Oi users enjoyed better mobile network experience post-migration

The sale of Oi’s mobile unit to its mobile competitors — Claro, TIM and Vivo — was one of the most significant events in the Brazilian mobile market in 2022. The transaction was finalized in April 2022, for BRL 15.9 billion ($3.4 billion) and the sale included the transfer of Oi’s assets to the respective buyers — infrastructure and spectrum — along with migrating Oi’s customers to the new networks. TIM has gained 14.5 million of Oi’s customers while Claro and Vivo — 11.6 million and 10.5 million, respectively — with the subscribers being assigned to new networks based on a geographical split. Oi subscribers were transferred under a roaming-like model in the first stage, with the full integration with the host networks planned for completion early in 2023, according to information obtained through the Technical Cooperation Agreement between OpenSignal and Anatel.

Opensignal has analyzed the experience of our Oi users after they migrated to their new networks, still under a roaming-like model. We observed significant increases across speed, availability and experiential metrics for this group of users. Opensignal also looked at how the transfer of Oi subscribers impacted the experience of our users that subscribe to the other operators. While TIM and Vivo’s networks seemed unaffected, Claro users observed a slight dip in their average 4G Download Speed and LTE RSRQ values, indicating increased congestion.

In the last Opensignal Brazil Mobile Network Experience report with Oi results included, our users on this network experienced average download and upload speeds substantially lagging behind their peers on other networks. However, when comparing two data collection periods — before the sale was finalized in mid-April (90 days starting on Feb 1, 2022) and six months later (90 days starting on Aug 1, 2022) with the migration already in progress — we observed impressive boosts of around 50% of average download and upload speeds. Our Oi users enjoyed 4.6 Mbps faster average download speeds and 1.9 Mbps faster average upload speeds after being migrated to their new networks.

Network availability is also critical to understanding users’ mobile network experience. Limited availability restricts access to better throughput — or at times, to a mobile signal at all. Similar to speed metrics, our Oi users observed significant improvements across all observed availability metrics. Time spent with no mobile signal reduced for them by a sixth in the analyzed data collection periods, from 4.1% to 3.4%. During this period, Oi users also spent substantially more time connected to 4G and 5G services, seeing an impressive boost of 13.8 percentage points, to nearly 70% in August-October 2022. This means a stunning increase of nearly a quarter of time spent on 4G and 5G services, compared to the period of February-April 2022.

Our Oi users also saw substantial improvements across the experiential metric — Video Experience, Games Experience, and Voice App Experience, with increases of 7.5, 8.6, and 5.6 points, respectively. This means our Oi users had a better experience when streaming videos, playing multiplayer mobile games, or using over-the-top voice services on their smartphones after the migration.

While Download Speed Experience increased by 50.4% for Oi migrated users at a national level, we observed even more spectacular boosts in some of Brazil’s cities. Oi users in São José dos Campos, Ribeirão Preto and Cuiabá saw the highest improvements in relative terms across all Brazilian cities six months after the Oi’s mobile unit sale was finalized, with their download speeds around 2.5 times faster. This brought their average download speeds from single to double digits, from around 5-6 Mbps seen in February-April 2022 to 13-14.8 Mbps in August-October 2022 — demonstrating the impact of migration for Oi users in smaller Brazilian cities.

Looking at the three most populous cities in Brazil — Brasília, Rio de Janeiro and São Paulo, the registered average download speeds increases were less substantial, compared to some smaller cities. Our Oi users in São Paulo enjoyed the highest increase in Download Speed Experience of 7 Mbps — two-thirds of the speed they saw before the migration (10.8 Mbps). Average overall download speed increased for Oi users in Brasília by a third (4.5 Mbps) post-migration, while those in Rio de Janeiro experienced a more modest rise of 1 Mbps, with Download Speed Experience clocking in at 18.6 Mbps.

Macapá, Nova Iguaçu and Campinas are three cities in which we observed the highest increases in time our users had a 4G or 5G connection — with 4G/5G Availability scores more or less doubling during the migration process. Macapá saw the highest increase in the country across all Brazilian cities, of 42.4 percentage points - meaning, our Oi users went up from spending more than a third of the time connected to 4G or 5G services up to nearly 80%.

The improvements varied for the three of Brazil’s largest cities — Brasília, Rio de Janeiro and São Paulo. While Brasília observed a more humble growth of 7.3 percentage points, around a tenth of the time that our Oi users previously spent connected to 4G or better services — their peers in Rio de Janeiro and São Paulo enjoyed much bigger improvements, of 18.8 and 23.3 percentage points, respectively. 

Having to absorb between 10.5 and 14.5 million migrated subscribers per network poses a tremendous challenge for the remaining three mobile networks in Brazil and can lead to network congestion. Opensignal analyzed our Claro, TIM and Vivo users’ average 4G download speeds in both data collection periods. While our TIM and Vivo users observed slightly higher results six months after the Oi sale was completed, with increases of 0.5 and 1.4 Mbps respectively — Claro’s 4G Download Speed score was 8.6% slower and dropped by 2.4 Mbps. 

This drop is likely due to congestion on Claro’s network, driven by new subscribers migrated from Oi. Further support for this hypothesis comes from changes in the operators’ LTE Reference Signal Received Quality (RSRQ) values. RSRQ measures signal quality and lower RSRQ values can be indicative of more congested networks. While RSRQ scores dropped by 0.08 and 0.04 dB for our TIM and Vivo users respectively, Claro users saw a much steeper decline of 0.42 dB, with the gap in quality of signal widening between Claro and its competitors since Feb-April 2022.

5G connectivity will offset network congestion coming from migrated subscribers

Opensignal’s data demonstrates significant improvements in mobile network experience for Oi users — both in terms of faster speeds and enhanced signal availability — after they were migrated to Claro, TIM and Vivo. Absorbing millions of new subscribers creates a major challenge for these three operators to maintain the levels of network quality they had so far. Additional spectrum transferred from Oi will help to offset the network traffic coming from the influx of migrated subscribers — however, recent rapid improvements in Brazil’s 5G network experience driven by deployments in the 3.5 GHz band will also contribute. Opensignal will continue monitoring how the migration of Oi users improves their mobile experience and how it affects the quality of their new host networks.