Developments in mobile devices and wireless networking provide the technical platform for video streaming over mobile ad hoc networks (MANETs). However, efforts to realize video streaming over MANETs have met many challenges, which are addressed by several different techniques. Examples include cross-layer optimization, caching and replication, and packet prioritization. Cross-layer optimization typically leverages multiple description video coding and multipath routing to provide the receiver(s) sufficient video quality. Caching and replication add tolerance to disruptions and partitioning. In this paper, we identify the challenges of realizing video streaming over MANETs, and analyze and classify the proposed techniques. Since 65 % of the identified involve cross-layering design, we study the distribution of joint optimization and parameter exchanges. Due to the importance and complexity of evaluating the techniques, we analyze the common methods, indicating that the research domain suffers from a problem of comparability.

Due to the technical developments in electronics the amount of digital content is continuously increasing. In order to make digital content respectively multimedia content available to potentially large and geographically distributed consumer populations, Content Distribution Networks (CDNs) are used. The main task of current CDNs is the efficient delivery and increased availability of content to the consumer. This area has been subject to research for several years. Modern CDN solutions aim to additionally automate the CDN management. Furthermore, modern applications do not just perform retrieval or access operations on content, but also create content, modify content, actively place content at appropriate locations of the infrastructure, etc. If these operations are also supported by the distribution infrastructure, we call the infrastructure Content Networks (CN) instead of CDN. In order to solve the major challenges of future CNs, researchers from different communities have to collaborate, based on a common terminology. It is the aim of this paper, to contribute to such a terminology, to summarize the state-of-the-art, and to highlight and discuss some grand challenges for CNs that we have identified. Our conception of these challenges is supported by the answers to a questionnaire we received from many leading European research groups in the field. q

Development of applications and protocols for mobile ad-hoc networks has always been a challenge. Specific characteristics such as frequent topology changes due to nodes moving around, popping up or being turned off, need to be considered from the earliest stages of development. Since testing and evaluation using genuine wireless devices is both expensive and highly impractical, other tools need to be used in the development phase. Simulators give a very detailed model of lower layers' behaviors, but code often needs to be completely rewritten in order to be used on actual physical devices. Emulators present a trade-off between real test beds and simulators, providing a virtual wireless network at the lowest layers, and yet allowing real code to be run on the higher layers. In this paper, we present such an emulation platform, called NEMAN, that allows us to run a virtual wireless network of hundreds of nodes on a single end-user machine. NEMAN has shown to be an important and very useful tool during development of different applications and protocols for our project, including a key management protocol and a distributed event notification service.

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Because of an elevated serum phosphate level, patients who suffer from chronic kidney failure frequently tend to have cardiovascular calcification and are therefore exposed to a higher probability of a fatal event. Phosphate binders are able to reduce these negative effects. Currently, there are primarily two groups of phosphate binders (calcium-containing and calcium-free phosphate binders) which are considered to be almost equally effective in terms of binding of free phosphate. There are, however, a few disadvantages of the two groups. While the calcium-containing binders are associated with an increased risk of hypercalcemia, which is dose dependent, calcium-free binders have been criticized as being too expensive. As the expenditure for patients suffering from chronic kidney failure increases from year to year, as a result of increasing prevalence, there is a growing need for an alternative to existing phosphate binders. The study presented here therefore summarizes available information for the novel combination preparation OsvaRen® (calcium acetate/magnesium carbonate) as an alternative therapy to the calcium-free phosphate binder Renagel® (sevelamer-hydrochloride) and to calcium-containing preparations.The results of this systematic review showed that OsvaRen® is at least equally effective in the regulation of serum phosphate level as Renagel®. In particular, OsvaRen® shows no clinically relevant difference in terms of the control of the serum calcium levels compared to Renagel® and thereby does not increase the risk of a hypercalcaemia, in contrast to pure calcium-based phosphate binders. On the other hand, Renagel® therapy is much more frequently associated with gastrointestinal side-effects, a tendency to result in higher tablet burden for patients and high medication costs. The CALMAG study showed that OsvaRen® was at least as effective and safe in terms of controlling serum phosphate and serum calcium levels as Renagel® while, at the same time, resulting in about 80% lower costs. In addition, OsvaRen® offers a lower risk of hypercalcaemia and associated subsequent costs and is thereby also superior to pure calcium-containing phosphate binders.Because of the effectiveness and tolerability of calcium acetate/magnesium carbonate, OsvaRen® offers a clinically suitable and, at the same time, cost-effective therapeutic option in the therapy of hyperphosphataemia.