Graphics Reference
In-Depth Information
3.2 ScalableVideoCoding
Modernvideotransmissionandstoragesystemsaretypicallycharacterisedbyawiderange
of access networktechnologiesandend-userterminals.Varyingnumbersofusers,eachwith
theirowntimevarying data throughput requirements, adaptively share network resources
resulting in dynamic connection qualities. Userspossess a variety of devices with different
capabilities, ranging from cell phones with smallscreensandrestrictedprocessingpower,
to high-end PCs with high-definition displays. Examples of applications include virtual
collaboration system scenarios, as shown in Figure 3.3, where a large, high powered ter-
minalactsasthemaincontrol/commandingpointandserveagroupofco-locatedusers.The
large terminal may be the headquarters of the organization and consists of communication
terminals,shareddeskspaces,displaysandvarioususerinteractiondevicestocollaboratewith
remotelylocatedpartners.Theremotelylocateduserswithasmall,fixedterminalwillactas
the local contact and provide the local information. Mobile units (distribution, surveying,
marketing, patrolling, etc.) of the organization may use mobile terminals, such as mobile
phones and PDAs, to collaborate with theheadquarters.
