3G datacards question.

FRM

How do 3G datacards work ??? Sorry for such a silly questions but wondering if I could use them to make VOIP calls.

Not sure what the script also is with download/upload limits.... anyone give me a quick beginners guide ???

crawler

PCMCIA type card or dongle - acts as an Ethernet NIC
Latency typically 150ms or higher (120ms or lower is best for voip)
NOT always on so not good for incoming VOIP unless you are connected
Limits depend on provider and package selected
Speeds typically 300kbps to 1mbps on average in "real world"

that seem about right to all?

shane_by

Just one teeny weeny qualification: the speeds quoted above are indeed 'real world' - if you are in a 3G area. I am using a 3 Datacard in a 3G area right now and, according to speedtest, my download speeds are about 1.3mbps, which is fair enough. Alas, I live in a non-3G area so my connection roams onto the Vodafone GPRS system. I typically get speeds of around 50kbps, which is far, far short of broadband but at least it's faster than my dial-up; also, I find downloads are more consistent than dial-up; and I'm not gettin the ear chewed off me for tying up the phone line all evening!

Jimoslimos

I'm in england at the moment and have a T-mobile datacard. Being close to London ( a 3.5G area) my connection speeds are between 600kbps and 1.8Mbps.

Don't know about voip since my provider has banned it on my package :mad:

Someone mentioned the latency being a little too long for voip calls. I'm no expert but could someone tell me whether this is a limitation of the technology or is it set by the service provider. I can't imagine one particular reason why companies like vodafone, t-mobile, o2, etc., would not want you making calls over voip:rolleyes:

crawler

Ideally you sohuld have latency of sub 120ms for "voice" to work well - otherwise you suffer lag and echo etc - that said some of the newer rate adaptive codecs cope with this a bit better.

the latency of 3G is due to the way the air interface works - xCDMA or CDMA variants are really circuit switched environments adapted to cope with data but there is no free lunch.

Under 3GPP2 LTE (Long term evoloution) - OFDMA is utilised which brings latency back to more realisitc levels.

Regarding mobile operators banning VOIP- most mobile data revenues still come from voice but I guess this will change in time as MO's move to flat fee voice and data models and natively support VOIP as a service offering.

FRM

so after all that techno babble... I'd say No is the short answer ???

crawler

FRM wrote:

so after all that techno babble... I'd say No is the short answer ???

Well - I think "kinda" is more accurate.

VOIP would probably work - it just may not work very well just yet.

FRM

lol...... might have to purchase and try it !!!

I'm running out of options with no landline for the foreseable months....

crawler

We will prpbably be heading that direction (longford?) after Mullingar - but again that's a few months off...

godskitchen

I have both the Vodafone and Three packages.............i use VOIP (Skype) on both with NO problems, i call the UK and the US most nights and there is very little lag.

People always comment on how clear the phone call is and when i tell people i am calling from the computer they are shocked.

So in answer to your question from someone who uses the service, Yes you can make VOIP calls.

If you like i could call you on a land line to show you how it sounds, but thats not really needed, get the service, i dont htink you will be sorry.

FRM

Thanks very much on all the information.... one last question is with regards to the 3GB data limit..... does VOIP affect this ??? In other words does it eat into the 3GB limit on THREE ???

Sponge Bob

voip is not that heavy on bandwidth,

Be aware that 3G carriers often have conditions banning voip or skype ( or allow skype and not standard voip) so read them carefully.

I suspect 3 allow skype specifically meaning they do not allow standard voip which is sip or h323 with a g.7nn codec but you read the terms and conditions as they do change periodically and even retroactively in some cases

3 customer care is awful .

godskitchen

Sponge Bob wrote:

3 customer care is awful .

You are too kind...............the customer care is SHOCKING!

I am still trying to talk to someone about a faulty mast................which i first reported 3 weeks ago!