WiFi  

 

 

 

Overall Network Architecture

Most common way of using WLAN would be like as follows. In most case, the main communication line would be wired line and we connect AP(Access Point) to the wired backbone as shown below. Access Point is a device that communicate with the client device (e.g, Laptop or Smart phone) and convey the data through the wireline backbone. Access point has two different interface with it, one for connecting to wired backbone using wireline protocol and the other one for communicating to various mobile device using a wireless protocol.

When we say WLAN in terms of technology, it usually mean the technology being used to connect the mobile clients and Access Points in wireless communication method. The pages I will post will also be about those wireless communication technology between the mobile clients and an access point.

A WLAN (Wireless Local Area Network) is basically a setup that lets you connect your devices, like laptops, phones, or tablets, to the internet without using any cables. The main parts of a WLAN are the Access Points (APs), the wireless devices, and the wired backbone.

when you connect your device to the Wi-Fi, it talks to the APs, which then send your data through the wired backbone to wherever it needs to go. This setup lets you use the internet and share data without any cables, which is pretty convenient.

Access Points (APs) are like the middleman between your wireless devices and the wired network. They create a Wi-Fi signal so you can connect your devices to the internet. When you have a big space to cover, you might need multiple APs to make sure you get good coverage everywhere.

Wireless devices are what you use to connect to the Wi-Fi, like your phone, laptop, or tablet. They have a wireless adapter that lets them talk to the APs using Wi-Fi signals.

The wired backbone is what connects all the APs and other network stuff, like switches or routers. It's kind of like the backbone of the whole system, making sure that data gets where it needs to go. It uses Ethernet cables to link everything together, and sometimes even fiber-optic cables for faster speeds and longer distances.

Protocol Stack

As the terminology implies, WLAN is also a kind of LAN (Local Area Network), so it use most part of the standard LAN protocol especially in higher layer. The only difference is very low layer parts (PHY and Low MAC). Most of the contents I will deal with will be about PHY/MAC part of the protocol stack.

Let's break it down in a more casual way, focusing on the Wi-Fi protocol stack and the three main layers: Physical (PHY), Media Access Control (MAC), and Internet Protocol (IP).

Physical (PHY) Layer

The PHY layer is like the radio station of Wi-Fi. It takes care of turning your data into radio signals that can be sent through the air. Different Wi-Fi versions (like 802.11a, b, g, n, ac, and ax) use different methods and radio frequencies to send data at different speeds and distances. It also has some tricks to detect and fix errors that might happen during transmission.

Media Access Control (MAC) Layer

The MAC layer is like a traffic cop, making sure all the devices using Wi-Fi play nicely together. Since everyone shares the same airwaves, the MAC layer uses a system called CSMA/CA to help devices figure out when it's their turn to talk. It's also in charge of things like addressing, so data gets to the right place, and breaking big chunks of data into smaller pieces when needed.

Internet Protocol (IP) Layer

The IP layer isn't part of Wi-Fi itself, but it's super important for making everything work together. It's like the GPS for your data, giving every device an address and helping your info find its way from one place to another, even if it has to go through different networks. There are a couple of different versions of IP, like IPv4 and IPv6, that help with this.

So, in a nutshell, the Wi-Fi protocol stack has the PHY layer taking care of radio signals, the MAC layer helping devices share the airwaves, and the IP layer guiding your data to where it needs to go. Together, they make sure you can connect to Wi-Fi and surf the web without a hitch.

Security

Security is all about keeping your Wi-Fi network safe from hackers and nosy neighbors. There are different ways to protect your network, like using passwords and encryption. WPA2 and WPA3 are the best options for keeping your Wi-Fi secure and your data safe.

NOTE : Further details of WiFi Security is explained in a separate note here.

Network Management

Managing a Wi-Fi network means making sure everything runs smoothly. You need to plan the network, set it up, keep an eye on how it's doing, fix problems, and make it better over time. There are tools and software that help network admins do all this stuff.

Quality of Service (QoS)

QoS is about making sure the important stuff on your network gets priority. For example, if you're streaming a movie or making a video call, you don't want it to be slow or choppy because someone else is downloading a huge file. QoS helps to keep everything running smoothly by giving priority to the important stuff.

Roaming

Roaming is what happens when you move around with your device and it automatically switches to the best Wi-Fi signal. It's super useful in big places, like offices or campuses, where there are lots of different Wi-Fi access points. Roaming makes sure you stay connected without any hiccups.

Range and Coverage

Range and coverage are about how far your Wi-Fi signal goes and how well it covers the area. Lots of things can affect this, like how powerful the access point is, what kind of antennas it has, and even the building materials in the walls. Sometimes, to get better coverage, you can use things like mesh networks, which help extend the Wi-Fi signal without needing more wires.

Basic Features

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