3,838 research outputs found
Random Linear Network Coding for Wireless Layered Video Broadcast: General Design Methods for Adaptive Feedback-free Transmission
This paper studies the problem of broadcasting layered video streams over
heterogeneous single-hop wireless networks using feedback-free random linear
network coding (RLNC). We combine RLNC with unequal error protection (UEP) and
our main purpose is twofold. First, to systematically investigate the benefits
of UEP+RLNC layered approach in servicing users with different reception
capabilities. Second, to study the effect of not using feedback, by comparing
feedback-free schemes with idealistic full-feedback schemes. To these ends, we
study `expected percentage of decoded frames' as a key content-independent
performance metric and propose a general framework for calculation of this
metric, which can highlight the effect of key system, video and channel
parameters. We study the effect of number of layers and propose a scheme that
selects the optimum number of layers adaptively to achieve the highest
performance. Assessing the proposed schemes with real H.264 test streams, the
trade-offs among the users' performances are discussed and the gain of adaptive
selection of number of layers to improve the trade-offs is shown. Furthermore,
it is observed that the performance gap between the proposed feedback-free
scheme and the idealistic scheme is very small and the adaptive selection of
number of video layers further closes the gap.Comment: 15 pages, 12 figures, 3 tables, Under 2nd round of review, IEEE
Transactions on Communication
Optimized Network-coded Scalable Video Multicasting over eMBMS Networks
Delivery of multicast video services over fourth generation (4G) networks
such as 3GPP Long Term Evolution-Advanced (LTE-A) is gaining momentum. In this
paper, we address the issue of efficiently multicasting layered video services
by defining a novel resource allocation framework that aims to maximize the
service coverage whilst keeping the radio resource footprint low. A key point
in the proposed system mode is that the reliability of multicast video services
is ensured by means of an Unequal Error Protection implementation of the
Network Coding (UEP-NC) scheme. In addition, both the communication parameters
and the UEP-NC scheme are jointly optimized by the proposed resource allocation
framework. Numerical results show that the proposed allocation framework can
significantly increase the service coverage when compared to a conventional
Multi-rate Transmission (MrT) strategy.Comment: Proc. of IEEE ICC 2015 - Mobile and Wireless Networking Symposium, to
appea
Sleep Period Optimization Model For Layered Video Service Delivery Over eMBMS Networks
Long Term Evolution-Advanced (LTE-A) and the evolved Multimedia Broadcast
Multicast System (eMBMS) are the most promising technologies for the delivery
of highly bandwidth demanding applications. In this paper we propose a green
resource allocation strategy for the delivery of layered video streams to users
with different propagation conditions. The goal of the proposed model is to
minimize the user energy consumption. That goal is achieved by minimizing the
time required by each user to receive the broadcast data via an efficient power
transmission allocation model. A key point in our system model is that the
reliability of layered video communications is ensured by means of the Random
Linear Network Coding (RLNC) approach. Analytical results show that the
proposed resource allocation model ensures the desired quality of service
constraints, while the user energy footprint is significantly reduced.Comment: Proc. of IEEE ICC 2015, Selected Areas in Communications Symposium -
Green Communications Track, to appea
Turbo trellis-coded hierarchical modulation assisted decode-and-forward cooperation
Hierarchical modulation, which is also known as layered modulation, has been widely adopted across the telecommunication industry. Its strict backward compatibility with single-layer modems and its low complexity facilitate the seamless upgrading of wireless communication services. The potential employment of hierarchical modulation in cooperative communications has the promise of increasing the achievable throughput at a low power consumption. In this paper, we propose a single-relay aided hierarchical modulation based cooperative communication system. The source employs a pair of Turbo Trellis-Coded Modulation schemes relying on specially designed hierarchical modulation, while the relay invokes the Decode-and-Forward protocol. We have analysed the system’s achievable rate as well as its bit error ratio using Monte-Carlo simulations. The results demonstrate that the power consumption of the entire system is reduced to 3.62 dB per time slot by our scheme
Transmission of variable bit rate video over an Orwell ring
Asynchronous Transfer Mode (ATM) is fast emerging as the preferred information
transfer technique for future Broadband Integrated Services Digital Networks (BISON),
offering the advantages of both the simplicity of time division circuit switched techniques
and the flexibility of packet switched techniques. ATM networks with their inherent rate
flexibility offer new opportunities for the efficient transmission of real time Variable Bit
Rate (VBR) services over such networks. Since most services are VBR in nature when
efficiently coded, this could in turn lead to a more efficient utilisation of network resources
through statistical multiplexing. Video communication is typical of such a service and could
benefit significantly if supported with VBR video over ATM networks. [Continues.
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