Due to the inherent nature of their heterogeneity, resource scarcity and dynamism, the provision of middleware for future networked embedded environments is a challenging task. In this paper we present a middleware approach that addresses these key challenges; we also discuss its application in a realistic networked embedded environment. Our application scenario involves fire management in a road tunnel that is instrumented with networked sensor and actuator devices. These devices are able to reconfigure their behaviour and their information dissemination strategies as they become damaged under emergency conditions, and firefighters are able to coordinate their operations and manage sensors and actuators through dynamic reprogramming. Our supporting middleware is based on a two-level architecture: the foundation is a language-independent, component-based programming model that is sufficiently minimal to run on any of the devices typically found in networked embedded environments. Above this is a layer of software components that offer the necessary middleware functionality. Rather than providing a monolithic middleware 'layer', we separate orthogonal areas of middleware functionality into self-contained components that can be selectively and individually deployed according to current resource constraints and application needs. Crucially, the set of such components can be updated at runtime to provide the basis of a highly dynamic and reconfigurable system.

At present, military communications within battlefields are very restricted, both by policy and due to technology limitations. In Southwest Asia today, there are needlessly long and complex communications paths, often involving multiple relays and use of constrained-bandwidth MILSATCOM back-haul outside the theatre, when nearby forces could communicate directly via existing interoperable radios. This is a current problem for NATO and Coalition forces. The current Internet Protocol suite lacks core support for mobility, scalable support for multi-homed nodes, and does not provide the capabilities needed for optimal communications in forward operating areas. We propose a coalition-based, multi-homed approach leveraging both local-area and wide-area connectivity, improving both the flexibility and robustness of communication, without conflicting with the security policy of sensitive communication. The Coalition Peering Domain (CPD), is a distributed, self-configuring architecture that supports the secure, collaborative networking relationships needed to provide this flexibility and robustness. The CPD facilitates the inter-connection of cooperating, but administratively separate, network segments. The CPD exploits multi-homed and multi-path communication to better-utilise all available connectivity. The Identifier-Locator Network Protocol (ILNP) provides native support for improved scalability in multi-homing and mobility, while easing use of network layer security and allowing inter-operation across different administrative domains. Our approach is compatible with current work in Mobile Ad-Hoc Networking (MANET). ILNP has excellent compatibility with IPv6: existing IPv6 backbone networks do not require any modification to carry ILNP traffic natively. There are practical, realistic and deployable engineering solutions to realise the CPD and ILNP within the framework of IPv6.

Mesh networking has recently received considerable attention, largely as a mechanism for providing enhanced connectivity without the need to install additional expensive infrastructure. It relies on the fact that underutilised local area connectivity can be used to connect constrained devices to those that possess wide-area uplink capabilities. However, at present, proposals for uplink bandwidth sharing are limited by the use of a traditional view of routing in which multiple end-user devices are associated with each individual uplink in such a way that all their off-network traffic is routed through that particular gateway. While this has the merit of simplicity, it is possible for a subset of gateways to be overloaded while others remain underutilised. We propose a new type of local mesh network, called the Coalition Peering Domain, the goal of which is to maximise Internet connectivity dynamically, smoothing out the usage of uplink capacity, albeit at the cost of slightly more complex control and management. Within this paper, we describe three main routing and addressing issues and then propose novel mechanisms that partially address those issues.

Abstract-Next generation embedded systems will be composed of large numbers of heterogeneous devices. These will typically be resource-constrained (such as sensor motes), will use different operating systems, and will be connected through different types of network interfaces. Additionally, they may be mobile and/or form ad-hoc networks with their peers, and will need to be adaptive to changing conditions based on context-awareness.As an example of these system we consider disaster recovery scenarios where large numbers of different devices need to interconnect in an ad-hoc manner. In this respect, our goal is the provisioning of a middleware framework for such system environments. Our approach is based on a small and efficient middleware kernel supporting highly modularised and customisable component-based middleware services. These services can be tailored for specific embedded environments, and are runtime-reconfigurable to support adaptivity. This paper describes a demonstration that highlights some of the features available in our middleware. In particular, we focus on heterogeneity handling by showing our middleware running on resource-rich as well as resource-constrained devices, and on adaptivity features by demonstrating runtime reprogramming and on-the-fly component deployment.

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