Technical Or Selling Issue: 3G 850 Versus 900

[vagabond48]

This question is for techies not guessers. Thanks

I started using an air card just 6 months ago and before buying it, I researched the 3G frequency requirements to buy the right one for DTAC. The cost was well under 1000B so who cared. I just recently bought my 1st smartphone and was surprised that I had to get the 850/2100 for DTAC.

Why can't they have both frequencies in one unit so that you could change to a different phone carrier (in Thailand), without having to buy another phone or air card. My basic question is whether this is due to a technical limitation or do the manufacturers want you to buy 2 phones.

[happysanook]

Different companies pay for the rights to certain 3G frequencies. AIS and DTAC just happen to have different frequencies (the reasons buried in corporate and government bureaucracy), much like ATT and T-Mobile in the US. Though in the US ATT and T-Mobile are currently working out deals where users will be able to roam on each others' 3G frequencies.

This boils down to phone manufacturers being cheap. They can save a few bucks by not including additional 3G radios as well as forcing those who need it to pay a big premium for "global" multi-band 3G phones. Most people won't need it, so most people aren't bothered by the fact.

[SpaceKadet]

850/900 are always supported on all modern handsets, as these frequencies are used for standard voice communication.

2100 spectrum is for new 3G communication so it might not be supported on all handsets.

The aircard is just a subscription to the service provider. It will use whatever frequencies has been allocated to your particular provider.

The new 2100 spectrum will be better for data services since it is less crowded and higher frequency wiil ensure higher data throughput.

Higher frequency however, will also mean it will be easier disrupted by rain and foliage. It will work great in the citied with good cell coverage, but probably

not so great in the boonies...

[thaicbr]

This question is for techies not guessers. Thanks

I started using an air card just 6 months ago and before buying it, I researched the 3G frequency requirements to buy the right one for DTAC. The cost was well under 1000B so who cared. I just recently bought my 1st smartphone and was surprised that I had to get the 850/2100 for DTAC.

Why can't they have both frequencies in one unit so that you could change to a different phone carrier (in Thailand), without having to buy another phone or air card. My basic question is whether this is due to a technical limitation or do the manufacturers want you to buy 2 phones.

OP. There are MANY phones that have 900.850 and 2100 3g here in Thailand starting from about 6,000b up. Check out GSM arena.com for English and Siamphone.com Thai (some Thai brands are not on gsmarena)

My tip for low cost decent phones are the I-mobile Q style and IQ series. From about 3995b up to 9995b depending on spec.

sent from my Q6

[lomatopo]

There may be some confusion here re: GSM frequencies and 3G frequencies.

Most phones, and modems, support quad-band GSM for standard GSM voice, text and 2G data (GPRS/EDGE) on 850 / 900 / 1800 / 1900 MHz.

The 3G frequencies used here are 850 MHz, (DTAC/CAT/TrueMove H) 900 MHz (AIS) and 2100 MHz (TOT, for now). 850 MHz is a bit of an odd duck, but since CAT and DTAC both have that spectrum they rolled out 3G on those frequencies.

In some cases there is no need to include both 850 and 900 as there are so few markets where those overlap, hence you see mostly one or the other in phones and modems. More expensive handsets throw in a more expensive quad- or penta-band baseband IC as much to sell it as a "world" phone as to keep SKUs to a minimum.

I guess, to answer your question, product cost - and all that goes with it - may be the main reason. It is not some nefarious plot to get people to buy more phones.

[monty]

And normally should become moot anyway, as over the next months all 3 main providers will be rolling out 3G on 2100 MHz, now with the licensing looking finally to be sorted out.

Pretty much all 3G capable devices should handle 2100 MHz.

Sent from my GT-I9001 using Thaivisa Connect Thailand mobile app

[lomatopo]

Re: 2100 MHz, for some providers whose concessions are ending sooner rather than later (TrueMove - 2013; AIS-2015) the switch to 2100 MHz may work out, assuming the "old" spectrum actually gets returned to the NBTC. DTACs concession lasts until 2018 so some expect them to re-farm 850 or 1800 to LTE, keeping high ARPU customers there, and grabbing new customers on 2100 MHz..

Bottom line, this whole frequency matching thing may come back as LTE gets deployed: Apple has at least two GSM/SIM LTE models so you'd have to pick the "right" one for your provider.

[reflectionx]

there are five bands for 3G (UMTS/HSPA) communication:

850, 900, 1900, 2100 and AWS (1700 for uplink/2100 for down link)

When you buy a 3G device, a penta-band device would support all 5 frequencies - it would work on 3G virtually anywhere in the world.

Use GSMarena's tool to search for device that support the frequencies that you estimate you will want your device to support:

http://www.gsmarena.com/search.php3

Just check all the bands you want your device to support.

These are all pentaband devices on the market today:

http://www.gsmarena.com/results.php3?sName=&idMaker=0&chkUMTS850=selected&chkUMTS900=selected&chkUMTS1700=selected&chkUMTS1900=selected&chkUMTS2100=selected&idAvailability=0&YearAnnounced=0&nPriceLow=0&nPriceHigh=0&idCurrency=0&idFormFactor=0&idSIMType=0&idDualSIM=0&idQwerty=0&HeightMax=0&WidthMax=0&ThicknessMax=0&WeightMax=0&idOS=0&idOSVersion=0&idOSWhen=0&nminCPUMHz=0&nCPUCores=0&nminRAMMB=0&nminInternalStorageMB=0&idExpansionCard=0&idDisplay=0&nminDisplayX=0&nminDisplayY=0&nmaxDisplayX=0&nmaxDisplayY=0&fminDisplaySize=0&fmaxDisplaySize=0&nPixelDensity=0&idDisplayTech=0&idTouchscreen=0&idAccelerometer=0&idGyro=0&idCompass=0&id35mm=0&idCamera=0&idCameraFlash=0&idVideoRecorder=0&idSecondaryCamera=0&idGPS=0&bWLAN=0&idNFC=0&bEDGE=0&bGPRS=0&idBluetooth=0&bIR=0&bEmail=0&bWAP=0&bJava=0&idRadio=0&bMMS=0&idRingtones=0&sColor=&StandBy=0&TalkTime=0&sFreeText=

[reflectionx]

Re: 2100 MHz, for some providers whose concessions are ending sooner rather than later (TrueMove - 2013; AIS-2015) the switch to 2100 MHz may work out, assuming the "old" spectrum actually gets returned to the NBTC. DTACs concession lasts until 2018 so some expect them to re-farm 850 or 1800 to LTE, keeping high ARPU customers there, and grabbing new customers on 2100 MHz..

Bottom line, this whole frequency matching thing may come back as LTE gets deployed: Apple has at least two GSM/SIM LTE models so you'd have to pick the "right" one for your provider.

According to GSM Arena, Thailand will use 1800 and 2300 for LTE:

http://www.gsmarena.com/network-bands.php3?sCountry=THAILAND

BE CAREFUL IF YOU BUY LTE DEVICE FROM APPLE NORTH AMERICA - IT WILL MOST LIKELY NOT WORK ON LTE SPEEDS IN THAILAND. Looks like lots of the LTE phones will have issues roaming on LTE frequencies.

For example, USA is running LTE on LTE 700, LTE 1700, LTE 1900, LTE 2100

Canada - LTE 1700, LTE 2100, LTE 2600

Germany - LTE 800, LTE 1800, LTE 2600

LTE interoperability will be a mess ...

Also, using LTE drains my battery 2 times faster than on 3G

[reflectionx]

Also, using LTE drains my battery 2 times faster than on 3G

But who gives a shhhh, LOVE those 50Mbps speeds :intheclub: