Survey
[1] Ertel1998
[2] Martin1999
Outdoor
[3] Klein1996
[4] Pedersen2000
[5] Kavak2000
[6] Cheon2001
[7] Algans2002
Microcell
[8] Dottling1997
Indoor-Outdoor
[9] Woodward1999
Indoor
[10] Spencer2000
[11] Zwick2002
Unified Models
[12] Tameh1997
[13] Fuhl1998