In this paper we conduct a feasibility study of delay-critical safety applications over vehicular ad hoc networks based on the emerging dedicated short range communications (DSRC) standard. In particular, we quantify the bit error rate, throughput and latency associated with vehicle collision avoidance applications running on top of mobile ad hoc networks employing the physical and MAC layers of DSRC. Towards this objective, the study goes through two phases. First, we conduct a detailed simulation study of the DSRC physical layer in order to judge the link bit error rate performance under a wide variety of vehicles speeds and multi-path delay spreads. We observe that the physical layer is highly immune to large delay spreads that might arise in the highway environment whereas performance degrades considerably at high speeds in a multi-path environment. Second, we develop a simulation testbed for a DSRC vehicular ad hoc network executing vehicle collision avoidance applications in an attempt to gauge the level of support the DSRC standard provides for this type of applications. Initial results reveal that DSRC achieves promising latency performance, yet, the throughput performance needs further improvement.

Six years after the adoption of the standard 4.0, the Bluetooth Special Interest Group (SIG), a non-profit association that deals with the study and the development of technology standards including those of Bluetooth, has officially released the main features of Bluetooth 5.0. It is one of the significant developments in short-range wireless communication technology. As stated by the SIG, the new standard will forever change the way people approach the Internet of Things (IoT), turning it into something that takes place around them in an almost natural and transparent way. In this article, the future IoT scenarios and use cases that justify the push for Bluetooth 5 are introduced. A set of new technical features that are included in Bluetooth 5 are presented, and their advantages and drawbacks are described.

We propose using a wireless network to facilitate communications between sensors/switches and control units located within a vehicle. In a typical modern vehicle, the most demanding sensor will require a latency of approximately less than 1 msec with throughput of 12 kbps. Further, the network will need to support about 15 sensors with this requirement. The least demanding sensor will require a latency of approximately 50 msec with data throughput rate of 5 bps and will need to support about 20 of these types of devices. Initial part of this paper gives an overview of the issues spanning several layers of the protocol stack. Then, we focus on the Medium access control (MAC) layer and derive necessary design parameters based on given network requirements. We evaluate the IEEE 802.15.4 standard with respect to its suitability for use in a prospective intra-vehicle wireless sensor network.

Abstract-With the increasing number of sensors in modern vehicles, using an Intra-Vehicular Wireless Sensor Network (IVWSN) is a possible solution for the automotive industry to address the potential issues that arise from additional wiring harness. Such a solution could help car manufacturers develop vehicles that have better fuel economy and performance, in addition to supporting new applications. However, which wireless technology for IVWSNs should be used for maximizing the aforementioned benefits is still an open issue. In this paper, we propose to use a new wireless technology known as Bluetooth Low Energy (BLE) and highlight a new architecture for IVWSN. Based on a comprehensive study which encompasses an example application, it is shown that BLE is an excellent option that can be used in IVWSNs for certain applications mainly due to its good performance and low-power, low-complexity, and low-cost attributes.c 2015 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works. I. INTRODUCTIONModern production vehicles are highly computerized, and the major functionalities of a vehicle are controlled by several Electrical Control Units (ECUs) inside the vehicle. ECUs need to gather information about the vehicle from the sensors in order to maintain all the required vehicular operations. Currently, most of the sensors inside vehicles are connected by physical wires, so each sensor sends out its data via the wires toward its destination ECU. However, because the complexity of vehicles is getting higher, and the number of applications and gadgets in vehicles keeps increasing, the large number of wires needed for the connection of sensors poses several significant challenges: the first one is the extra weight of the wires. If the extra weight can be eliminated, the weight of vehicles can be reduced and, thus, they can have better fuel economy and performance. Furthermore, the wired connection limits the possible sensor locations and hence the range of applications. The wires themselves are costly, and the cost for car manufacturers to install wires into vehicles can be high. When a vehicle gets older, some wires may deteriorate and cause severe problems, and to replace wires inside a vehicle would be either impossible or very expensive. In order to address these issues, wireless technology was recently proposed for the communications between sensors and ECUs.

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