Fariaz Karim

Reconfigurable context-sensitive middleware for pervasive computing

Context-sensitive applications need data from sensors, devices, and user actions, and might need ad hoc communication support to dynamically discover new devices and engage in spontaneous information exchange. Reconfigurable Context-Sensitive Middleware facilitates the development and runtime operations of context-sensitive pervasive computing software.

An Adaptive Middleware for Context-Sensitive Communications for Real-Time Applications in Ubiquitous Computing Environments

Context-sensitivity is an important expected capability in applications in ubiquitous computing (ubicomp) environments. These applications need to use different contextual information from the user, host device, on board sensors, network, and the ambient environments to systematically adapt their actions. In addition, some context-sensitive applications may use specific contextual conditions to trigger impromptu and possibly short-lived interactions with applications in other devices. This property, referred to as context-sensitive or context-aware communications, allows applications to form short-range mobile ad hoc networks consisting of mobile and stationary devices, sensors, and other computing resources. Real-time applications, especially those having reactive behavior, running on embedded devices and requiring context-sensitive communications support, pose new challenges related to systematic representation of specific contexts, associations of contexts with real-time actions, timely context data collection and propagation, and transparent context-sensitive connection establishment. An object-based middleware can be effective to meet these challenges if such a middleware can provide a well-defined development framework as well as lightweight runtime services. In this paper, an adaptive and object-based middleware, called reconfigurable context-sensitive middleware (RCSM) is presented to facilitate context-sensitive communications in ubicomp environments. To facilitates context-sensitive communications, RCSM provides a context-aware interface definition language for specifying context-sensitive interfaces of real-time objects, an object container framework for generating interfaces-specific context-analyzers, and a context-sensitive object request broker for context-sensitive object discovery and impromptu connection management. RCSM is adaptive in the sense that depending on the context-sensitive behavior of the applications, it adapts its object discovery and connection management mechanisms.

Context-sensitive middleware for real-time software in ubiquitous computing environments

Context-awareness is increasingly becoming an important capability in devices for ubiquitous computing environments. These devices use on-board sensors and history of user interaction to collect data that are used to adapt their behavior to suit with the current environment. There is a need to support real-time software in ubiquitous computing environments, especially in reactive systems, such as distributed and mobile sensors, location-based information services, etc. In these cases, both behavior and the interaction among devices depend on constantly changing environmental conditions, in addition to explicit user control. This characteristic requires specific system services to support the development and the runtime operation of real-time context-aware software. This implies that the underlying services must themselves be context-sensitive. Reconfigurable context-sensitive middleware (RCSM) is presented to facilitate real-time context-aware software in ubiquitous computing environments.

A context-sensitive middleware for dynamic integration of mobile devices with network infrastructures

Network infrastructures (NI), such as the Internet, grid, smart spaces, and enterprise computing environments usually consists of computing nodes that are stationary, provide the backbone for environment sensing and high-performance computing and communication. NI, in addition, may have various types of application software for performing resource-intensive computation. On the other hand, recent advances in the embedded systems and wireless communication technologies have increased the flexibility of using mobile devices for various practical applications. Mobile devices mostly execute application software that improves the personal productivity of the user. However, despite the rapid technology advances, mobile devices are expected to be always resource poor in comparison with the computing resources in the NIs. On the other hand, the computing resources in an NI cannot readily add the flexibility to individual users due to their fixed location and size. It is therefore desirable to combine the respective strengths of mobile devices and network infrastructures (NI) whenever possible. Dynamic integration is the process using which a mobile device can detect, communicate with, and use the required resources in nearby NIs in an application-transparent way. The benefit of dynamic integration is that the applications in both mobile device and NI can interoperate with each other as if a mobile device itself is an integral part of the NI or vice versa. In this paper, a context-sensitive middleware, called Reconfigurable Context-Sensitive Middleware (RCSM), is presented for addressing this dynamic integration problem. A novel feature of RCSM is that its dynamic integration mechanism is context-sensitive, and as such the integration between the application software in a mobile device and an NI can be restricted to specific contexts, such as a particular location or a particular time. RCSM, furthermore, provides transparency over the dynamic resource discovery and networking aspects so that application-level cohesion can be easily achieved. The integration process does not force any development-time restrictions on the application software in an NI. Our experimental results, based on the implementation of RCSM in integrated ad hoc and infrastructure-based IEEE 802.11 test bed environment, indicate that the integration process is lightweight and results in reasonably high performance in PDA-like devices and desktop PCs.

Adaptive Middleware for Ubiquitous Computing Environments

Rapid growth in inexpensive, short range, and low-power wireless communication hardware and network standards are now enabling the construction of ubiquitous computing and communication environments. Devices in ubicomp environments form short range and low power mobile ad hoc networks whose topologies are usually dynamic due to arbitrary node mobility. Typical applications in ubicomp environments are context-sensitive, adaptive, and often engage in impromptu, and volatile communication. These properties require both programming and runtime support in the application and system levels. A middleware approach can be very effective to provide these support to reduce the effort required to develop ubicomp software, in addition to providing the commonly known middleware services, such as interoperability, location transparency, naming service, etc. In contrast to middleware architectures for fixed networks, a middleware for ubicomp environments should be adaptive to various contexts, be reconfigurable, and should be of high-performance to facilitate ad hoc communication among objects. In this paper, an adaptive middleware, which is reconfigurable and context sensitive, is presented for applications in ubiquitous computing environments.

Reconfigurable context-sensitive middleware for ADS applications in mobile ad hoc network environments

The emergence of inexpensive and low-power wireless communication hardware and various handheld, wearable, and embedded computing technologies is making computing and communication devices more mobile and ubiquitous. Due to the mobility and high-density of network-enabled devices, short range mobile ad hoc networks (MANET) are instantaneously and autonomously formed to facilitate exchange of information. In MANET, interactions among the devices are driven by constantly changing contextual and environmental conditions, rather than by the applications resident on the devices. This trend makes autonomous decentralized systems (ADS) a desirable architecture for facilitating ad hoc communication among mobile devices. In this paper, reconfigurable context-sensitive middleware (RCSM) is presented to facilitate ADS applications in MANET.

Component customization for object-oriented distributed real-time software development

To apply the component-based approach to distributed real-time software development, it is necessary to identify components based on both functional and real-time requirements. Since a component may be acquired from external sources, it becomes necessary during integration to ensure that a component satisfies the real-time requirements of the target application software. Since these requirements vary, customizable so that during integration it can adapt itself to the specific real-time requirements of the target-distributed software. To facilitate such activities, it is preferable to have components that are capable of performing self-customization using a set of built-in services. In this paper, an object-oriented real-time component framework and two built-in customization services are presented to address the specified issues.

Context-sensitive distributed software development for ubiquitous computing environments

Ubiquitous computing represents the next wave of distributed computing, which focus on integrating computers with various wearable, mobile, and sensor devices, thus making computing and communication essentially transparent to the users. This type of environments mainly consists of myriad of embedded computing nodes interacting in transparent fashion to provide different services to the users. In addition to being resource-constrained, applications in these environments are context-sensitive and often operate in mobile ad hoc networks. Although different types of context-sensitive applications with diverse focus have been developed for ubiquitous computing environments, no general methods are available for developing application software for the above environments. In this paper, the development of context-sensitive distributed software for ubiquitous computing environments is presented.

A lightweight middleware protocol for ad hoc distributed object computing in ubiquitous computing environments

Devices in ubiquitous computing environments are usually embedded, wearable, and handheld, have resource constraints, and are all connected to each other through wireless connections and other computers possibly through fixed network infrastructures, such as the Internet. These devices may form numerous webs of short-range and often low-power mobile ad hoc networks to exchange information. Distributed object computing (DOC) middleware technologies have been successful in promoting high quality and reusable distributed software for enterprise-oriented environments. In order to reap the same benefit in ubiquitous computing environments, it is important to note that the natural interactions among distributed objects in ubiquitous computing environments are quite different due to various factors, such as bandwidth constraints, unpredictable device mobility, network topology change, and context-sensitivity (or situation-awareness) of application objects. Hence, the interactions among distributed objects tend to be more spontaneous and short-lived rather than predictable and long-term. In this paper, a middleware protocol, RKF, to facilitate distributed object-based application software to interact in an ad hoc fashion in ubiquitous computing environments is presented. RKF addresses both spontaneous object discovery and context-sensitive object data exchange. Our experimental results, based on RKFs implementation and evaluation inside the object request broker of our RCSM middleware test bed, indicate that it is lightweight, has good performance, and can be easily used in PDA-like devices.

Integration of object-oriented software components for distributed application software development

The process of component integration for distributed application software development requires identifying the candidate components and performing compatibility checks based on the functional as well as non-functional requirements of the target application software. Since these requirements vary, it is important that distributed components themselves provide a set of specific services to facilitate component integration. In this paper, an approach to component integration for distributed application software is given. An object-oriented distributed component framework and a distributed connector model are presented to facilitate component integration.