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Avionics Full Duplex Ethernet (AFDX) is a well-established backbone network with wide usage in all current aircrafts, with its first usage onboard the Airbus A380. It was initially defined by Airbus and internationally standardized by ARINC (664 Part 7). The key features are 802.3 Ethernet compatibility, static routing based on a virtual link concept, reserved bandwidth with granted bandwidth allocation...
Based on IEEE 802.15.4, a contention-free period (CFP) adopts guarantee time slot (GTS) mechanism to ensure each device can access the radio channel. However, it is hard to get the authority to access the radio channel due to more competitors access the radio channel simultaneously. To cope with this issue, we proposed a guarantee time slot mechanism to enhance the performance and utilization of using...
Small playback lag in live streaming is important for time-critical and interactive applications such as live stock, market updates, sports and remote education. In this paper, we present Elite addresses the playback lag problem in peer-assisted live streaming systems. Instead of deploying a large initial offset to all the users, Elite seeks the possibility of initializing users with layered proportional...
We study the effect of TCP synchronization on Optical Burst Switched (OBS) networks and its impact on capacity dimensioning. The synchronization of TCP flows appears when a burst with segments from different TCP flows is discarded, making that all TCP flows reduce their transmission rate at the same time, leading to inefficient bandwidth sharing. This paper analyzes the bandwidth capacity that needs...
Ethernet is a popular technology for industrial networking thanks to its low cost and high bandwidth. The current proposals to achieve real-time communication over Ethernet do not consider the determinism of the control applications resulting in inefficient use of bandwidth resources. We proposed a protocol stack architecture that works with standard Ethernet to address this problem. This paper describes...
A clock skew-compensation and/or duty-cycle correction circuit (CSADC) is indispensably required to maximize the performance of synchronous double edge triggered systems. Most conventional CSADCs adopted a cascade structure that inherits a lower performance property so as to slower the locking procedure, meanwhile the dual loop design results in more power consumption and design complexity. A range...
In this paper, we focus on reducing bandwidth utilization and processing cost by minimizing the amount of internal data updates in a distributed data system. The considered system can be a distributed database, a mobile application, or a communication protocol. Our essential approach is to rely on frequent internal updates instead of immediate change notifications to synchronize inter-dependent data...
Nowadays, several live and on-demand streaming solutions use HTTP for signaling and data delivery. A frequently used technique is to chop a continuous stream into segments, encode these in multiple qualities and make these available for download using plain HTTP methods. This approach has become known as dynamic adaptive segment streaming over HTTP. Its advantage is that the deployed web infrastructure...
Because of the asymmetry of paths, the single direction delay becomes more important in network measurement and applications design. We proposed a method to select path for packet sending based on Single Direction Delay Difference (S3D). It can get the shortest single direction delay on the send and receive direction path. This method doesn't need clock synchronization or the exact value of single...
In IPTV networks, channel change latency is a major concern for achieving the desired quality of experience at the subscribers. Since IPTV connections are established over limited capacity links, the number of channels available to each subscriber's use, at any given point in time, is strictly limited. As a direct consequence of this limitation, channel change requests need to go through the IP infrastructure,...
Tactical data links are an essential contribution to automatic "real-time" communication. In the current tactical environment, most users are pre-allocated a fixed amount of bandwidth. As a result, there should be bandwidth wastes and no guarantee of QoS. If the network is flooded, delaying of important messages may happen. So We need proper network management framework in TDL system. And...
Using UWB for wireless short range, low rate communication is attracting growing interest due to its low power consumption and very high bandwidth. Moreover, it is able to offer accurate localization in the range of few centimeters. Regarding these qualities, it is desirable to design a IR-UWB transceiver which consumes as few power as possible when it is applied for battery driven wireless sensors...
The International Society of Automation has recently released ISA100.11a as a standard for reliable and security application in industrial application, in addition to be compatible with existing wired and wireless networks. ISA100.11a, like WirelessHART, uses TDMA scheme in medium access layer to provide deterministic services. However ISA100.11a adopts the CSMA-CA mechanism with priorities for, e...
A multiple-bandwidth 12-bit pipelined analog to digital converter (ADC) with edge-combiner digital delay locked loop for self clock generation and embedded sample & hold (S/H) circuit is presented. The ADC circuit in the proposed design avoids external clock signal for sampling, by generating the clock from analog input signal for a wide range of frequency operation. The proposed design is capable...
Visible light communication networks are currently constrained in range by the divergent source characteristics of the light emmiting diode (LED) and in achievable rate by the modulation bandwidth of the LED transmitter; however, as device advancements improve the limitation on rate becomes inter-symbol interference (ISI). The key contributor to ISI is the non-uniform time of arrival (TOA) of all...
Targeting the distribution of accurate frequency and time references across Packet Switched Networks (PSNs), the IEEE Std 1588™-2008 (a.k.a. 1588V2 or PTPV2) standard specifies network infrastructure components intended to reduce the impact of network elements located between the Grandmaster clock and Slave clocks. Also referred to as On-Path Supports (OPS), these PTPV2 build-in network components...
One of the main topics on the ITU-T study group 15 (SG15/Q13) agenda is defining new network performance limits for recovered timing information across packet networks. The metrics shall apply to the network packet delay variation (PDV) sequence and help in projecting the required system bandwidth given a specific performance envelope. Current ITU-T TDEV-based metrics are based on processing percentiles...
This paper analyzes the deficiency of the average queue calculation in tradition RED queue, and presents a calculation algorithm for the calculation of RED's average queue based on the current network conditions in order to enhance the self-adaptation of RED and we use NS2 for the simulation. Experimental results show that the improved RED performances better than tradition RED in the middle congestion...
One of the major concerns of IPTV network deployment is channel switching (or zapping) delay. This delay can add up to two seconds or more, and its main culprits are synchronisation and buffering. By analysing an extensive dataset - comprising 255 thousand users, 150 TV channels, and covering a 6-month period - we have observed that most channel switching events are linear: it is very common the user...
Quality of Service (QoS) is an important, and admittedly overloaded, concept for emerging services based on the Real-Time Transport Protocol (RTP) to deliver multimedia content. In the context of the Internet Protocol Television (IPTV) services, the synchronization of multimedia components plays an important role. In order to synchronize audio and video components of multimedia content, RTP timestamps...
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