Roundtrip delay time measurement apparatus and method for variable bit rate multimedia data
First Claim
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1. An apparatus for measuring a roundtrip delay time associated with communication of multimedia data, the apparatus comprising:
- a video encoder for encoding multimedia data to produce encoded multimedia data;
a transmission rate controller for controlling transmission rate of the encoded multimedia data according to a transmission rate;
a first sending/receiving unit for sending the multimedia data via a first channel;
a roundtrip delay time (RTT) measuring unit for measuring an instant roundtrip delay time using a receiver report (RR) packet received by the first sending/receiving unit;
a moving average calculating unit for calculating a moving average roundtrip delay time using the measured instant roundtrip delay time; and
a transmission rate estimating unit for estimating the transmission rate using the moving average roundtrip delay time and providing the estimated transmission rate to the transmission rate controller,wherein the moving average calculating unit measures the moving average roundtrip delay time according to;
RTT(t)=(1−
j)·
RTT(t−
1)+j·
RTTnew wherein, the RTTnew denotes a new instant roundtrip delay time, the RTT(t) denotes a roundtrip delay time value obtained by calculating the RTTnew and thereafter calculating the moving average of the RTTnew at time t, and the j denotes a weight for determining an adaptation speed with respect to the network state.
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Abstract
An apparatus for measuring a roundtrip delay time associated with communication of multimedia data is provided. In one embodiment, the apparatus comprises a video encoder for encoding multimedia data to produce encoded multimedia data; a transmission rate controller for controlling transmission rate of the encoded multimedia data according to an effective transmission rate; and a first sending/receiving unit for sending the multimedia data via a first channel.
148 Citations
16 Claims
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1. An apparatus for measuring a roundtrip delay time associated with communication of multimedia data, the apparatus comprising:
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a video encoder for encoding multimedia data to produce encoded multimedia data; a transmission rate controller for controlling transmission rate of the encoded multimedia data according to a transmission rate; a first sending/receiving unit for sending the multimedia data via a first channel; a roundtrip delay time (RTT) measuring unit for measuring an instant roundtrip delay time using a receiver report (RR) packet received by the first sending/receiving unit; a moving average calculating unit for calculating a moving average roundtrip delay time using the measured instant roundtrip delay time; and a transmission rate estimating unit for estimating the transmission rate using the moving average roundtrip delay time and providing the estimated transmission rate to the transmission rate controller, wherein the moving average calculating unit measures the moving average roundtrip delay time according to;
RTT(t)=(1−
j)·
RTT(t−
1)+j·
RTTnewwherein, the RTTnew denotes a new instant roundtrip delay time, the RTT(t) denotes a roundtrip delay time value obtained by calculating the RTTnew and thereafter calculating the moving average of the RTTnew at time t, and the j denotes a weight for determining an adaptation speed with respect to the network state. - View Dependent Claims (2, 3, 4, 5, 6, 9)
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7. A method for measuring a roundtrip delay time of variable bit rate multimedia data received by a receiver in a communication network, the method comprising:
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receiving a receiver report packet of a real-time transport control protocol (RTCP) from a receiver; measuring a moving average roundtrip delay time based on information in the receiver report packet; and estimating the transmission rate using the measured moving average roundtrip delay time, wherein the moving average roundtrip delay time is measured according to;
RTT(t)=(1−
j)·
RTT(t−
1)+j·
RTTnewwherein the RTTnew denotes the new instant roundtrip delay time, the RTT(t) denotes a moving average roundtrip delay time calculated at time t, the RTT(t−
1) denotes a moving average roundtrip delay time calculated at time t−
1, and the j denotes a weight for determining an adaptation speed with respect to the network state. - View Dependent Claims (8, 10, 11, 12, 13, 14)
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15. A system for providing information to measure a roundtrip delay time associated with communication of multimedia data, the system comprising:
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a first sending/receiving unit for receiving encoded multimedia data via a first channel from a second sending/receiving unit; and a channel reporting unit for checking a state of the first channel using a sender report (SR) packet received from the first sending/receiving unit to generate the receiver report (RR) packet, and sending the RR packet to the second sending/receiving unit, wherein a current moving average roundtrip delay time for the encoded multimedia data is measured according to;
RTT(t)=(1−
j)·
RTT(t−
1)+j·
RTTnewwherein the RTTnew denotes a new instant roundtrip delay time, the RTT(t) denotes a moving average roundtrip delay time calculated at time t, the RTT(t−
1) denotes a moving average roundtrip delay time calculated at time t−
1, and the j denotes a weight for determining an adaptation speed with respect to the network state. - View Dependent Claims (16)
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Specification