The links provided here are to the meeting calendars of SDO committees that are active in the development of 5G standards and have active federal participation.
List of SDOs/Groups and Calendars of Meetings:
3GPP - Info retrieved here: https://portal.3gpp.org/#/
IEEE 802 - Information retrieved from http://www.ieee802.org/meeting/index.html
IEEE 802.1 Interim Meeting Information Page – IEEE 802.1 holds meetings during the IEEE 802 Plenary Sessions in March, July and November each year, and usually during IEEE 802.1 Interim Sessions in January, May and September. Some projects also hold teleconferences which are authorized in advance and announced on the IEEE 802.1 mailing list.
IEEE 802.11 Interim/Plenary Sessions Information Page
IEEE 802.15 Interim Meeting Information Page
IEEE 802.24 Interim/Plenary Meeting Information Page - 802.24 meets at IEEE 802 Plenary Sessions and Wireless Interim sessions. Refer to the meeting plans for 802.11 and 802.15 for meeting dates and logistics.
IETF - https://www.ietf.org/how/meetings/upcoming/, also https://datatracker.ietf.org/meeting/upcoming
ITU - https://www.itu.int/en/events/Pages/Calendar-Events.aspx?sector=ITU-T