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Error resilient video transcoding for robust inter-network communications using GPRS
A novel fully comprehensive mobile video communications
system is proposed in this paper. This system exploits
the useful rate management features of the video transcoders and
combines them with error resilience for transmissions of coded
video streams over general packet radio service (GPRS) mobileaccess
networks. The error-resilient video transcoding operation
takes place at a centralized point, referred to as a video proxy,
which provides the necessary output transmission rates with the
required amount of robustness. With the use of this proposed
algorithm, error resilience can be added to an already compressed
video stream at an intermediate stage at the edge of two or more
different networks through two resilience schemes, namely the
adaptive intra refresh (AIR) and feedback control signaling (FCS)
methods. Both resilience tools impose an output rate increase
which can also be prevented with the proposed novel technique in
this paper. Thus, an error-resilient video transcoding scheme is
presented to give robust video outputs at near target transmission
rates that only require the same number of GPRS timeslots as
the nonresilient schemes. Moreover, an ultimate robustness is
also accomplished with the combination of the two resilience
algorithms at the video proxy. Extensive computer simulations
demonstrate the effectiveness of the proposed system
What Can Wireless Cellular Technologies Do about the Upcoming Smart Metering Traffic?
The introduction of smart electricity meters with cellular radio interface
puts an additional load on the wireless cellular networks. Currently, these
meters are designed for low duty cycle billing and occasional system check,
which generates a low-rate sporadic traffic. As the number of distributed
energy resources increases, the household power will become more variable and
thus unpredictable from the viewpoint of the Distribution System Operator
(DSO). It is therefore expected, in the near future, to have an increased
number of Wide Area Measurement System (WAMS) devices with Phasor Measurement
Unit (PMU)-like capabilities in the distribution grid, thus allowing the
utilities to monitor the low voltage grid quality while providing information
required for tighter grid control. From a communication standpoint, the traffic
profile will change drastically towards higher data volumes and higher rates
per device. In this paper, we characterize the current traffic generated by
smart electricity meters and supplement it with the potential traffic
requirements brought by introducing enhanced Smart Meters, i.e., meters with
PMU-like capabilities. Our study shows how GSM/GPRS and LTE cellular system
performance behaves with the current and next generation smart meters traffic,
where it is clearly seen that the PMU data will seriously challenge these
wireless systems. We conclude by highlighting the possible solutions for
upgrading the cellular standards, in order to cope with the upcoming smart
metering traffic.Comment: Submitted; change: corrected location of eSM box in Fig. 1; May 22,
2015: Major revision after review; v4: revised, accepted for publicatio
PluralisMAC: a generic multi-MAC framework for heterogeneous, multiservice wireless networks, applied to smart containers
Developing energy-efficient MAC protocols for lightweight wireless systems has been a challenging task for decades because of the specific requirements of various applications and the varying environments in which wireless systems are deployed. Many MAC protocols for wireless networks have been proposed, often custom-made for a specific application. It is clear that one MAC does not fit all the requirements. So, how should a MAC layer deal with an application that has several modes (each with different requirements) or with the deployment of another application during the lifetime of the system? Especially in a mobile wireless system, like Smart Monitoring of Containers, we cannot know in advance the application state (empty container versus stuffed container). Dynamic switching between different energy-efficient MAC strategies is needed. Our architecture, called PluralisMAC, contains a generic multi-MAC framework and a generic neighbour monitoring and filtering framework. To validate the real-world feasibility of our architecture, we have implemented it in TinyOS and have done experiments on the TMote Sky nodes in the w-iLab.t testbed. Experimental results show that dynamic switching between MAC strategies is possible with minimal receive chain overhead, while meeting the various application requirements (reliability and low-energy consumption)
EVEREST IST - 2002 - 00185 : D23 : final report
Deliverable pĂșblic del projecte europeu EVERESTThis deliverable constitutes the final report of the project IST-2002-001858 EVEREST. After its successful completion, the project presents this document that firstly summarizes the context, goal and the approach objective of the project. Then it presents a concise summary of the major goals and results, as well as highlights the most valuable lessons derived form the project work. A list of deliverables and publications is included in the annex.Postprint (published version
Final report on the evaluation of RRM/CRRM algorithms
Deliverable public del projecte EVERESTThis deliverable provides a definition and a complete evaluation of the RRM/CRRM algorithms selected in D11 and D15, and evolved and refined on an iterative process. The evaluation will be carried out by means of simulations using the simulators provided at D07, and D14.Preprin
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