J. Sa Silva

Why is IPSec a viable option for wireless sensor networks

Many issues still remain to be addressed in order to achieve acceptable security in wireless sensor networks (WSNs). This necessity, together with the adoption of IPv6 on WSNs being defined at the 6lowpan working group of the IETF, motivates our investigation on the feasibility of the application of IPSec on sensor nodes. IPSec is already part of IPv6, which makes it a natural candidate to be directly employed or adapted for WSNs. We discuss results obtained from practical experiments on the usage of cryptographic algorithms typically employed within IPSec in real sensor nodes. We analyze the security and performance tradeoffs involved when employing cryptography measures in WSNs, also in the context of their usage side-by-side with IPv6. The results obtained show that the adoption of a security architecture such as IPSec is viable, and also point towards the successful design and deployment of a security architecture for WSNs.

Mobility management in IP-based Wireless Sensor Networks

Mobility is one of the most important issues in next generation networks. As wireless sensor networks are becoming the next elements of the future Internet, it is crucial to study new models that also support mobility of these nodes. This paper presents and studies three paradigms to support mobility in sensor nodes. This study is supported by prototyping. As a result a set of proposals are proposed and discussed. The work presented in this paper proposes the use of IP in wireless sensor networks as a unifying protocol and it is in compliance with the IETF 6LowPAN group.

6GLAD: IPv6 Global to Link-layer ADdress Translation for 6LoWPAN Overhead Reducing

The next generation of wireless sensor networks will integrate communication systems beyond the third generation paradigm. As a result of this integration, the new communication systems will be fed by the sensor networks with information gathered from the environment, achieving context awareness. To reach the necessary end-to-end connectivity between all-IP networks and sensor networks, the IETF 6LoWPAN working group has designed an IPv6 adaptation layer for low power devices. This protocol stack provides IPv6 interoperability to the sensor networks, thus avoiding as much overhead as possible. This paper analyses and evaluates the associated IP communication overhead in each possible 6LoWPAN scenario, from intra to inter network communication. We conclude that, even the 6LoWPAN offering a light weight IP solution for link local sensor network communication, it has a relatively high overhead when data flows between different networks. In order to avoid the communication overhead when global IPv6 addressing is necessary we propose a new solution based on a 6LoWPAN global-to-link-layer address translation.

Performance control in wireless sensor networks: the ginseng project - [Global communications news letter]

Research on wireless sensor networks (WSNs) has mainly been focused on protocols and architectures for applications in which network performance assurances are not considered essential, such as agriculture and environmental monitoring. However, for many important areas, such as plant automation and health monitoring, performance assurances are crucial, especially for metrics such as delay and reliability.

IP in wireless sensor networks Issues and lessons learnt

This paper addresses the issue of IP in wireless sensor networks, comparing the use of IPv4 and IPv6. Although a considerable number of studies on wireless sensor networks exist, most of them are based on simulation only. This is not the case of the current paper. In order to validate and complement the simulation studies, this paper presents the construction, deployment and evaluation of a real testbed for the study of IP in Wireless Sensor Networks. The testbed is based on Contiki over embedded sensor boards nodes. The results show that the impact of IPv6 is negligible when compared with IPv4, and that IPv6 may even be beneficial due to its higher functionality and to the simpler composition of its headers.

WSN evaluation in industrial environments first results and lessons learned

The GINSENG project develops performance-controlled wireless sensor networks that can be used for time-critical applications in hostile environments such as industrial plant automation and control. GINSENG aims at integrating wireless sensor networks with existing enterprise resource management solutions using a middleware. A cornerstone is the evaluation in a challenging industrial environment — an oil refinery in Portugal. In this paper we first present our testbed. Then we introduce our solution to access, debug and flash the sensor nodes remotely from an operations room in the plant or from any location with internet access. We further present our experimental methodology and show some exemplary results from the refinery testbed.

Multicast in Wireless Sensor Networks The next step

Multicast potentially optimises bandwidth consumption and node resources, when several users simultaneously participate in a communication session. Nevertheless, contrary to the expectations, IP multicast has not experienced widespread deployment, with the exception of IPTV. On the other hand, emerging wireless sensor network (WSN) applications could greatly benefit from multicast and constitute another field where multicast can be an effective and efficient technique. The question is: do multicast advantages hold in WSN scenarios? This paper discusses and evaluates the use of multicast in wireless sensor networks. A WSN platform with IP support and multicast is being developed. Concurrently, simulation studies were performed in order to assess the usefulness of multicast in WSNs. The results clearly point to the benefits of the use of this technique in processing and energy-restricted environments such as this one

Designing the simulative evaluation of an architecture for supporting QoS on a large scale

The EuQoS system is a complete QoS system, scalable to large dimensions and addressing QoS at all relevant layers, which has been developed within the framework of the IST-EuQoS project. Its design has been aided by a considerable amount of modeling and simulation work, aimed at testing the various QoS mechanisms devised and their interaction. This paper describes the modeling and simulation work done in the framework of the project. We describe the three simulation models which have been developed, based on the different timescales at which the QoS mechanisms have effect. Furthermore, as a sample case of performance evaluation, involving different simulators, we describe the performance evaluation of the EuQoS signaling subsystem.

NSIS-based quality of service and resource allocation in ethernet networks

The definition of the IEEE 802.1Q and IEEE 802.1p standards provided Class of Service (CoS) capabilities to Ethernet networks and, consequently, allowed new QoS services to be deployed. This is used by the Subnet Bandwidth Management (SBM) protocol, an RSVP-based protocol that provides IntServ-like services at Ethernet level. This paper proposes an alternative way to quality of service provision and resource allocation in Ethernet networks, based on the emerging IETF NSIS framework. The proposed approach was validated as a proof of concept by simulation, showing the ability of NSIS to provide QoS differentiation in Ethernet scenarios.

Percontrol: A pervasive system for educational environments

This paper presents the development of a control system for learning environments specialized in special education. Amongst its various possible uses, the system focuses on managing the class attendance of special education students, teachers and other classroom users through the use of pervasive and ubiquitous technologies. For developing tests and obtaining results, electronic devices that monitor and control the environment were used, in particular, SunSpot devices. These nodes detect and store environmental data in an omnipresent distributed database. Another contribution present in this work is the use of a hybrid middleware for controlling the application and the devices used in these environments.