An Overlay Architecture for High-Quality VoIP Streams

Amir, Yair; Danilov, Claudiu; Goose, Stuart; Hedqvist, David; Terzis, Andreas

doi:10.1109/tmm.2006.884609

Cited by 50 publications

(36 citation statements)

References 30 publications

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“…Not only their CPU utilization is at 100%, but more importantly the queueing delays experienced by the running processes can be very significant -even up to several seconds between two consecutive accesses to CPU. This results in incorrect propagation time measurements and packet dropping due to incoming buffer overflow at the destination [19,20]. Moreover, the situation changes dynamically.…”

Section: ) Data Setsmentioning

confidence: 99%

Exploiting the Path Propagation Time Differences in Multipath Transmission with FEC

Kurant

2011

IEEE J. Select. Areas Commun.

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Abstract-We consider a transmission of a delay-sensitive data stream from a single source to a single destination. The reliability of this transmission may suffer from bursty packet losses -the predominant type of failures in today's Internet. An effective and well studied solution to this problem is to protect the data by a Forward Error Correction (FEC) code and send the FEC packets over multiple paths. In this paper we show that the performance of such a multipath FEC scheme can often be further improved. Our key observation is that the propagation times on the available paths often significantly differ, typically by 10-100ms. We propose to exploit these differences by appropriate packet scheduling that we call 'Spread'. We evaluate our solution with a precise, analytical formulation and tracedriven simulations. Our studies show that Spread substantially outperforms the state-of-the-art solutions. It typically achieves two-to five-fold improvement (reduction) in the effective loss rate. Or conversely, keeping the same level of effective loss rate, Spread significantly decreases the observed delays and helps fighting the delay jitter.

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Section: ) Data Setsmentioning

confidence: 99%

Exploiting the Path Propagation Time Differences in Multipath Transmission with FEC

Kurant

2011

IEEE J. Select. Areas Commun.

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“…Through mean opinion score (MOS) test results, it was found that FEC performed better than bit rate redundancy. In [4], localized packet loss recovery and rapid rerouting were used in the event of network failures for VoIP packets. The recovery protocols were deployed on the nodes of an application-level overlay network and did not require changes in the underlying infrastructure.…”

Section: Related Workmentioning

confidence: 99%

Improving Quality of VoIP Streams over WiMax

Sengupta

Chatterjee

Ganguly³

2008

IEEE Trans. Comput.

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Abstract-Real-time services such as VoIP are becoming popular and are major revenue earners for network service providers. These services are no longer confined to the wired domain and are being extended over wireless networks. Although some of the existing wireless technologies can support some low-bandwidth applications, the bandwidth demands of many multimedia applications exceed the capacity of these technologies. The IEEE 802.16-based WiMax promises to be one of the wireless access technologies capable of supporting very high bandwidth applications. In this paper, we exploit the rich set of flexible features offered at the medium access control (MAC) layer of WiMax for the construction and transmission of MAC protocol data units (MPDUs) for supporting multiple VoIP streams. We study the quality of VoIP calls, usually given by R-score, with respect to the delay and loss of packets. We observe that loss is more sensitive than delay; hence, we compromise the delay performance within acceptable limits in order to achieve a lower packet loss rate. Through a combination of techniques like forward error correction, automatic repeat request, MPDU aggregation, and minislot allocation, we strike a balance between the desired delay and loss. Simulation experiments are conducted to test the performance of the proposed mechanisms. We assume a three-state Markovian channel model and study the performance with and without retransmissions. We show that the feedback-based technique coupled with retransmissions, aggregation, and variable length MPDUs are effective and increase the R-score and mean opinion score by about 40 percent.

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“…Performance Metrics: The effectiveness of the AWON architecture and the programming interface can be evaluated by measuring the quality of the content delivered to the end users under different network congestion conditions. For most real-time applications, application-specific metrics are used to measure quality of the content; for multimedia applications, these metrics include PESQ [1,19] for voice quality and PSNR [19] for video streaming. For the CASA application we use the standard deviation of the estimated sensed values (specifically, reflectivity and wind velocity) to evaluate quality of the radar data [6,7].…”

Section: Performance Evaluationmentioning

confidence: 99%

“…Overlay networks have been proposed to provide a range of useful services for enhancing QoS for Internet applications including bandwidth guarantees [1,3,11,19,22]. With overlay networking, application-aware processing can be implemented at intermediate nodes, thus significantly enhancing the ability of the application to adapt to network conditions and improve the QoS provided to the end users.…”

Section: Introductionmentioning

confidence: 99%

“…However, adaptive data-selection mechanisms in traditional applications based on end-to-end data delivery relied on end-host applications to adapt to network conditions [2,9,21]. Active networks [20] introduced the concept of innetwork processing, where routers and switches of the network perform customized computations on messages being forwarded.Overlay networks have been proposed to provide a range of useful services for enhancing QoS for Internet applications including bandwidth guarantees [1,3,11,19,22]. With overlay networking, application-aware processing can be implemented at intermediate nodes, thus significantly enhancing the ability of the application to adapt to network conditions and improve the QoS provided to the end users.…”

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confidence: 99%

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An Architecture and a Programming Interface for Application-Aware Data Dissemination Using Overlay Networks

Banka

Lee

Jayasumana

et al. 2007

2007 2nd International Conference on Communication Systems Software and Middleware

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- IntroductionDistributed collaborative adaptive systems relying on the Internet for connectivity are increasingly used for applications such as weather monitoring, industrial environment monitoring, and distributed target tracking [13,16]. In many of these applications, a variety of data must be distributed in real time to multiple end users at distant geographical locations. These data streams and end users may have differing QoS requirements for the data based on the ultimate use of the data. The data-dissemination infrastructure must therefore be able to adapt in an application-specific manner to meet these differing data requirements. Collaborative Adaptive Sensing of the Atmosphere (CASA) [16], an example of these emerging distributed collaborative adaptive systems, is based on a dense network of weather radars that operate collaboratively to detect tornadoes and other hazardous atmospheric conditions. The underlying network infrastructure itself may be affected by such adverse weather conditions, and as such one cannot rely on ISP-provided QoS guarantees or service-level agreements. CASA application software must thus monitor the underlying network, link availability, link quality, and other performance measures, and then use this information to get the best possible service out of the available network facilities. The use of an overlay network paradigm is helpful in meeting such application needs. Application-aware processing such as selective frame discards for video streaming has shown promising results in improving the content quality [9] under congested network conditions. However, adaptive data-selection mechanisms in traditional applications based on end-to-end data delivery relied on end-host applications to adapt to network conditions [2,9,21]. Active networks [20] introduced the concept of innetwork processing, where routers and switches of the network perform customized computations on messages being forwarded.Overlay networks have been proposed to provide a range of useful services for enhancing QoS for Internet applications including bandwidth guarantees [1,3,11,19,22]. With overlay networking, application-aware processing can be implemented at intermediate nodes, thus significantly enhancing the ability of the application to adapt to network conditions and improve the QoS provided to the end users. Examples of these functionalities include application-aware data forwarding and data drops, as well as application-aware rate control during network congestion at intermediate nodes [7]. It is often desirable to use the same overlay infrastructure for multiple simultaneous applications such as weather radar data streaming, and video streaming to multiple end users. A general-purpose overlay architecture that supports deployment of application-aware services on the overlay nodes in the network, and a programming interface required for such services that can leverage such an overlay network infrastructure to support application-specific QoS requirements will significantly enhance the overla...

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An Overlay Architecture for High-Quality VoIP Streams

Cited by 50 publications

References 30 publications

Exploiting the Path Propagation Time Differences in Multipath Transmission with FEC

Exploiting the Path Propagation Time Differences in Multipath Transmission with FEC

Improving Quality of VoIP Streams over WiMax

An Architecture and a Programming Interface for Application-Aware Data Dissemination Using Overlay Networks

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