Voice call continuity (VCC) is a novel mobility scheme for voice communication on call control level. One main use case is to transfer a voice session between CS access and WLAN, however, the solution as currently discussed in standardization is not limited to WLAN, but is restricted to make-before-break type of operation for a domain transfer. This paper provides a description of the current capabilities and limitations of the VCC standards. A possible evolution of the VCC solution has been implemented in a prototype, which realized the transfer of a voice session and a video session in parallel between WLAN and WCDMA, whereby on WCDMA a CS bearer is used for the voice session and a PS bearer is used for the video session.

This paper describes a proposal for the tight-coupling integration of WLAN-based media points and 3GPP/UMTS systems. The approach extends the SIP based session management and mobility management proposed for a standalone media point network by connecting it to the UMTS network. The integration aims to provide seamless continuity for SIP-based services when performing vertical radio handover from UMTS to WLAN. The proposed solution builds largely on existing procedures, like the standard UMTS control plane protocols and the IETF CTP (context transfer protocol). Session continuity is provided by keeping the current local IP address in the user terminal after handover. In order to save battery the usage of 3GPP location service mechanisms is proposed, which allow switching off WLAN modules outside the WLAN coverage area

Future wireless communication systems will be characterised by an integration of different access technologies. Such systems will feature a user-friendly coordination of the complementary access technologies to access personalized services in a seamless manner via the currently most suitable access. Efficient resource management will provide cost effective bandwidth. These systems need a flow-control functionality to select always the best suitable access system for a certain traffic flow in different environments. This paper lists requirements and describes a flow control functionality that controls the forwarding of individual traffic flows over different access systems in a multi-access scenario. In addition, examples are presented and discussed as to how this advanced multimedia flow-control can be embedded both in a co-operative and in an integrated multi-access system architecture, providing thereby guidelines for standardization and future products.

As the demand for high quality asymmetric IP services for mobile users is increasing, research is analysing the suitability of today's wireless network for this services. Additional requirements are imposed by users travelling at a high speed. As it is clear that new spectrum cannot be easily allocated for new communication services to satisfy the capacity and coverage requirements of extremely mobile users, new approaches must be examined to flexible use regionally or temporarily available frequency bands. Hence mobile and legacy applications must deal with the described changing environment through quality-of-service (QoS) adaptation. This requires innovative middleware concepts that allow a simplified mobile application development.

We describe a system for storing, transmitting, and presenting digital movies in a computer network. The hardware used in the system is standard hardware, as found in typical workstations today; no special hardware is required, but if available it can be used to provide better performance. The XMovie system has several innovative features. First, it contains a new algorithm for the gradual adaptation of the color lookup table during the presentation of the movie to ensure optimal color quality on low-end workstations. Second, it is a multistandard system supporting the compression techniques MPEG, Motion JPEG, and a newly developed extension to the well-known Color Cell Compression method. Third, it contains AdFEC, a new adaptable forward error correction method for our movie transmission protocol.

In this paper we describe the tool-supported specification and implementation of a multimedia communication protocol on parallel hardware. MCAM is an application layer protocol for movie control, access and management. We specify the full MCAM protocol together with ISO presentation and session layers in Estelle. Using a code generator, we derive parallel C++ code from the specification. The code is compiled and executed on a multiprocessor system under OSF/1 and on UNIX workstations. Measurements show the performance speedup gained by several different configurations of parallel units. We also report on experiences with our methodology.>

Article Free Access Share on MCAM: an application layer protocol for movie control, access, and management Authors: Ralf Keller View Profile , Wolfgang Effelsberg View Profile Authors Info & Claims MULTIMEDIA '93: Proceedings of the first ACM international conference on MultimediaSeptember 1993 Pages 21–29https://doi.org/10.1145/166266.166268Published:01 September 1993Publication History 11citation477DownloadsMetricsTotal Citations11Total Downloads477Last 12 Months12Last 6 weeks3 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF