1. James Watt School of Engineering, University of Glasgow, Glasgow, U.K.
2. The Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
3. Electronics Engineering Department, University of Rome ''Tor Vergata'', Rome, Italy
4. Department of Electrical and Computer Engineering, Iowa State University, Ames, IA, USA
5. Department of Computer Engineering, Universitat Politècnica de València, Valencia, Spain
6. Electrical and Space Engineering, Department of Computer Science, LuleåUniversity of Technology, Luleå, Sweden
7. Department of Electrical and Electronics Engineering, University of Strathclyde, Glasgow, U.K.
8. School of Electrical and Information Engineering, University of the Witwatersrand at Johannesburg, Johannesburg, South Africa
9. National Institute of Telecommunications, Inatel, Santa Rita do Sapucaí, Brazil