A DSL Paradigm for Domains of Services: A Study of Communication Services

The domain of services for mobile communication terminals has long become a fast-moving target. Indeed, this domain has been affected by a continuous stream of technological advances on aspects ranging from physical infrastructures to mobile terminals. As a result, services for this domain are known to be very unpredictable and volatile. This situation is even worse when considering services relying heavily on multimedia activities (e.g., games, audio and/or video messages, etc.). Such an application area is very sensitive to a large variety of aspects such as terminal capabilities (graphics, CPU, etc.), bandwidth, service provider's billing policies, QoS, and user expectations. To address these issues, we present a paradigm based on domain-specific languages (DSLs) that enables networking and telecommunication experts to quickly develop robust communication services. Importantly, we propose implementation strategies to enable this paradigm to be supported by existing software infrastructures. Our DSL paradigm is uniformly used to develop a platform for communication services, named Nova. This platform addresses various domains of services including telephony services, e-mail processing, remote- document processing, stream processing, and HTTP resource adaption

Efficient Reliable Real-Time Group Communication for Wireless Local Area Networks

We consider teams of mobile autonomous robot systems that coordinate their work via communication over a wireless local area network. In such a scenario, timely delivery and group support are the predominant requirements on the communication protocol. As the mobile robot systems are communicating via standard hardware, we base our work on the IEEE 802.11 standard for wireless local area networks. In this paper, we present a reliable real-time group communication protocol that enhances the IEEE 802.11 standard. The reliability and real-time properties of the protocol are based on time-bounded dynamic time redundancy. By this, network bandwidth is used much more efficiently than in a message diffusion approach based on static redundancy. The fault detection mechanism needed to implement the time-bounded dynamic redundancy concept is achieved by an implicit acknowledgement scheme that consumes no additional bandwidth for acknowledgement messages. Keywords: mobile computing, wireless loca..