Outline a system to support a distributed music rehearsal facility. Suggest suitable QoS requirements and a hardware and software configuration that might be used.

What will be an ideal response?

This is a particularly demanding interactive distributed multimedia application. Konstantas et al. [1997] report that a round-trip delay of less than 50 ms is required for it. Clearly, video and sound should be tightly synchronized so that the musicians can use visual cues as well as audio ones. Bandwidths should be suitable for the cameras and audio inputs used, e.g. 1.5 Mbps for video streams and 44 kbps for audio streams. Loss rates should be low, but not necessarily zero.
The QoS requirements are much stricter than for conventional videoconferencing – music performance is impossible without strict synchronization. A software environment that includes QoS management with resource contracts is required. The operating systems and networks used should provide QoS guarantees. Few general-purpose OS’s provide them at present. Dedicated real-time OS’s are available but they are difficult to use for high-level application development.
Current technologies that should be suitable:

• ATM network.

• PC’s with hardware for MPEG or MJPEG compression.

• Real-time OS with support for high-level software development, e.g. in CORBA or Java.