Final answer:
ISDN allows voice and television services but not mobile phones or internet access.
Step-by-step explanation:
Integrated Services Digital Network (ISDN) is a digital transmission that allows voice and television services. It is primarily used for voice communication and video transmission. ISDN is not specifically designed for mobile phones or internet access.
The following services are supported by SDN:
1. Voice: High-quality audio transmission is made possible by ISDN's digital voice call transmission capability. Compared to conventional analog telephone lines, it provides better voice clarity.
2. Internet: A digital connection to the internet can be made with ISDN. It offers a dedicated connection that is dependable, which can be crucial for applications that need a consistent and stable internet connection.
3. Cell phones: Mobile phone services can be supported by ISDN. It can be used to transfer data and make mobile voice calls.