Fly-By-Wireless for Next Generation Aircraft: Challenges and Potential solutions

”Fly-By-Wireless” paradigm based on wireless connectivity in aircraft has the potential to improve efficiency and flexibility, while reducing weight, fuel consumption and maintenance costs. In this paper, first, the opportunities and challenges for wireless technologies in safety-critical avionics context are discussed. Then, the assessment of such technologies versus avionics requirements is provided in order to select the most appropriate one for a wireless aircraft application. As a result, the design of a Wireless Avionics Network based on Ultra WideBand technology is investigated, considering the issues of determinism, reliability and security

A load-balanced complete-exchange multicast protocol for wireless Ad-Hoc networks

[[abstract]]Complete-exchange multicasting is quite useful for numerous applications. We explicate a load-balanced complete-exchange multicast protocol (LCM), based on passive clustering, for wireless ad-hoc networks. From a logical viewpoint, LCM constructs multiple cluster structures to balance the traffic loads among all group members. It further avoids overloading of nodes or traffic congestion on the route. In LCM, an innovative scheme is devised to deal with the scenario in which a node plays different roles for different cluster structures. Simulation results show that LCM not only preserves all the advantages of passive clustering, but also performs very efficiently in complete-exchange multicasting. Consequently, LCM is really a feasible solution for load-balanced complete-exchange multicasting, especially for dense networks.[[conferencetype]]國際[[conferencedate]]20040627~20040629[[booktype]]紙本[[conferencelocation]]Chengdu, Chin

A performance study of routing protocols for mobile grid environment

Integration of mobile wireless consumer devices into the Grid initially seems unlikely due to limitation such as CPU performance,small secondary storage, heightened battery consumption sensitivity and unreliable low-bandwidth communication. The current grid architecture and algorithm also do not take into account the mobile computing environment since mobile devices have not been seriously considered as valid computing resources or interfaces in grid communities. This paper presents the results of simulation done in identifying a suitable ad hoc routing protocol that can be used for the target grid application in mobile environment. The simulation comparing three ad hoc routing protocols named DSDV, DSR and AODV

Robust streaming in delay tolerant networks

Delay Tolerant Networks (DTN) do not provide any end to end connectivity guarantee. Thus, transporting data over such networks is a tough challenge as most of Internet applications assume a form of persistent end to end connection. While research in DTN has mainly addressed the problem of routing in various mobility contexts with the aim to improve bundle delay delivery and data delivery ratio, little attention has been paid to applications. This paper investigates the support of streaming-like applications over DTN. We identify how DTN characteristics impact on the overall performances of these applications and present Tetrys, a transport layer mechanism, which enables robust streaming over DTN. Tetrys is based on an on the fly coding mechanism able to ensure full reliability without retransmission and fast in-order bundle delivery in comparison to classical erasure coding schemes. We evaluate our Tetrys prototype on real DTN connectivity traces captured from the Rollerblading tour in Paris. Simulations show that on average, Tetrys clearly outperforms all other reliability schemes in terms of bundles delivery service

Novel multicast protocols in ad-hoc networks

Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

A survey of handover algorithms in DVB-H

Digital Video Broadcasting for Handhelds (DVB-H) is a standard for broadcasting IP Datacast (IPDC) services to mobile handheld terminals. Based on the DVB-T standard, DVB-H adds new features such as time slicing, MPE-FEC, in-depth interleavers, mandatory cell id identifier, optional 4K-modulation mode and the use of 5 MHz bandwidth in addition to the usually used 6, 7, or 8 MHz raster. IPDC over DVB-H is proposed for ETSI to complement the DVB-H standard by combining IPDC and DVB-H in an end-to-end system. Handover in such unidirectional broadcasting networks is a novel issue. In the last few years since the birth of DVB-H technology, great attention has been given to the performance analysis of DVB-H mobile terminals. Handover is one of the main research topics for DVB-H in mobile scenarios. Better reception quality and greater power efficiency are considered to be the main targets of handover research for DVB-H. New algorithms for different handover stages in DVB-H have been the subject of recent research and are currently being studied. Further novel algorithms need to be designed to improve the mobile reception quality. This article provides a comprehensive survey of the handover algorithms in DVB-H. A systematic evaluation and categorization approach is proposed based on the problems the algorithms solve and the handover stages being focused on. Criteria are proposed and analyzed to facilitate designing better handover algorithms for DVB-H that have been identified from the research conducted by the author

Adapting SLP to ad-hoc environment

Ad-hoc networking, where network structure is created dynamically as nodes enter and leave the network, has recently become an active reseach subject. As majority of existing network protocols has been targeted to be used in an environment, where a static network configuration and the option of using registry repositories is enabled, they need tailoring for ad-hoc networking. In this paper, we discuss how Service Location Protocol (SLP) can be modified for such a dynamic environment starting from the requirements of applications that are to be run, and user’s intentions. The adaptations we have implemented include passive service discovery where the amount of network traffic needed for service discovery can be reduced, security related features for improved privacy, gateway function that offers connectivity to external networks, and service discovery proxies that assist in the discovery of services between ad-hoc and fixed networks. The paper also addresses implementation of these features.1st IFIP International Conference on Ad-Hoc NetWorkingRed de Universidades con Carreras en Informática (RedUNCI