Feature Topic: Mobile Backhaul for Small Cells

Post a reply

Natasha Simonovski

Feature Topic: Mobile Backhaul for Small Cells

Tue, 08/27/2013 - 08:35 — Natasha Simonovski

The rapid growth in mobile broadband in recent years is driving operators to improve and densify their Radio Access Network (RAN). It is becoming apparent that due to the scale of densification that will be required, it will be necessary to include small cells as well as macro cells in a heterogeneous network. In order to maximize the end user experience, some level of radio coordination between these small and macro cells is needed - this coordination will be signaled across a mobile backhaul network. Mobile backhaul typically refers to the network between the base station site and the network controller site, but can also include interconnection between base station sites. Mobile backhaul includes a spectrum of networks and network technologies, including the Radio Access Network (RAN) and Core Networks. Part of the challenge is to deliver scalable solutions that can support mobile backhaul for 2G, 3G and 4G networks utilizing services from simple point-to-point connectivity through to virtual private LAN services. Today, this is being achieved using a number of technologies including SDH, ATM, MPLS and Ethernet.

At the same time carriers face the challenge of migrating toward next generation networks with the aim of converging onto networks that contain fewer technologies, avoid single service network solutions, reduce the number of operational support systems and minimise the cost of ownership. In doing so, carriers need to consider how packet services (e.g. Ethernet) will be delivered over these new networks and whether the existing service model will be maintained or modified.

Ethernet's ubiquity in both the enterprise and residential markets, coupled with the universal existence of mature, low-cost technology to implement it, is driving the demand for Ethernet service solutions in the mobile backhaul environment. However, performance requirements to support tight radio coordination between the base stations may push the performance limits of Ethernet Services available today. Further, so-called front haul topologies that split the basestation into a central baseband unit and remote radio units require such very low latency that they can only be met by point-to-point fibre and perhaps microwave.

There is considerable market interest on the development of small cell backhaul solutions that are an evolution of the existing backhaul networks. Various standards bodies such as NGMN, MEF, and BBF are also studying what the implications would be on their defined mobile backhaul network architectures. Synchronisation mechanisms that are being developed for Ethernet networks are key to support the mobile backhaul application. Combined with this there is also activity on the development of fault management solutions to improve fault localisation and speed of response and on developing new network management and control solutions.

Post a reply