1. Proposed requirements to CPE for a dynamic QoS control scheme based on RACF Oct. 2006 TTC

2. 2 Introduction Two contributions [1-2] regarding a dynamic QoS control scheme based on RTP/RTCP were discussed at Q.4/13 The work item is on dynamic QoS control based on RTCP reports (with possible extensions) or similar mechanisms in the network as related to RACF and Y.mpm. [1] H. YAMADA and S. UEMURA, “Proposal for initiation of a study of the quality control scheme for service sessions based on (S/BC) functions,” SG13 Delayed Contribution D581, Geneva, July 2006. [2] S. UEMURA and H. YAMADA, “A QoS notification scheme for end-to-end service session quality control,” SG13 Delayed Contribution D583, Geneva, July 2006. [1] H. YAMADA and S. UEMURA, “Proposal for initiation of a study of the quality control scheme for service sessions based on (S/BC) functions,” SG13 Delayed Contribution D581, Geneva, July 2006. [2] S. UEMURA and H. YAMADA, “A QoS notification scheme for end-to-end service session quality control,” SG13 Delayed Contribution D583, Geneva, July 2006. To clarify the necessary functions of functional entities for a dynamic QoS control scheme In the last Study Group 13 meeting in Geneva, July 17-28, 2006

3. 3 QoS control scheme in RACF Service Control Functions RACF Transport Functions (1) (2) (3) Service Control Functions RACF Transport Functions (4) (6)(5) (1) (2) (3) Figure1: push mode Figure2: pull mode CPE Push mode and Pull mode are supported in the RACF document Both of them invoke the QoS control procedure with the request from CPE  resource reservation  resource modification RACF

4. 4 Requirement to CPE for dynamic QoS control QoS request QoS control procedure CPE should transmit the QoS request to SCFs or TFs based on a certain trigger  What is an appropriate trigger for CPE? We believe that the application quality on the endpoint is an appropriate trigger for CPE For dynamic QoS control CPESCFs Figure3: push modeFigure4: pull mode Trigger QoS request QoS control procedure CPETFs Trigger

5. 5 Application quality assessment in CPE Application quality in endpoint is the most important factor when deciding whether CPE should transmit the QoS request ITU-T Rec. P.564 reveals voice quality simply using a set of impairment parameters that can be observed in an IP-layer A set of impairment parameters, such as packet loss, delay, and jitter used in P.564, are included in RTCP XR metrics Application quality assessment In order to verify the quality assessment, 880 speech data generated by using Gilbert Elliot channel model were used Estimation accuracy was tested by comparing the estimated MOS-LQO with MOS-LQO calculated by P.862.1(PESQ) Performance test

6. 6 Application quality assessment in CPE Test results Figure 5: Speech quality assessment using RTCP XR metrics Correlation coefficient is higher than 0.85

7. 7 Application quality assessment in CPE 84% of data are within the error range 97% of data are within the error range Figure 6: Estimation accuracy Test results

8. 8 conclusion CPE should have a function to measure the QoS parameters by using RTCP and RTCP XR QoS parameters measured in CPE can be used as a reliable trigger for QoS control request Suggestions of this contribution