Abstract

Internet traffic from mobile users has been growing sharply. To meet the needs of those"br"users, it is important to expand capacity of networks that provide Internet access in cost effective"br"ways. This capacity has traditionally been provided by cellular networks. However,"br"expanding the capacity of those networks alone may not be the most cost-effective way to meet"br"the present and future growth of mobile Internet under some circumstances. In this dissertation,"br"we show that networks of connected vehicles can be an important way to complement the"br"capacity of cellular networks to provide mobile Internet access under several scenarios."br"Connected vehicles may soon be widely deployed, forming mesh networks of short-range"br"connections among vehicles and between vehicles and roadside infrastructure. These"br"connections are collectively referred to as vehicle-to-everything, or V2X. Deployment of"br"connected vehicles and infrastructure is primarily intended to enhance road safety, and the U.S."br"Department of Transportation has recently proposed a mandate of V2X devices in vehicles"br"using Dedicated Short Range Communications (DSRC) technology. Other applications are also"br"envisioned that include Internet access in vehicles connecting to roadside infrastructure serving"br"as gateways to the Internet."br"In this work, we find that V2X-based networks are more cost-effective than cellular to"br"provide Internet access, in scenarios which DSRC devices are mandated in vehicles to enhance"br"road safety. This is true initially for densely populated urban areas, but over time V2X-based"br"networks would be cost-effective in less populated areas as well, as long as Internet traffic or"br"penetration of V2X devices grow as expected."br"Local and state governments are expected to deploy roadside infrastructure for safety"br"applications. If that infrastructure is shared with Internet Service Providers for a fee, then V2XABSTRACT based networks are cost-effective in locations with even lower population densities than the"br"locations where it is cost-effective to deploy infrastructure for Internet access only. Moreover,"br"the sharing fee could help governments save in infrastructure costs. We find the pricing"br"strategies that maximize either cost-effectiveness or government savings. We estimate that"br"governments could save about one-fifth of the total cost to deploy safety infrastructure"br"nationwide in the U.S., if fees are set to maximize government savings. Although we find that"br"these prices may differ from the pricing strategy that maximizes cost-effectiveness, maximizing"br"government savings results in near-optimal cost-effectiveness."br"The U.S. Federal Communications Commission has allocated 75 MHz of spectrum to be"br"used exclusively by DSRC devices, and it has been hotly debated whether all or part of that"br"bandwidth should be shared with unlicensed devices. We find that it is highly efficient to share"br"any spectrum allocated to V2X communications beyond the portion of that spectrum that is"br"needed for safety-critical DSRC messages. V2X and unlicensed devices require up to 50% less"br"bandwidth on shared spectrum to achieve given throughputs, compared to V2X and unlicensed"br"devices using separate bands. We conclude that the spectrum available for V2X should be"br"maintained or increased, as long as much of that spectrum is shared with non-V2X devices."br"Conclusions are derived from an engineering-economic approach, in which part of the"br"assumptions are based on data from a citywide deployment of connected vehicles in Portugal."br"The data is used in a detailed and realistic packet-level simulation model of V2X-based"br"networks used to provide Internet access with DSRC technology. In some scenarios, the"br"simulation also includes unlicensed devices using Wi-Fi technology. The results of the network"br"simulation are then fed into engineering-economic models to compare costs of V2X-based"br"networks with costs of macrocellular networks to carry given amounts of Internet traffic, and to"br"estimate other measures such as government revenues and spectrum usage. Those measures"br"help inform decisions about where and when to deploy V2X-based networks, decisions about whether and how to promote public-private partnerships to deploy V2X infrastructure, and"br"decisions about sharing spectrum used for V2X communications with non-V2X devices. "br

Abstract

The aim of this thesis was to explore if, and then how, electric cars and buses can contribute to sustainable personal mobility. Electric vehicles have increasingly been seen as a potential sustainable solution for the transport sector due to their high energy efficiency, close to zero emissions in the use phase, and the possibility to be powered by electricity from renewable resources. However, there are concerns about future scarcity of resources (e.g. lithium and cobalt for batteries), vehicle range, costs, high energy use in the production of batteries, as well as insufficient scientific support for how electric vehicles could be a part of a transition towards sustainability regarding personal mobility.   The challenges for a fast transition towards sustainability are large and many. The transport sector is not contributing to such development, mainly due to emissions, use of fossil energy, and use of materials mined and recycled under unacceptable conditions. Furthermore, existing societal goals (e.g. fossil-fuel independent vehicle fleet by 2030 in Sweden, UN Agenda 2030, and the Paris agreement) are insufficient for sustainability and are not complemented by concrete plans or an approach for how to engage stakeholders and achieve coordinated actions for sustainability. The Framework for Strategic Sustainable Development includes a principled definition of sustainability that is necessary and sufficient for sustainability and procedural support for collaborative innovation for a strategic transition to fulfillment of that definition, which is why it has been used as an overarching methodology in this thesis.  The research verified through several studies conditions for how electric vehicles can play a vital role in a strategic transition of personal mobility towards sustainability. Through stakeholder collaboration (e.g. interviews and workshops), a vision for sustainable transport with a focus on electric vehicles and an initial development plan towards that vision were designed. Several life cycle focused studies investigated (through calculations and data collection from literature, life cycle databases, interviews and workshops) about environmental and social impacts and costs for electric cars and buses. The stakeholder collaboration, combined with conceptual modelling, also resulted in models for generic support for multi-stakeholder collaboration and planning for strategic sustainable development of transport systems and communities, and for how to include electric buses in the procurement model of public transport. The strategic sustainable development perspective of this thesis broadens the analysis beyond the more common focus on climate change issues and should be able to reduce the risk of sub-optimizations in community and transport system development when applied in that context. The generic support for multi-stakeholder collaboration could potentially also promote a more participatory democratic approach to community development, grounded in a scientific foundation. "p"Contact the author to receive a pdf of the full thesis (papers included): sven.boren@bth.se or telephone +46455385723.