Roundtrip delay time measurement apparatus and method for variable bit rate multimedia data
OwnerKwang-Deok Seoinventor
Life of this patent
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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.
Claims16
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.
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:
- 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·RTTnew
- wherein 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.
A system for providing information to measure a roundtrip delay time associated with communication of multimedia data, the system comprising:
- 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·RTTnew
- wherein 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.
Dependencies are inferred from the claim text.