Figure 1. Circle axis

So it’s a line that passes through the middle of the circle. A cylinder also has symmetry, and therefore also has an axis. Cylinders are important in this conversation because the cross section of the wire is in the shape of a cylinder. We try to show the axis of the cylinder in Figure 2.

Figure 2. Cylinder axis

Shapes and other objects also have symmetry, so they also have an axis with respect to this symmetry. But because of the increased pressure inside my bilaterally symmetrical brain, that’s all I’ll say about symmetry.

So the cable axis is the imaginary line that runs down the center of the cable length. Now, how do two connectors share the same cable in the coax? One of the conductors is called Center connectorgoes directly down the cable axis. The other connector is called External connector or shield, It is wrapped around an insulating material called a insulatorwhich spaced the shield at an equal distance from the central conductor. You can get an idea of ​​this arrangement from Figure 3. In cross section, you can think of the central conductor as a line, and the outer conductor as a circle, and they both share the same axis!

Figure 3. Coaxial cable structure

RG6 coaxial cable types

Aside from the typical differences between indoor and outdoor communications cables where the cable jacket itself determines the installation environment, coaxial cable comes in double shield (DS) and quad shield (QS) variants depending on EMI/RFI/ESD (electromagnetic/radio frequency interference and electrostatic discharge) existing. More intervention? Choose the quadrilateral shield. Do you have an outdoor installation that is likely to be subject to larger ESD events? Choose the RG6 Quad Armor. RG6 quad armor is nominally more expensive per foot than the double armor variant but is thicker and more difficult to finish. Weigh your options! Both options are shielded cable and the cable shield must be bonded to ground for optimal performance and equipment protection. For more information on the correct cable jacket for installation, please see Facts About Ethernet Cable Jacket Ratings. For a more detailed look at the differences between quad and dual shield coaxial cables, please see below The difference between Dual Shield and Quad Shield coaxial cable.

Coaxial cable applications and speed

Most often, coaxial cable is seen and referred to as coaxial internet. Coaxial cable is used for many applications:

Data (transfer of private data, usually not Ethernet packets)
Video applications
Audio transmission
Radio frequency antenna installations
Cable TV and HDTV
Satellite antenna installations
Broadband Internet

Although it can send Ethernet packets, RG6 coaxial The cable is very slow because it works with a single conductor circuit, reaching a maximum speed of 10 Mbps in peak coaxial use for LAN applications.

The 10BASE-T Ethernet standard made the switch to twisted pair cable in 1990. For your entertainment, a backward-compatible network card from that era is shown in Figure 4.

Figure 4. Network interface card with both coaxial and twisted pair connectors

Speed ​​needs have increased dramatically over time, making coaxial cable obsolete for Ethernet applications (not counting mixed use cases like MoCA). As such, coaxial cable is no longer used for the purposes of transmitting Ethernet data packets. For more information about MoCA hybrid formulations, please see MoCA vs Ethernet.

Enter the copper twisted pair category cable, a cable designed specifically for Ethernet data transmission!

Building Ethernet cables

Balanced twisted pair category cable is commonly referred to as “Ethernet cable” or “network cable.” How is it different from coaxial cable? In almost every way except that both usually contain copper. There is nothing in a twisted pair cable that shares a coax with anything else. In fact, the complete lack of symmetry in the cable It is what gives it its most important characteristics. It is made of four pairs of insulated conductors, the conductors of each pair twisted around each other (Figure 5, 6).

Figure 5. The four pairs of conductors in a balanced twisted pair cable

Figure 6. Cross section of a balanced twisted pair cable

Not only is each pair twisted, but each pair is twisted at a different rate (turns per inch). This way, the conductors inside the cable are rarely, if ever, oriented parallel to any other conductors inside or outside the cable. This allows the connectors to avoid noise and signal loss due to Electromagnetic interference (Amy).

More about this can be found on our website Cable Academy blog, Why are the wires inside an Ethernet cable twisted?

Ethernet cable applications and speed

Ethernet copper twisted pair category cable is used for an amazing range of applications such as:

LAN (Local Area Network) data transfer for computers, printers, servers, etc.
VoIP (Voice over IP)
PoE (Power over Ethernet) for data and power-to-power transfer and connectivity to signage, lighting, WiFi access points and security cameras
HDBASE-T (video-specific applications)

In addition to having four conductor circuits instead of a single coaxial conductor circuit, copper twisted pair Ethernet cable comes in different categories depending on your speed requirements. Currently accepted TIA categories are Cat3, Cat5e, Cat6, Cat6A, and Cat8. Cat7 also appears, but this is the ISO/IEC 11801 standard used outside North America and requires unusual termination devices such as GG45 and TERA connectors. Ethernet data packet transfer speeds over 40 Gbps copper twisted pair Ethernet for Cat7 and Cat8. That’s 4000 times faster than coaxial cable!

Like most important things within culture, twisted pair cable goes by many names. In addition to twisted pair cable, it is also called datacom cable, network cable, data center cable, enterprise cable, category cable, but most people just call it Ethernet cable.

Ethernet will be around for a long time to come, but like everything else we want to go faster. Learn more about How Ethernet cables compare to fiber optic cables here!

Frequently asked questions

Do you need a coaxial cable for the Internet?

This will depend on your Internet Service Provider (ISP). Many homes are still served with coaxial cable for broadband HDTV and Internet service, although fiber is making progress at an increasing rate.

What are the main types of coaxial cable?

There are many different types of coaxial cable. The old naming system is RGX (where X denotes the type of coaxial cable). The new designation is Series X (where X indicates the type of coaxial cable). The main types we see today are Series 59 (RG59), Series 6 (RG6), and Series 11 (RG11).

Is coaxial faster than ethernet?

Both coaxial cables and twisted copper “Ethernet” cables have their intended uses. For some purposes, an Ethernet cable is faster, and for other purposes a coaxial cable is faster. For local area network (LAN) data transfer using Ethernet adapters for packet-switched Ethernet networks, a copper-paired Ethernet cable is much faster. The fastest is fiber optic cable.

Are all coaxial cables the same?

On a basic level, yes, all coaxial cables are the same. There are two conductors that form one circuit. Differences are found in the amount of shielding, cable covering, conductive material, and thickness.

How does a coax compare to a fiber optic cable?

Both coaxial cables and fiber optic cables are used for data communications, but the similarities stop there. Coaxial cable uses metal conductors where as fiber optic cable uses glass conductors. Coaxial cable is always shielded for EMI/RFI/ESD where fiber optic cables do not need shielding (although fiber optic cables may be armored for durability, not to prevent EMI/RFI/ESD). Finally, fiber optic cable uses light to transmit data where coaxial cable uses low voltage electricity. Light travels much faster and can travel farther (or both).

Final thoughts

So, if all these different types of media are used to transmit signals over Ethernet networks, why is only balanced twisted pair cable called Ethernet cable? Because the vast majority of people only used twisted pair cables to connect to the network.

As we said above, the 10BASE-T Ethernet standard switched to twisted pair cabling in 1990. This happens to be the same year that the first web browser was created at CERN, a research institution in Switzerland. The World Wide Web became available to ordinary users in 1994 with the release of mosaic Browser, called later Netscape. Over the next two decades, Internet use exploded to include users from all over the world with virtually unlimited content. Almost all of these users are connected to their networks using twisted pair cable.

So why do I call Ethernet cable twisted pair? I think it’s because all my friends do it.

Happy communication!