Questions on Mobile data connections and average latencies/jitter etc.

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paradoxsm

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#7563 24-Apr-2006 19:07

Does anyone know first off if moving about cellsites affects your mobile data connection while it re-establishes a connection or whether it's just a seamless merge and doesn't affect a continuous stream of data...

Does anyone know if either UMTS, EVDO, 1RXTT had problems with jitter as this is also very important.

I am doing some serious testing in the next few days so any info would be a great help!

I once had high hopes for Woosh but this locks onto one cellsite so when it's out of range, it just drops. Kinda pointless.
I'm trying to decide if with all factors* taken into account, I'll stick with Vodafones UMTS or Telecoms EVDO (unless the latter is free ;-)

*(I know Telecoms is faster, Vodafone have handsets, blah blah blah So I don't want yet another "T'Com VS V'Fon" forum)

PS: we need a "general Mobile" forum to put posts like these in.

Jama

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#33789 24-Apr-2006 19:30

CDMA has soft handover - you acquire cell site B before you handover from cell site A. I have seen no discernable difference in latency or packet loss - mobile vs stationary.

1xRTT - only hands up to EVDO when dormant
EVDO - hands down to 1xRTT when active and can take a few seconds (if you were pinging you would see a timeout)

timbosan

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#33791 24-Apr-2006 19:35

I cannot help with the UMTS, EVDO, 1RXTT (sorry!) but I know GPRS has seemless handovers, I have never lost a signal whilst moving, except if there is no signal at all!

Are you going to let us in on what you are testing for? It all sounds very interesting!

Jama

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#33793 24-Apr-2006 19:38

GPRS uses hard handover. It can be quite abrupt and it can cause a delay.

paradoxsm

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#33795 24-Apr-2006 19:42

Cheers, Jama great info, Yes have found GPRS while it keeps connection takes about 10 seconds to re-establish anything, ins rather reliable (better than phone call GSM handovers!) but ultra slow for latency and throughput..

CDMA all uses the 800MHz band am I correct? This is probably enough of a feature in itself, Means antenna design is easy as (025 antenna's are a-plenty) as it does not need dual frequencies.

Jama

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#33796 24-Apr-2006 19:46

All 800MHz and in the same part of the spectrum. Antenna's are the same for 1xRTT and EVDO. It does pay for EVDO to have antenna diversity ( Rx and Rx/Tx).

paradoxsm

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#33798 24-Apr-2006 19:54

Well WHAT will I use it for.....

VoIP (not just italk and similar IF it will function but also conference calling via an office/network of work vans)

Video Conferencing and live broadcasting from remote areas (Jama, What is EVDO's upload speed?) UMTS does not cut the cheese here, 40Kbps (64Kbps maximum) was too just too jerky and grainy and coverage is an issue.

Remote site monitoring using some data connection for high res images and low-res (352x288) video, Already running images over GPRS, we also tried PXT but some reason the uploads were even slower! (Class 10 GPRS) 2T 3R

A "Mobile webcam" which if we can get it to work will follow someones tour throughout the country. Need to get hands on a harrier and see if something can be written to use it soley as a broadcasting handheld camera.

Just playing about at present aside the remote monitoring but still cool.

Apple TV

Stream your favourite shows now on Apple TV (affiliate link).

sbiddle

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#33806 24-Apr-2006 22:34

Sounds like you obviously need to get a job, you obviiously have far too much spare time on your hands to be playing with VoIP stuff all day!! :-)

paradoxsm

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#33809 24-Apr-2006 23:08

Looks like from next week I am again full time empolyed hence the sudden rush!,,,, Watch this space.

Been doing contract work for the past 8 or so weeks hence travelling all over sth island last week and getting to fiddle with some cool stuff. (what a glorious trip it was :-)

paradoxsm

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#34078 27-Apr-2006 02:58

Winner of Mobile data tests for my purposes.................... Telecom EVDO. hands down.

Speed was quite a bit higher.

upload seemed just as fast as download, no 64k upload choke like UMTS

The 800 MHz had way better building/hill penetration and wider general coverage than the 2GHZ UMTS.

Dropping down to 1RXTT from EVDO was fast, Automatic.

Cellsite EVDO - EVDO "Handovers" were seamless with Telecom, Got a bit of jitter from UMTS.

Battery life was better.

mobile broadband alerts available to avoid those nasty overage surprises

The bad....

Poor selection of devices (good devices, just not many of em and expensive) Data card, Sanyo, Two HTC PDA's

Not transferable to another phone without having network based change done, Wap not included (but is on PDA's through PIE's wap support)

I wish they had released this prior to my Sth Island trip, GPRS was just painfully slow, reliable old horse, but sl ow ow w

Telecom, Yellow is "3G" Coverage Vodafones, Yellow Ochre is "3G" coverage.
Telecom EVDO

I'm in no way bagging Vodaone, it was their only upgrade path and aside from the coverage, they have done a good job of it, "3" in Australia's wasn't nearly so rosy, All sorts of plagued problems and other hideous rubbish.

For the time I have used Voda 3G, I have been impressed, it works close to it's theoretical maxumum 384Kbit almost all of the time.

Now I better get some sleep, I'm tired of dropping people off at silly hours to catch planes!, I should have never sold the 2-seater MR2's, Now i'm a Taxi with my 4 door saloon, I at least had an excuse before

nob

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#35626 13-May-2006 00:26

I know with Edge tech. it is completely seamless between edge and gprs.

sbiddle

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#35629 13-May-2006 08:01

nob:
I know with Edge tech. it is completely seamless between edge and gprs.

EDGE is still the GSM network so that's not surprising. UMTS to GSM means changing networks.