Author Topic: Which connection speed necessary - practical knowledge  (Read 4802 times)

DL1AKP

  • Newbie
  • *
  • Posts: 2
    • View Profile
Hello folks,

I just want to know what internet connection speed is necessary to work with?
Can it work via the UMTS net, or even GPRS?

What did you expereience at wich speed?

Thanks fo reading - and answering

Andy, DL1AKP

IN3ASW

  • Newbie
  • *
  • Posts: 14
    • View Profile
    • Email
Re: Which connection speed necessary - practical knowledge
« Reply #1 on: 2011-09-04, 12:21:42 »
Hi,
althought not using GPRS or UMTS, my "small" HiperLan 5Ghz WIFI ADSL link @ 1Mb/256Kb with a Linear 12bit/8Khz Codec at the Radio site works perfectly. Guess that with slower links you need to reduce the audio quality.

73's

Gianni

KP4TR

  • Jr. Member
  • **
  • Posts: 80
    • View Profile
    • Email
Re: Which connection speed necessary - practical knowledge
« Reply #2 on: 2011-09-06, 03:08:41 »
My DSL connection in Puerto Rico varies from day to day. When it drops below 150kbps using audio quality 2, audio gets choppy. Below 120kbps, it is not useable and the solution is to reboot the DSL modem remotely. I get typical speeds of 800Kbps down/250kbs up and that's perfect. Downlink speed is never and issue on my end, its the uplink speed that varies.

dj0qn

  • Hero Member
  • *****
  • Posts: 2223
    • View Profile
    • DJ0QN / K7DX
    • Email
Re: Which connection speed necessary - practical knowledge
« Reply #3 on: 2011-09-06, 09:13:04 »
Just a general tip from my side: Just because the RRC box allows one to run a higher
quality codec doesn't mean that one has to use it. I have installed several stations and
have kept the codec at 0 to minimize the bandwidth used. For normal SSB and CW work,
this codec is more than adequate and will allow the flexibility to work with unknown or low
remote bandwidth without audio drops.

Appendix A of the manual lists the codecs and bandwidth, so you can see the effect of reducing
the codec quality. I would think a higher bandwidth would only make sense with FM, ESSB or when
you have known high-speed fixed control and radio bandwidths.

Remember also that this is doubled, up and down! Most DSL lines are asynchronous and have a lot less
bandwidth going up than down, but the internet provider usually only advertises the down speed. You
need therefore to take into account that the bandwidth used by RemoteRig  is the same in both directions.

A corollary is the serial ports sent over the RRC, including CAT. It is not always necessary to run them
at 57,600 bp/s! When possible, reduce them down to 4800 bp/s and reduce your bandwidth that way.

73,
Mitch DJ0QN / K7DX


DL1AKP

  • Newbie
  • *
  • Posts: 2
    • View Profile
Re: Which connection speed necessary - practical knowledge
« Reply #4 on: 2011-09-06, 14:22:34 »
Hi guys!

Thanks a lot for answers, especially Mitch! That helps a lot.
I do not need a good audio quality, because I work only CW.

So most important for me is the timing of CW and the control of the serial port for the pa.

I think, I should test connecting speed at the desired location first with different providers and then
make a decision.

Anyway, If someone has specific configuration details usefull for CW work, I would be glad to know it!

73 de Andy, DL1AKP