Optical Carriers, SONET, and Modern Telecommunications Networks

Optical Carriers and Telecom Networks

The Optical Carrier networks have evolved over the years to become more flexible, and support greater capacity. A lot of this growth and evolution is driven by a technology called SONET. SONET uses the concept of Optical carrier to transport user traffic.

The SONET hierarchy is classified into multiple levels of optical carriers. The fundamental concept of the SONET structure is the synchronous network where each network element is synchronised with the ones it communicates with. As a result, it is able to multiplex the signals easily and transport the payloads across the network.

The basic unit of the SONET network is not an optical carrier, but an electrical one. This unit is termed as STS-1 or synchronous transport signal level one. This is a 51.84 Mbps packet which is large enough to hold a DS3 signal. This is also the ideal link between the traditional PDH and the modern SONET networks.

Beyond the STS-1, all other units within the SONET network are optical carriers that can be used as large pipes or aggregated smaller pipes. For example, the OC3 basically is the optical version of STS-3 which in turn is three STS-1 pipes merged together. This direct aggregation is one of the best features of the SONET technology.

Within SONET, OC3 consists of 3 STS-1 signals, and hence the bandwidth of the signal is three times STS-1 or 155.52 Mbps. The OC3 signals were traditionally used to connect remote locations; however, today they are used more as an access links between large commercial buildings and central offices. The next important level in SONET is OC12 which has the capacity of four OC3 links. This is typically used by CLECs to connect to ILEC networks as well as to link remote offices to main rings in the service provider network.

The core networks are based on the OC192 links. With a capacity of nearly 10 Gbps, these links are ideal for handling the huge traffic in the backbone networks. Interestingly, the very same T1 signal that originates from the customer that is carried through the OC3 networks is transported on the OC192 rings too. This is why SONET is so popular today.

In conclusion, SONET is the best transport technology in use today. It is versatile and highly scalable. The hierarchy built on the optical carriers allows the SONET network to add and drop payloads without having to carry of a lot of signal reconstruction. This makes SONET so popular among the service providers today.

Comments 1 comment

m main45 5 years ago

Search Optical Carriers for T1 Lines, T3 Lines, OC3's, OC12's, OC48's, OC192's, etc.

Search Optical Carriers for T1 Lines, T3 Lines, OC3's, OC12's, OC48's, OC192's, etc.

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