South African mobile data speed problem

Mobile Internet upload speeds have not kept pace with the significant surge in mobile download speed in South Africa over the past few years.

A MyBroadband reader recently contacted us and complained about “terrible” upload speeds compared to download speeds on their mobile connection.

“They are generally only about 10% of the download speed,” the reader said. “Is there a simple explanation for this?”

South Africa’s mobile upload speeds have always been slower than downloads.

Nevertheless, MyBroadband decided to investigate whether there were any noteworthy trends in the two metrics that may have caused the reader to take notice of this difference.

Analysing MyBroadband Insights’ Mobile Network Quality reports from the past five years showed that average download speeds have increased far more than upload speeds.

These reports are based on hundreds of thousands of mobile speed tests performed in South Africa on MyBroadband’s Speed Test app.

In the latest report for the second quarter of 2024, the average mobile download speed in South Africa was 70.41Mbps, compared with 25.67Mbps from the same period five years ago. That works out to an increase of 174%.

Over the same period, the average mobile upload speed went from 9.61Mbps to 15.94Mbps, a much more modest increase of 66%.

Both metrics have improved tremendously thanks to substantial network investments by South Africa’s mobile operators.

However, perhaps the disparity is more noticeable because many more speed tests are showing triple-digit downloads and double-digit upload speeds.

One major reason for the growing gap could be the rapid expansion of mobile 5G services, which were first launched by South Africa’s two biggest mobile networks — Vodacom and MTN — in mid-2020.

While both 4G and 5G have faster download speeds than upload speeds, the difference is particularly pronounced with the newer technology in South Africa.

MyBroadband analysed the recent 4G and 5G speeds of South Africa’s top network vendor, Huawei, on the country’s three mobile networks that support both technologies. This led to an interesting discovery.

We found the 4G upload speeds on each network were significantly higher than 5G when expressed as a percentage of download rates.

The average 4G upload speed was 32.4% of the download speed, compared with with average 5G upload speed being 14.4% of the 5G download speed.

The other equipment vendors — Ericsson, Nokia, and ZTE — showed similar trends.

The table below summarises our findings with regard to the differences in 4G and 5G download and upload speeds on Huawei’s equipment.

Technical limits and network trends

While 5G has seemingly increased the difference, there are two simple reasons why mobile upload speeds have always been lower than downloads.

Telkom explained that handsets typically use lower uplink modulation schemes than base transceiver station (BTS) downlink.

“The second limitation is the handset’s transmit power compared to the BTS transmit power and limited power,” Telkom said.

In addition, Telkom said the performance of 4G/LTE uploads were better than 5G becausethe latter is operating on C-band spectrum.

“The C-band is a high-frequency spectrum that is prone to higher path losses as a limiting factor,” Telkom said.

“The situation would be different if 5G was transmitting on mid-band frequencies.”

However, it is not only the technical capability that creates the difference.

Mobile networks intentionally provision more bandwidth for downloads as this traffic tends to be far greater than upload traffic.

The rate at which a user can pull data from the Internet impacts their experience in video streaming, web browsing, and file downloads.

There has been a surge in popularity of certain applications that require higher upload speeds — like video calling, file sharing, and online multiplayer.

However, most users still have more demanding download requirements.