Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

An Experimental Investigation of Hyperbolic Routing with a Smart Forwarding Plane in NDN

Routing in NDN networks must scale in terms of forwarding table size and routing protocol overhead. Hyperbolic routing (HR) presents a potential solution to address the routing scalability problem, because it does not use traditional forwarding tables or exchange routing updates upon changes in network topologies. Although HR has the drawbacks of producing sub-optimal routes or local minima for some destinations, these issues can be mitigated by NDN's intelligent data forwarding plane. However, HR's viability still depends on both the quality of the routes HR provides and the overhead incurred at the forwarding plane due to HR's sub-optimal behavior. We designed a new forwarding strategy called Adaptive Smoothed RTT-based Forwarding (ASF) to mitigate HR's sub-optimal path selection. This paper describes our experimental investigation into the packet delivery delay and overhead under HR as compared with Named-Data Link State Routing (NLSR), which calculates shortest paths. We run emulation experiments using various topologies with different failure scenarios, probing intervals, and maximum number of next hops for a name prefix. Our results show that HR's delay stretch has a median close to 1 and a 95th-percentile around or below 2, which does not grow with the network size. HR's message overhead in dynamic topologies is nearly independent of the network size, while NLSR's overhead grows polynomially at least. These results suggest that HR offers a more scalable routing solution with little impact on the optimality of routing paths

Teleoperation of passivity-based model reference robust control over the internet

This dissertation offers a survey of a known theoretical approach and novel experimental results in establishing a live communication medium through the internet to host a virtual communication environment for use in Passivity-Based Model Reference Robust Control systems with delays. The controller which is used as a carrier to support a robust communication between input-to-state stability is designed as a control strategy that passively compensates for position errors that arise during contact tasks and strives to achieve delay-independent stability for controlling of aircrafts or other mobile objects. Furthermore the controller is used for nonlinear systems, coordination of multiple agents, bilateral teleoperation, and collision avoidance thus maintaining a communication link with an upper bound of constant delay is crucial for robustness and stability of the overall system. For utilizing such framework an elucidation can be formulated by preparing site survey for analyzing not only the geographical distances separating the nodes in which the teleoperation will occur but also the communication parameters that define the virtual topography that the data will travel through. This survey will first define the feasibility of the overall operation since the teleoperation will be used to sustain a delay based controller over the internet thus obtaining a hypothetical upper bound for the delay via site survey is crucial not only for the communication system but also the delay is required for the design of the passivity-based model reference robust control. Following delay calculation and measurement via site survey, bandwidth tests for unidirectional and bidirectional communication is inspected to ensure that the speed is viable to maintain a real-time connection. Furthermore from obtaining the results it becomes crucial to measure the consistency of the delay throughout a sampled period to guarantee that the upper bound is not breached at any point within the communication to jeopardize the robustness of the controller. Following delay analysis a geographical and topological overview of the communication is also briefly examined via a trace-route to understand the underlying nodes and their contribution to the delay and round-trip consistency. To accommodate the communication channel for the controller the input and output data from both nodes need to be encapsulated within a transmission control protocol via a multithreaded design of a robust program within the C language. The program will construct a multithreaded client-server relationship in which the control data is transmitted. For added stability and higher level of security the channel is then encapsulated via an internet protocol security by utilizing a protocol suite for protecting the communication by authentication and encrypting each packet of the session using negotiation of cryptographic keys during each session

Design of an Integrated SDN/NFV management and orchestration architecture

This project aims at explaining and defining the SDN technology with integration of the NFV technology. We will also see the logic of this technology applied to a program designed for this project. The objective of this project is to understand the purpose of this technology, where is it going to be used, why companies like Google or Microsoft for over 2 years have been investing time and resources to develop and to implement the technology on the corporate level, as well as on the level of regular user like you and me. Firstly we will focus on the explanation of the SDN technology, what it is, what for is it going to be used and what is the future of this technology. Why the SDN is so important? Next, we will explain the use of the NFV and show how it is going to change the way we see the network right now. NFV also works with the SDN. Once we define the basics of the two technologies, we will proceed to the explanation of the practical part of this project. I would like to comment on the software used for this project is open source, since the OS used on the machine that carried out the simulations, and wrote this lines, to the package Rstudio. The practical part is to simulate how will work the network flows when this technology is used. The program will optimize the resources that we want for the proper performance of the global system. For example, we can optimize the path, the number of machines the flow has to cross, optimize the global delay of the flow, etc. Finally, we will reach specific conclusions based on the work we have done, as well as some personal outcome, such as the analysis of the difficulties encountered during the performance, as well as training and finally knowledge gained through work

Social media and self-control: The vices and virtues of attention

Self-control, the capacity to resist temptations and pursue longer-term goals over immediate gratifications, is crucial in determining the overall shape of our lives, and thereby in our ability to shape our identities. As it turns out, this capacity is intimately linked with our ability to control the direction of our attention. This raises the worry that perhaps social media are making us more easily distracted people, and therefore less able to exercise self-control. Is this so? And is it necessarily a bad thing? This paper analyzes the nature of attention, its vices and virtues, and what currently available evidence has to say about the effects of social media on attention and self-control. The pattern that seems to be emerging is that, although there is an association between higher use of social media and lower attentional control, we do not yet know whether it is social media use that makes people more distracted, or whether those who use social media the most do so because they are more easily distracted. Either way, the rise of the ‘Web 2.0’ does raise questions about whether the virtues of attention will change in the future, and whether this will bring with it a transformation in the way we shape our selves

Research Highlights

Research Highlights was a newsletter highlighting the research being done at the Boston University School of Management (Questrom School of Business)