1. Field of the Invention
The present invention relates to a mobile communication network, and more particularly to a method and system for inter-working an ANSI type radio access network (RAN) in an Internet Protocol (IP) based core network (CN).
2. Background of the Related Art
The mobile communication network introduced in “TIA/EIA 3G-IOS V4.0.0 V&V Draft 5 November 1999” is composed of a RAN and a CN, each of which is further composed of functional network components for providing mobile communication service. Here, the term IOS (Inter-Operability Specification) is a matching protocol between a Base Station Controller (BSC) and a Mobile Switching Center (MSC). IOS is a radio communication application protocol for conducting call connection and disconnection functions for mobile communication service subscribers.
The CN is established primarily with a circuit switching system based upon time division multiplexing (TDM). The network components that make up the CN are associated with one another with the CN's physical connection and the logical matching protocol.
Thus, a matching standard of a RAN depends on the structure of the relevant CN. A related art CN and RAN are matched by the common-channel signaling method (No. 7) on the TDM based circuit connection.
FIG. 1 illustrates related art stacks of matching protocols between a CN and a RAN. As shown in FIG. 1, in a voice switching service, the CN, which includes a mobile communication network described in “TIA/EIA 3G-IOS V4.0.0 V&V Draft 5 November 1999,” is constructed with a circuit switching network based upon the TDM of the synchronous transfer mode (STM). The CN is connected to the RAN through the trunk line matching based upon the G. 703 pulse code modulation (PCM).
To provide the mobile communication switching service, the signal connection between the CN and the RAN is made through a signal network by the narrow band common-channel signal method (Narrow Band No. 7). Furthermore, the mobile communication call is connected using the IOS for the traffic connection. The voice switching service is provided using the TDM technique of the circuit switching method.
On the other hand, for a data switching service, the CN and the RAN are connected with each other through high-speed packet network matching based upon the Internet Protocol (IP). In other words, for data communication, the radio communication data service is provided using the packet routing technique. Accordingly, different communication networks are established with the CN for the voice switching and for the data service. Thus, user service is provided through dual CN structures.
The related art has various disadvantages. For example, because the CN is constructed based upon the circuit switching network of the STM for the radio communication service, the CN conducts signal transmission control using the narrow band common-channel signal method for the purpose of matching with the RAN, and traffic transfer is made using the circuit transmission based upon TDM. Thus, for the transmission of non real-time transfer objects, such as packets or circuit data, the resource may be wasted due to the ordinary occupation of the virtual circuit.
Furthermore, the basic transfer objects within the RAN are packet-based. However, in order to conduct the inter-working with the CN, an additional process of converting packets for the circuit is required. Accordingly, a complex protocol is required to separately control voice data and packet data.
Also, because the radio communication CN establishes different communication networks for voice switching service and for the data switching service, the dual access method causes burdensome overheads in the CN operation.
Additionally, in order to inter-work the voice switching CN with a packet network such as the Internet, a separate inter-working function (IWF) is necessary and a complex control protocol is required.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.