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VoIP vs Landline vs Cell Calls: Phone Calling Explained

by Joe DeBari

We make phone calls all the time, but have you ever thought about how they actually work? Here's what makes VoIP vs landline vs cell phone calls different.

March 10, 1876: “Mr. Watson, come here, I want you.”

There’s certainly some controversy over who created the telephone (was it Alexander Graham Bell or Elisha Gray?) and even what Bell said exactly on his first successful phone call (was it “I want you” or “I want to see you?”). But once telephones were created, there’s no doubt about the impact they’ve had on the world. Bell surely couldn’t have imagined that now, people can use smartwatches to make a phone call or even just say, “Alexa, call Grandma,” and voila! There’s Grandma’s voice coming through the tabletop speaker.

Ever wonder how a phone call actually works? Here’s a brief look at what happens while you’re on a call—whether it’s a VoIP call, cell phone call, or a good ol’ POTS (“plain old telephone system”) call.

How Do Landlines Work? Handsets, Copper Wires, and Telephone Lines

While phones are quickly and constantly changing, a basic phone is a simple and complete device. The handset contains a speaker that you place against your ear and a microphone that you position near your mouth. As you speak into the microphone, the sound waves from your voice are transformed into electrical energy.

The humble telephone: handset, cord, and all.

The electrical energy is then transmitted along copper wires that leave the handset (through those infamous coiled cords that connect the handset to the telephone base) and travel along telephone wires and through telephone exchanges until they reach the handset of the person that you are talking to. There, the other person’s speaker transforms the electrical energy into sound waves, reproducing the words that you originally spoke.

And when the other person speaks into their handset’s microphone, the whole process starts over again until you hear those words through your speaker.

How Do Cell Phones Work? Introducing Radio Waves and a Grid System

Cell phones have the same speaker and microphone combination in them. While they still transform your voice’s sound waves into an electrical signal, that signal is sent out from your cell phone over radio waves. When those radio waves are received by the other person’s cell phone, they are converted back into sound waves for that person to hear.

The fascinating part is how those radio waves travel between the caller’s cell phone and the callee’s cell phone. Cell phones connect to their nearest cell phone mast, which is just a massive fixed antenna on the ground. When a cell phone makes a call, the signal is beamed to that particular mast, which then routes the call through a local base station and onto its destination.

Cell phones beam calls over radio waves.

In order to ensure that multiple calls do not interfere with each other, a grid pattern is imposed upon the landscape. Each grid box, known as a “cell,” has its own mast tower in it that collects and routes all calls made from cell phones within that cell. This system enables the same set of radio wave frequencies to be reused in each cell in the grid, exponentially multiplying the amount of calls that the entire grid can handle, while also making sure that all calls remain separate and unscrambled.

How Does VoIP Work? Using an Internet Connection to Transmit a Phone Call

And now we come to VoIP calls, which are revolutionizing business and even residential communications. “Voice over Internet Protocol” transforms the sound waves from your voice into a digital signal and then leverages your Internet connection to transmit that signal over to the other person on the call.

Specialized phones known as IP phones are used with VoIP services; these adapted phone devices look and feel exactly like a regular telephone but connect directly to your modem or router rather than to the phone jack in your wall. These IP phones change the sound waves from your voice into a digital form using computer programs/algorithms known as “codecs.” Each IP phone has its own set of available codecs for use; when two IP phones are connected on a call, they negotiate which codec to use for the call by selecting the best codec that they both have in common.

In addition to IP phones, you can also use softphones and ATA (analog telephone adapter) devices with a VoIP service. Softphones are basically software-based phones that enable you to have a full-fledged phone right on your computer. Available as web apps (where you log into the phone on a web browser window using a username/password combination), desktop apps (where the softphone is downloaded as an application on your computer or laptop), and mobile apps (where the softphone is downloaded as an application right onto your smartphone), softphones have the exact same functionality as a “hard” phone:

  • A keypad on your computer screen allows you to use your mouse to dial a telephone number.
  • Buttons are available to transfer a call, place a call on hold, mute a call, hang up a call, and otherwise manage a call as you would on a regular phone device.

The truly remarkable aspect of VoIP is the wide variety of advanced calling features that are made available to you by the overlap of your telephone system with your Internet connection, including:


As mentioned earlier, softphones allow you to make and receive calls without needing a telephone on your desk. In fact, you can equip your entire office with just softphones on computers and you’ll have a fully operational phone system for your business.

Video Conferencing

OnSIP's group video conference call in the web or desktop app.
Host a group video conference call straight from the OnSIP web or desktop app.

Instead of spending a ton of money on expensive video conference equipment, VoIP providers typically offer it as part of their service platform. With OnSIP, you can host group video conference calls directly in the OnSIP app, OnSIP’s own softphone. Whether you use the OnSIP web app or OnSIP desktop app, you can set up a video conference call right on your computer or laptop without needing any external devices—and if you use the web app, you won’t need any downloads or plug-ins, either.

Website Voice & Video Chat

OnSIP sayso as it appears on a business website.
OnSIP sayso appears as a floating button in the bottom corner of your business website.

While text chat and bots on business websites are all the rage now, OnSIP enables you to introduce a human, conversational element to site visitors who want to chat with your business. OnSIP sayso empowers your visitors to start a voice or video call—their choice—with one of your business representatives using only their web browser window. A customizable button in the corner of your website will invite visitors to start the call without having to pick up a phone, dial a number, navigate an automated menu, or even wait on hold.

Real-Time Call Queue Dashboard

Call queues are advanced calling features that hold callers in a line until a business representative is available to answer the call. This feature ensures that every person who calls your business speaks with a human being rather than gets sent to a voicemail box. Call queues also typically come with real-time dashboards that give supervisors a detailed overview of their queues.

OnSIP’s Enhanced Queue Dashboard is available in the web and desktop app, and it displays the real-time activity going on in the queue: how many callers are waiting on hold, the time that each caller has been waiting on hold, which of your reps are currently on calls, and much more. Supervisors can even listen in on live calls and barge into them should the rep need assistance in answering the caller’s questions.

VoIP vs Landline vs Cell: Bridging Vast Distances with Different Technologies

While the act of making a telephone call is just a simple sequence of events, there is so much more happening in the background to support it. Next time you make a call, just imagine what kind of pathway that the call has traveled in order to connect you and the person on the other end of the line!

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