131–140 of 141 posts
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Really, they give you a new sim on upgrade? I can understand this if you are upgrading TO an iPhone since you need a micro SIM, but rather pointless otherwise. I think I've had the same SIM card for about 6-7 years now!
Older sims dont have 3G capabilities either. (Not sure why)
I'm afraid if we kill SIM cards, the opposite will happen: your phone will be locked to one network, and switching networks means switching hardware (beyond just the sim). I really like that while traveling I can just buy a local sim, put it in my own phone, and use it. That would only work in these wireframes if all operators would agree to support this. Which I think they won't.
This assumes you have a phone that isn't already SIM-locked, like most of them are when purchased from carriers.
The SIM is an integral part of the GSM standard and provides a huge range of benefits. The point of their existence is to establish the identity of a subscriber independently of a handset , which has a lot of interesting, useful and important side-effects. A very large proportion of GSM subscribers use dual-sim handsets, to take advantage of the cheapest available tariffs. This is the norm in price-sensitive markets…
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Older sims dont have 3G capabilities either. (Not sure why)
Mine is defo new enough that it supports that! Anyone know if you need a new sim card to support 4G services?
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This assumes you have a phone that isn't already SIM-locked, like most of them are when purchased from carriers.
I will definitely be shopping more carefully the next time I purchase a phone. I have an AT&T iphone 4. It works well, I have good coverage, and it can be used internationally, but AT&T will never unlock a phone, even after your contract is up, or if you are traveling overseas. I was in Europe for a week, and as soon as the phone connects, I get a text from AT&T saying that the data rate is $19.97/MB! Data was off, b…
The SIM is an integral part of the GSM standard and provides a huge range of benefits. The point of their existence is to establish the identity of a subscriber independently of a handset , which has a lot of interesting, useful and important side-effects. A very large proportion of GSM subscribers use dual-sim handsets, to take advantage of the cheapest available tariffs. This is the norm in price-sensitive markets…
I've found that the opposite is true when traveling - every new country I go to requires a different (local prepaid) sim card. My iPhone 4S stays the same, but I end up with a new sim card and phone number while I'm in the country, and then end up throwing out the sim card once I leave.
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That's been the case for ages because Verizon is a CDMA network, not GSM -- GSM takes SIM cards, while CDMA does not. Different tech. This is likely to shift as V rolls out LTE, which DOES take SIM cards. So we're actually likely to see more intercompatibility as things progress. Except, of course, that everything's still likely to be carrier-locked.
Is there actually any benefit to CDMA?
GSM used TDMA which sliced a frequency into time slots. The time slots are allocated to the phones whether there is talking or not. This also leads to a fixed number of connections per frequency, and adjacent towers can't use the same frequency. It is also not forwards compatible since the phones expect certain behaviour from other phones in terms of using the time slots. That is why GSM carriers had to go out and get new frequencies when they added 2G data.
CDMA just has all phones broadcast at once. The phones merely see others as noise. When there isn't anything to transmit (voice calls have a lot of silence) then not much is transmitted. The tower will direct power levels to phones to keep the noise as low as possible. The net effect is that there isn't a fixed number of connections per tower/frequency, adjacent towers can use the same frequencies and it is forwards compatible - other phones can use newer versions and it won't affect current phones. CDMA is a lot harder engineering.
Here are a bunch of articles describing it in more detail from someone who worked on it.
http://denbeste.nu/cd_log_entries/2002/10/GSM3G.shtml (politics, tech, how CDMA happened) http://denbeste.nu/cdmafaq/cdmatdma.shtml (tdma versus cdma) http://denbeste.nu/cd_log_entries/2002/04/Howspreadingactual... (what actually gets transmitted)
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And complete anonymity. Most people don't care about this, but some of us do, sometimes. You buy a pay as you go sim card for £10, pay with cash, and toss it a week or month later.
Can you still do this? I've tried in a few countries but had to register online with all my personal details before the card got activated.
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Can you still do this? I've tried in a few countries but had to register online with all my personal details before the card got activated.
You can in the UK.
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I will definitely be shopping more carefully the next time I purchase a phone. I have an AT&T iphone 4. It works well, I have good coverage, and it can be used internationally, but AT&T will never unlock a phone, even after your contract is up, or if you are traveling overseas. I was in Europe for a week, and as soon as the phone connects, I get a text from AT&T saying that the data rate is $19.97/MB! Data was off, b…
That's not strictly true -- they just won't unlock an iPhone. http://www.att.com/esupport/article.jsp?sid=55002&cv=820...