The term “next generation access (N

The term “next generation access (NGA)” is commonly used to describe the requirement of fibre coming closer to the end-user, or providing the direct connection i.e. the connection from customer to network node. The traditional copper or cable wire is largely or entirely replaced with fibre-optic technology. The new wireless technologies can also be regarded as NGA technologies.
An NGN is divided into two distinct layers: the service layer and the transport layer. Service-related functions are independent of underlying transport-related technologies and there is unfettered access for users to networks and competing service providers. Thus, the users of the NGN are able to freely choose among services from different service providers. The NGN concept is focused on the provision of services, and is independent of users’ access technologies. The cost elements will depend on whether the cost is caused by subscribers or traffic. Unlike the traditional models where network capacities are measured mainly per subscriber or per voice call or minute, in an NGN model, there are four relevant measures of capacity:
1) per subscriber, applying mainly in the access network, though billing systems may have a per subscriber element;
2) per megabit of traffic;
3) per packet of traffic;
4) per session.