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The availability of multiple technologies to access the Internet is even more common in today's connectivity scenarios. As an example, smartphones make use of 3G/4G data technology but, when a Wi‐Fi access point is available, they switch from 3G/4G (which typically is a paid per volume service) to the wireless local access. The same principle is applicable for fixed access, when terrestrial ADSL or...
TCP Wave is an innovative transport protocol adopting a burst-based transmission approach, instead of the traditional window-based one. In TCP Wave the underlying IP packet transmission process results completely changed because of an internal timer to schedule bursts, which replaces the ACK-clocked transmission of all TCP versions. So far, TCP Wave capabilities have been assessed in a large gamut...
In case of an emergency event (e.g., earthquake, storm, flood) cultural heritage and archeological monuments must be particularly cared because of their inestimable value and the intrinsic greater fragility. Morphological surveys must be executed immediately for quick identification of damages so that the needed operations can be planned and performed in the shortest timeframe. The survey, to be accurate...
After a shipwreck people wear life vest and the available telecommunication systems for rescue operations offer, in the best case, just approximate localization of relicts or lifeboats. A communication system tailored to provide a reliable and real time updated map of positions and health conditions of floating people can improve efficiency of rescue operation. The aim of the SMARTSOS system is to...
The paper describes the project “Integrated technologies for fire monitoring and first alert” proposed by the authors to satisfy technical requirements of the Firefighter Bodies with particular attention to the monitoring of wood fires and release of chemical materials. The target system is composed of three sub-systems: sensors to detect target parameters, telecommunications to transfer sensor data...
This paper addresses the definition and testing, through a network emulation platform, of satellite IP-based live video streaming. Specifically, a High Throughput Satellite (HTS) VSAT commercial service operating at Ka-band was considered as core network for IP data transport. This approach opens the way to the definition of a new live “low cost - high quality” contribution model, compared to the...
DVB-RCS2 is conceived to improve satellite channel flexibility in supporting a vast gamut of applications. In particular, a Bandwidth on Demand (BoD) MAC profile is allowed for bulk transfers typical of Internet applications. As assessed for previous DVB-RCS systems, TCP performance is seriously impaired in this context mainly because of large latency, further inflated by BoD access delay. In addition,...
Mobile user terminals allow to access different networks through several interfaces. Seamless communications is an essential requirement and service continuity is its main metric from user perspective. Mobile IPv6, ad-hoc routing, dynamic link layer protocol, SDN paradigm greatly facilitate mobility and network flexibility. Nonetheless, full mobility is limited by NAT routers or proxy agents, which...
Cloud computing can significantly improve efficiency in Internet utilization and data management. Several cloud applications (file sharing, backup, data up/download etc.) imply transfers of large amount of data without real-time requirements. In several use-cases cloud-computing solutions reduce operational costs and guarantee target QoS. These solutions become critical when satellite systems are...
Random Access (RA) techniques have been included in the novel DVB-RCS2 standard due to an expected efficiency in addressing SCADA and M2M traffic. Such traffic relies on intermittent sources sending short messages on a periodic time scale. Efficiency is usually assessed in terms of layer-2 packet loss rate without taking into account indirect effects on upper layer protocols. In particular, TCP assumes...
An efficient resource allocation is of paramount importance to guarantee the best performance with a fair distribution of satellite capacity, even for Multi-beam High Throughput Satellites (HTS) platforms. These platforms are recently gaining relevance for broadband Internet access and are nowadays able to provide xDSL like services. Although the available bandwidth for HTS is greater than previous...
SPDY is a recent Web technology aimed to improve webpages load time and resource utilization, through the implementation of: multiplexing and prioritization of webpage objects, header compression, resource pushing and encryption. Most of these techniques are already implemented in Performance Enhancing Proxies (PEPs), which are adopted in geostationary satellite systems to optimize TCP-based application...
New paradigms for web applications have motivated in recent years a series of proposals to update the Internet protocols. One of the proposed protocols is called SPDY, endorsed and developed by Google. This protocol at application layer is able to optimize Web page loading time, allowing additional features such as multiplexing, flow control and priority, and providing security as well. Some SPDY...
In satellite systems, notwithstanding recently launched systems have significantly increased bandwidth availability and improved cost effectiveness, the efficient resource management to achieve competitive final cost to the users, not renouncing to the right satisfaction in terms of quality of service, is of primary importance.
TCP Noordwijk manages very efficiently Internet traffic when a satellite link is included in the path. The improvement of the bandwidth estimator can further increase performance, especially in presence of competing traffic using other TCP protocols, and the exploitation of innovative service paradigms, first of all, cloud computing. In this respect, a meaningful increase of data transfers with different...
DVB-S/S2 is used to provide multimedia broadcasting and unidirectional IP based services over satellite networks, while DVB-RCS enhances transmission in a bidirectional way, enabling transmission over the satellite return channel.
Satellite systems can be fruitfully utilized to provide connectivity to terrestrial sensor networks to exploit large-scale monitoring applications based on IP protocol. Sensor traffic patterns are very different from those occurring with current Internet applications, so that performance evaluation requires some specific investigation with the aim to draw the main requirements to achieve target Quality...
Bandwidth in Satellite systems is a resource typically scarce and expensive. To increase efficiency and contain costs of satellite communications, bandwidth on demand (BoD) mechanisms are often employed, able to make shared resource utilization efficient. Adopting the proper Quality of Service (QoS) approach is of paramount importance to allow the optimal response and guarantee target performance...
TCP Noordwijk has been designed and implemented to optimize short transfers (i.e. HTTP traffic) over satellite links, while assuring good performance for long transfers (e.g., FTP) as well. It was developed in the frame of an European Space Agency (ESA) project [†]. Its target scenario is a controlled communication environment adopting DVB-RCS standard between I-PEPs. A rich test campaign to both...
To exchange medical data between two distant locations is of paramount importance in a significant number of scenarios (emergency, developing countries, home care, training, etc.). This paper presents performance evaluation, through emulation and using real medical equipment, of a Telemedicine application including Electro-encephalographic (EEG) data, audio, video and text. All the application flows...
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