Home |
Search |
Today's Posts |
|
#1
![]() |
|||
|
|||
![]()
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 |
#2
![]() |
|||
|
|||
![]() 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 |
#3
![]() |
|||
|
|||
![]()
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 |
#4
![]() |
|||
|
|||
![]()
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 |
#5
![]() |
|||
|
|||
![]()
"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 |
#6
![]() |
|||
|
|||
![]() |
#7
![]() |
|||
|
|||
![]()
Marty Albert wrote:
I am curious as to what people attribute the (apparent) death of digital systems overall. _________________________________________________ The "new" has worn off. When a new mode or technique appears, traffic will pick up again. -- Bill, W6WRT |
Reply |
|
Thread Tools | Search this Thread |
Display Modes | |
|
|
![]() |
||||
Thread | Forum | |||
Free quick easy money Amazing !!!!!!!!!!!!! | Boatanchors | |||
Free quick easy money Amazing !!!!!!!!!!!!! | Boatanchors | |||
Free quick easy money Amazing !!!!!!!!!!!!! | Homebrew | |||
Free quick easy money Amazing !!!!!!!!!!!!! | Scanner |