What are the Different Types of Telephone Systems?

Mary Elizabeth
Mary Elizabeth

There are different types of telephones and corresponding types of telephone systems. The three main types are Plain Old Telephone Service, cellular phones, and Internet Protocol phones.

An assortment of cellular phones.
An assortment of cellular phones.

Landline telephone systems are part of the Plain Old Telephone Service (POTS), the analog service with copper wiring that is the direct descendant of the original telephone system courtesy of Alexander Graham Bell. The advantages of this system include standardized equipment, predictable sound quality, and — due to direct connections to the central office of the company — no need to share the system’s capacity with others. Because switches are in place, creating a private circuit for each phone call, it is also called the Public Switched Telephone Network (PSTN).

Cordless telephones connected to a landline are part of the Plain Old Telephone Service.
Cordless telephones connected to a landline are part of the Plain Old Telephone Service.

Another system is for cellular phones, with individual companies having their own networks with varying technology. Like POTS systems, cellular telephone systems are full-duplex systems, meaning that both people on the call can talk at the same time, but cell phones use radio frequencies, rather than copper wire. Though cellular networks began as mobile voice networks only, they now carry both voice and data. Some networks are national, while others are international, and new technologies are continually in development. The networks known as 3G support not only cell phones, but also netbook computers, smartphones, and wireless modem aircards.

An analog telephone adaptor.
An analog telephone adaptor.

Internet Protocol (IP), also called Voice over Internet Protocol (VoIP), another type of telephone system that is in use in the 21st century. This service piggy-backs on existing Internet connections, either cable service or DSL broadband. A device called an Analog Telephone Adaptor is the go between that connects whatever phone a person happens to have with either the broadband modem or the router.

Rotary telephones were dialed manually.
Rotary telephones were dialed manually.

IP systems can be set up with a single line for both Internet and telephone service, which can save money. With an Integrated T1 line, instead of being set up for voice or data, the T1 line is able to handle both. With Dynamic T1, the line is capable of assigning bandwidth as needed, given the current use.

3G supports not only cell phones, but also netbook computers, smartphones, and aircards.
3G supports not only cell phones, but also netbook computers, smartphones, and aircards.
Mary Elizabeth
Mary Elizabeth

Mary Elizabeth is passionate about reading, writing, and research, and has a penchant for correcting misinformation on the Internet. In addition to contributing articles to EasyTechJunkie about art, literature, and music, Mary Elizabeth is a teacher, composer, and author. She has a B.A. from the University of Chicago’s writing program and an M.A. from the University of Vermont, and she has written books, study guides, and teacher materials on language and literature, as well as music composition content for Sibelius Software.

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Discussion Comments


Thanks for this great post! The technology has really brought about many changes, but most of them I think are great, especially for business operators.


One of the worst jobs I ever had was operating a PBX telephone system! I was working in a large store, in sales, but for some reason the department manager figured I could stand in for the switchboard operator.

They did give me a very brief training session, then I was let loose on the phones. It was a nightmare, with lines flashing, people to connect to others, messages to be taken. I messed up big time when I cut off a call between the managing director and someone important, three times!


@MissMuffet - I agree the VoIP option would be an advantage to you, but there are several reasons why it is impractical, except perhaps as a small business telephone system.

The basic needs of a company requires things like transferring calls, call waiting, several lines available to call and so on. One line in just isn't going to be attractive.

Another issue is that VoIP services generally don't allow for emergency calls to be made. This may not matter in many cases, but it could be important to some people.

Two more potential problems are quality and security. With VoIP calls it's much harder to guarantee a clear and crisp connection. Add to that concerns about eavesdroppers and hackers and you can see why it scares people off.

Perhaps as technology advances some of these issues will be addressed. Until then I think you're unlikely to find many businesses wanting to switch over from their commercial telephone systems.


@everetra - Yes, the industry is plugging into the cell phone standard. Panasonic telephone systems are taking a lead here, if their press is to be believed. They provide headsets that link directly to cell phone systems. The headsets can be stationed around your home just as if they were regular cordless phones.

You use them to call through your cell phone without actually having the cell phone on hand at all times. It’s like turning your cell phone into a phone server to send and receive calls.


@Charred - You know we’ve come a long way with telephone systems when people and the industry refer to POTS services as “landlines.” That basically means that cell phones have dominated the mass market to the point where they have become the new standard, whereas landlines are an anachronism to the days of Alexander Graham Bell.

There are many households nowadays that don’t even have landlines; they use cell phones for their entire communications needs because of their mobility and affordability.


When VOIP technology was first vying for mass appeal, its first target was small business. PBX telephone systems nowadays almost exclusively use VOIP.

We use VOIP at work for our internal phone systems, and for good reason; it’s extremely cheap, and since the business-to-business calls (in this case in house) are as local as you can get, we experience no delay or any of the other problems associated with VOIP in the past. The big telecoms now are pushing VOIP for businesses more than they do for residential, for these very reasons.


I'd be lost without a VoIP system, which gives me free calls to others using it. I wish that more business telephone systems would add this program though. I know I can make cheaper calls to them using credit, but it would be even better if it was totally free!


I've been puzzling over the meaning of 3G for a while, after I saw it referred to in a computer ad. Thanks for the clear explanation of it in context.

The major changes that have taken place in the field of telephones is pretty amazing really. I can hardly imagine how people managed without cell phones.

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