The Internet of Things (IoT) is rapidly becoming an integral part of our life and also multiple industries. We expect to see the number of IoT connected devices explosively grows and will reach hundreds of billions during the next few years. To support such a massive connectivity, various wireless technologies are investigated. In this survey, we provide a broad view of the existing wireless IoT connectivity technologies and discuss several new emerging technologies and solutions that can be effectively used to enable massive connectivity for IoT. In particular, we categorize the existing wireless IoT connectivity technologies based on coverage range and review diverse types of connectivity technologies with different specifications. We also point out key technical challenges of the existing connectivity technologies for enabling massive IoT connectivity. To address the challenges, we further review and discuss some examples of promising technologies such as compressive sensing (CS) random access, non-orthogonal multiple access (NOMA), and massive multiple input multiple output (mMIMO) based random access that could be employed in future standards for supporting IoT connectivity. Finally, a classification of IoT applications is considered in terms of various service requirements. For each group of classified applications, we outline its suitable IoT connectivity options.

IoT Connectivity Technologies and Applications: A Survey

Backscatter communication promises significant power and complexity advantages for Internet of Things devices such as radio frequency identification (RFID) tags and wireless sensor nodes. One perceived disadvantage of backscatter communication has been the requirement for specialized hardware such as RFID readers to receive backscatter signals. In this paper, we show how backscatter signals can be designed for compatibility with the Bluetooth 4.0 low energy (BLE) chipsets already present in billions of smart phones and tablets. We present a prototype microcontroller-based “BLE-Backscatter” tag that produces bandpass frequency-shift keying modulation at 1 Mb/s, enabling compatibility with conventional BLE advertising channels. Using a +23-dBm equivalent isotropically radiated power continuous wave (CW) carrier source, we demonstrate a range of up to 13 m between the tag and an unmodified Apple iPad Mini as well as a PC with the Nordic Semiconductor nRF51822 chipset. With the tag 1 m from the receiver, we demonstrate a range of up to 30 m between the CW carrier source and the tag. In both cases, the existing Bluetooth stack was used, with no modifications whatsoever to hardware, firmware, or software. The backscatter tag consumes only 1.56 nJ/b, over $6\times $ less than the lowest power commercial Bluetooth transmitters.

BLE-Backscatter: Ultralow-Power IoT Nodes Compatible With Bluetooth 4.0 Low Energy (BLE) Smartphones and Tablets

https://hal.archives-ouvertes.fr/hal-01960231/document

A sensor-centric survey on the development of smartphone measurement and sensing systems

In this paper, we successfully developed a Bluetooth Low Energy (BLE) based blood pressure monitoring system, which integrated a homemade blood pressure measuring device and a smartphone. The device uses single BLE System-on-Chip to process the algorithm of blood pressure measurement and data transmission. Through the newest Bluetooth Low Energy technology, device can send measured results to the smartphone. Therefore, users can get the information of systolic blood pressure, diastolic blood pressure and pulse rate on the smartphone. Besides, the format of data transmission packet is based on the standard Blood Pressure Profile specification from Bluetooth SIG. The homemade blood pressure monitor has high compatibility to communication with other devices using the same Bluetooth profile. The accuracy of pulse rate and blood pressures are verified through the CuffLink simulator. The accuracy of pulse rate is −1.13 ± 0.52 beats, the accuracy of systolic blood pressure is 0.69 ± 1.63 mmHg, and the accuracy of diastolic blood pressure is 0.20 ± 1.02 mmHg. In clinical trials, the systolic blood pressure average difference between our method and auscultatory method is 2.66 ± 2.71 mmHg. The diastolic blood pressure average difference between our method and auscultatory method is 3.42 ± 4.42 mmHg. As a result, this device has high accuracy for measuring blood pressure and pulse rate.

Bluetooth Low Energy (BLE) based blood pressure monitoring system

Bluetooth Low Energy (BLE) is quickly and steadily gaining importance for a wide range of applications. In this paper we investigate the potential of BLE in a vehicular context. By means of experiments, we first evaluate the characteristics of the wireless channel, then we define a set of driving scenarios to analyse how BLE is affected by varying speed, distance and traffic conditions. We found that the maximum communication range between two devices can go beyond 100?m and that a robust connection, capable of handling sudden signal losses or interferences, can be achieved up to a distance of 50?m even for varying traffic and driving conditions. We then present a proof-of-concept mobile application for off-the-shelf smartphones that can be used to transmit data over multiple hops. Next, we analyse how BLE handles other interferences on the same frequency band by building and validating an interference testbed based on the IEEE 802.11 technology. Finally we discuss the advantages and limitations of BLE for Inter-Vehicular Communications (IVC) and propose potential applications.

Bluetooth Low Energy performance and robustness analysis for Inter-Vehicular Communications

Self blood pressure (BP) management, monitoring, and treatment are very important and helpful for the people with hypertension. In this paper, we proposed a new mobile intelligent BP monitor based on a smartphone. This monitor comprises a homemade wrist BP monitor and an Android smartphone. The wrist BP monitor and smartphone are with high mobility. Users can set the alarm timer according their requirement. When the time is up, the friendly speech sounds will remind user to measure BP. The measuring data will be updated to the MySQL database and user can query the BP data from smartphone. The proposed monitor can help user to periodic measuring BP and managing BP and achieve the goal of prevention and health care to improve the quality of life. Accuracy of our wrist BP monitor has been verified by a commercial BP monitor and shown the differences of systolic blood pressure is -1.7 ± 6.7 mmHg and the differences of diastolic blood pressure is 2.8 ± 4.6 mmHg.

A Mobile Intelligent Blood Pressure Monitor Based on the Android Smartphone

Human blood pressure (BP) and its pulse wave has always been a popular topic since it’s bound up with the heart related risks. In this paper, we mainly focus on the pulse wave of the brachial artery which is also widely used in the measurement of BP, hence we constructed a brachial artery-based system by using multi-Windkessel model and managed to generate a reliable pulse wave signal with adjustable authentic human parameters. On this basis, the signal filtering technique was also discussed. We mixed noises with different amplitude and frequency into the original signal intentionally, then several filters’ performances were compared. The designed combined filter represented a stable performance, and had little error in BP values, which ensure the stability and reliability of the designed system.

Zhe-Min Lin

Papers

Bluetooth Low Energy (BLE) based blood pressure monitoring system

A Mobile Intelligent Blood Pressure Monitor Based on the Android Smartphone

A brachial artery-based system for blood pressure pulse wave measurement and its signal filtering technique