What is Wifi: Definition and 66 Discussions

Wi-Fi () is a family of wireless network protocols, based on the IEEE 802.11 family of standards, which are commonly used for local area networking of devices and Internet access, allowing nearby digital devices to exchange data by radio waves. These are the most widely used computer networks in the world, used globally in home and small office networks to link desktop and laptop computers, tablet computers, smartphones, smart TVs, printers, and smart speakers together and to a wireless router to connect them to the Internet, and in wireless access points in public places like coffee shops, hotels, libraries and airports to provide the public Internet access for mobile devices.
Wi‑Fi is a trademark of the non-profit Wi-Fi Alliance, which restricts the use of the term Wi-Fi Certified to products that successfully complete interoperability certification testing. As of 2017, the Wi-Fi Alliance consisted of more than 800 companies from around the world. As of 2019, over 3.05 billion Wi-Fi enabled devices are shipped globally each year.Wi-Fi uses multiple parts of the IEEE 802 protocol family and is designed to interwork seamlessly with its wired sibling Ethernet. Compatible devices can network through wireless access points to each other as well as to wired devices and the Internet. The different versions of Wi-Fi are specified by various IEEE 802.11 protocol standards, with the different radio technologies determining radio bands, and the maximum ranges, and speeds that may be achieved. Wi-Fi most commonly uses the 2.4 gigahertz (120 mm) UHF and 5 gigahertz (60 mm) SHF radio bands; these bands are subdivided into multiple channels. Channels can be shared between networks but only one transmitter can locally transmit on a channel at any moment in time.
Wi-Fi's wavebands have relatively high absorption and work best for line-of-sight use. Many common obstructions such as walls, pillars, home appliances, etc. may greatly reduce range, but this also helps minimize interference between different networks in crowded environments. An access point (or hotspot) often has a range of about 20 metres (66 feet) indoors while some modern access points claim up to a 150-metre (490-foot) range outdoors. Hotspot coverage can be as small as a single room with walls that block radio waves, or as large as many square kilometres (miles) using many overlapping access points with roaming permitted between them. Over time the speed and spectral efficiency of Wi-Fi have increased. As of 2019, at close range, some versions of Wi-Fi, running on suitable hardware, can achieve speeds of over 1 Gbit/s (gigabit per second).

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  1. F

    Why does my device periodically disconnect from wifi?

    Hello, I have a wifi device that has been connecting with no issues to my local wifi: it first detected the local wifi and I then used the password to complete the connection.... However, one day recently, the device disconnected from the wifi. After some reading, it seems that either low wifi...
  2. S

    [ Raspberry Pi or Android ] --> WiFi Router --> USB printer

    A couple of years ago, I connected a USB printer to the USB socket on my broadband router. After a lot of trial and error (of which I remember no details) I was able to print from my windows laptop. Here are the port settings that currently work from the laptop: 1) Based on the above...
  3. A

    WiFi signal strength in Tunnels & Subways.

    As we see the WiFi signal strength is very low as observed in Tunnels, Subways & Undergrounds while we travel in a train or walk. We do not get the wireless network. Can there be any technical solutions for increasing the Wireless signal strength in these areas? Can this be considered a...
  4. Wrichik Basu

    Changing proxy server for WiFi in Amazon Echo Dot and Fire TV Stick

    One of my relatives has an Amazon Echo Dot and a Fire TV Stick. Both are connected to the same WiFi. Recently, their internet provider changed the proxy settings such that the default proxy no longer works. They have provided a set of proxies that can be used instead. We have manually set those...
  5. Wrichik Basu

    Configuring WiFi router with PPPoE and static IP

    Before I start, I must say that I haven't yet bought the Wi-Fi router. We have a broadband connection (no modem, just an RJ45 cable directly into the PC). I want to buy this Wi-Fi router and use the broadband connection to power it. Our ISP provides us a static IP, as well as a username and a...
  6. jack action

    Losing Wifi hotspot when connecting to signal

    New to Wifi. I bought the following wifi network adapter to make my PC a hotspot for my new smart phone to connect to: I could finally make it work by installing the driver from kelebek333 (from the PPA repo). I created a wifi connection with a method similar to this one. (The IPv4 & IPv6...
  7. J

    B Will Metal Obstruction Affect WIFI Reception of My Sonos One Speaker?

    Hi! I’m doing a little mod/add-on to my Sonos One wireless speaker (don’t ask what and why, long story 😅). My question is, how do you think this construction may affect WIFI-reception? I’ve marked the places where I think the antennas are, do you think the metal wire may interfere in some way...
  8. J

    Can you add a wifi module to a Samsung S8?

    My Samsung S8 has a weird problem. The wifi is not working. After bringing it to official Samsung Service Center. They tried fixing the firmware and software. But it didn't fix it. They said they couldn't fix the wifi module because it is inside the motherboard so have to replace the entire...
  9. F

    Wireless Router, WiFi, and a laser cutter

    Hello, I have a laser cutter which can connect to a wireless router via an ethernet cable. My laptop accesses the internet through the wifi provided in the office (I don't have access to a broadband modem). Is it possible to simultaneously be connected to the internet, via wifi, and at the...
  10. M

    Troubleshooting Ubuntu: How Do I Connect to WiFi on My Computer?

    Hi PF! Today my computer randomly didn't connect to wifi. So I restarted the machine, then still unable to connect, I asked my wifi to forget the network. Now when I try connecting to it, it asks for a username and password. At the bottom there is a "connect" button I could toggle, but it is...
  11. Wrichik Basu

    Is a VPN required for a WiFi hotspot meant only for a home?

    As discussed in this thread, I could convert my desktop PC to a WiFi hotspot, and it is working fine, with a more-or-less good range and a good speed. Connectify, the software that I am using, is advising me to install a VPN and is advertising their own VPN software (which, by the way, goes by...
  12. J

    Electrical WIFI 120 volt AC run on 12 volt DC

    I am getting one of those $10 WIFI units from china runs on 120 volt AC and I want it to run off of 12 volt DC car battery I am thinking will need to open up unit and try to figure out what the DC voltage is that is coming from the AC supply unit and then insert a fixed regulator of 12 or 5...
  13. ChrisXenon

    B Do multiple WiFi devices create areas of high EMR?

    I'm thinking in a typical house or office, areas of constructive interference may exist which aggregate the fields of maybe 10 WiFi devices. Wouldn't this mean the safe power levels stipulated for any single device would be routinely be exceeded? And if so, do we care?
  14. Wrichik Basu

    Turning a desktop PC into a WiFi hotspot using Connectify software

    I was reading online that Connectify can be used to convert any desktop or laptop PC into a hotspot. Our PC is fitted with Windows 7 Pro, 32-bit. It doesn't have an inbuilt WiFi adapter, and connects to the Internet using Ethernet. I wanted to make a hotspot using this desktop. There are...
  15. Tone L

    Which Wifi Hotspots Work Best in the Pacific Northwest?

    Hi all, I am planning a trip where I will travel to the pacific western United States. The states encompassing the trip are Idaho, Oregon, Washington and northern California. I want to upload some data along the way. I have been seeing many maps that outline hot spot coverage with companies...
  16. B

    How to build a Faraday cage to keep a WiFi signal inside?

    I'm working on a wifi device testing box and made the first prototype of the Faraday cage. I need holes because of cooling. For this reason, the box has 3mm diameter holes on the top. The box made from steel, and have 2mm wall thickness. The wavelength around 12,5 cm for 2,4 GHz and 6 cm for...
  17. Shaw-krow

    Long distance broadcast, internet data packets across town?

    I got something i want to do for fun and help out a...person i know but i never finished high school so that's my degree level. i was wondering if there is a way under $100 to possibly use my internet or posibly 2 peoples internet connections on the other side of the town i live in, split up the...
  18. S

    Electrical Can ESP8266 Send Data Over Long Distances Using Wifi?

    Hey guys. I am building a system for me and a few hundred people. We are incorporating the ESP8266 module to send data over the internet. Each house, however, has its own wifi. Does anyone have any solutions to this problem? I was thinking of setting up an access point and somehow sending data...
  19. S

    Using The ESP8266 Wifi Module Mini

    Hey guys, quick question on this module.The manual states " 5V-3.3 converter onboard for operation from USB" Does this mean that i can power the board straight from my computer without error from "overloading" the board.i ask this because a lot of other modules such as these don't work like...
  20. S

    Effortlessly Send Data via Motion Sensors with WIFI Technology

    Does anyone know how i can send information to the web through motion sensors?
  21. W

    Accessing Wifi Service with Specific Provider?

    Hi, Sorry if this is too simple. I was given permission by an employee to access to the Wifi service, using my PC, at a FedEx store,i.e., I will not be using their computers. I thought this would be straightforward: I would be given the key/password and then just log on to the network. But then...
  22. Y

    My old laptop fails to connect to the wifi

    Hi While I am working with Norton to fix my other computer, I have to pull out my old laptop to use at the mean time. It fails to connect to my wifi. It was working before two years ago, now it's not working. I open the troubleshoot and it detected that "Windows can't communicate with the...
  23. kyphysics

    How Safe is Free WiFi at Starbucks and Buffalo Wild Wings?

    Would you ever use their free WiFi on your cell phone? Wondering how safe it is and whether any precautions should be taken if I were to use it. Anyone ever been hacked/compromised in some way using free WiFi at a place like that?
  24. ilyasse

    Differences Between Radios & Antennas for CCNA

    hello people . i don't know if this is the right place to ask , but I'm studding for my cisco ccna and now I'm learning more about radio waves and wifi networks and i fall in love with the subject , what i don't understand is what's the difference between a radio and a antenna , because i asked...
  25. hackhard

    Tweeting Images with Arduino: Libraries and Limitations

    i ve got an Arduino Uno R3 and the OV7670 camera module SD Module and a Wifi shield . ive done tweeting with arduino using twitter library http://playground.arduino.cc/Code/TwitterLibrary i was wondering Is there any library to post images in a tweet? or some other hack?
  26. R

    Constructing a graph of WiFi strength

    I have way too much time to spare, so I came up with this fun little project. What i want to do is use my phone or laptop to incrementally collect data on WiFi strength at my location at that time, using GPS (longitude and latitude), and once I have enough data, (I'm fine if it takes like...
  27. F

    Does unconnected WIFI help pinpoint your location and why?

    I use waze and/or googlemaps to navigate. When I plan a route I 1st turn GPS on on my phone. Phone then always asks me to also turn on WIFI, but I always ignore this and leave it off because I thought its pointless if you're not actually connected to wifi. But does WIFI being on (without being...
  28. A

    Sending a Number Over Wifi: Energy Requirements

    I'm currently working on a project involving Wifi transmission. The device needs to send a 1-3 digit number to a computer/phone that is 5-15 feet away. Approximately how much energy will this take to send one number? Thank you! Austin
  29. M

    Locate & Disable Wifi Transceiver on Modem Circuit Board

    Does anyone know how to locate the wifi transmitter on a modem circuit board, is it the "Radio Transceiver"? Once located, is it possible to remove it or disable it. Wifi is enabled on my modem, and disabling it via software doesn't work.
  30. Geek007

    Does Microwave support only Line of sight communication LOS?

    Hi there, Wifi uses either 2.5 GHZ band or 5 Ghz band and these bands lie in Microwave in EM spectrum. As i read in books, Microwaves are propagated using line of sight (LOS) technique, so sending and receiving antennas should need to be aligned accordingly. But WiFi signals are broadcasted...
  31. D

    Faraday Cage not blocking wifi

    In our school we made a submarine. The inner hull is a few cm thick metal, so it should be a good farady cage, but it does not act like one when blocking wifi from inside the hull. Wifi antenna is not touching the hull. The hull acts like a faraday cage when blocking a phone signal from the...
  32. N

    Howto set Microsoft Virtual Wifi Miniport Adapter as default

    Dear Group, I just set up a Microsoft Virtual Wifi Miniport Adapter using administration command prompt, its function as wifi hot spot, so the other devices could use this hot spot for the internet. ( ) But whenever I shutdown the computer and turn it on, I can not find it, I have to...
  33. R

    Is 0.97 Mbps a slow wifi connection speed?

    How to check wifi's connection download or upload speed? is there some ip address or something else?
  34. R

    Is there a way to tether mobile's wifi to laptop

    I've seen the vice-versa of it by using a hotspot but when use on mobile it asks for mobile data. Why can't it only share the wifi?
  35. Tyatyra

    Is Living Next to a Wifi Antenna Dangerous? Exploring the Risks and Realities

    berkeman, I read a post of yours stating that "the house next door a wifi cell tower was more dangerous than the one with the antenna on top" Would you please elaborate? Is this because of the umbrella effect? I am considering buying a home which is next door to a house that installed a wifi...
  36. K

    ISP - Wireless broadband - necessary equipments

    Hi fellas! I am planning to start a ISP in our region, which uses cellular tower for bandwidth signal receiving & transmitting. We have established the leased line back bone to our network and figured out microwave & GSM antenna concepts to receive signals from suppliers and to send signals to...
  37. J

    Why isn't my Faraday Cage blocking wifi signals?

    So I made this Faraday Cage to block wifi in all directions but 1, to block it from my neighbor. Each side has 6 Layers of aluminum foil on it with no gaps, It looks sloppy because when I tried it and it didn't work I quickly added more trying to make it work. If I put my router inside this...
  38. Adrian B

    Battery for power -- cable modem and wifi router during outage

    Let me start by saying that the point of this question is to figure out if I can do this with items on hand instead of buying a UPS. I have a cable modem and wireless router which require 12V 750mA and 12V 1000mA respectively. In the event of a power outage, I'd like to be able to manually...
  39. F

    RF Workings of a Wifi Receiver

    I am curious to know how the RF front end of a Wifi receiver works. From my understanding, most RF receivers have to use networks of various oscillators, mixers, and filters to select a given frequency and remain insensitive to undesired signals at different frequencies, and I suspect that WiFi...
  40. Natanijel

    WiFi Signal Strength and Computer Orientation

    Hello everybody :) This is my first post! I have a mystery about radio communication that I was wondering about for a long time: If I have understood correctly, most computers have a single WiFi antenna in the shape of a rod, which is placed in a particular orientation. My question is this...
  41. M

    How can i stream my console to my computer using just wifi

    Is there a program i can use or do i have to create one? If so,is it even possible?
  42. K

    Induced EMF in house-hold WIFI

    Hi everybody, I was wondering how much induced EMF would be produced in a 20cm diameter coil with 100 loops produce. Has anyone conducted such an experiment? I am interested in quantitative values of the experiment. Thanks, KB
  43. S

    Sending signals from laptop wifi adapter?

    From what I understand, laptops have a wireless adapter that sends radio signals at a specific frequency to connect to a wifi router. My guess is that the wireless adapter is some sort of radio wave emitter/reciever, and could in theory be used for any other purpose besides connecting to a...
  44. M

    What Are My Options for Extending Wifi Range Away from Campus?

    I'm 6 blocks away from campus & probably 4 blocks out of range. I'm a student at the university so I do have the security code. I'm only 1st year EE, so I'm looking for advice. I can follow a schematic, but lack theory of operation that many of you have. Options?
  45. J

    Is it possible to use an iPhone as a wifi host for another network?

    My laptop doesn't like public wifi for some reason but iphone has no problem connecting. Is there anyway to have my iphone become a hotspot with another wifi instead of 3g or 4g?
  46. JimiJams

    Microwave ovens versus WiFi signals

    Hi, just a simple question. We've always been told that microwave ovens are dangerous and to not stand near them when they're on, obviously because they have the ability to heat up water molecules. I just read that the microwave frequencies they emit are 2.45 GHz. Wifi signals consist of 2.4...
  47. C

    Laser Guidance, Maglav Wagon, Wifi barrier

    Hey all! I am gearing up for next year to do a senior project, I want to knock it out in my spare time for the next 10 months. Ideas are: 1) Laser guided missile- 2 phase motor, one to go up then again to go to 'lazed' target. 2) Wifi barrier- setup focused jammers to create a 'wall'...
  48. J

    Why is my ASUS laptop blocking internet access on different WIFI networks?

    My wife has an ASUS laptop K53E series Notebook running Windows 7 Home Premium which she bought to use at her work (she is a teacher), the school part purchased with her and had the school IT set up everything. The problem started when the school IT wonk set up the WIFI to connect to the school...
  49. A

    Sensor with wifi output signal

    Hello I'm designing a project and i need a sensor that can detect human motion.I would like to detect the output signal of this sensor by searching it via laptop or mobile phone as if they are searching for a wifi signal. I would like to know if such sensor is available or should i build a...
  50. M

    Does a wifi client transmit when not associated?

    Does a wifi client (such as a laptop or phone) transmit anything prior to associating (or attempting to associate) with an AP? I suspect no, but I have searched the web and skimmed various specs and standards and I have not been able to find the answer. If you answer my question, please...