Evangelos Papapetrou | University of Ioannina/Greece (original) (raw)

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Papers by Evangelos Papapetrou

19TH IEEE INTERNATIONAL SYMPOSIUM ON A WORLD OF WIRELESS, MOBILE AND MULTIMEDIA NETWORKS (WOWMOM 2018), 2018

Mutli-copy routing is an efficient and widespread approach for coping with the intermittent conne... more Mutli-copy routing is an efficient and widespread approach for coping with the intermittent connectivity of mobile opportunistic networks. One popular multi-copy approach is known as " dynamic " replication; each node creates replicas on a contact basis using a utility that determines a node's fitness for delivering a message to its destination. This scheme is highly flexible, configurable with different utility functions and able to operate efficiently in networks with diverse characteristics. Nonetheless, its drawback is the tendency to produce a high number of replicas that consume limited resources such as energy and storage. Our approach to tackle this problem relies on the observation that, based on their utility values, the network nodes can be grouped into clusters that portray different delivery capabilities. Then, to avoid unnecessary replication, we exploit this finding to replicate a packet to nodes that belong to clusters with increasing delivery capability instead of replicating it to nodes with increasing utility. The new method works in synergy with the basic dynamic replication algorithms and is fully configurable, in the sense that it can be used with virtually any utility function. By conducting experiments in a diverse set of real-life networks, we empirically show that the method effectively reduces the overall number of replicas without hindering delivery efficiency.

2007 IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications, 2007

QShine 2007 Workshop: Satellite/Terrestrial Interworking on - IWSTI '07, 2007

2013 IEEE 24th Annual International Symposium on Personal, Indoor, and Mobile Radio Communications (PIMRC), 2013

2014 IEEE 10th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob), 2014

Network coding is commonly used to improve the energy efficiency of network-wide broadcasting in ... more Network coding is commonly used to improve the energy efficiency of network-wide broadcasting in wireless multi-hop networks. In this work, we focus on XOR-based broadcasting in mobile ad hoc networks with multiple sources. We make the observation that the common approach, which is to benefit from the synergy of XOR network coding with a CDS-based broadcast algorithm, suffers performance breakdowns. After delving into the details of this synergy, we attribute this behavior to an important mechanism of the underlying broadcast algorithm, known as the " termination criterion ". To tackle the problem, we propose a termination criterion that is fully compatible with XOR coding. In addition to that, we revisit the internals of XOR coding. We first enhance the synergy of XOR coding with the underlying broadcast algorithm by allowing each mechanism to benefit from information available by the other. In this way, we manage to improve the pruning efficiency of the CDS-based algorithm while at the same time we come up with a method for detecting coding opportunities that has minimal storage and processing requirements compared to current approaches. Then, for the first time, we use XOR coding as a mechanism not only for enhancing energy efficiency but also for reducing the end-to-end-delay. We validate the effectiveness of our proposed algorithm through extensive simulations on a diverse set of scenarios.

—Network coding has been successfully used in the past for efficient broadcasting in wireless mul... more —Network coding has been successfully used in the past for efficient broadcasting in wireless multi-hop networks. Two coding approaches are suitable for mobile networks; Random Linear Network Coding (RLNC) and XOR-based coding. In this work, we focus on the problem of multiple source broadcasting in mobile ad hoc networks. We make the observation that RLNC provides increased resilience to packet losses compared to XOR-based coding. We develop an analytical model that justifies our intuition. However, the model also reveals that combining RLNC with probabilistic forwarding, which is the approach taken in the literature, may significantly impact RLNC's performance. Therefore, we take the novel approach to combine RLNC with a deterministic broadcasting algorithm in order to prune transmissions. More specifically, we propose a Connected Dominating Set (CDS) based algorithm that works in synergy with RLNC on the " packet generation level ". Since managing packet generations is a key issue in RLNC, we propose a distributed scheme, which is also suitable for mobile environments and does not compromise the coding efficiency. We show that the proposed algorithm outperforms XOR-based as well as RLNC-based schemes even when global knowledge is used for managing packet generations. Index Terms—random linear network coding, broadcasting, mobile ad hoc networks

2007 IEEE International Conference on Communications, Jun 2007

In this paper we address the problem of efficiently distributing query messages among peers in a ... more In this paper we address the problem of efficiently distributing query messages among peers in a wireless ad hoc network. We assume that peers are organized in classes. Each peer possesses a local database and can answer queries posed by other peers. Each peer can also pose queries to all the peers belonging to a certain class and/or within a certain range of distance in the network. Contrary to traditional p2p lookup queries, we are interested in collecting answers from as many peers as possible. To efficiently serve this purpose, we take advantage of routing and application layer specifics (e.g., class information, network distance) to avoid flooding and at the same time preserve compatibility with traditional routing and transport mechanisms.

International Conference on Telecommunications (ICT'00)

GLOBECOM'01. IEEE Global Telecommunications Conference (Cat. No.01CH37270), 2001

Wireless Personal Communications, 2005

International Journal of Wireless Information …, 2001

Notwithstanding the limited commercial success of the first narrowband Low Earth Orbit (LEO) sate... more Notwithstanding the limited commercial success of the first narrowband Low Earth Orbit (LEO) satellite systems, the interest of the scientific community in this type of systems has been revived on the basis of the current trend toward the migration to all IP-based services. LEO systems can play a pivotal role in providing services to areas where there is no substantial terrestrial infrastructure. Above all, LEO satellite systems can be used as backbone networks to interconnect autonomous systems worldwide. Such an approach provides flexibility in managing the resulting integrated network infrastructure and supporting innovative applications. In this context, routing data from the source all the way to the destination constitutes a daunting challenge. In this paper, a location-assisted on-demand routing (LAOR) protocol
is proposed and evaluated. The proposed protocol introduces for the first time in satellite systems the concept of on-demand routing. However, its implementation is tailored to the requirements imposed by the characteristics of the topology of LEO satellite systems. The performance of the LAOR protocol is
assessed for di®erent link-cost metrics and compared to the one of centralized routing protocols proposed in the literature so far. Simulation studies further document and confirm the positive characteristics of
the proposed protocol.

2007 IEEE International Conference on Communications, 2007