Enhanced packet loss recovery for real time PC-based GigE vision AVI systems

2015 ◽  
Vol 14 (4) ◽  
pp. 433
Author(s):  
Khaled Taouil ◽  
Tarek Jellad ◽  
Zied Chtourou
Keyword(s):  
Real Time ◽  
Packet Loss ◽  
Loss Recovery

Quality Analysis of VoIP in Real-Time Interactive Systems over Lossy Networks

2015 ◽  
pp. 261-274
Author(s):  
Maha Z. Mouasher ◽  
Ala' F. Khalifeh
Keyword(s):  
Real Time ◽  
Packet Loss ◽  
Interactive Systems ◽  
Quality Analysis ◽  
The Internet ◽  
Test Bed ◽  
Lossy Networks ◽  
Packet Losses ◽  
Perceptual Evaluation ◽  
Voice Packets

Voice over Internet Protocol (VoIP) systems have been spreading massively during the recent years. However, many challenges are still facing this technology among which is the lossy behavior and the uncontrolled network impairments of the Internet. In this chapter, the authors design and implement a VoIP test-bed utilizing the Adobe Real-Time Media Flow Protocol (RTMFP) that can be used for many voice interactive applications. The test-bed was used to study the effect of changing some voice parameters, mainly the encoding rate and the number of frames per packet as function of the network packet loss. Several experiments were conducted on several voice files over different packet losses, concluding in the best combination of parameters in low, moderate, and high packet loss conditions to improve the performance of voice packets measured by the Perceptual Evaluation of Speech Quality (PESQ) values.

Evaluating The Performance for DCF Protocol and EDCA Protocol

2015 ◽  
Vol 72 (5) ◽  
Author(s):  
Ahmed Abu-Khadrah ◽  
Zahriladha Zakaria ◽  
Mohdazlishah Othman
Keyword(s):  
Real Time ◽  
Packet Loss ◽  
Area Network ◽  
Distributed Coordination ◽  
Data Types ◽  
End To End Delay ◽  
Main Challenge ◽  
Qos Parameters ◽  
End To End ◽  
Coordination Function

Nowadays supporting quality of service (QOS) for real time application is the main challenge of the wireless area network. 802.11standards use distributed Coordination Function (DCF) protocol and Enhanced Distributed Channel Access (EDCA) protocol in the MAC layer. DCF protocol has only one queue for different data types, it deals with data depending on the arriving time. There is no priority to serve real time applications faster. However EDCA protocol has four queues and each queue works with specific data type. Voice, video, best effort and background are the different queues in the EDCA protocol. Different parameters and priorities are defined for each queue. The voice queue reserves the highest priority and serves its data first. In this paper QOS parameters are measured for both DCF and EDCA protocol by using OPNET simulation. The QOS parameters must reach the requirements to support QOS. The results show how QOS parameters do not reach the requirements when using DCF protocol. The values of the end to end delay and the packet loss percentage are 0.514second, 19.04% respectively. But, when using EDCA protocol the end to end delay becomes 0.0624 second and the percentage of the packet loss decreases until reach 0.00617%. So the QOS parameters achieve requirements with EDCA protocol and support QOS.

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