Mike J. O'Mahony

Bio: Mike J. O'Mahony is an academic researcher from University of Essex. The author has contributed to research in topics: Packet switching & Optical burst switching. The author has an hindex of 21, co-authored 83 publications receiving 2400 citations.

A Progressive Network Management Architecture Enabled By Java Technology

Abstract: This paper proposes a framework based completely on Java technology. The advantages brought about by the use of Java in network management answer some critical problems existing in current systems. With this work we address several factors concerning interoperability and security in heterogeneous network environments. Specifically, we present a manager application and a multithreaded agent engine that make use of a lightweight communication mechanism for message exchange. A MIB parser is introduced to accelerate handling of incoming management requests, and the RSA public-key cryptosystem is implemented to provide both encryption and authentication features. Results, measured in terms of response time, compare favourably with other published work and standard management frameworks.

Applications of Ultra-Short Pulse Sources in OTDM Networks

Abstract: Novel all-optical and high-speed time-multiplexed space (TMS) switch architectures can be realised with the use of ultra-short pulse sources and ultra-fast all-optical wavelength converters. Example architectures, which only require low speed electronics, are outlined. Experimental results from an associated time-slot interchange architecture demonstrate error-free performance at 40 Gbit/s. The proposed architectures can be used in a WDM/OTDM optical cross-connect node, able to switch circuits in space, wavelength, and time.

IST-OPTIMIST view on technology trends in optical networking

Abstract: Today there is a fast evolution in optical networking, both in terms of capacity and flexibility. This paper reviews some technological trends, such as optical circuit to optical packet switching, network control, layer integration, system evolution, etc. The paper is based on work in the IST Thematic Network project OPTIMIST (Optical Technologies in Motion for the IST Programme).

Deploying a Hierarchical Management Framework Using Mobile Agent Technology

Abstract: The use of Mobile Agent (MA) paradigm has been proposed by many researchers as an answer to the scalability and flexibility limitations of centralised Network Management (NM). Nevertheless, while large enterprise networks are already hierarchically structured, MA-based management has not yet moved from ‘flat’ to hierarchical structures. That results in non-scalable flat architectures, particularly when the management of remote subnetworks is considered. In this context, the deployment of a hierarchically structured MA-based management framework is a reasonable approach. The migration to hierarchical structures is achieved with an additional management entity, the Mobile Distributed Manager (MDM), which takes the full control of managing a given network segment. This architecture exploits the mobility features of MDMs to dynamically adapt to mutable networking conditions. Empirical results indicate a substantial reduction of the overall management cost compared to both centralised and MA-based flat management approaches.

Erbium-doped fibre pre-amplifier with an integral band-pass filter

Abstract: The authors have shown that significant optical gain improvements can be achieved by inserting a narrow band-pass filter within the erbium-doped fibre amplifiers length to suppress the built-up of both forward and backward ASE powers, accompanied by a noise figure reduction of 0.6-0.8 dB. The optimum filter position is found to be around 48% and 42% from the input end of the total amplifier length for 1.48 mu m and 0.98 mu m pump wavelengths respectively.

Optical burst switching (OBS) - a new paradigm for an optical Internet

Abstract: To support bursty traffic on the Internet (and especially WWW) efficiently, optical burst switching (OBS) is proposed as a way to streamline both protocols and hardware in building the future gener...

On Global Electricity Usage of Communication Technology: Trends to 2030

Abstract: This work presents an estimation of the global electricity usage that can be ascribed to Communication Technology (CT) between 2010 and 2030. The scope is three scenarios for use and production of consumer devices, communication networks and data centers. Three different scenarios, best, expected, and worst, are set up, which include annual numbers of sold devices, data traffic and electricity intensities/efficiencies. The most significant trend, regardless of scenario, is that the proportion of use-stage electricity by consumer devices will decrease and will be transferred to the networks and data centers. Still, it seems like wireless access networks will not be the main driver for electricity use. The analysis shows that for the worst-case scenario, CT could use as much as 51% of global electricity in 2030. This will happen if not enough improvement in electricity efficiency of wireless access networks and fixed access networks/data centers is possible. However, until 2030, globally-generated renewable electricity is likely to exceed the electricity demand of all networks and data centers. Nevertheless, the present investigation suggests, for the worst-case scenario, that CT electricity usage could contribute up to 23% of the globally released greenhouse gas emissions in 2030.

Advances in photonic packet switching: an overview

Abstract: The current fast-growing Internet traffic is demanding more and more network capacity every day. The concept of wavelength-division multiplexing has provided us an opportunity to multiply network capacity. Current optical switching technologies allow us to rapidly deliver the enormous bandwidth of WDM networks. Photonic packet switching offers high-speed, data rate/format transparency, and configurability, which are some of the important characteristics needed in future networks supporting different forms of data. In this article we present some of the critical issues involved in designing and implementing all-optical packet-switched networks.