Services
- Telex services
- Recording services for telephone messages and music
- Audiotex services
- Voice mail services
- Multimedia message services (MMS)/Multimedia instant messaging services
- Voice transmission via power lines (voice over power line)
- Radio communication services
- Telecommunications services, microwave
- Integrated services digital network (ISDN) services
- Trunked radio service providers
- Payphone card network operators
- Telephone services, satellite
- Universal mobile telecommunications system (UMTS) services
- International telephone calling services
- Paging services
- Telephone directory enquiry services
- Telephone network operators, analog
- Telephone network operators, digital
- Telephone network operators, fibre optics