Network Coding for Energy Efficiency in Bypass IP/WDM Networks

Network coding has been proven to be an effective approach towards achieving the network capacity and resources efficiency. However, most of the work achieved has been under the umbrella of wireless networks. In this paper we investigate the use of network coding to improve energy efficiency of the IP/WDM optical core considering unicast traffic flows by implementing coding at the optical layer of intermediate nodes. The mixed integer linear programming results show that network coding can improve the energy efficiency by up to 28% on the NSFNET compared to conventional non-bypass approach. The results show that the network coded bypass approach also outperforms the conventional bypass approach

Energy Efficient Core Networks Using Network Coding

In this paper we investigate the use of network coding to improve energy efficiency of core networks. A mixed integer linear programming model is developed to optimize routing in network coding enabled non-bypass IP/WDM networks considering unicast traffic flows. We quantify the power savings obtained by implementing network coding. The results show that network coding can improve the energy efficiency of non-bypass IP/WDM networks by up to 33% compared to conventional architectures

Server-Centric PON Data Center Architecture

Over the last decade, the evolution of data center architecture designs has been mainly driven by the ever increasing bandwidth demands, high power consumption and cost. With all these in mind, a significant potential to improve bandwidth capacity and reduce power consumption and cost can be achieved by introducing PONs in the design of the networking fabric infrastructure in data centers. This work presents a novel server-centric PON design for future cloud data center architecture. We avoided the use of power hungry devices such as switches and tuneable lasers and encouraged the use of low power passive optical backplanes and PONs to facilitate intra and inter rack communication. We also tackle the problem of resource provisioning optimization and present our MILP model results for energy efficient routing and resource provisioning within the PON cell. We optimized the selection of hosting servers, routing paths and relay servers to achieve efficient resource utilization reaching 95% and optimum saving in energy consumption reaching 59%

Energy-Efficient Software-Defined AWGR-Based PON Data Center Network

In this paper, we present our results on tackling the oversubscription issue in the inter-cell communication in the Arrayed Waveguide PON based data center architecture proposed in our recent work. We enhance the bandwidth allocation by introducing 2-tiers of AWGRs to facilitate multipath routing and energy-efficient utilisation of resources. We also employ a centralized Software Defined Network (SDN) control and management system to coordinate and arbitrate the channel access for communication through the OLT links with PONs via wavelength reconfiguration and energy-efficient grooming. A benchmarking study between the proposed SDN architecture against the decentralized conventional design shows that with the SDN enabled architecture, the power consumption can be decreased by up to 90% for typical average data rates while maintaining zero blocking

TDM/WDM over AWGR Based Passive Optical Network Data Centre Architecture

Passive Optical Data Centre Networks have been developed due to the performance limitations in current data centres to provide high performance within data centre networks. An AWGR based passive optical network data centre architecture is evaluated using a TDM/WDM multiple access technique to provision the flow of traffic among the network efficiently. A Mixed Integer Linear Programming model is developed to optimise resource allocation in the architecture. Using WDM-TDM as a multiple access technique helps in solving issues such as oversubscription and congestion by allowing servers to make simultaneous transmissions of packets in different time slots. The results show that the provisioning / allocation of resource within the architecture is improved with improvements of up to 75% in resource utilisation

Visible Light Optical Data Centre Links

Providing high data rates is one of the big concerns in visible light communication (VLC) systems. This paper introduces a data centre design that use a VLC system for downlink communication. In this work, RYGB laser diodes (LD) are used as transmitters to obtain a high modulation bandwidth. Three types of receivers, wide field of view receiver (WFOVR), 3 branches angle diversity receiver (ADR) and 50 pixels imaging receiver (ImR) are used to examine delay spread and SNR. The proposed system achieved data rates up to 14.2 Gbps using simple on-off-keying (OOK) modulation

WDM NOMA VLC Systems

Wavelength division multiplexing (WDM) and non-orthogonal multiple access (NOMA) are employed in a visible light communication (VLC) system to increase the capacity of the system. The system is evaluated using two different scenarios focusing on power and data rate, where the first scenario is based on fair power allocation while the second scenario provides equal power allocation. Data rate variation is evaluated as a function of the users positioning and mobility. In both scenarios the proposed NOMA-WDM system achieved higher data rate NOMA system

Experimental Evaluation of Passive Optical Network Based Data Centre Architecture

Passive optical networks (PON) technology is increasingly becoming an attractive solution in modern data centres as it provides energy efficient, high capacity, low cost, scalable and flexible connectivity. In this paper we report the implementation of a PON based data centre architecture that provides high resilience and high speed interconnections by providing alternative communication routes between servers in different racks. Each rack is divided into several groups of servers and connects to other racks and the Optical Line Terminal (OLT) through a set of server that acts as relay servers. We implement the switching and routing functionalities within servers using 4×10GE Xilinx NetFPGA, and demonstrate end-to-end communication using IP cameras live video streaming over up to 100 km optical connections through WDM nodes and the PON network

NOMA Visible Light Communication System with Angle Diversity Receivers

In this paper, a non-orthogonal multiple access (NOMA) visible light communication (VLC) system is investigated. The system uses angle diversity receivers (ADRs) to provide high data rates. The ADR has 4 branches, each directed to a different direction. An 8m x 4m sized room is modelled to study the resource allocation to users according to their channel conditions to maximize the data rate. The results show that using ADRs improves the data rate by an average of 35% compared to a system using wide FOV receivers

Experimental Evaluation of Server Centric Passive Optical Network Based Data Centre Architecture

Passive optical networks (PON) technology has recently been proposed as a solution for scalability, energy efficiency, high capacity, low cost, flexibility and oversubscription issues in data centres. This paper experimentally demonstrates and discusses the implementation of a server centric PON based data centre architecture with high speed and reliability. The architecture is set up using a set of servers grouped into racks directly connected together and to the Optical Line Terminal (OLT) through gateway servers. The switching and routing functionalities have been embedded into servers using 4x10GE Xilinx NetFPGA. Flow continuity has been observed through live video streaming using IP cameras transmitting over up to 110 km optical connections through WDM nodes and the PON network