According to the Telecommunication Standardization Sector (ITU-T), what is a next generation network (NGN)?

A next generation network (NGN) is defined as a packet-based network that can provide a range of telecommunication services, including traditional voice, data, and multimedia services. The key feature of NGNs is their ability to use packet-switching technology, which divides data into packets that can be transmitted across the network independently and reassembled at their destination. This approach enhances efficiency and flexibility compared to traditional circuit-switched networks, which establish a dedicated connection for each call or data session.

NGNs support various service types (e.g., voice, video, data) over a single infrastructure, utilizing IP (Internet Protocol) as the fundamental technology. This allows for seamless integration and convergence of different services, improving resource utilization and simplifying network management. The emphasis on a packet-based architecture is central to the definition of NGNs, as it promotes modern communication capabilities that are essential in today's digital environment.

The other options refer to specific types of networks that do not align with the broader concept of next generation networks. Circuit-switched networks, for instance, are less efficient for modern services that require high-speed data transmission and flexible service delivery. Fixed and wireless networks represent particular access technologies rather than the overarching framework used in NGNs, which emphasize packet-based technology and service