huggy59
Active Member
T-Mobile is a big GSM provider, and AFAIK the SIM card was originally developed to be used on a GSM network and its phones. I went with GSM years ago when I was given a phone to try at work while we were looking for "world phones". At that time, GSM was the most popular standard in Europe and other areas, and just starting to come into the US. I started way back with Omnipoint, then they became VoiceStream, and finally T-Mobile. All GSM and all had SIM cards. The company I worked for was looking for phone that could go fromt he US to Europe without requiring a change of gear.
The SIM card also contains some memory, which in some cases can be used for storing phone numbers (phone book), SMS messages, and other info depending on the phone.
Also, in addition to the SIM card for GSM networks and the capability for a phone to have different network signaling systems (GSM, CDMA, etc.), there is also the now 4 frequency GSM bands to deal with. I had a Treo 270 in South Florida (well, I still have it here) that is a 2-frequency phone (900MHz and 1900MHz), but when I moved to Maine, I found the local GSM network here used another frequency, so I had to get a different phone. I ended up getting a Treo 600, which supports all 4 GSM frequencies: 850MHz, 900MHz, 1800MHz and 1900MHz.
Of course, now I wish I had the extra features that are on the Treo 650... mainly Bluetooth, a removable battery, and MP3 playing.
The one thing that I wish they made for the Treo phones that I haven't seen yet is a good car system. I have a Nokia 5190 phone and installed a complete system in my truck - snap the phone in the cradle and it locks in, connects to a mic, speaker, handset, power and antenna in the car. It can even mute the radio when the phoen rings, and it auto-answers in the car so you don't have to touch it at all. Nice! Wish all phones had a similar system. Alas, I can't use that phone here in Maine - wrong frequency!!!!! :-(
The SIM card also contains some memory, which in some cases can be used for storing phone numbers (phone book), SMS messages, and other info depending on the phone.
Also, in addition to the SIM card for GSM networks and the capability for a phone to have different network signaling systems (GSM, CDMA, etc.), there is also the now 4 frequency GSM bands to deal with. I had a Treo 270 in South Florida (well, I still have it here) that is a 2-frequency phone (900MHz and 1900MHz), but when I moved to Maine, I found the local GSM network here used another frequency, so I had to get a different phone. I ended up getting a Treo 600, which supports all 4 GSM frequencies: 850MHz, 900MHz, 1800MHz and 1900MHz.
Of course, now I wish I had the extra features that are on the Treo 650... mainly Bluetooth, a removable battery, and MP3 playing.
The one thing that I wish they made for the Treo phones that I haven't seen yet is a good car system. I have a Nokia 5190 phone and installed a complete system in my truck - snap the phone in the cradle and it locks in, connects to a mic, speaker, handset, power and antenna in the car. It can even mute the radio when the phoen rings, and it auto-answers in the car so you don't have to touch it at all. Nice! Wish all phones had a similar system. Alas, I can't use that phone here in Maine - wrong frequency!!!!! :-(