Topics

[44net] hardware vs. software

K7VE - John <john@...>
 

MIchael,

I don't have time right now to test, but JNOS2 compiles from source on the UDR56k-4 as does jnosinstaller.  The installer configures the program just fine.

Barring any unforeseen issues, you should be able to run JNOS directly on the radio.  If you have TNCs servicing local LANs (e.g. 2 meters, 220, ...), you can put USB-to-Serial interfaces on the UDR56k-4 and attach the TNCs with their current radios. No other computer would be required.  We have tested TNCs attached in this manner on other applications for over a year (daily).  The four UDR56k-4s would form your backbone radios.  AX.25 drivers are already in place to drive the UDR56k-4 at any supported speed including 9600-baud to over 56k baud (with some steps in between).  You would use a CIDR of /29 if these were the only radios on your backbone LAN.

This is an open architure/system so bring your favorite applications (Linux source or Linux ARMEL binaries) to the radio.  If your application is more appropriate to run on another computer, use the UDR56k-4 as a relay device, using an IP interface (wired or wireless).

Further discussion on the UniversalDigitalRadio forum on Yahoo! Groups.



John D. Hays
K7VE
PO Box 1223, Edmonds, WA 98020-1223 
  


On Sat, Jul 6, 2013 at 9:15 AM, Michael E. Fox - N6MEF <n6mef@...> wrote:
(Please trim inclusions from previous messages)
_______________________________________________
John,

I'm glad you're on this list.  Didn't realize that.

I've look and found no "solution" oriented documentation -- i.e. how can I
use the device?  All of the information about the internals, like "socket
interfaces" may have meaning for some.  But, since I don't write protocol
internals, it doesn't help me understand the deployment scenarios.

For example, assume I have four JNOS systems that are currently connected to
each other on a single subnet using a single 440 frequency.  They talk to
each other using IP over AX.25.  I would definitely like to increase the
speed.  But it's not clear to me how I would deploy the UDR56K-4 to replace
the existing 440 radios/TNCs.  What protocol would it run, at what speed?
What would the IP network diagram look like?

If this question is not appropriate for the 44-list, we can move it to your
yahoo group.

Thanks much,
Michael
N6MEF

-----Original Message-----
From: 44net-bounces+n6mef=mefox.org@...
[mailto:44net-bounces+n6mef=mefox.org@...] On Behalf Of K7VE -
John
Sent: Friday, July 05, 2013 11:02 PM
To: AMPRNet working group
Subject: Re: [44net] hardware vs. software

(Please trim inclusions from previous messages)
_______________________________________________
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 :)


_________________________________________
44Net mailing list
44Net@....edu
http://hamradio.ucsd.edu/mailman/listinfo/44net
http://www.ampr.org/donate.html

"John D. Hays" <john@...>
 

MIchael,

I don't have time right now to test, but JNOS2 compiles from source on the UDR56k-4 as does jnosinstaller.  The installer configures the program just fine.

Barring any unforeseen issues, you should be able to run JNOS directly on the radio.  If you have TNCs servicing local LANs (e.g. 2 meters, 220, ...), you can put USB-to-Serial interfaces on the UDR56k-4 and attach the TNCs with their current radios. No other computer would be required.  We have tested TNCs attached in this manner on other applications for over a year (daily).  The four UDR56k-4s would form your backbone radios.  AX.25 drivers are already in place to drive the UDR56k-4 at any supported speed including 9600-baud to over 56k baud (with some steps in between).  You would use a CIDR of /29 if these were the only radios on your backbone LAN.

This is an open architure/system so bring your favorite applications (Linux source or Linux ARMEL binaries) to the radio.  If your application is more appropriate to run on another computer, use the UDR56k-4 as a relay device, using an IP interface (wired or wireless).

Further discussion on the UniversalDigitalRadio forum on Yahoo! Groups.



John D. Hays
K7VE
PO Box 1223, Edmonds, WA 98020-1223 
  


On Sat, Jul 6, 2013 at 9:15 AM, Michael E. Fox - N6MEF <n6mef@...> wrote:
(Please trim inclusions from previous messages)
_______________________________________________
John,

I'm glad you're on this list.  Didn't realize that.

I've look and found no "solution" oriented documentation -- i.e. how can I
use the device?  All of the information about the internals, like "socket
interfaces" may have meaning for some.  But, since I don't write protocol
internals, it doesn't help me understand the deployment scenarios.

For example, assume I have four JNOS systems that are currently connected to
each other on a single subnet using a single 440 frequency.  They talk to
each other using IP over AX.25.  I would definitely like to increase the
speed.  But it's not clear to me how I would deploy the UDR56K-4 to replace
the existing 440 radios/TNCs.  What protocol would it run, at what speed?
What would the IP network diagram look like?

If this question is not appropriate for the 44-list, we can move it to your
yahoo group.

Thanks much,
Michael
N6MEF

-----Original Message-----
From: 44net-bounces+n6mef=mefox.org@...
[mailto:44net-bounces+n6mef=mefox.org@...] On Behalf Of K7VE -
John
Sent: Friday, July 05, 2013 11:02 PM
To: AMPRNet working group
Subject: Re: [44net] hardware vs. software

(Please trim inclusions from previous messages)
_______________________________________________
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" <john@...>
 

Michael,

I apologize if my reply wasn't what you expected.  The team has many tasks to complete before release of the UDR56k-4.  I answered with one, efficient, approach -- but it is not the only one.

You wrote:
"For example, assume I have four JNOS systems that are currently connected to
each other on a single subnet using a single 440 frequency.  They talk to
each other using IP over AX.25. I would definitely like to increase the
speed.  But it's not clear to me how I would deploy the UDR56K-4 to replace
the existing 440 radios/TNCs.  What protocol would it run, at what speed?
What would the IP network diagram look like?"

You could continue to do that using the UDR56k-4.  My supposition was that the equipment you currently use is not capable of the speeds available to the UDR56k-4.  If you are going to be replacing the TNCs and 440 radios with a UDR56k-4, then its possible to consider moving the JNOS service right into the radio, saving power and space, which is what I was describing -- however, you don't have to use it in that manner.  (See below)

On Sun, Jul 7, 2013 at 10:20 PM, Michael E. Fox - N6MEF <n6mef@...> wrote:
(Please trim inclusions from previous messages)
_______________________________________________
Thanks John,

But that wasn't my question.  If you re-read my question, you'll see that
the JNOS machines, network, radios, TNCs, etc. already exist.

The question was how to deploy the UDR56K-4 in a 56K bridge configuration on
a shared subnet to replace the existing 440 radios and TNCs.  For example,
some other technologies, like Icom's ID-1, only operate in a point-to-point
configuration (as far as I know).  That's why I asked about the shared
subnet.  Also, merely speeding up AX.25 to 56kbps isn't going to work unless
forward error correction is added.  Hence, part of my question was about
what protocol would be used.

While it was not mentioned in your earlier question, if you wish to run in an bridge manner, you have two options (and possibly a third):
  • Use IP over AX.25
  • Use Ethernet over D-STAR DD Mode 
(in the future there may be a lower overhead protocol).

56kbps (and above) AX.25 can operate without FEC.  It is a matter of path loss and modem BER.  Our modems are designed to minimize BER and one may find that FEC is not required for a given network.
On the other hand, adding a protocol agnostic FEC in the modem is a possibility, exchanging raw bit rate for data correction.  We are interested in this capability and will be looking at use cases for it.

At initial release, we will be delivering those capabilities listed on our information sheet at http://groups.yahoo.com/group/UniversalDigitalRadio/files/insert.pdf 

Since this device is flexible by design, new capabilities can be added at any time, either by us or other developers.  We believe this is a good investment value for our prospective customers.


Everything I've read so far, including your answer below, indicates to me
that the UDR56K-4 is really an experimenter's platform, and the end solution
is left to the user to figure out.  In other words, you're providing a linux
hardware platform with an integrated 440 radio.  That's cool.  But if the
solution I need is a 56K bridge, it sounds like it's up to me to find a
protocol with FEC that is allowed by the FCC, then find the source code,
compile it, test it, then somehow connect that to an IP routing or bridging
configuration in linux.  Am I interpreting the situation correctly?


We will be providing pre-provisioned applications for the UDR56k-4, some of those will be focused on EmComm data users, some on positional awareness users (e.g. APRS), and some on Digital Voice users.  For those applications, its configure and run.

We will also be providing application notes, e.g. "solution 'oriented' documentation" as the product is released.  This will include "bridging" solutions.

Unfortunately, we cannot engineer each user's unique application or solution.  We will provide information that will help various teams and individuals to engineer their own solution.

The intent of this mailing list "UniversalDigitalRadio" is a place to exchange that type of information between users with input from our team.

Right now our team is most focused on delivering a quality product with multiple capabilities.

 
Thanks,
Michael
N6MEF


-----Original Message-----
From: 44net-bounces+n6mef=mefox.org@...
[mailto:44net-bounces+n6mef=mefox.org@...] On Behalf
MIchael,

I don't have time right now to test, but JNOS2 compiles from source on the
UDR56k-4 as does jnosinstaller.  The installer configures the program just
fine.

Barring any unforeseen issues, you should be able to run JNOS directly on
the radio.  If you have TNCs servicing local LANs (e.g. 2 meters, 220, ...),
you can put USB-to-Serial interfaces on the UDR56k-4 and attach the TNCs
with their current radios. No other computer would be required.  We have
tested TNCs attached in this manner on other applications for over a year
(daily).  The four UDR56k-4s would form your backbone radios.  AX.25 drivers
are already in place to drive the UDR56k-4 at any supported speed including
9600-baud to over 56k baud (with some steps in between).  You would use a
CIDR of /29 if these were the only radios on your backbone LAN.

This is an open architure/system so bring your favorite applications (Linux
source or Linux ARMEL binaries) to the radio.  If your application is more
appropriate to run on another computer, use the UDR56k-4 as a relay device,
using an IP interface (wired or wireless).

Further discussion on the UniversalDigitalRadio forum on Yahoo! Groups.

"Michael E. Fox - N6MEF" <n6mef@...>
 

 

56kbps (and above) AX.25 can operate without FEC.  

Not in the real world.  The required S/N and phase error levels required to achieve BER in the 10^-8 range at those speeds is simply not present at many/most sites. 

 

It is a matter of path loss and modem BER.  

 

Of course.  But what’s needed is not achievable to any practical degree at real world sites – at least not around here (Silicon Valley).  We did a lot of testing of AX.25 at 9600.   We tried several radios, several TNCs, measured BER, phase noise, deviation, etc.  In ideal locations, it worked fine.  But in real-world, everyday locations, we found that the increased number of retransmits caused by single bit errors in a packet size of 128 bytes to 256 bytes far, far outweighed the increase in baud rate from 1200 to 9600.  And yes, we set deviation carefully with calibrated service monitors.  Even the Kenwood D710 manual tells you that the received signal needs to be full scale on the meter or else 9600 isn’t going to work well.  And even with a strong enough signal, we have to worry about multi-path issues, particularly in urban environments. 

 

Our modems are designed to minimize BER and one may find that FEC is not required for a given network.

On the other hand, adding a protocol agnostic FEC in the modem is a possibility, exchanging raw bit rate for data correction.  We are interested in this capability and will be looking at use cases for it.

 

Well, if you consider the overall goal of getting as much throughput as possible between two sites, then even if the trade-off was 25%  reduction of the 56Kbps bandwidth in order to get 10^-8 BER, that’s still an enormous improvement over 9600 with no correction.  Seems like a no-brainer.   Add FEC:  I’ll take 8 please.  (Oh, right, pre-orders are closed.)  ;-)

 

Michael

N6MEF