A NEAR-OPTIMAL BROADCASTING PROTOCOL FOR MOBILE VIDEO-ON-DEMAND

2009 ◽  
Vol 20 (01) ◽  
pp. 45-55
Author(s):  
REGANT Y. S. HUNG ◽  
H. F. TING
Keyword(s):  
Video On Demand ◽  
Constant Factor ◽  
Mobile Video ◽  
Bandwidth Requirement ◽  
On Demand ◽  
Small Constant ◽  
Wide Range ◽  
New Type ◽  
Broadcasting Protocol ◽  
Mobile Clients

The advance of wireless and mobile technology introduces a new type of Video-on-Demand (VOD) systems, namely the mobile VOD systems, that provide VOD services to mobile clients. It is a challenge to design broadcasting protocols for such systems because of the following special requirements: (1) fixed maximum bandwidth requirement: the maximum bandwidth required for broadcasting a movie should be fixed and independent of the number of requests, (2) load adaptivity: the total bandwidth usage should be dependent on the number of requests; the fewer the requests the smaller the total bandwidth usage, and (3) clients sensitivity: the system should be able to support clients with a wide range of heterogeneous capabilities. In the literature, there are some partial solutions that give protocols meeting one or two of the above requirements. In this paper, we give the first protocol that meets all of the three requirements. The performance of our protocol is optimal up to a small constant factor.

scholarly journals A Seamless Broadcasting Scheme with Live Video Support

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Zeng-Yuan Yang ◽  
Yi-Ming Chen ◽  
Li-Ming Tseng
Keyword(s):  
Waiting Time ◽  
Real World ◽  
Video On Demand ◽  
Live Video ◽  
The Real ◽  
Bandwidth Requirement ◽  
On Demand ◽  
Constant Bandwidth

Broadcasting schemes, such as the fast broadcasting and harmonic broadcasting schemes, significantly reduce the bandwidth requirement of video-on-demand services. In the real world, some history events are very hot. For example, every year in March, thousands of people connect to Internet to watch the live show of Oscar Night. Such actions easily cause the networks contested. However, the schemes mentioned previously cannot alleviate the problem because they do not support live broadcasting. In this paper, we analyze the requirements for transferring live videos. Based on the requirements, a time skewing approach is proposed to enable the broadcasting schemes to support live broadcasting. However, the improved schemes require extra bandwidth for live broadcasting once the length of live shows exceeds the default. Accordingly, we proposed a scalable binomial broadcasting scheme to transfer live videos using constant bandwidth by increasing clients’ waiting time. When the scheme finds that the length of a video exceeds the default, it doubles the length of to-be-played segments and then its required bandwidth is constant.

THE MATCHED FIELD PROCESSING OF BINAURAL DOLPHIN-LIKE SIGNALS FOR THE DETECTION AND IDENTIFICATION OF BURIED TARGETS

2003 ◽  
Vol 11 (04) ◽  
pp. 521-534 ◽  
Author(s):  
A. TOLSTOY ◽  
W. AU
Keyword(s):  
Real Data ◽  
Constant Factor ◽  
Data Display ◽  
Signal To Noise ◽  
Matched Field Processing ◽  
Detection And Identification ◽  
Small Constant ◽  
Target Template ◽  
New Type ◽  
Target Data

The Matched Field Processing (MFP) approach to be discussed here is intended to extract subtle differences between apparently similar signals. The technique is applied coherently to an array of data, i.e. to two receivers. One of the main advantages to this work is that even though we use MFP, there is no modeling involved. Since the available binaural data are quite limited and show very strong, obviously different returns from all the targets (not the subtle differences realistically expected), we found it necessary to manipulate the data to bring them more into line with expectations. In particular, scattered returns from a drum were reduced, i.e. multiplied by a small constant factor, then added to the scattered returns from bottom-only data using various time shifts. The shifts simulated a family of returns from a low signal-to-noise (S/N) 55 gallon drum target. This family with shifted bottom scattering mimics returns from multiple placements of the targets on the bottom. These new target "data" (comprised of manipulated real data) seem at first glance to be nearly identical to the original bottom-only returns. Thus, the new target data display subtle differences from the bottom-only data. The MFP approach (based on the linear, a.k.a., Bartlett, processor) was then applied to these new "data". They were processed and yielded a target "template" of scattered returns varying as a function of time and frequency characterizing the returns scattered from the drum. Additionally, a similar template was computed for the buried manta-like target data and is seen to be quite different from the drum template. This new type of template can easily be used to detect scattering from particular target types in low S/N situations. It is not proposed that dolphins are using these templates, but, rather, that the templates display scattering characteristics which the dolphins may be using. More data would be extremely useful in determining the templates under a variety of conditions, e.g. for lower S/N levels, different bottom types, targets types, source ranges, depths, and scattering angles, etc.

scholarly journals Hybrid broadcasting protocol for video on demand

1998 ◽  
Author(s):  
Jehan-Francois Paris ◽  
Steven W. Carter ◽  
Darrell D. E. Long
Keyword(s):  
Video On Demand ◽  
On Demand ◽  
Broadcasting Protocol
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