cISP: A Speed-of-Light Internet Service Provider

Low latency is a requirement for a variety of interactive network applications. The Internet, however, is not optimized for latency. We thus explore the design of cost-effective wide-area networks that move data over paths very close to great-circle paths, at speeds very close to the speed of light in vacuum. Our cISP design augments the Internet's fiber with free-space wireless connectivity. cISP addresses the fundamental challenge of simultaneously providing low latency and scalable bandwidth, while accounting for numerous practical factors ranging from transmission tower availability to packet queuing. We show that instantiations of cISP across the contiguous United States and Europe would achieve mean latencies within 5% of that achievable using great-circle paths at the speed of light, over medium and long distances. Further, we estimate that the economic value from such networks would substantially exceed their expense

Modeling and Analysis of K-Tier Downlink Heterogeneous Cellular Networks

Cellular networks are in a major transition from a carefully planned set of large tower-mounted base-stations (BSs) to an irregular deployment of heterogeneous infrastructure elements that often additionally includes micro, pico, and femtocells, as well as distributed antennas. In this paper, we develop a tractable, flexible, and accurate model for a downlink heterogeneous cellular network (HCN) consisting of K tiers of randomly located BSs, where each tier may differ in terms of average transmit power, supported data rate and BS density. Assuming a mobile user connects to the strongest candidate BS, the resulting Signal-to-Interference-plus-Noise-Ratio (SINR) is greater than 1 when in coverage, Rayleigh fading, we derive an expression for the probability of coverage (equivalently outage) over the entire network under both open and closed access, which assumes a strikingly simple closed-form in the high SINR regime and is accurate down to -4 dB even under weaker assumptions. For external validation, we compare against an actual LTE network (for tier 1) with the other K-1 tiers being modeled as independent Poisson Point Processes. In this case as well, our model is accurate to within 1-2 dB. We also derive the average rate achieved by a randomly located mobile and the average load on each tier of BSs. One interesting observation for interference-limited open access networks is that at a given SINR, adding more tiers and/or BSs neither increases nor decreases the probability of coverage or outage when all the tiers have the same target-SINR.Comment: IEEE Journal on Selected Areas in Communications, vol. 30, no. 3, pp. 550 - 560, Apr. 201

Business environment, clustering, and industry location : evidence from Indian cities

How do differences in the local business environment influence location of industry within countries? How do the benefits of a good business environment compare with those from good market access and agglomeration economies from industry clustering? The authors examine these questions by analyzing location decisions of individual firms. Using data from a recently completed survey of manufacturing firms in India, they find that both the local business environment and agglomeration economies significantly influence business location choices across cities. In particular, excessive regulation of labor and of other industrial activities reduces the probability of a business locating in a city. The authors'findings imply that in order to attract industrial activity, smaller or remoter cities need to offer even more attractive policy concessions or reforms to offset the effects of their relatively adverse (economic) geography. Their methodology pays special attention to the identification of agglomeration economies in the presence of unobserved sources of natural advantage.

Urban Air Mobility Market Study

The Booz Allen Team explored market size and potential barriers to Urban Air Mobility (UAM) by focusing on three potential markets – Airport Shuttle, Air Taxi, and Air Ambulance. We found that the Airport Shuttle and Air Taxi markets are viable, with a significant total available market value in the U.S. of $500 billion, for a fully unconstrained scenario. In this unconstrained best-case scenario, passengers would have the ability to access and fly a UAM at any time, from any location to any destination, without being hindered by constraints such as weather, infrastructure, or traffic volume. Significant legal and regulatory, weather, certification, public perception, and infrastructure constraints exist, which reduce the market potential for these applications to only about 0.5$2.5 billion, in the near term. However, we determined that these constraints can be addressed through ongoing intra-governmental partnerships, government and industry collaboration, strong industry commitment, and existing legal and regulatory enablers. We found that the Air Ambulance market is not a viable market if served by electric vertical takeoff and landing (eVTOL) vehicles due to technology constraints but may potentially be viable if a hybrid VTOL aircraft are utilized

Price Linkages of Russian Regional Markets

Exploiting time series of the cost of a staples basket across 75 Russian regions over 1994-2000, price linkages of the regions are analyzed with the use of Granger causality as a tool. Price linkages of Russian regions are found extensive: on average, an individual regional market is linked through prices with 62% of others. Neither isolated clusters of regions nor autarkic regions are revealed; each region is linked with all others either directly or indirectly, through a chain of no more than two intermediate regions. Spatial autocorrelation is found to be widespread, taking place in two thirds of regions.http://deepblue.lib.umich.edu/bitstream/2027.42/57219/1/wp839 .pd

Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic

Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic (March 25 - 27, 2018 -- The University of New Hampshire) paired two of NSF\u27s 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this event, participants assessed economic, environmental, and social impacts of Arctic change on New England and established convergence research initiatives to prepare for, adapt to, and respond to these effects. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt will affect trade, fisheries, tourism, coastal ecology, air and water quality, animal migration, and demographics not only in the Arctic but also in lower latitude coastal regions such as New England. With profound changes on the horizon, this is a critical opportunity for New England to prepare for uncertain yet inevitable economic and environmental impacts of Arctic change

The impact of climate change on global tropical storm damages

This paper constructs an integrated assessment model of tropical cyclones in order to quantify the impact that climate change may have on tropical cyclone damages in countries around the world. The paper relies on a tropical cyclone generator in each ocean and several climate models to predict tropical cyclones with and without climate change. A damage model is constructed to compute the resulting damage when a cyclone strikes each country. Economic development is expected to double global tropical cyclone damages because more will be in harm's way. Climate change is expected to double global damage again, causing an additional $54 billion of damage per year. The damage is projected to be concentrated in North America and eastern Asia but many Caribbean islands will suffer the highest damages per unit of GDP. Most of the increased damage will be caused by rare but very powerful storms.Climate Change Economics,Climate Change Mitigation and Green House Gases,Hazard Risk Management,Science of Climate Change,Global Environment Facility