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

Abstract

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. WDM-TDM PON-BASED DATA CENTRE ARCHITECTUREIn this architecture each PON Cell contains two AWGRs as shown in Figure.1, to provision full interconnection between the 4 racks. Each rack contains 32 servers, using 4 different wavelengths. A 1: N AWGR connects the racks and the OLT. The network interface card of each server contains an array of photo detectors for wavelength detection and tuneable lasers for wavelength selection [11].Inter-rack communication is done through the direct AWGR link or through the OLT. The AWGR selects the wavelength for transmission according to the location of the destination server, and servers communicate according to an AWGR wavelength routing interconnection map. The availability of alternative routes provides multi-path routing and enhances load balancing at high traffic load [11].

Optimized Passive Optical Networks with Cascaded-AWGRs for Data Centers

“…A Fat-Tree topology [2] comprises three layers which are the core, aggregation and access layers. In Figure 2, an example is given of a Fat-Tree topology that includes k = 4 pods and each pod contain 2 = 2 ⁄ access switches and 2 = 2 ⁄ aggregation switches.…”

“…Current data centers have many limitations such as high cost, high latency, limited scalability, management complexity and low throughput [1], [2]. Therefore, it is becoming necessary to design new data center architectures that resolve these limitations.…”

Energy efficient passive optical data centre networks

“…Over the past few decades, there has been a growing trend towards the development of energy-efficient core and access communication networks 7, . Additionally, there is considerable attention dedicated to devising energy-efficient solutions for data centre designs, as evidenced by the research spanning these areas [39][40][41][42][43][44][45][46][47][48] . The work in this paper aims to reduce the power consumption of the commodity networking hardware used by introducing novel ways of interconnecting and manging servers, accelerators, storage and interfaces in small processing cells (cloudlets).…”