How 3G Frequency Compatibility Works / Why Your Unlocked Phone Doesn’t Get 3G

Ok, so I’ve realized that a lot of people see all the cool phones over in Europe, buy them here in the States for use on T-Mobile or AT&T (myself included) and all is fine and dandy but then they wonder why they don’t have 3G when on the box of the phone it clearly states 3G enabled…

I wanted to explain why this happens.

So basically 3G is dependent on two things; what frequencies the phone has built in that it can see and what frequency the phone company you want to use is projecting their 3G network on.

Let’s start with the latter factor. Here in the US, we have two GSM carriers that both have 3G; AT&T and T-Mobile.

AT&T projects their 3G network on 1900mhz (and recently started projecting on 850mhz as well).
T-Mobile projects their 3G network on 1700mhz (and we believe owns 2100 but isn’t using it yet, see 3G Revelation post for more details on that).
Most European phone companies (where most unlocked phones are made for) use 900mhz or 2100mhz to project their 3G networks.

Since most unlocked phones are made for European use, they have 2100/900mhz receivers built in. So if you are using that phone on a network that uses either 2100mhz or 900mhz, you’re phone will be able to see the frequency and get 3G data.

On the other hand, when you bring that phone over here to the States and try to use it on T-Mobile or AT&T’s 850/1700/1900mhz 3G networks the phone simply cannot see these frequencies and can only get up to EDGE connectivity. (The phone works fine, but you will not get 3G data speeds).

So bottom line, when you buy an unlocked phone for use here in the US, make sure that it says in the specs for 3G (sometimes called HSDPA or HSPA) that at least one of the frequencies match your carrier’s 3G frequencies if you want to use 3G. Otherwise, get one with Wifi and hope you can find some free hotspots around…

Now, when you buy a phone from your specific carrier here in the US (as most Americans do) they had that phone specially made for them by the manufacturer (and branded with their logos etc.) and had the manufacturer put their 3G frequencies in it (sometimes they leave 2100mhz as well for those people who want to goto Europe with their phone).

Now, this brings me to question something though…
Why wouldn’t a manufacturer, who knows that a lot of people won’t buy a phone if it doesn’t get 3G where they live, just put ALL the 3G frequencies in everyphone they make (called PentaBand 3G for the 5 frequencies; 850/900/1700/1900/2100mhz)? It can’t cost that much more to put the other 2 or 3 antennas into the phone and it would open their phone market up to anyone in the world (and also stop them from having to make differing versions of the phones for just that reason, i.e one for North America, one for Europe, and one for Asia).

Anyone have any better idea than I as to why the manufacturers won’t do this?


  • http://blog.bongeek.com Mudassir

    100% with you!

    Here is the million dollar question:

    When we will have iPhone with PentaBand 3G ?

    I so wish I can have iPhone 3GS running on T-Mobile 3G Network (not on Edge, and I know it can be run on T-Mobile but only on Edge).

    Come on… iPhone 3GS PentaBand, anyone?

    • http://www.theunlockr.com TheUnlockr

      Hello Mudassir,

      Ha, maybe after AT&T’s contract runs out. Until then if they put Pentaband in it AT&T would see it as “enabling unauthorized carriers features” blah blah etc.

      • BostonBoy

        Hi,

        If you buy any unlock phones in the U.S you should look at these informations:

        GSM: 850, 900, 1800, 1900GSM – Global System for Mobile communications. A world standard for digital cellular communications using narrowband TDMA (Time Division Multiple Access), which allows up to eight calls at a time on 800 MHz and 1800 MHz frequencies. Introduced in 1991. Is the standard most commonly used in Europe and Asia, but not in the United States. GSM phones use a Subscriber Identity Module (SIM) smart card that contains user account information. Any GSM phone becomes immediately programmed after plugging in the SIM card, thus allowing GSM phones to be easily rented or borrowed. SIM cards can be programmed to display custom menus for personalized services.GSM provides a short messaging service (SMS) that enables text messages up to 160 characters in length to be sent to and from a GSM phone.850, 900, 1800, 1900GSM – Global System for Mobile communications. A world standard for digital cellular communications using narrowband TDMA (Time Division Multiple Access), which allows up to eight calls at a time on 800 MHz and 1800 MHz frequencies. Introduced in 1991. Is the standard most commonly used in Europe and Asia, but not in the United States. GSM phones use a Subscriber Identity Module (SIM) smart card that contains user account information. Any GSM phone becomes immediately programmed after plugging in the SIM card, thus allowing GSM phones to be easily rented or borrowed. SIM cards can be programmed to display custom menus for personalized services.GSM provides a short messaging service (SMS) that enables text messages up to 160 characters in length to be sent to and from a GSM phone.850, 900, 1800, 1900UMTS: 850, 1900, 2100UMTS – Universal Mobile Telecommunications Service, also called WCDMA, is a 3G (Third Generation) packet-based transmission of text, digitized voice, video, and multimedia at data rates up to 2 Mbps. It is based on GSM standard and is supported by major standards bodies and manufacturers.

  • Gbdrewit

    It seems to me that they can sell a phone for more money if a carrier has to pick it up, add frequencies, brand it, and order a certain amount than if all phones were essentially world phones and could be bought and sold by anyone, anywhere… right?

    • http://www.theunlockr.com TheUnlockr

      Hello Gbdrewitt,

      The manufacturer’s sell the phones to carriers at MUCH less than they sell them one by one to the unlocked market (makes sense since if a carrier here in the US picks up a phone they could buy ALOT of them at one time from the manufacturer).
      But I’m talking about the phones that are sold unlocked already, meant for use on any carrier. Why don’t they have pentaband 3G so all carriers can get 3G, why pick and choose what 3G frequencies to put in the phone?

  • earWax

    I have a question… Why can’t they manufacture units that have a “frequency slot” like where you put your SIM or Micro SD Card? Then you could manufacture the units without regard to frequency. Then you have the “frequency crystal” come with the unit like the SIM comes with the unit?

    Just a thought…

  • nepalese

    I need some advice. I own a mytouch with hero Rom and it works great besides online video streaming like the real Hero is capable of. so I wanted to get a Hero and now I have hold myself back because of HTC Leo. My question is, can either one of these phones run 3g speed on TMobile network? Is it worth the wait for Leo or just get the Hero? I also like Android over WM and will most likely use a hero Rom for Leo. Any suggestions?

    • http://www.theunlockr.com TheUnlockr

      Hello Nepalese,

      1. Neither phone will get T-Mobile 3G (they do not have 1700mhz built in so won’t work).
      2. HTC Leo will not run android or Hero (it runs Touchflo though which is similar to the Hero UI but its on top of Windows).
      3. There is an Android device coming out from HTC that we believe will be an Android version of the Leo. Not sure when it comes out but that might be worth it, up to you. (HTC Dragon).

  • nepalese

    Thank u for the quick reply. Will keep an eye on the dragon and see if its gonna have similar specs as the Leo.
    What if TMo starts using the 2100mhz frequency? Will we get 3g for these devices?

    • http://www.theunlockr.com TheUnlockr

      Hello Nepalese,

      K if you see anything let me know.
      Ya, that is the million dollar question, we won’t know until they launch it. Read the 3G Revelation post I did a while back…

  • bogdi1988

    I think it is about the cost. If it has only a few bands, then the company can charge different prices in different countries. This would stop people from buying the phone from a cheaper country and exporting it everywhere else… my 2c

  • Neo

    Hello Nepalese,

    Yes, please read the “3G Revelation” post he did a while back. thx. :P

  • sean

    Here in Australia we use 850 mhz with telstra 3g optus & vodafone use 900 mhz & 2100 mhz for 3g and 2g 900 mhz and 1800 mhz and the phones are not locked on any network on postpaid contract and prepaid phones are locked and they can be unlocked with a fee about around au$50 some people can unlock them without paying anything. usb 3g modems are locked and they can be unlocked i unlocked a usb modem by putting another provider sim in it and it unlocked it was very easy and here in australia the cell phone providers cant stop you to unlock the cell phone or usb modem and its the rules by the telephone athority and ive always been able to unlock them

  • K

    I believe it’s actually really difficult technically to put antennas of different frequencies on the same device. That’s why the phones only come with a few frequencies each.

  • Pivo

    Had I found your smart post earlier, I could have saved myself an hour or two of research in the last few days.

    What you point out is on the money – and drives me crazy: supposedly people pay $400 – $900 (or Euros) for an unlocked smartphone, but they are the ones who do NOT travel internationally? Yeah right. The manufacturer’s policy is major hubris.

    Only by accident, I saw that my Swiss-sourced Nokia 6120 with HSPA 1900/2100 works fine on US t-mobile in 3G (1700/2100, the latter being the overlap). So depending on your carrier, a EU phone may work on 3G in the US and vice versa. Or it may not if you forgot to check those damn Mhz. Bad Mhz, bad!

    Interesting sidenote: ebay Germany (pop. 80m) has more unlocked HTC Legends or iphone 3Gs for sale than ebay US with 300m pop.

  • http://www.youtube.com/jeromeo1980 Jeromeo

    The only phones in the world that have Penta-Band (Europe/Asia/NorthAmerican T-Mobile/AT&T) are the Nokia N8, Nokia C7, and the Nokia E7…

  • Jonsmittt

    T-Mobile (US) 3G Frequency Compatibility

    The way T-Mobile list their 3G frequency (1700/2100) is really terrible and has caused a lot of confusions!

    TM (US) operates on UMTS Band IV – 1700 unlink and 2100 down-link.

    Most oversea phones are UMTS Band I – 2100 up/down and/or UMTS Band VIII – 900 up/down.

    Therefore, Band I -2100 is NOT compatible with Band IV – 1700 up 2100 down.

    Another word, most oversea phones are NOT compatible with TM (US) 3G data band.

  • Afrocuban510

    the truth is when I was using a unlocked omina 2 with t-mobile it would jump back in for from edge to 3g but it would only say G on the screen… but when I was using AT&T with the same phone I did get 3g so I guess it depends on the unlocked phone

  • Junkmail1000

    It’s not only a couple more antenae but also some hardware/firmware for frequency division/multiplication to obtain the additional frequencies. I agree with you the cost to add would be insignificant. The reason they do it is for commercial reasons. The operators do not want them to have a competitor’s frequencies because when a contract expires it will be more difficult for a user to move to the another carrier. For the same reason operators have “cripled” many phones with built in GPS chip to allow positioning with tower traingulation and not sattelite positioning.With exception of Nokia all manufacturers exclude the free sattelite navigation so that a user will have a “data plan” that will cost more but provide additional revenue to the operator. Simply put, operators make more money and handset manufacturers have loyalty to the operators and not to end users except for Nokia.

  • Will8840

    My major issue is i would like to get a dual sim phone. One sim for work one for home. This device needs to be 3g and android. This is a problem i am on at&t. Any ideas?

    • Estepinchecorreo

      Yes, buy a chinesse phone. 

  • http://www.facebook.com/jonathan.partlow Jonathan Partlow

    Why isnt T-mo USA using 2100 yet?

    • Jarrod

      They do use it but its only for downlink, and uses 1700Mhz for uplink only

  • Trang Guy

    Do you realize that this article has been copied here: hxxp://blog.tinydeal.com/2011/10/13/how-3g-frequency-compatibility-works/

  • Seveboyd28

    if u buy a nokia n8 or nokia n9 they have all five frequencies built in. so they can 3g every where