German mobile carrier T-Mobile is showing off the benefits of a converged infrastructure by offloading its 3G backhaul traffic onto sister company T-Com’s network.

As a result of the extra traffic requirements of HSDPA, T-Mobile is ramping up its backhaul infrastructure by deploying gateways from kit vendor RAD Data Communications.

These gateways give T-Mobile the option of connecting HSDPA base stations via low-cost ADSL2+ lines.

A pilot phase in Germany recently concluded and equipment from RAD is also to be used to similar effect in other T-Mobile networks later on.

“HSDPA needs more bandwidth. So T-Mobile wanted an economical solution to expand what are known as the ‘mobile backhaul’ links between base stations and radio network controllers (RNCs),” said Adolf Nadrowski, VP of RAN Strategy at T-Mobile Germany. “It made sense to do without expensive E1 leased lines and, instead, access a very well-developed DSLAM infrastructure and T-Com’s transport networks and buy DSL backhaul as a service.”

The 3rd Generation Partnership Project (3GPP) presently only identifies ATM as the standard technology for UMTS and HSDPA backhaul. And Ethernet-enabled mobile equipment is only gradually being introduced as a platform for packet-switched transport infrastructures. In the meantime, RAD uses pseudowire technology to enable ATM services to be emulated over packet-switched services.