Interference and communications among active network applications

This paper focuses on active networks applications and in particular on the possible interactions among these applications. Active networking is a very promising research field which has been developed recently, and which poses several interesting challenges to network designers. A number of proposals for e±cient active network architectures are already to be found in the literature. However, how two or more active network applications may interact has not being investigated so far. In this work, we consider a number of applications that have been designed to exploit the main features of active networks and we discuss what are the main benefits that these applications may derive from them. Then, we introduce some forms of interaction including interference and communications among applications, and identify the components of an active network architecture that are needed to support these forms of interaction. We conclude by presenting a brief example of an active network application exploiting the concept of interaction

Relationships among Inter-Dependent Real-Time Strams

: Multicast real-time streams assume in general the shape of a tree where the source is the root and the receivers are the leaves. Many common networked multimedia applications need to create a large number of such streams to connect the end-peers one to each other. Often, relationships among the streams created by the same or related applications exist. Being able to express these relationships makes it possible to optimize the global utilization of the network resources. This paper suggests the concept of groups of streams to express such relationships and defines a set of basic relationships that are felt of immediate importance for emerging networked multimedia applications. The way global network resources can be optimally exploited is also presented. The results can be easily applied to existing setup protocols. Keywords: real-time stream, quality of service, group, relationship, resource sharing, setup protocol. 1 Introduction Distributed multimedia applications exploit conti..

Trust issues for vehicular ad hoc networks

Abstract—Characteristics and requirements of vehicular ad hoc networks (VANETs) differ quite significantly compared to standard ad hoc networks. Especially trust in VANETs is very important but still open issue, which will be addressed in this paper. We will describe, discuss and assess approaches and concepts that were proposed in ordinary fixed networks and mobile ad hoc networks and will show weak and strong spots. As basis for our considerations, we will describe a detailed automotive scenario, which relies on inter-vehicle communication for the exchange of safety relevant warning messages. I

Perspectives of Electronic Commerce: the Italian Scenario

This paper provides a brief overview on the current state and future perspectives of electronic commerce activities in Italy. As most European countries, Italy is currently experiencing a large number of initiatives focused on electronic commerce at different levels: new business organizations are being created, traditional enterprises are being reorganized to change their focus on innovative forms of business, banks and financial institutions are exploiting the new opportunities offered by trading online services. At the same time, the first attempts to regulate Internet-based business activities have appeared and some forms of incentive are being planned by the Government. The task of monitoring these activities, understanding their dynamics and predicting their evolution is, of course, extremely complex and a complete analysis goes beyond the purpose of this paper: within this work, we intend to present the information that it is felt most relevant and present a scenario that can as accurately as possible reflect current developments in Italy. The rest of this paper is organized as follows: first, we present estimates on the potential growth of electronic commerce in Italy and we compare the expected Italian growth with that of other European countries; then, we briefly discuss the quality of web applications currently adopted by the electronic vendors in their virtual shops and what are the main driving forces and concerns behind their efforts; after this, we try to sketch the profile of the Italian customer of online products and understand his behavior and the type of products he or she is more likely to buy; finally, we discuss some issues related to the regulation in our country

Issues of Reserving Resources in Advance

: Resource management offers Quality-of-Service reliability for timecritical continuous-media applications. Currently existing resource management systems provide only means to reserve resources starting with the reservation attempt and lasting for an unspecified duration. However, for several applications such as video conferencing the ability to reserve the required resources in advance is needed. This paper explains a model for resource reservation in advance. We identify and discuss issues which must be resolved in resource reservation in advance systems. Some of the possible scenarios to be considered are described and we show how the resource reservation in advance scheme can be embedded in a general architecture. 1 Introduction Computer systems used for continuous media processing have to be able to cope with streams with data rates of several Mbits/s and to provide timely processing guarantees, for instance such that an endsystem shall synchronize audio and video streams up to..

Reservation Protocols for Internetworks: A Comparison of ST-II and RSVP

: Although efforts on reservation protocols for internetworks started quite some time ago, the research community is now becoming particularly active in this area, as proved by the high interest generated by protocols such as ST-II and RSVP. These two protocols, starting from different assumptions, have the common goal of providing guaranteed communication by reserving network bandwidth. This paper provides a short comparison of the two protocols. It describes and compares their mechanisms, focusing on the data forwarding, multicast, and quality of service aspects for multimedia communication. Rather than trying to decide which protocol is superior, we have identified the classes of applications which are better supported by one or the other protocol. 1 Introduction For multimedia communication, i.e., the transmission of digital audio and video, three issues are widely believed to be important: 1. fast data forwarding, 2. multicast, and 3. service guarantees. Each multimedia communica..