Here are video channels with telecoms related videos:
3G4G5G: Covering many different telecoms concepts including Spectrum, IoT, Signalling, History and 5G.
Mpirical: Short clips from a training company covering mobile and wireless technologies including 5G, 4G, VoLTE, WiFi and much more.
Apis Training: Long technology webinars on this channel along with their own training promotions.
TelecomTutorial info: Covering topics like NFV, SDN, IMS, VoLTE, etc.
Peter C: This channel looks at mobile radio networks, mainly in UK.
Communication Systems, Linköping University, LI: This channel contains lots of useful information on Massive MIMO research.
Moniem Education: This channel contains topics 5G topics.
Alan Talks Tech: This channel provides information on many different telecommunication technologies but not updated regularly.
Irfan Ali: This channel contains lots of useful 4G (LTE) related topics but has not been updated for a while.
Kumbesan Sandrasegaran: This channel covers many different topics on 2G (GSM), 3G (UMTS), History, Fundamentals of wireless, 4G (LTE), etc but the channel has not been updated for a while.