Barry Porter

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In order to provide an increasing number of functionalities and benefit from sophisticated and application-tailored services from the network, distributed applications are led to integrate an ever-widening range of networking technologies. As these applications become more complex, this requirement for 'network heterogeneity' is becoming a crucial issue in(More)
In this paper we examine the current state of the art in WSN operating systems in terms of their general programming models and runtime reprogramming features. While all OSs admit the need -- and provide some capability -- for runtime reprogramming, we find that no existing OS employs a unified approach at the dynamic end of the spectrum. In this paper we(More)
Next-generation Grid applications will be highly heterogeneous in nature, will run on many types of computer and device, will operate within and across many heterogeneous network types, and must be explicitly configurable and runtime reconfigurable. We refer to this future Grid environment as the “divergent Grid”. In this paper, we propose a “deep(More)
Significant progress has been made in the design and development of Grid middleware which, in its present form, is founded on web services technologies. However, we argue that present-day Grid middleware is severely limited in supporting projected nextgeneration applications which will involve pervasive and heterogeneous networked infrastructures, and(More)
Middleware solutions for sensor networks have so far mainly focused on communication abstractions, ad-hoc message routing protocols, and power conservation techniques. We argue that customisation and dynamic reconfiguration of sensor network middleware are additional important dimensions to consider. This paper describes a sensor middleware that can be(More)
Experimentally driven research for wireless sensor networks is invaluable to provide benchmarking and comparison of new ideas. An increasingly common tool in support of this is a testbed composed of real hardware devices which increases the realism of evaluation. However, due to hardware costs the size and heterogeneity of these testbeds is usually limited.(More)
Modular software, in which strongly-separated units of functionality can be independently added to and removed from a node's running software, offers a promising approach to effective dynamic software updating in Wireless Sensor Networks (WSNs). Modular software updating approaches offer high efficiency, in terms of both network costs and update(More)
We present and evaluate a generic approach to the repair of overlay networks which identifies general principles of overlay repair and embodies these as a reusable service. At the heart of our approach is an algorithm that discovers the extent of a failed section of any type of overlay, and assigns responsibility to carry out the repair. The repair strategy(More)
Implementing overlay software is non-trivial and time-consuming. Current projects build overlays or intermediate frameworks on top of low-level networking abstractions. This leads to far reaching incompatibilities between overlay implementations, tight coupling to frameworks and limited adaptability to different deployment environments. We present a new(More)