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Amazing
I have been floating in and of this news group for about 12-15 years... Sometimes I have been an active poster and other times I am content to just lurk. What amazes me is really two things that have a very close connection (no pun intended): 1) The amount of useful and meaningful traffic in the digital modes has dropped dramatically. 2) The amount of useful and meaningful traffic on this news group has dropped dramatically. Yes, there are a few APRS nodes and some traffic there... A node simply repeating ad infinitum where it is located, what time it is, and what the temperature is at the site. Not very useful, but it is better than dead air, I suppose. While it really does not fit the definition of digital radio 100%, of much more interest are the EchoLink system and similar ideas. At least there is a combining of digital services (VoIP) and radio happening. And yes, there are a few pockets of digital services that are surviving, perhaps even thriving. But this is not the norm... Just look at the traffic in this news group or check your local BBS (if you have one) and, if you have been around for more than about 10 years or so, you will see the overall decline. I am curious as to what people attribute the (apparent) death of digital systems overall. I, of course, have my own ideas that have, by the way, not changed for more than a decade. So, what say you about the life of digital services? Take Care & 73 From The Desk Of Marty Albert KC6UFM |
Marty Albert wrote:
I am curious as to what people attribute the (apparent) death of digital systems overall. I, of course, have my own ideas that have, by the way, not changed for more than a decade. So, what say you about the life of digital services? The death of the digital modes is directly attributible to the fact that the protocol is 20 years old and has throughput equal to the speed of an old lady sitting in a motorized wheelchair trying to check-out her groceries in the express isle. TAPR had a great spread-spectrum board, but the project died a death due to a thousand cuts of various sorts. Until amateur radio gets a similar project that makes speeds 384 kbps and in a form that makes it easy for appliance operators to plug-n-play, packet is all we have. I'm surprised the ARRL hasn't sponsored a project. Kids playing with 802.11 are having far more success in building networks that amateur radio operators. |
You are correct on the speed issue... Until we can megabit+ speeds that are
easy enough for the appliance operators to use, we will likely see little growth. But as you point out, there has been little development or growth in the past 20 or so years... The interest was gone long before the "typical" ham was an appliance operator. It seems to me that, in about the same time frame, perhaps +5 years, there was a rather vocal minority that were anti-digital that drove many folks away from the modes, people who had the knowledge and skills to make high speed systems work... In about 1989 there was a local ham (now SK named Frank whose last name and call I can not remember now) who came to me with a design for a device that would plug into a 100BaseT NIC and generate low power (about 50 mW as I recall) at either 70 cm or 23 cm. He wanted my input on the protocol stack (networking is my thing). Effectively, the device simply sent and received TCP/IP over an RF Ethernet link. He had built a pair of prototypes that worked very well. He then built a simple amplifier to get the RF up to about 10 watts and it worked very well between his house and mine, about 8 miles apart, on J-Poles. We were able to get about 80 Mbps at 23 cm. He was then attacked by a few of the vocal minority fussing about their opinion that anything faster than 56 Kbps was not for "real hams" and he scraped the project rather than put up with heat from these folks. I wish that I still had the schematic for the prototype that he gave me, but over the course 15+ years and 3 cross-country moves, I have misplaced them. It would need significant updating... The prototypes were xtal controlled and did not use SS. I would think (I am a network engineer, not RF or electronics!) that the system could benefit from DDS, DSP, and SS procedures. I suspect that a team of RF, electronics, and network experts could probably reproduce the device, given the motivation and if left alone by (or were to simply ignore) the doom-sayers. And, I would wager, that the team could come up with improvements that would let get even closer to 100 Mbps, if not faster, when used on a 1000BaseT NIC. I further suspect that if such a device could be designed, built, tested, and then given to one (or more) of the several manufacturers that they would sell like hotcakes, again assuming that something could be done about the doom-sayers. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Jayson Davis" wrote in message ... Marty Albert wrote: I am curious as to what people attribute the (apparent) death of digital systems overall. I, of course, have my own ideas that have, by the way, not changed for more than a decade. So, what say you about the life of digital services? The death of the digital modes is directly attributible to the fact that the protocol is 20 years old and has throughput equal to the speed of an old lady sitting in a motorized wheelchair trying to check-out her groceries in the express isle. TAPR had a great spread-spectrum board, but the project died a death due to a thousand cuts of various sorts. Until amateur radio gets a similar project that makes speeds 384 kbps and in a form that makes it easy for appliance operators to plug-n-play, packet is all we have. I'm surprised the ARRL hasn't sponsored a project. Kids playing with 802.11 are having far more success in building networks that amateur radio operators. |
The single biggest drawback that US digital hams face is TAPR.
The second largest drawback US digital hams face is the ARRL. Between the two, they have managed to keep the US somewhere between fifteen to twenty years behind the rest of the world. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Webmaster: HamPoll.Com http://www.hampoll.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
I've been a ham for almost eleven years. The year I got started (1994)
was the same year the Web became open to commercial traffic, and I guess the decline of packet began around that time. I keep an APRS beacon on the air, and I use the local packet infrastructure. I edit my club's newsletter, and write a monthly column about digital topics. There is a small but active group of packet enthusiasts in the region that keep the nodes running, but all the same I've seen a node and a full-service BBS go dark in the last year or so. One reason for digital's decline from my point of view is a lack of interest. Obviously if the choice is reading bulletins at 1200 baud vs. DSL or even fast dialup, most folks will go with the more attractive alternative. It's too bad though that we as amateurs don't have a viable nationwide digital network. I've given the topic a lot of thought, and locally I'm trying to stir up interest in APRS since its the 'hottest' digital application we currently have that is available to most hams cheaply. From an emergency communications perspective, we could potentially make a better case for our existence if we had a national network that was 100% independent of the wired public infrastrucure (including the Internet). Now, the ARRL is pushing Winlink 2000. I sat through a forum on the topic two or three years ago at the Timonium, MD hamfest. I know about the controversy surrounding it, but at least it provides a way to pass email traffic via the client programs that people are accustomed to using. Besides lack of interest, there is always the cost factor. I don't know what it costs to operate a typical node, but for a hobby it must be expensive. Its obviously a labor of love for the sysops out there, given the small amount of traffic and small number of users. A local node/BBS seems to have gone out of service. It was a TCP/IP and AX.25 board, as well as an Internet gateway node. Maybe the connectivity costs got to be too much, I don't know. Without users, even the most dedicated packet sysop must eventually question the reason for maintaining his or her system. I also understand that tower space is getting more difficult to obtain and hold onto. I think establishing high-speed backbones on a regional basis, using 802.11 technology under Part 97 rules, or maybe the Icom D-Star system, would be useful. The problem there is cost and the tremendous effort that would be involved. In theory, a group of clubs with repeaters that have line-of-sight could get together and build a backbone linking those repeater sites. Now I'm talking TCP/IP, so there is another problem. I'm interested in doing amateur TCP/IP, but when I emailed my regional Amprnet coordinator for an IP address, I received zero response. Imagine the value the ham community could offer if we had networks ringing the major cities. I don't believe we need to recreate the Internet or try to compete with anything that exists currently. But to support emergency services effectively with a robust network would really go a long way to justifying our continued existence. Matt, N3SOZ Marty Albert wrote: I have been floating in and of this news group for about 12-15 years... Sometimes I have been an active poster and other times I am content to just lurk. What amazes me is really two things that have a very close connection (no pun intended): 1) The amount of useful and meaningful traffic in the digital modes has dropped dramatically. 2) The amount of useful and meaningful traffic on this news group has dropped dramatically. Yes, there are a few APRS nodes and some traffic there... A node simply repeating ad infinitum where it is located, what time it is, and what the temperature is at the site. Not very useful, but it is better than dead air, I suppose. While it really does not fit the definition of digital radio 100%, of much more interest are the EchoLink system and similar ideas. At least there is a combining of digital services (VoIP) and radio happening. And yes, there are a few pockets of digital services that are surviving, perhaps even thriving. But this is not the norm... Just look at the traffic in this news group or check your local BBS (if you have one) and, if you have been around for more than about 10 years or so, you will see the overall decline. I am curious as to what people attribute the (apparent) death of digital systems overall. I, of course, have my own ideas that have, by the way, not changed for more than a decade. So, what say you about the life of digital services? Take Care & 73 From The Desk Of Marty Albert KC6UFM |
"n3soz" wrote in message
oups.com... Imagine the value the ham community could offer if we had networks ringing the major cities. I don't believe we need to recreate the Internet or try to compete with anything that exists currently. But to support emergency services effectively with a robust network would really go a long way to justifying our continued existence. Matt, N3SOZ Exactly what we are doing here in Portland, OR. Lots of fun. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Charles Brabham" wrote in message . .. The single biggest drawback that US digital hams face is TAPR. The second largest drawback US digital hams face is the ARRL. Between the two, they have managed to keep the US somewhere between fifteen to twenty years behind the rest of the world. Charles Brabham, N5PVL There is nothing stopping the hams from changing it except for lack of money. Too many people come up with these grandiose ideas and expect somebody to fund it. Well it isn't going to happen. Many clubs are struggling just to keep their repeaters funded and maintained. Individuals face dilemmas of their own on how to allocate their financial priorities. Dee D. Flint, N8UZE |
Up to a point, I think that you are correct, but there far more dynamic
forces acting on this than just the ARRL and TAPR. (a side note: I gave up membership in both about 1991) Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Charles Brabham" wrote in message . .. The single biggest drawback that US digital hams face is TAPR. The second largest drawback US digital hams face is the ARRL. Between the two, they have managed to keep the US somewhere between fifteen to twenty years behind the rest of the world. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Webmaster: HamPoll.Com http://www.hampoll.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
You are 100% correct... Lack of interest is, in my opinion, the largest
single factor. The speed is also a big deal, as you say... 1200 bps vs. a 2-4 Mbps cable connection seems to be a slam dunk. But, keep in mind that we are talking about is an easy to build and use device that, with a 15+ year old design, was known to 80 Mbps over a fairly short path. That sort of makes mucking about with 802.11 junk sort of a wasted effort. The mistake was made about 15 years ago when the drive was to effectively duplicate the Internet on the ham bands. Simply put, there are not, never have been, and likely never will be enough hams in the world to do that. Besides, why try to duplicate a defective system? For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed by an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the city. A series of 1 Gbps nodes come off of the spokes to feed into the neighborhood. In the neighborhoods, picture a bridge node that users can connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being connected to other city wheels at 10 Gbps. Are you drooling yet? :) Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "n3soz" wrote in message oups.com... I've been a ham for almost eleven years. The year I got started (1994) was the same year the Web became open to commercial traffic, and I guess the decline of packet began around that time. I keep an APRS snipped for space's sake |
Yep... Who will pay for it?
The gizmo that Frank designed (16+ years ago) could be built for about $25.00 (USD) buying the parts retail. I would suspect that, at that time, a manufacturer going all out in building and selling these things could have got all the parts for around $4.00 or so. With a redesign to take advantage of today's DDS, DSP, SS, uControllers, etc., I would suspect that manufacturer, buying in lots to build 5000 units, would probably pay about $6.00 for the parts and perhaps another $8.00 in labor. That would put their wholesale price to dealers at about $40.00 and retail price at about $80-$100. You'll pay that for a 1200 bps TNC! But, actual prices aside, we hams need to start doing some innovative and interesting things that private industry can pick up on and make a few dollars. Want to get really bad news? Go to the FCC site and take a look at what bands the size of, for example, our 70 cm band are selling for at auction. Hams in the US are probably sitting on a couple of billion dollars worth of bandwidth. How long do you think it will be before some congress critter notices that hams, (A) Ham a lot of valuable bandwidth, (B) Have not contributed very much to the electronics or radio industries since the early 1950's, (C) Are shrinking in numbers and spend most of their time acting just like CBer's, and (D) Are basically a moot point when it comes to emergency communications. In other words, the people that really like ham radio will come up with the money because it matters to them if it goes away. And, BTW, there were the same arguments about money when we had a lot of privately owned BBSs for computer users to call into. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Dee Flint" wrote in message ... There is nothing stopping the hams from changing it except for lack of money. Too many people come up with these grandiose ideas and expect somebody to fund it. Well it isn't going to happen. Many clubs are struggling just to keep their repeaters funded and maintained. Individuals face dilemmas of their own on how to allocate their financial priorities. Dee D. Flint, N8UZE |
Marty Albert wrote:
For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... What was the on-the-air bandwidth of Frank's 80Mbps signal? Dana K6JQ |
Marty,
Yes I am drooling over the possibility. Like you I can imagine these fantastic star networks ringing the big metro areas. I think though that to be feasible the community needs to look at whats available off-the-shelf. Obviously if someone technically brilliant can take Frank's idea and build something that can be cheaply manufactured, that would be ideal. But Icom's D-Star system is available, and hams are using 802.11 access points with amplifiers and directional antennas (www.arrl.org/hsmm/). Maybe a club somewhere has a network like this already running. It would take a dedicated group of hams with some fairly serious resources (capital, access to good sites, know-how) to pull something like this off. In my area a small group of ATV guys have put up a repeater, and have established several sites at EOC's, with the goal of providing ATV "on-demand" to emergency officials. A network project could piggyback on something like that. Matt, N3SOZ Marty Albert wrote: For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed by an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the city. A series of 1 Gbps nodes come off of the spokes to feed into the neighborhood. In the neighborhoods, picture a bridge node that users can connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being connected to other city wheels at 10 Gbps. Are you drooling yet? :) Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "n3soz" wrote in message oups.com... I've been a ham for almost eleven years. The year I got started (1994) was the same year the Web became open to commercial traffic, and I guess the decline of packet began around that time. I keep an APRS snipped for space's sake |
As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around 100 KHz on the "final" design... That design incorporated TDM, limited SS, and WDM of the signals. Obviously, with multiple forms of simultaneous multiplexing, the bandwidth would through the roof, most likely to around 100-150 MHz. Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks and, assuming a target data-rate of 100 Mbps, get the on air bandwidth down to around 50-75 KHz, maybe even a little less. With a similar set up except for a target data-rate of 10 Gbps, my back-of-the-envelope calculations are coming up with an on air bandwidth on the order of 30-50 MHz. There may be as much as a 10-15% decrease in bandwidth by using a well designed DSP. Essentially we would need to look carefully at the Ethernet 10+ Gbps over copper and copy those concepts... I have my upper division and grad students looking at ways to do just that.I am hoping in the next month or so, I can reach an agreement with EE department and the RF engineering department to bring in some of their students to help out with those aspects... My students have already found one thing... BASIC Stamps and PIC processors will only work up to about 115 Mbps. Beyond that, they are just too slow. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Dana H. Myers" wrote in message ... What was the on-the-air bandwidth of Frank's 80Mbps signal? Dana K6JQ |
Marty Albert wrote:
As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around 100 KHz on the "final" design... That design incorporated TDM, limited SS, and WDM of the signals. What exactly does this all mean? Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds pretty fantastic - to the extent that makes me question the validity of the measurements. Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks and, assuming a target data-rate of 100 Mbps, get the on air bandwidth down to around 50-75 KHz, maybe even a little less. Whoa. Hold on. Help me understand what units and methods of measurement you're using. Right now, you're off by several decimal places in even the most generous way. Dana K6JQ |
"Dana H. Myers" wrote in message
... Marty Albert wrote: As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around 100 KHz on the "final" design... That design incorporated TDM, limited SS, and WDM of the signals. What exactly does this all mean? Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds pretty fantastic - to the extent that makes me question the validity of the measurements. This in 100 Hz of bandwidth we can obtain 80 Kbps. Shannon twirling in his grave. Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks and, assuming a target data-rate of 100 Mbps, get the on air bandwidth down to around 50-75 KHz, maybe even a little less. Whoa. Hold on. Help me understand what units and methods of measurement you're using. Right now, you're off by several decimal places in even the most generous way. Lost a decimal point for sure. BTW ... why does everyone always mention 1200 baud? Doesn't everyone use at least 9600 for local links, and PACTOR II / III on HF? Think I have a 1200 baud TNC around here ... yeah there it is over in that cabinet. Big black box, says TAPR TNC-1 on it. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"n3soz" wrote in message
oups.com... Marty, Yes I am drooling over the possibility. Like you I can imagine these fantastic star networks ringing the big metro areas. I think though So do it! WiFi gear getting cheap, run it within the ham band. Works fine. that to be feasible the community needs to look at whats available off-the-shelf. Obviously if someone technically brilliant can take Frank's idea and build something that can be cheaply manufactured, that would be ideal. But Icom's D-Star system is available, and hams are using 802.11 access points with amplifiers and directional antennas (www.arrl.org/hsmm/). Maybe a club somewhere has a network like this already running. It would take a dedicated group of hams with some fairly serious resources (capital, access to good sites, know-how) to pull something like this off. In my area a small group of ATV guys have put up a repeater, and have established several sites at EOC's, with the goal of providing ATV "on-demand" to emergency officials. A network project could piggyback on something like that. Matt, N3SOZ Marty Albert wrote: For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed by an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the city. A series of 1 Gbps nodes come off of the spokes to feed into the neighborhood. In the neighborhoods, picture a bridge node that users can connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being connected to other city wheels at 10 Gbps. Are you drooling yet? :) -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
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"news" wrote in message
... In message et, Hank Oredson writes So do it! WiFi gear getting cheap, run it within the ham band. Works fine. Hank (or anyone else), Can you point me to reflectors/forums for WiFi ham band networks? I would like to catch up with what people are doing in this area. You just hook it up ... totally simple. Might want an amplifier and good antenna. Took me about 3 minutes to get a WiFi link running here. It was between two packet BBS nodes (running SNOS) and two Windows machines. "It just works." -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"news" wrote in message ... Can you point me to reflectors/forums for WiFi ham band networks? I would like to catch up with what people are doing in this area. I can give an overview of what's being accomplished in this area... Summary: Lots of hot air, accompanied by little or no action. As far as I can tell, nobody has utilized the WIFI/SHF stuff in a substantial way. There are lots of "mini-networks" here and there, but I have yet to hear about anything of an established, permanent nature that "rings a metroplolis" or even a small town. Another common networking task that has gone unreported is linking packet nets in two cities via WIFI/SHF links. Nobody has stepped forward to even claim to have accomplished that basic task. The ARRL HSMM group has been around for years and years now - but there is no substantial WIFI/SHF amateur radio network - anywhere - to show for it. The same applies to the dozens of WIFI/SHF reflectors and forums that have popped up over the last decade. Lots of speculation and nit-picking technical arguement - but no usable network. ( On any substantial scale. ) There is really no particular reason why these things could not be done. It is all well within the realm of possibility, but for some reason there has been no particular effort to utilize WIFI/SHF equipment for these basic networking applications, except on a small, local scale. I've noted that even the small LANs that pop up from time to time utilizing WIFI/SHF gear seldom stay in operation for very long. Why? - My explanation for this is that the same amateurs who tend to be interested in WIFI also tend to disparage the idea of established amateur radio digital networking. - They all appear to believe that we would be a lot better off to just use the Internet instead of building independent amateur radio infrastructure. - So they don't do it. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Webmaster: HamPoll.Com http://www.hampoll.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
"Charles Brabham" writes:
Why? - My explanation for this is that the same amateurs who tend to be interested in WIFI also tend to disparage the idea of established amateur radio digital networking. - They all appear to believe that we would be a lot better off to just use the Internet instead of building independent amateur radio infrastructure. - So they don't do it. It could also be that they're more interested in low-speed DX networks than local wifi-like networks. Wifi works perfectly well on part 15 with no licenses needed. Why bother with a licensed version of the same thing? And how do you re-tune the wifi cards to ham bands anyway? |
"news" wrote in message
... In message . net, Hank Oredson writes You just hook it up ... totally simple. Might want an amplifier and good antenna. Took me about 3 minutes to get a WiFi link running here. It was between two packet BBS nodes (running SNOS) and two Windows machines. "It just works." Yup, I can see that, but it's the "amplifier and good antenna" bit that I'm particularly interested in. What do people use? URLs? It's a long topic. There are many many options. Use Google. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Charles Brabham" wrote in message
m... "news" wrote in message ... Can you point me to reflectors/forums for WiFi ham band networks? I would like to catch up with what people are doing in this area. I can give an overview of what's being accomplished in this area... Summary: Lots of hot air, accompanied by little or no action. We have done some test links, to verify path issues. Then we did the cost analysis. About $2k per endpoint for the paths we need to cover. So we have some short links, but any interesting links require investment from a group of hams instead of a single ham. That has not happened. As far as I can tell, nobody has utilized the WIFI/SHF stuff in a substantial way. There are lots of "mini-networks" here and there, but I have yet to hear about anything of an established, permanent nature that "rings a metroplolis" or even a small town. Another common networking task that has gone unreported is linking packet nets in two cities via WIFI/SHF links. Nobody has stepped forward to even claim to have accomplished that basic task. The problem is cost. The ARRL HSMM group has been around for years and years now - but there is no substantial WIFI/SHF amateur radio network - anywhere - to show for it. The same applies to the dozens of WIFI/SHF reflectors and forums that have popped up over the last decade. Lots of speculation and nit-picking technical arguement - but no usable network. ( On any substantial scale. ) The technical issues are simple to solve, they just involve money to buy amplifiers, coax, antennas. The money issue cannot be solved. There is really no particular reason why these things could not be done. It is all well within the realm of possibility, but for some reason there has been no particular effort to utilize WIFI/SHF equipment for these basic networking applications, except on a small, local scale. I've noted that even the small LANs that pop up from time to time utilizing WIFI/SHF gear seldom stay in operation for very long. It's money. Why? - My explanation for this is that the same amateurs who tend to be interested in WIFI also tend to disparage the idea of established amateur radio digital networking. - They all appear to believe that we would be a lot better off to just use the Internet instead of building independent amateur radio infrastructure. - So they don't do it. That has not happened here. We just don't have the money to do it. Note that the Portland Metro area is broken up by many large and small hills. We need at least two dozen sites to cover the whole area. At a few $k per site we are talking total investment greater than $50,000. We have had 9600 in place for years, but those sites will mostly not work for WiFi. Think "wet trees". -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Paul Rubin" wrote in message
... "Charles Brabham" writes: Why? - My explanation for this is that the same amateurs who tend to be interested in WIFI also tend to disparage the idea of established amateur radio digital networking. - They all appear to believe that we would be a lot better off to just use the Internet instead of building independent amateur radio infrastructure. - So they don't do it. It could also be that they're more interested in low-speed DX networks than local wifi-like networks. Wifi works perfectly well on part 15 with no licenses needed. Why bother with a licensed version of the same thing? And how do you re-tune the wifi cards to ham bands anyway? Hams can run more power, use larger antennas, and cover reasonable distances. But you knew that, right? -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Radio Active" wrote in message
... On Wed, 18 May 2005 03:45:42 GMT, "Marty Albert" was heard mumbling in the corner: You are 100% correct... Lack of interest is, in my opinion, the largest single factor. The speed is also a big deal, as you say... 1200 bps vs. a 2-4 Mbps cable connection seems to be a slam dunk. The higher the speed the more the bandwidth needed to support it. We don't have the bandwidth in any of the spectrum we have to support 2-4 Mbps. What ??? You are joking, right? But, keep in mind that we are talking about is an easy to build and use device that, with a 15+ year old design, was known to 80 Mbps over a fairly short path. How much bandwidth did it use? That sort of makes mucking about with 802.11 junk sort of a wasted effort. ROFLOL! The mistake was made about 15 years ago when the drive was to effectively duplicate the Internet on the ham bands. Simply put, there are not, never have been, and likely never will be enough hams in the world to do that. Besides, why try to duplicate a defective system? The internet is defective? Interesting. So, your idea of what amateur radio should be is a national digital communications network? You have no room for other modes of communications? No SSB? No CW? For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... Look at the bandwidth 1200 bps or 9600 bps uses and then figure out what 512 Mbps would take up. Then read Part 97. What's the problem? Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed by an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the city. A series of 1 Gbps nodes come off of the spokes to feed into the neighborhood. In the neighborhoods, picture a bridge node that users can connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being connected to other city wheels at 10 Gbps. And just where are you going to get that much radio spectrum to do that? SHF. We already have the spectrum. Are you drooling yet? :) No, I'm laughing. Clueless but happy. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
I agree that this is vital to any large-scale regional network - don't
shut out the current packet infrastructure. I know there are TCP/IP nodes that also support AX.25 connections so this should be possible. As to why this hasn't been done on a large scale - it would require quite a bit of cooperation. A star topology would require several sites with line-of-sight. Imagine a situation where four ham clubs happen to have repeater sites that had line-of-sight, and your task was to "sell" the backbone network concept to every club, and arrange the logisitics of getting it all built. Besides raising funds there would be issues of ownership and administration. quote: Another common networking task that has gone unreported is linking packet nets in two cities via WIFI/SHF links. Nobody has stepped forward to even claim to have accomplished that basic task. Why? - My explanation for this is that the same amateurs who tend to be interested in WIFI also tend to disparage the idea of established amateur radio digital networking |
TDM = Time Domain Multiplexing
WDM = Wide Dimensional Multiplexing SDM = Statistical Domain Multiplexing. TDM and, to a limited degree, WDM have been around and used for several decades in high performance networking. SDM is relatively new, about 5 years. There are far more ways to multiplex intelligence on a medium than PSK and FSK, although both are used in high performance systems. You are 100% correct... I may very well a few decimal places off... The mathematical models show that 100 Mbps should be possible in as little as 10 KHz. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Dana H. Myers" wrote in message ... Marty Albert wrote: As I recall, at 23 cm and 80 Mbps we had an effective bandwidth of around 100 KHz on the "final" design... That design incorporated TDM, limited SS, and WDM of the signals. What exactly does this all mean? Passing 80,000,000 bits/sec in 100,000Hz of bandwidth sounds pretty fantastic - to the extent that makes me question the validity of the measurements. Today, we could use TDM, WDM, SDM, high-end SS, and a few other tricks and, assuming a target data-rate of 100 Mbps, get the on air bandwidth down to around 50-75 KHz, maybe even a little less. Whoa. Hold on. Help me understand what units and methods of measurement you're using. Right now, you're off by several decimal places in even the most generous way. Dana K6JQ |
"Marty Albert" writes:
You are 100% correct... I may very well a few decimal places off... The mathematical models show that 100 Mbps should be possible in as little as 10 KHz. Yes, you are a few decimal places off, but in the wrong direction ;-). |
Amen to that, Hank...
-- From The Desk Of Marty Albert, KC6UFM "Hank Oredson" wrote in message . net... "Radio Active" wrote in message ... On Wed, 18 May 2005 03:45:42 GMT, "Marty Albert" was heard mumbling in the corner: You are 100% correct... Lack of interest is, in my opinion, the largest single factor. The speed is also a big deal, as you say... 1200 bps vs. a 2-4 Mbps cable connection seems to be a slam dunk. The higher the speed the more the bandwidth needed to support it. We don't have the bandwidth in any of the spectrum we have to support 2-4 Mbps. What ??? You are joking, right? But, keep in mind that we are talking about is an easy to build and use device that, with a 15+ year old design, was known to 80 Mbps over a fairly short path. How much bandwidth did it use? That sort of makes mucking about with 802.11 junk sort of a wasted effort. ROFLOL! The mistake was made about 15 years ago when the drive was to effectively duplicate the Internet on the ham bands. Simply put, there are not, never have been, and likely never will be enough hams in the world to do that. Besides, why try to duplicate a defective system? The internet is defective? Interesting. So, your idea of what amateur radio should be is a national digital communications network? You have no room for other modes of communications? No SSB? No CW? For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... Look at the bandwidth 1200 bps or 9600 bps uses and then figure out what 512 Mbps would take up. Then read Part 97. What's the problem? Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed by an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the city. A series of 1 Gbps nodes come off of the spokes to feed into the neighborhood. In the neighborhoods, picture a bridge node that users can connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being connected to other city wheels at 10 Gbps. And just where are you going to get that much radio spectrum to do that? SHF. We already have the spectrum. Are you drooling yet? :) No, I'm laughing. Clueless but happy. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"n3soz" wrote in message ups.com... I agree that this is vital to any large-scale regional network - don't shut out the current packet infrastructure. I know there are TCP/IP nodes that also support AX.25 connections so this should be possible. As to why this hasn't been done on a large scale - it would require quite a bit of cooperation. A star topology would require several sites with line-of-sight. Imagine a situation where four ham clubs happen to have repeater sites that had line-of-sight, and your task was to "sell" the backbone network concept to every club, and arrange the logisitics of getting it all built. Besides raising funds there would be issues of ownership and administration. The Star network topology has been tried with Packet. It was called TexNet. The TexNet network did something that no other large-scale ax25 packet network ever did - It disappeared completely, leaving hardly any trace behind to show that it once existed.. From 100+ linked nodes to none in just a few years. I suppose that would qualify TexNet as the worst disaster in the history of digital amateur radio. It's untimely demise was directly related to the use of the obsolete Star network topology. All the other large-scale packet networks used the same Partially-Meshed network topology that the Internet utilizes, and I notice that all of those are still around to this day. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Webmaster: HamPoll.Com http://www.hampoll.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
"Hank Oredson" wrote in message k.net... We have done some test links, to verify path issues. Then we did the cost analysis. About $2k per endpoint for the paths we need to cover. So we have some short links, but any interesting links require investment from a group of hams instead of a single ham. That has not happened. The problem is cost. By interesting, I assume you are talking about links that can be located a reasonable distance apart. I've been curious about this for quite a while. I use ethernet cable at home so I have no experience with WIFI equipment. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Webmaster: HamPoll.Com http://www.hampoll.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
Charles,
Did some background reading, guess I've used the wrong terminology. I've had a few networking classes but I'm no expert. The partially meshed topology is definitely the way to go. But the issues of selling the concept and handling funding and logistics that I mentioned are still a factor in any large-scale network implementation. As other posters have mentioned, we have the bandwidth available to get this done but money is the major obstacle. I'm just glad this conversation is happening here. The original poster hit a nerve and clearly there is interest in moving digital amateur radio networking forward. I'm going to look at what I can do within my club, using our facilities - some kind of happy medium between setting up a network in my house and covering 500 square miles. Gotta walk before you can run. Matt, N3SOZ Charles Brabham wrote: The Star network topology has been tried with Packet. It was called TexNet. The TexNet network did something that no other large-scale ax25 packet network ever did - It disappeared completely, leaving hardly any trace behind to show that it once existed.. From 100+ linked nodes to none in just a few years. I suppose that would qualify TexNet as the worst disaster in the history of digital amateur radio. It's untimely demise was directly related to the use of the obsolete Star network topology. All the other large-scale packet networks used the same Partially-Meshed network topology that the Internet utilizes, and I notice that all of those are still around to this day. Charles Brabham, N5PVL Director: USPacket http://www.uspacket.org Admin: HamBlog.Com http://www.hamblog.com Webmaster: HamPoll.Com http://www.hampoll.com Weblog: http://www.hamblog.com/blog_n5pvl.php |
"Marty Albert" wrote in message
... TDM = Time Domain Multiplexing WDM = Wide Dimensional Multiplexing SDM = Statistical Domain Multiplexing. TDM and, to a limited degree, WDM have been around and used for several decades in high performance networking. SDM is relatively new, about 5 years. There are far more ways to multiplex intelligence on a medium than PSK and FSK, although both are used in high performance systems. You are 100% correct... I may very well a few decimal places off... The mathematical models show that 100 Mbps should be possible in as little as 10 KHz. The model is wrong. Post it and I'll be glad to explain why. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Charles Brabham" wrote in message
... "Hank Oredson" wrote in message k.net... We have done some test links, to verify path issues. Then we did the cost analysis. About $2k per endpoint for the paths we need to cover. So we have some short links, but any interesting links require investment from a group of hams instead of a single ham. That has not happened. The problem is cost. By interesting, I assume you are talking about links that can be located a reasonable distance apart. Five to fifty miles. All costs included, things like towers, etc. as well as the dishes and amplifiers. I've been curious about this for quite a while. I use ethernet cable at home so I have no experience with WIFI equipment. It can be very easy to set up, played with it here, but ordinary WiFi won't even get from one end my house to the other. So there are a few hundred feet of CAT5 instead :-) -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Hank Oredson" writes:
Five to fifty miles. All costs included, things like towers, etc. as well as the dishes and amplifiers. What are you using for the underlying RF? Ordinary wifi cards? How did you get them to operate outside the part 15 band? |
"Paul Rubin" wrote in message
... "Hank Oredson" writes: Five to fifty miles. All costs included, things like towers, etc. as well as the dishes and amplifiers. What are you using for the underlying RF? Ordinary wifi cards? Ordinary WiFi cards. How did you get them to operate outside the part 15 band? Look at your favorite frequency allocation chart. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
"Radio Active" wrote in message
... On Fri, 20 May 2005 14:33:20 GMT, "Hank Oredson" was heard mumbling in the corner: "Radio Active" wrote in message . .. On Wed, 18 May 2005 03:45:42 GMT, "Marty Albert" was heard mumbling in the corner: You are 100% correct... Lack of interest is, in my opinion, the largest single factor. The speed is also a big deal, as you say... 1200 bps vs. a 2-4 Mbps cable connection seems to be a slam dunk. The higher the speed the more the bandwidth needed to support it. We don't have the bandwidth in any of the spectrum we have to support 2-4 Mbps. What ??? You are joking, right? Not in the least. We don't have MHz of bandwidth to give up for something that only a few would use. Of the 700,000 US hams, how many do you think would be interested in such a thing? Ah, never mind, a really ignorant troll. But, keep in mind that we are talking about is an easy to build and use device that, with a 15+ year old design, was known to 80 Mbps over a fairly short path. How much bandwidth did it use? That sort of makes mucking about with 802.11 junk sort of a wasted effort. ROFLOL! The mistake was made about 15 years ago when the drive was to effectively duplicate the Internet on the ham bands. Simply put, there are not, never have been, and likely never will be enough hams in the world to do that. Besides, why try to duplicate a defective system? The internet is defective? Interesting. So, your idea of what amateur radio should be is a national digital communications network? You have no room for other modes of communications? No SSB? No CW? For the life of me, I can see no reason why Frank's device could not be re-designed today to well over 512 Mbps, perhaps very close to gigabit speeds. If you make the jump to the new copper solutions for 10 Gbps, we may even be able to get close to that... Look at the bandwidth 1200 bps or 9600 bps uses and then figure out what 512 Mbps would take up. Then read Part 97. What's the problem? If you can figure it out, I doubt anyone would be able to explain it to you. See above comment. Imagine a large metropolitan area, like maybe Dallas/Fort Worth, ringed by an 8 Gbps nodes with spokes at 8 Gbps "dropping" into and through the city. A series of 1 Gbps nodes come off of the spokes to feed into the neighborhood. In the neighborhoods, picture a bridge node that users can connect to at, say, 100 Mbps. Lastly, picture these "City Wheels" being connected to other city wheels at 10 Gbps. And just where are you going to get that much radio spectrum to do that? SHF. We already have the spectrum. Oh? We do? Yes. Are you drooling yet? :) No, I'm laughing. Clueless but happy. Ah, here we go with the insults. Plonk! Ah yes, place hands firmly over ears. Imagine how much we will miss you. Next time post using your callsign in your sig. -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli |
I will see if the University that I am using to develop the model will allow
that at this point... It is actually their intellectual property. I doubt, however that you will find any major errors in the algorithms.... There have been many professors, PhDs, and grad students looking at it to find those errors as well as engineers from Motorola, Maxim, and TI. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Hank Oredson" wrote in message ink.net... The model is wrong. Post it and I'll be glad to explain why. |
"The mathematical models show that 100 Mbps
should be possible in as little as 10 KHz." If that is what it shows, there is an error. The error is either with the model itself, or with the assumptions fed into the model. Basic Thermo 101 ... Shannon ... etc. However, if you can get me 100 Mbps in 10 KHz, I'll be glad to buy a whole bunch of 'em :-) -- ... Hank http://home.earthlink.net/~horedson http://home.earthlink.net/~w0rli "Marty Albert" wrote in message om... I will see if the University that I am using to develop the model will allow that at this point... It is actually their intellectual property. I doubt, however that you will find any major errors in the algorithms.... There have been many professors, PhDs, and grad students looking at it to find those errors as well as engineers from Motorola, Maxim, and TI. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Hank Oredson" wrote in message ink.net... The model is wrong. Post it and I'll be glad to explain why. |
In article "Marty Albert" writes:
I will see if the University that I am using to develop the model will allow that at this point... It is actually their intellectual property. I doubt, however that you will find any major errors in the algorithms.... There have been many professors, PhDs, and grad students looking at it to find those errors as well as engineers from Motorola, Maxim, and TI. Take Care & 73 -- From The Desk Of Marty Albert, KC6UFM "Hank Oredson" wrote in message link.net... The model is wrong. Post it and I'll be glad to explain why. A few things come to mind: 1) Multiplexing does not increase the bandwidth capability of a channel. You mention various forms of multiplexing, but these will not increase the channel capacity. They are just different ways of utilizing what is available. 2) The Hartley-Shannon Law gives the maximum bandwidth of a channel as C = B log2(1+(s/n)) bits/second; where B is bandwidth (Hz) and s/n is expressed as a value, not in dB. Given this, to get 80 megabits of signal in a 100 kilobit channel, you will need a signal/noise ratio of about 2408 dB. Since you were only starting with a 10 watt signal, with about 100 dB path loss (after including the two j-poles), and a terrrestrial noise floor of about -124 dBm for the 100 kHz wide channel, you get only about 60 - 64 dB s/n in your receiver (assuming things like lossless coax, etc.). Thus you are about 2340 dB short on signal to accomplish the task as described. See http://encyclopedia.laborlawtalk.com/Shannon_limit for more discussion of this. Your numbers are a bit too far from what can reasonably be believed. Alan wa6azp |
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