Kommunikationssysteme

Kommunikationssysteme

The laboratory is open to students and staff for research and teaching activities. It is split into a simulation lab and a network lab.

Location: 35390 Giessen , Wiesenstraße 14, G-building, Rooms G214 and G207, Tel: 0641-309-1926. 

Simulation Lab (G214):

• Mobile Communication: Radio Network Planning Tool A955
• Physical Layer Simulation with Matlab/Simulink (classroom licence)

Network Lab (G207):

• Protocol analysis (VoIP, Videoconferencing or streaming)
• WLAN planning and protocol analysis
• GSM/GPRS Drivetestsystem and indoor analysis 

Raum

G214 , G207

Personen

Simulation Lab (G214): Radio Network Planning with A955

The Simulation Lab is for computer-aided Network Planning of mobile radio networks. The following system technologies are currently supported:

• GSM and Microwave Links
• GPRS and EDGE
• UMTS (in preparation)

The infrastructure consists of 12 PC’s with Windows-NT and Linux dual-boot configuration, which serve as a platform for A955 (12 licences are available).

The Radio Network Planning Tool A955 of Alcatel is used for computer-aided Radio Network Designs. This tool is widely used in all major Alcatel projects worldwide.

With A955 it is possible to predict the Quality of Service at the air interface of a mobile radio network. After the Radio Base Stations have been set by the tool user, it is possible to predict the field strength taking into account the topography and morphology of the planning area. In A955, all relevant propagation models (e.g. 3D Ray Tracing) are implemented.

Some examples for possible predictions are: Maximum field strength, Carrier to Interferer Ratio, Coverage Probability or Traffic Predictions for circuit-switched and packet-switched services. Figure 1 shows, for example, the achievable bit rate in a GPRS network.

The tool is used for the lab work of the lecture mobile communication in order to extend the understanding of mobile system technologies, radio propagation and to have an insight on professional radio network planning methodologies.
 

Figure 1:Achievable bit rate in a GPRS network design

Figure 2: The Simulation Lab, Room G214

Figure 3: Steps of computer aided Radio Network Planning

Figure 4: Typical Network Lifecycle

Simulation Lab (G214): Physical Layer Simulation with Matlab/Simulink

For teaching purposes, a classroom licence of Matlab/Simulink including the Communication and Signal Processing Toolbox, is available. It is used for physical layer simulations. Students learn to work with Matlab/Simulink and to analyse the effect of various algorithms (modulation, channel coding etc.) on actual communication systems. For this purpose, they can develop and analyse their own models within lab exercises.

Figure 5: Simulink IEEE 802.11a WLAN Model developed by a student 
 
 

Network Lab (G207): Protocol Analysis

The Network Lab is used for Protocol Analysis and Quality of Service (QoS) Analysis of different network technologies.

Wired & Wireless LAN: Protocol Analysis :

Protocol Analyzers are used within the lab work of the lecture telecommunications in order to gain a better understanding of network protocols and their impact on network performance for different services.

Figure 6:IEEE 802.3 trace recorded with Ethereal

Figure 7: The H323 Protcol Stack

Network Lab (G207): GSM/GPRS Drive Test System and indoor measurements

The air interface measurement system ROMES of Rohde&Schwarz is used for air interface measurements within the lab work of the lecture mobile communications.

Measurements are performed indoors and outdoors to investigate radio propagation and the impact of link quality and traffic on system performance. The results of these investigations are valuable inputs for radio network planning and optimisation purposes.

 Network Lab (G207): Wireless LAN Analysis

Figure 9: Coverage analysis of a single WLAN Access Point at university campus