Michael Georgiades
University of Surrey
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Publication
Featured researches published by Michael Georgiades.
IEEE Wireless Communications | 2004
Christos Politis; Kar Ann Chew; Nadeem Akhtar; Michael Georgiades; Rahim Tafazolli; Tasos Dagiuklas
This article presents a multilayer mobility management scheme for all-IP networks where local mobility movements (micro-mobility) are handled separately from global movements (macro-mobility). Furthermore, a hybrid scheme is proposed to handle macro-mobility (mobile IP for non-real-time services and SIP for real-time services). The internetworking between micromobility and macro-mobility is implemented at an entity called the enhanced mobility gateway. Both qualitative and quantitative results have demonstrated that the performance of the proposed mobility management is better than existing schemes. Furthermore, a context transfer solution for AAA is proposed to enhance the multilayer mobility management scheme by avoiding the additional delay introduced by AAA security procedures.
european conference on networks and communications | 2015
Dirk Trossen; Martin J. Reed; Janne Riihijärvi; Michael Georgiades; Nikos Fotiou; George Xylomenos
This paper presents a proposition for information centric networking (ICN) that lies outside the typical trajectory of aiming for a wholesale replacement of IP as the internetworking layer of the Internet. Instead, we propose that a careful exploitation of key ICN benefits, expanding previously funded ICN efforts, will enable individual operators to improve the performance of their IP-based services along many dimensions. Alongside the main motivation for our work, we present an early strawman architecture for such an IP-over-ICN proposition, which will ultimately be implemented and trialed in a recently started H2020 research effort.
vehicular technology conference | 2008
Meng Wang; Michael Georgiades; Rahim Tafazolli
System architecture evolution (SAE) is one of the key challenges for the long term evolution(LTE) of 3G research, charted by 3GPP, aiming to develop a new core network for improving the IP based packet-switched network performance. This paper considers different mobility management schemes for different SAE core network architectural options proposed in 3GPP, and evaluates their performance according to signalling cost by using analytical modelling based on the random walk model. Our analysis shows that the mobility management performance of the different options on both Idle and Active mode. Regarding the architecture, options 2 and 3 have the best trade-off in total signalling cost performance in both modes and signalling load on each network node for system scalability. For mobility management, Proxy MIPv6 has shown that it is able to effectively reduce the signalling cost for mobility management for all architecture options.
IEEE Wireless Communications | 2008
Eranga Perera; Roksana Boreli; Stephen Herborn; Michael Georgiades; Jochen Eisl; Eleanor Hepworth
The future Internet will need to cater to an increasing number of mobile devices and mobile networks, roaming across different access networks and trust domains. In addition, various limitations imposed by the end user, service provider, or network operator agreements and preferences will need to be considered. A plethora of mobility management protocols have been proposed to handle different and mostly limited sets of these mobility requirements. In this article we make the case for coexistence of mobility protocols in order to support the large range of mobility scenarios possible in future all-IP networks. This coexistence takes the form of a mobility toolbox that enables mobility handling mechanisms to be selected according to the context. We then present a design for the mobility toolbox as a component of the ambient networks architecture, including a simplified mobility tool interface toward protocol modules, and show how it meets the requirements of future all-IP networks. We further demonstrate the feasibility and performance gains of the mobility toolbox architecture with a prototype implementation based on network mobility.
Computer Communications | 2007
Michael Georgiades; Nadeem Akhtar; Christos Politis; Rahim Tafazolli
In an all-IP-based network architecture that provides multimedia services for 3G and WLAN users, security provisioning is a paramount requirement. However, a security infrastructure (e.g., AAA) introduces additional impairments, in the form of delay components, to the total handoff performance crucially affecting the prime objective towards seamless and secure mobility. In this work, a Context Transfer solution is proposed, in order to support seamless and secure multimedia services over all-IP infrastructures. The solution acts as an adhesive between the AAA and mobility management entities by using the latter to forward AAA state information locally. In this solution, the mobility management protocol is used to trigger Context Transfer and additional messages have been introduced to carry the desired AAA context information. The results presented here show that the overall handoff delay is reduced significantly and a considerable improvement is seen in the performance of real-time and non-real-time applications.
Optics Express | 2013
Bijan Rahimzadeh Rofoee; Georgios Zervas; Yan Yan; Dimitra Simeonidou; Giacomo Bernini; Gino Carrozzo; Nicola Ciulli; John Levins; Mark Basham; John Dunne; Michael Georgiades; Alexander Belovidov; Lenos Andreou; David Sanchez; Javier Aracil; Victor Lopez; J. P. Fernandez-Palacios
This paper reports on the first user/application-driven multi-technology optical sub-wavelength network for intra/inter Data-Centre (DC) communications. Two DCs each with distinct sub-wavelength switching technologies, frame based synchronous TSON and packet based asynchronous OPST are interconnected by a WSON inter-DC communication. The intra/inter DC testbed demonstrates ultra-low latency (packet-delay <270 µs and packet-delay-variation (PDV)<10 µs) flexible data-rate traffic transfer by point-to-point, point-to-multipoint, and multipoint-to-(multi)point connectivity, highly suitable for cloud based applications and high performance computing (HPC). The extended GMPLS-PCE-SLAE based control-plane enables innovative application-driven end-to-end sub-wavelength path setup and resource reservation across the multi technology data-plane, which has been assessed for as many as 25 concurrent requests.
vehicular technology conference | 2007
Ramón Agüero Calvo; Abigail Surtees; Jochen Eisl; Michael Georgiades
Allowing a user to remain connected to the network whilst on the move is becoming a common requirement for any new communication system. The EU project Ambient Networks, therefore, considers mobility requirements and techniques in some depth. Two key ideas have been developed: the handover toolbox which contains and manages a variety of mobility protocols, handover techniques and, in particular, mobility optimisations; and the concept of routing groups, the establishment of which enables the mobility optimisations such as delegation of mobility management and aggregation of mobility signalling. In this paper we present these ideas and show how they are aligned with the ambient networks principles of being easily deployable, adaptable, and able to support heterogeneous network configurations.
2013 IEEE SDN for Future Networks and Services (SDN4FNS) | 2013
Kostas Katsalis; Thanasis Korakis; Giada Landi; Giacomo Bernini; Bijan Rahimzadeh Rofoee; Shuping Peng; Markos P. Anastasopoulos; Anna Tzanakaki; Dora Christofi; Michael Georgiades; Renaud Larsen; Jordi Ferrer Riera; Eduard Escalona; Joan A. Garcia-Espin
Although cloud computing and the Software Defined Network (SDN) framework are fundamentally changing the way we think about network services, multi-domain and multi-technology problems are not sufficiently investigated. These multi-domain, end-to-end problems concern communication paths that span from the wireless access and the wireless backhaul networks to the IT resources through optical networks. In this paper we present the CONTENT project approach to network and infrastructure virtualization over heterogeneous, wireless and metro optical networks, that can be used to provide end-to-end cloud services. The project goal is to drive innovation across multi-technology infrastructures and allow ICT to be delivered and consumed as a service by Virtual Network Operators. The communication mechanics between wireless and optical domains and the physical layer abstractions of a CONTENT Virtual Network are presented and the relation of the proposed approach with the SDN framework is investigated.
International Journal of Internet Protocol Technology | 2008
Michael Georgiades; Klaus Moessner; Tasos Dagiuklas
Ambient Networks (AN) aim to embrace the heterogeneity arising from different network technologies such that it appears homogeneous to the potential users at the level of network service provisioning. This paper focuses on the employment of a State Transfer Module (STM) in AN for enhancing mobility and minimising the impact of multimedia service discrepancy (e.g., security, session continuity) by supporting the transfer of authentication and authorisation states upon handoff as well as supporting multimedia session continuation while the users roam and handoff across heterogeneous wireless networks.
international conference on wireless communications and mobile computing | 2006
Michael Georgiades; Tasos Dagiuklas; Rahim Tafazolli
This paper describes a mechanism of forwarding secure state information associated to communication sessions, between middleboxes belonging to different Radio Access Networks (RANs). The transfer of state information among RANs could support service integrity and continuity by maintaining a mobile users multimedia sessions which may otherwise be dropped and also minimize security vulnerabilities. The paper demonstrates how the context transfer protocol could be employed for this purpose to forward certain security information from the old to the new middlebox to support multimedia session maintenance during mobility and also at the same time notify the previous middlebox to close unnecessary open ports for improved security and resolve vulnerability. A number of test scenarios are used to demonstrate how middleboxes could intervene with multimedia sessions during mobility and show how context transfer can provide a solution for improving the performance in the multimedia session re-establishment as well as enhancing middlebox security.