Abstract
The rise of the Internet of Things and the growth of the IP cameras market are making Wireless Video Sensor Networks (WVSNs) popular. In turn, Wi-Fi is becoming the enabling technology for WVSNs due to its flexibility, high bitrates provided and low cost; however, these networks suffer from three major problems: bad performance, throughput unfairness, and energy inefficiency. In order to address the lack of holistic solutions to solve these problems, we propose the FM-WiFIX+ solution. This solution uses FM radio as an out-of-band control channel to signal when a video sensor should turn its IEEE 802.11 interface OFF, thus saving energy. The results obtained with a proof-of-concept prototype show that for a network with 7 nodes the proposed solution can achieve gains of energy up to 48 %, while maintaining good levels of performance and throughput fairness.

Abstract
Peer-to-Peer networks are extensively used for largescale file sharing. As more information flows through these networks, people are becoming increasingly concerned about their privacy. Traditional P2P file sharing systems provide performance and scalability at the cost of requiring peers to publicly advertise what they download. Several P2P privacyenhancing systems have been proposed but they still require peers to advertise, either fully or partially, what they download. Lacking alternatives, users have adopted anonymity systems for P2P file sharing, misunderstanding the privacy guarantees provided by such systems, in particular when relaying traffic of insecure applications such as BitTorrent. Our goal is to prevent any malicious peer(s) from ascertaining users' content interests so that plausible deniability always applies. We propose a novel P2P file sharing model, Mistrustful P2P, that (1) supports file sharing over open and untrustworthy P2P networks, (2) requires no trust between users by avoiding the advertisement of what peers download or miss, and (3) still ensures deterministic protection of user's interests against attacks of size up to a configured privacy protection level. We hope that our model can pave the ground for a new generation of privacyenhancing systems that take advantage of the new possibilities it introduces. We validate Mistrustful P2P through simulation, and demonstrate its feasibility.

Abstract
In IEEE 802.11 based wireless networks adding more access points does not always guarantee an increase of network capacity. In some cases, additional access points may contribute to degrade the aggregated network throughput as more interference is introduced. This paper characterizes the power interference in CSMA/CA based networks consisting of nodes using directional antenna. The severity of the interference is quantized via an improved form of the Attacking Case metric as the original form of this metric was developed for nodes using omnidirectional antenna. The proposed metric is attractive because it considers nodes using directional or omnidirectional antenna, and it enables the quantization of interference in wireless networks using multiple transmission power schemes. The improved Attacking Case metric is useful to study the aggregated throughput of IEEE 802.11 based networks; reducing Attacking Case probably results in an increase of aggregated throughput. This reduction can be implemented using strategies such as directional antenna, transmit power control, or both.

Abstract
INESC TEC is strongly committed to become a center of excellence in maritime technology and, in particular, deep sea technology. The STRONGMAR project aims at creating solid and productive links in the global field of marine science and technology between INESC TEC and established leading research European institutions, capable of enhancing the scientific and technological capacity of INESC TEC and linked institutions, helping raising its staff's research profile and its recognition as a European maritime research center of excellence. The STRONGMAR project seeks complementarity to the TEC4SEA research infrastructure: on the one hand, TEC4SEA promotes the establishment of a unique infrastructure of research and technological development, and on the other, the STRONGMAR project intends to develop the scientific expertise of the research team of INESC TEC.

Abstract
Wireless sensor networks (WSNs) may be made of a large amount of small devices that are able to sense changes in the environment, and communicate these changes throughout the network. An example of a similar network is a photo voltaic (PV) power plant, where there is a sensor connected to each solar panel. The task of each sensor is to sense the output of the panel which is then sent to a central node for processing. As the network grows, it becomes impractical and even impossible to configure all these nodes manually. And so, the use of self-organization and auto-configuration algorithms becomes essential. In this paper, three algorithms are proposed that allow nodes in the network to automatically identify their closest neighbors, relative location in the network, and select which frequency channel to operate in. This is done using the value of the Received Signal Strength Indicator (RSSI) of the messages sent and received during the setup phase. The performance of these algorithms is tested by means of both simulations and testbed experiments. Results show that the error in the performance of the algorithms decreases as we increase the number of RSSI values used for decision making. Additionally, the number of nodes in the network affects the setup error. However, the value of the error is still acceptable even with a high number of nodes.

Abstract
A common problem in networking research and development is the duplicate effort of writing simulation and implementation code of network protocols. This duplication can be avoided through the use of fast prototyping development processes, which enable reusing simulation code in real prototyping and in production environments. Although this functionality is already available by using ns-3 emulation, there are still limitations regarding the additional packet processing that emulation introduces, which degrades the node’s performance and limits the amount of network traffic that can be processed. In this paper we propose an approach to reduce the performance problem associated with fast prototyping that consists in migrating data plane operations processing to outside of ns-3. In a well-designed network, most of the traffic should be data. By moving the data plane operations outside of ns-3 the overhead associated with this kind of traffic is greatly reduced, while control plane protocols may still be reused. In order to validate our proposed solution, we extended the Wireless Metropolitan Routing Protocol (WMRP) and Optimized Link State Routing (OLSR) protocols to use the developed architecture, tested their performance in real environments, and verified the amount of code reuse between the simulator and the real system. © 2016 ACM.