Ah yes, the education of that day, based on assumptions that are still present in some form today.

Might have been a more refined age, though for today I'm pretty sure your average CS major needs to be able to quote Dante in his original language about as much as he needs an extra heavy bender prior to the big test.

The 15 million was from the OP statement of equating data to equivelent text messages.

I wasn't really addressing what the carriers charge for SMS .. they will charge what the market will bear and the market bears around $20USD per month for unlimited SMS service on a contract plan. My main point was that while SMS might be cheap to provide .. it is not entirely without cost.

The paging channel is a finite resource and ramping up the number of sms pages like the OP implied would qualify as a mass calling event like any other (new years, mothers day, natural disaster).

.. SMS messages are not like standard data .. while the payload might be 160 bytes of text, the overhead and the delivery mechanism involved is much different than your average TCP session.

Primarily because those text messages have to locate the mobile with a page on the paging channel before sending the actual text itself. Paging channel requires SS7 messages to an HLR, MSC, SMSC and some other machines that do functions other than just text.

Sending 15 million SMS to one mobile would 1. tax the MSC pretty heavily (mobile switching center) and 2. probably get the originating node blocked at the intercarrier connection point pretty quickly.

I remember an old Perkin Elmer minicomputer that was used at a laboratory testing oil samples.

The only way to get anything in or out of the thing was kermit over async serial line.

At the time I wasn't quite as UNIX headed .. I thought it very funny that the day that we installed brand new HP high volume / high capacity laser printers was the day I was asked if it had a serial interface available (why they didn't just do LPD I'll never know).

Does anyone see the irony of charging a fee to someone enrolled or trying to enroll in a program for people without money?

What are they going to do, refuse care to someone who is to obese or too poor to pay the fee.

And it got posted to the wrong thread ... /. bug anyone?

Look into a deaf/hard of hearing rate plan on one of the GSM carriers. It'll probably include a bucket of text you don't need, but it'll have data service for presumably less than a standard minutes plan. As far as the EU leg of your travels .. since your only charged for outgoing text and calls it shouldn't be too hard to get a prepaid SIM with some amount of data on it.

Though with Sprint/Virgin offering $25 a month unlimited data on a cheap android phone, it might be cheaper just to get two phones, develop on wifi when in the other country and just go with that.

Your speeds are off by about a decimal place. In mobile data terms and technical terms it breaks down like this

1G = analog / AMPS service or similiar .. 2400bp/s on a good day plus whatever hardware error correction and data compression (MNP10) -- circuit switched technology (your taking a line on the tower
2G = CDMA / GSM(CDPD) base speed data - circuit switched at 9600bp/s
2.5G = packet switched CDMA 1X / GSM GPRS or EDGE .. nominally max 144kb/s .. usually 50-70kb/s .. GSM had different EDGE profiles for higher speeds .. but the base was in this range
3G = CDMA 1XEVDO / GSM HSDPA .. 3.1mb/s on CDMA .. up to 14.4mb/s and higher on GSM (though getting a contiguous spectrum block available for the full speed is problematic when mixed with voice traffic and paging channels
3.5G = current spec WIMAX and LTE .. nominal 10mb/s down .. biggest difference is it scales to higher data rates based on number of users .. whereas say 3G CDMA might have 3.1mb/s per sector .. wimax / LTE can deliver this per user given enough spectrum
4G = most recently published goalpost .. something like 100mb/s sustained mobile and higher in fixed / limited mobility scenarios .. WIMAX2 / LTE Advanced

Well, expecting to get more output from the same input is of course illogical and impossible, but if a company puts up the planning, development and engineering resources to make it happen up front than the scalability claims in the marketing copy can be done to some extent.

But the way some (most?) deployments seem to go make it cost prohibitive to put the distributed database / distributed applications and fault tolerant components in in the first place.

1. Push everything into 5.8 range you can. Whereas 2.4 (b/g/cheap N) only has 3-4 non-contiguous channels, 5.8 (A/N) has dozens of fully non-shared channels available which should make spectrum contention less of an issue in this band.

2. depending on the geographical area required, back the power levels down using either commercial gear that allows it by default or using one of the freeware (DDWRT/Tomato) firmwares so that it doesn't exacerbate cross AP contention in B/G ranges

3. Directional antennas

4. Disable the DHCP servers in your APs and setup 2 or more subnets with their own physically separate DHCP servers.

5. If there is any AP placement flexibility, it is generally better to setup an "edges in" approach with say directional APs antenna at the perimeter and at least 4 quadrants in the central area, though if this is in the US your going to be limited to 3 non-overlapping B/G bands.

There is a diagram in the Cisco CCNA wifi study materials that has a frequency reuse map defined for maximum spectral efficiency and minimum overlap, though with only 3 mount points you won't be able to use much of that.

As far as the per user available bandwidth being small and latency going up exponentially with more users .. on paper that's true, but I find it extraordinarily unlikely that ALL users will be powering up and attempting to access all at the same time. If this were really the case than I'd say scrap the AP plan and go scounge up some 10/100 switches and go wired.

I live in Kansas with KCP&L .. my bill itemizes kw/h used multiplied by the cost per kw/h. No seperate charge based on time of day or anything else.

It might be true on the utility side where one person subsidizes another by default, but that isn't born out in the billing for residential customers. Since the value proposition of the energy storage system ITA is based on soaking up the power during off-peak rate periods and using it during peak periods .. my payback period would be much longer, which is the point I was making.

Some of these technologies are of no use to those of us that live in areas where the cost of energy is consistent all day and night and year round.

Part of that maybe the problem (no intelligence in the infrastructure). But in the meantime if I were to have solar or any other resource put up that would benefit from stored energy for later use, it'll throw the payback vs normal utility curve way off to where I'd have to live here for decades to get my money back in anything but smugness.

As far as LI battery technology, it seems that the Prius used NMhd batteries because the number of charge discharge cycles was greater, since the batteries in the story were expected to have a cycle per day, the owner would have to replace them realistically every 3-4 years.

As far as the greater energy content of LI batteries, that is a risk that is always present with batteries. As long as the controller / charger is smart and has a layer or two of fault checking, the risk of runaway thermal events is pretty low. (The problem people had with Lithium Ion AA cell batteries where they are available was when people put them into standard NiCad or NiMh chargers, which apply too much current too quickly and make them pop to start fires. Since this is an integrated system by Panasonic with no capacity to mix and match technology evident, I'd say the risks is low.)

It would be possible with standard deep cycle lead acid batteries, but than you have to have climate control for your batteries above and beyond that proposed, and than your dedicating a good chunk of floorspace to batteries (You can't stack them because of heat buildup when discharging). I know the Central Offices I've been in have had a good chunk of their floorspace dedicated to just power, and even than only for the few minutes it takes for the diesel to kick over .. and you don't want to know what happens to expensive telephone equipment when it starts getting fed progressive amounts lower than 48VDC.)

call me risk adverse .. but i was actually waiting for the final publication and n devices.

it's only recently that the n devices were cost competitive with the g devices.

now to push cisco/linksys to release an n equivelent to the wrt54gl device

While to believe the commercials from the larger players, there will never be absolutely seamless coverage across the nation because ..

1. There are places nobody lives (or it's economically unfeasible to cover)
2. Transmit powers are 1/12 of what they were in the analog era
3. They can't just throw a tower up anywhere

Back when analog bag phones were the norm, I never found anyplace without coverage .. why? Because on analog they had a nominal 3 watt transmit power on the phone, which let you have towers dozens of miles apart and still get a reliable signal. Today's mobiles operate at .25 of a watt or less, and since the 3G spec devices currently at or becoming the norm are based on CDMA technology (CDMA or WCDMA/HS?PA), the transmit power will only go down based on the load of the tower. (Under CDMA, the transmit power decreases when the load rises, lowering the noise floor and allowing more devices on the tower, with the net effect of creating islands of service if the network has hot spots and they don't plan accordingly).

As far as towers and stuff are concerned, I remember reading an article from upstate new york about a stretch of state highway that had pristine views, and a very high mortality rate in the winter because nobody had cell service up that way. The local government bodies sued and cajoled the cell carriers to build coverage, but wouldn't let them put the tall towers up to allow service in an economically feasible way. Net result, no coverage and more death, but the view was still great.