Abstract
We propose a schedulability analysis for a particular class of time division multiple access (TDAM) networks, which we label as TDAM/SS. SS stands for slot skipping, reflecting the fact that a slot is skipped whenever it is not used Hence, the next slot can start earlier in benefit of hard real-time traffic. In the proposed schedulability analysis, we assume knowledge of all message streams in the system, and that each node schedules messages in its output queue according to a rate monotonic policy (as an example). We present the analysis in two steps. Firstly, we address the case where a node is only permitted to transmit a maximum of one message per TDMA cycle. Secondly we generalise the analysis to the case where a node is assigned a budget of messages per TDMA cycle it may transmit. A simple algorithm to assign budgets to nodes is also presented.

Abstract
Computational methods have been used with great application to biomedical optics. The events created by the interaction of radiation with biological materials can easily be translated to computer languages with the objective of producing simulation techniques to be used prior to physical intervention. The addition of biocompatible and hyper osmotic agents to several types of biological tissues has proven the enhancement of transparency to radiation flux by reduction of material's optical properties. The evolutionary behavior of the agent's action in the tissue samples before saturation has been observed by numerous researchers but has never been described mathematically. In the present work we will describe the application of Monte Carlo simulation to estimate the evolutionary states of optical transparency of biological tissues when immersed in an osmotic solution. We begin our study with typical values for the optical properties of rabbit muscle and proceed by reducing the absorption and scattering coefficients independently and simultaneously. The results show the number of transmitted, absorbed, scattered and reflected photons in different stages of the action of a generic osmotic agent over a small and well defined tissue sample.

Abstract
ReDiFlex is a system that supports the development of applications that use dynamically and partially-reconfigurable hardware. The hardware functionality is specified by the flow of data between mutable operators. The system automatically creates the physical implementation after partitioning the model to fit the hardware constraints; during application execution new computation-dependent partial configurations can be created. ReDiFlex provides run-time support for reconfiguration and data transfer scheduling.

Abstract
Applications and products currently available for the broadcasting market are vertically integrated or proprietary They are based on components requiring specific and costly development to interoperate and typically rely on a single manufacturer or system integrator Hence, they are not fully compliant with broadcasters' requirements. Architectural Solutions for Services Enhancing digital Television (ASSET) is a European-funded project. Its main goal is to overcome the limitations of custom-specific implementations in a digital system for TV content creation. These limitations are generally due to the misfit of interfaces between software layers, proprietary application program interfaces (APIs) of equipment from different vendors, and the lack of a generalized middleware for multimedia content management with openly defined interfaces. Besides presenting the ASSET-proposed architecture and concepts, this paper describes the prototype under development to test and demonstrate the project proposals.

Abstract
The classical TCP/IP layered protocol architecture is beginning to show signs of age. In order to cope with problems such as the poor performance of wireless links and mobile terminals, including the high error rate of wireless network interfaces, power saving requirements, quality of service, and an increasingly dynamic network environment, a protocol architecture that considers cross-layer interactions seems to be required. This article describes a framework for further enhancements of the traditional IP-based protocol stack to meet current and future requirements. Known problems associated with the strictly layered protocol architecture are summarized and classified, and a first, solution involving cross-layer design is proposed.

Abstract
This paper focuses on improved error control schemes for highspeed wireless digital communications. The main objective is a better quality support for real-time services, such as video, when using wireless mobile digital networks. In view of that, and besides the schemes already standardized, a novel error control mechanism is proposed. This new mechanism relies mainly in the use of Hybrid Automatic Repeat reQuest (HARQ) error control schemes and differentiated error robustness transmission modes. In this sense, when implementing this new technique, some of the capabilities offered by modem Wireless Local Area Networks (WLANs) are significantly better utilized. To make the performance analysis of the proposed error control mechanism, and corresponding comparison with existing systems, it was developed a system simulation environment, together with other computational tools. Analysis for diverse radio channel conditions, from AWGN modeling to Gilbert-Elliot modeling, has been done and some examples are subsequently presented. The simulation results show that this new strategy greatly improves the performance of real-time services, fulfilling the requirement of limited delays and enabling higher data rates.