BTW -- the modems in the UDR56k-4 are DSP to I/Q modulation/demodulation and run on the included Linux card. The intent is to have flexibility in modems, protocols, and applications and provide an open source environment for the experimenters in the user community.
The modems, and protocol stacks, will be available on socket interfaces, so protocols and applications may run either on the radio's embedded system or via interconnection to another host.
By having on-board processing we also are looking at very low tx/rx turnaround time, well below what could be done on a USB or serial port.
One application is using the device as an 'Ethernet Bridge' within a given protocol, modem, and data rate.
Oh, and the price is a 3rd less than Bill posted :)
------------------------------ John D. Hays K7VE PO Box 1223, Edmonds, WA 98020-1223 http://k7ve.org/blog http://twitter.com/#!/john_hays http://www.facebook.com/john.d.hays
On Sat, Jun 29, 2013 at 1:33 AM, Eric Fort eric.fort@gmail.com wrote:
(Please trim inclusions from previous messages) _______________________________________________
While I can't speak for the company making the UDR56k and I have stated previously where I think it missed the mark. putting a new RF modem on an ethernet connection is a good thing. It's something kantronics should have done when the 9612 was introduced to the world. The advantage of placing it in ethernet is that one simply assigns it an address, plugs it into a (poe) hub, and it works with little to no config on the host side. many if not most who might be interested in this probably would rather not spend a huge amount of time futzing with the operating system of whatever device takes bits to or from RF. personally, I'd like to see routing functions completely divorced and separated from host services functions. if you wish to offer application layer services to amprnet then fine, put them up on a host of their own. that host should not generally also route. That just seems the be good practice. The reality is that these ethernet to RF boxen will likely intigrate into your subnet just fine and be more reliable than either serial or usb (never mind I fail to find an actual hardware serial port on ANY PC built in about the last 5 yrs....) The reality is that these don't need much in the way of computer onboard and likely never will. I don't see their intent as being something that is intended to host services and the computer needed to move bits from ethernet to 56k wireless modem should not add much cost, I'm guessing 15-20usd/unit while adding much utility.
Eric AF6EP
On Fri, Jun 28, 2013 at 11:32 PM, Michael E. Fox - N6MEF n6mef@mefox.orgwrote:
(Please trim inclusions from previous messages) _______________________________________________ I agree with you about not having the perfect locations for microwave frequencies. We have some nice sites on mountains and some not-so-nice sites with trees. So I was originally excited to read about the UDR56K.
*BUT* I, for one, am really disappointed that the UDR56K is also a linux machine. I think they screwed the pooch on that (although I understand about 300 pre-orders would disagree with me). Why do I say this? Because I already have a linux machine running JNOS (and a bunch of other stuff). I was excited about the prospect of switching our current backbone from 1200 to 56K. I was hoping to just plug it into another serial port on my existing linux machine. But it has no serial ports for my other TNCs/radios. (and adding multiple usb-serial adapters and a powered usb hub is just trouble waiting to happen). And I'm betting it doesn't have the horsepower that my existing linux system does, which runs an amprnet gateway, mail gateway, lots of iptables rules, spam and virus checking, etc., plus some automated network testing stuff. Whatever processor it does have, will be aging along the processor aging curve (speed doubles every 18 months) and to upgrade, you would throw out the radio, too - a bit of the baby and bathwater approach. In fact, forget about upgrades. If anything fails -- radio, modem, linux system memory, linux system storage -- I've got to replace the whole thing. All things fail at some point. So this just seems strange to me.
I wish they had just made the radio/modem and provided a serial port so I could connect it to whatever machine I want. I would have bought one for each of our machines, plus a spare (7). But I don't know what to do with what they built - namely a fast modem and radio hard-wired to a very limited, non-expandable linux platform. But again, I guess I'm in the minority because I understand they have about 300 pre-orders.
Oh well. Michael N6MEF