What sort of antennas are used in GSM communication?

What sort of Antennas are used in GSM communication....... can anyone provide any docs.. abt GSM antennas.

you can refer to vendors of antenna, for example Kathrein
www.kathrein.de

Kathrein uses for their base station antennas almost dipoles
in different orientations

regards

Look here:
Compact and Broadband Microstrip Antennas - KIN-LU WONG
Planar Antennas For Wireless Application - KIN-LU WONG
Try to find "Planar antenna.pdf" and "compact and broadbadn microstrip antenna.pdf"...