Chapter 46 | Part 2 | More About LANs

Networks | Part 2 of 3

In Chapter 46 Getting Started on Networking we went through the basics of what it means for a computer to be networked, the advantages/disadvantages as well as different sizes that networks come in — recall LAN, MAN and WAN. We also saw a simple Home LAN example. Now we are going a bit deeper into Local Area Networks (LANs).

Let's start with three important characteristics that differentiate one LAN from another.

​Topology	​Protocol	​Media
​A network topology refers to the physical or logical arrangement of devices on a network. There are several different types of network topologies, including: Star topology: All devices are connected to a central hub or switch. Bus topology: All devices are connected to a single cable. Ring topology: Devices are connected in a circular arrangement, with each device connected to two others.	​Network protocols are a set of rules and standards that govern how data is transmitted and received over a network. Some common network protocols include: TCP/IP: The protocol used for internet communication. HTTP: The protocol used for web browsing. FTP: The protocol used for file transfer. Each protocol has its own purpose and set of rules, but they all work together to enable communication between devices on a network.	Network media refers to the physical medium used to transmit data over a network. There are two main types of network media: wired and wireless. Wired connections use physical cables to transmit data, while wireless connections use radio waves. Wired connections are generally faster and more reliable, but require physical cables to be installed. Wireless connections, on the other hand, are more convenient and flexible, but can be slower and less reliable, especially in areas with poor signal strength. Wired connections are generally more secure than wireless connections, as they are more difficult to hack or intercept.

Wireless LAN (WLAN)

Wireless LANs (WLANs) use high-frequency radio waves and often include an access point to the Internet. A WLAN allows users to move around the coverage area, often a home or small office, while maintaining a network connection. Every component that connects to a WLAN is considered a station and falls into one of two categories:

• Access Points Transmit and receive radio frequency signals with devices able to receive transmitted signals; they normally function as routers.
  

• Clients On the other hand, may include a variety of devices, such as desktop computers, workstations, laptop computers, IP phones and other cell phones and smartphone devices.

Let's upgrade our previous home network with some wireless capabilities.

What can we notice about this upgraded network?

1. We've swapped out our previous router and replaced it with a Wireless Router. This gives us wireless capabilities to have computers and devices connect wirelessly to our network

2. We've added some wireless devices; a tablet and a smartphone. Both these devices use their embedded transmitters to communicate back and forth with the wireless router using microwave transmission.

Comparing Wired to Wireless connections

​Wired	Wireless
​Advantages: Generally faster and more reliable. More secure, as they are more difficult to hack or intercept.	​Advantages: More convenient and flexible. No need for physical cables.
​Disadvantages: Require physical cables to be installed. Less flexible than wireless connections.	​Disadvantages: Slower and less reliable, especially in areas with poor signal strength. Less secure, as they are more vulnerable to hacking and interception.

How do we deal with low wireless connectivity?

Sometimes despite having a wireless router, some computers and devices on the network may not be getting enough bandwidth. We notice this when download speeds on the device are low, or streaming content stops to buffer. Enter the Repeater.

Repeaters

Repeaters amplify or regenerate an incoming signal before retransmitting it. They are incorporated in networks to expand its coverage area. They are also known as signal boosters.

When an electrical signal is transmitted via a channel, it gets attenuated depending upon the nature of the channel or the technology. This poses a limitation upon the length of the LAN or coverage area of cellular networks. This problem is alleviated by installing repeaters at certain intervals.

But what if we needed to connect more wired computers to our router? Doesn't it have a limit on how many LAN wires it can support?

Yes! In these cases we may need to change our network topography to allow for more wired devices. This is where other pieces of networking hardware come in — hubs/switches.

Let's upgrade our network once more!

What changes can we notice?

1. We've added two more wired devices; a desktop and a printer. We've used a hub or switch as an intermediary to the wireless router.
   

2. We've grouped up our previous three desktops to another hub or switch.
   

3. Our wireless router now has three incoming wired connections...

   1. One from the cluster of three original desktops.

   2. One from the cluster of desktop and printer (with print server).

   3. One from the modem, providing internet service.
      

4. We've added another wireless device; a gaming console. Wireless routers can support many wireless connections, so it is easier to add more wireless devices.
   

5. Our printer has a print server used to translate instructions from the network to ones the printer can understand. In most modern printers, the print server is embedded and no longer a separate device.

Wireless and IoT

The Internet of Things (IoT) refers to a network of physical devices, vehicles, home appliances, and other items embedded with electronics, software, sensors, and connectivity, which enables these objects to connect and exchange data. IoT devices typically connect to the internet wirelessly, using technologies like Wi-Fi, Bluetooth, or cellular networks. Some common IoT devices include smart thermostats, security cameras, and fitness trackers. We mentioned IoT in Chapter 39 - Dedicated Computer Systems

But how do all these devices keep track of who is who? With so many computers and devices working on these networks, it becomes important for everything on the network to be uniquely identified. This question will be tackled in the next and final part when we go over addressing.

Quiz

1. Which device would I use if I had 5 computers but only had 3 ports available on my router? Use a Switch to connect some computers, and run a single wire from the Switch to one port on the router.
   

2. What type of transmission does Wireless LAN use? Microwave transmission.
   

3. What are some examples of home devices (shared resources) that could be used by multiple computers/devices on the networks? Printers, scanners, media centres and network drives.
   

4. If my computer is connected to my home WIFI but getting a very weak connection. What can I do to my network to improve this? Either connect the computer using a wire to a switch if one is close, or install a repeater to boost the wireless signal to and from the router.
   

5. What are some advantages of using a wireless connection over a wired connection? Wireless connections provide more flexibility and mobility since you can connect to the network from anywhere within range. They also don't require any physical cables, which can make them easier to set up and use.
   

6. What are some examples of IoT devices? Some examples of IoT devices include smart home devices (such as thermostats and door locks), wearable devices (such as fitness trackers and smartwatches), and industrial devices (such as sensors and controllers used in manufacturing and agriculture).

Continue to Part 3 - Addressing and Networking Devices