A Kumar wrote in with the following update on the wireless licencing in India:
1. In the US, the FCC amended its Part 15 rules in year 1997 to make 300 Mhz of spectrum available for high speed wireless digital communication with un-licensed operation. This band called the U-NII ( Un-licensed National Information Infrastructure) band, provides spectrum at:
5.15 to 5.25 Ghz for indoor use, ( Lower band )
5.25 to 5.35 and ( Middle band )
5.725 to 5.825 for outdoor use. ( Upper band )
The peak transmitted power is limited to 23 dBm for indoor and 30 and 36 dBm ( 4 watts ) respectively for the middle and upper bands.
So, wireless operators ( WISP’s ) rolled-out large scale networks using this
spectrum, as it was free and no spectrum royalties payable and this did result in low cost products as these Radio’s were made in huge volumes thus resulting in
economies of scale.
2. In India though, these band are already used in some sensitive applications:
a. 5.15 to 5.25 Ghz for Aeronautical and Radio navigation
b. 5.25 to 5.35 Ghz by Earth exploration satellites, Space research
c. The upper band has been opened by WPC for use by ISP’s and other telecom operators for point to point as well as point to multi-point links.
Hence it is my view that 802.11a products could de-generate RF signals used for these applications, as you are aware ingenius RF Enginners in India, will rig out RF links spanning 10-12 KM’s with this so called indoor WLAN products in 5 Ghz by getting the chipset at < US $ 100 and pluging a high gain antenna of 18 – 24 dBm.
3. So, in hindsight India could opt of 802.11g standard , whenever the capacity of 802.11b is saturated as we can get 54 Mbps out of the same 2.4 Ghz spectrum used in 802.11b.
4. I also understand that in Germany and other europrean countries and Australia the 5 Ghz spectrum is used for similar RADAR applications and hence they may not approve of 802.11a standard.
Thanks for the update, Kumar. Very useful.