(Telecompaper) BT has signed a new 10-year contract with Telefonica UK to support the launch of 4G service for O2 mobile customers. BT will build a new high-capacity transmission network for O2. The new managed network platform from BT Wholesale will provide O2 with the network capacity required to support the increasing demands of customers choosing its planned 4G services. BT will also provide O2 with a sizeable increase in backhaul capacity by delivering the high-speed mobile backhaul links between its mobile base stations and the new transmission network.