The maximum possible speeds a phone or modem can achieve on it are one of these:
1. approximately 110Mbps download and 35Mbps upload if you have a cheap phone or a "150Mbps" modem; or
2. approximately 110Mbps or 150Mbps download and 35Mbps or 55Mbps upload if you have an expensive phone.
Because applications that do downloading tend to display download speeds in kilobytes per second instead of kilobits per second, 150Mbps is 18.75MB/s or 18750KB/s.
For each one of these steps, the speed is improved because 4G is allowed to communicate in ways that are even more subtle.
It is impossible to detect subtle communication if the signal is bad, so the performance of the 75Mbps phone or modem will automatically match the 150Mbps phone or modem if no other factors affect it.
A modem or phone that supports a higher maximum upload speed may have "UL 64QAM" in its specifications.
A modem or phone that supports a higher maximum download speed may have "256QAM" in its specifications.
If a modem or phone has a "download speed" of "300Mbps", that does not imply UL 64QAM nor does it imply DL 256QAM. "300Mbps" normally only adds a feature that isn't relevant at the moment (ability to aggregate up to 40MHz). Expect a download speed of up to 110Mbps from that "300Mbps" phone or modem. Category 6 may be shown instead of 300Mbps. 450Mbps phones and modems have similar implications.
If a modem or phone has an "upload speed" of "75Mbps", that's UL 64QAM. If it has an "upload speed" of "50Mbps", that's not it.
If a phone or modem supports DL 256QAM or UL 64QAM, it is not guaranteed that it will support these on Vodafone Ghana.
A tower may have either, both, or none of these. Fortunately, Vodafone deployed these in many parts of the country.
What makes the signal good or bad? This image provides an example of how speeds may vary while connected to a sector aimed north.
Aside from "what makes the signal good or bad", congestion or a slow backhaul can be reasons why there's a slow connection in some areas. The image at the beginning of the page provides an example of how a part of a backhaul may be set up, in addition to an example of a connection to a mobile phone.
ITU-R's IMT-Advanced (4G) requires 1 Gbit/s for low mobility. LTE achieved a download speed of approximately 1.2Gbit/s (approximately 1200Mbit/s) in Release 10 (LTE-Advanced) by using 8 discrete antennas and an aggregated bandwidth of 40MHz.
Vodafone uses 791MHz - 806MHz for downlink and 832MHz - 847MHz for uplink. So instead of 40MHz, there's a total bandwidth of 15MHz to download with (15 between 791MHz and 806MHz). 798.5MHz is in the middle.
1200 * (15 / 40) = 450. So it would be approximately 450Mbps if it were to be with 8 discrete antennas.
Very few phones and modems have 4 discrete antennas that will work with 791MHz - 806MHz. Buy the most expensive phone possible, and it's almost guaranteed that it will only have 2 inside. If a phone or modem has 4, only 2 antennas can act individually because Vodafone towers use 2 discrete antennas.
8/4=2 discrete antennas. 450/4 leads to a result close to the 110Mbps approximate used above.
Today, 4G most commonly means LTE, regardless of its maximum possible speed.
Phones that support "4x4 MIMO" are almost guaranteed to use only 2x2 MIMO (2 antennas acting individually) with Band 20. Some other bands work with 4x4.
Where does Vodafone have a gigabit now?
It is possible for it to be anywhere other than the air interface between a phone and a cell tower.
This configuration applies, at least for the following conditions: Prepaid, a bundle worth 3.25 Ghana Cedis, and the "browse" or "internet" APN requested.
On some mobile network operators, it is set up as a suggestion instead of a limit.
...
Quality Of Service - Negotiated QoS
...
Maximum bitrate for uplink: 8640 kbps (254)
Maximum bitrate for downlink: 8640 kbps (254)
...
Guaranteed bitrate for uplink: 0 kbps (255)
Guaranteed bitrate for downlink: 0 kbps (255)
...
Maximum bitrate for downlink (extended): 160 Mbps (202)
Guaranteed bitrate for downlink (extended): Use the value indicated by the Guaranteed bit rate for downlink (0)
Maximum bitrate for uplink (extended): 256 Mbps (250)
Guaranteed bitrate for uplink (extended): Use the value indicated by the Guaranteed bit rate for uplink (0)
...
APN aggregate maximum bit rate
...
APN-AMBR for downlink: 8640 kbps
APN-AMBR for uplink: 8640 kbps
APN-AMBR for downlink (extended): 160 Mbps
APN-AMBR for uplink (extended): 24 Mbps
Use the value indicated by the APN-AMBR for downlink and APN-AMBR for downlink (extended)
Total APN-AMBR for downlink: 160.000 Mbps
APN-AMBR for uplink (extended-2): 512 Mbps
Total APN-AMBR for uplink: 536.000 Mbps
...
Why only 15MHz?
Sometimes more licenses can be obtained from the NCA, but it is expensive.
Band 20 is currently split in half between Vodafone and MTN.
What if the whole of Vodafone's 2G and 3G were refarmed into 4G instead, completely ignoring compatibility?
- 3G: 15MHz of Band 1
- 2G: 9.8MHz of Band 3
- 2G/3G: 8MHz of Band 8
- 4G: 15MHz of Band 20
Band 1. Some modems and some phones support 4 discrete antennas on it. So, that's +300Mbps.
Band 3. Some modems and some phones support 4 discrete antennas on it. In 10MHz LTE, only 9MHz is used and the remaining 0.5MHz on each side is its guard band. If 0.1MHz of its guard band on each side is allowed to overlap with other networks, +200Mbps.
Band 8. Let's split it into 5 + 3. 2 discrete antennas. +50Mbps +30Mbps.
Band 20. +150Mbps.
Add all of these approximate speeds to get 300+200+50+30+150=730. But it isn't as simple as being able to use all of these at the same time.
If a modem or phone supports CA_1A-3A-20A, that's 650Mbps.
If Vodafone SIMs were to roam on MTN's 4G, would it then reach a gigabit?
No, phones and modems on MTN's 4G cannot reach a gigabit.
An important correction was made to this page on April 2, 2022. Upload speeds are now for 15MHz (what Vodafone has), instead of 20MHz. 2. December 16 2022, removed the 100Mbps modem.