India’s telecom service providers are still struggling to provide consistent 4G network coverage across the country.

The only exception to this is Reliance Jio, the mobile operator led by India’s richest man, Mukesh Ambani. This network is available in 98.8% of locations across the country that were tested for a recent study by the internet analysis website Speedtest. The study was conducted between July and December of 2018, using data from over 250 million samples on almost 600,000 devices.

Jio, which launched 4G services in September 2016, well after Bharti Airtel (2012) and Vodafone (2015), has been posing a stiff challenge for incumbents. Some experts predict that Jio will have the largest subscriber base out of all mobile operators in India by the end of the 2019-2020 financial year.

While 4G availability is limited, the general availability of cellular service in India is much better. Here, too, Jio is the winner.

Advertisement

“Except for a few red spots at the edges of Uttarakhand, Rajasthan, Sikkim, and the Andaman Islands, Jio’s 4G availability map is nearly identical to their general availability map,” Speedtest said.

Who wins the race?

But coverage does not equal speed. The study showed that while Jio may rule the roost in terms of cellular and 4G availability, Airtel was the fastest, both in cellular service as well as 4G.

Speedtest measured these metrics using speed score, a “combined measure of download and upload speed that incorporates several tiers of performance.”

Speedtest also studied differences in general and 4G availability across India’s 15 largest cities, as “country-wide averages can hide a lot of information.” When it came to general cellular availability, Airtel showed availability at or over 99% in all of the cities, while Jio had less than 99% coverage in just one city: Jaipur.

Advertisement

Vodafone and Idea performed well, too, but both had distinct weaker spots. Vodafone showed 97.9% in Kolkata, and Idea had 96.6% coverage in Indore. The two service providers merged last August, but retain separate brands.

“While these scores are all good, consistent mobile service is important to quality of life,” Speedtest said. “If a consumer is living in one of the small sections of these cities that are not well served by their mobile operator it could mean they don’t have access to internet at home, school or where they do business.”

When it came to 4G availability, scores were much more varied – except for Jio, which showed near-total coverage in almost all cities. Airtel’s coverage was in the low 90s in several cities.

Advertisement

Vodafone and Idea performed much worse in select cities. The former’s coverage was 75.9% in Hyderabad and 77.5% in Visakhapatnam, and the latter’s was 68.4% in Kolkata and an abysmal 38.8% in Delhi.

This article first appeared on Quartz.