What Constitutes an Unlocked Phone?

If it was unlocked you would know. Usually you would purchase an unlock code or buy the phone unlocked. You wouldn't have bought an unlocked phone if you weren't looking for one. The phones you buy at a specific carrier like AT&T or Verizon etc are not unlocked. They are locked to that carrier.

 

The phone even after being unloacked needs to have the antenna to receive the cell phone signals. I had a Verizon phone and they are unlocked but the problem is because I original got the phone from Verizon it only had the antennas to work on the Verizon network..

I have been buying thses cheaper Moto G5 Plus phone. It's unlocked and the big thing it has all the antennas ! I can put any SIM card in the phone and run on Verizon ATT or T-MOBILE I think Spint also. So now I got Straight Talk sim card running on the Verizon network. I tried T-Mobile did not like the coverage.

I got the 64 GB memory, fingerprint reader to unlock the phone. Only thing this cheap phone is missing is NFC for swipe and pay at cash register and wireless charging.

If you can see it a unlocked phone but also work on every carrier
www.motorola.com/us/products/moto-g-plus#Specifications

 

Unlocked phone means a Carrier branded device i.e. verizon, that has been allowed (unlocked) to be placed in service on other (usually) minor carriers.

My case: I have a Verizon Samsung Note 4, that I use on Pageplus Cellular.

I paid $150 cash for the device, and reconnected it to a $55/mo unlimited plan - no contract, and guess what, It still uses verizon towers.

 

Straight Talk seems to be claiming a new Unlimited data and talk and text for $55. I was paying $55 for 15GB and unlimited talk and text. So I'm interested to see if what I'm reading is real or some hidden scam. It's says their new Ultimate Unlimited date and talk and text $55 a month. Straight Talk has Verizon and AT&T and T-Mobile.

 

If I was trucking I would have AT&T they have good coverage and am unlimited everything plan. Right now I'm only able to afford Metro PCS

 

If you bought your phone through a carrier and are under contract it's likely locked. If you're out of your contract you may be able to get a code from them to unlock it, but I wouldn't hold my breath with Verizon.

 

That phone is probably still locked. You just avoided having a contract.

Who is the sim provider? I.e. whose providing the plumbing?

 

Antennas have nothing to do with it, at least with most name brand phonea. It's a software/sim card thing. Most Samsung phones after the Note/S3 had a modem for every US carrier built into the motherboard from the factory, up thru 4g LTE...some even had the 4g LTE+ (Verizon called it XLTE). All that is needed is a software reflash that turns on the proper circuit to the correct modem for a different carrier, and their sim card. I believe I read that the Note 6 had access to either 11 or 13 modem frequencies...so it would work pretty much anywhere in the world.