> On Sun, Oct 12, 2008 at 10:10 AM, Keith Lofstrom <[EMAIL PROTECTED]> wrote: >> How about the Max lines? Are there enough Skypilots to cover the >> stations, and perhaps be placed along the routes so that the 5.8GHz >> backhaul could connect them? More ambitiously, could something be >> added to the Max cars so that wifi was usable in them, and roaming >> was supported, so people could use wifi while they travelled?
> "Michael" == Michael Weinberg <[EMAIL PROTECTED]> writes: > As I calculate it, there are enough SkyPilots to cover 50-64 miles of > track (200-250 ft coverage radius per radio). Currently there are 44 > miles of track, but the new lines probably add considerably to that. > > I think the issues would be: > > a) Backhaul. The mesh is only going to support a few hops before > you'll need to inject new bandwidth. I would imagine that setting up > all the backhaul along the tracks is a larger hurdle than acquiring > wireless gear. Keith replies: I was needlessly confusing with my first posting. There are really two needs here: 1) wireless to the stations, and 2) wireless to the trains. Both would be nice. For (1) I was assuming the SkyPilots would be serving stations, and sometimes connecting to neighbors. The connection to the cloud would occur at many points along the lines, but not at every station for every Skypilot. At $3/foot for an above-ground fiber trunk, 44 miles of track would cost about $1M for the fiber alone, and probably as much again for station equipment. Fiber connection to existing providers (Verizon in Washington county and Gresham, Qwest?? in Portland) is likely to be much cheaper at most places along the route. Stations that are more than a few blocks from infrastructure might be better served by high-gain antennas to other directly-connected stations. The SkyPilots would not reach into trains, so (2) would require some kind of access point per car, and it would likely be an additional system that is distributed along the line. The (delayed) Westside rail system (WES) will have free wifi inside the cars, but I don't know how that will be provisioned. I assume Trimet will want to use similar technology throughout the system. > b) Reliable handoff between radios. In most instances, users traveling > on the train will only be connected to each radio for less than a > minute, and in some cases, only a few seconds. There's hardware that > claims to support that, but it hasn't been demonstrated (at least not > in Portland) that the SkyPilots can do that under real world > conditions. The SkyPilots should be at the stations (and possibly helping to bridge between some of the stations). Other provisioning talks to the moving trains, though the SkyPilots will be involved in handoffs between users waiting in station to users riding in cars. The SkyPilots might be talking to access points in trains stopped at the stations. Or not. As Michael points out, they probably cannot reach a train farther than a few hundred feet from a station. > Trimet does have an RFP out for wireless on a new line (not sure, off > the top of my head, which it is). The WES line is already allegedly provisioned for free wireless. The line was supposed to open last month, but the manufacturer of the trains (diesel powered double units, essentially articulated buses on rails) is in Chapter 12 and having trouble meeting obligations. At very minimum, wireless service in the stations would be a Good Thing, and much more likely to be used than wireless service to a park. So even if the moving trains did not have service, the main idea is that Trimet can still use SkyPilots for the stations. Financing is still a problem, though. Maintenance and connection to the cloud is not free. If TriMet pays for this and offers it "for free", then it either has to cut service somewhere else, or collect additional taxes, or raise ticket prices. These are all transfers from the transit-using poor without laptops to yuppies with laptops, and that is a terrible use of public services. If the advertising model doesn't do it, then perhaps the PTP "sponsored venue" approach might. There are two kinds of transit rail station - sterile transit-only stations like Portland and San Francisco, and stations with shops and diners and other commuter-related small businesses, like New York and Toronto. If there were coffee shops and convenience stores in the Max stations, they might be willing to sponsor some of the connectivity so that customers stay around. However, there are three major problems with PTP-style "shop sponsored" access. First, it may be years before most stations get shops, and TriMet would be carrying the load until then. Second, some stations will never attract shops and sponsors. Third, and most problematic, is that the city of Portland is actively hostile to at least some shops near transit - look at what they did to Peterson's newsstand near the 10th and Morrison Max stop. So wherever the SkyPilots go, they will cost money, both initially and long term, and somehow that cost should be borne by the users. It is unethical to extract it from the public at large, because that is moving resources from non-users to users, who tend to be better-off-than-average already. Tri-Met has a structure in place that can extract revenue from the users without taking it from the non-users, and the user benefits would far exceed the costs of running the system - it could be offered at low (though not zero) prices. That may be true of other uses for the SkyPilots, but I don't know what they are. It would be interesting to invite TriMet to a PTP monthly, to learn about their plans for WES. Perhaps working together, we could come up with some good ideas. TriMet could benefit from PTP expertise. Keith -- Keith Lofstrom [EMAIL PROTECTED] Voice (503)-520-1993 KLIC --- Keith Lofstrom Integrated Circuits --- "Your Ideas in Silicon" Design Contracting in Bipolar and CMOS - Analog, Digital, and Scan ICs --~--~---------~--~----~------------~-------~--~----~ The Personal Telco Project - http://www.personaltelco.net/ Donate to PTP: http://www.personaltelco.net/donate Archives: http://news.gmane.org/gmane.network.wireless.portland.general/ Etiquette: http://www.personaltelco.net/index.cgi/MailingListEtiquette List information: http://lists.personaltelco.net To post to this group, send email to [email protected] To unsubscribe from this group, send email to [EMAIL PROTECTED] -~----------~----~----~----~------~----~------~--~---
