QUOTE(wild_card_my @ Jan 17 2019, 01:10 PM)
Ah. I feel poor for using poorman's phone.
>
"None of Malaysian carrier had enough allocation on a single band so this is out of the question." Sorry I don't understand what you meant by "out of question". Do you mean that in general, the Malaysian carriers dont have enough allocation in a single band, in that
intra band is out of the question for them? So the only way to go around this is to use
inter-band which they are capable of doing/servicing; but doing Inter-band CA would also depend on the customers' phone - of which if my Xiaomi MiA2 does not support inter-band, then I would be out of luck?
If I am right, a follow up: Why do I need a CA? Why not I just use the small spectrum allocated/assigned (?) to my phone at any given moment? Is it to increase my bandwidth?
Another follow up: How do I know which phone implement both inter/intra-band CA? Is it printed on the box? What about on GSM Arena specs list...?
For the first part, you understood it correctly.
As for why do you need CA? CA increases the download speed by bonding two spectrum together to form a big fat pipe. You are totally fine for using typical 4G phone which doesn't comes with any CA but to better take advantage of the network especially if you're located in areas with high network utilization (or network congestion), the differences is noticeable.
How do you know the phone comes with full support for CA? You don't. You learnt from experience. Most customers are not a tech enthusiast, they (manufacturer) can't be bothered about this fact and they just omitted it. I got my first hand experience when I bought the Redmi Note 3 Pro which advertised as 4G+ capable but I was surprised I didn't able to take advantage of it in Malaysia. I then did some research and concluded that my phone only had intra-band CA support. Some Indian owners of this phone came out with a detailed investigation and come out with proof that re-affirms my findings. After that, it spread across all the Xiaomi devices which advertised as 4G+ but only had intra-band CA support. After this wider discovery, Xiaomi had never advertised their phone with 4G+ support although they do support intra-band CA.
People will also question since most Chinese owner of this phone are tech geek, why did they not complain about this matter. The answer is intra-band CA was very widely used in China and they are happy about it because it works as they expected (4G+ phone are indeed connecting to a 4G+ network).
If you're interested to learn a little bit more, take your time to read below information:
Intra-band CA is commonly used on TDD LTE frequency bands but quite rare in FDD LTE frequency bands. Inter-band CA is almost every time on a FDD LTE but quite common on TDD LTE bands.
https://en.wikipedia.org/wiki/LTE_frequency_bands (this gives you an idea which band are TDD and which are FDD)
https://www.cablefree.net/wirelesstechnology/fdd-vs-tdd/ (Differences between TDD and FDD)
and so this is why you could see devices that only comes with intra-band CA are able to connect to the 4G+ network on Unifi Mobile(Side note: plus Yes 4G if they implement some time soon) but not on any other carrier in Malaysia.