Some cold water...
From Mark O'Leary
Monday, March 10, 2003
I admire the enthusiasm being displayed on this list, and have been an advocate of a community wireless solution for some time, but it is not quite as easy as has been suggested recently.
For example, suggested solutions are being based on rated bandwidth rather than 'real-world' throughput. An '11Mbs' 802.11b solution can *at best* provide around 6Mbs measured throughput, and that is shared between every user of that access point. A recent proposal suggested that 200+ users would split the costs. Assuming that APs are deployed on all 4 non-overlapping bands, thats up to 50 users per AP, which is only around 10kbps each. (similarly 802.11g rated at 54Mbs actually only provides about 20Mbs - and the price of that extra bandwidth is *vastly* reduced range). This 'back-of-envelope' calculation doesnt take into account the fact that those nearer the AP can grab larger slices of bandwidth at the expense of those further away. Nor has anyone mentioned security of a wireless network (at present, VPN is the only robust solution - and theres a trade-off of cost vs. making it accessible to a non-technical user).
The viable appraoch is, as has been discussed before, a mesh with a significant number of the mesh participants having an internet uplink - i.e. ADSL. We should not let BT off of the hook with regards to enabling our exchange. Let's concentrate our campaigning on getting BT to rethink their broadband embargo on us, and *then* take the ADSL/SDSL facility to the next level with an overlaid community WiFi system.