1. A mobile terminal for a wireless telecommunications system, comprising: a software services component, said software services component having a software architecture further comprising: software organized in a plurality of software layers arranged in order from software layers providing higher level services to software layers providing lower level services; at least one software module in each software layer; an interface means for permitting communication among software modules in said plurality of software layers pursuant to a set of defined dependency rules; wherein the interface means comprises a Software Back Plane for each software layer, each Software Back Plane having interfaces with the at least one module in its respective software layer, and wherein the set of defined dependency rules includes a rule that a software module in a software layer may only invoke functionality in an interface in its own Software Back Plane or in Software Back Planes of software layers below its own Software Back Plane, and a rule that a software module may never invoke functionality in an interface in a Software Back Plane of a software layer above its own software layer.