Valentin, S., Lichte, H. S., Warneke, D., Biermann, T., Funke, R., &; Karl, H. (2008). Mobile Cooperative WLANs - MAC and Transceiver Design, Prototyping, and Field Measurements. In 2008 IEEE 68th Vehicular Technology Conference. IEEE.https://doi.org/10.1109/vetecf.2008.350 

Valentin, S., Freitag, T., &; Karl, H. (2008). Integrating Multiuser Dynamic OFDMA into IEEE 802.11 WLANs - LLC/MAC Extensions and System Performance. In 2008 IEEE International Conference on Communications. IEEE.https://doi.org/10.1109/icc.2008.626 

Woldegebreal, D. H., &; Karl, H. (2008). Network-Coding-Based Cooperative Transmission in Wireless Sensor Networks: Diversity-Multiplexing Tradeoff and Coverage Area Extension. In Lecture Notes in Computer Science (pp. 141–155). Berlin, Heidelberg: Springer Berlin Heidelberg.https://doi.org/10.1007/978-3-540-77690-1_9 

H. Woldegebreal, D., &; Karl, H. (2008). Network-Coding-Based Cooperative Transmission in Wireless Sensor Networks: Diversity-Multiplexing Tradeoff and Coverage Area Extension. In Wireless Sensor Networks, 5th European Conference, EWSN 2008, Bologna, Italy, January 30-February 1, 2008, Proceedings (pp. 141--155).https://doi.org/10.1007/978-3-540-77690-1_9 

Valentin, S., Freitag, T., &; Karl, H. (2008). Integrating Multiuser Dynamic OFDMA into IEEE 802.11 WLANs - LLC/MAC Extensions and System Performance. In Proceedings of IEEE International Conference on Communications, ICC 2008, Beijing, China, 19-23 May 2008 (pp. 3328--3334).https://doi.org/10.1109/ICC.2008.626 

S. Lichte, H., Valentin, S., Karl, H., Aad, I., Loyola, L., &; Widmer, J. (2008). Design and Evaluation of a Routing-Informed Cooperative MAC Protocol for Ad Hoc Networks. In INFOCOM 2008. 27th IEEE International Conference on Computer Communications, Joint Conference of the IEEE Computer and Communications Societies, 13-18 April 2008, Phoenix, AZ, USA (pp. 1858--1866).https://doi.org/10.1109/INFOCOM.2008.249 

Valentin, S., S. Lichte, H., Karl, H., Aad, I., Loyola, L., &; Widmer, J. (2008). Opportunistic relaying vs. selective cooperation: analyzing the occurrence-conditioned outage capacity. In Proceedings of the 11th International Symposium on Modeling Analysis and Simulation of Wireless and Mobile Systems, MSWiM 2008, Vancouver, British Columbia, Canada, October 27-31, 2008 (pp. 193--202).https://doi.org/10.1145/1454503.1454539 

Valentin, S., Volkhausen, T., Atay Onat, F., Yanikomeroglu, H., &; Karl, H. (2008). Decoding-based channel estimation for selective cooperation diversity protocols. In Proceedings of the IEEE 19th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2008, 15-18 September 2008, Cannes, French Riviera, France (pp. 1--6).https://doi.org/10.1109/PIMRC.2008.4699545 

Valentin, S., S. Lichte, H., Warneke, D., Biermann, T., Funke, R., &; Karl, H. (2008). Mobile Cooperative WLANs - MAC and Transceiver Design, Prototyping, and Field Measurements. In Proceedings of the 68th IEEE Vehicular Technology Conference, VTC Fall 2008, 21-24 September 2008, Calgary, Alberta, Canada (pp. 1--5).https://doi.org/10.1109/VETECF.2008.350 

H. Woldegebreal, D., Valentin, S., &; Karl, H. (2008). Incremental Network Coding in Cooperative Transmission Wireless Networks. In Proceedings of the 68th IEEE Vehicular Technology Conference, VTC Fall 2008, 21-24 September 2008, Calgary, Alberta, Canada (pp. 1--5).https://doi.org/10.1109/VETECF.2008.346 

Platz, D., Woldegebreal, D. H., &; Karl, H. (2008). Random network coding in wireless sensor networks: Energy efficiency via cross-layer approach. In Spread Spectrum Techniques and Applications, 2008 IEEE 10th International Symposium on (pp. 654--660).

Valentin, S., Volkhausen, T., Onat, F. A., Yanikomeroglu, H., &; Karl, H. (2008). Enabling partial forwarding by decoding-based one and two-stage selective cooperation. In Communications Workshops, 2008. ICC Workshops’ 08. IEEE International Conference on (pp. 129--133).

Woldegebreal, D. H., &; Karl, H. (2007). Multiple-Access Relay Channel with Network Coding and Non-Ideal Source-Relay Channels. In 2007 4th International Symposium on Wireless Communication Systems. IEEE.https://doi.org/10.1109/iswcs.2007.4392437 

Karl, H. (2007). Optimizing sleeping intervals in preamble sampling MAC for WSNs. Bern / Switzerland: Communication in Distributed Systems (KiVS), 2007 ITG-GI Conference.

Festag, A., Karl, H., &; Wolisz, A. (2007). Investigation of multicast-based mobility support in all-IP cellular networks. Wireless Communications and Mobile Computing, (3), 319--339.https://doi.org/10.1002/wcm.328 

van der Stok, P., Karl, H., De Ambroggi, F., Decotignie, J., Siegemund, F., Lokhorst, K., &; Hellenschmidt, M. (2007). WASP - Wirelessly Accessible Sensor Populations: A Project Overview. In Constructing Ambient Intelligence - AmI 2007 Workshops Darmstadt, Germany, November 7-10, 2007 Revised Papers (pp. 426--429).https://doi.org/10.1007/978-3-540-85379-4_49 

H. Woldegebreal, D., Valentin, S., &; Karl, H. (2007). Outage probability analysis of cooperative transmission protocols without and with network coding: inter-user channels based comparison. In Proceedings of the 10th International Symposium on Modeling Analysis and Simulation of Wireless and Mobile Systems, MSWiM 2007, Chania, Crete Island, Greece, October 22-26, 2007 (pp. 36--44).https://doi.org/10.1145/1298126.1298136 

Valentin, S., von Malm, H., &; Karl, H. (2007). Traffic-Aware Asymmetric Cooperation Diversity for Media Streaming in Wireless Networks. In Proceedings of the IEEE 18th International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2007, 3-7 September 2007, Athens, Greece (pp. 1--6).https://doi.org/10.1109/PIMRC.2007.4394223 

S. Lichte, H., Valentin, S., Eitzen, F., Stege, M., Unger, C., &; Karl, H. (2007). Integrating multiuser dynamic OFDMA into IEEE 802.11a and prototyping it on a real-time software-defined radio testbed. In 3rd International ICST Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities, TridentCom 2007, Orlando, Florida, USA, May 21-23 2007 (pp. 1--9).https://doi.org/10.1109/TRIDENTCOM.2007.4444671 

Valentin, S., &; Karl, H. (2007). Effect of User Mobility in Coded Cooperative Systems with Joint Partner and Cooperation Level Selection. In IEEE Wireless Communications and Networking Conference, WCNC 2007, Hong Kong, China, 11-15 March, 2007 (pp. 896--901).https://doi.org/10.1109/WCNC.2007.170