All You Need to Know About Wi-Fi
By Peter Edmonston, JumpWireless.org Network Administrator
Have you ever had trouble getting a connection to a Wi-Fi hot spot?
Have you ever wondered what makes a Wi-Fi network tick?
This article will describe the basics of how a Wi-Fi network/ hot spot functions and will offer tips on how to get a better connection to a wireless network.
What is a Wi-Fi network/hot spot?
The term Wi-Fi has been applied to many types of wireless capable devices. In order to be an actual Wi-Fi network, the device must be a device that has completed the Wi-Fi Alliance Interoperability Certification and comply with IEEE 802.11 standards. You can read about those here: http://standards.ieee.org/about/get/802/802.11.html. A device that has not yet completed or does not pass this certification will not be permitted to use the “Wi-Fi Certified” trademark (http://www.wi-fi.org/). Wi-Fi networks use 2.4 GHz and/ or 5 GHz RF (radio frequency) signaling. Communication regulatory agencies in any given country may have additional requirements with which devices must comply.
Generally, any wireless access point (AP) has been loosely defined as a “Wi-Fi network” or “Wi-Fi hot spot” by the average user.
Wi-Fi hot spots are common at coffee shops, fast-food chain restaurants, shopping centers, amusement parks, etc. Smart phones, tablets, and laptops can create hot spots to share an Internet connection. Home routers generate hot spots as well. Most businesses use unsecured hot spots for their customers and secured Wi-Fi networks for their internal traffic.
What are the benefits of Wi-Fi?
A big benefit of Wi-Fi networks is the elimination or reduction of the need for cables.
With Wi-Fi, there is no need to run wires through walls, above ceilings, or below floors. Also, there is no need to look up building codes or internal business policies to determine what you can and can’t do regarding cabling. Simply connect a Wi-Fi device at the Internet source and create a Wi-Fi network. Wireless networks can be extended by programming another Wi-Fi device to repeat the networks.
A large number of Wi-Fi networks can operate in the same location.
This benefit also has its downside. Because many Wi-Fi networks can operate in the same location, interference issues may arise when multiple networks utilize the same channel of the same band. On the upside, current Wi-Fi routers have the capability to auto select channels in an attempt to avoid interference. In some cases a Wi-Fi router set to a specific channel will work better. However, auto channel negotiation has one major issue. When the router changes channels, it momentarily drops all connections. In turn, this causes everyone to reconnect. This can disrupt communications, drop VoIP (Voice over IP) calls, disconnect video conferencing sessions, interrupt server connections, terminate remote management sessions, and the like. This issue can happen even though disconnect and reconnect times are momentary.
How does Wi-Fi work?
When a Wi-Fi router is set up, it will broadcast its signal in roughly a sphere.
Depending upon the strength of the signal and the level of interference, the signal will typically travel 20 to 60 feet in all directions. There are spots directly above and below the router that won’t go as far as the horizontal signal. This is because the sphere the router projects isn’t a perfect one. The broadcast signal has dimples in the top and bottom. See: http://en.wikipedia.org/wiki/Omnidirectional_antenna. Interference, low quality hardware, and cheap antennas can have a negative effect on the range of the router.
An upper limit has been placed upon how much a Wi-Fi network signal can be amplified. Think about it: if everyone would be permitted to broadcast as loud as they wanted, then nobody would be able to communicate. Manufacturers have come up with other ways to increase the range of Wi-Fi networks. The utilization of different types and qualities of antennas is a common tactic. An increase in the number of antennas and an alteration of their polarities is another strategy that is employed. Even if your router does not have an external antennas, it most likely has at least one internal antenna. Many Wi-Fi routers include one or more internal antennas as well as one or more external antennas. Some routers are capable of supporting external antennas with extension cables attached. This will allow for the placement of an antenna in a location that the router cannot be placed in order to improve coverage area.
How do you get a better Wi-Fi connection?
Beware of certain materials! Wi-Fi signals can be blocked or reflected by certain materials.
- Metal will block and reflect Wi-Fi signals.
- Steel mesh and metal siding will completely block Wi-Fi signals from passing through them.
- Steel beams, metal appliances, metal furniture, etc. will create shadows or dead spots behind them.
Think of the Wi-Fi router as a lamp with no lamp shade in a very dark room. The light will go out in all directions. Pretend everything around the Wi-Fi router that isn’t made of metal is made of transparent material. Imagine the metal objects are blocking the light cast from the lamp (Wi-Fi router) and casting shadows behind them. Any device that attempts to connect to the Wi-Fi router while in one of the shadowed areas will not be able to do so, because the signal is blocked.
Keep your Wi-Fi device away from metal objects!
If a Wi-Fi router or Wi-Fi device is sitting near a metal object like a filing cabinet, it may experience interference caused by reflections bouncing off the metal object.
Under certain conditions reflections can cause issues as well. When a Wi-Fi signal strikes a metal surface it will bounce from the metal surface in a scatter pattern. These reflections cause interference. The reflections are distorted and are seen as noise by wireless devices. http://www.radio-electronics.com/info/rf-technology-design/noise/electronics-radio-frequency-rf-noise.php Noise is RF signals, which are described in the following paragraph, present in an area that are unintelligible to the wireless devices at that location. If a Wi-Fi device is broadcasting and it is near a metal object, then the reflections will be much stronger than if the Wi-Fi device was farther away from the metal object.
Imagine the metal object is a speaker that distorts and rebroadcasts everything you and everyone else says. The closer you are to the speaker, the harder it will be to hear anything that you can understand.
RF and EM (electromagnetic) signals can cause interference within Wi-Fi networks. Microwave ovens, fluorescent lights, electric motors, and power lines are notorious for the noise-based interference they generate. http://en.wikipedia.org/wiki/Radio_frequency This can cause a significant reduction in performance of Wi-Fi and Ethernet cabled networks. The best way to avoid this type of interference is to be aware of it and keep Wi-Fi devices away from them. Microwaves, fluorescent lights, and power lines in the walls typically won’t travel more than a few feet. Electric motors and 3-phase power lines can have a much larger area of impact and will need to be handled on a case by case basis.
Use different polarities of antennas.
There is an easy way to accomplish this with common omnidirectional antennas. An omnidirectional antenna is one that will broadcast and receive signals in all directions at once. Simply align the antennas to different angles in relation with the ground. If you have a Wi-Fi router that has two or more external omnidirectional antennas, adjust one antenna so that it is vertical in relation to the ground and adjust another antennae so that it is horizontal in relation to the ground. This will cause the antennas to function with a polarity difference of 90 degrees. In some cases this will be enough to reduce the impact of interference and allow the network to function at a slightly longer range. It works best in situations where you need just a little bit more range in an environment where there are several other Wi-Fi networks present.
There are types of antennas that are directional as opposed to omnidirectional. Omnidirectional is typically what Wi-Fi routers use. Some routers come equipped with directional antennas. There are external directional antennas that some routers are capable of supporting. Directional antennas have an arc that they broadcast in. This arc is shaped like a cone with the point coming from the antenna and extending outward in one direction. This type of antenna can focus more of the energy into a smaller area, which improves the range of the network. This boosts the signal without amplifying it. If you focus one signal in a specific direction and broadcast another signal of equal amplitude in all directions, then the one that is focused will have more energy in the area of coverage. The one focused in a specific direction concentrates all of the energy that an omnidirectional antenna broadcasts everywhere into a smaller coverage area. This will only increase the range in the direction the antenna is facing. Unless there is a device using another directional antenna on the other end, the range increase will not be as big as it could otherwise be. Directional antennas are good when used to extend a wireless network to a location that is outside of the range of an omnidirectional antennae by equipping routers on both ends with a directional antenna.
So, now you know all you need to know about Wi-Fi, right? If not, please let us know if you have any questions. We want you to know everything there is to know about our service.
Please share any ideas you have about Wi-Fi or related topics by emailing BeSocial@JumpWireless.org, commenting on this page, or tweeting @JumpWireless. #JumpOnline #AffordableInternet #wireless #wifi