Speaker
Dr
Andrea Manara
(ITU-BR)
Description
The Radiocommunication Bureau of the ITU (ITU-BR) managed
the preparation and the conduct of the ITU Regional Radio
Conference RRC06 to establish a new frequency plan for the
introduction of digital broadcasting (band III and IV/V) in
Europe, Africa, Arab States and former-USSR States. During
the 5 weeks of the RRC06 Conference (15 May to 16 June 2006)
delegations from 119 Member States negotiated the frequency
plan.
The frequency plan was established in an iterative way.
During week time at the RRC06 administrations negotiated and
submitted their broadcasting requirements to the ITU-BR and
the associated results of negotiation (sometime in terms of
several million records). The ITU/BR carried out over the
weekend, substantive validation and processing activities
and conducted all the calculations (analysis and synthesis)
that resulted in assigning specific frequencies for the
draft plan. The result of the calculations was distributed
to delegations at the beginning of the subsequent week and
served as input for the next round of negotiations, with the
last iteration constituting the basis for the final
frequency plan. In addition, partial calculations were
performed for parts of the planning area in between two
global iterations (for the entire planning area).
For obtaining optimum planning of the available frequency
spectrum, two different software processes have been
developed by the European Broadcasting Union and they have
been run in sequence at the Conference by ITU/BR:
compatibility assessment and plan synthesis. The
compatibility assessment (which was very CPU demanding and
adapted to run on a distributed infrastructure) calculated
the interference between digital requirements, analogue
broadcasting and other services stations. The plan synthesis
assigned channels to requirements which could share the same
channel.
The limited time to perform the calculation called for the
optimization of the process. The turnaround time to provide
a new set of results was a critical factor for the success
of the Conference. The EGEE grid greatly enhanced the ITU-BR
available resources, constituted by a 100 PCs client-server
distributed system developed within the ITU-BR.
The compatibility assessment consisted in running a large
number of jobs (some tens of thousands). Each job is
basically the same application running on different datasets
representing the parameters of radio-stations. One should
note that the execution time varied by more than 3 orders of
magnitudes (the majority of jobs needed only few seconds but
few jobs required many hours) depending on the input
parameters and could not be completely predicted. To cope
with this situation we decided to use a client-server system
called DIANE that allows run-time load balancing, access to
heterogeneous resources (Grid and local cluster at the same
time) and a robust infrastructure to cope with run-time
problems. In the DIANE terminology, a job is defined as a
“task”. DIANE allowed us to use in the most effective way
the available resources since in this system each available
worker nodes asks for the next task: while a long task will
“block” a node, in the mean time the short tasks (the large
majority) will flow through the other nodes.
We demonstrated to be able to perform the required
calculations on the EGEE/LCG infrastructure during
feasibility tests performed in November 2006 and we used
these techniques during the Conference in very close
collaboration with CERN. We were also able to integrate the
EGEE infrastructure with the ITU-BR distributed system at
the monitoring level, via the Caltech-developed product
MonALISA.
The EGEE infrastructure did not only enable us to give the
adequate support for an important international event but,
in addition, the substantial speed-up observed opened the
possibility to allow faster and more detailed studies during
the Conference. The technical improvement gave the
possibility to provide a better service and technical data
to the Conference’s delegates.
Our set up was well suited for this application. The
possibility to access resources from the grid and corporate
resources (which we have not exploiting) is very appealing
and should be interesting for other users. The possibility
to describe and execute more complex workflow (presently we
are using the system to execute independent tasks in
parallel) could increase the interest for the tools we have
been using.
Author
Dr
Andrea Manara
(ITU-BR)
Co-authors
Adrian Muraru
(CERN)
David Botha
(ITU-BR)
Jakub Moscicki
(CERN)
Massimo Lamanna
(CERN)
Miroslav Cosic
(ITU-BR)
Patricia Mendez-Lorenzo
(CERN)