AS9120B, ISO 9001:2015, and FAA AC 0056B ACCREDITED

What Are Modems and How Do They Work?

A modulator - demodulator , more commonly referred to as a modem, is a type of computer device that is capable of transforming digital data into analog signals which can be transferred over phone lines, radio, and more. Commonly used for a number of communication devices and systems ranging from mobile broadband to home computers, modems serve very important roles. In this blog, we will discuss the design, functionality, and types of modems, allowing you to formulate a better understanding of these computer hardware devices.

An analog modem is a common variation of such devices, and they serve to convert digital signals that they receive from a local computer into analog signals that may be optimally relayed to reach another computer or network. When an analog modem converts digital audio, it will modulate it into a frequency that is able to move over analog phone lines, and such frequencies will range between 300 Hz and 3.3 kHz. In order to modulate data, the digital signal is multiplexed with a carrier signal before it is transmitted through a local loop and into a remote station. There, another model will demodulate the analog signal into digital data that can be used by the remote computer.

While the operations of analog modem equipment are fairly simple, such hardware is only capable of transferring data at a speed of 1200 bps. Nowadays, however, modems have become technologically advanced as they have taken advantage of echo canceling, training, quadrature amplitude modulation (QAM), data compression, and much more. With their capabilities, more modern modems feature bolstered speeds that enable larger transfers for the benefit of relaying data. Nevertheless, analog telephone-based modems reached their peak in the 1990s, obtaining the ultimate standard of 56 Kbps. With the subsequent rise of the internet around the same time, modem technology began to shift away from audio-based systems to take advantage of encodings used for cable television lines and telephone line subcarriers.

As of the present, the most popular form of modem found in most settings is the broadband type, that of which was released as a solution to the 56 Kbps peak of older models. Depending on the type of modem and the available network, a broadband modem may rely on various digital subscriber line (DSL) technologies such as ADSL, HDSL, and VDSL. By using DSL, a modem would no longer need to dial for functionality, and the bandwidths typically associated with voice calls were removed. As a result, broadband modems are able to reach much higher speeds and take advantage of higher frequencies.

With the rising popularity and implementation of fiber optic technologies, optical modems are beginning to be developed as well. Such computer hardware devices are known as an optical network terminal (ONT) or optical network unit (ONU), and they may be placed inside or outside a building to achieve “fiber to the home” solutions. With such a modem, the optical medium is transferred to a copper Ethernet interface, and then a router or gateway will ensure that signals are subject to authentication, NAT, routing, and more. With the increased speeds of fiber optics, optical modems can often reach transfer rates upwards of 400 Gbps. While far surpassing the abilities of broadband modems, optical modems are not in common use at this time.

As many home and business networks utilize routers for their ability to distribute internet connections to various devices, some modern modems have taken advantage of router technology to create combination devices. With such a device, one can access a wide area network (WAN) or the internet while ensuring that the device also has the ability to connect to a local area network (LAN) or Wi-Fi network for increased communication.

When you are searching for a modem for your network operations, it is important that you procure one that meets your unique needs and demands. Depending on the speeds that you wish to acquire, some modems may be more advantageous than others. If you are also interested in linking multiple computers together in a local area network while simultaneously accessing the internet, a router and modem combination device may be beneficial for you. Once you have determined the type of modem that you require for your operations, we invite you to begin the procurement process with Fasteners 360.

Fasteners 360 is a premier supplier of aviation, NSN, and electronic parts, and we can help you secure all the modem parts that you need with unmatched pricing and lead-times. All our offered items have been sourced from leading global manufacturers that we trust, and many have undergone rigorous quality assurance measures to ensure their legitimacy and reliability. With 24/7x365 availability of our team members and our simple-to-use RFQ services, customers can request and receive quotes for their comparisons with ease. Begin the procurement process today and see why customers choose to steadily rely on Fasteners 360 for all their operational needs.


Recent Twitter Posts

Semiconductor's Certifications and Memberships
The only independent
distributor with a
  • All orders are fulfilled in the USA.
  • All shipments must comply with U.S.A export laws.
  • No exceptions.
fallen heroes fund logo

“We Proudly Support Intrepid Fallen Heroes Fund that serves United States Military Personal experiencing the Invisible Wounds of War : Traumatic Brain Injury (TBI) and Post Traumatic Stress (PTS). Please visit website ( and help in their valiant effort”.

Thank You for Visiting.

We Hope that You Will Visit Us Again the Next Time You Need NSN Parts and Make Us Your Strategic Purchasing Partner.

Request for Quote

We use cookies to ensure that we give you the amazing experience on our website. If you continue to use this site we will assume that you are happy with it.