Wireless real-time IP services enabled by header compression

The world of telecommunications is currently going through a shift of paradigm from circuit switched, connection oriented information transfer towards packet switched, connection-less transfer. For application independence and to decrease costs for transport and switching it is attractive to go IP all the way over the air interface to the end user equipment, i.e., to not terminate the IP protocols before the air interface. A major reason to avoid using voice over IP over the air interface has, up to now, been the relatively large overhead imposed by the IP/UDP/RTP headers of voice packets. This paper presents a novel header compression scheme, ROCCO, that can compress the large headers to a minimum of one octet and is robust against the errors imposed by cellular links. Its performance is excellent both in terms of robustness and compression efficiency. Moreover, system capacity simulations are presented, which show that ROCCO gives significantly higher system capacity than the other current header compression candidate, CRTP. Finally it is argued that with ROCCO voice over IP over wireless becomes feasible from a spectrum-efficiency point of view.