Explaining carriers versus phones

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This page is to develop an explanation to help people who are confused by the separation between carriers and phones, and the different technologies involved.


The question

Some questions being asked:

  • "Which service do we provide"
  • "Which plan do I need"

Carrier/phone separation

The Neo 1973 and Neo FreeRunner are only phones. They are not tied to any specific carrier, nor to any specific plans. If your carrier uses the GSM technology, you can take any unlocked GSM phone which uses the same frequencies as your carrier and use it.

Different technologies: CDMA versus GSM

There are several different technologies used in the cellular world. The two most important are known as CDMA and GSM. These technologies are not compatible; a phone designed for one of them will not work on a cellular network which uses the other technology. Unless your carrier is one of the few who use both technologies, you must chose a phone with the same technology your carrier uses. You could also do the opposite—chose a carrier who uses the technology of the phone you have or intend to buy.

The Neo 1973 and Neo FreeRunner work only on GSM networks.

Technical details: cell phone frequencies

There are several different radio frequency bands allocated for cell phone use. Each carrier uses one or more of them; which frequency bands are available depends on the country the carrier is in. A phone will only work with a carrier if it can use the frequency bands the carrier uses. Most phones can use more than one frequency band; dual band, tri band or quad band phones are very common. A quad band phone will work with almost any GSM network in the world.

The Neo 1973 and Neo FreeRunner are both tri-band GSM phones. The Neo 1973 uses European frequencies (900/1800/1900). The Neo FreeRunner comes in two versions, one with European frequencies (900/1800/1900) and another with North American frequencies (850/1800/1900).

Technical details: SIM

The reason you can take any unlocked GSM phone with suitable frequency bands and use it on your carrier is that your cellular phone line is not tied to your phone, but to a small (25 mm × 15 mm × 0.76 mm) miniature smart card, usually hidden behind the phone's battery. This card can be removed and inserted in another phone, which will then be able to use the phone line.

The Neo 1973's SIM card slot is hidden behind its battery.

Technical details: subsidy lock

Some phones, usually phones bought together with a carrier's service plan, are locked, and will work only with SIM cards from the same carrier (or sometimes only with one specific SIM card). You can still, however, remove the SIM card and use it on a different unlocked phone (or a locked phone from the same carrier, if the lock is not specific to the SIM card). Usually only phones sold by the carrier itself are locked, and some carriers allow you to ask for your phone to be unlocked (usually either asking for a fee or after some time on your contract).

The Neo 1973 and Neo FreeRunner are unlocked phones.

In some cases, transferring the SIM from a 3G phone to a non-3G phone will result in the SIM eventually being barred by the network. 3 in the UK are reported to do this, as they use Orange's network to provide coverage where they do not have it, which means that GSM-only phones are significantly more expensive for them to provide service to.


You need a plan from a GSM carrier to use your Neo 1973. Only buying a Neo 1973 will not give you the ability to make phone calls (with the possible exception of emergency calls), since it does not come with a SIM card. You need to have both.


Some useful analogies:

  • A Neo 1973 or Neo FreeRunner is like a conventional fixed phone, and the wireless carrier is like a conventional phone company. Your phone service is independent from the phone device; you must have both, but you can replace either independently.
  • A Neo 1973 or Neo FreeRunner is like your computer, and the wireless carrier is like your Internet connection. While you can buy your computer with an Internet connection plan, they are most of the time completely independent.
  • A Neo 1973 or Neo FreeRunner is like a TV receiver, and the wireless carrier is like the over-the-air public TV network.
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