To Buffer or Not To Buffer: IEEE 802.11p/bd Performance Under Different Buffering Strategies

in 33 Edition of International Teletraffic Congress (ITC), Avignon, France, August 31st - September 3rd 2021 (2021, September)

A fundamental paradigm of the Internet of Things (IoT) consists of agents that communicate updates to each other to perform joint actions, e.g., cooperative awareness in transportation systems, swarms of ... [more ▼]

A fundamental paradigm of the Internet of Things (IoT) consists of agents that communicate updates to each other to perform joint actions, e.g., cooperative awareness in transportation systems, swarms of Unmanned Aerial Vehicles (UAVs), fleet of robots, automated assembly lines and logistics. A common feature of update messaging is emphasis on reliable throughput and freshness of collected data. We develop an analytical model that yields accurate predictions of all relevant metrics, both in terms of moments and probability distributions, for the case of one-hop broadcast update messages exchanged by using a CSMA-based wireless network. The model is validated against simulations and then applied to compare two update message scheduling approaches: providing a minimal buffer resource or providing no buffer. Surprisingly, we prove that having no buffer improves Age of Information (AoI) performance as well as message delivery rate, in spite of dropped packets. This is essentially due to much smaller congestion and hence collision probability in the wireless channel. From a system point of view this suggests a simple design of message handling, with no need of buffering and overwriting older messages. From a modeling point of view, the result supports the definition of simpler models that need not keep into account buffer state. [less ▲]

Age of Information in IEEE 802.11p

in 17th IFIP/IEEE International Symposium on Integrated Network Management (IM): ITAVT Workshop (2021, May)

Vehicle-to-Everything (V2X) communication is essential for facilitating connected and automated driving, where vehicles and other road traffic participants share data instantaneously and cooperate to ... [more ▼]

Vehicle-to-Everything (V2X) communication is essential for facilitating connected and automated driving, where vehicles and other road traffic participants share data instantaneously and cooperate to solve tricky traffic situations in milliseconds. This paper proposes two stochastic models for the V2X standard IEEE 802.11p to characterize amongst other things the Age of Information (AoI), a recently-proposed metric that measures the freshness of information. The first model is based on renewal process analysis of a tagged station with mean field approximation, while the second one adopts Markov chain approach with network level view. Analytical results show that IEEE 802.11p, given its adaptability to event-triggered and aperiodic messaging, supports advanced cooperative driving scenarios. [less ▲]

Towards 2-Hop Neighbor Management for Heterogeneous Vehicular Networks

Poster (2020, December)

Message dissemination protocols for vehicular networks often build upon information maintained in neighbor tables. Due to high mobility and scarce channel capacity available in such networks, algorithms ... [more ▼]

Message dissemination protocols for vehicular networks often build upon information maintained in neighbor tables. Due to high mobility and scarce channel capacity available in such networks, algorithms for maintaining neighbor tables must carefully select which information is transmitted at which time. Recent approaches rely on probabilistic data structures (e.g., Bloom filter) for transmitting such neighbor information in order to reduce channel load, yet they still suffer from scarce channel capacities. In this paper, we propose to use multiple communication technologies (heterogeneous networking) for maintaining neighbor tables by building upon recent 2-hop neighbor management strategies. Promising results show an increase of up to 19 % of covered neighbors in comparison to a Baseline approach that only uses one communication technology. [less ▲]

DeepNDN: Opportunistic Data Replication and Caching in Support of Vehicular Named Data

in 21st IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM) (2020, September)

Although many target applications in VANETs are information-centric, the performance of Named Data Networking (NDN) in vehicular ad-hoc networks is severely hampered by persistent network partitioning ... [more ▼]

Although many target applications in VANETs are information-centric, the performance of Named Data Networking (NDN) in vehicular ad-hoc networks is severely hampered by persistent network partitioning, typical of many vehicular scenarios. Existing approaches try to address this issue by relying on opportunistic communications. However, they leave open the crucial issue of how to guarantee content persistence and tight QoS levels while optimizing the resource utilization in the vehicular environment. In this work we propose DeepNDN, a communication scheme based on the joint application of NDN and of probabilistic spatial content caching, which enables content retrieval in fragmented and dynamic network topologies with tight delay constraints. We present a data-based approach to DeepNDN management, based on locally modulating content replication and delivery in order to achieve a target hit ratio in a resource-efficient manner. Our management algorithm employs a Convolutional Neural Network (CNN) architecture for effectively capturing the complex relations between spatio-temporal patterns of mobility and content requests and DeepNDN performance. Its numerical assessment in realistic, measurement-based scenarios suggest that our management approach achieves its target set goals while outperforming a set of reference schemes. [less ▲]

A Data-Driven Minimal Approach for CAN Bus Reverse Engineering

in 3rd IEEE Connected and Automated Vehicles Symposium, Victoria, Canada, 4-5 October 2020 (2020)

Current in-vehicle communication systems lack security features, such as encryption and secure authentication. The approach most commonly used by car manufacturers is to achieve security through obscurity ... [more ▼]

Current in-vehicle communication systems lack security features, such as encryption and secure authentication. The approach most commonly used by car manufacturers is to achieve security through obscurity – keep the proprietary format used to encode the information secret. However, it is still possible to decode this information via reverse engineering. Existing reverse engineering methods typically require physical access to the vehicle and are time consuming. In this paper, we present a Machine Learning-based method that performs automated Controller Area Network (CAN) bus reverse engineering while requiring minimal time, hardware equipment, and potentially no physical access to the vehicle. Our results demonstrate high accuracy in identifying critical vehicle functions just from analysing raw traces of CAN data. [less ▲]

Fog Seeding Strategies for Information-Centric Heterogeneous Vehicular Networks

in 11th IEEE Vehicular Networking Conference (VNC 2019) (2019)

Content downloading of mobile broadband users today routinely causes network load to exceed what the Radio Access Network (RAN) can sustain without degrading user experience. Many works are therefore ... [more ▼]

Content downloading of mobile broadband users today routinely causes network load to exceed what the Radio Access Network (RAN) can sustain without degrading user experience. Many works are therefore considering edge or fog computing paradigms and Device to Device (D2D) communication using 4G/5G C-V2X or IEEE 802.11p/bd links to obtain content. When content originates (or is maintained) at a central location, however, this requires expensive seeding of the content into the mobile network. We thus advocate basing the decision of when and where to perform fog seeding on a network graph that respects connectivity metrics while performing community detection and exploiting node centrality. We present different seeding strategies and investigate their respective benefits compared to traditional information-centric networking. Using simulations, we demonstrate that choosing a suitable strategy can yield substantial benefits - and vice versa. [less ▲]

Duplicate Suppression for Efficient Floating Car Data Collection in Heterogeneous LTE-DSRC Vehicular Networks

in Computer Communications (2018), 123

Collecting data from a large number of agents scattered over a region of interest is becoming an increasingly appealing paradigm to feed big data archives that lay the ground for a vast array of ... [more ▼]

Collecting data from a large number of agents scattered over a region of interest is becoming an increasingly appealing paradigm to feed big data archives that lay the ground for a vast array of applications. Vehicular Floating Car Data (FCD) collection is a major representative of this paradigm. Massive data collection from floating vehicles is the key to Intelligent Transportation Systems. We address the design and performance evaluation of a data collection protocol for the use case of periodic data collection. We target robustness, optimizing the amount of data and the value of the collection period, keeping in mind the goals of autonomous node operation and minimal coordination effort. From a system point of view, we believe that best solutions should jointly exploit the Long Term Evolution (LTE) cellular access network and the Dedicated Short-Range Communication (DSRC) based Vehicular Ad Hoc Network (VANET). Through a detailed comparative analysis, we show that such a hybrid approach offers superior performance, especially as for offloading the cellular radio access. A lightweight signaling procedure is designed, based on the DSRC VANET, which is able to avoid most of the duplicated data records, even if a distributed operation approach is pursued. The impact of the proposed protocol on the VANET load is evaluated and proved to be quite small, so that it does not interfere with other VANET-specific messages. [less ▲]

Poster: Performance Evaluation of an Open-Source Audio-Video Bridging/Time-Sensitive Networking Testbed for Automotive Ethernet

Poster (2018)

Automotive Ethernet (AE) is becoming more and more relevant to the automotive industry due to its support of emerging in-car applications, which have high bandwidth demands and stringent requirements in ... [more ▼]

Automotive Ethernet (AE) is becoming more and more relevant to the automotive industry due to its support of emerging in-car applications, which have high bandwidth demands and stringent requirements in terms of latency and time synchronization. One of the standards under consideration for AE is IEEE 802.1 Audio Video Bridging (AVB)/Time Sensitive Networking (TSN) that provides deterministic data link layer and bounded latency to real-time traffic classes. So far, this protocol stack has only been evaluated using either simulations or proprietary and expensive platforms. In this paper, we design a real testbed system for AE using general-purpose single-board computers and conduct experiments to assess the real-time performance of an open-source AVB/TSN implementation. Our preliminary results show that even under heavy load, AVB/TSN can fulfil the latency requirements of AE while keeping a constant latency variation. [less ▲]

Heterogeneous cellular and DSRC networking for Floating Car Data collection in urban areas

in Vehicular Communications (2017), 8

Vehicular traffic monitoring is a major enabler for a whole range of Intelligent Transportation System services. Real time, high spatial and temporal resolution vehicular traffic monitoring is becoming a ... [more ▼]

Vehicular traffic monitoring is a major enabler for a whole range of Intelligent Transportation System services. Real time, high spatial and temporal resolution vehicular traffic monitoring is becoming a reality thanks to the variety of communication platforms that are being deployed. Dedicated Short Range Communications (DSRC) and cellular communications like Long Term Evolution (LTE) are the major technologies. The former is specifically tailored for Vehicular Ad-hoc Network, the second one is pervasive. We propose a fully distributed Floating Car Data (FCD) collection protocol that exploits the heterogeneous network provided by DSRC and LTE. The proposed approach adapts automatically to the penetration degree of DSRC, achieving the maximum possible LTE offloading, given the VANET connectivity achieved via DSRC. Extensive simulations in real urban scenarios are used to evaluate the protocol performance and LTE offloading, as compared to baseline and literature approaches. [less ▲]

LTE floating car data application off-loading via VANET driven clustering formation

in 12th Annual Conference on Wireless On-demand Network Systems and Services (WONS) (2016, January)

Floating Car Data (FCD) applications are based on the collection of geo-localized information updates that are issued by vehicles roaming in a given area. These data are an essential source for traffic ... [more ▼]

Floating Car Data (FCD) applications are based on the collection of geo-localized information updates that are issued by vehicles roaming in a given area. These data are an essential source for traffic information and are widely employed by Intelligent Transportation Systems (ITS). We present and examine a hybrid networking architecture and protocol that are used for the efficient execution of such a collection process. We employ a VANET-based multihop dissemination logic to spread control messages and elect designated nodes. Those nodes are exploited to report vehicular data via LTE communications. The performance behavior of the proposed protocol is evaluated through the consideration of two real urban scenarios. In comparing with performance bounds that characterize the performance behavior attained by state-of-theart hybrid integrated VANET and LTE mechanisms, we show our approach to offer a substantial reduction in the traffic load rates induced over the LTE cellular radio access system. [less ▲]