The development of modern technologies gives significance to the question: what is WiFi? It says Wi-Fi. People usually answer without thinking: “Wi-Fi is the Internet.” In fact, it’s not at all like that. This question can be answered like this:
Wi-Fi is a wireless network protocol that provides reception and transmission of information between access points and clients. Communication is provided between one or more access points and at least one client, or between two or more clients. A Wi-Fi connection allows you to locally exchange information (data packets), or access the Internet - if you have a device.
In most cases, when people say “Wi-Fi,” they mean a wireless network that has become widespread, both paid and free, in offices, apartments, public institutions: cafes, restaurants, airports and other places. Of course, nowadays it is not always possible to find free Internet access, although in my city there are places where you can surf the Internet for free. 😉
The abbreviation Wi-Fi expands to "Wireless Fidelity" which literally translates as “wireless precision.” When coming up with the term, the developers used the association with “Hi-Fi” for advertising purposes, which translates as “high precision.”
The decoding: “high accuracy wireless data transmission” has become widespread at the suggestion of the developers. Today, this formulation has been abandoned for a number of reasons, and now “Wi-Fi” officially means nothing.
Minimum possible connection speed: 0.1 Mbit/s. The maximum possible real connection speed: up to 54 Mbit/s. The maximum possible theoretical connection speed: up to 600 Mbit/s. 
Connection of Wi-Fi-enabled devices is provided through standalone access points, either managed by access point controllers or managed without access point controllers.
Why has Wi-Fi become so popular?
What Wi-Fi is is now known. But why has it become so popular?
— Low cost of deployment. There is no need to lay cables and damage walls, which has special meaning in premises of historical value, or some obstructive architectural features. Often it is more profitable to expand an office network by installing points Wi-Fi access rather than ordering an additional gasket.
I have used Wi-Fi more than once to deploy a network in various organizations, and I think that's the biggest plus. To avoid making unnecessary holes in the walls, you can, for example, install a point in one office and connect another in the next. But it is also important to understand that when creating a network, you need to draw on paper or in a special program a diagram of how the computers are located, since it is possible that you will forget about some computer.
— Full access to the network. Both mobile/portable devices and personal computers can be connected into a single network without being tied to one specific location. I appreciate wi-fi for the opportunity to access the Internet while lying in my favorite chair/bed, in any comfortable position, without getting tangled in wires.
I had experience in servicing a company in which all computers worked via wi-fi. When moving the computer to another office, I did not need to go to the cross-room; there are no extra hemorrhoids for administrators. Of course, the question is brewing, what about printers and other devices? Everything is very simple, almost all Wi-Fi-enabled devices were purchased from this organization. Cool right? 😉 .
— Large quantity connections. For example, when you have Wi-Fi at home, you don’t need to think about how many computers can be connected to the Internet through your device. You can read about connecting WiFi to your home PC in the article: “”. If you have a laptop, then look.
- Lower radiation. According to observations, a device connected to the Internet via Wi-Fi emits ten times less than devices with a similar connection through a provider mobile network.
Now let's look at the advantages and disadvantages of WiFi.
What are the disadvantages of Wi-Fi?
What Wi-Fi is and where it can be, I explained a little higher. Now it’s worth talking about the disadvantages of WiFi.
— Significant transmission noise. The range used by Wi-Fi is also shared among alternative wireless connections such as Bluetooth and many others. Microwave ovens and other household electrical devices emit in the same range. Noticeable interference is created by walls and ceilings - all this results in a noticeable decrease in the actual data transfer speed.
If two walls (brick or concrete) separate your device (computer, laptop, etc.), then the device may lose point, and then your Internet will turn off from time to time. In this case, you need to test. One day a friend called me and complained about the Internet, saying that it constantly disappears and then cannot connect. When I came to him, I saw the following picture: there was a microwave oven, next to it stood home phone and there is a router (dot) near the phone, I just moved it 40-50 cm away from all devices and after that it didn’t call me about the Internet anymore.
— Very low information security. This is a weak spot in the network. It is not recommended to transmit valuable information over Wi-Fi without additional security guarantees.
Important! To connect to Wi-Fi, always create complex passwords that cannot be cracked using brute force methods. Regarding security, you can read the articles: “” and “”.
— The power supply for Wi-Fi may burn out. The cost of a power supply is approximately 20-30 percent of the cost of the router, or even more. 
Today, Wi-Fi technologies are limited local network with spot coating. However, development allows us to already start talking about the network as a possible alternative to mobile operators. Programs are already being implemented that can provide full coverage in some cities and even countries.
When I graduated from college, the director asked, as specialists, to cover public places in our city with Wi-Fi so that everyone could surf the Internet for free. While none of us have done this, I think very soon in big and small cities, it will be available to everyone. So far in our city there are only promises (since 2011), but it’s nice that in the near future I can go for a walk, in the park and sit on a bench and write another useful article for you.
Do you think this is real?) To write this article, I scoured the Internet in search of information that reveals the question, what is WiFi?, because on my blog in the future there will be articles related to Wi-Fi.
Some difficulties may arise when working with WiFi:
How to distribute the Internet via WI-FI from a laptop
In the early days after the advent of the Internet, everyone tried to hide huge amount wires PC users built them into baseboards, packaged them in special bags, fixed them to the walls, etc. Special holes were even made in the tables for network cables. However, after the advent of Wi-Fi wireless technology, everything has changed dramatically, and you no longer need to think about how to disguise the cords in the room.
General description
Conversations about what Wi-Fi means began at the end of the last century, when this technology was going through the testing stage. It began to become widespread around 2010.
When thinking about what the word Wi-Fi means, you should remember the English phrase “Wireless Fidelity?”, which translates as “wireless precision.” It is from this phrase that the abbreviation “Wi-Fi” itself comes from.
A Wi-Fi network is not the Internet. This is a special principle of information exchange between devices that have built-in radio modules. These devices today are found in almost all modern models of technology and electronic equipment. T So, at first, modules were built into only a few devices:
- smartphones;
- portable PCs;
- handhelds.
However, now printers, photo and video cameras, and even kitchen multicookers have wireless connectivity. And there are more and more tasks for which Wi-Fi is needed.
A mandatory component of Internet access via a Wi-Fi system is the so-called access point. A router is used for this purpose. This is a compact device with standard connectors and amplifier antennas. The device is connected to the network using a twisted pair cable, and antennas are designed to transmit information to devices connected “over the air”.
In addition to the router, access points can create:
These gadgets must have an Internet connection using a mobile network (sim card with 4 G, 3 G or the outdated GPRS). In this case, the principle of transmitting/receiving information will be similar to that of a wired router.
Technology functions
The main task of Wi-Fi technology is to visit resources on the Internet, download files and communicate online without being tied to wires. Today, an increasing number of access points are appearing in cities that anyone can use. Experts have no doubt that soon the Internet will be available in any locality.
Radio modules are also often used to set up an internal network, for example, in a company. Lenovo Corporation specialists, who know what Wi-Fi means, have long developed a special program for mobile devices, which makes it possible to very quickly exchange various files between devices using a Wi-Fi network without an Internet connection.
The application creates a special virtual tunnel that is responsible for data transfer. The advantage of this technology is that with its help information is transmitted several tens of times faster than using outdated Bluetooth. So, mobile phone Can be used as a gaming joystick for a laptop or console. You can also change channels on your Wi-Fi enabled TV.
Features of application
To get rid of an array of cables once and for all in your home or office, you need to get a router in advance. The device has a special socket, which is usually highlighted in white or yellow. You need to connect a network cable to it. Then you have to configure the equipment in accordance with the instructions. After this, on all devices that have a Wi-Fi module, you need to activate it, find the created network and connect to it.
It should be noted that the speed of Internet access depends on the number of devices connected to one access point. This is due to the fact that the speed will be proportionally divided between them.
If your PC does not have a Wi-Fi module, you can purchase it separately. By appearance This device resembles an ordinary USB flash drive. The average price of a device is about 10−15 dollars.
From a smartphone, you can access the network using the “Access Point” function. For this purpose, you need to configure the option in the settings of your tablet or mobile phone.
Wi-Fi makes it possible to access the Internet without any cables or wires. The signal source can be any device that has a radio module. The range of action depends on external obstacles in the form of walls, ceilings and other structures, as well as the power of the transmitting antenna. With this modern technology You can not only use the Internet, but also exchange files on different devices, as well as combine all gadgets into a single internal network.
The presence of Wi-Fi in various devices is no longer surprising. Manufacturers try to best meet the needs of potential buyers. However, not everyone uses the full technological potential of modern devices. Some don't need it, others just don't know how. Today we will look at where it came from, why it is needed and how to use Wi-Fi networks. The more we know, the better our life. Recommendations on how to use Wi-Fi may be useful to anyone who is taking their first steps in this direction.
Let's start from the beginning. Wi-Fi (pronounced wi-fi) is a way to transfer data without using a wired connection. Its second name is the IEEE 802.11 standard. The letters b/g/n mean Originally created for service cash register systems. Now it is widespread and widely used in offices, public places (cafes, train stations, libraries, airports), and in private homes for wireless Internet access. This is very brief.
Why is it needed? Most modern devices: computers, laptops, tablets, communicators, smartphones have a Wi-Fi module “on board”. Moreover, Wi-Fi is now being actively used in printers, cameras, video surveillance systems and other devices that require a reliable channel for transmitting data wirelessly. It's convenient.
Any information can be received/transmitted. The range of local networks depends on the transmitter power and the presence of interference in the signal path (walls, buildings, trees, terrain). A home access point provides an excellent signal level within any apartment. This makes it possible to get rid of wires and establish full-fledged work for several users at once.
How to use Wi-Fi?
This method of data transfer is now mainly used to access the Internet. A special device (router/router) creates a local network and “distributes” the Internet via a wireless protocol. Access to the local network can be free for everyone (insecure network), and protected with a password (secure network). You can connect to this network using the Wi-Fi module on your device. After connecting, you get full access to the Internet. Your access speed will depend on the speed of your incoming connection and the total number of connected devices.
Wi-Fi networks: how to use mobile device owners
Despite the “many books” in the previous paragraphs, everything looks simple and convenient for the user. Turn on Wi-Fi on your device (laptop, tablet, smartphone) and your gadget automatically detects all networks that are within reach. To connect, you need to select a network from the list. To connect to a secure network, you will need a password (ask the owner/administrator of the network); an unprotected network does not require a password.
How to use Wi-Fi in public places
It’s not for nothing that a network open to public use is called an insecure network. This means that other users can see the data you share. This point must be kept in focus if you enter passwords to access your accounts, payment documents, or simply do not want to let anyone into your personal life. This does not mean that everything you wrote, said or viewed will immediately become the property of attackers. But there is such a possibility.
How to use Wi-Fi at home
If you want to enjoy the benefits of progress at home, make sure that lovers of “freebies” do not use these benefits with you/instead of you. Be sure to password protect your network. Otherwise, anyone can easily connect to your home network, and you will have to pay for all the “uninvited guest” traffic out of your own pocket. Even if you have unlimited Internet access, you risk losing speed and giving access to your confidential information.
There is a saying: forewarned is forearmed. This, of course, is not a reason to become paranoid and see spies everywhere in the company of pests. One thing is clear: understanding the potential risks and taking minimal precautions will save you stress and money, and will also make you feel safe.
Last winter, specialists from Avast conducted an experiment on participants at Mobile World Congress. They created three open Wi-Fi points near the stand for registration of exhibition visitors at the airport and called them the standard names “Starbucks”, “MWC Free WiFi” and “Airport_Free_Wifi_AENA”. In 4 hours, 2000 people connected to them.
A report was made based on the results of the experiment. Specialists were able to analyze the traffic of all these people and find out what sites they visited. The study also allowed find out personal information 63% of participants: logins, passwords, email addresses, etc. And the victims would never have known that their data fell into the hands of someone else if the experts from Avast had not revealed their secret
Most of those who joined were tech-savvy people. After all, they came to an international IT exhibition. But for some reason they did not take any measures on self-defense while using public Wi-Fi.
Below you will find out what the risks of connecting to free Wi-Fi can be and how to protect yourself when using it. Let's start by listing the most common dangers.
Danger No. 1. Traffic analysis
The owner of a Wi-Fi point or the person who has gained access to it can view all the traffic that passes through it. And using a data packet analyzer (for example, Wireshark or CommView) to find out which pages people accessed from connected devices and what they entered into forms on sites that use the http protocol. This could be login information, texts of letters, messages on forums.
You can also use a traffic analyzer to steal a cookie with a session identifier, which can be used to log into some sites under the victim’s account.
In 2017, most sites use the secure https protocol, through which logins and passwords are transmitted in encrypted form. And they cannot be recognized in the manner described above. But this does not mean that they cannot be stolen using a Wi-Fi network.
Danger No. 2. “Fake” pages to steal passwords
When a person connects to Wi-Fi in a public place, he can be directed to a page to confirm his identity by phone number or authorization through social networks. The owner of the outlet can collect all data entered on these pages for personal use.
Also, a person who has access to managing the router can configure, for example, redirection from facebook.com to the website facebb00k.com, where a copy will be posted home page a popular social network designed to steal passwords.
Danger No. 3. Malware infection
In the same way, a person can be transferred not only to phishing sites, but also to pages for downloading Trojans and viruses, which can steal from the computer a lot of information valuable to the fraudster (passwords, documents). The result depends on how much the victim cares about the security of his computer.
Now let’s figure out what the likelihood of running into problems when using public Wi-Fi is.
Are there many Wi-Fi points in Russia that are susceptible to hacking?
The website 3wifi.stascorp.com has a database of Russian Wi-Fi points (more than 3 million) that have security problems. It is collected by members of the Antichat forum using RouterScan. This program scans available routers/routers, collects information about them and identifies weakly protected devices.
The full version of the database (with passwords and other useful information) is available only by invitation. But casual site visitors can look at the map (is your router there?) and get acquainted with the statistics.
Almost 200 thousand access points do not apply any protection. The same number use the outdated WEP encryption protocol. This means that you can easily guess the password for them in 5-10 minutes.
But even among those who have enabled modern WPA2 encryption on their routers (many router models do this automatically), there are tens of thousands of people who use the passwords “12345678” or something similar that was in the default settings.
Many people have WPS enabled - a mechanism for quickly setting up a router using a PIN code, which is also often a standard combination. And this makes it possible for “leftist” people to use their equipment.
Selecting a password for a Wi-Fi point
Even if a person replaces the standard router password/PIN code from WPS with “12345678” or “26031993”, this does not increase the degree of protection against cyber fraudsters. After all, such combinations can be found in a few hours or even faster if the password is very simple or is on the list of frequently used ones.
Creating fake access points
In the fall of 2015, after the terrorist attacks in Paris, someone created a copy of the “Mos_Metro_Free” access point in the Moscow metro. Some metro passengers connected to it instead of the main point and, instead of the standard advertising welcome page, saw a website with the logo of a terrorist organization banned in Russia.
Using programs freely available on the Internet (for example, the airbase-ng utility), you can create a copy of any access point. And if the “fake” signal is stronger than the original, then all devices that are configured to automatically connect to the original access point will connect to the “copy”. And on them it will be possible to perform all the actions described at the beginning of the article.
Stealing passwords from an access point using a copy of it
Fake access points can be used not only to deceive users, but also to steal router passwords. For example, using the Wifiphisher tool, which appeared a couple of years ago.
When the victim connects to the fake access point, he is redirected to the same fake “admin page”, where he is asked to enter the password for the router in order to download new firmware.
If the owner falls for it, then there will be no need to search :-)
What equipment is needed to “hack” Wi-Fi?
In the article about the dangers of free Wi-Fi, there are often pictures of a man with black tights on his head, a laptop and a huge antenna hiding under a table in a cafe. But in reality, this process is invisible to outsiders.
Kali Linux, a distribution with a pre-installed set of tools for attacking different systems(including Wi-Fi networks) can be installed on the simplest laptop and even on an Android smartphone. It even has a version of KaliNetHunter specially adapted for Google Nexus devices.
If you buy an external Wi-Fi adapter for your smartphone, you can use it to perform all the steps described above. And do it so that no one around you notices it.
There are also various applications for amateur Wi-Fi hacking for Android. For example, DroidSheep (in the second screen), DroidSniff, FaceNiff, etc. They can view the traffic of the network to which the phone is connected and steal session identifier cookies from poorly protected sites. About 5-6 years ago, using them you could even log into someone else’s VK account (now the security level is social networks got up a lot).
Or WPSConnect to check whether the point has one of the standard WPS PIN codes.
From what distance can you “hack” Wi-Fi?
Even if a Wi-Fi point is used in a closed room, to which only your own people have access, this does not mean that you can not think about its security.
The term wardriving appeared in the USA about 15 years ago. Roughly speaking, this is driving around the city in a car, inside of which is a laptop with special software and a powerful Wi-Fi antenna.
The goal of this activity is to look for potentially vulnerable access points in your city and “hack” them. The radius of the impact zone can reach several hundred meters. The exact value depends on the power of the scammers’ equipment and the density of the area.
There is another way to get to hard-to-reach Wi-Fi points.
Three years ago, researcher Gene Bransfield introduced WarKitteh (microcontroller (SparkCore) + WiFi module + battery + GPS module, see picture 2). This device can be attached to a cat or dog and allow the animal to wander into the area where you need to access Wi-Fi hotspots.
Cases of wardriving using drones have also been described.
How popular is the topic of Wi-Fi hacking?
The opportunity to use the Internet for free and view other people's traffic interests many people around the world. Hundreds of thousands, perhaps even millions, of articles have been written about various approaches to achieving these goals. It is possible that one of them is now being read by one of the residents of your house.
And he doesn’t need to have any unique skills to accomplish his plans. After all, Wi-Fi hacking is relative simple task, if the owner of the router did not think about security (disabled WPS, updated the firmware in time, came up with a strong password).
An anecdote on the topic: “The Internet stopped working. How to quietly hint to the irresponsible neighbors above that it’s already the first day?”
How to protect yourself when connecting to unknown Wi-Fi networks
Follow standard and well-known online safety rules:
1. Use a VPN to encrypt traffic. You can read more about this here
Some people think that Wi-Fi means free internet, but this is not entirely true. It is, of course, free, but it requires an access point.
Typically, this service is provided by cafes and supermarkets, and you can also install a router at home or via a computer if it is equipped with a Wi-Fi module.
Navigation
Wi-Fi option is available on many phone models. Let's take a closer look at the features of connection and use on some of them.
How to connect a Wi-Fi wireless network on a phone running the Android operating system
Before connecting to a wireless network, make sure that the Wi-Fi module is connected. Do the following:
- go to your phone settings
- select the Wi-Fi module in the "quick setup" section by clicking on it
- move the slider to the right
After a few seconds, a list of wireless networks that you can connect to will appear in this section below. If you see a diagram of a lock next to the wireless network icon, it means it is password protected.
At this stage, decide which network you want to connect your phone to:
- click on it
- after that, a small dialog box will appear on the smartphone display with the name of the network you have selected, information about the signal level, type of protection and a code password if it is protected
- if you know the password, then enter it in the special field with a blinking cursor
- In order not to make a mistake when entering your password, check the special box below “Show password”
This way you can see exactly what characters you are entering.
After entering the password, press the “Connect” button. The phone will inform you that you have successfully connected to the selected network.
Wi-Fi won't connect to phone
The first thing you need to do is make sure your device has the current date and time. If it is a smartphone and you removed the battery from it, then when you turn it on, the wrong date may be displayed. Because of this, it will not be possible to connect to Wi-Fi.
To solve this problem, set the correct date:
- open the “Settings” menu item
- find the item “System” section “Date and time”
- set the current date, time and save the settings
- connect to Wi-Fi
If after these manipulations the problem is not solved, then check the Wi-Fi password:
- Find in the settings the access point to which you cannot connect
- Hold your finger down until a window appears with “delete” and “edit” options.
- select “change network”
- in the “password” line, enter the Wi-Fi password, following all the rules of capital and small letters (if they are there)
- click “save”
- connect and check if your problem is solved
If you entered the password correctly, but there is no connection, use the special Wifi Fixer program. It can be downloaded completely free of charge on Google Play. Install the application and restart your smartphone.
Turn on this program and connect to the network. In the “KNOWN” section, the application will show those access points that are ready to connect. The Wifi Fixer program works in automatic mode, i.e. eliminates all problems that have arisen.
If the program did not cope with the task, scan your phone for viruses. To do this, launch the antivirus application that is installed on your smartphone (or install it from the Play Market).
Wi-Fi connection problems on Chinese smartphones
It often happens that when you enter the wrong password and try to connect to Wi-Fi, instead of a connection message, your phone will give you the message: “Saved, network type.” This will be followed by several authentication attempts and a connection error. To troubleshoot, do the following:
- call the dialog box by clicking on the selected network
- in this window, select “delete”
Don't worry! The network will not disappear anywhere. She will appear on this list again. After which you can repeat the operations performed by entering the password.
If you entered the correct password, but the phone displays an authentication error:
- turn off the Wi-Fi module and then turn it on
- try rebooting your phone
- connect to Wi-Fi
The problem may be in the router itself that distributes the wireless network. Try connecting to a different router.
If you can’t connect, then reset your smartphone to factory settings, after doing backup copy settings.
IMPORTANT! If you plan to use Wi-Fi, then in the phone settings, display the access point “with request”.
Incorrect operation of Wi-Fi and DNS server
There are cases when incorrect wireless operation Wi-Fi networks depends on the DNS server. For example, if you go to the Play Market and pictures do not load, games and applications do not download.
Typically modems are configured in such a way that they receive automatic DNS servers from the company's providers. It happens that servers do not work entirely correctly or are configured incorrectly. A universal way is to enter the public DNS server from Google:
- go to your phone settings
- Wi-Fi networks
- hold your connection
- in the window, select “change” or “Statistical IP” (for different phone models)
- enter DNS: 1 8.8.8.8
- enter DNS2: 8.8.4.4
Save and check application downloads.
Once you are connected to the Wi-Fi network, check your Internet access. Open your browser and use it!
Video: Hotspot