A Distributed Token Passing Protocol for Time Constrained Data Gathering in VANETs

Francesco Chiti,Carlos Borrego,Francesca Nizzi,Romano Fantacci,Laura Pierucci

doi:10.3390/electronics8080823

Francesco Chiti, Carlos Borrego + Show 3 more

Open Access

https://doi.org/10.3390/electronics8080823

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Abstract

This paper proposes a novel approach for time constrained information gathering in a typical Vehicular Ad Hoc Network (VANET), based on a token passing scheme, adapted to wireless communications by creating a virtual ring where nodes are connected to a predecessor and a successor node. To address the typical fast topology changes of VANETs, we proposed a specific approach, called Tom Thumb that is a distributed protocol that node-by-node circulates a special packet, called token, which collects the information stored in each vehicle until returning to the first unit within a specified time constraint. The protocol has been properly designed in terms of (i) the more effective hop-by-hop and distributed heuristic implementing the objective function (ii) the token packet format, i.e., the syntax and semantics of its fields. Finally, the performance of the proposed approach is validated for different time constraints and numbers of vehicles, always pointing out a remarkable gain, especially in the presence of severe constraints, i.e., in terms of time deadline, collected information amount and success probability.

Highlights

Vehicular Ad Hoc Networks (VANETs) are a Mobile Ad Hoc Networks (MANETs) special case, typically allowing both Vehicle to Vehicle (V2V) or Vehicle to Infrastructure (V2I) wireless communications [1,2], to support complex Intelligent Transportation System (ITS) applications [3,4].The main feature of VANETs is represented by the constrained and correlated node mobility patterns, which in turn implies an extremely time-varying network topology, with network partitioning and merging
We investigate the performance in terms of the amount of collected information within a predefined time constraint, as expressed in Equation (2); in addition, the probability of token recovering has been derived
The main difference with respect to the proposed Tom Thumb (TT) scheme is that Heuristic 1 (Heu1) does not save the path and, when the return to the Traffic Light (TL) is triggered, the neighbours’ discovery procedure is still performed and the token packet is forwarded the best neighbour, which becomes Token Owner (TO)