1,190 research outputs found
Next Generation Optical Access Networks: from TDM to WDM
Postprint (author’s final draft
Using Dedicated and Opportunistic Networks in Synergy for a Cost-effective Distributed Stream Processing Platform
This paper presents a case for exploiting the synergy of dedicated and
opportunistic network resources in a distributed hosting platform for data
stream processing applications. Our previous studies have demonstrated the
benefits of combining dedicated reliable resources with opportunistic resources
in case of high-throughput computing applications, where timely allocation of
the processing units is the primary concern. Since distributed stream
processing applications demand large volume of data transmission between the
processing sites at a consistent rate, adequate control over the network
resources is important here to assure a steady flow of processing. In this
paper, we propose a system model for the hybrid hosting platform where stream
processing servers installed at distributed sites are interconnected with a
combination of dedicated links and public Internet. Decentralized algorithms
have been developed for allocation of the two classes of network resources
among the competing tasks with an objective towards higher task throughput and
better utilization of expensive dedicated resources. Results from extensive
simulation study show that with proper management, systems exploiting the
synergy of dedicated and opportunistic resources yield considerably higher task
throughput and thus, higher return on investment over the systems solely using
expensive dedicated resources.Comment: 9 page
Next Generation Optical Access Networks: from TDM to WDM
Postprint (author’s final draft
Service differentiation in multihop wireless packet networks
This work explores the potential of link layer scheduling combined with MAC layer prioritization for providing service differentiation in multihop wireless packet networks. As a result of limited power, multihop characteristic and mobility, packet loss ratio in wireless ad hoc networks tends to be high compared to wireline and one-hop mobile data networks. Therefore, for wireless ad hoc networks, DiffServ-like distributed service differentiation schemes are more viable than hard QoS solutions, which are mainly designed for wireline networks. The choice and implementation of proper queuing and scheduling methods, which determine how packets will use the channel when bandwidth becomes available, contributes significantly to this differentiation. Due to the broadcast nature of wireless communication, media access is one of the main resources that needs to be shared among different flows. Thus, one can design and implement algorithms also at MAC level for service differentiation. In this study, in addition to the scheduling discipline, IEEE 802.11 Distributed Coordination Function is used to increase the media access probability of a specific class of traffic. It is shown that the service requirements of a class can be better met using this two level approach compared to the cases where either of these schemes used alone
New dynamic bandwidth allocation algorithm analysis: DDSPON for ethernet passive optical networks
This project aims to present the state of the art in Dynamic Bandwidth Allocation (DBA) solutions, as well as the study and evaluation of one proposal of DBA algorithm: the Distributed Dynamic Scheduling for EPON (DDSPON), which is the UPC contribution to the research in scheduling algorithms for EPON
Implementing and Evaluating Security in O-RAN: Interfaces, Intelligence, and Platforms
The Open Radio Access Network (RAN) is a networking paradigm that builds on
top of cloud-based, multi-vendor, open and intelligent architectures to shape
the next generation of cellular networks for 5G and beyond. While this new
paradigm comes with many advantages in terms of observatibility and
reconfigurability of the network, it inevitably expands the threat surface of
cellular systems and can potentially expose its components to several cyber
attacks, thus making securing O-RAN networks a necessity. In this paper, we
explore the security aspects of O-RAN systems by focusing on the specifications
and architectures proposed by the O-RAN Alliance. We address the problem of
securing O-RAN systems with an holistic perspective, including considerations
on the open interfaces used to interconnect the different O-RAN components, on
the overall platform, and on the intelligence used to monitor and control the
network. For each focus area we identify threats, discuss relevant solutions to
address these issues, and demonstrate experimentally how such solutions can
effectively defend O-RAN systems against selected cyber attacks. This article
is the first work in approaching the security aspect of O-RAN holistically and
with experimental evidence obtained on a state-of-the-art programmable O-RAN
platform, thus providing unique guideline for researchers in the field.Comment: 7 pages, 5 figures, 1 table, submitted to IEEE Network Magazin
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