Jakarta’s blackout had a nationwide impact on 3 and Indosat’s networks

Opensignal observed an impact on our Indonesian users’ experience following the massive electrical blackout which began just before midday on Sunday, August 4, local time. However, the resulting effects on mobile service we measured were not limited to the areas where the power went out — Jakarta and West Java — but spread to the whole of Java, Sumatra, Kalimantan and Sulawesi.

All Indonesian operators suffered an impact in Jakarta and neighbouring regions, but 3 and Indosat were affected nationwide

Our users across all mobile networks were affected by the 12-hour long blackout in those areas. However, while users of Smartfren, Telkomsel and XL only suffered a mobile network outage in the areas where the power went out, the blackout had an almost nationwide knock-on effect on Indosat and 3’s users.

Our users in Jakarta, Banten and Jawa Barat experienced degraded 4G services for more than 10 hours across all five national mobile operators, suggesting that smartphone users had to wait for power to be restored in order to be able to connect to 4G networks again. Our Telkomsel and Indosat users had to wait the longest time to see their 4G Availability rise back to normal levels (up to 19 hours in Jawa Barat), while our 3 users generally saw a more widespread dip in 4G Availability, but had 4G service restored more quickly than Indosat.

According to Opensignal's analysis, Smartfren’s 4G network was the quickest to fully recover. Our Smartfren users saw their 4G Availability restored after 11 hours, and experienced the highest 4G Availability across all regions during the blackout.


During the blackout, our 3 and Indosat 4G users in Jakarta saw their 4G Availability drop to less than 20% 

In our latest Indonesia report we found that our 4G smartphone users in Jakarta could access 4G networks at least 87% of the time regardless of their operator. On August 4, once the power outage occurred, our users across all five mobile operators experienced a drop in 4G Availability. However, while our Indosat and 3 users saw their 4G Availability dramatically drop to under 20% in the early hours of the outage, our Smartfren, Telkomsel and XL users saw a more gradual and limited drop.

August 4 blackout affected 4G Availability on all networks in Jakarta

Our 3 users in Jakarta experienced the largest effect, with their 4G Availability dropping from an average 90.4% to 12.9% at 1 p.m., while our Indosat users suffered the most prolonged impact, as the operator took 14 hours to fully restore the network in the capital.

Opensignal users on Telkomsel and XL networks had a very similar experience with 4G Availability hitting their lowest around the 50% mark, four and five hours respectively after the blackout began. Our Smartfren users saw the smallest impact and were able to connect to 4G networks at least 73% of the time throughout the whole power outage, likely because Smartfren’s network is more focused on limited geographic areas than the other operators, making it potentially easier to recover.  

It’s no surprise to see such a big impact on the mobile network experience from such a large power outage. Most networks may have emergency backup power, but it’s likely only for parts of the network and will have limited time duration. Therefore, what’s most interesting to analyze is how quickly each operator restores normal service for their users, not just the scale of the initial impact.