I didn't know much about wireless networking equipment but it was obvious that one could plug wireless network interface adapters into off-the-shelf PCs and so I reasoned it should be possible to build a network that way. Linux seemed like a good OS choice and so I bought some PCI IEEE802.11b NICs and rescued a couple of outdated PCs from the office junk pile.
It turned out there were some snags with this approach. First, at that time there was no way to make a Linux PC with a wireless interface card behave as an access point. Only client (station) mode and 'ad-hoc' were supported. I tried to use ad-hoc, but it transpired that it didn't really work at all (and possibly still doesn't).
The other problem was power consumption. I needed to build a relay in a location that had no utility power, which meant solar panels as the power source. Regular PCs consume way too much power to run from any reasonably sized solar panel array.
For a while I toyed with the notion of some kind of ARM-based computer with lower power dissipation, for example a PDA.
However around this time low cost and low power wireless access points appeared on the market so I decided to base my network on them.
Tuesday, October 16, 2007
Monday, October 8, 2007
Wireless Genesis
It's the spring of 2001 and I'm the proud owner of a 128Kbit ISDN Internet connection at a cost of $300/month. I learn that in the nearest town I could buy an SDSL connection for around $1/kbit, or less than half my present cost. Or double my current speed for the same price. Around this time the first IEEE802.11b is on the market and I hear from a friend that it can be used over long distances to deliver connectivity. I remember Bob Cringley was posting about how easy if was to build your own long range wireless connection.
So I began to wonder what it would take to build my own wireless network to span the 10 mile distance to town (and deal with the small matter of the medium sized mountain in the way too).
So I began to wonder what it would take to build my own wireless network to span the 10 mile distance to town (and deal with the small matter of the medium sized mountain in the way too).
You are traveling back in time...
My earliest memory of my Dad's engineering career was when he attended a conference while we were on family vacation. It must have been 1970 or thereabouts. The conference was on the new digital subscriber line technology, or ISDN.
Flash forward 30 years and we find that ISDN never really took off, but is available widely if you know the magic secret handshake that will persuade your 'phone company to admit that it is available.
In my case I learned the magic while talking to the local phone company engineering manager. He had taken pitty on me and called me in person to explain why I couldn't get T-1 service (see previous post). We chatted a bit about the equipment they used for service in our area. In passing he mentioned that the remote terminals could take any kind of line card available for the TDM bus, which included POTS, various kinds of multi-line multiplexing cards, and also ISDN. I asked if that meant ISDN service was available and he said it was.
Many weeks later, after tracking down the correct sales department at the phone company in Denver we were able to order an ISDN circuit. There then followed a period of intense confusion where it became apparent that there were exactly zero ISDN circuits deployed in our area and it would be the first time the local technical staff had put one in. The switch, it seemed, didn't have the necessary software (I'm sure it did, but probably the phone company hadn't paid for that option to be enabled). So our circuit was 'back-hauled' 125 miles from the nearest big city, Billings, where an ISDN-capable switch was available.
Eventually we had our 128Kbits ISDN Internet connection. I forget exactly the cost but the circuit was around $150/month and then the ISDN capable 'port' at UUNet was another $150/month or so.
I have repressed the memory of everything that went into buying and configuring a router that would connect to UUNet via ISDN. It would take some major hypnosis to recover that information.
I do remember that on the 128Kbits connection it only took a day to download one CD ISO image.
Flash forward 30 years and we find that ISDN never really took off, but is available widely if you know the magic secret handshake that will persuade your 'phone company to admit that it is available.
In my case I learned the magic while talking to the local phone company engineering manager. He had taken pitty on me and called me in person to explain why I couldn't get T-1 service (see previous post). We chatted a bit about the equipment they used for service in our area. In passing he mentioned that the remote terminals could take any kind of line card available for the TDM bus, which included POTS, various kinds of multi-line multiplexing cards, and also ISDN. I asked if that meant ISDN service was available and he said it was.
Many weeks later, after tracking down the correct sales department at the phone company in Denver we were able to order an ISDN circuit. There then followed a period of intense confusion where it became apparent that there were exactly zero ISDN circuits deployed in our area and it would be the first time the local technical staff had put one in. The switch, it seemed, didn't have the necessary software (I'm sure it did, but probably the phone company hadn't paid for that option to be enabled). So our circuit was 'back-hauled' 125 miles from the nearest big city, Billings, where an ISDN-capable switch was available.
Eventually we had our 128Kbits ISDN Internet connection. I forget exactly the cost but the circuit was around $150/month and then the ISDN capable 'port' at UUNet was another $150/month or so.
I have repressed the memory of everything that went into buying and configuring a router that would connect to UUNet via ISDN. It would take some major hypnosis to recover that information.
I do remember that on the 128Kbits connection it only took a day to download one CD ISO image.
What about satellite service ?
Satellite Internet service is available everywhere (unless you happen to have an immovable object blocking the high southern sky) so why didn't I have that installed ?
Well, there are a few problems with Satellite service, or at least I have a few problems with it:
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*Or schoolgirl.
Well, there are a few problems with Satellite service, or at least I have a few problems with it:
- It's a long way up to those birds. They're in geostationary orbit which any schoolboy* knows is 20-something thousand miles up. Your packets travel at the speed of light so they take 400ms to make the round trip. This latency means that some Internet applications such as interactive login, remote desktop and telephony are all but unusable.
- Upload throughput is poor. As any electronics engineer knows, it takes more power to transmit at higher bits/s. The FCC, and economics, and safety, limit the power available to transmit up to the satellite. Also the need to have clear air to transmit when there are thousands of other users sharing the same channel limits transmit duty cycle. Residential satellite connections are still today limited to around 200Kbits/s upload speed, best case.
- Speaking of best-case...the various satellite Internet providers that have come and gone over the years share one common factor : their service starts out at launch with reasonable quality of service, but degrades significantly as they sign up more and more users. This is hardly surprising since large numbers of users are sharing a common RF channel. As a user you should plan for the level of service available once your provider succeeds in signing up millions of users. If they don't succeed then you won't have service at all. If they do succeed you will have lower quality of service than you experienced initially.
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*Or schoolgirl.
The Dark Age
So it's the year 2000 and I'm living in a house where the 'phone lines give no more than 26Kbits modem service, and I'm attempting to make my living working as a remote working software engineer. The product I'm working on has a 1Gbyte build tree, makes a 50Mbyte compressed install image and often needs to be tested with hundred-megabyte databases. Things are not looking good...
For some reason the idea of renting an office in town, where at least 256Kbit DSL connections were available, didn't seem attractive. We were planning to start a family and so being around at home all day would be handy for a few years. The need to get up early in the morning to plow snow then drive on icy roads to town also didn't appeal.
I discovered that we had a six-pair phone cable at our place, and that the previous owner had three lines in use. We needed four lines already (two voice, one fax, one modem) but I wondered if it would be possible to bond two modem lines together and use a fifth phone line to double our 26Kbits speed.
These were the days when there were still real physical dial-up ISPs (today dial-up is all done by routing calls long distance to huge outsourced virtual modem banks) so I knocked on the door of the local ISP. The owner said they could provide two-line bonded service if I paid for two accounts, which I did. After the obligatory phone company screwup where they dropped all our lines instead of adding an extra one, we were upgraded to 50Kbits Internet service !
For some reason the idea of renting an office in town, where at least 256Kbit DSL connections were available, didn't seem attractive. We were planning to start a family and so being around at home all day would be handy for a few years. The need to get up early in the morning to plow snow then drive on icy roads to town also didn't appeal.
I discovered that we had a six-pair phone cable at our place, and that the previous owner had three lines in use. We needed four lines already (two voice, one fax, one modem) but I wondered if it would be possible to bond two modem lines together and use a fifth phone line to double our 26Kbits speed.
These were the days when there were still real physical dial-up ISPs (today dial-up is all done by routing calls long distance to huge outsourced virtual modem banks) so I knocked on the door of the local ISP. The owner said they could provide two-line bonded service if I paid for two accounts, which I did. After the obligatory phone company screwup where they dropped all our lines instead of adding an extra one, we were upgraded to 50Kbits Internet service !
Where's the 'Net ?
This sometimes sorry tale began in late 1999. My wife and I had decided to bail out of Silicon Valley and move to Montana. We're not exactly sure why, but the fact that we couldn't see our neighbors' houses; there were no traffic jams; and one could pop into Costco quickly to buy milk were certainly factors. In Silicon Valley nobody goes to Costco for one small item. You'd be there for an hour at least waiting in line.
House-hunting, we quickly decided that we wanted a place out of town and not on the valley floor where it's flat. That means up in the mountains where life is a little more...rugged and you have to do things for yourself. For example plow snow from the mile of road between your house and the public highway.
At that time I didn't realize that the can-do pioneer spirit would extend to building my own ISP but I did know that a) I needed an Internet connection to perform my work as a software engineer and b) that I couldn't assume that there would be any high speed internet service up in the hills. In fact back then there wasn't much in the way of DSL service in town, and no cable Internet at all.
Thinking I was so smart, I took a laptop with a modem when we went to look at houses. I'd ask the bemused Realtor if it would be ok for me to plug my laptop into the 'phone jack and then I'd see what kind of analog modem performance the lines achieved. This exercise produced mixed results. On one side of the valley modem connections could be made at 40Kbits. However on the other side it was impossible to achieve more than 26Kbits.
We decided to buy a home in the 26Kbits zone.
At this point I decided that I should call the local service providers to find out my complete set of options. In retrospect this was my big mistake.
The local phone company told me that they could provide a T-1 circuit to any point that had a phone line, no exceptions. Back then it was possible to buy 'fractional' T-1 internet service for a high but not extortionate price, so this seemed like a practical option.
The local 'CLEC' DSL company told me that they could deliver something called 'IDSL' to our location. IDSL uses legacy ISDN infrastructure to pipe 140Kbits of DSL-type service.
Both these options seemed workable, and so armed with the knowledge that we had a plan and a backup plan for Internet service, we went ahead and made an offer on our new house.
You can probably guess what happened next. The 'phone company it turned out was 100% fibbing. They actually need to perform a detailed engineering analysis on their plant in order to say if T-1 service can be delivered. Since that involves devoting the time of a smart and expensive person they don't actually do so until someone orders a circuit. It's a catch-22. You can't know if service is available without ordering service. Of course service was not available in our location because the kind of power required for HDSL repeaters (used for T-1 in the modern era) wasn't available on our local loop. Or not for the last three miles or so anyway.
The CLEC meanwhile had decided that they wouldn't make any money from IDSL and had abandoned plans to use it.
So we were now the proud owners of a wonderful home with a 26Kbit Internet connection.
House-hunting, we quickly decided that we wanted a place out of town and not on the valley floor where it's flat. That means up in the mountains where life is a little more...rugged and you have to do things for yourself. For example plow snow from the mile of road between your house and the public highway.
At that time I didn't realize that the can-do pioneer spirit would extend to building my own ISP but I did know that a) I needed an Internet connection to perform my work as a software engineer and b) that I couldn't assume that there would be any high speed internet service up in the hills. In fact back then there wasn't much in the way of DSL service in town, and no cable Internet at all.
Thinking I was so smart, I took a laptop with a modem when we went to look at houses. I'd ask the bemused Realtor if it would be ok for me to plug my laptop into the 'phone jack and then I'd see what kind of analog modem performance the lines achieved. This exercise produced mixed results. On one side of the valley modem connections could be made at 40Kbits. However on the other side it was impossible to achieve more than 26Kbits.
We decided to buy a home in the 26Kbits zone.
At this point I decided that I should call the local service providers to find out my complete set of options. In retrospect this was my big mistake.
The local phone company told me that they could provide a T-1 circuit to any point that had a phone line, no exceptions. Back then it was possible to buy 'fractional' T-1 internet service for a high but not extortionate price, so this seemed like a practical option.
The local 'CLEC' DSL company told me that they could deliver something called 'IDSL' to our location. IDSL uses legacy ISDN infrastructure to pipe 140Kbits of DSL-type service.
Both these options seemed workable, and so armed with the knowledge that we had a plan and a backup plan for Internet service, we went ahead and made an offer on our new house.
You can probably guess what happened next. The 'phone company it turned out was 100% fibbing. They actually need to perform a detailed engineering analysis on their plant in order to say if T-1 service can be delivered. Since that involves devoting the time of a smart and expensive person they don't actually do so until someone orders a circuit. It's a catch-22. You can't know if service is available without ordering service. Of course service was not available in our location because the kind of power required for HDSL repeaters (used for T-1 in the modern era) wasn't available on our local loop. Or not for the last three miles or so anyway.
The CLEC meanwhile had decided that they wouldn't make any money from IDSL and had abandoned plans to use it.
So we were now the proud owners of a wonderful home with a 26Kbit Internet connection.
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