Performance Analysis of Smartphone-based Mobile Wi-Fi Hotspots Operating in a Congested Environment

In this work, we address the ubiquity of internet connections in smart cities by analyzing mobile Wi-Fi hotspots in terms of speed and energy efficiency in a congested Wi-Fi environment. We consider state-of-theart consumer smartphones in our work since they are the major devices in establishing mobile Wi-Fi hotspots nowadays. There are two main wireless connections in mobile Wi-Fi hotspots, the cellular connection and the Wi-Fi connection. It has been known that the speed of WiFi connections enormously supersedes the speed of cellular connections with the use of present technologies of each. In this work, we show that this well-known fact becomes controversial when establishing mobile Wi-Fi hotspots using smartphones in a nowadays typical congested Wi-Fi environment

Resource allocation techniques for heterogeneous networks under user misbehavior

©2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.In this letter we focus on the uplink offloading with IP Flow Mobility (IFOM). With IFOM a User Equipment (UE) is able to maintain concurrently two data streams, one through LTE and the other through WiFi. We consider the existence of malicious UEs that aim to exploit the WiFi bandwidth against their truthful peers, in order to upload less data through the energy demanding LTE uplink and a reputation based method is proposed to combat the selfish operation. The WiFi bandwidth is allocated based on weighted proportional fairness and the LTE rate is defined through an exponential pricing algorithm. We theoretically analyse our approach and evaluate the performance of the malicious and the truthful UEs in terms of energy efficiency and throughput, through simulations. We show that while the malicious UEs present better energy efficiency before being detected, their performance is significantly degraded with the proposed reaction method.Peer ReviewedPostprint (author's final draft

A Multi-Carrier Collaborative Solution to Minimize Connectivity-loss

Nearly two-thirds of Americans own a smart phone, and 19% of Americans rely on their smartphone for either accessing valuable information or staying connected with their friends and family across the globe [15]. Staying always-on and always-connected to the Internet is one of the most important and useful features of a smartphone. This connection is used by almost every single application on the device including web browsers, email clients, messaging applications, etc. Unfortunately, the cellular networks on our smartphones are not perfect and do not always have cellular signal. Our devices often lose Internet connection when users are on the go and traveling. This thesis presents a novel in-depth implementation and evaluation of what we can achieve when a user loses network connectivity. BleHttp, a library for Android, was developed that uses Bluetooth Low Energy to connect to other devices using a different carrier within close proximity of each other and make HTTP requests. In our results, we saw 100% success rates on HTTP requests with connected devices on a good connection. Average round trip times were tested to be as low as 1.5 seconds

Robotic Wireless Sensor Networks

In this chapter, we present a literature survey of an emerging, cutting-edge, and multi-disciplinary field of research at the intersection of Robotics and Wireless Sensor Networks (WSN) which we refer to as Robotic Wireless Sensor Networks (RWSN). We define a RWSN as an autonomous networked multi-robot system that aims to achieve certain sensing goals while meeting and maintaining certain communication performance requirements, through cooperative control, learning and adaptation. While both of the component areas, i.e., Robotics and WSN, are very well-known and well-explored, there exist a whole set of new opportunities and research directions at the intersection of these two fields which are relatively or even completely unexplored. One such example would be the use of a set of robotic routers to set up a temporary communication path between a sender and a receiver that uses the controlled mobility to the advantage of packet routing. We find that there exist only a limited number of articles to be directly categorized as RWSN related works whereas there exist a range of articles in the robotics and the WSN literature that are also relevant to this new field of research. To connect the dots, we first identify the core problems and research trends related to RWSN such as connectivity, localization, routing, and robust flow of information. Next, we classify the existing research on RWSN as well as the relevant state-of-the-arts from robotics and WSN community according to the problems and trends identified in the first step. Lastly, we analyze what is missing in the existing literature, and identify topics that require more research attention in the future