In the first two years of this period some extraordinary problems had
to be solved: After the appointment of the chair at Aachen, I was
obliged to keep the chair of Data Processing Techniques at
FernUniversity of Hagen running. This duty still had to be served
until a successor was appointed in autumn
1992. The name of the Aachen chair ("`Allgemeine Elektrotechnik und
Datenfernverarbeitung"') was changed to Communications Networks
("`Kommunikationsnetze"') as the old label did no longer describe
activities in teaching and research, which are now mainly directed to
computer science and communications techniques.
Already in 1990 my predecessor Professor F. Schreiber had started
to substitute the 12 year old large computer base by introducing
SUN workstations, but this process was in an early stage. Further,
the staff had to be increased to serve new duties in extended
and new research areas, which are mainly supported by third
parties. The biggest problem was to increase the office capacity
to house the new staff members, since neither office space nor
money to establish it was available from the university.
As problems have to be solved we started to act: The old computer base
was given away to other organizations to serve as spare parts; the
large air-conditioning system was closed down and the central computer
room, freed by this action, was divided into a set of office rooms to
accommodate additional research staff. The SUN workstation pool was
substantially enlarged and connected to a cluster of MicroVAX
computers and workstations moved from Hagen to Aachen.
These extensions of staff and equipment had mainly become possible
because of the support from Industry, the German Research Council, the
Ministry of Economics and Technology of North-Rhine Westfalia, the
German Ministry of Research and Technology (BMFT) and the Commission
of the European Communities (CEC). In parallel, all lectures were set
up anew and the staff of the chair systematically extended its presence in
(inter)national committees and congresses.
I am very much obliged to Professor Schreiber for having well
scheduled the promotion dates of most of his research assistants to
ease handover of the chair and for having established properly working
internal structures to handle the daily work. It helped to familiarize
and get things under control.
The support of the university administration during the startup
phase is appreciated very much. At the end of the first two years, two
thirds of the scientific staff were already externally funded by research
grants.
During the following two years (1992 - 1994),
a consolidation of the personnel growth of COMNETS was reached,
establishing it as a significant part of the Faculty for
Electrical and Electronics Engineering, in both student
education and research;
the focus in our research activities on wireless and mobile
communications became more visible than before and is now documented
by a large number of ongoing projects, in co-operation with industry
partners all over Europe.
One of our observations was that students, who worked with us for
their diploma thesis, or had taken our courses in the main studies,
had little problems finding their first employment, which in these
days was not guaranteed.
Another observation was that, due to continuous and substantial
funding of COMNETS by third parties, we were able to supplement the
chair's labs with a sufficient number of state-of-the-art
workstations, providing the necessary computing power for extensive
performance studies.
It is worth mentioning that the budget received from the federal state
of Nordrhein-Westfalen to renew the chair's technical equipment has
remained on the same absolute level for years, being in fact a
reduction. Moreover, we were severely affected in 1993 by an
expenditure stop and withdrawal of unspent money by the federal state,
applied to a budget reserved to complement (by 50%) an expected
but not assigned extraordinary resource allocation from the state to upgrade
the students computer pool.
In addition to the resource limitations, we were confronted with a
very high load of students, which in some age-classes amounts to twice
the normal number of students. This situation was by no means
outbalanced by the small amount of overload dependent money allocation
per year, which in total is equivalent to about the yearly costs of
one research assistant, i.e. 5% of the chair's total budget. We were
forced by this situation to heavily rely on our personnel funded from
third parties to be able to fulfill our duties in student education.
During the last two years (1994-1996),
studies of fixed network related problems have been extended,
new services were proposed and the performance analysed, e.g. of
ATM-multiplexers and of value added services based on the
Intelligent Network;
we reached a status, where we now have available all the
existing and proposed mobile radio systems in Europe as detailed
simulators, enabling us to propose well founded improvements to the
various ETSI standardization committees;
the ``first generation'' of Ph.D. students finished their
theses and left the chair to take over responsibilities in other
organizations (the related work is referred to in section
5.1 on page ).
The high load of students continued, which in some age-classes
amounts to twice the normal number of students. One consequence of
this was that we had to supervise more than 60 diploma theses per year
at the chair, a quite heavy load which - on the other side - helped a
lot to develop our tool basis represented by CASE tools for formal
specifications, stochastic simulation and detailed modeling of all
recently introduced or forthcoming mobile radio systems in Europe. We
have been forced to rely on our scientific staff funded from third
parties to be able to fulfill our duties in student education (see
2 on page ). I
would like to thank here all of the chair's Ph.D.-students who
contributed so much to shoulder this heavy load phase, which now is
expected to reach normalization soon.
In parallel to this, I served to the faculty as a vice dean and
contributed to a number of subcommittees supporting the faculty
committee.
Due to the application oriented research work and the broad acceptance
of our scientific results by the telecommunications industry, we are
now in a situation, where 80% of our research staff is funded by
third parties with a tendency to further increase.
This report dedicates to each project a separate section, where the
contributing research assistants have summarized the objectives,
technical approach and results of their ongoing work. Although these
projects in most cases have been initiated and are closely supervised
by myself and/or the group leaders at the chair, we have decided not
to appear by name on top of the project work descriptions. Quick
readers might prefer to get an overview by reading section
3.1.1, where all our research fields and ongoing projects
are listed together.
