In the digital television world, an important transformation is represented by the television over IP service. One of the
key factors enabling the spreading of television over IP is represented by the quality. Furthermore, packet loss is
probably the main service degradation source for that services. The proposed approach combines the use of AL-FEC
with the set-up of a transport quality mechanism based on FEC packets prioritization. To AL-FEC packets is assigned a
transfer priority higher than that of the media packets transferred under the best effort paradigm, thus reducing in
congested routers the amount of FEC packet losses. In this way the error correction capability is improved. Furthermore,
as the FEC stream is usually a percentage of the media one, the choice of applying the prioritization to the FEC stream
and not to the whole media allows reducing the impact of prioritization of television service traffic on other types of
traffic, concurrent on the same link. The tests have been performed on a simulated network and on a real IP test-bed. The
results show the effectiveness of the proposed approach with respect the un-prioritized one, allowing to obtain higher
video quality at the same packet loss rate.
The IP television services quality is a critical issue because of the nature of transport infrastructure. Packet loss is the
main cause of service degradation in such kind of network platforms.
The use of forward error correction (FEC) techniques in the application layer (AL-FEC), between the source of TV
service (video server) and the user terminal, seams to be an efficient strategy to counteract packet losses alternatively or
in addiction to suitable traffic management policies (only feasible in "managed networks").
A number of AL-FEC techniques have been discussed in literature and proposed for inclusion in TV over IP
international standards. In this paper a performance evaluation of the AL-FEC defined in SMPTE 2022-1 standard is
Different typical events occurring in IP networks causing different types (in terms of statistic distribution) of IP packet
losses have been studied and AL-FEC performance to counteract these kind of losses have been evaluated. The
performed analysis has been carried out in view of fulfilling the TV services QoS requirements that are usually very
For managed networks, this paper envisages a strategy to combine the use of AL-FEC with the set-up of a transport
quality based on FEC packets prioritization. Promising results regard this kind of strategy have been obtained.
In this contribution the robustness of a novel steganographic scheme based on the generalized Fibonacci sequence
against Chi-square attacks is investigated. In essence, an image is first represented in a basis defined by a
generalized Fibonacci sequence. Then the secret data are inserted by substitution technique into selected bit
planes preserving the first order distributions, and finally, the inverse Fibonacci decomposition is applied to
obtain the stego-image. Secret data are scrambled before the embedding to improve the security of the whole
system. In order to perform Chi-square attacks, the knowledge of both the parameters determining the binary
Fibonacci representation of an image is assumed. Experimental results show that no visual impairments are
introduced and the probability of detecting the presence of hidden data is small even if a modest capacity loss
This paper presents a novel spatial data hiding scheme based on the Least Significant Bit insertion. The bitplane
decomposition is obtained by using the (<i>p</i>, <i>r</i>)<i> Fibonacci</i> sequences. This decomposition depends on two
parameters, <i>p</i> and <i>r</i>. Those values increase the security of the whole system; without their knowledge it is
not possible to perform the same decomposition used in the embedding process and to extract the embedded
information. Experimental results show the effectiveness of the proposed method.