Why Standard Telephone Lines Use Coaxial Cables: Plus Other Cables To Consider


Since its invention in the 20th century, coaxial cables are the most popular cable type at home and around the office. They are easy to use and expand, inexpensive, durable, have great resistance to EMI, and accommodate speeds of up to 10Mbps. Internet providers, cable operators, and telephone companies worldwide prefer to use them over any other cable type. In fact, standard telephone lines use coaxial cables because of their ease in transmitting signals across different devices. If you are in the telecommunication industry, you are lucky. Today, we dive deep into the relationship between coaxial cables and the telephone.

But first, let’s go back to history and see where it all started.

Table of Contents

standard telephone lines use coaxial cables

The Telephone Line Invention

At first, telephone companies used iron or steel in manufacturing single grounded wires in telephone lines. But, they were inherently noisy, a problem solved by the use of copper wires. Thomas Doolittle developed this process to increase tensile strength. Because of their strength, copper wires are easy to use as overhead wires, which is how they took over the telephone wire market.

By the 20th century, you could spot telephones in more homes, finally making the invention accessible to all. At last, it wasn’t a novelty item available to a couple of people. Today, there are different telephone line cables in the market. While we can’t cover the whole spectrum, let’s check out with a few.

Five Types of Telephone Cables in the Market

Five Types of Telephone Cables in the Market

1. standard telephone lines use coaxial cables–Twisted pair cables

Twisted pair cables usually have two conductors twisted together in a single circuit. The conductors are copper-based and generally color-coded. The standard diameter is around 0.4 to 0.8mm. They vary in the number of twisted cables on each wire.

Usually, a cable carrying current creates electromagnetic fields and may interfere with each other when they are close. However, in twisted-pair cables, the signals move in the opposite direction, so the magnetic fields occur at different ends canceling each other. This way, they don’t interfere with each other.

Telephone manufacturers usually prefer to have many cables twisted together because the more cables you have, the better the sound quality. This reduces the possibility of cross-talk and external noise interference. These cables are also incredibly cost-effective, which also makes them pretty popular. However, they have high attenuation and low bandwidth, which may not always work for everyone. Generally, there are two types of twisted-pair cables. These are:

Unshielded twisted pair or UTP

Commonly found in businesses and residential areas. The cables don’t rely on any physical shield to clock connectivity issues or reduce physical interference.

Shielded twisted pair or STP

As the name suggests, these twisted cables have foil jacket shields to block external interference. Big enterprises and high-end applications prefer to use these cables, especially when they need the cables exposed to environmental elements.

Shielded twisted pair or STP

2. Coaxial cables

Like twisted pair cables, coaxial cables are also pretty common around the house and in businesses. They have a single channel that’s an insulated woven shield of copper. The inner layer carries the signal, while the outer layer, called ‘ground,’ is where you find most pairs of coaxial cables. The ground is where most information transmission occurs, especially when the cable is long distance.

Standard telephone lines use coaxial cables and with good reason. First, they support greater cable length, which makes them perfect for long-distance wiring. Also, they offer better shielding from any cross talk and have transmission speeds of up to 10Mbps. This is ten times more than what a twisted pair cable can transmit. Because of their insulation, they are durable, which also makes them a bit expensive.

What makes them perfect for standard telephone line use also makes them perfect for high-speed communication such as the internet and cable TV. Although a bit pricey, they are easy to install and use.

Standard Telephone Lines Use Coaxial Cables

3. Standard Telephone Lines Use Coaxial Cables–Fiber optic cables

Fiber optic cables are technically the ‘new kid on the block’ where telephone cables are a concern. They have been in the market for a while before finding their way in telecommunication. Traditional cables use copper to transmit signals, but fiber optic cables use light instead of electricity.

They have a plastic-based protective tube that makes the cable resistant to any external interference. Because of this protection, fiber optic cables transmit data 26,000 times faster than twisted-pair cables. Out of the three cables, fiber optics are the most expensive and the fastest in transmission speed. They come in two types.

  • Single-mode fiber optic cables are small and only allow one mode of light to enter simultaneously, reducing the number of reflections. The data travels faster, but they have a low attenuation rate. Their most common use is as telephone lines and other telecommunication use.
  • Multimode fiber optic cable – they have a larger diameter and allow more data to pass through. Since there is more light passing through, the cables have a lower attenuation rate and reduced bandwidth. This limits their use to short distances such as telecom and security systems.

4. standard telephone lines use coaxial cables–Jelly-filled telephone cables

They typically have underground cables and are water-resistant. They use polythene materials for insulation and have petroleum jelly between conductors. Petroleum jelly moisture and water entry make the cables suitable for all weather conditions. Usually, telecommunication companies prefer to use them in rural or hilly areas because they have a high tolerance.

Standard Telephone Lines Use Coaxial Cables

5. standard telephone lines use coaxial cables–Ribbon cables

Multiplanar cables or ribbon cables are composed of small-grade cables placed parallel to each other. Because the cables are side by side, they form a single wide flat cable that looks like a ribbon. This is where they got their name. All the wires are insulated and allow simultaneous transmission of data which is a huge advantage.

Usually, the cable bringing the signal into the house may not be your standard coaxial cable. But, once the signal hits your home, coaxial cables take over and work their magic. They pick the signal and direct it to individual computers or networks, depending on where it’s needed. So, since standard telephone lines use coaxial cable, how do you interface a cable with a phone line?

Steps to connecting a coaxial cable with a phone line

  1. You need to locate your phone line and where it’s coming into the home. The most logical place to start your search is the lower levels, such as your basement and access room.
  2. Check for the DSL port on your router and plug in your phone on the place that says ‘internet.’ You must push it in until you hear a clicking sound. This is an indication that you plugged it incorrectly.
  3. On your DSL modem, check for the input, let and spot the one with a high-bandwidth splitter. Now, screw your coaxial cable from your RF connector straight to the input leg identified.
  4. Check your incoming phone line and electrical panel. Locate the coaxial cable, and screw each cable into the input leg with a high bandwidth.
  5. Now, plug the router on your AC power and check the front for a green light at the front. Obviously, a green light means a positive connection.
  6. If you have other networks or computers, you’d like to connect to, this is your chance. Screw the coaxial cable from the jack plates to the RF or broadband, and you are good to go.


Although there are tons of cables the telecommunication industry uses, coaxial cables are definitely the first choice. They are durable, affordable, and have enough speed. Above all, whichever cable you prefer to use, we are here to help you meet your needs. So, schedule a consultation, and let’s figure out what you need together.