Hi Kiran,
The 3500's are rated as Indoor Access Points
Cisco Aironet® 3500i model
● Sleek design with internal antennas
● Ideal for carpeted offices
Cisco Aironet 3500e model
● Rugged metal housing and extended
operating temperature
● Ideal for factories, warehouses, and
other indoor industrial environments
● Versatile RF coverage with external
antennas
● UL 2043 plenum-rated for aboveceiling
installation options or
suspended from drop ceilings
http://www.cisco.com/en/US/prod/collateral/wireless/ps5678/ps10981/data_sheet_c78-594630.pdf
There are Outdoor enclosures from Terrawave
http://www.terra-wave.com/shop/80211n-mimo-enclosures-mimo-steel-enclosures-c-1_23_32.html
Cheers!
Rob
