Intelligence, security, and vehicular sensor networks in internet of things (IoT)-enabled smart-cities: An overview

Long-range sub-GHz technologies such as LoRaWAN, SigFox, IEEE 802.15.4, and DASH7 are increasingly popular for academic research and daily life applications. However, especially in the European Union (EU), the use of their corresponding frequency bands are tightly regulated, since they must confirm to the short-range device (SRD) regulations. Regulations and standards for SRDs exist on various levels, from global to national, but are often a source of confusion. Not only are multiple institutes responsible for drafting legislation and regulations, depending on the type of document can these rules be informational or mandatory. Regulations also vary from region to region; for example, regulations in the United States of America (USA) rely on electrical field strength and harmonic strength, while EU regulations are based on duty cycle and maximum transmission power. A common misconception is the presence of a common 1% duty cycle, while in fact the duty cycle is frequency band-specific and can be loosened under certain circumstances. This paper clarifies the various regulations for the European region, the parties involved in drafting and enforcing regulation, and the impact on recent technologies such as SigFox, LoRaWAN, and DASH7. Furthermore, an overview is given of potential mitigation approaches to cope with the duty cycle constraints, as well as future research directions.

https://link.springer.com/content/pdf/10.1186/s13638-019-1502-5.pdf

Impact of EU duty cycle and transmission power limitations for sub-GHz LPWAN SRDs: an overview and future challenges

According to many studies, motor vehicle collisions lead to many deaths and disabilities, and bring about huge economic losses to societies and individuals around the world. If risky scenarios could be recognized and the driver could be timely warned, the frequency of traffic accidents could be reduced effectively, and traffic safety could be improved. This article summarizes the current state of the research on safety warnings under connected vehicle environments-from risk recognition algorithms, collision avoidance systems, dangerous event identification and notification methods, real-time safety warning system and effects of various types of warning information notifications. At the end of this article, the conclusions of this work are presented, and possible future directions for safety warning research under connected vehicle environments are discussed. This article represents the current research status of safety warnings under connected vehicle environments to some extent, which can provide references for future safety warning research in terms of framework, methods and technologies, etc.

A Survey of Safety Warnings Under Connected Vehicle Environments

Street-centric routing scheme using ant colony optimization-based clustering for bus-based vehicular ad-hoc network

Driver’s intention of the front vehicle plays an important role in the automatic emergency braking (AEB) system. If the front vehicle brakes suddenly, there is potential collision risk for following vehicle. Therefore, we propose a driver’s intention recognition model for the front vehicle, which is based on the backpropagation (BP) neural network and hidden Markov model (HMM). The brake pedal, accelerator pedal, and vehicle speed data are used as the input of the proposed BP-HMM model to recognize the driver’s intention, which includes uniform driving, normal braking, and emergency braking. According to the recognized driver’s intention transmitted by Internet of vehicles, an AEB model for the following vehicle is proposed, which can dynamically change the critical braking distance under different driving conditions to avoid rear-end collision. In order to verify the performance of the proposed models, we conducted driver’s intention recognition and AEB simulation tests in the cosimulation environment of Simulink and PreScan. The simulation test results show that the average recognition accuracy of the proposed BP-HMM model was 98%, which was better than that of the BP and HMM models. In the Car to Car Rear moving (CCRm) and Car to Car Rear braking (CCRb) tests, the minimum relative distance between the following vehicle and the front vehicle was within the range of 1.5 m–2.7 m and 2.63 m–5.28 m, respectively. The proposed AEB model has better collision avoidance performance than the traditional AEB model and can adapt to individual drivers.

/pdf/an-automatic-emergency-braking-model-considering-driver-s-k5rsgzawcb.pdf

An automatic emergency braking model considering driver's intention recognition of the front vehicle

In this paper we present the design and development of an industrial grade wireless base station for industrial monitoring and control using wireless sensor networks. This paper highlights the need for a base station for wireless sensor networks, the challenges in deploying in industrial environments, the requirements of the base station in addressing those challenges and the design of an industrial grade wireless base station. Although a wireless sensor node is efficient enough to act as a base station in a wireless sensor network their processing power and communication capabilities are limited since they are designed to work at very low power. A large scale wireless sensor network usually consists of thousands of motes which have low-memory, low processing power, and limited communication capacity. To collaboratively monitor environment and obtain global information, centralized data processing by Base Station is necessary. A Base Station is a powerful device which has much higher processing power, more memory and much higher communication capabilities. The Industrial Wireless Base Station (iWase) built around the powerful AT91SAM9XE512 controller has higher processing power and supports Ethernet (wired) and GSM/GPRS (wireless) communication in addition to IEEE 802.15.4 radio communication with sensor nodes. iWase is provided with an ingress protection of IP65, which facilitates operation in harsh outdoor environments. iWase also provides excellent operation in the industrial environment with an operating temperature range of −40 to +85°C.

Industrial grade wireless base station for Wireless sensor networks

Dedicated Short Range Communications (DSRC), a wireless standard, is considered to be the most promising protocol to be used for Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communications. The DSRC standard is specifically designed for automotive use, focused on vehicular safety applications. Most of the road accidents are accounted due to non-focused drivers and unpredicted roads, which could be reduced to a great extend using DSRC enabled alert systems. This paper describes the design and implementation of DSRC based On-Board and Road Side Units as well as the architecture and functional aspects of the DSRC protocol along with two vehicular safety applications developed and tested.

Safety Alert Systems Using Dedicated Short Range Communication for on Road Vehicles

The increasing number of collisions at intersections calls for a reliable and safe, real time collision warning system that can alert the drivers about a potential collision. Although many kinds of collision warning systems are available, the problems related to acceleration change and curved road scenarios are to be considered to improve the accuracy of the system. In the proposed paper, an efficient intersection collision avoidance system for straight and curved roads are considered. The objective of the project is to predict the location of the vehicle 10 seconds in future. The location, speed and heading information of a vehicle are available through a GPS device. Accelerometer provides the acceleration/deceleration information of the vehicles. Kalman filter with GPS and accelerometer as inputs can be used to predict the future location of the vehicle. These predicted locations are checked to be on the road or not using GIS map. If off road, the locations are projected onto the road with the help of the coordinate data. A warning message in the form of alarms or lights are generated when the distance between the predicted locations of the host vehicle and target vehicle falls below a threshold value. Position information are exchanged between the vehicles using Dedicated Short Range Communication. The MATLAB simulation results validate our proposed system by reducing the prediction error with the combination of GIS and kalman filter. False alarms are reduced considerably in the proposed system for collision avoidance.

DSRC based collision warning for vehicles at intersections

This document specifies a new type for the 6LoWPAN routing header
containing the delivery deadline time for data packets. The deadline
time enables forwarding and scheduling decisions for time critical IoT
M2M applications that need deterministic delay guarantees over
constrained networks and operate within time-synchronized networks.

Packet Delivery Deadline time in 6LoWPAN Routing Header

The Internet Engineering Task Force (IETF) has set up the 6TiSCH Working Group (WG) to focus on enabling IPv6 over the Time Slotted Channel Hoping (TSCH) mode of the IEEE 802.15.4-2015 standard. This paper describes our Contiki implementation of the 6TiSCH operation sublayer, 6top, which is used for dynamic scheduling of bandwidth between the neighboring sensor nodes and facilitate the On the Fly (OTF) scheduling.

Lijo Thomas

Papers

Industrial grade wireless base station for Wireless sensor networks

Safety Alert Systems Using Dedicated Short Range Communication for on Road Vehicles

DSRC based collision warning for vehicles at intersections

Packet Delivery Deadline time in 6LoWPAN Routing Header

6TiSCH operation sublayer (6top) implementation on Contiki OS