Synchronous Digital Hierarchy
E719378
Synchronous Digital Hierarchy (SDH) is an international standard for high-speed fiber-optic telecommunications that provides a flexible, synchronous framework for transporting digital signals in public and private networks.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Synchronous Digital Hierarchy canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T8204401 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Synchronous Digital Hierarchy Context triple: [SONET, compatibleWith, Synchronous Digital Hierarchy]
-
A.
SONET
SONET (Synchronous Optical Network) is a standardized digital communication protocol used to transmit large volumes of data over optical fiber in high-speed telecommunications networks.
-
B.
Signaling System No. 7
Signaling System No. 7 is a global telecommunications signaling protocol suite used to set up and manage telephone calls and other services across digital networks.
-
C.
ITU-T G.826 series
The ITU-T G.826 series is a set of international telecommunications standards that define performance and synchronization requirements for digital networks, particularly for timing and packet-based transport.
-
D.
ISDN
ISDN (Integrated Services Digital Network) is a set of communication standards for digital transmission of voice, video, and data over traditional telephone networks.
-
E.
synchronous Ethernet
Synchronous Ethernet is a telecommunications technology that extends traditional Ethernet by adding precise frequency synchronization capabilities for carrier-grade transport networks.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Synchronous Digital Hierarchy Target entity description: Synchronous Digital Hierarchy (SDH) is an international standard for high-speed fiber-optic telecommunications that provides a flexible, synchronous framework for transporting digital signals in public and private networks.
-
A.
SONET
SONET (Synchronous Optical Network) is a standardized digital communication protocol used to transmit large volumes of data over optical fiber in high-speed telecommunications networks.
-
B.
Signaling System No. 7
Signaling System No. 7 is a global telecommunications signaling protocol suite used to set up and manage telephone calls and other services across digital networks.
-
C.
ITU-T G.826 series
The ITU-T G.826 series is a set of international telecommunications standards that define performance and synchronization requirements for digital networks, particularly for timing and packet-based transport.
-
D.
ISDN
ISDN (Integrated Services Digital Network) is a set of communication standards for digital transmission of voice, video, and data over traditional telephone networks.
-
E.
synchronous Ethernet
Synchronous Ethernet is a telecommunications technology that extends traditional Ethernet by adding precise frequency synchronization capabilities for carrier-grade transport networks.
- F. None of above. chosen
Statements (53)
| Predicate | Object |
|---|---|
| instanceOf |
digital transmission hierarchy
ⓘ
fiber-optic transport technology ⓘ telecommunications standard ⓘ |
| abbreviation | SDH NERFINISHED ⓘ |
| basedOn | synchronous multiplexing ⓘ |
| comparedWith | SONET NERFINISHED ⓘ |
| compatibility | interoperable with SONET at interface level ⓘ |
| designedFor |
high-speed fiber-optic telecommunications
ⓘ
private telecommunications networks ⓘ public telecommunications networks ⓘ |
| frameDuration | 125 microseconds ⓘ |
| frameStructure | 9-row by 270-column STM-1 frame ⓘ |
| geographicalUse | primarily outside North America ⓘ |
| hasBasicRate | STM-1 NERFINISHED ⓘ |
| hasBasicRateBitrate | 155.52 Mbit/s ⓘ |
| hasHigherOrderRate |
STM-16
NERFINISHED
ⓘ
STM-256 NERFINISHED ⓘ STM-4 ⓘ STM-64 ⓘ |
| hasOverheadType |
line overhead
ⓘ
path overhead ⓘ section overhead ⓘ |
| hasStandardSeries |
ITU-T G.707
NERFINISHED
ⓘ
ITU-T G.708 NERFINISHED ⓘ ITU-T G.709 NERFINISHED ⓘ ITU-T G.783 NERFINISHED ⓘ ITU-T G.784 NERFINISHED ⓘ ITU-T G.803 NERFINISHED ⓘ |
| introducedIn | late 1980s ⓘ |
| keyFeature |
flexible multiplexing of digital signals
ⓘ
network management capabilities ⓘ standardized optical carrier rates ⓘ support for protection and restoration mechanisms ⓘ synchronous transmission framework ⓘ |
| relatedTo | Synchronous Optical Network NERFINISHED ⓘ |
| replaced | Plesiochronous Digital Hierarchy NERFINISHED ⓘ |
| standardizedBy | ITU-T NERFINISHED ⓘ |
| supportsProtectionScheme |
1+1 protection
ⓘ
1:N protection ⓘ ring protection ⓘ |
| supportsSignalType |
ATM traffic
ⓘ
IP traffic over SDH ⓘ PDH tributaries ⓘ |
| supportsTopology |
mesh topology
ⓘ
point-to-point topology ⓘ ring topology ⓘ |
| synchronizationSource | primary reference clock ⓘ |
| usedIn |
backbone networks
ⓘ
long-haul transmission systems ⓘ metropolitan area networks ⓘ |
| usesMultiplexingStructure |
Administrative Unit
ⓘ
Tributary Unit ⓘ Virtual Container ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Synchronous Digital Hierarchy Description of subject: Synchronous Digital Hierarchy (SDH) is an international standard for high-speed fiber-optic telecommunications that provides a flexible, synchronous framework for transporting digital signals in public and private networks.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.