The 4G cyclic prefix, modulation (waves being bent every 0.0000714 seconds to communicate), the actual maximum distance being 13.5, Discontinuous Transmission, there being a distance of 0.015MHz between different waves rather than 1 Mhz shown in the illustration; are not taken into account in the illustration for simplicity.
If it were to be given a maximum speed, it would be 112.5Mbps (downloads would show 14.0625 MBps which is divided by 8), 3 per tower, as shown below. It is not possible to use 2 at once.
The up to 150Mbps 4G exists (256QAM) but devices would have to explicitly support it on MTN, so there wouldn't be much of a benefit for it to be common. Such information is not available on the specs of mobile phones, though these may show "150Mbps" which refers to 20MHz of bandwidth instead, give it a try on Band 7.
On top of that, it could be up to 300Mbps by attempting to separate the signal of 4 (instead of 2) antennas on the phone and the tower, but the device would have to be large for this frequency.
Though it is very commonly supported on both ends, 112.5 Mbps is not to be expected. It implies a perfect signal and no 'hiccups' somewhere along the line to the website. If 112.5 were to be shared among 2 users it would be around 56.25, and so on. It is not 112.5 per user.
The cell tower may adapt towards low signal:
-Tower 'talks' quickly.
-Mobile: What did you say?
-Tower 'talks' quickly.
-No reply from the mobile phone.
-Tower 'talks' 2x slower.
-Mobile phone: OK.
The tower would spend 2x more time 'talking' to the mobile phone, leading to a speed of 112.5/2 = 56.25Mbps. If 2 mobile phones operating at half the speed were taking a speed test, it would be split between them: 56.25/2= 28.125Mbps. A mobile phone is expected to reply OK 90% of the time, else the 'talking speed' will be lowered.
While downloading, and the phone is advertised as up to 300Mbps (applies to most), and the phone displays 4G+ or LTE+, and the tower uses both bands on the same direction, it may be possible to download from both bands for a total of up to 262.5Mbps (112.5 + 150); an improvement from the previous 225Mbps!
Band 7's characteristics fits urban and fixed coverage (the signal from other radios aren't as likely to damage the signal as much, 5 more MHz, line of sight)
Band 20's characteristics fits rural/extended coverage (goes further).
It is not necessary that a 4G tower has both.
So, it's a 1.5x boost in the speed of rural/extended coverage (or 1.3x with 4G+).
This page is not provided by MTN Ghana.