is stationary. Flexible use of the FDD spectrum may enable and support mesh networks using licensed spectrum that are better managed than mesh networks that operate on unlicensed frequencies. The table1700inFIG. 17illustrates one example of PHY/MAC adaptation in a 5G network.

With reference toFIG. 18, and in accordance with certain aspects disclosed herein, downlink bands may be used by stationary IoE devices for transmitting mesh traffic. High power base stations1802,1804can listen on downlink bands for integrated access and to implement an over-the-air backhaul1814. The over-the-air backhaul1814may be used to extend wireless service when a remote base station1804is not connected by copper or optical backhaul. IoE devices1810,1812, including sensors can listen on an uplink band1830, and/or transmit on a downlink band1820to implement single-hop or multi-hop mesh networks. In some instances, the availability of the uplink band1830, and/or the downlink band1820may be conditioned on the IoE devices1808,1812being stationary. The use of licensed spectrum can provide better management of mesh networks than available in conventional mesh networks that use unlicensed frequencies.

The networking environment illustrated inFIG. 18operates using flexible FDD, and may be referred to as an “edgeless Internet of everything.” In conventional networks, sensors and machine communications underutilize spectrum assigned or used to implement a network of sensors. Low payload and low duty cycle from single battery charge devices contribute to the limited network use, particularly where uplink communications can drain sensor batteries.

The use of flexible FDD for wide-area IoE networks, in accordance with certain aspects disclosed herein, can enable cell-to-cell transmission for multi-hop relay on FDD downlink bands. The downlink spectrum is typically underutilized, and the use of the downlink spectrum for IoE networks permits fast deployment with chokepoints to be backhauled later as needed. Flexible application of FDD spectrum may enable IoE-to-IoE transmission for multi-hop relay on FDD uplink and/or FDD downlink, and may leverage the underutilized downlink spectrum among IoE nodes that are stationary.

FIG. 19illustrates examples1900,1940of radio configuration for flexible FDD. An existing radio front-end may be adapted to enable flexible FDD. The adapted radio front-end may exploit the lack of simultaneous transmission or reception across both uplink and downlink bands. Other radio configurations and additional approaches may be used to support of Tx/Rx on UL band only or on the DL band only.

FIG. 19includes a first example1900of a radio configuration for flexible FDD that operates in full-duplex mode. A modem1902may include transmit1912and receive1914components that cooperate with a transceiver. A dual-pole, double throw switch (X-Switch)1906may be provided to configure FDD band1918,1920usage.

FIG. 19includes a second example1940of a radio configuration for flexible FDD that operates in half-duplex mode. Here the X-Switch1906and FDD Duplexer may be substituted with a single-pole, double throw switch1942.

In some examples, FDD Uplink and/or FDD Downlink bands are enabled for a multi-hop mesh. Nodes in the multi-hop mesh may include base stations and/or IoE devices. FDD Uplink and/or FDD Downlink bands may be used to extend coverage as needed when FDD spectrum is underutilized.

In some examples, base stations support combined Tx and Rx only on the FDD Downlink Band. In some instances, full Tx/Rx may be provided on FDD Uplink Band when Tx Power is within certain effective isotropic radiated power (EIRP) limits.

In some examples, IoE devices have Tx/Rx on FDD Uplink Band. Full Tx/Rx may be provided on FDD Downlink Band when IoE devices are stationary, thereby permitting Tx.

In some examples, IoE devices can use converged radio with small front-end modifications.

FIG. 20is a conceptual diagram2000illustrating a simplified example of a hardware implementation for an apparatus employing a processing circuit2002that may be configured to perform one or more functions disclosed herein. In accordance with various aspects of the disclosure, an element, or any portion of an element, or any combination of elements as disclosed herein may be implemented using the processing circuit2002. The processing circuit2002may include one or more processors2004that are controlled by some combination of hardware and software modules. Hardware modules may include one or more analog or digital circuits that may perform some combination of logic functions and signal processing. Software modules may include blocks of code that may be used to configure and/or control operations of a processor2004in the performance of one or more functions. Examples of processors2004include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, sequencers, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality described throughout this disclosure. The one or more processors2004may include specialized processors that perform specific functions, and that may be configured, augmented or controlled by one of the software modules2016. The one or more processors2004may be configured through a combination of software modules2016loaded during initialization, and further configured by loading or unloading one or more software modules2016during operation.

In the illustrated example, the processing circuit2002may be implemented with a bus architecture, represented generally by the bus2010. The bus2010may include any number of interconnecting buses and bridges depending on the specific application of the processing circuit2002and the overall design constraints. The bus2010links together various circuits including the one or more processors2004, and storage2006. Storage2006may include memory devices and mass storage devices, and may be referred to herein as computer-readable media and/or processor-readable media. The bus2010may also link various other circuits such as timing sources, timers, peripherals, voltage regulators, and power management circuits. A bus interface2008may provide an interface between the bus2010and one or more transceivers2012. A transceiver2012may be provided for each networking technology supported by the processing circuit. In some instances, multiple networking technologies may share some or all of the circuitry or processing modules found in a transceiver2012. Each transceiver2012provides a means for communicating with various other apparatus over a transmission medium. Depending upon the nature of the apparatus, a user interface2018(e.g., keypad, display, speaker, microphone, joystick) may also be provided, and may be communicatively coupled to the bus2010directly or through the bus interface2008.

A processor2004may be responsible for managing the bus2010and for general processing that may include the execution of software stored in a computer-readable medium that may include the storage2006. In this respect, the processing circuit2002, including the processor2004, may be used to implement any of the methods, functions and techniques disclosed herein. The storage2006may be used for storing data that is manipulated by the processor2004when executing software, and the software may be configured to implement any one of the methods disclosed herein.

One or more processors2004in the processing circuit2002may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, algorithms, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. The software may reside in computer-readable form in the storage2006or in an external computer readable medium. The external computer-readable medium and/or storage2006may include a non-transitory computer-readable medium. A non-transitory computer-readable medium includes, by way of example, a magnetic storage device (e.g., hard disk, floppy disk, magnetic strip), an optical disk (e.g., a compact disc (CD) or a digital versatile disc (DVD)), a smart card, a flash memory device (e.g., a “flash drive,” a card, a stick, or a key drive), a random access memory (RAM), a read only memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM), an electrically erasable PROM (EEPROM), a register, a removable disk, and any other suitable medium for storing software and/or instructions that may be accessed and read by a computer. The computer-readable medium and/or storage2006may also include, by way of example, a carrier wave, a transmission line, and any other suitable medium for transmitting software and/or instructions that may be accessed and read by a computer. Computer-readable medium and/or the storage2006may reside in the processing circuit2002, in the processor2004, external to the processing circuit2002, or be distributed across multiple entities including the processing circuit2002. The computer-readable medium and/or storage2006may be embodied in a computer program product. By way of example, a computer program product may include a computer-readable medium in packaging materials. Those skilled in the art will recognize how best to implement the described functionality presented throughout this disclosure depending on the particular application and the overall design constraints imposed on the overall system.

The storage2006may maintain software maintained and/or organized in loadable code segments, modules, applications, programs, etc., which may be referred to herein as software modules2016. Each of the software modules2016may include instructions and data that, when installed or loaded on the processing circuit2002and executed by the one or more processors2004, contribute to a run-time image2014that controls the operation of the one or more processors2004. When executed, certain instructions may cause the processing circuit2002to perform functions in accordance with certain methods, algorithms and processes described herein.

Some of the software modules2016may be loaded during initialization of the processing circuit2002, and these software modules2016may configure the processing circuit2002to enable performance of the various functions disclosed herein. For example, some software modules2016may configure internal devices and/or logic circuits2022of the processor2004, and may manage access to external devices such as the transceiver2012, the bus interface2008, the user interface2018, timers, mathematical coprocessors, and so on. The software modules2016may include a control program and/or an operating system that interacts with interrupt handlers and device drivers, and that controls access to various resources provided by the processing circuit2002. The resources may include memory, processing time, access to the transceiver2012, the user interface2018, and so on.

One or more processors2004of the processing circuit2002may be multifunctional, whereby some of the software modules2016are loaded and configured to perform different functions or different instances of the same function. The one or more processors2004may additionally be adapted to manage background tasks initiated in response to inputs from the user interface2018, the transceiver2012, and device drivers, for example. To support the performance of multiple functions, the one or more processors2004may be configured to provide a multitasking environment, whereby each of a plurality of functions is implemented as a set of tasks serviced by the one or more processors2004as needed or desired. In one example, the multitasking environment may be implemented using a timesharing program2020that passes control of a processor2004between different tasks, whereby each task returns control of the one or more processors2004to the timesharing program2020upon completion of any outstanding operations and/or in response to an input such as an interrupt. When a task has control of the one or more processors2004, the processing circuit is effectively specialized for the purposes addressed by the function associated with the controlling task. The timesharing program2020may include an operating system, a main loop that transfers control on a round-robin basis, a function that allocates control of the one or more processors2004in accordance with a prioritization of the functions, and/or an interrupt driven main loop that responds to external events by providing control of the one or more processors2004to a handling function.

The following flowcharts illustrate methods and processes performed or operative on network elements adapted or configured in accordance with certain aspects disclosed herein. The methods and processes may be implemented in any suitable network technology, including 3G, 4G, and 5G technologies, to name but a few. Accordingly, the claims are not restricted to a single network technology. In this regard, a reference to a “UE” may be understood to refer also to a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. A reference to an “eNodeB” may be understood to refer to a base station, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set, an extended service set, or some other suitable terminology. A reference to an MME may refer also to an entity that serves as an authenticator in the serving network and/or a primary service delivery node such as a Mobile Switching Center, for example. A reference to the HSS may refer also to a database that contains user-related and subscriber-related information, provides support functions in mobility management, call and session setup, and/or user authentication and access authorization, including, for example, a Home Location Register (HLR), Authentication Centre (AuC) and/or an authentication, authorization, and accounting (AAA) server.

FIG. 21is a flow chart2100of a method of wireless communication.

At block2102, a first device may receive WAN scheduling information from downlink signals received at a first device from an entity of the WAN when the first device is configured for a first mode of communication.

At block2104, the first device may determine a mesh network schedule based on the WAN scheduling information. Operations of the first device may be temporally aligned with WAN synchronization signals. Use of mesh network resources may be coordinated based on the WAN scheduling information.

At block2106, a current mode of communication may be determined. In one example, the current mode of communication may be determined based on scheduling information received from an entity of a WAN. One or more modes of communication may be enabled at idle times in the scheduling information. Two modes of communication are illustrated in the flow chart2100. If a first mode of communication is selected, then the method continues at block2108. If the second mode of communication is selected, then the method continues at block2110.

At block2108, the radio may be operated in accordance with the first mode of communication, and may transmit data wirelessly from the first device at a first power level over time-domain resources to an entity in a WAN.

At block2110, the radio may be operated in accordance with the second mode of communication, and a second power level may be selected for use in the second mode of communication. The second power level may be selected to be less than a power level calculated to cause the entity in the WAN to ignore data transmissions by the first device in the second mode of communication if received by the entity in the WAN.

At block2112, the radio may transmit data wirelessly from the first device at a second power level lower than the first power level over frequency-domain resources to a second device in accordance with the mesh network schedule.

In some examples, the second power level may be selected to be less than a threshold power level. The threshold power level may be calculated to cause the entity in the WAN to ignore data transmissions by the first device in the second mode of operation if received by the entity in the WAN. In one example, the threshold power level may be calculated as the minimum transmission power level that corresponds to a received power level that is detectable at a scheduling entity, base station or the like. In another example, the threshold power level may be calculated as the minimum transmission power that corresponds to a received power level for signals that are not ignored or filtered by a scheduling entity, base station or the like. In another example, signals transmitted from the first device to the second device at the second power level may be detected by a scheduling entity or other entity in the WAN. In another example, a scheduling entity or other entity in the WAN that detects signals transmitted from the first device to the second device at the second power level may treat such signals as interfering signals, and may filter such interfering signals.

In one example, the first device may exit a sleep mode of operation, monitor the mesh network for messages, receive an advertisement from a third device coupled to the mesh network, and configure a path to the entity of the WAN based on the advertisement. The first device may determine a plurality of paths between the entity of the WAN and the second device, and select a preferred path from the plurality of paths for routing messages from the second device to the entity of the WAN. The preferred path may be selected on a per packet basis or based on a predefined schedule that balances energy consumption across nodes of the mesh network. The first device may wake in accordance with the mesh network schedule. The mesh network schedule may define link transmit and receive pairs. The link transmit and receive pairs may be allotted timing margin to account for timing drift between two or more mesh network devices.

In some instances, the first device may execute a pre-scheduled multi-hop transaction with the entity of the WAN.

FIG. 22is a flow chart2200of a method of wireless communication. The method may be performed by a first IoE device connected to a mesh network.

At block2202, in a first mode of operation, the first IoE device may configure a radio of the first IoE device to operate in accordance with a first variant of a RSMA technology in a first mode of operation. The radio may be configured to spread data over time-domain resources in the first mode of operation.

At block2204, the first IoE device may communicate wirelessly from the first IoE device to a base station of a wireless access network when the radio is configured to operate in accordance with the first variant of the RSMA technology.

At block2206, and in a second mode of operation, the first IoE device may configure the radio of the first IoE device to operate in accordance with a second variant of the radio access technology. The radio may be configured to spread data over frequency-domain resources in the second mode of operation.

At block2208, the first IoE device may communicate wirelessly with a second IoE device in a mesh network when the radio is configured to operate in accordance with the second variant of the RSMA technology. The first IoE device and the second IoE device may communicate wirelessly using low-power radio frequency transmitters.

In some instances, and in a third mode of operation, the radio of the first IoE device may be configured to operate in accordance with a third variant of the RSMA technology. The radio may be configured to spread data over a combination of time-domain resources and frequency-domain resources in the third mode of operation.

In one example, the first IoE device may communicate wirelessly with the base station when the radio is configured to operate in accordance with the third variant of the RSMA technology. The first IoE device may communicate wirelessly with the second IoE device when the radio is configured to operate in accordance with the third variant of the RSMA technology.

In another example, communicating wirelessly with the second IoE device may include receiving data from the second IoE device while the radio is operated in the second mode of operation, reconfiguring the radio of the first IoE device to operate in accordance with the first variant of the RSMA technology, and transmitting the data to the base station using the first variant of the RSMA technology.

In another example, data transmitted by a plurality of devices over the mesh network may be aggregated to obtain aggregated data. The aggregated data may be relayed to the base station using the first variant of the RSMA technology.

In some instances, the first variant of the RSMA technology is a single-carrier RSMA technology, and the second variant of the RSMA technology is a multicarrier OFDM RSMA. The first variant of the RSMA technology and the second variant of the RSMA technology may employ a same waveform or a related scaled numerology.

In some instances, reconfiguring the radio of the first IoE device to operate in accordance with a second variant of the RSMA technology includes configuring the radio with a simplified decoder version for an error-correction code used with the first variant of the RSMA technology. The RSMA access technology may include a configurable combination of scrambling, spreading, and interleaving. The RSMA access technology may employ time-division duplexed pilot and control signals.

FIG. 23is a diagram illustrating an example of a hardware implementation for an apparatus2300employing a processing circuit2302. The processing circuit typically has a processor2316that may include one or more of a microprocessor, microcontroller, digital signal processor, a sequencer and a state machine. The processing circuit2302may be implemented with a bus architecture, represented generally by the bus2320. The bus2320may include any number of interconnecting buses and bridges depending on the specific application of the processing circuit2302and the overall design constraints. The bus2320links together various circuits including one or more processors and/or hardware modules, represented by the processor2316, the modules or circuits2304,2306,2308, and2310, a radio air interface2312that may be include or cooperate with an RF transmitter coupled to an antenna2314, and the computer-readable storage medium2318. The bus2320may also link various other circuits such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art, and therefore, will not be described any further.

The processor2316is responsible for general processing, including the execution of software stored on the computer-readable storage medium2318. The software, when executed by the processor2316, causes the processing circuit2302to perform the various functions described supra for any particular apparatus. The computer-readable storage medium2318may also be used for storing data that is manipulated by the processor2316when executing software, including data decoded from symbols received through the antenna2314. The processing circuit2302further includes at least one of the modules2304,2306,2308, and2310. The modules2304,2306,2308, and2310may be software modules running in the processor2316, resident/stored in the computer-readable storage medium2318, one or more hardware modules coupled to the processor2316, or some combination thereof. The modules2304,2306,2308, and/or2310may include microcontroller instructions, state machine configuration parameters, or some combination thereof.

In one configuration, the apparatus2300for wireless communication includes modules and/or circuits2304for configuring the radio air interface2312, including logic configured to select an output of the radio air interface2312from a plurality of signals including a single-carrier encoded data stream and an OFDM modulated data stream. The apparatus2300may include modules and/or circuits2306for encoding data in accordance with a single-carrier RSMA coding scheme. The apparatus2300may include modules and/or circuits2308for modulating the single-carrier encoded data stream to obtain the OFDM modulated data stream.

In another configuration, the apparatus2300for wireless communication includes a radio air interface2312, modules and/or circuits2304for configuring a radio air interface, where the radio air interface may be configured for a first mode of communication and for a second mode of communication. The apparatus2300may include modules and/or circuits2310for determining WAN timing from downlink signals received from a base station when the radio air interface is configured for the first mode of communication, and for configuring mesh network timing. The means for configuring mesh network timing may be adapted to configure mesh network timing based on the WAN timing. The apparatus2300may include modules, circuits, and/or devices2306,2308,2312,2314for communicating wirelessly with a mesh device in accordance with the mesh network timing when the radio air interface is configured for the second mode of communication. The apparatus and the mesh device communicate at power levels below a power level threshold selected to cause the base station to ignore transmissions between the apparatus and the mesh device.

In another configuration, the apparatus2300may include modules and/or circuits2312,2314for receiving downlink signals at a first device, where the downlink signals are transmitted on a downlink frequency of a licensed wireless access network. The apparatus2300may include modules and/or circuits2306,2308,2312,2314for communicating on wireless networks, including the radio air interface2312configured to transmit a first message to a second device on the downlink frequency, where the first message is unrelated to the licensed wireless access network. The apparatus and the second device may communicate over a mesh network at power levels below a power level threshold selected to cause the base station to ignore transmissions between the first device and the second device.