INTRODUCTION
A mobile virtual reality service (VRS) will make the presence and presentation of the sounds and sights of an actual physical environment virtually available everywhere in real time through the use of mobile telecommunication devices and networks. Furthermore, the VRS is the conversion of a physical system into its digital representation in a three-dimension (3D) multimedia format. This paper addresses one aspect of the notion of bringing an actual multimedia environment to its virtual presence everywhere in real time .An international telecommunication union (ITC) recommendation document, containing ITUâ„¢s visions on mostly forward-looking and innovative services and network capabilities, addresses the capability needed in a telecommunication system to allow mobile access to real-time sights and sounds of an actual physical environment in the contest and forms of a VRS episode .
Presently, the availability of a VRS is limited to fixed-access phenomena in non-real time , for example , entertainment machines and various simulations equipment. There are also some limited fixed-access and real-time services that require low data transmission rates, such as net meetings. In the latter case, a user can experience a limited real-life environment as opposed to the former case of a non-real-life computer-generated environment. These existing virtual reality services do not allow user control in viewing 3D environments, and they are generally limited to viewing images on a monitor in two dimensions. The VRS-capable systems, however, will allow rather 3D representations of remote real-life environments. For instance, a passenger in a train or in a car could become a participant in a conference call in a 3D environment or become virtually present among the audience in a concert hall or sports stadium viewing a live concert or event.
There are a few obstacles and bottlenecks to the realization of such VRS-capable systems. The development of real-time mobile 3Denvironments requires:
¢ Super-high-speed data transmission rate capability for data streaming.
¢ Highly complex and sophisticated user equipment for user access, and
¢ An advanced signaling and controlling data network.
The advanced signaling and controlling data network is for initiating, establishing, maintaining, and terminating VRS episodes. Exponential increases in data transmission rates and innovative advances in development of terminal equipment are paying the way for the provision of the VRS and the creation of VRS episodes in the near future. Furthermore,the realization of the VRS assumes that the high-tech industry will deliver super high data rate(SHDR) transmission equipment offering a transmission speed of equal to or higher than one gigabit per second to a single user or end point . The anticipated demand for data transmission speed in 2005 will be higher than 20 M/s, upgraded from todayâ„¢s third-generation planned 2 Mb/s. the transmission speed requirements for the so-called fourth generation systems in 2007 are expected to reach near 100 Mb/s. At these rates, telecommunication equipment should be able to transmit, transport, and receive sights and sounds of real-life environment for establishing a VRS episode.
The development of the core signaling and controlling network and its associated software platforms for VRS episode control and for terminal and end-user equipment mobility management is viewed as a major challenge in terms of its control logic and its application programming interfaces for provisioning of the VRS. This paper addresses the core network sub-system for VRS episode control. Several VRS use cases are presented first, and major issues for realization of the VRS are identified. The paper then proposes a solution scheme for the core network signaling and the VRS episode control. The final section of the paper describes an implementation scenario along with an example of signaling flows for establishing and controlling episodes.
