Coexistence of 4th Generation Wireless Networks in Unlicensed Frequency Bands
Short Description
The goal of this work is to evaluate and extend existing methods for IEEE 802.16 (WiMAX) coexistence. Protocols allowing systems to meet own QoS demands while allowing other coexisting systems to meet theirs should be created.
Contents
Today we have two
kinds of wireless networks. On the one hand we have the cellular networks.
Characteristic for those is high network coverage and operation in licensed
frequency bands. Unfortunately there is a shortage of spectrum licenses. For
example operators in Germany had to spent about 50 million Euro for licenses
for 3. generation (UMTS) wireless systems.
On the other side
there are systems operating in free, unlicensed spectrum. Best know systems of
this kind are IEEE 802.11 (WLAN) and cordless phones (DECT). As long as there
are enough resources those systems operate sufficiently. But severe performance
degradation occurs once there are too many close by systems causing high
traffic. Nowadays its not unusual to sense 20 WLAN Access Points or more in an
apartment. The results are low throughput, high delays and frequent connection
breakdowns. It is impossible to provide sufficient quality of service (QoS) in
such an environment.
Mobile radio networks
of the next, the 4th generation, should be able to operate in
unlicensed spectrum to satisfy increasing traffic demands without purchase of
new, expensive spectrum licenses. This only makes sense if systems are able to
coexist in a way guaranteeing a minimal quality of service. Nobody wants his
phone call to be interrupted just because his neighbor starts to stream a
movie.
The
goal of this work is to evaluate and extend existing methods for IEEE 802.16 (WiMAX)
coexistence. Protocols allowing systems to meet own QoS demands while allowing
other coexisting systems to meet theirs should be created.
Contents of the Diploma-/Masterthesis shall be the
comparison of results of existing mathematic models to simulation results.
Assumptions in the simulator should be validated and adjusted if required to
model reality more accurate. The mathematic models should be extended to
increase the level of detail. The exact details are up to student and based on
his interests and previous knowledge.
Previous Knowledge of the C++ programming language should be
present since it is required to use and extend the openWNS simulator. Basic
knowledge about mobile radio networks should be present.
We offer a modern working environment in a friendly team
of assistants and students. Additionally we offer excellent contacts to
enterprises and industry through our alumni society (www.comnets.rwth-aachen.de/~friends). Feel free to
contact me by mail or just come by!
Last modified: 23-06-09
