Transcript Optical Packet/Burst Switching

Fast moving high bit rate users and terminals
Filip De Greve, Bart Lannoo, Tom Van Leeuwen, Frederic Van Quickenborne,
Didier Colle, Filip De Turck, Ingrid Moerman, Mario Pickavet, Bart Dhoedt,
Piet Demeester
When today’s commuters in the train or in a
car want to access the Internet, they see
themselves restricted to simple web surfing
or e-mail. Interactive multimedia services,
like online gaming or video conferencing
remain unavailable to them.
In the core network, different
solutions are possible: we can
choose a fully meshed network
consisting of IP routers or we could
consider a cheaper solution with
Ethernet switches. In this research,
we consider Ethernet as the most
appropriate choice for the core
network
because
of
different
reasons:
cost
effectiveness,
simplicity and bandwidth flexibility.
However,
the
deployment
of
Ethernet in core networks faces
problems such as low resource
utilization and large recovery times
after changes in the network
topology or in the traffic demand.
Nowadays, a lot of multimedia
applications are taken for granted
in fixed networks.
These applications require a high
level of Quality of Service (QoS) and
generally are characterized by high
bandwidth
requirements.
The
challenge future and current telecom
operators are facing is to examine
how this quality and bandwidth can
also be provided in wireless cellular
networks.
Therefore we will develop
and evaluate new protocols
and algorithms to address
these issues. This work is
situated in the current
research to extend the
Ethernet standard towards a
true transport technology for
core networks.
Today, organizations like IEEE and
3GPP are establishing specifications
for new wireless technologies which
have to meet the bandwidth
requirements of tomorrow (e.g.
UMTS and IEEE802.11g).
The validation of the developed
protocols and algorithms will be
done in a test bed environment,
existing of Click Modular Routers.
Unfortunately, the fast mobile user,
e.g. in the car or on the train, seems
always to be kept in the dark: the
faster they move, the more their
available
bandwidth
decreases.
Current
wireless
network
technologies are not capable to meet
the demand for high bandwidth at
high user velocity.
Along the rail track, a high data rate is
required in an extremely limited area. An
efficient re-utilization of the frequency
spectrum in combination with high radio
frequencies (e.g. 60 GHz) seems to be very
attractive. As a consequence, small cells
(micro- or pico-cells) will form an essential
part of the network, and this also means that
a lot of antennas have to be installed along
the railway.
In densely populated areas, such as cities
and business centers, there is an
evolution towards smaller cell sizes in
order to be able to satisfy the demand for
high bandwidth.
This however, results in a high handover
frequency (a handover typically every
few seconds) when the users move at
vehicular speeds.
To keep the whole
implementation
cost
efficient, we will make
use of Radio-over-Fiber
(RoF) technology. The
goal is to transfer
complicated signal processing functions from
the Remote Antenna
Units (RAUs) to a
Centralized
Control
Station.
Mobile
users
usually behave
in a more or less
predictable way,
e.g. cars driving
on a highway or
in a city.
There does not
yet
exist
a
handoff protocol
for fast mobile
users in small
cell
sized
access
networks.
Just like in the car scenario, fast moving users together with
small cells result in a lot of cumbersome handovers. In the train
scenario, we can make use of the advantage that all users move
at the same speed. This leads to the use of moveable cells.
Moveable Cells
Our goal is to make
interactive high bandwidth
multimedia
applications
possible in the car.
Therefore we are developing a
dedicated intelligent handoff
routing protocol taking into
account the knowledge of the
position and the trajectory of the
vehicle and the topology of the
access network.
Instead of having the train
moving along a fixed repeated
cell pattern, one might also
consider a cell pattern that
moves together with the train
and thus avoiding (most of) the
handovers.
In this way, it becomes
possible for commuters
to access the Internet
and game on-line on
the train.
This moveable cell concept will be realized by reconfiguring the
optical feeder netwerk (which makes use of RoF).
Department of Information Technology (INTEC) – Broadband Communication Networks (IBCN)