Posted on : By : Roméo Diaz Posted in : Non classé

Understand the institutions linked to Wi-Fi

Air is a shared media, so many equipments must be able to communicate at the same time, sometimes with each other and especially without disturbing each other. Moreover, the frequencies used by Wi-Fi are also used by other systems (radar, microwave, presence detector, …) which do not communicate. In order for all this equipment to work in harmony, it is necessary to write standards to define the spaces reserved for each, the conditions of cohabitation and the rules of communication. We therefore find different organizations working together.

Wi-Fi Alliance

The Wi-Fi Alliance (previously named Wireless Ethernet Compatibility Alliance) is a global non-profit organization, founded in 1999. Its mission is to ensure the interoperability of equipment based on the IEEE 802.11 standards. For this purpose, it relies on different programs:

Connectivity: This program aims to ensure that data transmissions are carried out in the expected manner in compliance with 802.11 standards. We currently find the following programs:

  • Wi-Fi 6
  • Wi-Fi ac
  • Wi-Fi Halow (using a frequency band below 1GHz)
  • Wi-Fi n (still maintained for the IoT)
  • Wi-Fi WiGig (using a high performance 60GHz frequency band)
  • Wi-Fi Direct

Security: The equipment must ensure a minimum of security in their exchanges, for this we find the following programs:

  • WPA3
  • Wi-Fi Enhanced Open
  • Protected Management Frames

Access: The equipment can use one of the following methods to authenticate itself on the network:

  • Passpoint (currently being upgraded to Vantage which provides more flexibility)
  • Wi-Fi Easy Connect
  • Wi-Fi Protected Setup (WPS)

Application and services: Various features to enhance the user experience are offered in this program. They include:

  • Miracast (Transmission of HD and UHD video content)
  • Voice enterprise (VoIP enhancement)
  • Wi-Fi Aware (Detection of nearby equipment)
  • Wi-Fi Location (Allows geolocation of equipment without GPS connectivity)

Optimization: This program provides solutions to improve the quality of exchanges, here are some examples of features that we find:

  • Wi-Fi Agile Multiband (Optimization of the choice of terminals and channels)
  • Wi-Fi Optimized Connectivity (Optimizes roaming through quality assessment)
  • Wi-Fi Multimedia (WMM) (Multimedia traffic prioritization)

RF Coexistence: This program assures that Wi-Fi equipment can coexist with other non-802.11 equipment, there is currently only one program that is still under study:

  • CWG-RF which studies the interaction of radios on a cellular and Wi-Fi terminal

Institute of Electrical and Electronics Engineers (IEEE) :

IEEE is a global society with approximately 400,000 employees in 160 countries. The main objective of the IEEE is “To foster innovation and technological excellence in the service of people”. To do this, they create standards on which manufacturers can then build to make equipment interoperable and able to communicate with each other.

In order to write or revise standards, the IEEE sets up working groups to which a number is associated in an incremental manner. The first standard that was written was named 802.1 and is a working group on the interconnection of different networks defined in the following standards. Probably the two most known are 802.3 which corresponds to the standard defining the Ethernet and 802.11 which defines the WLAN type network. Once the standard is defined, it is regularly completed and revised by Tasks Groups and one or more letters are added to the standard number, always in an incremental way.

Internet Engineering Task Force (IETF)

The IETF is a standards organization that develops and promotes Internet standards. It is an open organization where all participants are volunteers and there are no membership requirements. The IETF was initially supported by the U.S. government before becoming in 1994 managed by ISOC (Internet Society) which is also a non-profit organization.

The IETF works around eight main themes which are : Applications, a global theme, Internet, Operations and Management, Applications and Real-Time Infrastructure, Routing, Security and Transport. From these themes, many working groups will be created to participate in the development of RFCs (Request for Comments) that will describe network protocols, services or certain rules that can evolve into a standard. Not all RFCs will become standards. Concerning Wi-Fi, many documents (standards, best practices or information documents) provided by the IETF concern security

International Organization for standardization (named ISO)

ISO is a non-governmental certification organization that is found in many fields (security, management, etc.). From a network point of view, ISO is the basis of the OSI model (Open System Interconnection) which governs all data communications. This model is divided into 7 layers:

Application

Presentation

Session

Transport

Network

Link

Physical

International Telecommunication Union Radiocommunication Sector (ITU-R)

The ITU-R is an organization under the responsibility of the United Nations which is in charge of the Radio Frequency spectrum at the global level in order to avoid interference on land, in the sky and on the sea. It maintains a worldwide basis on frequency allocations. For this, it relies on 5 organizations that manage specific regions:

  • Region A: Americas (Inter-American Telecommunication Commission – CITEL)
  • Region B: Western Europe (European Conference of Postal and Telecommunications Administrations – CEPT)
  • Region C: Eastern Europe and Northern Asia (Regional Commonwealth in the field of Communications – RRC)
  • Region D: Africa (African Telecommunication Union – ATU)
  • Region E: Asia, excluding North Asia and Australia (Asia Pacific Telecommunity – APT)

Within these regions, local regulatory bodies direct the management of the radio-frequency spectrum in their respective areas, in accordance with ITU-R recommendations. Examples of such bodies include:

  • The Federal Communications Commission (FCC) for the United States
  • The European Telecommunications Standards Institute (ETSI) for Europe
Posted on : By : Roméo Diaz Posted in : Non classé

Different Wi-Fi surveys

A Wi-Fi coverage is an essential element to ensure the proper functioning of equipment. This requires an optimized positioning of the access points in relation to the different environment (wall, interferences, …). To achieve this, we will rely on different studies: Plan survey, AP on a stick survey and active and passive survey. These different surveys have their own advantages and disadvantages, but above all they have different objectives and are generally complementary. We will therefore list and present them in the rest of this article:

Plan survey

A plan survey is a study that allows, with the help of a software that simulates the propagation of radio waves, to position the Wi-Fi terminals in the right places, taking into account the constraints of the site. These constraints, such as walls, exclusion zones or on the contrary higher densities, must be indicated by the engineer in charge of the study. The accuracy of this study depends directly on the quality of the values indicated, which is why this methodology is often used in addition to another audit that will serve to validate the accuracy of the values. Once the various constraints have been entered, this audit methodology offers the possibility to quickly simulate several scenarios and installations.

AP on a stick survey

An AP on a stick survey is an on-site survey, carried out with the help of an access point that will be used during the installation, as well as a battery and a pole that will allow the access point to be temporarily installed at the various recommended locations and to be easily moved. The purpose of this study can be to measure the attenuation of the walls, to validate that the signal propagation simulated by the software is consistent. Using this methodology brings precision to an audit on plan by allowing the use of more precise values, because measured directly on site.

Active vs. passive survey

Once the solution is installed, there are two types of audits, active and passive. These surveys can be performed to validate a Wi-Fi coverage or to identify possible interferences or disturbances. The active study is based on exchanges between the access point and the measurement tool and therefore requires to be connected. This type of audit is therefore relatively limited, because the analysis is only done on the access point to which we are connected and not on all the access points. This type of audit is therefore rarely performed alone, but rather as a complement to a passive study.

Unlike active audits, passive audits do not require any authentication and simply listen to all 802.11 frames and allow you to see all the surrounding channels and networks (depending on the capabilities of your measurement tool). This type of audit allows you to observe, among other things, possible co-channel interference.

It is also recommended in parallel to these surveys to perform a spectral analysis to identify any interference not related to Wi-Fi. The radio frequency environments on the frequency bands related to Wi-Fi is constantly evolving, and many terminals are added. It is therefore essential that the audit process is carried out regularly to anticipate problems.

The realization of these audits allows deploying and validate a good Wi-Fi coverage, however the realization of functional tests is necessary. Indeed, the reality of the measurement tools is not always that of the different terminals even if some tools allow applying compensations. The functional validation also allows validating that the whole communication chain is good and that all the equipments support the protocols and encryption proposed by the Wi-Fi terminals.