Chapter 11
Summary
Mobile backhaul technology is fast moving from deterministic TDM networks to packet based technologies. This book described this change step by step and function by function. There are many obstacles on the way as little remains the way it used to be in the ‘good old’ TDM. With packet technology the specifications are often not precise and are more dependent on the implementation of vendors.
Explosion of traffic in mobile networks, and mobile broadband specifically requires a high capacity backhaul. At the same time, strict control of backhaul costs are mandated, as the mobile broadband business case is typically based on a fixed monthly charge (‘flat rate’) instead of a per-megabit – charging. For the backhaul this implies that high data amounts need to be carried cost efficiently. Voice and other real-time services then need a premium service over the bulk data transfer, so the packet network needs both low cost bulk data transfer (which drives the capacity) as well as premium bits for voice (which drives the strict QoS).
The quality of service with packet based networks is also not as clearly defined as with TDM, but still typically quite good. If one has a background in TDM networks, it might be a challenge to start thinking packets. Just reading all the standards does not give the big picture of how packet networks work. There are many different specifications of different features, most of which are not used or not implemented ...
