#20 Sharing Connected Vehicle Infrastructure for Safety Applications, Smart City and Internet Access
- Principal Investigator
- Jon Peha
- Status
- Completed
- Start Date
- Jan. 1, 2017
- End Date
- Aug. 31, 2018
- Project Type
- Research Advanced
- Grant Program
- MAP-21 TSET National (2013 - 2018)
- Grant Cycle
- 2017 TSET UTC
- Visibility
- Public
Abstract
Use of connected vehicles to enhance traffic safety could vastly reduce traffic fatalities, but this requires the deployment of roadside communications infrastructure which comes at a considerable cost. At the same time, there is reason to deploy roadside communications infrastructure for other purposes, such as smart city applications, and Internet access. In general, this research explores how public-private infrastructure sharing arrangements might greatly reduce the cost to tax-payers of improving vehicular safety and of supporting smart cities, while also expanding the availability of a new way to provide low-cost Internet access. This includes the potential benefits and trade-offs of infrastructure-sharing arrangements and pricing strategies. The research focus this year will be on spectrum decisions that might affect infrastructure-sharing arrangements, including how much spectrum will be available to intelligent transportation systems, how much of that spectrum will be shared with other kinds of devices, and the technical rules by which sharing would occur.
Description
Traffic 21 began funding this research in 2016. This section will describe overall goals, what we are focusing on in 2016, what we could accomplish with one more year, and what we will accomplish with several more years. 7.1. Motivation Safety vehicle-to-infrastructure (V2I) applications could prevent many fatalities and injuries [1], but this requires extensive deployment of infrastructure. States and localities may lack the funds for deployment and operation of these roadside devices, which could cost billions of dollars [2]. Communications infrastructure is also needed for smart city applications, e.g. to allow low-power sensors embedded in bridges to send their stress readings back to city collection sites. It might be possible to greatly reduce the infrastructure cost paid by government if some of the same infrastructure used to improve vehicular safety and support smarty city applications is also used to provide Internet access over DSRC-based vehicular networks. There is no reason why passengers cannot use the capacity of vehicular networks to browse the web or stream movies when (and only when) that capacity is not needed for safety-related applications. Whenever this DSRC connectivity is available, it is a far less costly Internet access option than a cellular network. Indeed, with data from mobile devices doubling every 18 months, cellular providers are actively seeking new ways to offload traffic from macrocells when possible. However, use of vehicular networks for Internet access is only possible if roadside infrastructure exists that can serve as a gateway between the vehicular network and the Internet. Infrastructure for Internet access is different from infrastructure deployed for safety purposes, but perhaps similar enough to allow cost-effective sharing. If the benefits of sharing infrastructure, then multiple policies and business arrangements become possible: (i) government can deploy infrastructure for safety and smart city purposes, and charge commercial Internet service providers (ISPs) that use it, (ii) government can get some of the infrastructure it needs at lower cost by leasing access from commercial ISPs, or (iii) government and commercial ISPs can establish public-private partnerships to manage shared infrastructure. Today, no one knows whether such arrangements would be cost-effective. In a series of papers (such as [3, 4]), the PI investigated similar infrastructure sharing opportunities between wireless communications systems for public safety (e.g. firefighters, police, paramedics) and commercial cellular. His research at CMU demonstrated that many billions of dollars could be saved through different forms of infrastructure sharing. Later, while serving first as Chief Technologist in the Federal Communications Commission and then in the White House, he co-authored the plan to turn this proposal into reality. Congress passed the legislation in 2012. 7.2. Research Objectives Our primary goal is to determine the extent to which sharing of roadside infrastructure between safety applications and Internet access would reduce the cost of deploying and operating infrastructure for enhanced safety. We will examine how much money local, state and federal government could save when deploying safety infrastructure that is shared with commercial ISPs, how sharing can affect overall social welfare, how sharing can affect availability of smart city functions, and how all of the above objectives are affected by the specific sharing arrangements and pricing strategies. For example, Fig. 1 shows how a city might save more by charging ISPs more, although this may decrease DSRC-based Internet access and corresponding benefits, and this trade-off can be quantified. We will determine how benefits vary by region. In big cities, government agencies may receive substantial revenues from ISPs through sharing, but probably not in sparsely populated areas. For example, Fig. 2 shows our hypothesis of how revenues-cost per square km vary with population density. We will estimate how soon infrastructure sharing would be possible in various regions, as the cost effectiveness of Internet access through DSRC depends on penetration of DSRC devices in vehicles and Internet usage in equipped vehicles, both of which are expected to increase rapidly over time. We will examine how sensitive all of these estimates are to factors that are uncertain. Our work in 2016 will make limiting assumptions, including the following: (i) DSRC-based Internet access is offered by only one provider, so there is no market competition, and no contention caused by multiple firms that share spectrum, (ii) the amount of spectrum allocated by the FCC for intelligent transportation systems is fixed and not shared with other uses, and (iii) DSRC is embedded in cars only due to a Dept. of Transportation mandate, even though the possibility of using DSRC for Internet access could motivate some vehicle-owners to adopt ahead of a mandate. In 2017 -2020, we hope to drop these assumptions. No one knows how many providers of Internet access through DSRC will emerge, or the extent to which their devices will interoperate for functions not related to safety, and this could greatly affect how government should approach infrastructure sharing. (i) We will estimate the impact of increasing or decreasing the total amount of spectrum available for intelligent transportation systems. For example, Fig. 3 shows how increasing spectrum when there is infrastructure sharing with ISPs would lead to more benefit from DSRC-based Internet, as well as more cost for roadside units. Increasing spectrum will increase government cost savings and overall social welfare, but when is it enough to justify the cost of the spectrum itself? We will also consider the impact of allowing spectrum to be shared between vehicular networks and other uses such as Wi-Fi, both with an FCC-imposed requirement for cooperation and without such a requirement. Sharing without cooperation will generally harm vehicular networks, but if there is an FCC mandate to cooperate then the impact could positive or negative. (ii) With competition, sharing arrangements might involve many more parties. Does competition increase or decrease the benefits of infrastructure sharing? Should government approach sharing on a bilateral or multilateral basis? The availability of spectrum is also very much in question; testing of new spectrum-sharing paradigms is underway, and the FCC has an open proceeding that could lead to significant change. Any such change could greatly affect the cost-effectiveness of infrastructure sharing, as well as the effectiveness of safety-critical applications and the availability of DSRC-based Internet access. (iii) We will consider the possibility that vehicle-owners that wish to access the Internet at lower cost will voluntarily adopt DSRC, even when it is not yet required for safety purposes. In this way, DSRC-based Internet access may accelerate the adoption of technology that enhances safety, and infrastructure sharing could make this happen in parts of the country where it otherwise would not. We will adopt a game theoretic approach, and assume that each vehicle owner will adopt DSRC when there is no mandate if and only if the savings from DSRC-based Internet access exceeds the cost of DSRC, which depends on each user’s Internet usage, as well as how many other cars on the road already have DSRC, and other factors. For example, Fig. 4 shows the response curve of a game in which an ISP decides how many roadside units to share based on number of DSRC-equipped vehicles, and vehicle-owners who are not (yet) subject to mandate equip their vehicles based on how many ISP roadside units are available. We can then see how many owners voluntarily adopt at the equilibrium point, and how much the ISP would pay to share that much roadside infrastructure. 7.3. Methodology Our approach is threefold: (i) collect extensive data from a large deployed vehicular networks in Portugal, (ii) develop a detailed packet-level network simulation using this data that shows the relationship between infrastructure deployment strategies and achievable throughput, and (iii) develop economic models that relate costs and revenues to achievable throughputs and infrastructure strategies. Infrastructure strategies vary in number of roadside units per square km, and extent of sharing between infrastructure for safety and infrastructure for Internet access. We are developing packet-level simulation software that uses location data from more than 900 vehicles from Portugal, to simulate a mesh network comprised by DSRC-equipped vehicles that connect to roadside units (RSU) to gain access to the Internet. We will use this simulation to estimate the rate of Internet data that can be carried through the DSRC channels not occupied by safety messages, under different conditions. To estimate economic gain as a function of throughput, we assume that mobile devices can use either cellular services or networks of connected vehicles, and that every bit carried on the vehicular network is one less bit on the cellular network. In a capacity-limited cellular network, a reduction of data from mobile devices that must be carried in the busy hour allows each cell tower to provide adequate capacity over a larger area, thereby reducing the number of costly towers that a cellular operator needs to cover a given region. We define the benefit of offload in a given scenario as the cost savings from reducing the number of cell towers. This is compared to the costs of DSRC RSUs, which quantity is assumed to be the one that maximizes the difference between benefits and costs. To examine the impact of infrastructure sharing, we will estimate costs of deploying one infrastructure for safety and one for Internet, and compare that with costs obtained with different forms and levels of infrastructure sharing. We will estimate the cost difference between an individual RSU used for safety, an RSU used for Internet access and an RSU suitable for both uses, with different assumptions about shared backhaul, shared power, and more. To consider the impact of spectrum policy, we will redesign the packet-level simulation to support different amounts of spectrum and different types of sharing. In practice, the more spectrum allocated for intelligent transportation systems, the more likely that spectrum will be shared. In some scenarios, some or all of the spectrum used for intelligent transportation systems may also be used by devices that share without cooperation, meaning that they are sources of interference and congestion. In other scenarios, these devices cooperate, perhaps relaying a packet from a moving vehicle to a roadside unit, in accordance with the technical standard. To drop the assumption that there is only one infrastructure for Internet access and consider competition, we must change the simulation to support multiple mesh networks that do not cooperate and sometimes interfere with each other, and we much change the economic model to consider which ISPs pay for infrastructure, and which share with government. To drop the assumption that DSRC is deployed only when mandated, we must develop new game theoretic models.
Timeline
Phase 1, already underway. Analysis of benefits of infrastructure sharing in simple baseline scenario. We anticipate some results by the end of 2016 under current funding, and continued work in 2017 with new funding. Phase 2, which would begin in 2017, and be funded under this proposal: Analysis under different assumptions about spectrum availability and spectrum sharing. Phase 3: which is part of the longer-term vision. Analysis with more than one provider under different assumptions about competition, infrastructure and spectrum sharing, cooperation, and market share. Phase 4: which is part of the longer-term vision. 2019-2020. Analysis scenarios where adoption of DSRC can be voluntary.
Strategic Description / RD&T
Deployment Plan
Not directly applicable. For this research, practical impact comes in part from outreach to policymakers rather than “deployment” per se. This particularly includes policymakers at the Federal Communications Commission and the U.S. Department of Transportation, as well as other agencies. As a result we anticipate roughly one presentation to policymakers per year to be held in Washington DC.
Expected Outcomes/Impacts
As discussed in Section 7, over the course of this multi-phase project, we expect to produce concreate analysis that will inform important policy decisions by providing quantitative answers to the following questions. With one more year of additional funding, we hope to address the following. • For local infrastructure decision-makers: Under what circumstances should city or regional agencies decide to share roadside infrastructure for vehicular safety and perhaps for smart city applications with Internet service providers? What sharing and pricing arrangements should be considered, and what are the tradeoffs? • For federal infrastructure decision-makers: What is the potential for infrastructure sharing to reduce the costs of infrastructure needed for safety and smart cities on a nationwide basis, and to what extent is this balanced from region to region? • Spectrum: What is the impact of spectrum policy on intelligent transportation systems in general and infrastructure sharing arrangements in particular? What spectrum policy decisions lead to good outcomes? How do spectrum policy decisions affect decisions that should be made with respect to infrastructure deployment, infrastructure sharing, and pricing strategies? With several years of funding beyond, we hope to address the following. • Competition: How does the extent of competition affect the government’s ability to save on the cost of infrastructure? To what extent is competition among providers of DSRC-based Internet access sustainable with and without cooperative spectrum sharing techniques? Thus, how does the FCC’s decision on whether to require cooperation in the band affect the ability to defray infrastructure costs through sharing? • Mandates: If DSRC-based Internet access becomes available, to what extent will this cause vehicle-owners to adopt DSRC ahead of any mandate from the Dept. of Transportation? How should this affect decisions regarding infrastructure sharing, and decisions regarding mandates and their timing?
Expected Outputs
TRID
Individuals Involved
| Name | Affiliation | Role | Position | |
|---|---|---|---|---|
| aligo@cmu.edu | Ligo, Alexandre | EPP | Other | Student - PhD |
| peha@cmu.edu | Peha, Jon | ECE/EPP | PI | Faculty - Research/Systems |
Budget
Amount of UTC Funds Awarded
$127500.00Total Project Budget (from all funding sources)
$127500.00Documents
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