SG6 - Networks, Telematic and New Services

Research Unit 6 (RU6) of Computer Technology Institute & Press "Diophantus" is located in Building B of University of Patras and consists of 11 members. RU6 exhibits substantial research activity in the following areas:

• Mobile Networks: RU6 conducts research on mobile networks proposing innovative techniques in order to meet the Next Generation Mobile Networks high performance demands and contributing on the simulation and evaluation of existing and proposed technologies.

In the past, we focused on Universal Mobile Telecommunications System (UMTS) and High Speed Packet Access (HSPA) networks and specifically on the field of multicasting over UMTS, through the Multimedia Broadcast/Multicast Service (MBMS). We also developed novel analytical models and simulations in order to examine the coverage, capacity and spectral efficiency of MBSFN (MBMS over a single frequency network), proposed to deliver multicast services over Long Term Evolution (LTE) systems. Moreover, we focus on improving the overall performance of Long Term Evolution Advanced (LTE-A) networks through frequency reuse schemes and femtocell technology.

• Next Generation Networks: RU6 research in this area deals with the latest developments in wired networks, including the design, implementation, simulation and testing of existing and proposed technologies.

RU6 has been actively involved in the design, development and operation of a Bandwidth on Demand (BoD) service developed by the pan-European research and academic network GEANT that is able to provide on demand circuits across heterogeneous optical networks, including SDH, Ethernet and MPLS-based backbones. Furthermore, RU6 works on the design and implementation of Quality of Service (QoS) mechanisms based on the MPLS technology and the DiffServ architecture. Also, RU6 works in the area of transitioning mechanisms from IPv4 to IPv6 and on testing QoS mechanisms on IPv6 domains.

Moreover, RU6 focuses on the design of Broadband Fiber Optic Metropolitan Area Networks (MAN), and FFTH/FTTB networks, based on open standards.

Finally, RU6 is involved in the design of techno-economic models and the business plans for the deployment and (viable) exploitation of these FTTH/FTTB networks.

• Cross Layer (Design and Mechanisms): In terms of power management in Wireless Networks, RU6 has implemented several innovative frameworks that aim to the efficient power management for content delivery over the 802.11 wireless standard.

Furthermore, RU6 has designed several cross layer mechanisms on Multimedia/Video Transmission in MANETs/Ad-hoc Networks. More precisely, these mechanisms use the information of the Physical Layer to adapt several transmission parameters in both the Network and Application Layers, and vice-versa information of the Application Layer to affect priority handling in both the Network and Physical Layer.

• Network Simulations and Field Tests: RU6 has used and extended various simulation tools such as ns-2, ns-3 and OMNET++, as well as field tests, for experimental research.

RU6 extended the ns-2 functionality towards the direction of realistic traffic generation and a series of mechanisms defined by the DiffServ architecture (in the case of the DiffServ framework, simulation is valuable due to the fact that an analytical approach of mechanisms and services is infeasible because of the aggregation and multiplexing of flows). RU6 also extended ns-2 with the functionality of Bandwidth Brokers, which are entities for managing the resources and negotiating end to end resource reservations between domains. The implementation and deployment complexity of such solutions makes it useful to be able to inexpensively study related research issues in a simulation environment.

Moreover, RU6 has extended ns-2 functionality by implementing modules for third generation cellular networks and in particular aspects of the Universal Mobile Telecommunications System (UMTS). These modules include functionality such as adaptive multimedia transmission, multicast routing, user mobility etc.

Furthermore, RU6 implemented, in ns-2, mechanisms for efficient power management during content transmission (such as video) over 802.11 wireless networks. These mechanisms were also implemented and tested in real environment using the Linux operating system.

Also, RU6 implemented several simulation models, in ns-2 (and currently in ns-3),for video transmission in MANETs.

In addition, RU6 introduced several simulation models over LTE systems utilizing MATLAB and implementing extensions for ns-3. These simulation models include: a tool for MBSFN area optimization based on spectral efficiency and cost, a mobility-sensitive tool for MBSFN area optimization based on power control, a throughput simulation framework for LTE-A systems and a simulation framework for power management over femtocells in LTE-A systems.

Finally, in order to ease the management of trace files generated during network simulations, RU6 has developed a simulation analysis tool.

For more information related to the people, the publications, the research areas and the projects please visit the website of Research Unit 6.