Commercial 5G networks may not launch until 2020, but subscriber growth on the new networks will likely be fast. According to Cisco’s annual global mobile data study, 5G connections will top 25 million by 2021 and will generate 30 Gigabytes of data per month, nearly 5 times the amount of data generated by 4G connections in 2016.

The study also says that 5G will account for about 1.5 percent of mobile data traffic in 2021. 2G data, meanwhile, will drop to less than 0.6 percent of mobile data traffic as wireless operators globally migrate traffic to higher speed networks.

Look for the popularity of mobile video to continue to escalate. According to the study, mobile video will increase 8.7-fold from 2016 to 2021 and will make up 78 percent of all mobile network traffic by 2021.

Mobile data traffic overall will increase seven-fold in the next five years from 87 exabytes in 2016 to 587 exabytes in 2021, according to the study.

Cisco’s study, which is always highly cited industry-wide, also said that machine-to-machine connections are the fastest growing type of IoT connections and will account for 29 percent of connections, or 3.3 billion, up from 5 percent, or 780 million in 2016.

Interestingly, the Cisco study says that by 2021, 46 percent of M2M connections will be over the 4G cellular network, compared to 31 percent that will be on a low-power wide area (LoRa) M2M network. In 2016 LoRa carried about 7 percent of M2M traffic compared to 4G, which carried about 23 percent of M2M traffic.