Peter De Cleyn

A Secure Cross-Layer Protocol for Multi-hop Wireless Body Area Networks

The development of Wireless Body Area Networks (WBANs) for wireless sensing and monitoring of a persons vital functions, is an enabler in providing better personal health care whilst enhancing the quality of life. A critical factor in the acceptance of WBANs is providing appropriate security and privacy protection of the wireless communication. This paper first describes a general health care platform and pinpoints the security challenges and requirements. Further it proposes and analyzes the CICADA-S protocol, a secure cross-layer protocol for WBANs. It is an extension of CICADA, which is a cross-layer protocol that handles both medium access and the routing of data in WBANs. The CICADA-S protocol is the first integrated solution that copes with threats that occur in this mobile medical monitoring scenario. It is shown that the integration of key management and secure, privacy preserving communication techniques within the CICADA-S protocol has low impact on the power consumption and throughput.

Performance Analysis of IP Micro-mobility Handoff Protocols

Micro-mobility protocols have been proposed to provide seamless local mobility support. This paper focuses on the performance of the handoff schemes of two candidates for micro-mobility protocols, namely HAWAII and Cellular IP. For each handoff scheme, a simple analytical model is developed for the evaluation of two characteristic performance measures: the packet loss probability during handoff and the extra delay experienced by packets that are involved in the handoff. Application of these models allows a comparison of two important handoff schemes: the Multiple Stream Forwarding scheme of HAWAII and the Semi-soft Handoff scheme of Cellular IP.

A smooth handoff scheme using IEEE802.11 triggers: design and implementation

This paper proposes a handoff scheme in a wireless access network where IEEE802.11 is used as link layer protocol and Mobile IP as network layer protocol. The scheme uses triggers available from IEEE802.11, together with packet buffering in the old Access Point and packet forwarding from the old to the new Access Point in order to provide a smooth handoff. The proposed scheme has been implemented on a Linux based testbed and it has been analysed by means of an ns simulation and an analytical model. The paper reports on the results obtained from the testbed, the simulation and the analytical model, both for constant bit rate traffic (in particular streamed RTP video) and TCP traffic.

Supporting Mobility in Body Sensor Networks

Body Sensor Networks (BSNs) form a promising technology to supply healthcare to an ageing population. A large number of sensor devices, radios and MAC protocols are being developed. However, current solutions all assume a single-hop topology, while research results confirm the need for multi-hop topologies. In these multi-hop networks, because of the small scale of a BSN, node mobility will arise frequently. This work presents the first algorithm to support such Mobile BSNs, while remaining energy efficient.

Models for Wireless Data Communications in Indoor Train Environment

The provisioning of wireless data services in the railway environment will become increasingly important for train operators and train constructors in the upcoming years. In this paper, we present models to predict train-to-wayside wireless data communications characteristics in terms of throughput, jitter, and packet loss predictions for 2G/3G networks. To this end, an extensive measurement campaign is carried out along a Belgian Intercity railway track. Based on these measurements, we apply a multiple regression, window mean, and autoregressive model. We find that the window mean model is recommended for the prediction of throughput and jitter, while the multiple regression model is more favorable for the prediction of packet loss. The implementation of these predictions in train-to-wayside communication systems can enhance the provisioning of seamless network connection necessary for a wide variety of data services.

Node mobility support in body sensor networks

Body Sensor Networks (BSNs) form a promising technology to supply healthcare to an ageing population. Current solutions all assume single-hop networks, while research indicates the need for support of multi-hop topologies. A small movement in a network with small radio ranges, causes frequent node mobility. This work presents the first three algorithms to support Mobile BSNs. It is shown that the algorithms support mobility while being energy efficient.

Wireless Sensor Network interconnection protocol

Wireless Sensor Networks (WSNs) are at high speed gaining in popularity. Because of this increased adoption, the need for integration with existing technologies becomes more prominent. In practice, a WSN is often deployed in environments where both wired and wireless data networks are also present. Consider for instance a WSN which acts as a climate monitoring or fire detection system in a large office building. As WSNs are typically networks with high constraints regarding resource efficiency, it would be beneficial if they could use the available data networks as additional transport medium for their internal data. In this paper we describe an interconnection protocol and associated sensor gateway design which enables the transparent use of both wired and wireless data networks by WSNs. Through this setup, the WSN will detect the non-sensor devices as virtual sensor nodes and consider them when determining the optimal routing paths.

TinySPOTComm: Facilitating Communication over IEEE 802.15.4 between Sun SPOTs and TinyOS-Based Motes

The increasing popularity of sensor network has spawned a wide range of platforms and frameworks for sensor network development. While in theory nodes based on different frameworks should provide radio stack compatibility, in practice this is rarely the case. We explore this problem by providing a case study and introduce TinySPOTComm, a customized radio stack for the Sun SPOT platform which allows for radio communication between IEEE 802.15.4 based TinyOS motes and Sun SPOTs. The TinySPOTComm radio stack remains fully compatible with the Sun SPOT radio stack and its network performance is only marginally affected in comparison to the default Sun SPOT radio stack. Performance tests have shown good results when communicating between TinyOS motes and Sun SPOTs. The round trip time, when measured between a Sun SPOT and a TinyOS mote, is affected by no more than 15%, in comparison to the RTT between two TinyOS motes. In the same scenario an increase in throughput of more than 50% has been measured.