[1] Czech Tech Univ, Dept Electromagnet Field, Fac Elect Engn, CR-16635 Prague, Czech Republic
[2] Ranplan Wireless Network Design, Luton, Beds, England
[3] British Univ Dubai, Fac Engn & IT, Dubai, U Arab Emirates
[4] Univ Sheffield, Dept Elect & Elect Engn, Sheffield S1 3JD, S Yorkshire, England