Backhaul and Access

The need for more bandwidth efficiency is most noticeable in mobile backhaul applications. Changing cell phone habits and the emergence of 3G and 4G technologies have triggered an exponential increase in data content for mobility backhaul. This has created an ongoing need to add more transmission capacity. The rub is that Voice centric SONET/SDH-based networks no longer offer a viable and cost-effective solution to handle the increase in data traffic for backhaul transport.

In the past, addressing increased voice traffic involved simply deploying larger number of T1/E1 circuits between the cell sites and the network core. The generous revenue stream from these voice calls easily justified the cost of additional T1/E1 circuits. In contrast, adding additional data traffic is more complex. Installing more T1/E1 circuits to handle increased data traffic is not cost effective because, compared to voice, data traffic generates a much smaller revenue stream per MB of traffic. The cost effective solution is Ethernet.

JumboSwitch Ethernet-based backhaul transport can easily accommodate data increases with a much smaller incremental increase of backbone bandwidth through the proper use of over-subscription and statistical multiplexing. Industrial hardened JumboSwitch platforms can be deployed in the following two areas to increase overall bandwidth efficiency:

• Terminating T1/E1 circuits over a JumboSwitch GigE platform at the cell sites takes advantage of Ethernet’s statistical multiplexing capabilities to reduce bandwidth needs for backhaul.
• The multi-service JumboSwitch platform can easily support both TDM (T1/E1 over Ethernet) and Ethernet on the same platform to simplify the backhaul traffic.
• Using the JumboSwitch instead of SONET/SDH ADMs at the aggregation points, as shown in the diagram below, reduces overall Capital Expenditure (CAPEX) as well as Operational Expenditure (OPEX).