653 research outputs found
Scaling Laws for Vehicular Networks
Equipping automobiles with wireless communications and networking capabilities is becoming the frontier in the evolution to the next generation intelligent transportation systems (ITS). By means of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications, information generated by the vehicle-borne computer, vehicle control system, on-board sensors, or roadside infrastructure, can be effectively disseminated among vehicles/infrastructure in proximity or to vehicles/infrastructure multiple hops away, known as vehicular networks (VANETs), to enhance the situational awareness of vehicles and provide motorist/passengers with an information-rich travel environment. Scaling law for throughput capacity and delay in wireless networks has been considered as one of the most fundamental issues, which characterizes the trend of throughput/delay behavior when the network size increases. The study of scaling laws can lead to a better understanding of intrinsic properties of wireless networks and theoretical guidance on network design and deployment. Moreover, the results could also be applied to predict network performance, especially for the large-scale vehicular networks. However, map-restricted mobility and spatio-temporal dynamics of vehicle density dramatically complicate scaling laws studies for VANETs. As an effort to lay a scientific foundation of vehicular networking, my thesis investigates capacity scaling laws for vehicular networks with and without infrastructure, respectively.
Firstly, the thesis studies scaling law of throughput capacity and end-to-end delay for a social-proximity vehicular network, where each vehicle has a restricted mobility region around a specific social spot and services are delivered in a store-carry-and-forward paradigm. It has been shown that although the throughput and delay may degrade in a high vehicle density area, it is still possible to achieve almost constant scaling for per vehicle throughput and end-to-end delay.
Secondly, in addition to pure ad hoc vehicular networks, the thesis derives the capacity scaling laws for networks with wireless infrastructure, where services are delivered uniformly from infrastructure to all vehicles in the network. The V2V communication is also required to relay the downlink traffic to the vehicles outside the coverage of infrastructure. Three kinds of infrastructures have been considered, i.e., cellular base stations, wireless mesh backbones (a network of mesh nodes, including one mesh gateway), and roadside access points. The downlink capacity scaling is derived for each kind of infrastructure. Considering that the deployment/operation costs of different infrastructure are highly variable, the capacity-cost tradeoffs of different deployments are examined. The results from the thesis demonstrate the feasibility of deploying non-cellular infrastructure for supporting high-bandwidth vehicular applications.
Thirdly, the fundamental impact of traffic signals at road intersection on drive-thru Internet access is particularly studied. The thesis analyzes the time-average throughput capacity of a typical vehicle driving through randomly deployed roadside Wi-Fi networks. Interestingly, we show a significant throughput gain for vehicles stopping at intersections due to red signals. The results provide a quick and efficient way of determining the Wi-Fi deployment scale according to required quality of services.
In summary, the analysis developed and the scaling laws derived in the thesis provide should be very useful for understanding the fundamental performance of vehicular networks
Road-side units operators in competition: A game-theoretical approach
International audienceWe study the interactions among Internet providers in vehicular networks which offer access to commuters via road side units (RSUs). Namely, we propose a game-theoretical framework to model the competition on prices between vehicular Internet providers to capture the largest amount of users, thus selfishly maximizing the revenues. The equilibria of the aforementioned game are characterized under different mobile traffic conditions, RSU capabilities and users requirements and expectations. In particular, we also consider in the analysis the case where mobile users modify the price they accept to pay for the access as the likeliness of finding an access solution decreases. Our game-theoretical analysis gives insights on the outcomes of the competition between vehicular Internet providers, further highlighting some counter-intuitive behaviors; as an example, comparing with the case when users have constant price valuation over time, having users inclined to increasing their "acceptable" price may force vehicle Internet providers to charge lower prices due to competition
Performance Assessment of Aggregation and Deaggregation Algorithms in Vehicular Delay-Tolerant Networks
Vehicular Delay-Tolerant Networks (VDTNs) are a new approach for vehicular
communications where vehicles cooperate with each other, acting as the
communication infrastructure, to provide low-cost asynchronous opportunistic
communications. These communication technologies assume variable delays
and bandwidth constraints characterized by a non-transmission control protocol/
internet protocol architecture but interacting with it at the edge of the
network.
VDTNs are based on the principle of asynchronous communications, bundleoriented
communication from the DTN architecture, employing a store-carryand-
forward routing paradigm. In this sense, VDTNs should use the tight network
resources optimizing each opportunistic contact among nodes.
At the ingress edge nodes, incoming IP Packets (datagrams) are assembled
into large data packets, called bundles. The bundle aggregation process plays
an important role on the performance of VDTN applications. Then, this paper
presents three aggregation algorithms based on time, bundle size, and a hybrid
solution with combination of both. Furthermore, the following four aggregation
schemes with quality of service (QoS) support are proposed: 1) single-class bundle
with N = M, 2) composite-class bundle with N = M, 3) single-class bundle
with N > M, and 4) composite-class bundle with N > M, where N is the number
of classes of incoming packets and M is the number of priorities supported
by the VDTN core network. The proposed mechanisms were evaluated through
a laboratory testbed, called VDTN@Lab. The adaptive hybrid approach and the
composite-class schemes present the best performance for different types of
traffic load and best priorities distribution, respectively
Spartan Daily, November 22, 1999
Volume 113, Issue 59https://scholarworks.sjsu.edu/spartandaily/9488/thumbnail.jp
Vehicular networking in the recursive internetwork architecture
Vehicles such as cars are expected to use communication technologies for retrieving different kinds of information and exchanging information with other vehicles for safety and infotainment purposes. This results in vehicular networks, where vehicles can connect to other vehicles or communication infrastructures such as Road Side Units. The Recursive Inter- Network Architecture (RINA) has been proposed as a Future Internet architecture. This paper investigates and analyses how vehicular networks can be supported by RINA and how a RINA based vehicular network architecture can be designed to support efficient management of mobile vehicles.Peer ReviewedPostprint (author's final draft
American Square Dance Vol. 53, No. 9 (Sep. 1998)
Monthly square dance magazine that began publication in 1945
Daily Eastern News: November 18, 2014
https://thekeep.eiu.edu/den_2014_nov/1011/thumbnail.jp
The BG News July 6, 2005
The BGSU campus student newspaper July 6, 2005. Volume 95 - Issue 156https://scholarworks.bgsu.edu/bg-news/8453/thumbnail.jp
The BG News April 5, 2000
The BGSU campus student newspaper April 5, 2000. Volume 85 - Issue 55https://scholarworks.bgsu.edu/bg-news/7636/thumbnail.jp
The BG News March 11, 2013
The BGSU campus student newspaper, March 11, 2013 Volume 92 - Issue 75https://scholarworks.bgsu.edu/bg-news/9611/thumbnail.jp
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