What is the difference between SONET and DWDM?

Let us understand what Synchronous optical networking (SONET) is.


SONET stands for Synchronous optical networking. It is a standardized digital connection protocol that can share a huge volume of data over relatively long distances using a fiber optic medium. In SONET, there are various digital data streams are shared simultaneously over optical fiber utilizing LEDs and laser beams.

SONET provides multiple data streams at the same time. It was created to support efficient services in telecommunication systems and thus became widely adopted. SONET uses standardized costs so that all types of organizations can be interconnected.

In packet-oriented networks, a single packet normally includes two parts such as the data header and the payload. During transmission, the data header is shared first and then the payload is sent. With SONET, however, a slight change is created. The header is defined as overhead and is not sent before the payload.

SONET has generally transmitted data at speed between 155 megabits per second and 2.5 gigabits per second. It can construct these high bandwidth data streams, SONET is multiplexer channels having the bandwidth as low as around 64-kilobits per second into data frames transmitted at constant intervals.


DWDM represents Dense Wavelength Division Multiplexing. It is a technology in which several optical signals (laser light) of multiple wavelengths or colors are combined into one signal and are sent over the connecting channel to a lengthy area.

When the optical signal transmission distance changes into thousands of kilometers, few signal losses will occur. It can satisfy this signal fall, optical fiber amplifiers are utilized in the DWDM transmission system.

The DWDM technology requires this gain bandwidth to send multiple optical signals together effectively. DWDM can address up to 80 channels (80 optical signals) with 100 GHz (0.8 nm) spacing.

Dense Wavelength Division Multiplexing (DWDM) is an optical multiplexing technology that can improve bandwidth over current fiber networks. DWDM task operates by joining and transmitting several signals concurrently at multiple wavelengths on the same fiber. The technology generates several virtual fibers, therefore magnifying the capacity of the physical channel.

DWDM is treated as one of the best technologies to increase bandwidth over a current fiber plant. It allows one to generate several “virtual fibers” over one physical fiber. It does this by transmitting several wavelengths (or colors) of light down a bit of fiber.

DWDM was originally adopted by high distance carriers because the spending in amplification, dispersion compensation, and regeneration collected most of the network supplied cost in regional and national SONET networks. DWDM became increasingly famous in metro networks when the local exchange carriers produced their networks.