What are the main components of a Local Area Network (LAN)?

Before digging deeper in the Local Area Networks, let’s start from the basics. A Local Area Network Is a group of devices that share a common communication path to the Internet or are commonly connected to a server, within a certain location and distance, such as head office or commercial establishment. These devices can also share resources between themselves in the same LAN. The Local Area Network can serve in a small office with two or three people and in a large building with hundreds of people. In the past years Local Area Networks were utilizing the Ethernet and Wireless specifications. Only in the last couple of years the Local Area Networks introduced the utilization of fiber optic connections. Ethernet is a specification for physically connecting the whole network and devices together in the LAN with the help of copper cables and Wireless specification uses radio waves to connect the same devices to the LAN.

For a successful connection and proper functioning, the Local Area Network must be made of at least six vital components:

  • A network adapter- this is a network adapter, or most commonly known as a network card (Network Interface Controller- NIC), that has the task to convert data into electrical signals and vice-versa. Although today every computer has this network adapter integrated in the motherboard, in the early rise of computers this wasn’t the case and network cards had to be bought separately and fitted on the motherboard. The network access element of its job is called a MAC or Media Access Control, widely known also as a physical address of a device. The MAC represents the serial number of the network adapter. The wireless equivalent of the network card is called a Wireless Network Interface Controller.
  • A wired medium- In the era of the Ethernet, every wired network connection has the need of cables. The most commonly used cable in Local Area Networks is the RJ45 Ethernet Cable. Other than this, other cables that could be used in Local Area Networks are twin-axial, Shielded Twisted Pair, Multi-mode fibers (MMF) and Single-mode fibers (SMF) for optical connectivity. When it comes to Wireless networks there is no need of network cables as the wireless device transmits radio waves from its WNIC.
  • Cable connectors- Today the most widely used cable connector is the RJ45. At the moment every computer in the world by default has a RJ45 port.
  • Power Supply- Both wired and wireless Local Area Network have the need of power. This is needed because wired networks use the power to convert electrical signals into data and wireless networks use the current to convert data signals into radio waves.
  • Router/Switch- In wired networks, one computer can’t connect to multiple other computers without the help of some kind of splitter. To play the role of the splitter the switch was developed. The switch repeats the signals gotten from one computer and sends them through other ports which are connected to other computers with an Ethernet cable in the same Local Area Network. Routers are a more sophisticated devices that are used to forward data traffic out of the LAN and out on the Internet or to another LAN. Switches use MAC addresses to distinguish the devices connected to them and routers use IP addresses. There is no wireless switch developed however the wireless equivalent of a router is called a wireless router.
  • A network software- this software that is installed on every device has the capability to convert the data into a packet. Then the packet is sent to its destination with the help of a combination of the MAC address and IP address. This packet then travels around the Local Area Network through various switches and routers until it gets to the destination.

The Local Area Network has the task to keep the customers connected to the Internet and provide them with the bandwidth they need for a fast and stable connection. However, with the development of new technologies and applications and the spread of the Internet throughout the world, the need for high speed Internet over a long distance has become essential. The new technology used in Local Area Networks that provides high bandwidth over long distance Internet is the fiber optic solution. This solution utilizes the optical light and optical fiber to transmit the data from one to another device. The data is sent and received with the help of optical lasers integrated into an optical module, also called a transceiver, down an optical cable with one or a couple of optical strands inside. This cable is connected to another transceiver or networking device with capability to convert the optical light into data.

Even though the cost for deploying a fiber optic solution is much bigger, the advantages and gains in performance are enormous. The most obvious and key characteristic of fiber optic networks is the bandwidth they can provide. Even though, heavy copper connections compared to optical connections, grow and continue to be developed to provide longer distances, they are slowly but surely substituted with optical connections. With today’s technology fiber optic equipment can provide many times more bandwidth with ease and at the same time consuming less power than the standard copper connections. Another key difference is the possibility for higher port density than Ethernet cables. The amount of LC optical ports that can be aligned on a networking device is much bigger than the amount of RJ45 ports due to its bigger and bulkier size. When we include the MPO solution in this equation which can have even 12 lines in a small optical connector, the sky is the limit.  

For the optical connection in the Local Area Network to work at maximum performance we need an optical equipment. The key optical components are optical transceivers and optical cables:

  • The optical transceiver is a module with the task to convert electric input into optical light. This light with the help of optical lasers (chips) is then sent down the optical cable. These transceivers, depending on their Form-factor, can provide speeds of up to 100 GB/s at distances up to 160 kilometers. They are commonly installed in a networking device (a switch) and because they are hot-swappable, their installation is simple. Keep in mind that optical transceivers are very sensitive to dust and other particles so handling them with care is a must.
  • The optical transceivers send the optical data down an optical cable. In fiber optic networks the cables are divided into two segments: Multi-mode and Single-mode fiber cables. Multi-mode cables are used for short range fiber optic connections due to their bigger core and the distance depends on the type of the fiber itself, OM1, OM2, OM3 or OM4. Single-mode cables are used in a long range fiber optic connections due to their much tighter core.

Fiber optic networks offer much larger distance limit when compared to copper connections. Most commonly, with copper connections, a repeater or switch must be installed at regular intervals, around 100 meters, to amplify the signal so it doesn’t degrade too much. In a long run this comes out costly for the companies and it requires big effort for installation and maintenance. With fiber optic connections the transmission distance is much greater. A Single-mode cable has the capability to go up to 160 kilometers when combined with the correct equipment and 160 kilometers is enough for a direct connection from the primary server room where the core is located to the final destination. Another advantage for the fiber optic connections is their endurance. Even though various physical stress can damage them, they are very resilient to radio frequencies and magnetic interference. Fiber optics are not conductive and, unlike the copper connections, if a lightning strikes the cables won’t conduct the current to the device and damage it so there is no need for deploying a lightning protection. Finally, fiber optic cables are a lot lighter than copper cables making them easy for transportation and installation.

Today with the great bandwidth demand the companies are deciding to upgrade to fiber optic networks even though the initial cost is bigger. They are convinced that in the long run the fiber optic networks are the future of networking. And with the help of fiber media converters they can allow their existing copper network to communicate with the newly deployed fiber optic solution seamlessly.