Urban geography of digital networks

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Urban Studies and Planning, 2003.Includes bibliographical references.This dissertation examines the development of digital network infrastructure in the world's great cities at the turn of the 20th century. Drawing upon the concept of cities as information systems and techniques of communications geography, it analyzes how the physical components of digital networks were deployed in major urban areas during the 1990s. It finds that historical processes and pre-existing differences between places shaped the evolution of this infrastructure at multiple spatial scales; global, metropolitan, and neighborhood. As a result, rather than bringing about the "death of distance", digital network infrastructure actually reinforced many of the pre-existing differences between connected and disconnected places. With the telecom bust of 2000-2002, these differences were likely to persist for a decade or more. Yet just as the development of wired digital network infrastructure slowed, wireless technologies emerged as a more flexible, intuitive, and efficient form of connecting users to networks in everyday urban settings. As a result, an untethered model for digital networks emerged which combining the capacity and security of wired networks over long distances with the flexibility and mobility of wireless networks over short distances. This new hybrid infrastructure provided the technology needed to begin widespread experimentation with the creation of digitally mediated spaces, such as New York City's Bryant Park Wireless Network.by Anthony M. Townsend.Ph.D

Electric Co-operatives as Rural Retail Broadband Network Providers: Opportunities and Challenges

Multiple studies have shown that access to high-speed broadband networks significantly improves the economies, education, and lifestyle benefits in rural areas. Consequently, this dissertation seeks to show how electric co-operatives could be an effective means for providing rural and cash-poor communities with this vital access. It analyzes the history of electric co-operatives, the legislative and regulatory status of electric co-operatives, funding processes, and the current energy/telecommunications marketplace. In light of the opportunities presented, challenges regarding how they should be regulated, legislated, and funded are addressed as well

Alternative Network Deployments: Taxonomy, Characterization, Technologies, and Architectures

This document presents a taxonomy of a set of "Alternative Network Deployments" that emerged in the last decade with the aim of bringing Internet connectivity to people or providing a local communication infrastructure to serve various complementary needs and objectives. They employ architectures and topologies different from those of mainstream networks and rely on alternative governance and business models. The document also surveys the technologies deployed in these networks, and their differing architectural characteristics, including a set of definitions and shared properties. The classification considers models such as Community Networks, Wireless Internet Service Providers (WISPs), networks owned by individuals but leased out to network operators who use them as a low-cost medium to reach the underserved population, networks that provide connectivity by sharing wireless resources of the users, and rural utility cooperatives

Developing the ZigBee Based Data Payload Coding for Data Communication in Microgrids

A data coding is presented in this paper for ZigBee-based wireless data communication system for future microgrids. It is assumed that each microgrid has a central controller and each distributed generation unit in the microgrid has a local controller. The communication system is responsible for transmitting and receiving data amongst these controllers. This communication system is based on ZigBee technology, which has low cost and low power consumption. The required data to be transferred are defined and a suitable coding is also proposed. Finally, the number of transmitted symbols and the processing time delay of the proposed data coding are numerically analyzed

Peer-to-peer energy trading in electrical distribution networks

In response to the challenges posed by the increasing penetration of distributed generation from renewable energy sources and the increasing electricity retail prices with decreasing Feed-In Tariff rates, a new energy trading arrangement, “peer-to-peer (P2P) energy trading” has been proposed. It refers to the direct energy trading among consumers and prosumers in distribution networks, which is developed based on the “P2P economy” concept (also known as sharing economy). A hierarchical system architecture model has been proposed in order to identify and categorise the key elements and technologies involved in P2P energy trading. A P2P energy trading platform called “Elecbay” is designed. The P2P bidding is simulated using game theory. Test results in a grid-connected LV Microgrid with distributed generators and flexible demands show that P2P energy trading is able to improve the local balance of energy generation and consumption, and the enhanced variety of peers is able to further facilitate the balance. Two necessary control systems are proposed for the Microgrid with “Elecbay”. A voltage control system which combines droop control and on-load-tap-changer (OLTC) control is designed and simulated. Simulation results show that the proposed voltage control system is sufficient for supporting the P2P energy trading in the Microgrid. The total number of operation times of the OLTC is reduced with P2P energy trading compared to the reference scenario. The information and communication technology (ICT) infrastructures for the P2P bidding platform and the voltage control system are investigated. The information exchange among peers and other parties (Elecbay, distribution system operators, etc.) is designed based on TCP/IP protocol. Existing and private communication networks with different communication medium, bandwidths, etc., are modelled. Simulation results show that the existing ICT infrastructures are sufficient for supporting both the P2P energy trading platform and the voltage control system. Therefore, no large amount of additional investments are required