George Xylomenos

Abstract—In this paper we explain how efficient delivery of real-time information can be supported in the Publish Subscribe Internet (PSI), a network architecture proposal for the Future Internet. PSI departs from IP thinking with respect to the core abstractions made and the functional organization of the system. PSI places information at the heart of the network layer and decouples the forwarding, path formation and topology management functionalities. This design approach can be highly beneficial for real-time ...

Information-centric networking constitutes an alter-native to the conventional, IP-based internetworking, with in-formation being identified rather than the host where it resides (which is the case for IP networking). This approach appears to be very promising for the next generation Internet. However, many challenges and critical issues remain to be addressed, asso-ciated with the range of applications that can be supported by the new architectures. Specifically, it is unclear whether information-centric networking abstractions can support conversational ap-plications which are very important in the Internet, and even more important in other telecommunication networks. In light of those reflections, we present the design, prototype implementation and performance evaluation of a simple voice application for the Publish-Subscribe Internet architecture developed in PSIRP and now being further refined in PURSUIT, two EU FP7 research projects on clean slate Future Internet design. Index...

We present preliminary work on a sensor-based system that we are currently implementing with the aim of monitoring the health of the elderly and people with special needs. The system functions both inside and outside the home of the monitored individuals, using sensors and GPS-enabled cellular phones. Its objective is to first learn the daily behavior of the monitored individuals, and then detect changes in their routines and health status, providing alerts and a preliminary diagnosis as quickly as possible when something out of the ordinary occurs.

INTRODUCTION The current strong drive towards Internet access via mobile terminals, makes the inclusion of wireless systems such as Cellular Communications (CC) and Wireless Local Area Networks (WLAN) into the mainstream Internet very desirable. CC and WLAN systems however raise a multitude of performance issues, since environmental conditions and terrestrial obstructions and reflections lead to high and unpredictable error rates. CC and WLAN systems mostly share the characteristics of traditional wireless systems (satellite and terrestrial microwave), such as high error rates. They also share some of the characteristics of wired systems, such as low physical layer propagation delays. As a result, in order to improve their performance, a synthesis of techniques for enhancing the performance of both wired and wireless links is required, that will also take into account the requirements of the TCP/IP protocol suite. In this chapter we present the characteristics and performance limitati

In this paper, we focus on the bootstrap operation of a publish/subscribe information centric network. We consider a set of interconnected network nodes and describe how they organize themselves into a fully functional network by pub-lishing and subscribing to control plane information. Network bootstrap includes establishing point-to-point communication between network elements, exchanging topological information and setting up the rendezvous system. We showcase the network's publish/subscribe service with a complete example.

While BitTorrent was originally conceived as a Peer-to-Peer file exchange protocol, it has proved extremely successful for asynchronous content distribution, allowing content sources to support huge numbers of users with a modest amount of bandwidth. This has prompted many researchers to study the possibility of using BitTorrent to support real-time media streaming. In this paper we present a comparison of three proposed adaptations to BitTorrent for media streaming, using our detailed packet-level BitTorrent simulator. Unlike previous evaluations which assumed that the streaming media player would drop data that did not arrive on time, in this paper we use a more realistic model where the player stalls when data are not available, thus placing emphasis on delays rather than losses. Our experiments indicate that under this, more realistic, evaluation model, user level performance can be quite reasonable.

ABSTRACT Overlay networks are widely used for locating and disseminating information by means of custom routing and forwarding on top of an underlying network. Distributed Hash Table (DHT) based overlays in particular, provide good scalability and load balancing properties. However, these come at the cost of inefficient routing, caused by the lack of adaptation to the underlying network, as DHTs often overlook physical network proximity, administrative boundaries and/or inter-domain routing policies. In this paper we show how to construct a DHT-based overlay network that takes all these aspects into account, so as to ease the global deployment of Future Internet architectures which require large-scale name resolution, such as Information-Centric Networking (ICN) and the Internet of Things (IoT). Based on the Pastry distributed object location and routing substrate and the Canon paradigm for multi-level DHTs, we developed H-Pastry, an overlay DHT scheme that harvests the scalability and load balancing features of DHTs, while also adapting to the underlying network topology, administrative structure and routing policies. We evaluate the performance characteristics of the proposed scheme through an extensive set of detailed simulations over realistic inter-network topologies. Our results show that H-Pastry substantially improves routing by reducing both overlay path stretch (by up to 55%) and routing policy violations (by up to 70%), compared to the Canonical (multi-level) Chord DHT. In addition, the design of H-Pastry keeps traffic within administrative boundaries as far as possible, reducing inter-domain hops by up to 27% compared to Pastry, while also creating excellent opportunities for the support of caching and multicast.

Abstract Having identified important limitations of the current Internet architecture, several research initiatives have engaged in the design of new architectures for the Internet of the Future. New features and protocols are designed, and in many cases, a clean slate approach is followed, advocating the replacement of almost the entire current protocol stack. In order to reliably evaluate the performance of such emerging protocols and architectures, we need a realistic evaluation framework reflecting current and forecasted traffic patterns. ...

While multicasting is considered valuable for con- tent distribution, it is not widely supported on the Internet, despite the emergence of scalable overlay schemes. Content providers have instead turned to peer assisted content distri- bution in order to efficiently serve large numbers of clients, thus removing the bandwidth bottleneck from their side but placing a heavy burden on the clients.

The Multimedia Broadcast/Multicast Service (MBMS) was recently standardized for use by 3rd Generation cellular networks, aiming to support the economical distribution of multimedia content to large numbers of receivers. This paper proposes an MBMS extension supporting the distribution of multiple variants of the same content to heterogeneous receivers. We first outline the standard MBMS model, along with its state management

This paper describes and analyzes an extension of the Multimedia Broadcast / Multicast Service (MBMS) that supports the distribution of multiple variants of the same content to heterogeneous receivers. We first outline the standard MBMS model and then describe our extended MBMS model, detailing the modifications that it imposes on MBMS state management and signaling procedures. We then provide an