An introduction to WiFi, WiFi Standards, WiFi Certifications and Products

What is WiFi

Wi-Fi, or WiFi, is a wireless LAN technology that uses devices that are based on IEEE 802.11 standards. WiFi is a brand of the WiFi Alliance. It limits the use of the term guest wifi solutionsWiFi Certified to products that pass the interoperability certification tests. Devices that can use WiFi technology are quite varied. We also have computers, game consoles, smartphones; but also tablets, digital cameras, smart TVs, digital audio players, etc. WiFi enabled devices can connect to the internet via a WLAN and a wireless access point. Access point, or hotspot, has a range between 10 meters to 30 meters indoors and it can have a greater reach outdoors.

WiFi Invention

Australian radio astronomer John O’Sullivan and colleagues Terence Percival, Graham Daniels, Diet Ostry and John Deane have developed a key patent for WLAN technology. This patent comes from “a failed experiment to detect the explosion of mini-black holes the size of an atomic wifi6 wireless solutionsparticle.” Dr. O’Sullivan and his colleagues have somehow invented WiFi. In 1992 and 1996, CSIRO obtained patents for a method later used in WiFi to “not broadcast” the signal. The first version of the 802.11 protocol was released in 1997. It achieves link speeds of up to 2 Mbit / s. This was updated in 1999 with 802.11b to achieve link speeds of 11 Mbit/s.

Evolution of the WiFi Alliance

In 1999, the Wi-Fi Alliance became a trade association in order to own the Wi-Fi brand property; under which most products are sold. WiFi uses a large number of patents owned by many different organizations. In April 2009, 14 companies agreed to donate $ 1 billion to CSIRO for CSIRO patent infringements. This led Australia to qualify the Australian invention’s WiFi; although this has been outdoor wifi solutions controversial. CSIRO won another legal victory in 2012 and earned $ 220 million for WiFi patent infringement; companies in the United States to pay CSIRO license fees. These fees were estimated at $ 1 billion in additional royalties.

WiFi Certification

IEEE does not test equipment for compliance with their standards. The Wi-Fi Alliance non-profit was created in 1999 to fill this void. This allows the establishment and application of interoperability and backward compatibility standards. But also to promote wireless LAN technology.

In 2010, the Wi-Fi Alliance was made up of more than 375 companies worldwide. wifi solution The Wi-Fi Alliance applies Wi-Fi branding to technologies based on the IEEE 802.11 standards. This includes wireless LAN (WLAN) connections and device-to-device connectivity; the like WiFi Peer to Peer aka WiFi Direct. But also the personal area network (PAN), local area network (LAN) and even an extended area limited to network connections (WAN). Manufacturers who are members of the Wi-Fi Alliance, whose products pass the certification process, have the right to affix the Wi-Fi logo on their products.

Specifically, the certification process requires compliance with IEEE 802.11 radio standards, WPA and WPA2 security standards, and the EAP authentication standard. Then the certification may possibly include IEEE 802.11 project standards testing. As well as the interaction with cell phone technology in convergent devices and features relating to the configuration of security, multimedia and energy saving.hotel wifi solution

Not all WiFi devices are subject to certification. However, the lack of WiFi certification does not necessarily imply that a device is incompatible with other WiFi devices. The Wi-Fi Alliance may or may not sanction such drifts; such as the Super Wi-Fi, invented by the Federal Communications Commission (FCC) of the United States. This term describes the networking proposed in the UHF band in this country.

WiFi and the IEEE 802.11 standard

The IEEE 802.11 standard is a set of media access control (MAC) and physical layer (PHY) specifications for the implementation of wireless LAN (WLAN) computer communications in the 2.4 frequency bands. , 3.6, 5 and 60 GHz. They are created and maintained by the IEEE LAN / MAN Standards Committee (IEEE 802).

The basic version of the standard was published in 1997. Since then, it has undergone subsequent changes. Thus, the standard and the modifications form the basis of wireless network products using the Wi-Fi brand. However, although each amendment is formally revoked when it is incorporated in the latest version of the standard, the world of business tends to market revisions because they concisely state the capabilities of their products. Thus, on the market, each revision tends to become its own standard.guest-wifi solutions

WiFi and Internet access

WiFi technology can be used to provide internet access to devices within the reach of a wireless network connected to the internet. The coverage of one or more interconnected access points (hotspots) can range from as small as a few rooms to several square kilometers.cloud managed wifi solutions

Access points

Coverage in a larger area may require a group of access points with overlapping coverage. For example, open-air public Wi-Fi has been used successfully in wireless mesh networks in London, UK. The Fon wireless network is a good example. guest wifi solutions

WiFi is used at home as well as in businesses or public spaces. In the latter case, WiFi is set up for free or commercially. wifi6 wireless solutions He often uses a web page giving access to a captive portal to connect. Organizations and businesses, such as airports, hotels and restaurants, often offer free hotspots to attract customers.

Routers

Routers that incorporate a digital modem or cable modem and a WiFi access point are often installed in homes and other buildings. They provide internet and inter-network access to all wireless and wired devices. Similarly, battery-powered routers may include a cellular internet radio modem and a WiFi access point. Thus, if they have a SIM card, they allow neighboring outdoor wifi solutions WiFi stations to access the Internet via 2G, 3G or 4G networks; using the connection-sharing technique.

Many smartphones have an integrated capacity of this type. Including those based on Android, BlackBerry, Bada, iOS, Windows Phone and Symbian. “Internet packs” also provide standalone installations of this type, without using a smartphone; for example, thanks to MiFi and WiBro devices. Some laptops with a cellular modem card also allow them to serve as Wi-Fi hotspots. wifi solution

Smart City WiFi

In the early 2000s, many cities around the world announced plans to deploy WiFi networks across the city. There are many successful examples. First, in 2004, Mysore became the first WiFi city in India. A company called WiFiyNet has installed hotspots in Mysore; covering the entire city and some neighboring villages. Then, in 2005, St. Cloud, Florida, and Sunnyvale, California, became the first cities in the United States to offer free WiFi throughout the city hotel wifi solution.

In May 2010, Boris Johnson, mayor of London, promised to have a London-wide WiFi network by 2012. Several districts, including Westminster and Islington, already had extensive WiFi coverage outside of London. time. Officials from the South Korean capital, Seoul, have also offered to provide free internet access in more than 10,000 locations in the city; including outdoor public spaces, main streets and densely populated residential areas. Seoul will grant concessions to KT, LG Telecom and SK Telecom. Companies will invest $ 44 million in the project.

More recently, the European Union has unveiled the WiFi4EU initiative  . The goal: to install free public wireless hotspots in European municipalities that do not currently have any service or infrastructure.

WiFi for Educational Campuses

guest-wifi solutions Many traditional university campuses in developed countries offer at least partial WiFi coverage. For example, Carnegie Mellon University deployed the first campus-wide wireless network. Called Wireless Andrew, this network was deployed on the Pittsburgh campus in 1993; even before the appearance of the brand Wi-Fi.

In February 1997, CMU Wi-Fi was fully operational. Since then, many universities have collaborated to provide Wi-Fi access to students and staff through Eduroam’s international authentication infrastructure.

The WiFi radio spectrum

The 802.11b and 802.11g standards use the 2.4 GHz ISM band. Because of this choice of frequency band, 802.11b and 802.11g devices can sometimes be interfered with. This interference can come from microwave ovens, cordless phones and Bluetooth devices.

Frequency assignments and operational limitations are not uniform in the world. Australia and Europe allow two additional channels (12, 13); beyond the 11 allowed in the United States for the 2.4 GHz band. Finally, Japan has three others. In the United States and other countries, 802.11a and 802.11g devices may be used without a license; in accordance with FCC regulations.

A WiFi signal occupies five channels in the 2.4 GHz band. Any number of two channels that differ by five or more, such as 2 and 7, do not overlap.

The often repeated saying that channels 1, 6 and 11 are the only channels that do not overlap is therefore not accurate. Thus, channels 1, 6 and 11 are the only group of three channels that do not overlap … in North America and the United Kingdom. In Europe and Japan, it is recommended to use channels 1, 5, 9 and 13 for 802.11g and 802.11n.

802.11a uses the 5 GHz U-NII band, which in much of the world offers at least 23 non-overlapping channels. A big difference with the 2.4 GHz ISM frequency band, where adjacent channels overlap.

Service Set Identifier (SSID)

In addition to operating on different channels, several WiFi networks can share channels.

A set of services is the set of all devices associated with a particular WiFi network. The set of services may be local, independent, extended, or meshed. cloud managed wifi solutions

Each service set has an associated identifier, the 32-bit Service Set Identifier (SSID); which identifies the particular network. The SSID is configured in devices considered to be part of the network. It is transmitted in packets. Receivers ignore wireless packets from networks with a different SSID.

Construction of Robust and Secure wireless networks

Quite often there is a situation when you want to organize a seamless coverage of a large area and to manage the wireless network with a large number of access points. guest wifi solutions Let’s talk about how to optimally implement the project: where to start, what parameters to consider, how to set up the equipment and where the trick can wait. As a living example, choose our enterprise-class access points and network controllers.

At the first stage, it is necessary to decide what equipment and in what quantity will be needed to build the network. In this case, it is not only about controllers and access points. wifi6 wireless solutions A wireless network cannot function without its wired infrastructure. Therefore, at this stage it is necessary to take into account the wire segments, since it is quite likely that they will have to be modernized.

How to determine if the existing wired infrastructure is suitable for your wireless network? First, there should be enough free ports on the access switches to connect wireless equipment. In addition, the modern IEEE 802.11N / AC network provides subscribers with quite high access speeds, which leads to tougher speed requirements for wired interfaces, as well as performance of the wired part of the network as a whole.

Secondly, to optimize the power supply circuit, modern access points can receive power not only from an external source, but also through a network cable using PoE technology outdoor wifi solutions (IEEE 802.3af or 802.3at, depending on the model) – but in order for this to work, access switches must also support this technology.

Third, access switches must be managed and supported by virtual networks (VLANs), which is necessary when wireless equipment uses multiple SSIDs. Fortunately, almost all switches used in the corporate segment can do this. Finally, you may have to make changes to the SCS – it depends on the total number of access points and their installation sites wifi solution.

But how to understand how many access points you need to install? At a minimum, to pay attention not only to the general plan of the premises, but also to places of mass gathering of users, as well as the number of people who can simultaneously use the connection in each of them. At the same time, places of mass gathering are not only conference halls or work rooms of employees, but also shopping centres, educational institutions, hotel lounges, elevators, cafes and restaurants and other areas that are less obvious at first glance. In fact, here, competent radio frequency intelligence is indispensable. And here we have the opportunity to help our customers do radio planning and conduct radio frequency surveys, for which we have the appropriate hardware and software. hotel wifi solution However, a rough estimate of the number of access points depending on the density of users can be made immediately.

Need of Wireless Controller

Do you need a controller if you have only a few access points? The answer to this question is a little more complicated than it might seem at first glance. The architecture of modern wireless networks has changed, and now a couple of access points will be enough only for a very small network. Previously, at each site of the network coverage was provided by one access point with a transmitter at maximum power. In modern networks it is recommended to make a distributed installation of two or more access points whose transmitters are not used at full capacity. guest-wifi solutions This architecture allows you to fully utilize the wired infrastructure, as well as to achieve higher client connection speeds through the use of complex modulations, available only with close mutual location of the access point and the wireless client.

The modern wireless network architecture also provides additional insurance in case of equipment breakdown: if one access point fails, its functions will temporarily be taken over by neighbouring wireless devices, which would be impossible if it were alone responsible for the site. 

Using the 5GHz band allows you to unload the 2.4 GHz problem frequency, however, the higher frequency signal is absorbed more by various obstacles located between the receiver and the transmitter, which in some cases significantly reduces the coverage area of ​​the network operating at 5GHz, and again brings us to the need to increase the grouping of access points at the facility.

The procedure for deploying a wireless network is quite transparent and consists of several simple steps. We should start with the preparation of the network infrastructure for the introduction of the wireless segment. For definiteness, we assume that it is necessary to provide coverage with a wireless network at the facility, which is one building or a group of closely located buildings connected by a local area network. EZELINK wireless equipment has the ability to remotely connect access points to the controller, however, for simplicity, we assume that all connections are made within one local cloud managed wifi solutions network.

We decided to somewhat complicate the task of pilot implementation and use the existing wired infrastructure built on the basis of equipment from another manufacturer, as well as to place the controller and access points on different subnets.

Network traffic patterns

Depending on the relative position and settings of the wireless controller, access points and the wired network segment, several typical patterns of user traffic are possible. They need to be considered when designing a wireless network to avoid overload in the wired segment.

Access points connect directly to the wireless controller

This model can usually be found in small wireless networks where the number of access points is relatively small. Access points can be connected either directly to the ports of the wireless controller or to auxiliary switches with or without PoE support.

Regardless of whether the controller performs the switching or routing of user traffic, the link between the switch and the controller may be a bottleneck.

The controller acts as the default gateway for wireless networks.

This model does not regulate the mutual arrangement of the wireless controller and access points in the network. The fundamental fact is the configuration of network equipment and client devices, in which the controller acts as a default gateway for wireless clients. In this case, the link between the switch and the controller will also be overloaded.

The default gateway functions are assigned to a router or L3 switch.

This model is optimal from the point of view of performance, since the wireless controller is completely excluded from the transmission path of user traffic. Access points essentially act as bridges, associating a wireless SSID with a VLAN in a wired segment. All further traffic processing is done by wired switches and routers.

EZELINK wireless controller is capable of routing traffic for two Gigabit Ethernet ports at an environment speed in Full Duplex mode, fully utilizing the resources of both processor cores and users will be able to get a total of 2 Gbit/s large packets in total.

It is impossible not to notice that the traffic switching is carried out by the controller practically without using the central processor, which allows using all five Gigabit Ethernet ports in L2 mode at the speed of the environment, while leaving the central processor resources free for other tasks.

The AC1750 Access Point provides users with a maximum theoretical speed of 750 Mbps in the 2.4 GHz band and 1.3 Gbit/s in the 5 GHz band. In practice, when using the AC1750 model in the 2.4 GHz band, the total speed of simultaneous transmission of user data in both directions is about 260 Mbit / s. For the 5 GHz band, this value is 620 Mbps.

Thus, in practice, one access point AC1750 will be able to transmit about 900 Mbit / s of traffic to a wired network when wireless clients are connected to both frequency bands. These speeds should be considered when building or updating a wireless network, reducing the oversubscription in the wired segment whenever possible.

Firmware update

The wireless controller and access points are ready to work right out of the box, but we always strongly recommend updating the software that is pre-installed on the devices. The new firmware will not only fix the detected inaccuracies in the code, but also add new features. For example, one of the most interesting new products for our equipment will be support for cloud management, which allows you to centrally manage several wireless controllers at once. This option will be in demand in the case of very large or distributed objects. We are also implementing IPv6 support, which will allow us to use our wireless equipment in new generation IP networks. For network administrators, we have added support for the SNMP protocol, with the help of which it is possible to centrally control devices and collect statistics on the use of the controller and access points. As well as command line support.

When building a wireless network on a large or complex site, you need a lot of wireless access points to provide a continuous coverage area. They are managed (in FIT mode) in this case using a wireless controller. To update their firmware, you also need to use a controller. A centralized change of firmware versions of access points is performed using the controller’s web interface, where you need to download a file containing the new firmware version, as well as specify the start time for the update. Also here you can view a list of access points that it affects.

The ability to centrally update is especially useful for the wireless controller, since this model supports up to 500 access points at the same time, which makes manual replacement of firmware on a tracking object almost impossible.

Since our range of equipment is constantly updated, after the release of a new model it is necessary to update the database of supported devices on the controller in order to expand the list of controlled equipment.

Installation and configuration of EZELINK equipment is extremely simple, and a large number of changeable parameters allows you to flexibly configure the network in accordance with all the wishes of the customer. Below we list the key features of our products that we consider to be the most popular and relevant when building large-scale networks:

Automatic detection and centralized management of access points;

  • The ability to locally and remotely locate access points
  • Load balancing
  • Support of local switching of user traffic by access points
  • Unified customization
  • PoE support
  • Support for multiple SSIDs
  • Various user authentication methods
  • Flexibility and scalability of the solution