This brings to 111 the number of commercial 5G deals or contracts with operators that Ericsson has globally, including 65 live networks.
The 5 core will be built on Proximus' cloud infrastructure, Ericsson said in a statement, adding that the cloud-native solution was based on its dual 5G Core.
The same technology will be used for the renewal of the 4G network. Proximus has about 45% of the Belgian market.
"Proximus is committed to building the best gigabit network for Belgium, and the renewal of our mobile network equipment is a key element in this strategy for the coming years.
"Together with Ericsson, we will work hard to build a best-in-class, energy-efficient, and future-proof mobile network for the benefit of the entire country.”
For both companies, this will be the first large scale collaboration in Belgium.
Ericsson's president for Europe and Latin America, Arun Bansal, said: “The core is a crucial part of any network. With decades of experience and live 5G networks all over the world, Proximus has chosen Ericsson to deliver reliable, sustainable and secure connectivity.
"Our cloud-native solutions mean an efficient transition to a future-proof network, and with our leading 5G portfolio, we are ready to support the market leaders in Belgium to deliver 5G.
"5G will be critical national infrastructure in realising Belgium’s digital future, boosting investment in the country and driving the digital economy.”