Edges as Nodes - a New Approach to Timetable Information

In this paper we suggest a new approach to timetable information by introducing the ``edge-converted graph'' of a timetable. Using this model we present simple algorithms that solve the earliest arrival problem (EAP) and the minimum number of transfers problem (MNTP). For constant-degree graphs this yields linear-time algorithms for EAP and MNTP which improves upon the known \emph{Dijkstra}-based approaches. We also test the performance of our algorithms against the classical algorithms for EAP and MNTP in the time-expanded model

Experimental Evaluation of Dynamic Resource Orchestration in Multi-Layer (Packet over Flexi-Grid Optical) Networks?

This paper has been presented at : ONDM 2019 23rd Conference on Optical Network Design and ModellingIn future 5G infrastructures, network services will be de- ployed through sets of Virtual Network Functions (VNFs) leveraging the advantages of both Software Defined Networking (SDN) and Net- work Function Virtualization (NFV). A network service is composed of an ordered sequence of VNFs, i.e., VNF Forwarding Graph (VNFFG), deployed across distributed data centers (DCs). Herein, we present a Cloud/Network Orchestrator which dynamically processes and accom- modates VNFFG requests over a pool of DCs interconnected by a multi- layer (packet/flexi-grid optical) transport network infrastructure. We propose two different cloud and network resource allocation algorithms aiming at: i) minimizing the distance between the selected DCs, and ii) minimizing the load (i.e., consumed cloud resources) of the chosen DCs. Both algorithms run on a Cloud/Network Orchestrator and are ex- perimentally validated and benchmarked on the CTTC ADRENALINE testbed.This work is partially funded by the EU H2020 5G TRANSFORMER project (761536) and the Spanish AURORAS project (RTI2018-099178

Profile Based Topology Control and Routing in Wireless Optical Networks

The problem of topology control and routing of bandwidth-guaranteed flows over wireless optical backbone networks is addressed. The input is a potential topology and a traffic profile. The constraints are that of limited interfaces at each node and the limited link bandwidth, and the objective is to maximize the throughput. The problem turns out to be NP-Hard. A new framework for integrated topology control and routing is proposed. A simple heuristic is proposed, and efficient rollout algorithms are proposed which enhance the heuristic. The routing problem is formulated as a multi-commodity flow problem, and is used to enhance the rollout algorithms to achieve a higher throughput. Another set of heuristics is proposed which use matching theory and multi-commodity flow formulation of routing to achieve the desired results. We enhance the heuristics to provide fairness to the ingress-egress pairs in terms of how much traffic we route for each of them

Design and validation of a meter band rate in OpenFlow and OpenDaylight for optimizing QoS

Technological developments in the Internet and communications have created a vastly complex and dynamic context with diverse heterogeneous networks and fast growth of mobile devices and multimedia. As the Internet becomes the primary mode of communication for many organisations there is requirement to enhance quality of service (QoS) from heterogeneous systems and networks. Traditional networks such as TETRA have become increasingly incapable of addressing the demand for media rich, bandwidth intensive traffic flows and applications. Mission-critical multimedia over new generation mobile networks face QoS constraints. This research explores a novel solution for quality of service performance for streaming mission-critical video data in OpenFlow SDN networks. A Meter Band Rate Evaluation (MBE) mechanism is advanced that improves the native QoS capability of OpenFlow and OpenDaylight. The MBE is a physical component added to the OpenFlow meter table to evaluate and dynamically adjust traffic rates and allows the traffic volume to be specified relative to other traffic in the network. Its design and development are presented and the mechanism is verified through a simulated experiment in an SDN testbed. The results identified that QoS performance experienced a significant percentage increase when the MBE was active. These findings contribute a novel Meter Band Rate Evaluation mechanism that extends the native capability of OpenFlow and OpenDaylight to enhance the efficiency of QoS provision