Load shedding crushes mobile internet in South Africa
Offloading has a direct impact on the mobile network infrastructure and as a result, mobile internet speeds tend to suffer.
A MyBroadband analysis showed that Vodacom and Telkom customers saw the biggest drops in network performance during periods of load shedding.
We compared average mobile data speeds during a period of load shedding and unconstrained power.
The data confirmed that mobile networks struggle to maintain performance during continuous power outages.
We used tests performed using the MyBroadband Speedtest app to compare two one-week periods.
We used MyBroadband Speedtest data from the week of September 7-14, 2022, when South Africa experienced consistent power outages.
We chose the period from August 19 to 26, 2022 – during which there were no significant power outages – as a control.
The first thing that immediately stands out is that users performed significantly less testing during load shedding periods.
The most notable case is that of Telkom, where users performed 62% more tests than usual during load shedding.
While this may be due to users not having internet access during load shedding periods, this discrepancy may also be due to users with higher data caps not having electricity for their home routers.
Rain and MTN did not see a substantial change in the number of tests performed. The rain has indeed recorded a slight increase in tests during the load shedding period.
Across all five networks, subscribers performed 79% more tests in load shedding than in unrestricted power.
We also looked at the average speeds achieved during these times to see how the experience changes for users who can still connect.
Cell C and Rain performed exceptionally well, with speeds improving across the board during shedding.
This could be due to the fact that a significant part of its customer base does not have access during these periods, which reduces congestion on its network.
Rain also improved his average download speed and latency, but his average download speed decreased slightly.
MTN remained surprisingly constant throughout the load shedding, with its average download speed at less than 95% of typical values and its upload speed dropping to 90%. Latency improved slightly during offload.
Vodacom and Telkom experienced the worst degradation in download speeds and latency during rotational power outages.
Their average download speeds dropped to 84% of the period without offloading, while latency was about 13% lower than normal.
The combined numbers clearly show that although some carriers manage to keep their networks together during extended power outages, many users cannot access the internet during these times, and those who do may generally have a worse-than-usual experience.
Load shedding between September 7 and 14
For perspective, Eskom implemented phase 2 load shedding all day from Wednesday, September 7, and extended the timeline for implementation rotating blackouts all night Thursday of the same week.
The electric utility attributed the power outages to various generating unit outages and the need to replenish its emergency reserves.
On Friday September 9, Eskom announced that it increase shedding in step 3operating all weekend until 05:00 on Monday 12 September.
However, Stage 3 never arrived until Monday, with the electric utility move rotating blackouts to step 4 Saturday, September 10.
Level 4 load shedding was in effect for the remainder of the test period used for our comparison.
Notably, the rotating blackouts have since worsened, reach stage 5 Saturday, September 17, then Step 6 the next day. Load shedding is set to return to step 5 to Tuesday midnight.
The results of our load shedding network performance comparison are summarized in the table below.
|Performance of the load shedding network|
|Network||To download||To download||Latency||Trials|