Digital telecommunications transmission systems
AssigneeMarconi Communications, Inc.
InventorIain J Slater
Life of this patent
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Abstract
In an SDH telecommunications system, a buffer overfill/underfill problem, which is consequent upon either a synchronization failure or an excessive amount of wander, is overcome by detecting such failure or wander and temporarily changing the mode of operation of a de-synchronizer at a terminating end of the SDH path. A Synchronization Status Messaging Byte (SSMB) is used as an indicator of the quality of the incoming bearer timing.
Claims8
In a Synchronous Digital Hierarchy (SDH) telecommunications system, a method of overcoming a primary rate re-timing buffer overfill/underfill problem consequent upon either a synchronization failure or an excessive amount of wander, said method comprising the steps of:
- a) detecting said failure or wander from a primary rate timing using either a Synchronous Transport Module (STM-N) bearer or an average data rate in response to the quality of incoming bearer timing as represented by a Synchronization Status Messaging Byte (SSMB);
- and
- b) temporarily changing the mode of operation of a de-synchronizer at a terminating end of an SDH path to prevent the overfill or underfill of the primary rate re-timing buffer.
In a Synchronous Digital Hierarchy (SDH) telecommunications system, an apparatus for overcoming a primary rate re-timing buffer overfill/underfill problem consequent upon either a synchronization failure or an excessive amount of wander, said apparatus comprising:
- a) detecting means for detecting said failure or wander, the detecting means including means for deriving a primary rate timing from either a Synchronous Transport Module (STM-N) bearer or an average data rate in response to the quality of incoming bearer timing as represented by a Synchronization Status Messaging Byte (SSMB);
- and
- b) means for temporarily changing the mode of operation of a de-synchronizer at a terminating end of an SDH path in response to the detecting means to prevent the overfill or underfill of the primary rate re-timing buffer.
Dependencies are inferred from the claim text.