Method and apparatus for time alignment along a multi-node communication link
View Patent ↗A network entity, which comprises an input configured to receive from an upstream network entity a stream of first media data elements; an output configured to release towards a downstream network entity a stream of second media data elements; a processing engine configured to effect processing tasks on the first media data elements, thereby to generate the second media data elements, the processing tasks being effected in a set of processing intervals; and a control entity. The control entity is configured for receiving a request for a first phase adjustment from the downstream network entity; modifying the set of processing intervals in which are effected the processing tasks in an attempt to accommodate the first phase adjustment; determining a second phase adjustment based on arrival characteristics of the first media data elements and the modified set of processing intervals; and releasing towards the upstream network entity a request for the second phase adjustment.
1. A network entity, comprising:
an input configured to receive from an upstream network entity a stream of first media data elements;
an output configured to release towards a downstream network entity a stream of second media data elements;
a processing engine configured to effect processing tasks on the first media data elements, thereby to generate the second media data elements, the processing tasks being effected in a set of processing intervals;
a control entity configured for:
receiving a request for a first phase adjustment from the downstream network entity;
modifying the set of processing intervals in which are effected the processing tasks in an attempt to accommodate the first phase adjustment;
determining a second phase adjustment based on arrival characteristics of the first media data elements and the modified set of processing intervals;
releasing towards the upstream network entity a request for the second phase adjustment.
2. The network entity defined in claim 1 , wherein each of the processing intervals in the set of processing intervals is associated with a respective duration and a respective activation instant, wherein the control entity is configured to modify the set of processing intervals in which are effected the processing tasks by modifying at least one of the duration and the activation instant of at least one of the processing intervals in the set of processing intervals.
3. The network entity defined in claim 1 , further comprising an input buffer for storing the first media data elements upon receipt from the upstream network entity and prior to processing by the processing engine.
4. The network entity defined in claim 3 , further comprising an output buffer for storing the second media data elements after generation by the processing engine and prior to release towards the downstream network entity.
5. The network entity defined in claim 1 , wherein the control entity implements a scheduler for performing said modifying.
6. The network entity defined in claim 1 , wherein the processing tasks include at least one of speech coding, speech decoding, voice enhancement, noise suppression and automatic gain control (AGC).
7. The network entity defined in claim 1 , wherein the media comprises speech.
8. The network entity defined in claim 1 , wherein the media comprises data other than speech.
9. The network entity defined in claim 1 , wherein the processing tasks are effected periodically.
10. The network entity defined in claim 1 , wherein the processing tasks are effected periodically with a period of 20 milliseconds.
11. The network entity defined in claim 1 , wherein the arrival characteristics of the first media data elements comprise arrival times of the first media data elements within respective fixed-duration periods.
12. The network entity defined in claim 11 , wherein the control entity is further configured to reduce the first phase adjustment by an integer multiple of said period when the first phase adjustment exceeds said period.
13. The network entity defined in claim 11 , wherein the second media data elements exhibit a correspondence with the first media data elements.
14. The network entity defined in claim 13 , wherein the correspondence with the first data elements is one-to-one.
15. The network entity defined in claim 13 , wherein the correspondence with the first data elements is many-to-one.
16. The network entity defined in claim 13 , wherein the correspondence with the first data elements is one-to-many.
17. The network entity defined in claim 16 , wherein each of the second media data elements is generated from a pair of the first media data elements.
18. The network entity defined in claim 1 , wherein said first media data elements or said second media data elements are Internet Protocol packets or Asynchronous Transfer Mode cells.
19. The network entity defined in claim 1 , wherein said first media data elements or said second media data elements are Time Division Multiplexed frames.
20. A method, comprising:
a) at a first network entity:
receiving a stream of first media data elements and releasing towards a downstream network entity a stream of second media data elements;
effecting first processing tasks on the first media data elements, thereby to generate the second media data elements, the first processing tasks being effected in a set of first processing intervals;
receiving a request for a first phase adjustment from the downstream network entity;
modifying the set of first processing intervals in which are effected the first processing tasks in an attempt to accommodate the first phase adjustment; and
determining a second phase adjustment based on arrival characteristics of the first media data elements and the modified set of first processing intervals;
b) at a second network entity:
receiving a stream of original media data elements and releasing the stream of first media data elements;
effecting second processing tasks on the original media data elements, thereby to generate the first media data elements, the second processing tasks being effected in a set of second processing intervals; and
modifying the set of second processing intervals in which are effected the second processing tasks in an attempt to accommodate the second phase adjustment.
21. A method, comprising:
a) at a first network entity:
receiving a stream of first media data elements;
effecting first processing tasks on the first media data elements, the first processing tasks being effected in a set of first processing intervals;
determining a first phase adjustment based on arrival characteristics of the first media data elements and the set of first processing intervals;
b) at a second network entity:
receiving a stream of original media data elements and releasing the stream of first media data elements;
effecting second processing tasks on the original media data elements, thereby to generate the first media data elements, the second processing tasks being effected in a set of second processing intervals;
modifying the set of second processing intervals in which are effected the second processing tasks in an attempt to accommodate the first phase adjustment;
determining a second phase adjustment based on arrival characteristics of the original media data elements and the modified set of second processing intervals; and
releasing towards an upstream network entity a request for the second phase adjustment.