The document discusses advancements in optical communication technologies to reduce the energy footprint of ICT, highlighting that the sector emits as much greenhouse gases as airlines. It presents strategies like all-optical packet switching and broadband fibre to the home, which significantly lower power consumption. Additionally, it advocates for the integration of wired and wireless networks to optimize resource utilization and enhance service delivery.

1. “Science meets IT”
- discussion
Ton Koonen
COBRA Institute, Eindhoven Univ. of Technology
a.m.j.koonen@tue.nl
Greening the Enterprise, Utrecht, Nov. 25, 2009
COBRA

2. Connected World
fibre
Global Network
•• long reach
long reach
•• high capacity
high capacity
Metropolitan/Regional
Area Optical Network •• fast packet
fast packet
switching
switching
Client/Access Cable modem SDH/
ISP
SONET •• variety of
Networks Networks
IP variety of
IP/ATM media +
media +
services
services
Cable TP FTTH FWA cellular •• personal
personal
In-home and •• mobility
mobility
Personal
Triple Play •• low power
low power
mobile •• low cost
Networks BAN low cost
WLAN sensor
Home / Enterprise In-/outdoor wireless
amjk
26-11-2009 PAGE 1
© a.m.j. koonen, Nov. 25, 2009 1

3. Energy footprint of ICT
E.g. Harvard scientists: “the whole ICT sector produces as much greenhouse gasses
as all airline companies together; 1000 Google searches consume as much
energy as driving 1 km with a car”
Reduction of energy footprint by Optical communication technologies
- optical multi-level signal transport:
put more bits into a single transmitted symbol
- all-optical packet switching:
avoid power-hungry electro-optical conversions in routers
- optical interconnects:
reduce crosstalk
- broadband fibre to the home* :
reduce 24/7 power consumption
* optical access by Gigabit PON consumes about 18x less energy per user than VDSL2
- radio over fibre:
bring the radio antenna closer to the user, reduce radiation power levels
- wired/wireless network integration:
use a single in-home network to carry wired and wireless services
amjk
© a.m.j. koonen, Nov. 25, 2009 2

4. Dynamic wavelength routing
in access networks
fibre
local
exchange
access network cells
hot spot
provides capacity-on-demand to cells,
optimises utilisation of network resources
[a.m.j. koonen, Proc. of the IEEE, May 2006] amjk
© a.m.j. koonen, Nov. 25, 2009 3

5. Radio over Fibre
To increase capacity:
Smaller cells less users/cell
Higher frequencies more BW available
Central
Controller
RG Simplified
antenna sites
Optical Fibre
Huge capacity
Energy efficient transmission
Light weight
Immune to electromagnetic
interference
→ Radio-over-Fibre
amjk
[courtesy Maria Garcia Larrode] 4
© a.m.j. koonen, Nov. 25, 2009

6. Today’s in-home networks
Twisted pair copper
Satellite dish/
lines: FWA dish
Telephone, fax, …
Coaxial copper lines:
(HD)TV
CATV, videorec, radio, … laptop
Mobile network
mobile
Cat-5 cables: (GSM, UMTS, …)
PC-s, routers, hubs, coax Cat-5 PC
printers, servers, …
Wireless LAN: O WiFi Tel.
Laptops, PDAｓ、… Optical Fibre network N router mp3
U CATV download
Infrared: Coax Cable network fax
TP print PDA
Twisted Pair network Tel.
remote control
TV/videorec/radio/…
amjk
© a.m.j. koonen, Nov. 25, 2009 5

7. Converged in-home network: with fibre
integrating wired &
wireless services:
less installation and
maintenance efforts optical
fibre
easier introduction and
webcam
upgrading of services
integration e.g. by WDM HDTV laptop
Mobile network PC
(GSM, UMTS, …) mobile
optical
fibre
VoIP
RG
Optical Fibre mp3 fax
coax network download print PDA
POF
converged in-home network on
SMF
Plastic Optical Fibre
amjk
© a.m.j. koonen, Nov. 25, 2009 6