TANDEM - Ein extrem verbrauchsarmes, skalierbares, tandemprozessorbasiertes Funksystem für sensorische, aktuatorische und kennzeichnende Anwendungen

An extremly power-efficient, scalable, Tandem-processor-based radio system for sensing and actuation application

As part of the BMBF-funded TANDEM project, our research group is looking at integrating so-called diversity techniques into wireless sensor networks. Specifically, we are interested in:

• Network coding in wireless sensor networks
• Partial forwarding of only correctly received parts of a packet in order to prevent error propagation
• Integration of diversity techniques with energy-efficient MAC protocols and investigating its effect on energy consumption. This is desirable because the current MAC protocols for WSN's try to minimize the energy utilization by addressing issues such as efficient scheduling, idle listening and Overhearing. However these protocols do not take advantage of additional collaboration from distant nodes with relatively low SNR values but which can possibly participate in cooperative communication.

• Rana Azeem M. Khan, Holger Karl: "Multihop Performance of Cooperative Preamble Sampling MAC" (CPS-MAC) in Wireless Sensor Networks, Proc. 10th International conference on Ad Hoc and Wireless Networks (ADHOC-NOW 2011), July 2011.

• Rana Azeem M. Khan, Holger Karl: "Cooperative Communication to Improve Reliability and Efficient Neighborhood Wakeup in Wireless Sensor Networks" in Proc. 4th International Conference on Mobile Ubiquitous Computing (UBICOMM 2010), Oct 2010.

• T. Volkhausen, D. H. Woldegebreal, H. Karl: ''Improving Network Coded Cooperation by Soft Information", in Proc. IEEE International Workshop on Wireless Network Coding (WiNC2009), Jun. 2009. 

• S. Valentin, D. H. Woldegebreal, T. Volkhausen, H. Karl: "Combining for cooperative WLANs -- A reality check based on prototype measurements", in Proc. IEEE Workshop on Cooperative Mobile Networks (CoCoNET2), collocated with IEEE ICC, Jun. 2009. 

• S. Valentin, T. Volkhausen, F. Atay Onat, H. Yanikomeroglu, H. Karl: "Decoding-based channel estimation for selective cooperation diversityprotocols", in Proc. IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC), Sep. 2008. 

• Dereje H. Woldegebreal, S. Valentin, H. Karl: "Incremental Network Coding in Cooperative Transmission Wireless Networks", in Proc. IEEE Vehicular Technology Conf. (VTC-Fall), Sep. 2008. 

• D. Platz, Dereje H. Woldegebreal, H. Karl: "Random Network Coding in Wireless Sensor Networks: Energy Efficiency via Cross-Layer Approach'', in Proc. 10th IEEE ISSSTA 2008, August 2008. 

• S. Valentin, T. Volkhausen, F. Atay Onat, H. Yanikomeroglu, H. Karl: "Enabling partial forwarding by decoding-based one and two-stage selective cooperation'', in Proc. IEEE Cognitive and Cooperative Wireless Networks (CoCoNET) Workshop collocated with IEEE ICC, May 2008.

• Dereje H. Woldegebreal, H. Karl,"Network-Coding-based Cooperative Transmission, Wireless Sensor Networks: Diversity-Multiplexing tradeoff and Coverage Area Extension", in Proc. 5th European conference on Wireless Sensor Networks (EWSN), January 2008. Acceptance rate: 21%.

• Dereje H. Woldegebreal, S. Valentin, H. Karl: "Outage Probability Analysis of Cooperative Transmission Protocols without and with Network Coding: Inter-User Channels based Comparison", in Proc. 10th ACM/IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems (MSWiM), October 2007, Regular paper.