Localisation is required for many ad-hoc sensor network applications. In this paper we look at the limitations of the existing localisation technique, Anchor Free Localisation (AFL) with regards to coping with non-uniform anchor distributions and errors in ranging information. We present a refined approach called Refined Anchor Free Localisation (R-AFL) that uses a combination of mobile anchor ...

Localisation is required for many ad-hoc sensor network applications. Therefore, much work has been done regarding techniques for localisation, mainly using anchors (nodes with known locations). However, there has been little study of how anchors are likely to be distributed in applications, and how to perform localisation with more realistic anchor distributions. In this paper we look at the l...

We present an approach for the localization of passive nodes in a communication network using ambient radio or sound signals. In our settings, the communication nodes have unknown positions. They do not emit signals for localization and exchange only the time points when environmental signals are received: the time differences of arrival (TDOA). The signals occur at distant but unknown position...

This Msc. Thesis builds upon a work-in progress called collocal which researched room-level indoor-localization. Localization is the action of estimating the position of a certain entity on a map. For example tracking the postion of furniture and other inventory in a building over a long period of time. To localize these entities other static nodes are employed that know their own location. The...

As the demand for wireless mobile devices capable of executing real-time applications increases and as the number of mobility users grows, the Mobile IP has necessitated the development of better handoff techniques, for providing seamless handoff, namely, a packet lossless Quality of Service (QoS) guarantee. The Hierarchical Mobile IPv6 (HMIPv6), is to enhance the Mobile IPv6, is designed to re...

The Location-based service on Wireless Sensor Networks, mainly depend on the Receiver Signal Strength (RSS) to measure the distance between the sender and receiver. The location unaware sensor nodes send beacon periodically which captured by anchor sensor nodes. However, the estimated distances may incur large error, and will risk the localization precision. A secant location estimation algorit...

The proliferation of mobile computing devices has enabled the utilization of infrastructureless networking as commercial solutions. However, the distributed and cooperative nature of routing in such networks makes them vulnerable to a variety of attacks. This paper proposes a host-based monitoring mechanism, called SIDE that safeguards the operation of the AODV routing protocol. SIDE encompasse...

An effective approach to dynamic obstacle avoidance for mobile robots is described in this paper. The main concepts in this approach include local Polar Object Chart (POC) for defining possible ways out, obstacle definition, detour mode, anchor for preventing getting lost, steering delimiting and velocity delimiting. The presented concepts and methods were tested and verified both by simulation...

More and more mobile device manufacturers are recognizing the importance of security for their devices in order to protect valuable information of their customers. However, the security of many mobile devices currently does not suffice to protect against modern sophisticated attackers. This paper will go into detail on how these devices can be secured at the hardware level, to ensure that the d...

Hierarchical Mobile IPv6 (HMIPv6) is an enhanced Mobile IPv6 for reducing signaling cost of location management. Multi-level Hierarchical Mobile IPv6 (MHMIPv6) can organize mobile region as a multi-level hierarchy architecture, which is more flexible to support scalable services. However, MHMIPv6 will bring additional packet processing overhead, and produce negative impact especially on some mo...