TITRE Adaptive Packet Video Streaming Over IP Networks - LaBRI

An Object Descriptor (OD) describes each of the three video objects. Table 4-1 summarizes
QoS value for each object.
In our implementation, each MPEG-4 object is modeled by one parameters vector called X ∈
R 3 containing the flowing structure X= (MAX_DELAY, MAX_DELAY - PREF_MAX_DELAY,
LOSS_PROB) T . The first element of the vector specify the maximum end-to-end AU transfer
delay, the delay variation of the AU is calculated by the formula MAX_DELAY -
PREF_MAX_DELAY, the third element is the AU loss ratio.
QoS Metric Object 1
O1
Object 2
O2
Object 3
O3
MAX_DELAY 250ms 200ms 150ms
PREF_MAX_DELAY 200ms 150ms 100ms
LOSS_PROB 2*10 -3 3*10 -3 1*10 -3
Table 4-1: AVO QoS value in QoS_Descriptor
Figure 4-5, shows the throughput of each video object stream used in the experiment. Each
stream is read, classed and marked over IP Diffserv network using the set of tools described above.
We give more details of the marking in the next Chapter.
Throughput (bits/s)
80000
70000
60000
50000
40000
30000
20000
10000
MPEG-4 Video Elementary Streams
MPEG-4 Object 3: The person
MPEG-4 Object 2: The Background
MPEG-4 Object 1: The logo2
0
0 10 20 30 40 50 60
Time (s)
Figure 4-5: Throughput of each MPEG-4 video object
The testbed network is depicted in Figure 4-6. The MPEG-4 server delivers a simulated
MPEG-4 AVOs stream on demand to several heterogeneous receivers. The receiver can be simple
wired or wireless terminals such as a mobile GSM/GPRS/UMTS capable of rendering MPEG-4
video sequences. The network nodes are IP Diffserv compliant routers. We use Linux-based IP
routers with Diffserv implementation as presented in [153], and [154]. The testbed is composed of
tow edge routers and a core router running Linux with IP Diffserv components. All Ethernet links
are 10 Mb/s.
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