Mobile Backhaul

5.6 Summary

In this chapter we have considered transport technologies, systems and other building blocks used in building a MBH network. Wireless solutions, i.e. MWR radios, are very common in lower access and especially in the last mile links to the base station sites where their share is over 50% of all transport solutions. Wire-line solutions are used for the rest of the base station sites Optical access is gradually increasing its role also in access – speed of transition is limited by the big investments needed in cable laying. In aggregation tiers and in the core of MBH network optical transport is the most common solution, and where capacities are high, DWDM system or a native packet optical layer is built. In new packet based MBH networks in all network tiers traffic aggregation, routing and protection (resilience) is based on Layer 2 or Layer 3 nodes, i.e. Ethernet switches and/or IP/MPLS routers; in the highest capacity backbones, optical layer may also partly take care of these functions.

Backhaul network is a great investment for a mobile operator. Utilization of legacy and making the right technology selections that also support the future 4G mobile broadband networks are the key for success. Backhaul technology must also provide opportunity for optimizing operating expenses and setting the right level of user experience. The last mile is the main differentiator between fixed transport and mobile backhaul networks, especially in the future when mobile cell sizes shrink. ...