Wireless connections are much more than the dream of those who never managed to undo the mess between TV, video and console cables. Although the most popular is wifi, talking about wireless networks also means talking about satellites, mobiles, Internet and domotics among others.
Almost 30 years of research
Experts began researching wireless networks more than 30 years ago. The first experiments were carried out by one of the great giants in the history of information technology, IBM.
In 1979 IBM published the results of its infrared experiment in a Swiss factory. The engineers’ idea was to build a local network in the factory. The results were published in Volume 67 of the IEEE Proceeding and have been considered as the starting point in the evolutionary line of wireless networks.
The following investigations would be done in laboratories, always using high frequencies, until in 1985 the Federal Communication Commission assigned a series of bands to the use of IMS (Industrial, Scientific and Medical). The FCC is the U.S. federal agency in charge of regulating and administering telecommunications.
This assignment resulted in increased activity in the industry and LAN (local wireless network) research began to focus on the market. Six years later, in 1991, the first works of LAN itself were published, since according to the IEEE 802 standard only those networks that transmit at least 1 Mbps are considered LAN.
The local wireless network already existed but its introduction in the market and implementation at home and work would still be waiting a few years. One of the factors that supposed a great push to the development of this type of network was the settlement of Laptops and PDA in the market, since this type of portable product demanded more the necessity of a network without ties, without cables.
The creation of the wifi standard
Any wireless network is based on the transmission of data by electromagnetic waves, depending on the capacity of the network and the type of wave used we speak of one or another wireless network.
Wifi is one of them, in this case the range of the network is quite limited so it is used at home and office. That is why it is the most popular as many users have decided to remove the cables that allow the connection to the Internet. So it is possible to connect to the network from anywhere in the house.
The beginnings of any discovering are often difficult and one of the main problems you face is the implementation of a standard. That is why the main manufacturers of wireless networks decided to join forces to define the standards and facilitate the integration of wireless networks in the market.
Nokia, 3com, Airones, Intersil, Lucent Technologies and Symbol Technologies were the main sellers of wireless solutions in the 1990s. In 1999, Wireles Ethernet Compability Aliance, Wireless Ethernet Compatibility Alliance, was associated under the name WECA. Since 2003 the name of this association is Wí-Fi Alliance and now includes more than 150 companies.
The Wi-Fi Alliance is responsible for adopting, testing and certifying that the equipment complies with the standards they have set. Their goal has always been to create a brand that promotes wireless technology and ensures compatibility between devices.
The real name of wifi
In 2000, just one year after its formation, the still called WECA accepted as standard the IEEE 802.11b standard. The name was very non-commercial so the association hires the advertising company Interbrand to create a name much easier to remember, something short and simple. The proposals are various: “Prozac”, “Compaq”, “Oneworld”, “Imation” and, of course, “Wifi” the abbreviation of Wíreles Fidelity.
Wifi (802.11) was created to replace the physical and MAC layers of Ethernet (802.3). In other words, Wifi and Ethernet are the same networks that differ in the way the computer or terminal accesses the network, Ethernet via cable and Wifi via electromagnetic waves. This feature makes them compatible.
It is important to emphasize that Wifi is not a brand, it is the name of a standard. This means that all equipment with the wifi seal can work together regardless of the manufacturer who created the network or computer. So if in an office we have computers of different brands but all of them have wifi we will be able to connect them to each other without problems.
Currently Wifi is, above all, known as a tool to access the Internet but the truth is that it was designed as a local wireless network, to connect several devices within a short distance of each other. It is convenient not to forget this utility, because although it is less diffused it can contribute to the user many facilities and possibilities.
The most popular Wifi
The original standard is the 802.11, this has been evolving and now the possibilities of range and speed are various. Always talking about Wifi some variants are these:
- IEEE 802.11b and IEEE 802.11g, both have a band of 2.4 GHz the first reaches a speed of 11 Mbps and the second 54 Mbps. They are of the most widespread standards which gives them great international acceptance.
- IEEE 802.11a, better known as Wifi5 because its band is 5 GHz, having a higher frequency than the previous standard also has a shorter range, approximately 10% less. On the other hand, as it is a fairly new system there are still no other technologies that use it, so the Internet connection from the computer is very clean and without interference.
- IEEE 802.11n, it also works at 2.4 GHz but the speed is much faster than its predecessors, 108Mbps.
- Types of wireless networks
- As we said a few lines above, the types of wireless networks depend on their range and the type of electromagnetic wave used. According to their size we find the following networks, from smaller to larger range:
WPAN: (Wireless Personal Area Network): this type of network is used with technologies such as HomeRF, Bluetooth, ZigBee and RFID. It is a personal network of little range, the technologies that use it can connect the mobile phones of the house and the computers by means of a central apparatus. It is also used in the home as it requires secure communications with low data transmission rates and low power consumption.
WLAN: (Wireless Local Area Network) in the local area networks we can find wireless technologies based on HiperLAN (High Performance Radio LAN), or technologies based on Wi-Fi (Wireless-Fidelity).
WMAN: (Wireless Metropolitan Area Network, Wireless MAN) the most popular technology used by this network is WiMax (Worldwide Interoperability for Microwave Access), a wireless communication standard based on the IEEE 802.16 standard. It is very similar to Wi-Fi, but has more coverage and bandwidth. Another example is LMDS (Local Multipoint Distribution Service).
WWAN: (Wireless Wide Area Network, Wireless WAN) is the network used for second and third generation mobile phones (UMTS) and for mobile GPRS (digital technology).
The possible wave types are:
Radio waves: They are omnidirectional, do not need satellite dishes and are not sensitive to climatic changes such as rain. There are several types of band, can be transmitted with a frequency of 3 to 30 Hz and a maximum of 300 to 3000 MHz.
Terrestrial microwaves: The parabolic antennas are sent information, reaches miles but emitter and receiver must be perfectly aligned. Its frequency is from 1 to 300 Ghz.
Satellite microwaves: the information is forwarded from a satellite, it is the most flexible waves but it is easy to suffer interference.
Infrared: must be aligned directly, do not cross walls and have a frequency of 300 GHz to 384 THz.
Advantages and disadvantages of wireless networks
The main advantage is practically an obvious, mobility. But it’s more than just being able to access the Internet from the sofa or the desktop.
Historical buildings that do not allow the installation of cable or places too large as industrial buildings where wiring is unviable, are a good example of how this type of network can become indispensable.
On the other hand, access to the network is simultaneous and fast. At a technical level, it must be said that the relocation of terminals is simple and, consequently, their installation is quick. The main disadvantage is the loss of transmission speed with respect to the cable and possible interference in space.
In addition, being an open network can cause security problems, although more and more users have information and protection mechanisms such as the traditional and efficient password. In the 1990s, even the health of this network was questioned, a theory that has now been refuted.
So far we have talked about the advantages and disadvantages of wireless networks at the local level. The disadvantages arise when comparing the capacity of the cable with that of the LAN (popularly Wifi). But as we pointed out before, there are more types of wireless networks, some of them with large ranges that make kilometre connections possible.
In this case there is no possible comparison with the cable, they are pioneers and have opened great possibilities. A clear example can be found in the great evolution of mobile phones in recent years or in the possibilities of satellites.
Each type of wireless network has its own capabilities and limitations that encourage the needs of the user. Without a doubt, it is a technology with deficiencies that will be corrected in its evolutionary process and will still give us great surprises.