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Substation Communications
Published in John D. McDonald, Electric Power Substations Engineering, 2017
SONET is a standard for sending digital information over optical fiber. It was developed for the transport of large amounts of telephone and data traffic. The more recent synchronous digital hierarchy (SDH) standard developed by the ITU is built on experience gained in the development of SONET. SONET is used primarily in North America and SDH in the rest of the world. SONET can be used to encapsulate earlier digital transmission standards or used directly to support ATM. The basic SONET signal operates at 51.840 Mbps and is designated synchronous transport signal one (STS-1). The STS-1 frame is the basic unit of transmission in SONET. SONET supports multiples of STS-1 up to STS-3072 (159.252480 Gbps).
Optical networks
Published in Matthew N. O. Sadiku, Optical and Wireless Communications, 2018
The existing networks in North America have three major drawbacks.21 First, a multivendor environment is not feasible for optical transmission because interconnection between different vendors is not possible at the optical interface. Second, the signals must be multiplexed/demultiplexed into asynchronous standard electrical interfaces for interconnection between different vendors, which requires many multiplexers/demultiplexers. Third, the multiplexing hierarchy of DSO (64 kpbs), DS1 (1.544 Mbps), DS2 (6.312 Mbps), and DS3 (44.736 Mbps) has been standardized, but multiplexing hierarchies beyond DS3 are generally proprietary. SONET solves these problems and allows the implementation of a reliable, cost-effective, high speed, and broadband communication network. Thus, the rationale behind SONET includes the following:22Standardization: SONET offers seamless interconnection among carriers without depending on their proprietary capabilities.Bandwidth management: Regardless of carriers, bandwidth can be managed to provide maximum control and support for bandwidth-on-demand services.Universal connectivity: SONET interconnects with a variety of current and emerging carrier services including FDDI, DQDB, SMDS, and ATM.Transmission rate: SONET offers 51.84 Mbps to 2.488 Gbps and can extend to much higher rates.
Optical Fibre Communications
Published in Abdul Al-Azzawi, Photonics, 2017
The optical carrier (OC) is the fundamental unit used in SONET. OC indicates an optical signal and the number following OC represents increments of 51.84 Mbps, the minimum transmission rate. The standard SONET frame format for 51.84 Mbps is called STS-1; the equivalent optical transmission rate is called OC-1. SONET standardizes higher transmission bit rates, OC-N, as OC-3, OC-12, OC-48, and OC-192, which are exact multiples of OC-1 (N × 51.84 Mbps). SONET also standardizes the overhead formats and other details of optical transmission to implement mid-span links between different vendors’ equipment.
Towards POI-based large-scale land use modeling: spatial scale, semantic granularity, and geographic context
Published in International Journal of Digital Earth, 2023
To harmonize POI categories with varying semantic granularities and fuse different POI data sources, a semantic ontology network, SONET, was developed to interlink different POI categories through OSM tags (Palumbo, Thompson, and Thakur 2019). Each POI category was translated into a collection of OSM tags that served as an intermediate semantic bridge to link different POI categories together. The SONET knowledge graph has 16,644 nodes and 113,024 links among them. For example, both Yucatecan Restaurant category from Foursquare and Mexican cuisine category from Wikimapia are translated into <amenity = restaurant; cuisine = mexican; building = retail>. Table 1 showed an example of semantic translation from different category names to a unified collection of OSM tags.