Radio-over-Fibre access for sustainable Digital Cities

Abstract

Pervasive broadband access will transform cities to the net social, environmental and economic benefit of the e-City dweller as did the introduction of utility and transport network infrastructures. Yet without action, the quantity of greenhouse gas emissions attributable to the increasing energy consumption of access networks will become a serious threat to the environment. This paper introduces the vision of a 'sustainable Digital City' and then considers strategies to overcome economic and technical hurdles faced by engineers responsible for developing the information and communications technology (ICT) network infrastructure of a Digital City. In particular, ICT energy consumption, already an issue from an operating cost perspective, is responsible for 3 % of global energy consumption and is growing unsustainably. A grand challenge is to conceive of networks, systems and devices that together can cap wireless network energy consumption whilst accommodating growth in the number of subscribers and the bandwidth of services. This paper provides some first research directions to tackle this grand challenge. A distributed antenna system with radio frequency (RF) transport over an optical fibre (or optical wireless in benign environments) distribution network is identified as best suited to wireless access in cluttered urban environments expected in a Digital City from an energy consumption perspective. This is a similar architecture to Radio-over-Fibre which, for decades, has been synonymous with RF transport over analogue intensity-modulated direct detection optical links. However, it is suggested herein that digital coherent optical transport of RF holds greater promise than the orthodox approach. The composition of the wireless and optical channels is then linear, which eases the digital signal processing tasks and permits robust wireless protocols to be used end-to-end natively which offers gains in terms of capacity and energy efficiency. The arguments are supported by simulation studies of distributed antenna systems and digital coherent Radio-over-Fibre links.

Electro-optic up-conversion mixer amenable to photonic integration

“…Optical mixer implementation acquires even greater relevance in coherent optical RoF systems, where the transport of m-ary quadrature amplitude modulation provides technical and environmental advantages relative to the traditional analog RoF systems that make use of the intensity modulation and direct detection techniques [14]. To the best of the authors' knowledge, the electrooptic up-conversion of complex-modulated mm-waves has received little attention.…”

Proposta De Um Novo Algoritmo Qos-Aware Para O Escalonamento Downlink Lte-a Em Cenários De Tráfego Misto: Uma Comparação De Desempenho

“…The application of the IoT paradigm to an urban context is of particular interest nowadays, as it permits the adoption of the information and communications technology (ICT) solutions to be used in the management of public affairs, thus realizing the concept known as Smart City (Hall et al, 2013)environmental and economic benefit of the e-City dweller as did the introduction of utility and transport network infrastructures. Yet without action, the quantity of greenhouse gas emissions attributable to the increasing energy consumption of access networks will become a serious threat to the environment.…”

On-Chip Koch Fractal Antenna Array for 60 GHZ Ism Band Application

“…RoF links are often used in a point-to-point topology (Fernando, 2001;Hall et al, 2013;Hossen e Jang, 2009;Wiberg, 2008)environmental and economic benefit of the e-City dweller as did the introduction of utility and transport network infrastructures.…”