TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI

expensive, fixed delivery and reception installations and high transmission costs in term of
bandwidth consumption. It allows full two-way audio and video communication between several
users.
3.1.3.1.3 Peer-to-peer Video Streaming
The main concept of peer-to-peer computing is that each peer is client and server at the same
time. In this context, the multimedia content playing by the user is shared among peers. Peer-topeer
sharing uses the ‘open-after-downloading’ mode, while peer-to-peer video streaming uses the
‘play-while-downloading’ mode. One of the advantages of peer-to-peer video streaming is that
peers have direct connection to other peers avoiding communication via mediating servers.
Significant research effort has addressed the problem of efficiently streaming multimedia, both
live and on demand using peer-to-peer video streaming. We can found systems like SpreadIt [5] for
streaming live media and CoopNet [6], [7] for both live and on-demand streaming. Both systems
build distribution trees using application-layer multicast while relying on cooperating peers. Video
delivering can be in a multicast [8], [9] model or on demand as presented in [10] and [11]. Peer to
peer layered video is also experienced in the work presented in [12].
3.1.4 Interactive vs. Non Interactive Video Applications
Interactive applications have real-time data delivery constraints. The data sent has a timebounded
usefulness, after this time the received data is useless. In Figure 3-3 we give a brief
classification of packet video applications based on delay and loss requirements over packet
switching network according to the ITU-T recommendation G.1010 [13]. This presents the
classification of performance requirements. In this Figure, various applications can be mapped onto
axes of packet loss and one-way delay. The size and shape of the boxes provide a general indication
of the limit of delay and information loss tolerable for each application class. We can found these
classes of applications.
• Interactive video applications. They need a few milliseconds of transfer delay such as
conversational voice and video, interactive games, etc.
• Responsive video applications. Typically, these applications response in few second,
so that human does not wait for a long time, such as voice and video messaging,
transactions, Web, etc.
• Timely video application. The transfer delay can be about some second, such as
streaming audio and video.
• Non-critical video application. The transfer delay is not a critical for those
applications, such as audio and video download service.
From loss point of view, we can find two types of applications:
• Error sensitive video applications such as highly compressed video.
• Error insensitive video applications such as non-compressed video.
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