ork. The high capac- ity demanded by 5G translates into high bandwidth need on the access links, which in turn drives up the cost of those links. A single access link needs to supply at least the single user peak rate, which can be high with 5G. Wavelengths and WDM (wave- length division multiplexing) will be used more and more in the access to reduce the amount of fiber needed. With small cell deployments (mmWave 5G bands), many of the requirements are even more demanding. Access tier infrastructure will also be shared more and more for multiple usages, due to the cost and difficulty of supplying the access links. In the access tier, operability is of specific importance. Configuration and operation of the access tier has to be automated and as simple to operate as possible with trou- bleshooting capabilities. In the distribution tier, traffic flows from the access hub sites, and access links are collected. The architecture is scalable and resilient, and basically an arbitrary number of new access regions and sites can be added with connectivity services based on IP defined as needed between sites, for example, with IP MPLS VPN service (PE, provider edge device). In many cases, IP services will be supported already in the access tier for horizontal X2/Xn traffic flows, resiliency, and security. Central IPsec GW (SEG) and gnB-CU (Centralized Unit) from the mobile network elements would also often be located in the distribution tier (with central SEG alterna- tively on the core tier). QoS-, security-, and resiliency-related configurations need to be implemented on the edge devices as well as on any access tier hubs. WDM access links may also terminate here and interface the IP service router for horizontal connectivity and locally processed traffic flow (gNB-CU). Statistical multiplexing is possible, with the condition that not all access links need full bandwidth at the same instant. The backbone/core tier is a high capacity, resilient, and secure fast backbone opti- mized for wide area/countrywide connectivity t