COMBINED MODULATION FORMATS FOR IP OVER WDM NETWORKS
SUPPORTED BY GMPLS1
Sulur(1), Ton Koonen(2), Idelfonso Tafur Monroy(3), Huug de Waardt(4)
(1) COBRA Research Institute, Eindhoven University of Technology, The Netherlands, E-mail: sulur@tue.nl
(2) As (1) above, but E-mail: A.M.J.Koonen@tue.nl
(3) As (1) above, but E-mail: I.Tafur@tue.nl
(4) As (1) above, but E-mail: h.d.waardt@tue.nl
ABSTRACT
GMPLS (generalized multiprotocol label switching) for supporting IP over WDM networks provides quick and efficient
forwarding of IP packets because it uses label swapping as a single forwarding algorithm, thus yielding low latency and
enabling scaling to terabit rates. Combined ASK/FSK or ASK/DPSK modulation format for payload/label is proposed
for labeling IP over WDM networks supported by GMPLS. In this approach, the optical label swapping preserves the
optical transparency of the payload that is required for all-optical packet switching networks. Simulation results show
that a combined ASK/FSK modulation format is easier to implement and it tolerates a much larger laser linewidth than
the combined ASK/DPSK modulation format, but also requires more careful fiber dispersion compensation in order to
reduce the impact of the phase-to-intensity conversion.
1. INTRODUCTION
Internet traffic is growing fast and the Internet protocol (IP) framework is becoming the dominant form of data
transport. IP networks need to provide high speed (Terabit/s), large capacity, good performance and fast packet
forwarding rates (implying low latency). Up to 50% of IP traffic consists of packets smaller than 522 bytes and 50% of
these packets are in the 40-44 bytes range. Therefore, new low latency packet forwarding and routing technologies are
required [1].
Optical switches/optical cross connects and WDM (wavelength division multiplexing) devices that enable to
deploy the huge bandwidth offered by the optical fiber are commercially available. Therefore, in order to simplify the
network layers, transportin