The problem I have with all Citywdie WiFi projects is the so-called "Digital Divide". The projects assume all people have access to a wirless laptop. I believe that San Francisco's WiFi project should have hybrid BPL layer as part of the project. I just got a job at Motorola this year and they have an excellent backhaul solution that works with their hybrid BPL solution. The backhaul works with any 802.11 point of presence. The best combo is a multiple layer of wirless backhaul + hybrid wireless BPL + WiFi hotspot. The majority of stuggling residents in poorer neighborhoods certainly don't have wireless laptops but some do have personal desktop computers. Just visit the local S.F. libraries or Kinkos and you'll get a better idea of who needs real access. WiFi is part of the answer. My idea of the Backhaul + Hybrid BPL + WiFi is the better approach.
Felix Lopez
Bay Area Resident

[Editor's note: I don't disagree with the need for wired backhaul of some kind (whether BPL or otherwise), but I think you're falling into the trap of reading the reporting on SF's plan. All the municipal wireless plans that I've read include the requirement or option for CPEs (consumer premises equipment) that would be a Wi-Fi to Ethernet adapter. A DSL or cable modem is a CPE, for instance, and a Wi-Fi CPE can work just the same way, perhaps with a high-gain or directional external antenna. For residential use, there is no requirement or expectation of wireless laptops. For outdoor mobile use, naturally there is. --gf]

Editor, Tks for reply. Yes, Part c, Page 4 of RFP discusses Customer Premise Equipment (CPE). The only challenge is this requires a lot of footwork to each premise or residence to set up the antennae or interface. The wireless hybrid BPL platform uses an Access Point that can broadcast a signal to up to 10 homes at one time. If you have multiple Access Points then you can blanket a whole neighborhood and combine with the WiFi hotspot for denser areas. In my hybrid approach, its is full flavor. With hybrid BPL, The resident needs to only plub in a HomePlug alliance compatible modem that has an Ethernet connection and "wa la". The infrasture is more robust and less maintenence over time.

Here is what the text says from the RFP:
"Indoor, Perimeter Room coverage for the ground and second floors of a building shall be
provided for Basic and Premium Services for a minimum of 90% of all residential and
commercial buildings throughout the City. A building is assumed covered under this
Specification if a device located in each Perimeter Room on the ground and second floor of the building can access the Network at the provisioned service level. This coverage requirement may be met by using a Wi-Fi interface built into a user�s device, a signal amplifier, a high-gain antenna and/or a dedicated Wi-Fi bridge or other type of CPE." (that is a lot of walking around and pushes up the cost)

[Editor's note: CPEs will generally be self-install -- no walking around on the part of the service provider. If SF pursues a vendor-neutral approach similar to that in Philadelphia in which a wholesale model is encouraged, than service providers can differentiate themselves in how they offer CPEs ad what kind.

BPL isn't a bad idea, it's just poorly tested at this point since power companies appear reluctant to enter the business. The hybrid model you describe exists, but there are no extensive deployments of it, so it's unclear whether it would work better or worse than SF's RFP. It would almost certainly deliver much higher rates of speed, but it would also almost certainly involve much more expense and be owned by the power utility, which might choose to not offer wholesale access to other providers. It would also lack the mobility component that a citywide Wi-Fi network will have, although that could be built out in other ways.--gf]

Tks for reply. Once again, my thought ws to compliment the City WIFI and the CPE could be a hybrid BPL flavor along with other CPE technologies. In response to your point that "the power company would own" Not true. I know of thrid party ISPs that can install an provision a hybrid system such as WIFI plus hybrid BPL. The power companies have joint pole agreement process in place to allow third parties access to the poles. They do this all the time. Regarding your comment about testing. Not true. The ARRL (I'm a member) has already worked with hybrid BPL systems to insure works ok and FCC on this too. Also the local CPUC seeking more activity with hybrid systems. The Philadelphia WiFi project actually uses the Backhaul technology that I'm discussing. But you are correct that the CPE technology should be of customer choice. Once again the assumption is tha everyone has access to a Desktop PC or a wireless laptop. Spend time at a local SF Library or Kinkos and you will see differently.

[Editor's note: We're working from different assumptions here, but I appreciate your response on all this. I'm not referring to the ARRL (amateur radio) concerns. The fact that third parties exist doesn't mean power companies won't and don't own and control; they're sometimes partnering with third parties (as in Texas). The Philly project doesn't use BPL; it's going to use Motorola Canopy in unlicensed frequencies for point-to-multipoint. If you're being told they're using BPL, it's incorrect. EarthLink, Tropos, and Motorola all explained the Canopy decision to me. --gf]