Clearly, multimedia networks have to deal with different traffic types, for example, variable bit rate (VBR) streams with very strict packet delay requirements.
The research is focused on selecting the best switching points inside the pre-coded variable bit rate video streams, to facilitate bandwidth scalability among the non-scalable multiple bitstreams.
It has been proved, on the basis of simulation experiments and measurements carried out in networks, that thus defined calls can be described by the Poisson streams characteristics [2, 35, 36] in which variable bit rates of packet streams are replaced by constant bit rates called the equivalent bandwidth [37].
Analytical traffic models are constructed based on the internal structure of the packet stream or the so-called call stream in which a packet stream with a variable bit rate is treated as a single call that is characterized by a constant bit rate and appropriate service time.
These are then strung in together to form a consecutive video stream with variable bit rates.
Unlike the UGS class having the highest priority that constant bandwidth can be achieved by allocating fixed number of slots [1], the two service classes, rtPS and ertPS, that both support the real-time variable bit-rate data streaming require efficient and effective control to achieve QoS guarantees and fairness.
In [12], the authors proposed a rate control algorithm for streaming on-demand scalable variable bit rate (VBR) video over wireless networks.
The VLC encoder maps a symbol U k to a variable length codeword C(U k ), and outputs a bit stream u 1 N =[C(U 1),C(U 2),…,C(U K )]=[u 1,u 2,…,u N ] with bit length (N=sum _{k=1}^{K}{ell left (U_{k}right)}).
The UDP traffic reproduces an uplink high quality video streaming, modeled as an on/off exponential traffic at variable bit rate (VBR).
VUDU employs a carefully-controlled application of HDX by VUDU 9 VBR encoding called Statistical Variable Bit Rate that optimizes the beginning of the movie for quick streaming access and then enforces a peak bit rate limit on the rest of the movie to aid in predictability.
