Connecting 2 Wifi Networks Via Cantenna

Apr 30, 2007 24 Replies
J

John Navas hath wroth:

I don't think satellite WiMAX is being proposed. WiMax is also not an answer to satellite capacity problems. Incidentally, the lower layers of the WiMax protocol are almost identical to DOCSIS as used on the CATV networks. So are some of the higher level management protocols. That was intentional to allow easy conversion of cable settop technology to wireless. I'll supply a suitable conspiracy theory when I think of one.

Nope, not yet. Don't worry, I'll tear it apart eventually.

Possibly. I really don't know because I haven't run the calculations. Which terrestrial service has 100:1 oversubscription of advertised bandwidth and I'll do the numbers? I don't have time to research all of them. Just pick one. If you pick cable, please pick a vendor because different cable vendors use different topologies and traffic mixes, which have a huge effect on available bandwidth.

That's odd. I'm seeing about the same number for my few satellite customers. Perhaps it's because the early adopters and complainers have all dropped out and are being replaced with more tolerant customer base. Kinda like cell phone service, where the customers have simply learned to tolerate garbled audio, lack of coverage, creative billing, and dropped calls. Also like compressed video, where the general deterioration of NTSC picture quality due to compression has only recently been alleviated by HD (high dollar) TV.

Compression and protocol technology is not going to do much for a

100:1 overload. However, for once you're correct. Hughes is doing what Hughes does best, which is politics. Hot off the web page from the FCC shows that on Friday, the FCC finally (yawn) approved using the reverse 17/24GHz DBS bands for broadcasting. Instant frequency spectrum at little price (or revenue from FCC spectrum auctions): FCC Adopts Licensing and Service Rules for the 17/24 GHz Broadcasting-Satellite Service. Sorry about the gibberish but it's so new that I can't find an intelligible press release. Notice that this is an NPR (notice of proposed rule making) and might be mutilated before being enacted.

Going foot in mouth along with this action is this little step backwards: FCC Terminates Proceeding on Receiver Interference Immunity Performance Specifications. which means that receiver quality will deteriorate to the lowest level of acceptability and that the FCC won't need to do anything about interference problems if your flashy new receiver works like crap.

Nothing on the Hughes press release site yet, but this announcement seems a bit premature: Broadband Within Reach: Hughes' New Low Price Makes Broadband Dream a Reality for Underserved Communities

There you have it. For every advance in technology and politics, the benefits go to new customers, not existing. "Effective May 7, new subscribers to HughesNet? high-speed Internet satellite service will enjoy a significant reduction in price on Hughes equipment and standard installation." Note the words "new subscribers".

I think 100:1 is permanent.

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J

John Navas hath wroth:

As I mumbled in another message, give me a specific terrestrial service provider, and I'll calculate the numbers.

Satellite does have service tiers. DirecWay and others all sell different bandwidth the FAB based service tiers. Hughesnet has several home and business tiers. See the web pages.

The DSL backhaul is most certainly shared. At some point *ALL* internet services are shared. From the point of view of the user, it doesn't matter *WHERE* the bottleneck is located. For example, Comcast/at&t has a huge amount of fiber bandwidth in the SF Bay area, but a relatively small pipe to the internet. The fiber ring could be running at a very low percentage of capacity, while the gateway to the various connection exchanges are totally constipated. To the user, it looks like oversubscription. The math is simple enough. Available bandwidth at the various connection exchanges divided by the number of Comcast/at&t customers trying to shove their traffic through those pipes.

Yep.

Quiz: What's the contention ratio (oversubscription) for a T1(DS1) within a given ILEC? Answer: 1:1 It's called committed bandwidth.

The compromise in between is usually more efficient. Adaptive polling is the way to go. Ground stations without any traffic get polled far less often than ground stations with traffic. That's also the way that ground stations are throttled (by polling them less often). There's also a hybrid which uses fixed time slots, but where the time slots are juggled depending on traffic. It's not very good and I think was invented solely to avoid a patent issue. The important thing is to reduce the amount of back and forth negotiations before sending data. Time slots do that but get into trouble when there are a huge number of ground stations. I'm not familiar with the new and improved polling protocol and therefore can't even guess how it works. Incidentally, the same polling strategy also applies to WISP systems (using WiMax and Wi-Fi) for internet access.

At this time, the FAP is not based on traffic content. The FAP does not distinguish between time criticial VoIP and non-critical file transfers. It only cares about "fair share". That may change to a QoS based FAP where one pays extra for time critical traffic.

Would it help if I posted satellite specific press releases in alt.internet.wireless? (Sorry, I just couldn't resist).

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J

On Tue, 08 May 2007 10:33:34 -0700, Jeff Liebermann wrote in :

You're misinterpreting what I wrote. My use of "tier" was in the context of pipe aggregation, which I think was pretty clear, not service levels.

Again, you're misinterpreting what I wrote. As I'm sure you know, local cable is shared, whereas local DSL isn't.

Of course. Your point?

What matters is *IF* there is a bottleneck, which is more likely with cable (due to fundamental architecture) than DSL.

Likewise for DSL to the DSLAM. Your point?

I respectfully disagree, but don't care to waste more of my life debating it -- been there, done that, long ago.

Again, you're misinterpreting what I wrote. Read what I wrote more carefully.

Whatever.

Having a bad day?

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J

On Tue, 08 May 2007 09:00:38 -0700, Jeff Liebermann wrote in :

Again, you're misinterpreting what I wrote.

Or misconstrue it entirely

I don't think so, but I'm not going to waste time debating it.

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