Transceiver vs Transponder: What's the Difference?

Photo courtesy of Flickr: Nathan Duprey

In a recent blog post, we discussed transceivers and their role in mobile devices as well as in a server environment. While the article was insightful, it raised some questions that we will seek to answer this go-round. Chiefly, what exactly is the difference between a transceiver and a transponder?

To understand the difference between a transceiver vs. transponder, we need to define what each one does.

What is a Transceiver?

To begin with, a transceiver is a device made up of both a receiver and transmitter (the name "transceiver" is actually short for transmitter-receiver). Its purpose, in broad terms, is to transmit and receive data. There are other functions transceivers serve depending upon the setting in which they are used. In addition to sending information back and forth, they also help direct the flow of traffic, convert data, and even format information as it comes in and out of the pike.

There are many types of transceivers, including optical transceivers, which are used in fiber - optic settings like cable and networking interfaces, as well as XFP, SFP, and SFP+. They come in hot-swappable module form and chipsets as well.

What is a Transponder?

A transponder is a device with many purposes, depending upon the role it is in. Its name is a mix of transmitter and responder, which gives us an idea of its purpose. If used for identification (think of transponders in an airplane setting, for instance), its function is to send out an identifier signal when an outside signal requests identification.

When used in a communication role, a transponder acts as a channel where data such as images, video, and audio can travel. This type of transponder is used for satellites and broadcasting.

More relevant to us, transponders in fiber-optic communication settings (high-speed networking) transmit and receive signals from a fiber.

Wisegeek has a good page of information on transponders, as does Search Mobile Computing.

Sounds pretty similar to transceivers, right? So who wins the battle of transceiver vs. transponder?

What's the Difference?

One way that a transceiver differs from a transponder is through their respective interfaces. A transceiver uses a serial interface, while a transponder uses a parallel interface. This causes a difference in consumption of resources, such as power.

Additionally, transceivers provide an electrical-optical function, while transponders convert between two different optical wavelengths. This has an effect on energy consumption, bandwidth, and data transmission rates as well.

Hopefully this article has gotten you started down the path to fully understanding transceivers, transponders, and the difference between the two, particularly in a networking, Ethernet, or fiber-optic communications setting. In your pursuit of knowledge regarding transceivers and transponders, I suggest that you also read some basic networking articles, such as Microsoft's Explanation of the OSI Model and the IEEE's page on Ethernet Standards. I think you will find this information useful.

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