Photonic Network Communications, 5:2, 177±187, 2003
# 2003 Kluwer Academic Publishers. Manufactured in The Netherlands.
In-House Networks Using Multimode Polymer Optical Fiber for
Broadband Wireless Services
Ton Koonen, Anthony Ng'oma, Peter Smulders, Henrie van den Boom, Idelfonso Tafur Monroy, Giok-Djan Khoe
COBRA Institute, Eindhoven University of Technology, P.O. Box 513, NL 5600 MB Eindhoven, The Netherlands
Received May 24, 2002; Revised August 21, 2002; Accepted August 23, 2002
Abstract. A novel system concept is presented to transport microwave signals over an in-house multimode graded-index polymer optical ®ber
network, in order to feed the radio access points in high-capacity wireless LANs. By employing optical frequency multiplying, the network's
intrinsically limited bandwidth is overcome. The feasibility of this concept to carry data at several hundreds of Mbit/s speed for various
microwave signal formats at carrier frequencies in the tens of GHz range is shown. The concept enables cost-effective system implementation,
and easy upgrading by offering data signal transparency. It can readily be integrated with other system technologies such as wired Gigabit
Ethernet in a single multi-service in-house polymer optical ®ber network.
Keywords: in-house networks, polymer optical ®ber, optical frequency multiplying, broadband wireless services
Silica single-mode optical ®ber has already estab-
lished an undisputable position in core
telecommunication networks and in metropolitan
area networks, reaching Tbit/s throughputs. As a
next step, it is intruding the capillaries of the network,
the access lines. When moving towards the end user,
however, and penetrating his residential area, the
costs of installing and maintaining the ®ber network
become ever more important. Clear advantages are
offered by deploying polymer optical ®ber (POF): its
large core diameter considerably eases coupling and
splicing, and its ductility and ¯exibility simpli®es
installation in often less accessible customer loca-
However, although considerable improvements
have been made recently, the attenuation of POF is
still orders of magnitude higher than that of silica
single-mode ®ber. As it guides a huge number of
modes, the dispersion of POF is also much larger.
State-of-the-art per¯uorinated graded-index POF
(GIPOF) has losses below 20 dB/km at 1300 nm
(and 5 30 dB/km at 800 nm), and bandwidth length
products of around 1 GHz ? km. Therefore, POF
systems still have limited bandwidth and reach. For
short links such as in in-house networks, however,
high transport capacities have been achieved. Single-
wavelength systems have reached 11 Gbit/s over
100 m of GIPOF , and recently, a single-
wavelength GIPOF system carrying a Gigabit
Ethernet signal (1.25 Gbit/s) over almost 1 km
GIPOF has been experimentally demonstrated .
Wavelength multiplexing and novel approaches such
as mode group diversity multiplexing offer further
opportunities to extend the capacity of GIPOF
networks for digital data transport .
Wireless LANs are taking a rapidly evolving
market share of in-house broadband communications,
in particular in business and academic environments.
In order to provide high bit rates to the users, high
carrier frequencies and small radio cells are required.
Current wireless LAN products operate in the ISM
band (2.4 GHz), and offer transport capacities of
11 Mbit/s per carrier frequency, following the IEEE
802.11bstandard. IEEE 802.11a systems can carry up
to 54 Mbit/s per carrier in the 5.2 GHz band .
Systems offering more than 100 Mbit/s will require
carrier frequencies beyond 10 GHz; 60 GHz systems
are under investigation .
When the data rates and the carrier frequencies
increase, the radio cells that can be served become
smaller. Thus the number of antennas needed to cover
for instance an of®ce building grows, requiring a more