In the last blog I did a quick update on the different levels of 3G your smartphone or rugged PDA or even tabvlet can have so today I thought i’d help extend that knowledge into underdstanding exactly what the “phone and data” section of the spec sheet actually means!
So as Judge Jules always used to say, “We continue!”
If we look at a typical phone and data section of a rugged pda we’ll something like this:
Type of 3G
This explains the level of data connectivity the device has and this is what I explained in the last blog. So you’ll often see 4G at the top, followed by all the 3G prototcols, in this case HSPA+, HSDPA, UMTS and then the 2G protocols such as Edge and GORS and lastly the modem base protocol, GSM. The rule of thumb here is that all data connection are backward compatible so if the device has 4G, it’ll work at any speed downwards. You’ll see in trhis case the device in question can operate on HSPA+ and below, which is 3.9G and below.
Phone networks compatibility
There are in fact 2 completely different phone networks in the world and where there are multiple network operators working on the same network type, they have to work on specific frequencies. Here in Europe we have the luxury of only ever connecting to one and this is known as the GSM network. Where you have multiple operators, for example EE, O2, Vodafone and 3, these all operate on their own different frequencies.
To be honest, I can’t even think of any phone that won;t work on any frequency any more so if you buy a Rugged PDA in the UK that works on the GSM network it can be connected to any operator. Many manufacturers omit this off the spec sheet now to reflect this but if you do see things like 900MHz or 2100MHz then this is what they mean!
In other continents the CDMA network type is used and in some, like Africa and the USA both are present. This is what the second section on the spec sheet is talking about so you’ll see lots of Now it’s often not cut and dry but generally if you see terms like GSM then the phone can be used on GSM networks and like-wise terms like CDMA/EVDO then it works on CDMA based networks.
To give you a real world example in the USA. AT&T is a GSM based network and if you were from the UK years ago then your phone would probably have connected to this network. Verizon is a CDMA based network and this probably explains all the bother about the iPhone only originally working on AT&T. The reason was it only had a GSM chip in it.
Now-a-days, especially if the device has a 4G capable chip, this has all become a little bit pointless, however with Rugged devices having longer technology refresh cycles, there are still some that you have to be careful of and choose the right chip for. Always ask if in doubt!