Energy-Efficient Design of Adhoc and Sensor Networks

Adhoc and sensor networks (ASNs) are emerging wireless networks that are expected to have significant impact on the efficiency of many military and civil applications. However, building ASNs efficiently poses a considerable technical challenge because of the many constraints imposed by the environment, or by the ASN nodes capabilities themselves. One of the main challenges is the finite supply energy.Since the network hosts are battery operated, they need to be energy conserving so that the nodes and hence the network itself does not expire. In this thesis different techniques for anenergy-efficient design for ASNs are presented. My work spans two layers of the network protocol stack; these are the Medium Access Layer (MAC) and the Routing Layer. This thesis first identifies and highlights the different sources of energy inefficiency in ASNs, and then it describes how each of these inefficiencies is handled. Toward this goal, I first focus on the Medium Access (MAC) Layer and present my work that handles the wasted energy in transmission and describe how the transmission distance is optimized to extend the network lifetime. I then describe BLAM, an energy-efficient extension for the IEEE 802.11, that handles the wasted energy in collisions. Next, TDMA-ASAP, a new MAC protocol for sensor networks, is introduced. TDMA-ASAP targets the wasted energy in idle listening. I also investigate energy-efficiency at the routing layer level. First, the ``Flooding-Waves' problem is identified. This is a problem in any cost-based energy-efficient routing protocol for adhoc networks, different ways of solving this problem are presented. For sensor networks routing trees are usually used, I introduce a new routing scheme called RideSharing which is energy-efficient and fault-tolerant. RideSharing will deliver a better aggregate result to the end user while masking network linkfailures. Next, I present how to extend the RideSharing scheme to handle different link quality models. Finally, I introduce GroupBeat,a new health detection system for sensor networks, which when combined with RideSharing can deliver the information to the end user even in case of node failures

Internet Interconnection Ecosystem in Finland

For both fixed and mobile network operators, interconnection constitutes an indisputably key element to provide end users with a variety of services. Internet interconnection is particularly an intriguing subject due to the importance of the Internet in our everyday lives and our genuine curiosity to grasp its underlying structure. This thesis aims to provide a holistic approach to study the Internet interconnections in a nation-centric stance. To accomplish the objective, initially the method that breaks down the key features of the interconnection analysis is introduced. The nation-centric analysis is conducted for Finland by jointly utilizing the Internet registry data and collected Internet routing data. Covering the last decade of the Finnish Internet, the longitudinal analysis yields significant findings for the Internet address usage statistics and the level of multi-homed networks, along with the classification and inference of relationships between stakeholders in the interconnection ecosystem. The implications that the emerging interconnection models pose for the future global service delivery among both fixed and mobile networks are expounded from the perspective of the existing domestic interconnection practices. The longitudinal interconnectivity study allows us to comprehend both technical and business interfaces between market players by revealing a complete list of customer-provider relationships. Within a national milieu, the assessment of the current Internet market dynamics and future implications of emerging models can be considered in more rationally anticipated manner. Hence, authorities who desire to design new pricing schemes and policies for future networking interconnections can be guided more thoroughly

Measuring Effectiveness of Address Schemes for AS-level Graphs

This dissertation presents measures of efficiency and locality for Internet addressing schemes. Historically speaking, many issues, faced by the Internet, have been solved just in time, to make the Internet just work~\cite{justWork}. Consensus, however, has been reached that today\u27s Internet routing and addressing system is facing serious scaling problems: multi-homing which causes finer granularity of routing policies and finer control to realize various traffic engineering requirements, an increased demand for provider-independent prefix allocations which injects unaggregatable prefixes into the Default Free Zone (DFZ) routing table, and ever-increasing Internet user population and mobile edge devices. As a result, the DFZ routing table is again growing at an exponential rate. Hierarchical, topology-based addressing has long been considered crucial to routing and forwarding scalability. Recently, however, a number of research efforts are considering alternatives to this traditional approach. With the goal of informing such research, we investigated the efficiency of address assignment in the existing (IPv4) Internet. In particular, we ask the question: ``how can we measure the locality of an address scheme given an input AS-level graph?\u27\u27 To do so, we first define a notion of efficiency or locality based on the average number of bit-hops required to advertize all prefixes in the Internet. In order to quantify how far from ``optimal the current Internet is, we assign prefixes to ASes ``from scratch in a manner that preserves observed semantics, using three increasingly strict definitions of equivalence. Next we propose another metric that in some sense quantifies the ``efficiency of the labeling and is independent of forwarding/routing mechanisms. We validate the effectiveness of the metric by applying it to a series of address schemes with increasing randomness given an input AS-level graph. After that we apply the metric to the current Internet address scheme across years and compare the results with those of compact routing schemes

Internet of Things From Hype to Reality

The Internet of Things (IoT) has gained significant mindshare, let alone attention, in academia and the industry especially over the past few years. The reasons behind this interest are the potential capabilities that IoT promises to offer. On the personal level, it paints a picture of a future world where all the things in our ambient environment are connected to the Internet and seamlessly communicate with each other to operate intelligently. The ultimate goal is to enable objects around us to efficiently sense our surroundings, inexpensively communicate, and ultimately create a better environment for us: one where everyday objects act based on what we need and like without explicit instructions

Education handbook

2003 handbook for the faculty of Educatio

Mobile Ad-Hoc Networks

Being infrastructure-less and without central administration control, wireless ad-hoc networking is playing a more and more important role in extending the coverage of traditional wireless infrastructure (cellular networks, wireless LAN, etc). This book includes state-of the-art techniques and solutions for wireless ad-hoc networks. It focuses on the following topics in ad-hoc networks: vehicular ad-hoc networks, security and caching, TCP in ad-hoc networks and emerging applications. It is targeted to provide network engineers and researchers with design guidelines for large scale wireless ad hoc networks

Bowdoin College Catalogue and Academic Handbook (2020-2021)

https://digitalcommons.bowdoin.edu/course-catalogues/1318/thumbnail.jp

Bowdoin College Catalogue and Academic Handbook (2019-2020)

https://digitalcommons.bowdoin.edu/course-catalogues/1304/thumbnail.jp

Arts handbook

2003 handbook for the faculty of Art