Body area network with binary wireless backscatter device

Abstract

A body area network with a binary wireless backscatter device is provided. Configuring and utilizing a body area network (BAN) are provided. In the configuration phase, a configuration message for scheduling the plurality of backscatter devices is transmitted such that during the data collection phase, each of the plurality of backscatter devices is configured to transmit in an individually allocated slot. In a data collection phase, a data collector device receives, from a plurality of backscatter devices, sensor data messages including sensor data from the backscatter devices, the sensor data messages being scheduled according to a configuration phase.

Description

Technical Field

[0001] Aspects of the present disclosure relate to the configuration and operation of a body area network for capturing sensor data about a user. Background Art

[0002] Body area networks involve communication between at least one body-worn device and other body-worn devices or external devices. Most applications fall into the categories of personalized applications or medical applications. Personalized applications may include health, wellness, fitness, sports, etc., while medical applications have more stringent requirements in terms of data security, interoperability, and performance. To meet the body area network requirements for medical applications, there are several standardization efforts, including the Institute of Electrical and Electronics Engineers (IEEE) 802.15.6 standard. On the other hand, for personalized applications, there are no specific standards. Summary of the invention

[0003] In one or more illustrative examples, a method for configuring and utilizing a body area network (BAN) includes: during a configuration phase, sending a configuration message for scheduling multiple backscatter devices so that during a data collection phase, each of the multiple backscatter devices is configured to backscatter from an excitation signal in a separately assigned time slot; and during the data collection phase, receiving sensor data messages including sensor data from the backscatter devices from the multiple backscatter devices to a data collector device, the sensor data messages being scheduled according to the configuration phase.

[0004] In one or more illustrative examples, a system for configuring and utilizing a BAN includes a plurality of backscatter devices and a data collector device. During a configuration phase, the plurality of backscatter devices are configured to receive a configuration message for scheduling transmissions of the plurality of backscatter devices, such that during a data collection phase, each of the plurality of backscatter devices is configured to transmit in a separately assigned time slot. During a data collection phase, the data collector device is configured to receive sensor data messages from the plurality of backscatter devices including sensor data from the backscatter devices, the sensor data messages being scheduled according to the configuration phase. BRIEF DESCRIPTION OF THE DRAWINGS

[0005] Figure 1 An example of an application is shown, in which a person wears several sensors on the body;

[0006] Figure 2A An example of a monostatic backscattering configuration is shown;

[0007] Figure 2B An example of a two-state backscatter configuration is shown;

[0008] Figure 3AA first body area network architecture is shown, wherein a backscatter device, a data collector device, and an excitation device are located on the body;

[0009] Figure 3B A second body area network architecture is shown, wherein the backscatter device and the excitation device are on the body, and the data collector device is an external device;

[0010] Figure 3C A third body area network architecture is shown, wherein the backscatter device and the data collector device are on the body, and the excitation device is an external device;

[0011] Figure 3D Other aspects of an example backscatter device are shown;

[0012] Figure 3E Other aspects of an example data collector device are shown;

[0013] Figure 3F Other aspects of an example excitation device are shown;

[0014] Figure 3G Other aspects of an example general purpose sensor device are shown;

[0015] Figure 4 An example mechanism for backscatter communications is shown;

[0016] Figure 5 An example of a predetermined periodic wake-up of a backscatter device is shown;

[0017] Figure 6 An example of optimized periodic wake-up using a channel arbitration technique is shown;

[0018] Fig. 7A An example of a configuration beacon message (Beacon C) is shown;

[0019] Figure 7B An example of a Configure Sensor (CS) message is shown;

[0020] Figure 7C An example of a Configure Backscatter (CB) message for a backscatter device is shown;

[0021] Fig.7D An example of a data period beacon message (Beacon D) is shown;

[0022] Fig. 7E An example of a sensor data message (DS) is shown;

[0023] Figure 7F An example of a backscatter data message (DB) is shown;

[0024] Figure 7GAn example of a periodic message schedule for data transfer in a pipeline-less single radio receiver architecture is shown;

[0025] Figure 7H An example of periodic message scheduling for data transfer in a pipelining-enabled two separate receiver / single receiver device with two radios architecture is shown;

[0026] Fig. 8A An example of a configuration beacon C message for an architecture including data aggregation is shown;

[0027] Figure 8B An example of a CS message including an architecture for data aggregation is shown;

[0028] Figure 8C An example of a CB for a backscatter device including an architecture for data aggregation is shown;

[0029] Fig.8D An example of a beacon D including an architecture for data aggregation is shown;

[0030] Fig. 8E An example of a DS including an architecture for data aggregation is shown;

[0031] Figure 8F An example of a backscatter data message (DB) of an architecture including data aggregation is shown;

[0032] Figure 8G An example of periodic message scheduling for data delivery in a pipeline-enabled single-receiver architecture with data aggregation is shown;

[0033] Fig. 9 An example of periodic message scheduling for data transfer for an architecture including data aggregation is shown; and

[0034] Fig.10 An example of a computing device for use in a body area network architecture is shown. DETAILED DESCRIPTION

[0035] As required, detailed embodiments of the present invention are disclosed herein; however, it should be understood that the disclosed embodiments are merely examples of the present invention, which may be embodied in various alternative forms. These figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, the specific structural and functional details disclosed herein should not be interpreted as limiting, but merely as a representative basis for teaching those skilled in the art to adopt the present invention in various ways.

[0036] Various aspects of the present disclosure relate to providing low power wireless connectivity between a body worn device and a non-body worn device that communicates with the body worn device. Various applications such as health, wellness, fitness, sports, etc. require a user to wear one or more sensor devices on the body for providing sensor data. The sensor data can be used to measure and optimize attributes such as posture correction, exercise monitoring / recommendations, sports performance, etc.

[0037] Body-worn sensors are often battery-powered for the best user experience, and in some cases, the application itself also needs to be battery-powered. Since body-worn devices are often battery-powered, the trade-off between power consumption and data rate / latency remains a key challenge. Therefore, low power consumption is very important, while meeting data rate, latency, and interoperability requirements is also very important.

[0038] Assuming that most applications require short-range communications, in the present disclosure, sensors with wireless backscatter communication capabilities are used. Such devices can result in an order of magnitude of power savings in wireless communications compared to transceiver-based solutions. The management of several backscatter sensors and supporting the quality of service requirements of applications is important. Other aspects of the present disclosure propose methods to support these requirements.

[0039] Figure 1 Represents an application in which a user wears several sensors 102 on the body. These sensors 102 can be placed directly on the human body (e.g., with or without a housing) or can be embedded in a body-worn object (such as clothing, shoes, etc.). As shown, the user wears a headband sensor 102A on his head. The user also wears in-ear sensors 102B, 102C in either ear. The user also has a spine sensor 102D located on his spine and a chest sensor 102E located on his chest. The user also has wrist sensors 102F, 102G located on each wrist and ankle sensors 102H, 102I located on either ankle. The user also has a shoe sensor 102J located in his shoe. It should be noted that these sensors 102 are merely examples, and more, fewer, or differently positioned sensors 102 may be used. At least one of these sensors 102 may utilize backscatter communication. Backscatter communication may be monomorphic, bistatic, or interoperable.

[0040] Figure 2AAn example 200A of a single-state backscatter configuration is shown. This configuration includes two main components: a transceiver device 202, represented here as Tx / Rx, and a tag 204. The transceiver device 202 can operate as a carrier transmitter and can provide a radio frequency (RF) excitation signal 206 to activate the tag 204. The tag 204 can modulate the received excitation signal 206 to provide a backscatter signal 208 that is reflected back from the tag 204. The transceiver device 202 can then receive the backscatter signal 208.

[0041] Figure 2B An example 200B of a two-state backscatter configuration is shown. This configuration includes three main components: a transmitter device 210, represented here as Tx, a tag 204, and a receiver device 212, represented here as Rx. In such an example, the transmitter and receiver functions of the transceiver device 202 are separated. Here, the transmitter device 210 can operate as a carrier transmitter and can provide an excitation signal 206 to activate the tag 204. The excitation signal 206 can be a continuous wave (CW) or a modulated signal of a standard technology such as Bluetooth Low Energy (BLE), Wi-Fi, 802.15.4, or any other proprietary wireless protocol. The tag 204 can modulate the excitation signal 206 to provide a backscatter signal 208 reflected back from the tag 204. The receiver device 212 can then receive the backscatter signal 208.

[0042] Backscatter devices can be active or passive. Active devices can have their own power source and can collect sensor data as needed. On the other hand, passive sensors can derive their power from the excitation signal 206 and therefore collect data only when such an excitation signal 206 is present. Single device backscatter has been proposed for body implants, edible pills, and body sensors. Instead of RF energy, in-body devices or implants can also use magnetic energy (e.g., inductive coupling) for both data and power transfer.

[0043] During a backscatter event, RF data transfer can be performed solely via backscatter and can therefore differ from more traditional passive radio frequency identification (RFID) based solutions, which can also transfer power and energy. Another difference is that the transmitter and receiver do not need to be co-located as with traditional RFID (active or passive). This lack of co-location may require additional power-efficient communication mechanisms between the transmitter and receiver to achieve time synchronization and configure system / protocol parameters.

[0044] The disclosed methods focus on backscatter node performance and system capacity. In general, harvesting energy from the ambient environment may not be sufficient for high data rate applications, so dedicated methods can be used instead. Among the dedicated methods, non-radiative inductive coupling (e.g., within a few centimeters) and non-radiative magnetic resonance coupling (e.g., within tens of centimeters) can be considered safe for human tissue, which is an important consideration for body-worn devices. Given that the charging range of these safe power harvesting methods is insufficient for certain intended use cases, the focus can instead be on optimizing data transfer and system capacity while optimizing power-efficient communications.

[0045] The sensor 102 can be powered by a power source such as a supercapacitor or a battery. In some cases, the sensor 102 can harvest energy from environmental conditions. It should be noted that various wireless charging methods can be utilized during use of the sensor 102 device on the human body. After use, the sensor 102 can be recharged or the battery replaced.

[0046] Figures 3A-3C An example of a BAN 300 system architecture is shown. Figure 3A A first body area network 300A architecture is shown in which backscatter devices 302A-D, a data collector device 304, and an excitation device 306 are located on the body. Figure 3B A second body area network 300B architecture is shown, where the backscatter devices 302A-E and the excitation device 306 are on the body, while the data collector device 304 is an external device. Figure 3C A third body area network 300C architecture is shown, where the backscatter devices 302A-E and the data collector device 304 are on the body, while the excitation device 306 is an external device.

[0047] Figure 3D Other aspects of an example backscatter device 302 are shown. As shown, the backscatter device 302 may include at least one sensor 102, a microcontroller 308 including a microprocessor, memory, and I / O to connect to other peripherals, a power storage device 310, an antenna switching circuit 314, and (optionally) a wake-up circuit 315. The sensor 102 may include an inertial measurement unit (IMU) (e.g., an accelerometer or gyroscope), a pressure sensor, an optical sensor, etc.

[0048] Microcontroller 308 may be used to generate baseband signals and process sensor data. In some examples, backscatter device 302 may include a separate custom application specific integrated circuit (ASIC) for generating baseband signals. Additionally, sensor 102, microcontroller 308, and other components of backscatter device 302 may be separate chips or packaged in a module.

[0049] Backscatter device 302 may be powered by power storage device 310. Power storage device 310 may be a regular battery, a supercapacitor, or a rechargeable battery. For rechargeable power options, the device may additionally utilize wired, wireless or ambient charging, harvesting power from kinetic energy, and the like.

[0050] Backscatter device 302 may optionally include a wake-up circuit 315 configured to allow backscatter device 302 to effectively receive and understand a wake-up signal. Backscatter device 302 may include an envelope detector so that backscatter device 302 wakes up only when a signal above a given threshold is received. Simple on-off keying may be used to provide the wake-up signal. One such implementation utilizes a Manchester-encoded 125kHz waveform.

[0051] The backscatter device 302 may also include a pattern correlator to wake up only when a message is addressed to a transmit-only node by utilizing a unique pattern of each backscatter device 302. The backscatter device 302 may also employ machine learning and advanced signal processing techniques to directly process application-specific data derived from the sensor 102, such as step counting, personalized fitness tracking, swimming analysis, continuous position tracking of pedestrians, etc. The backscatter device 302 may also include additional human-machine interface (HMI) components, such as light emitting diodes (LEDs), tactile devices, etc., for providing user feedback.

[0052] The antenna switching circuit 314 can allow the backscatter device 302 to switch between receiving a wake-up message and modulating the excitation signal 206. A simple on-off keying can be used to provide the wake-up signal. One such implementation utilizes a Manchester-encoded 125kHz waveform. The transmitted data packet signal can be of standard technology, such as BLE, Wi-Fi, IEEE802.15.4, 5G reduced capacity, or any other proprietary wireless protocol. The backscatter device 302 can optionally utilize a wake-up circuit including at least an envelope detector to wake up only when the signal is above a given threshold. The backscatter device 302 can also include a pattern correlator to wake up only when a message is addressed to a backscatter node by utilizing a unique pattern of each backscatter device 302.

[0053] When the antenna switching circuit 314 is in the wake-up mode, the backscatter device 302 can be configured to listen for a wake-up message. When the antenna switching circuit 314 is in the transmit mode, the backscatter device 302 can adjust the received excitation signal 206 to generate a backscatter signal 208 to transmit information. The backscatter device 302 can also use machine learning and advanced signal processing techniques to directly process application-specific data derived from the sensor 102, such as step counting, personalized fitness tracking, swimming analysis, continuous position tracking of pedestrians, etc. The backscatter device 302 can also include additional HMI components, such as LEDs, tactile devices, etc., for providing user feedback.

[0054] Figure 3E Other aspects of an example data collector device 304 are shown. Devices in a BAN 300 may assume various roles. A BAN 300 with backscatter devices 302 includes at least three main devices: at least one backscatter device 302, a data collector device 304 configured as a receiver of transmissions from a sensor 102, and an excitation device 306.

[0055] In some examples, the data collector device 304 can be placed on the body, but in other examples, the data collector device 304 can be off the body. The data collector device 304 can be used to receive and aggregate data from multiple backscatter devices 302. The data collector device 304 can include a wireless receiver 316 to receive the transmitted backscatter data. In some implementations, the wireless receiver 316 can be a transceiver 320 that has a transmission capability in addition to a receiving capability. The wireless receiver 316 can use the same wireless technology as the backscatter device 302 and / or other on-body universal sensor devices 307 using the transceiver 320. In addition to the wireless receiver 316 using the same wireless technology as the backscatter device 302, the wireless receiver 316 can also support additional wireless technologies, such as Wi-Fi, BLE, IEEE 802.15.4, cellular, etc., to allow the data collector device 304 to communicate with additional HMI devices 324 (such as a television, display screen, or tablet computing device).

[0056] For an optimal or immersive user experience, the data collector device 304 may include an HMI 318 to provide user feedback. The data collector device 304 may also include a microcontroller 308 to aggregate and process sensor data for display or forwarding to an HMI device 324. The data collector device 304 itself may be battery powered and may employ a rechargeable battery 322 that may be charged by wire or wirelessly.

[0057] Figure 3F-3GOther aspects of an example excitation device 306 and an example universal sensor device 307 are shown together. Similar to the backscatter device 302, the excitation device 306 can include a microcontroller 308 including a microprocessor, memory, and I / O connected to other peripherals, and a power storage device 310. The excitation device 306 can be configured to provide the excitation signal 206.

[0058] In some examples, generic sensor device 307 may include components of stimulus device 306 and may also be configured to include transceiver 320 to provide a sensor signal based on at least one of its sensors 102 (if so equipped).

[0059] The HMI device 324 may also be configured to send the stimulus signal 206. In other examples, the HMI device 324 or the data collector device 304 may also be configured to generate the stimulus signal 206 and / or generate a wake-up signal to configure the device.

[0060] BAN 300 may collectively enable recording and / or analysis of data from sensors 102 for various applications. As some non-limiting examples, these applications may include: body motion capture applications for orientation tracking (such as yoga) or curvature tracking (such as running); posture correction and balance; daily activities such as walking, running, cycling, sleeping, etc.; fitness activities such as (full body) training, exercise, etc.; health activities such as yoga, dancing, meditation, etc.; sports activities such as football, boxing, basketball, cricket, badminton, tennis, table tennis, golf swing, swimming, etc.; and / or custom gestures such as pet activities (scratching), accessories (rings), skateboards, smartphone photos / QR code scanning, etc.

[0061] Figure 4 An example mechanism 400 for backscatter communication is shown. As shown, the backscatter device 302 can transmit in the presence of an excitation signal 206. The excitation signal 206 can be a CW signal with a given center frequency, or it can be a modulated signal of a standard RF technology, such as Bluetooth low energy, an 802.15.4-based protocol (e.g., ZigBee, Thread, etc.), Wi-Fi, etc. The backscatter signal 208 is one of these standard wireless technologies, such as a modulated signal based on BLE, Wi-Fi, 802.15.4, or any proprietary. The backscatter signal 208 does not have any frequency radio component required for carrier generation and is therefore dependent on the excitation signal 206. However, this design also results in low power operation because the backscatter device 302 modulates the excitation signal 206 as required by the receiver device 212.

[0062] As shown, a transmitter device 210 broadcasts an excitation signal 206. The excitation signal 206 is received by a receiver device 212. In addition, the excitation signal 206 excites the tag 204, which thereby generates a backscatter signal 208. The excitation signal 206 can be any wireless signal generated using a set of known codewords from a fixed codebook. For example, Bluetooth uses frequency shift keying (FSK) modulation, and there are two codewords in its codebook: it sends a tone on a frequency to send data one, and sends zero on a different frequency. Similarly, WiFi and ZigBee also have a limited set of codewords that vary in a combination of phase, amplitude, or frequency. In order to perform codeword translation, the tag 204 transforms the excitation signal 206 codeword into another valid codeword in the same codebook during backscattering. This is accomplished by modifying one or more of the amplitude, phase, and frequency of the excitation signal 206. The specific translation depends on the data that the tag 204 wants to transmit and the type of the excitation signal 206. Because the codeword in the backscatter signal is a valid codeword from the same codebook as the original excitation signal 206, the backscatter signal 208 can be similarly received by the receiver device 212. Then, both the excitation signal 206 and the backscatter signal 208 are provided to the tag decoder 404. The tag decoder 404 can determine the backscatter signal 208 based on its knowledge of the excitation signal 206.

[0063] Figure 4 The mechanism 400 shown in is acceptable for a single backscatter device 302 in a BAN 300 environment, such as in the case of a medical implant with limited range. However, in a BAN 300 with several backscatter devices 302 in the environment (either on a single user, or on multiple users in close proximity), then all of the backscatter devices 302 in the vicinity may respond to the stimulus signal 206 together. In order to decrypt the individual messages from the backscatter devices 302, the BAN 300 may, for example, shift those corresponding responses to different channels, which will also require many receivers on different channels to receive those messages. This approach increases costs and at the same time limits the system capacity (e.g., limiting the total number of backscatter devices 302 in the vicinity) to the maximum number of channels to which the modulated signal can be shifted. At the same time, if the receiver jumps between different channels to receive messages from these backscatter devices 302, then the energy of the backscatter devices 302 may be wasted on messages that are not received. In addition, since these backscatter devices 302 may lack receivers, the backscatter devices 302 may not be able to receive feedback and may continue to transmit regardless of whether their messages are received. Therefore, additional methods may be utilized to arbitrate wireless channels and avoid wasting energy of the backscatter device 302 .

[0064] refer to Figure 5, showing an example of a predetermined periodic wake-up of the backscatter device 302. Figure 5 The illustrated example assumes that the excitation signal 206 is constant at the beginning of the process, e.g., until the data collector device 304 synchronizes with the transmit pattern of the backscatter device 302. As shown, the backscatter device 302 may transmit sensor data via backscatter in response to the expiration of a timer for transmission.

[0065] For the periodic transmission method, each backscatter device 302 can collect sensor data during a predetermined time period, such that when the timer expires, the backscatter device 302 transmits the sensor data. The periodic interval time information can be included in the backscatter message, or the data collector device 304 can receive the first few initial messages from each backscatter device 302 to determine the periodic time interval for a given backscatter device 302. The data collector device 304 can then notify the excitation device 306 about the periodic time interval of the excitation signal 206 required by the backscatter device 302 (e.g., by Figure 5 ). The stimulus device 306 may also send the stimulus signal 206 as a combination of different frequencies, power levels, antennas (in the case where the transmitter has multiple antennas), and based on the received signal quality of the backscatter data. For example, the data collector device 304 may create a whitelist of these parameters for each transmitter.

[0066] For the random transmission method, each backscatter device 302 can collect data in a random time period so that once the timer expires, the backscatter device 302 can backscatter data and the time interval for the next round of transmission. The data collector device 304 can notify the excitation device 306 about the next time interval for sending the excitation signal 206 for the backscatter device 302. Similar to the periodic example, the excitation signal 206 can be sent through different combinations of frequencies, power levels, and antennas (in the case of a transmitter with multiple antennas) to allow the data collector device 304 to create a whitelist combination over time. In an alternative, the backscatter device 302 can also wake up randomly and decide whether to transmit based on a random probability (e.g., taken from a uniform distribution between 0 and 1). If the probability is above a predefined threshold (e.g., 1 / n, where n is the total number of backscatter devices 302), the backscatter device 302 can backscatter, otherwise the backscatter device 302 cannot backscatter. In response to the backscatter device 302 determining not to backscatter, the backscatter device 302 can wait for a shorter random time again before calculating the probability of transmission. This method is similar to p-persistent Carrier Sense Multiple Access (CSMA).

[0067] For the low power wake-up receiver approach, each backscatter device 302 may be equipped with a wake-up circuit 315. The wake-up circuit 315 may trigger the backscatter device 302 to perform backscattering in response to the excitation signal 206 exceeding a predefined threshold signal level. This may solve the problem of only performing transmission when the transmitter is within a certain distance. With transmit power control, it may be ensured that only the backscatter device 302 with a transmitter on the body will wake up and perform backscattering. This approach may be acceptable if there is only a single backscatter device 302 on the body.

[0068] However, in the case of many backscatter devices 302, an additional method for channel arbitration may be needed to ensure that messages can be received from all backscatter devices 302. Otherwise, if these messages are ignored or overlapped or otherwise cannot be received, the energy in the transmission may be wasted. Such channel arbitration can be performed in a variety of ways, such as those indicated below. One or more of these channel arbitration methods can be combined to further improve the performance of multiple backscatter devices 302.

[0069] In one channel arbitration method, each backscatter device 302 may randomly decide to backscatter or not to backscatter (e.g., when the backscatter device 302 has data to provide). When the backscatter device 302 has no data to send, it may not need to backscatter unless the time between the last backscatter communications exceeds a predetermined transmission timeout. In this case, the backscatter device 302 may still backscatter a message to indicate that the backscatter device 302 is still valid.

[0070] In another channel arbitration method, each backscatter device 302 can backscatter on a different channel, so at the receiver, we have multiple receivers (e.g., operating on different channels) or a software radio that can receive all backscatter messages simultaneously. Or the receiver can decide which backscatter device 302 to tune to. In this case, energy may be spent on backscatter devices 302 that are not necessary to listen to.

[0071] In another channel arbitration method, a node identifier (ID) may be encoded in a wake-up signal that is detected by a pattern correlator at the receiver. This may allow the indicated backscatter node to respond while other backscatter devices 302 ignore the wake-up message.

[0072] Figure 6An example of an optimized periodic wakeup using a channel arbitration technique is shown. For example, a time offset can be piggybacked in the wakeup pattern along with the node ID to inform the backscatter device 302 of its time period for transmission. During normal transmission, the BAN 300 does not need to include a wakeup pattern, thereby reducing energy consumption and enhancing system capacity. To offset normal clock drift, such a configuration message can be sent from time to time. The configuration message can be sent from the device sending the excitation signal 206 or from the receiver itself.

[0073] As also shown, the data collector device 304 can send a periodic offset to the stimulus device 306. The stimulus device 306 can then send a configuration event to the backscatter device 302, which can include a wakeup signal with a wakeup pattern and / or a periodic offset. In the alternative, the stimulus device 306 can send a configuration event to the backscatter device 302, which can include a wakeup signal with a wakeup pattern and / or a periodic offset. In response to the periodic wakeup for data transmission occurring, the backscatter device 302 can send message data via backscatter.

[0074] Figures 7A-7H Aspects of the system protocol design and message formats (including message scheduling) are shown. Two approaches are discussed: a non-pipelined single radio architecture and a pipeline-enabled dual radio architecture.

[0075] In the pipeline-less single radio architecture, it is assumed that the data collector device 304 has only one radio, and therefore all devices are scheduled sequentially. Initially, a configuration phase is performed in which the controller device sends a Beacon C (configuration) message to configure at least the backscatter device 302. This instructs the stimulus device 306 to broadcast a wake-up pattern, followed by a configuration Beacon C message. During the configuration phase, each universal sensor device 307 and backscatter device 302 is scheduled so that each of them can transmit in its respective assigned / calculated time slot during the data collection phase.

[0076] In a pipeline-enabled dual radio architecture, it is assumed that there are two radios at the data collector device 304 for reception: one for the universal sensor device 307 and one for the backscatter device 302. The advantage of this architecture is that the backscatter device 302 can be configured in parallel on a separate channel (i.e., pipelined) while the universal sensor device 307 is being configured. Another advantage is that the duration of the data collection phase is shorter. Here, there is no need to send a separate excitation signal 206, because the data transmitted by the universal sensor device 307 can be used as an excitation signal 206 by the backscatter device 302 to backscatter their different signals using the codeword translation explained here. Therefore, at the cost of adding a radio at the receiver, the system capacity can be doubled. An alternative arrangement can collect data from all universal sensor devices 307 using the collector and collect data from all backscatter devices 302 using the HMI / display device (or vice versa). The device receiving the data can therefore have both the original data from the sensor and the encoded data from the backscatter signal 208, which can be used to decrypt the backscatter message.

[0077] Key messages for these architectures may include Beacon C messages, Configuration messages, Beacon D (Data) messages, and Data Collection messages.

[0078] Fig. 7A An example of configuring a beacon message (Beacon C) is shown. As shown, the Beacon C message may include a physical header, a media access control (MAC) header, and / or other optional headers or optional data for the physical layer and / or protocol used. Depending on the protocol used, the Beacon C message may also include a data correction check, such as a cyclic redundancy check (CRC) or a frame check sequence (FCS). In addition, the Beacon C message may also be encrypted using a method agreed upon during the pairing process of the corresponding wireless technology.

[0079] The payload of the Beacon C message may include information used by the stimulus device 306 when initiating system configuration. For example, to identify the message as a Beacon C message, the Beacon C message may include a configuration bit set to "1" (or another value indicating that the Beacon C message is a configuration message). In addition, the Beacon C message may include a timestamp for synchronizing the system clocks of network devices and avoiding replay attacks. The Beacon C message may also include the total number of devices (e.g., the general sensor device 307 and the backscatter device 302) and optionally include an offset value for indicating the start of the data collection phase.

[0080] In response to receiving the Beacon C message, the stimulus device 306 or other device responsible for generating the stimulus signal 206 (if any) can proceed to configure each backscatter device 302. The stimulus device 306 or other responding device can also send a system broadcast wake-up pattern, which includes a pattern indicating the start of a configuration cycle. This can be used by other devices to synchronize their clocks.

[0081] Figure 7B An example of a configuration sensor (CS) message for a generic sensor device 307 is shown. These CS messages may be sent individually to generic sensor devices 307 to inform the generic sensor devices 307 of the channel and time offset (relative to the reception of the data collection cycle beacon message) for data transmission. When the number of devices is small, there may also be one large beacon message with data for all sensors 102. The configuration message may also include its own timestamp or sequence number, for example, to avoid replay attacks.

[0082] Figure 7C An example of a configuration backscatter (CB) message for backscatter devices 302 is shown. For backscatter devices 302, the wake-up signal may include an individual wake-up pattern for each backscatter device 302. The wake-up pattern may be supplemented with additional information, such as a time offset pattern indicating a data collection configuration with an indicated broadcast pattern starting from the receipt of the message or the receipt of the wake-up message. In the first case, the message may also include a periodic wake-up offset pattern. In addition, the wake-up pattern may also be supplemented with a frequency offset and / or a wake-up sequence number pattern (e.g., to avoid replay attacks on the wake-up pattern).

[0083] Configuration of the universal sensor device 307 and the backscatter device 302 may also occur in parallel when the configuration of the universal sensor device 307 and the backscatter device 302 is performed by two different devices (eg, for a pipeline architecture, by the data collector device 304 and the stimulus device 306, respectively).

[0084] Fig.7D An example of a data cycle beacon message (Beacon D) is shown. A Beacon D message can be sent from a controller to initiate data collection, with a configuration bit set to "0" or another value indicating that the Beacon D message is a non-configuration message. The remaining format and content of the Beacon D message can be similar to that in a configuration message. The stimulus device 306 can also send a system broadcast wake-up pattern that includes a pattern indicating the start of a data transfer cycle. This can be used by the device to synchronize its clock.

[0085] Fig. 7EExamples of sensor data messages (DS) are shown. These sensor data messages may be sent from the generic sensor devices 307. During the data collection phase, each generic sensor device 307 transmits its data to the data collector device 304 according to its assigned offset.

[0086] Figure 7F An example of a backscatter data message (DB) is shown. For a backscatter device 302, when the excitation device 306 continuously sends the excitation signal 206 during the data collection phase, the backscatter device 302 also periodically wakes up to transmit the backscatter signal 208. The excitation device 306 can also send the excitation signal 206 based on a whitelist combination of channels, power levels, antennas, etc. set by the receiver / collector / wake-up device during the configuration phase. The backscatter data message itself can conform to the standard protocol and therefore can have its associated header and data check bits. These devices can also include their time offset values, which can help the receiver / collector to start synchronization as needed.

[0087] Depending on the application data rate requirements, there may be gaps between consecutive data collection cycles, which are indicated by offsets in the data period beacon.

[0088] Figure 7G An example of a periodic message schedule for data transmission in a pipeline-free single radio receiver architecture is shown. As shown in the figure, during the configuration phase, a beacon C message is sent, for example, by a collector / receiver device (e.g. Fig. 7A ), followed by a CS message (as shown Figure 7B Another source (stimulus source) sends a CB message (as shown in Figure 7C In doing so, the CS and CB messages may be sent simultaneously and / or in an overlapping pattern on different channels, thereby speeding up the configuration phase. This pattern may be repeated (e.g., periodically). It should also be noted that the order of the Beacon C, CS, and CB messages is not relevant and may be sent in an order different from that shown. During the data phase, a Beacon D message may be sent (e.g., Fig.7D ), followed by a DS message (as shown Fig. 7E ), followed by a DB message (such as Figure 7F This pattern may also be repeated (eg, periodically). It should also be noted that the relative order of the Beacon D, DS, and DB messages may be different than that shown.

[0089] Figure 7HAn example of a periodic message schedule for data transfer in a pipelining-enabled two separate receiver / single receiver device architecture with two radios is shown. Here again, the first source (collector / receiver) sends a beacon and a CS message, while the other source (collector / receiver) sends a CB message. Furthermore, since two receivers or two radios are used, the first source sends a beacon D and receives a DS message, while the second source simultaneously receives a DB message.

[0090] Figures 8A-8G 9 show an optimized pipeline architecture with data aggregation that may also be provided by BAN 300. In this variation, the general sensor devices 307 may be scheduled for backscatter communications. In each data communication time slot, one of the backscatter devices 302 may be awakened for backscattering. The data is received by the next scheduled general sensor device 307 (or a dedicated general sensor device 307). The general sensor device 307 then transmits its own data and the aggregated data from the backscatter device 302 in its own time slot. In this approach, BAN 300 may only require the data collector device 304.

[0091] The nth backscatter device 302N may transmit to the general sensor device 307(n-1). Then, in the next cycle, the general sensor device 307(n-1) may transmit its own data along with the data of the nth backscatter device 302. The wake-up pattern may be generated by the general sensor device 307, which will listen to the corresponding backscatter device 302, and the signal transmitted by the general sensor device 307 in the time slot is used to stimulate the backscatter device 302. The backscatter device 302 then uses the codeword translation backscatter to transmit the backscatter signal 208. Assuming that the general sensor device 307 has its own transmitted raw sensor data, the general sensor device 307 may decrypt the message included in the backscatter signal 208 (e.g., such as Figure 4 404).

[0092] Alternatively, a separate device may be used to generate the wake-up pattern and the continuous excitation signal 206 for the backscatter device 302. For example, such a separate device may be used only in the first data transmission cycle, because after that, the backscatter device 302 may periodically wake itself up. In addition, the data collector device 304 may also transmit a broadcast wake-up pattern at the beginning of each data cycle to synchronize the backscatter device 302.

[0093] Fig. 8A An example of a configuration beacon C message for an architecture including data aggregation is shown. As shown, the beacon C message is similar to the beacon C message without data aggregation.

[0094] Figure 8B An example of a CS message of an architecture including data aggregation is shown. The CS message includes a channel / offset and a time offset for transmission and reception compared to a CS message without aggregation.

[0095] Figure 8C An example of a CB for a backscatter device 302 of an architecture including data aggregation is shown. As shown, the CB message is similar to a CB message without data aggregation.

[0096] Fig.8D An example of a beacon D of an architecture including data aggregation is shown. As shown, beacon D is again similar to beacon D without data aggregation.

[0097] Fig. 8E An example of a DS including an architecture of data aggregation is shown. As shown, the DS message additionally includes sensor data received from the backscatter device 302 in addition to the sensor data of the general sensor device 307 itself.

[0098] Figure 8F An example of a backscatter data message (DB) for an architecture including data aggregation is shown. The message is similar to a DS message for an architecture without data aggregation.

[0099] Figure 8G An example of periodic message scheduling for data transmission in a pipeline-enabled single-receiver architecture with data aggregation is shown. As shown for the configuration phase, the first source sends a beacon C message (such as Fig. 8A ) and CS messages (such as Figure 8B Once the configuration phase is complete, during the data collection phase, the first source sends a beacon D message (as shown in Fig.8D Each sensor then sends a DS message (e.g., including data from a previous DB message from the corresponding backscatter device 302) during its pre-assigned time slot. Fig. 8E ), while the second source simultaneously sends a DB message (as Figure 8F The first group of DB messages can also be combined with CB messages (such as Figure 8C ), to allow the wake-up mode of the backscatter device 302 to be set.

[0100] Fig. 9An example data flow diagram 900 of periodic message scheduling for data delivery in a pipeline-enabled single receiver architecture with data aggregation is shown. First, during the configuration phase, the data collector device 304 sends a beacon C message that is received by each universal sensor device 307. Next, the data collector device 304 sends CS1-CS n Messages are sent to the corresponding universal sensor devices 307 (1 to n). Once this phase is complete, in the data collection phase, the data collector device 304 sends a beacon D message to the sensor universal sensor device 307. The universal sensor device 307 then sends a CB message to the backscatter device 302 to configure the backscatter device 302. The backscatter device 302 then responsively sends a DB message to the universal sensor device 307 (e.g., according to the configured time offset and the excitation signal 206 (e.g., which can be the transmission of a previous data set from the universal sensor device 307)). The content of these DB messages can then be compiled into DS messages sent from the universal sensor device 307 to the data collector device 304. .

[0101] It should be noted that the pipeline architecture may be particularly useful when the number of backscatter devices 302 is equal to or less than the number of general sensor devices 307 in the BAN 300 .

[0102] It should also be noted that in order to achieve power optimization, the sensor device can be equipped with backscatter capabilities. In this case, the device can switch between the general sensor device 307 mode and the backscatter device 302 mode in turn. In the example, the general sensor device 307 that transmits more frequently can switch itself to the backscatter device 302 mode and can use all backscatter time slots for data communication in a pipeline architecture to achieve power optimization.

[0103] It should also be noted that in all of the above architectures, when each backscatter device 302 is explicitly awakened to receive the wake-up signal pattern, an additional guard band can be used before each backscatter device 302. In some examples, the backscatter devices 302, data collector devices 304, stimulus devices 306, and general sensor devices 307 can also enable data encoding, in which case they send processed data or only differential data in their time slots to optimize their own respective overall transmissions.

[0104] Therefore, sensors 102 with backscatter capabilities can be used in BAN 300 to provide an order of magnitude power savings for wireless communications. To support various quality of service requirements, management of backscatter devices 302 can be implemented using various architectures, including: a non-pipelined single radio receiver architecture; a non-pipelined single radio receiver architecture with a dedicated wake-up source; a pipeline-enabled dual receiver / receiver architecture with two radios; and a pipeline-enabled single receiver architecture with data aggregation.

[0105] Fig.10 An example 1000 of a computing device 1002 for use in a BAN 300 architecture is shown. Fig.10 , and refer to Figure 1-9 , sensor 102, backscatter device 302, data collector device 304, general sensor device 307, wake-up device 402, etc. may be examples of such computing device 1002. As shown, computing device 1002 includes processor 1004, which is operably connected to storage device 1006, network device 1008, output device 1010, and input device 1012. It should be noted that this is just one example, and computing devices 1002 with more, fewer, or different components may be used.

[0106] The processor 1004 may include one or more integrated circuits that implement the functions of a central processing unit (CPU) and / or a graphics processing unit (GPU). In some examples, the processor 1004 is a system on a chip (SoC) that integrates the functions of the CPU and GPU. The SoC may optionally include other components (such as, for example, a storage device 1006 and a network device 1008) into a single integrated device. In other examples, the CPU and the GPU are interconnected via a peripheral connection device (such as a high-speed peripheral component interconnect (PCI) or another suitable peripheral data connection). In one example, the CPU is a commercially available central processing device that implements an instruction set such as one of the following: a microprocessor of the x86, ARM, Power, or MIPS instruction set family.

[0107] Regardless of the specific case, during operation, the processor 1004 executes stored program instructions retrieved from the storage device 1006. Thus, the stored program instructions include software that controls the operation of the processor 1004 to perform the operations described herein. The storage device 1006 may include both non-volatile memory and volatile memory devices. Non-volatile memory includes solid-state memory, such as NAND flash memory, magnetic and optical storage media, or any other suitable data storage device that retains data when the system is disabled or powered off. Volatile memory includes static and dynamic random access memory (RAM) that stores program instructions and data during operation of the system 100.

[0108] The GPU may include hardware and software for displaying at least two-dimensional (2D) graphics and optionally 3D graphics to output device 1010. Output device 1010 may include a graphics or visual display device, such as an electronic display screen, a projector, a printer, or any other suitable device for reproducing a graphical display. As another example, output device 1010 may include an audio device, such as a speaker or headphones. As yet another example, output device 1010 may include a tactile device, such as a mechanically elevable device, which in an example may be configured to display Braille or other physical output that may be touched to provide information to a user.

[0109] Input device 1012 may include any of a variety of devices that enable computing device 1002 to receive control input from a user. Examples of suitable input devices that receive human interface input may include a keyboard, mouse, trackball, touch screen, voice input device, graphics tablet, etc.

[0110] The network devices 1008 may each include any of a variety of devices that enable various devices to send and / or receive data from external devices over a network. Examples of suitable network devices 1008 include Ethernet interfaces, Wi-Fi transceivers, cellular transceivers, Bluetooth or BLE transceivers, ultra-wideband (UWB) transceivers, or other network adapters or peripheral interconnect devices that receive data from another computer or external data storage device, which can be used to receive large data sets in an efficient manner.

[0111] The process, method or algorithm disclosed herein may be delivered to / implemented by a processing device, a controller or a computer, which may include any existing programmable electronic control unit or a dedicated electronic control unit. Similarly, the process, method or algorithm may be stored in a variety of forms as data and instructions executable by a controller or a computer, including but not limited to information permanently stored on a non-writable storage medium (such as a read-only memory (ROM) device) and information variably stored on a writable storage medium (such as a floppy disk, a tape, a compact disk (CD), a RAM device and other magnetic and optical media). The process, method or algorithm may also be implemented in a software executable object. Alternatively, the process, method or algorithm may be embodied in whole or in part using a suitable hardware component (such as an ASIC, a field programmable gate array (FPGA), a state machine, a controller or other hardware component or device, or a combination of hardware, software and firmware components).

[0112] Although exemplary embodiments are described above, these embodiments are not intended to describe all possible forms covered by the claims. The words used in the specification are descriptive rather than restrictive, and it should be understood that various changes can be made without departing from the spirit and scope of the present disclosure. As mentioned above, the features of the various embodiments can be combined to form further embodiments of the present invention that may not be explicitly described or illustrated. Although various embodiments may be described as providing advantages or being preferred relative to other embodiments or prior art implementations in terms of one or more desired characteristics, it is recognized by those of ordinary skill in the art that one or more features or characteristics may be sacrificed to achieve the desired overall system properties, depending on the specific application and implementation. These properties may include, but are not limited to, strength, durability, life cycle, marketability, appearance, packaging, size, applicability, weight, manufacturability, ease of assembly, etc. Therefore, even if any embodiment is described as not as desirable as other embodiments or prior art implementations in terms of one or more characteristics, these embodiments do not exceed the scope of the present disclosure and may be desirable for specific applications.

Claims

1. A method for configuring and utilizing a body area network (BAN), comprising: In a configuration phase, sending a configuration message for scheduling the plurality of backscatter devices such that during a data collection phase, each of the plurality of backscatter devices is configured to backscatter from the excitation signal in a separately allocated time slot; as well as During the data collection phase, sensor data messages including sensor data from the backscatter devices are received from the plurality of backscatter devices to the data collector device, the sensor data messages being scheduled according to the configuration phase.

2. The method according to claim 1, further comprising: During the data collection phase, a data period beacon message for scheduling multiple backscatter devices is sent to indicate the start of a data transmission period.

3. The method according to claim 1, further comprising: In the configuration phase, configuration messages for scheduling the plurality of general purpose sensor devices having transmit and receive functions are sent, such that during the data collection phase, each of the plurality of general purpose sensor devices is also configured to transmit in a separately allocated time slot.

4. The method according to claim 3, further comprising during the data collection phase: receiving a backscatter sensor data message from a corresponding one of the plurality of backscatter devices to each universal sensor device, the backscatter sensor data message including sensor data received from the backscatter device; as well as A generic device sensor data message is sent from the generic sensor device to the data collector device, the generic device sensor data message including sensor data captured by the generic sensor device and also sensor data received from the backscatter device.

5. The method of claim 4, wherein a configuration message for scheduling a plurality of general sensor devices is sent in a different channel than a configuration message for scheduling a plurality of backscatter devices. The method of claim 4 , wherein the backscatter sensor data message is modulated as an excitation signal on the generic device sensor data message.

7. The method of claim 1, wherein the configuration message includes a timestamp to synchronize system clocks of the plurality of backscatter devices.

8. The method of claim 1, wherein the configuration message includes a total number of the plurality of backscatter devices and / or an offset value to indicate the start of a data collection phase.

9. The method of claim 1, wherein the configuration message is sent from a data collector device.

10. The method of claim 1, wherein the configuration message is sent from an activation device.

11. A system for configuring and utilizing a body area network (BAN), comprising: multiple backscatter devices; as well as A data collector device, wherein: In a configuration phase, the plurality of backscatter devices are configured to receive a configuration message for scheduling transmissions of the plurality of backscatter devices such that during a data collection phase, each of the plurality of backscatter devices is configured to transmit in an individually assigned time slot, and During the data collection phase, the data collector device is configured to receive sensor data messages including sensor data from the backscatter devices from the plurality of backscatter devices, the sensor data messages being scheduled according to the configuration phase.

12. The system of claim 11, wherein during the data collection phase, the plurality of backscatter devices are configured to transmit sensor data messages in response to receipt of a data period beacon message, the data period beacon message indicating the start of a data transmission period.

13. The system of claim 11, further comprising: Multiple general purpose sensor devices with transmit and receive capabilities, In the configuration phase, the plurality of general sensor devices are configured to receive a configuration message to schedule the plurality of general sensor devices to transmit in individually allocated time slots in the data collection phase.

14. The system of claim 13, wherein during the data collection phase: Each generic sensor device is configured as: receiving a backscatter sensor data message from a corresponding one of the plurality of backscatter devices, the backscatter sensor data message comprising sensor data received from the corresponding one of the plurality of backscatter devices; and A generic device sensor data message is sent to the data collector device, the generic device sensor data message including sensor data captured by the generic sensor device and also sensor data received from the backscatter device.

15. The system of claim 14, wherein a configuration message for scheduling the plurality of general sensor devices is sent in a different channel than a configuration message for scheduling the plurality of backscatter devices.

16. The system of claim 14, wherein the backscatter sensor data message is modulated on the generic device sensor data message as an excitation signal.

17. The system of claim 11, wherein the configuration message includes a timestamp to synchronize system clocks of the plurality of backscatter devices.

18. The system of claim 11, wherein the configuration message includes a total number of the plurality of backscatter devices and / or an offset value to indicate the start of a data collection phase.

19. The system of claim 11, wherein the configuration message is sent from a data collector device.

20. The system of claim 11, wherein the configuration message is sent from the stimulus device.

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