ITU-T G.711.1: extending G.711 to higher-quality wideband speech

Hiwasaki, Yusuke; Ohmuro, Hitoshi

doi:10.1109/mcom.2009.5273817

Cited by 17 publications

(7 citation statements)

References 2 publications

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“…The voice traffic is encoded into a VoIP flow with ITU-T G.711 [29], with average source bit rate of 64 kbps and the packet size of 160 bytes. The number of nodes is assumed to be 50.…”

Section: Network Coding With Varying Number Of Traffic Flowsmentioning

confidence: 99%

AMCCR: Adaptive Multi-QoS Cross-Layer Cooperative Routing in Ad Hoc Networks

Gawas

Gudino

Anupama

2017

Journal of Computer Networks and Communications

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The cooperative communication technique in an ad hoc network exploits the spatial diversity gains inherent in multiuser systems and mitigates the multipath fading. This technique is necessary but perhaps not sufficient to meet the QoS demands in ad hoc network. This is due to the fact that routing protocol at the network layer is more responsible for the successful packet delivery and QoS support. In this paper, we propose an adaptive multi-QoS cross-layer cooperative routing (AMCCR) protocol that enhances the performance through the cooperation of physical, MAC, and network layers. We first formulate an approach to analyze the channel state variations for effective communication schemes at the physical layer. Secondly, we dynamically select the transmission mode to employ cooperative MAC scheme by exploiting spatial diversity. Thereafter, the network layer chooses an optimized route from source to destination through the selected best relay candidates based on multiple QoS metrics. The paper is further extended to support dual-hop half-duplex communication via selected relay by coding technique. The proposed protocol is validated by extensive simulations and compared with CD-MAC and CODE protocols. The results clearly show that the proposed cooperative cross-layer design approach significantly improves the average delay, throughput, and network lifetime of the system.

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“…The voice traffic is encoded into a VoIP flow with ITU-T G.711 [29], with average source bit rate of 64 kbps and the packet size of 160 bytes. The number of nodes is assumed to be 50.…”

Section: Network Coding With Varying Number Of Traffic Flowsmentioning

confidence: 99%

AMCCR: Adaptive Multi-QoS Cross-Layer Cooperative Routing in Ad Hoc Networks

Gawas

Gudino

Anupama

2017

Journal of Computer Networks and Communications

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“…A feature that is becoming increasingly important as high-fidelity media applications proliferate and speech has to share bandwidth on multiplexed channels is Quality-of-Service (QoS) scalability. ITU-T Recommendation G.711.1 [11], [12] is a backwards-compatible extension of G.711 that supports 16 Ksps (7 KHz bandwidth) "wideband" speech while generating a layered (multiple bit rate) codestream that contains an embedded 8 Ksps G.711-compliant narrowband bitstream. This is done using a two-channel, 32-tap linear phase pseudo quadrature mirror filter (PQMF) bank to split the wideband input into 8 Ksps lowpass and highpass subbands.…”

Section: Background On Multirate Filter Banks In Digital Coding Smentioning

confidence: 99%

Group-Theoretic Structure of Linear Phase Multirate Filter Banks

Brislawn

2013

IEEE Trans. Inform. Theory

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Unique lifting factorization results for group lifting structures are used to characterize the grouptheoretic structure of two-channel linear phase FIR perfect reconstruction filter bank groups. For Dinvariant, order-increasing group lifting structures, it is shown that the associated lifting cascade group C is isomorphic to the free product of the upper and lower triangular lifting matrix groups. Under the same hypotheses, the associated scaled lifting group S is the semidirect product of C by the diagonal gain scaling matrix group D. These results apply to the group lifting structures for the two principal classes of linear phase perfect reconstruction filter banks, the whole-and half-sample symmetric classes. Since the unimodular whole-sample symmetric class forms a group, W, that is in fact equal to its own scaled lifting group, W = S W , the results of this paper characterize the group-theoretic structure of W up to isomorphism. Although the half-sample symmetric class H does not form a group, it can be partitioned into cosets of its lifting cascade group, C H , or, alternatively, into cosets of its scaled lifting group, S H . Homomorphic comparisons reveal that scaled lifting groups covered by the results in this paper have a structure analogous to a "noncommutative vector space."

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“…proportions of conditions in the tests). To support the variation issue, the subjective MOS values from difference laboratories and languages can be shown as the evidence, as in Table III that adopted from [23][24].…”

Section: B Subjective Voice Quality Measurement and E-modelmentioning

confidence: 99%

VoIP quality measurement: Enhanced E-model using bias factor

Daengsi

Wuttidittachotti

2013

2013 IEEE Global Communications Conference (GLOBECOM)

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To enhance the standard E-model, this paper proposes the new factor called Bias factor. Based-on the Thai environment, this factor can be computed by subtracting the subjective test results using conversation tests with native Thai users from the objective test results using an E-model tool. Both E-mode tests and conversation tests were conducted with the same VoIP system and test conditions. Then, the enhanced E-model using the Thai bias factor was evaluated with the test set from other groups of native Thai users. After evaluation, it has been found that the enhanced E-model can gain higher confidence. It delivers improved accuracy and reliability at approximately more than 20% when compared to the standard E-model.

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ITU-T G.711.1: extending G.711 to higher-quality wideband speech

Cited by 17 publications

References 2 publications

AMCCR: Adaptive Multi-QoS Cross-Layer Cooperative Routing in Ad Hoc Networks

AMCCR: Adaptive Multi-QoS Cross-Layer Cooperative Routing in Ad Hoc Networks

Group-Theoretic Structure of Linear Phase Multirate Filter Banks

VoIP quality measurement: Enhanced E-model using bias factor

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