Comment by wjholden
Cellular networks.
I specialize in computer networking in my day job. Most of what I do is Cisco routers, Cisco switches, and Cisco firewalls. I would be interested in learning more about cellular networks. I haven't put any effort into exploring this for myself. If there is a track similar to CCNA → CCNP → CCIE then it isn't well-known (well, not known to me).
Same background as me, however I moved into cellular/mobile - not really any official routes I know of in the industry, certainly not like a Cisco track.
Typical route is work at a Telco or IoT company as Network Eng or Developer and naturally pivot into telco learning on the job.
Vendors will run training courses when you buy their kit which helps a little, but it’s mostly self learning or on the job.