The number of mobile subscriptions in Africa is expected to pass 1 billion in the fourth quarter of 2016, reaching 1.02 billion by year-end.

This is according to global data, market research and advisory firm Ovum, which also forecasts that the total number of mobile subscriptions on the continent will rise to 1.33 billion by the end of 2021.

The average rate of mobile penetration in Africa was 79% at the end of June, but in spite of these landmarks, growth in new mobile subscriptions is slowing.

Ovum also reports mobile voice revenue on the continent is set to decline over the five years to 2021, with data connections, as well as data and digital service revenue, driving the next phase of growth in Africa's telecoms market.

"As Africa nears the landmark of 1 billion mobile subscriptions, it is clear that the next phase of growth will be in broadband connections and in revenue from data access as well as from new 'digital services' such as digital media and mobile financial services," said Matthew Reed, practice leader for the Middle East and Africa at Ovum.

"However, Africa remains less advanced than most other world regions in its broadband development, and there is both an opportunity and a need to further improve connectivity on the continent, and to take advantage of the benefits that connectivity can bring."

That being said, Ovum still believes the take-up of mobile broadband will rise strongly as African mobile operators continue to roll out 3G and 4G/LTE networks, while smartphones are also becoming increasingly affordable.

Of the 1 billion mobile broadband connections Ovum predicts there will be in Africa by 2021, 157.4 million of these will be via 4G/LTE. The number of smartphone connections on the continent will reach 929.9 million by the end of the same year, with non-SMS mobile data revenue in Africa rising to US$27.56 billion from US$6.40 billion in 2015.

The number of fixed broadband connections will also increase significantly, albeit from a very low base, hitting 19.97 million at the end of 2021 compared with 13.78 million at the end of 2016. Fibre and fixed LTE connections will see growth, with DSL however remaining the dominant fixed broadband technology.

Despite this projected growth, Africa still ranks second lowest among world regions in its broadband development, according to Ovum's Broadband Development Index (BDI). The BDI measures countries and regions based on their adoption of high-speed broadband. Africa's score of 232 out of 1,000 at the end of 2015 is ahead of only Central and Southern Asia.