Today’s WLAN standards project data rates up to multiple Gbit/s. Often these rates can not be achieved outside the laboratory. Overlapping WLANs and dense networks with a high number of stations are reasons for lower effective rates. The established media access methodology Carrier Sense Multiple Access / Collsion Avoidance (CSMA/CA) limits the access to the medium to one single station. This medium sharing in the time domain leads to lower effective data rates for the users.
The current standard IEEE 802.11ax (High Efficiency) sets a goal of increasing the effective data rate for the user by a factor of four. Multiple measurements in the PHY and MAC area are defined, however without specifying the algorithms how to use it. Focus of our project‚ WLAN Resource Management‘ is research on effective algorithms to control key parameters like transmit power and modulation and coding schemes in today’s WLANs with a goal of optimal usage of the media. Optimal usage means using the media resources time, space and frequency in such a way, that high system data throughput is paired with station fairness.
Current research spans a wide area from analytical describtion of system efficiency over channel measurements using multi antenna systems to simulation of networks. One focus area is a better usage of the media resource space, either using multiple space time streams (MIMO) or parallel transmissions with controlled conditions of interference (spatial reuse). Precise models of the wireless channel are very important for such optimization tasks.
For channel measurements a lot of state of the art instruments are available. A modular 12-port 9 GHz Vector Network Analyzer and 2 Software Defined Radio Platforms USRP are complemented by multiple current spectrum analyzers and other instruments. Network simulation is done using Matlab WLAN Toolbox.