Wireless technologies for data transmission. Wireless networks for IoT and M2M. Basic Data Transfer Mechanisms

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Wireless data transmission systems

Introduction

Currently, wireless data transmission systems have become widespread in most areas of society.

They owe this attention to:

Low cost

Mobility

Independence from cable infrastructure

· High-speed Internet access

Easy to connect and use

The development of wireless access systems goes in three main directions:

1. Satellite systems

2. Personalized systems cellular communication

3. Terrestrial microwave systems

Each of these means has its own advantages and disadvantages. Wireless networks are most effective when transmitting data over a distance of several hundred meters.

1. The evolution of wireless networks

Until quite recently, mobile phones were really phones, not smartphones as they are now. These "ancient" devices could support a minimal set of functions, for example, make calls and send text messages. It's good that those days are behind us and promising new generation wireless high-speed data networks have begun to actively appear around the world, and some things are starting to seem confusing. Note first that the prefix "G" means "generation" (from the English generation).

1.1 1G

The story begins with the advent of several network technologies in the 1980s: a combination of NMT and TACS in Europe and AMPS in the USA. The trio of NMT, TACS and AMPS are considered the first generation of 1G wireless networks, because it was these technologies that allowed mobile phones, in the form in which we now see them, to become a mass product. In those days, the data transmission service did not even occur to anyone, since these were purely analog systems, invented and designed exclusively for voice calls and some other modest features. Also, the data transfer speed was low and expensive.

1.22G

The early 1990s saw the rise of the first digital cellular networks, which had higher sound quality, increased performance, greater security, etc. GSM began its development in Europe.

The second generation of the 2G wireless network already had support for short text messaging (SMS) as well as data transfer technology (CSD - a data transfer technology developed for GSM mobile phones) that allowed data to be transmitted in digital form. All this made it possible to increase the data transfer rate to 14.4 kbps.

1.3 2.5G

GPRS service appeared in 1997. Its appearance was a turning point in the history of wireless cellular communications, because with its advent, existing GSM networks began to support continuous data transmission. With GPRS, you can only transfer data when you need it. The GPRS speed was higher than the CSD speed and theoretically reached 171.2 kbps, and the operators got the opportunity to charge not for the time on the line, but for the traffic.

The jump in popularity of GPRS in such a short time is explained by the fact that people began to actively check their mailboxes. When GPRS technology was already on the market, the International Telecommunication Union (ITU) published new standard- IMT-2000 approves 3G specifications. The main thing in this story is that 3G devices must provide data transfer rates up to 2 Mbps for fixed terminals and 384 kbps for wireless networks, which was beyond the power of GPRS. Thus, GPRS was stuck between generations, 2G - which it excelled, and 3G - which it fell short of.

1.4 3G, 3.5G, 3.75G

In 2003, the EDGE standard was provided for the first time in North America. This standard allowed GSM network operators to squeeze more juice out of 2.5G networks without investing heavily in equipment upgrades. With an EDGE-enabled mobile phone, subscribers could get speeds that were twice as fast as GPRS, which was quite good for that time.

In 2004, North American GSM operators supported EDGE. This was due to the emergence of a strong competitor CDMA2000. It provides a data transfer rate slightly higher than GPRS. Most other GSM operators considered UMTS technology as the next step in their development, so they chose to either skip the introduction of EDGE. However, as practice has shown, the high cost and scope of work for the implementation of UMTS forced some European operators to reconsider their view of EDGE as expedient.

Some time later, CDMA2000 wireless networks received the 1x EV-DO Rel.0 update. The update increased the incoming speed to 2.4 Mbps and the outgoing speed to 153 kbps. Thus, we got 3.5G.

The 3.5G transition generation is represented by the HSDPA standard.

For cellular networks today, there are several protocols that increase the speed of data transfer. However, in fact, none of them is able to save mobile network resources, which makes such traffic expensive and inefficient. Conceived by leading infrastructure equipment manufacturers mobile communications HSDPA protocol is designed to improve network performance precisely due to more effective use radio channel, in particular by reducing delays in the transmission of packets. HSDPA technology does not carry anything new, but changes the user's perception of third generation mobile data networks.

HSDPA (High-Speed Downlink Packet Access - high-speed packet data transfer from a base station to a mobile phone) is a mobile communication standard considered by experts as one of the transitional stages of migration to fourth-generation mobile communication technologies (4G). The maximum theoretical data transfer rate according to the standard is 14.4 Mbps, the practical achievable in existing networks is about 3 Mbps.

1.54G

Just like 3G, the ITU has taken control of 4G by tying it to the IMT-Advanced specification. The specification sets the incoming data rate at 1 Gbps for fixed terminals and 100 Mbps for mobile devices. These are really huge speeds that can overtake even a direct connection to a broadband channel.

No commercial standard conforms to these specifications, but WiMAX and LTE have traditionally been considered 4G technologies, but this is only partly true, as they both use new, extremely efficient multiplexing schemes, and they both lack a channel for voice transmission. . We can confidently say that 100% of them bandwidth used for data services.

As practice has shown, WiMAX and LTE have failed in data transfer speed. Theoretically, the speed values are at the level of 40 Mbps and 100 Mbps, but in practice, the real speeds of commercial networks do not exceed 4 Mbps and 30 Mbps, respectively. This fact does not meet the high requirements of IMT-Advanced. Only upgrades to WiMAX Release 2 and LTE-Advanced were able to achieve these speeds.

1.6 5G

Far from all major cities have deployed fourth-generation LTE networks, and telecommunications companies are already making plans for fifth-generation (5G) services. For example, the Japanese NTT DoCoMo believes that the launch of such networks will become possible in 2020: compared to LTE, they will provide a hundredfold increase in data transfer speed and a thousandfold increase in bandwidth.

Researchers from the Chalmers University of Technology (Sweden) told what infrastructure changes may be required when implementing 5G technologies.

Let's start with some statistics. In 2012, there were 1.2 billion cellular smartphone subscribers. By 2018, this number is projected to rise to 4.5 billion. Mobile traffic doubled between the first quarters of 2012 and 2013, and by the end of 2018 it will jump another 12 times.

It is clear that the growth in the number of mobile devices with a web connection will lead to a sharp increase in the load on data channels and will create a need for increased speed. 5G networks should be the solution to the problem.

Researchers identify five main directions in the scenario for the development of next generation communication systems. This is a multiple increase in speed compared to 4G / LTE, the ability to provide quality services even in the most densely populated areas, maintaining a stable connection with a large number of devices with a web connection (we are talking about the "Internet of Things"), high quality of services for end users and minimal delays.

At the beginning of the year, the European Commission allocated €50 million for research related to fifth generation mobile communications. Grants are provided to scientific organizations and scientists involved in communication technologies. For example, participants in the METIS (Mobile and wireless communications Enablers for the Twenty-twenty Information Society) project, which involves Technical University Chalmers received €16 million.

METIS has already defined the basic requirements that 5G networks must meet:

1. An increase in the data transfer rate by 10-100 times per subscriber - up to 1-10 Gbit / s.

2. Growth of consumed traffic by 1,000 times - up to 500 GB per user per month.

3. Increase in the number of connected devices by 10-100 times.

4. Tenfold improvement in battery life for low power devices such as sensors.

5. Reducing the response time of systems to 5 ms or less.

6. Preservation of the previous cost of operation and energy costs.

One of the proposed ways to solve these problems is to install small, low-power base stations in homes, on streetlights, and even on cars and public transport. This will reduce the distance between the information transmitter and the end user and, consequently, increase the efficiency of the main base stations and increase the data transfer rate.

In addition, compacting the infrastructure of base stations will reduce the radiation intensity and improve the energy efficiency of all devices without exception by reducing the signal strength.

In essence, the researchers say, fifth-generation networks will create the foundation for an intelligent community where people and devices can communicate anywhere, anytime.

2. Classification of wireless technologies

There are various ways to classify wireless technologies

2.1 By range

Figure 1 - classification of wireless technologies by range

Personal wireless networks

Wireless Personal Area Networks( WPAN) - networks used to communicate between different devices. The range of WPAN can reach several meters.

Local Area Networks (WLAN)

In such a network, data transmission is carried out via radio. The most common representatives of such a network are Wi-Fi and WiMAX.

Wide Area Networks (WWAN)

WWAN differs from WLAN in that they use cellular technologies such as GSP and GPRS.

Citywide Networks (WMAN)

Such networks provide broadband access to the network through a radio channel.

By topology

Point-to-point networks

A point-to-point network is the simplest type of computer network in which two computers communicate through communication equipment.

Point-to-multipoint networks

Such networks are used to connect three or more objects.

2.2 By scope

2.2.1 Corporate networks

A corporate data network is a system that provides information transfer between various objects that are used in a corporation's system. They are created by companies for their own needs.

2.2.2 Operator networks

Operator networks are called such networks that are created by telecom operators for the provision of paid services.

3. The most common wireless data networks

3.1 Bluetooth

The most striking example of wireless personal area networks is Bluetooth. It provides data transfer between personal devices such as laptops, smartphones, tablet computers, etc.

Bluetooth is a specification for WPAN networks. Being a wireless personal area network, Bluetooth connects personal devices (laptops, mobile phones, mice, headphones, GPS adapters, etc.) into one whole. It operates in the 2.4 GHz frequency range, the distance, depending on the network class, can be from one to one hundred meters.

Bluetooth versions:

· Bluetooth 1.0, 1.1, 1.2, 2.0, 2.1. These specifications are obsolete and are not built into new devices. Of interest are other, more modern options.

· Bluetooth 2.1 + EDR (Enhanced Data Rate). Data transfer rate up to 2.1 Mbps.

· Bluetooth 3.0 + HS (High Speed). Includes two subsystems - for high speed (theoretical maximum 24 Mbps) and for low power consumption (up to 3 Mbps). Switching occurs automatically depending on the needs.

· Bluetooth 4.0. Added Bluetooth low energy specification. It is intended for small sensors (for example, in shoes, exercise equipment), the battery life of such sensors can reach several years. Peak transfer rate up to 1 Mbps.

Different devices can support all sorts of protocol extensions called profiles. The user is most interested in the following profiles:

A2DP (Advanced Audio Distribution Profile). Designed to transmit stereo sound (for example, to headphones). There is a version for the receiver and transmitter. Devices with A2DP can support all sorts of codecs like MP3, AAC, etc.

· File Transfer Profile (FTP_profile). File transfer, directory listing.

HID (Human Interface Device Profile). Support for input devices - mice, keyboards, joysticks. Requires less energy.

3.1.1 How it works

Operating principle Bluetooth is based on the use of radio waves. Bluetooth radio communication is carried out in the range of 2.4-2.4835 GHz (ISM band). Bluetooth uses frequency hopping spread spectrum (FHSS).

According to the FHSS algorithm, Bluetooth's carrier frequency hops 1600 times per second. The sequence of switching between frequencies is known only to the transmitter and receiver, which every 625 microseconds are synchronously tuned from one carrier frequency to another. Thus, if several pairs of receiver-transmitter work side by side, they do not interfere with each other. This algorithm is also an integral part of the system for protecting the confidentiality of transmitted information: the transition occurs according to a pseudo-random algorithm and is determined separately for each connection.

Bluetooth protocol supports not only point-to-point connection, but also point-to-multipoint connection

3.1.2 Advantages

Bluetooth does not require line of sight between devices for synchronization. This means that the devices do not have to face each other, and it is also possible to transmit when both devices are in separate rooms. The fact that this technology does not require wires and cables has made it so popular. The maximum range that Bluetooth can transmit is 100 meters, but this range is not the same for all Bluetooth connections. It depends on the characteristics of the device and its version.

One of the main advantages of Bluetooth is its ease of use. Anyone can understand how to set up the connection and synchronization of two devices. In addition, the technology is absolutely free to use. Bluetooth 2.0 introduced support for multi-cast, that is, sending data to multiple devices at the same time. The chance of other wireless networks interfering in a Bluetooth network is very low. This is due to the low power of wireless signals and frequency hopping. Bluetooth operates in the same frequency range as Wi-Fi 2.4 GHz. In some very rare cases, connections may conflict with each other.

3.1.3 Disadvantages

The main disadvantage Bluetooth is low security. There are many spyware hacks out there now that allow you to get into your device if Bluetooth is enabled. Battery wear during a single Bluetooth transmission is not significant, but there are some people who leave Bluetooth enabled on their devices. This is unavoidable, greatly reducing battery life.

3.2 WiFi

Wi-Fi - wireless networks based on the IEEE 802.11 standard.

Figure 3 - Wi-Fi logo

WiFi Standards:

1. IEEE 802.11b - Describes faster transmission rates and introduces more technology restrictions. This standard was widely promoted by WECA (Wireless Ethernet Compatibility Alliance) and was originally called Wi-Fi. Frequency channels in the 2.4GHz spectrum are used. Ratified in 1999. RF technology used: DSSS. Maximum data rates per channel: 1, 2, 5.5, 11 Mbps

2. IEEE 802.11a - describes significantly higher transmission rates than 11b. Frequency channels in the 5GHz spectrum are used. RF technology used: OFDM. Protocol Not compatible with 802.11b. Ratified in 1999. Maximum data rates per channel: 6, 9, 12, 18, 24, 36, 48, 54 Mbps.

3. IEEE 802.11g - describes data rates equivalent to 11a. Frequency channels in the 2.4GHz spectrum are used. The protocol is compatible with 11b. Ratified in 2003. Used RF technologies: DSSS and OFDM. Maximum data rates per channel: 1, 2, 5.5, 11 Mbps for DSSS and 6, 9, 12, 18, 24, 36, 48, 54 Mbps for OFDM.

4. IEEE 802.11n is the most advanced commercial Wi-Fi standard at the moment. Frequency channels in the 2.4GHz and 5GHz spectra are used. Compatible with 11b/11a/11g. Although it is recommended to build networks with a focus on 11n only, since special protection modes must be configured if backward compatibility with legacy standards is required. This leads to a large increase in signaling information and a significant decrease in the available useful throughput of the air interface. Actually, even one 11g or 11b client will require special tuning of the entire network and its instant significant degradation in terms of aggregated performance. The 802.11n standard itself was released on September 11, 2009. 20MHz and 40MHz (2x20MHz) frequency channels are supported. RF technology used: OFDM.

3.2.1 How Wi-Fi works

Typically, a Wi-Fi network scheme contains at least one client and one access point. Also, in point-to-point mode, when an access point is not used, and clients are directly connected by network adapters, it is possible to connect two clients. At a speed of 0.1 Mbps, the access point transmits its network ID using special signaling packets every 100 milliseconds. Therefore, 0.1 Mbps is the lowest data rate for Wi-Fi. Knowing the network ID, the client can find out if it is possible to connect to this access point. When two access points with identical network IDs come into range, the receiver can choose between them based on signal strength data.

3.2.2 Benefits

Possibility deploy a network without laying a cable, which reduces the cost of deploying and expanding the network. Wireless networks serve places where it is impossible to lay a cable

Allows mobile devices to access the network.

Wide distribution in the market. Guarantee of equipment compatibility due to mandatory certification of equipment of this brand.

Mobility.

In the Wi-Fi zone, several users can access the Internet from portable devices and computers.

Radiation from devices using Wi-Fi at the time of data transfer is 10 times less than the radiation of a cell phone.

3.2.3 Disadvantages

In the range of 2.4 GHz, there are many devices that support other types of wireless networks that degrade electromagnetic compatibility.

The WEP encryption standard can be broken relatively easily even with the right configuration (due to the weak strength of the algorithm). There is WPA(2) encryption, but in point-to-point mode, the standard only requires 11 Mbps (802.11b) to be implemented. WPA(2) encryption is not available, only easily crackable WEP.

3.3 WiMAX

A telecommunications technology based on the IEEE 802.16 standard, also known as Wireless MAN.

3.3.1 Operating principle

WiMAX networks consist of several parts - base and subscriber stations, as well as equipment that connects base stations.

Base and subscriber stations communicate using radio waves in the range of 1.5-11 GHz. Data exchange can occur at a speed of 70 Mbps.

Base stations are connected by line-of-sight connections at a frequency of 10-66 GHz, and the data exchange rate reaches 120 Mbps.

3.3.2 Benefits

WiMAX technologies will help organize wireless access throughout the territory settlements contributing to problem solving last mile", as well as reducing financial costs for new connections. If now the connection of one object can take up to several months, then with WiMAX-based solutions this process will be reduced to several hours or days. Savings on the organization, laying and operation of structured cable networks (SCS) , as well as the speed of installation and connection of equipment will significantly reduce investments in telecom infrastructure.WiMAX technologies provide not only voice transmission, but also any data, including video conferencing, Internet access, corporate networks and databases. WiMAX is a fairly low security of information transmitted over radio channels.Now this issue is being addressed by the manufacturers of the relevant equipment.Nevertheless, WiMAX technology can be widely used in the organization of corporate data transmission networks.

3.3.3 Disadvantages

Weather conditions and other wireless systems can interfere with the normal functioning of radio access, completely different frequency bands can be used for operation, the data transfer rate drops rapidly with increasing distance between the base station and client equipment, the equipment is demanding on power supply and consumes quite a lot of power.

3.4GPRS

3.4.1 How it works

Using GPRS information is collected in packets and transmitted through voice channels that are not currently in use. The transmission priority (voice traffic or data transmission) is chosen by the telecom operator.

3.4.2 Advantages and disadvantages

The advantages of GPRS are the ability to connect to the Internet, being anywhere in the world where there is a cellular connection, high data transfer speed, which allows you to quickly organize connections to the Internet and work with comfort, compactness and mobility.

The disadvantages of GPRS are too high cost of one Mb of information and the lowest access speed.

Conclusion

wireless network communication

Currently, wireless data transmission systems are an integral part of every person's life. Wireless networks are improving every year faster and faster, specifications systems are vastly improved.

The improvement of wireless data transmission systems can trigger the development of technologies such as cloud storage. If the data transfer speed is very high, the need for hard drives may disappear.

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Oleg Ivanin for website

Wireless technologies are experiencing a true boom in development today. This is mainly due to the solid entry into our lives of smartphones, tablets and mobile computers, which, among other things, can serve as universal control panels for automated process control systems, provided that there is constant access to the Internet, regardless of whether the terminal moves in space. Moreover, in various industries, agriculture, in the military sphere, there is a need to organize reliable systems for managing distributed objects and their integration into a global network. Similar trends are observed all over the world and lead to the inevitable development of wireless communication technologies.

APCS systems, which are often distributed, are currently characterized by a trend of modernization, provided that the main means of production (lines, machines and mechanisms) remain unchanged. The quality of production is changing in a short time due to the modernization of automated process control systems, including the use of wireless technologies, which save money and time compared to the deployment of wired networks.

This article discusses, and in part compares, various products from wireless communication hardware manufacturers covering applications such as industrial process control systems and building management systems (BMS) control systems.

The types of wireless networks that are applicable in these areas are as follows:

Personal wireless networks.
Wireless sensor networks.
Small local wireless networks.
Large local wireless networks.

In our review, we do not consider hardware and software for the organization global networks and networks using the services of telecommunications providers (GSM, GPRS, EDGE, 3G, WiMAX, etc.)

Choice of technology for different systems

First, we will briefly dwell on the principles of choosing wireless hardware for the organization of industrial control systems.

Today, the main problem for a user who decides to apply wireless solutions is the choice of the appropriate technology. There are many types of wireless communications and, like wired networks, different systems have different requirements.

The choice of technology should be guided by the following factors:

Data volume: Some consumers need to collect megabits of data per second, others need only turn individual devices on and off several times a day.
Response time: when a device is part of a circuit, receiving a command at a given moment is an essential criterion. The required reaction time can be several microseconds.
Reliability of the response: will the message be received with certainty and, if not, what is the probability of detecting errors? Here, when choosing a technology important role interference is playing.
Communication distance: are the network nodes located in a large area or concentrated in one place? The distance can be from a few meters for moving parts of the mechanism to several kilometers for pumping stations of the distribution network. The covered distance determines the power consumption and often determines whether license-free communication technology can be used.
Number of nodes: Whether communication is required between only two nodes, or many nodes are involved, which will require the use of a more advanced communication structure (Scatternet topology).

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A Brief Overview of Wireless Network Types

Personal wireless networks

IrDA (Infrared Data Association) - communication in the infrared range of light waves
Bluetooth is a short-range radio technology (typically up to 200 meters) in a license-free frequency band (ISM band: 2.4-2.4835 GHz).
UWB (Ultra-Wide Band) is a short-range wireless technology (about 10 meters) that uses the widest frequency range for commercial communication devices.
Wireless USB, wireless USB - designed to replace wired USB.
Wireless HD is a wireless transmission technology primarily for HD video transmission, but it can also be used for wireless networking.
WiGig (IEEE 802.11ad.) is a broadband wireless technology that operates in the unlicensed 60 GHz frequency band and provides data transmission up to 7 Gb / s at a distance of up to 10 meters.
WHDi, Wireless Home Digital Interface (Amimon) is a wireless data transmission technology used for high-speed data transmission and optimized for high-definition video transmission.
LibertyLink is a wireless personal area networking technology developed by Aura. The effect of magnetic induction is used to transmit information.
DECT/GAP - digital advanced wireless telephony system; wireless communication technology used in modern cordless telephones.

Wireless sensor networks

DASH7 is a wireless sensor networking standard. A sensor network is a network of miniature computing devices equipped with touch sensors.
Z-Wave is a wireless radio technology used to organize sensor networks. The main purpose of Z-Wave networks is the remote control of household appliances and various home devices that provide control of lighting, heating and other devices for automating the management of residential buildings and office space.
Insteon is a combined (partly wired and partly wireless) sensor network. To transmit information, a radio signal at a frequency of 902-924 MHz is used, which provides data transmission at a distance of up to 45 meters in line-of-sight conditions at an average speed of 180 bps.
EnOcean is a wireless sensor networking technology using subminiature sensors with power generators, microcontrollers and transceivers.
ISA100.11a is a standard for organizing industrial sensor networks, sensor networks and actuators. For transmission, low-speed wireless communication is used using elements with low power consumption. A distinctive feature of ISA100.11a from other sensor networks: 1) focus on industrial use and, accordingly, specific requirements for strength, noise immunity, reliability and security, 2) the ability to emulate protocols of already existing and proven wired and wireless sensor networks using ISA100.11a technology . Data exchange is carried out at a frequency in the region of 2.4 GHz and a speed of about 250 kbps.
WirelessHART is a wireless communication protocol developed by the HART Communication Foundation for transmitting data as HART messages in a wireless environment. HART is a communication protocol for interacting with field sensors.
MiWi is a protocol for organizing low data rate sensor and personal area networks over short distances based on the IEEE802.15.4 specification for wireless personal area networks.
6LoWPAN is a standard that allows small wireless networks (private networks or sensor networks) to interact with IP networks using the IPv6 protocol.
One-Net is an open protocol for organizing wireless sensor networks and networks for building automation and distributed objects.
Wavenis is a wireless data transmission technology that uses frequencies of 433/868/915 MHz and provides transmission over a distance of up to 1000 m in open space and up to 200 m indoors, at speeds up to 100 Kbps. Wavenis technology is used to organize personal networks and sensor networks, as the ultra-low consumption of transceiver devices allows them to work autonomously for up to 15 years from one battery.
RuBee is a local wireless network that is mainly used as a sensor network. The RuBee uses magnetic waves to transmit data and transmits at a frequency of 131 kHz, which provides a speed of only 1200 baud per second at distances from 1 to 30 meters.

Small local wireless networks

HiperLAN (High Performance Radio LAN) is a wireless communication standard. There are two revisions of the standard: HiperLAN 1 and HiperLAN 2. The HiperLAN 1 standard was released in 1981 and describes a slower communication line that provides data transfer rates up to 10Mbps at a distance of up to 50 meters.
wifi- trademark Wi-Fi Alliance, which is a family of IEEE 802.11 specification standards for broadband radio communications. Depending on the standard, Wi-Fi uses a frequency range around 2.4 GHz or 5 GHz for data transmission and provides data transfer rates from 2 Mbps at distances up to 200 meters.
ZigBee is a technology for organizing wireless sensor and personal networks. ZigBee technology provides low power consumption and data transmission on an unlicensed frequency of 2.4 GHz (for different countries the frequency may differ) at a speed of up to 250 Kb / s, at a distance of up to 75 meters in line-of-sight conditions.
RONJA (Reasonable Optical Near Joint Access) is a technology for wireless data transmission using an optical signal.

Large local area wireless networks

WiMAX (Worldwide Interoperability for Microwave Access) is a wireless data transmission technology based on the IEEE 802.16 standard. The main purpose of the technology is high-speed communication over long distances and providing Internet access.
HiperMAN is a wireless data transmission technology based on the IEEE 802.16 standard. European alternative to WiMAX technology. HiperMAN is specialized in packet data transmission and wireless IP networking.
WiBro (Wireless Broadband) is a wireless technology for high-speed data transmission over long distances based on the IEEE 802.16e standard. North Korean analogue of WiMAX Mobile technology.
Classic WaveLAN is a wireless communication technology used to organize local area networks (a wireless alternative to wired Ethernet and Token Ring networks). Data transfer is carried out in the frequency range of 900 MHz or 2.4 GHz, while providing a transfer rate of up to 2 Mbps.

Manufacturers of hardware for organization of wireless networks ICS

This review will consider some interesting proposals from currently popular manufacturers presenting equipment on the market for:

Industrial process control systems: Phoenix Contact, Siemens, Omron, Moxa
ACS for engineering systems of buildings and structures, "smart home": Thermokon, JUNG

When writing a review, widely used practical experience use of a number of the listed devices.

Phoenix Contact

Phoenix Contact's comprehensive product portfolio and excellent functionality make it an excellent market leader in wireless solutions for industrial automation.

Phoenix Contact supplies components to solve any problem related to the construction of wireless communication systems in industrial environments. Wireless devices are designed for operation in harsh industrial environments, characterized by high reliability, ease and convenience of use, as well as maximum security of data transmission.

Transmission of a small number of signals or huge volumes data, providing real-time communication between devices located close to each other or hundreds of meters away, in industrial premises with metal barriers or in open areas - for these and other requirements, it is possible to select the appropriate components and accessories for them from Phoenix Contact.

Each application has its own requirements for radio communications. Phoenix Contact offers a range of wireless products based on various technologies that make communication tasks flexible, simple and cost-effective.

Each specific application has its own functional and technical requirements for wireless communication technologies. Since currently no existing radio technology can satisfy all requirements, Phoenix Contact offers solutions based on various technologies.

So, what kind of hardware by communication type does Phoenix Contact offer consumers?

Bluetooth I/O (IEEE 802.15.1). The main area of application of Bluetooth technology is the integration of automation system components into local networks fieldbus or Industrial Ethernet. With support for various user profiles, the wireless communication standard can be applied to a wide range of applications. Distinctive features:

A very reliable way to transfer data in production rooms with metal objects.
Possibility of local parallel operation of several Bluetooth networks.
Automatic coexistence mechanisms provide noise-resistant WLAN 802.11b/g parallel operation.
Combining up to seven terminal devices with a radio network.
Bandwidth up to 1 Mbps.
The transmission range is typically over 100m in industrial environments and over 200m in open areas.
Ideal for fast cyclic transmission of small data packets.
Transparent data transmission over Ethernet at the Layer-2 level, eg in PROFINET IO systems.
High data security thanks to 128-bit data encryption and Trusted Wireless endpoint authentication.

Bluetooth I/O is an efficient technology developed by Phoenix Contact for the automation of industrial plants (eg textile, chemical industry) without creating an industrial control system project in relation to building structures. Project creation and system deployment can be done very quickly and there will be no additional requirements for cabling and installation of equipment.

Phoenix Contact Factory Line Bluetooth for wireless transmission of control signals

Among the methods of reliable wireless transmission of data transmission, it is worth noting:

Trusted Wireless- industrial radio technology for transmission of non-delay-critical process signals over long distances - up to several kilometers.

Phoenix Contact Radioline based on Trusted Wireless technology

Wireless MUX- a simple solution for the transmission of digital and analog process and control signals - simply and reliably without cables, from one point to another. Confident and reliable transmission over distances up to several hundred meters.

Phoenix Contact Wireless-MUX Multichannel Wireless System

Wireless I/O - technology for wireless transmission of delay-critical process and control signals in networks automatic systems management. It is characterized by high speed, reliability, simple and convenient maintenance.

High-performance networks are represented by WLAN technology (IEEE 802.11). On the basis of WLAN, it is possible to implement networks that combine many terminal devices. Since WLAN systems can be easily integrated into information networks, they are well suited for mobile management, control and data logging. In addition, it is possible to create a fast communication channel between control devices and transfer input and output data in real time in PROFINET I/O systems. Other features:

The ability to create large networks that combine several hundred end devices
High bandwidth up to 300 Mbps.
Thanks to the automatic roaming function, it is possible to create networks with a large coverage area that provide high mobility.
The transmission range is usually up to 100 m in industrial premises and more than 200 m in open areas. In some cases, the transmission range can be more than 1 km.

The main types of Phoenix Contact equipment that support the listed technologies:

Wireless Ethernet - are used for wireless connection to the Ethernet network of automation system components. Data transmission at the Layer-2 level is carried out in a protocol-transparent mode. Industrial Ethernet protocols such as PROFINET, Modbus/TCP and EtherNet/IP are supported.

Factory Line Bluetooth - Reliable communication components for small wireless LANs operating in parallel.

Factory Line WLAN - components that provide high-speed wireless access to an Ethernet network with a large coverage area.

Factory Line Wireless Serial - devices with a serial interface that can be integrated into an Ethernet network using Factory Line Bluetooth or Factory Line WLAN components.

Reliability

The greatest attention is paid to the reliability and noise immunity of wireless communication channels in harsh industrial environments. Wireless data transmission is carried out by means of electromagnetic waves. In this case, the radio communication channel is affected by external sources of electromagnetic interference.

Strong electromagnetic interference fields generated in industrial premises by various devices, such as frequency converters, as a result of switching loads or the operation of a welding machine, do not affect radio communications, since such electromagnetic interference is within the kilo- or megahertz range, while Bluetooth, Trusted Wireless and WLAN operate in the 2.4 GHz band. Additionally, Bluetooth, Trusted Wireless, and WLAN support spread spectrum signals and other mechanisms to ensure high reliability of data transmission.

Advantages

Undoubtedly, the advantages of this manufacturer include the reliability of ensuring the stability and noise immunity of communication channels due to modern methods of coding and organization of the radio channel. I would like to note the Wireless MUX tools (such as ILB BT ADIO MUX-OMNI) , which allow you to quickly deploy, for example, information-measuring systems and monitoring systems, up to the creation of diagnostic, mobile complexes for temporary use. Efficient automation of moving SCADA objects can be achieved using the Wireless LAN access point, FL WLAN 5100.

Omron

The Japanese company Omron is well known for its innovative approach, the desire to use new technologies to create new systems. This principle is also used by the manufacturer when creating wireless communication solutions. When Omron released the DeviceNet WD30 wireless device, it was widely acclaimed for implementing fieldbus capabilities (previously only available in wired form) for short to medium range wireless communications.

Then Omron released the next modification of the DeviceNet wireless modem - WD30-01. The differences compared to the existing WD30 modem may seem minor, but they significantly expand the scope of these blocks. Now the antennas have a magnetic base and a cable 2 meters long. This allows you to install WD30 units inside the case, taking the antenna out of it, which provides more flexible use of this device.

About the WD30 family

Omron's DeviceNet wireless devices allow you to communicate with any DeviceNet compatible device via a fully wireless fieldbus. The WD30 is more than just a 1:1 network expansion device. One Omron WD30 Wireless Master can access multiple slaves.

A single DeviceNet network can host multiple master wireless devices, forming complex, flexible configurations in a single system.

Technology used

DeviceNet wireless devices combine two of the latest wireless technologies: spread spectrum and antenna diversity. The wireless communication is based on DSSS (Direct Sequence Spread Spectrum) technology with 34 separate channels in the 2.4 GHz band. This frequency has been allocated worldwide for use by industry, science and medicine (ISM). The use of spread spectrum technology reduces the effect of interference, ensuring that the message gets through the first time.

All DeviceNet transceivers use a dual antenna system. It measures the device's output by calculating the difference between the signal and its reflections. The transceiver automatically selects the antenna with best quality signal to reduce interference.

Omron's DeviceNet wireless devices were the first mass-produced wireless devices to combine these technologies.

Wide range of applications

Due to cable characteristics, DeviceNet cable topology requirements typically limit the length of intermediate network links to six meters. However, in some systems it is required to noticeably about Extra cable length. Omron's DeviceNet wireless network now allows data to be transmitted to DeviceNet nodes up to 60 meters from the backbone.

Low output power (10mW) minimizes RF interference in other devices. The high operating frequency reduces the possibility of electrical noise on the factory floor due to interference with DeviceNet wireless devices. DeviceNet wireless devices have an additional built-in security feature that prevents other users from changing parameters without knowing the codes. The setup procedure is to set a specific combination of switch positions that is difficult to repeat. Changing the switch positions does not change the device configuration.

The WD30 master and slave devices are equipped with a standard DeviceNet miniature connector, which expands the possibilities of using DeviceNet in production rooms. These applications include material handling, conveyor systems, assembly lines, robocars, and moving equipment where wires are impractical. DeviceNet wireless devices require a different set of skills, slightly more knowledge, and more intensive training.

Among the advantages of the wireless solutions of this manufacturer, we note the long-term reliable operation of radio modems (DeviceNet networks) in industrial workshops saturated with a variety of interference-generating equipment, such as regulators based on voltage and current cutoff, frequency converters, etc.

Omron DeviceNet WD30-01 Wireless Devices

Siemens

The capabilities of wireless networks are implemented in industrial systems communications (IMC - Industrial Mobile Communication), built on the corresponding SIMATIC NET components, which are based on generally recognized world standards - IEEE 802.11, GSM, GPRS and UMTS.

IMC covers the software and hardware components of SI-MATIC NET, which provide the possibility of data exchange via wireless communication channels of Industrial Ethernet and PROFIBUS networks. SIMATIC NET components can be used to build a communication system for the entire company - from connecting a simple device to a network to organizing intensive data exchange between complex systems. Access points IWLAN (Industrial Wireless Local Area Network) of the SIMATIC NET family are able to communicate with all mobile devices that meet the requirements of IEEE 802.11 a, b, g, h.

SCALANCE W family

The SCALANCE W family combines a number of communication modules designed to build highly reliable IWLANs with deterministic data transfer time and support for redundant communication channels.

Such wireless networks allow both time-critical messages (for example, IWLAN with emergency messages) and regular messages (for example, WLAN with service and diagnostic messages) to be transmitted through their channels. In general, such networks in terms of their functionality overlap the requirements of the IEEE 802.11 standard.

SCALANCE W modules are produced in rugged metal cases with IP65 degree of protection, providing reliable protection against moisture and dust and the ability to use the modules in vibration and shaking conditions.

All modules of the SCALANCE W series support standard user identification mechanisms that protect the IWLAN from unauthorized access, as well as mechanisms for encoding transmitted data.

Industrial version

SCALANCE W modules are able to maintain their performance in the temperature range from -20°C to +60°C, to be exposed to moisture and dust for a long time. The antennas, power supplies and connecting cables used in them are also oriented to operation in industrial conditions.

IWLAN Use Cases

Wireless integration of PROFIBUS and PROFINET segments of stations into an existing Industrial Ethernet network is possible. To do this, the required number of SCALANCE W access points is connected to the fixed Industrial Ethernet network.

Access points can be equipped with circular or directional antennas, as well as extended low-radiation antennas in the form of an RCoax cable. Through access points, any stationary or mobile objects equipped with client modules or IWLAN / PB Link PNIO modules can be included in the wireless communication system.

Let us give an example of the implementation of remote configuration of equipment at mobile stations. Mobile stations move freely within the radio coverage area formed by two SCALANCE W788-1PRO access points. Each mobile station is equipped with a SCALANCE W746-1PRO client module. Provides support for wireless communication of the operator panel, computer and programmable controller of each mobile station with the controller and the human-machine interface system of the fixed Industrial Ethernet network. The Field PG M programmer is used for remote maintenance of all equipment in this system.

In the radio coverage area of one SCALANCE W788-1PRO or SCALANCE W788-2PRO access point, mobile stations with PROFINET IO distributed I/O system components can operate.

Software

The SINEMA E software package with a standard license provides support for the functions of automatic positioning of infrastructure components and optimization of communication channels, determines the necessary types of access points, and optimizes the values of their settings.

Supported products:

WLAN access points: SCALANCE W788; W786; W784; HiPath AP2610, 2620, 2630, 2640; access points via Wi-Fi 802.11 a/b/g/h.
WLAN client modules: SCALANCE W744; W746; W747; IWLAN/PB Link PNIO; client modules via Wi-Fi 802.11 a/b/g/h.
LAN/WLAN adapters to support read/download functions: SIMATIC NET CP 1613 A2; CP 1612; standard LAN adapter; standard WLAN card.
WLAN adapter for WLAN measurements; for measurements in standard mode - a standard WLAN adapter; for advanced measurement mode - PCMCIA WLAN adapter.

One of the advantages of this manufacturer is the offer of wireless device kits that are compatible with the most popular Siemens PLCs and systems in the industry, providing noise-resistant and reliable communication for process control systems in various industries, including transport.

Access point Siemens SKALANCE W788-1PRO

Moxa

Moxa has developed and manufactures a wide range of solutions for connecting various industrial devices with interfaces based on wireless technologies - IEEE 802.11 (WLAN) and GSM/GPRS/UMTS/HSDPA. Consider equipment for organizing direct, local networks without the participation of telecommunications providers (GSM, GPRS).

RISC computers with wireless interfaces

Moxa ThinkCore Embedded Computers are based on the RISC platform and are designed to create custom applications for industrial automation. They have a software selectable RS-232/422/485 serial port, 802.11a/b/g WLAN interface, SD slot, 2 USB and 1 Ethernet port. Moxa ART, 32-bit ARM9 processor, and embedded Linux OS provide a powerful and reliable platform for harsh industrial environments, as well as a successful solution for industrial M2M applications: data exchange, protocol conversion, and remote device control and verification.

The following models are supplied to Ukraine: Moxa ThinkCore W311 (RISC-based embedded computer with WLAN, 1 serial port, LAN, Linux OS); Moxa ThinkCore W321 (RISC computer with WLAN, 2 serial ports, LAN, SD and Linux OS). Moxa ThinkCore W341 (RISC computer with WLAN, 4 serial ports, LAN, SD, USB, relay outputs, Linux OS).

RISC computers with multifunctional wireless interfaces

The Moxa ThinkCore W311 UC-8481 series computers have 2 RS-232/422/485 serial ports, 2 Ethernet ports, 4 digital inputs and outputs, a CompactFlash socket, and 2 USB 2.0 ports. Moxa ThinkCore W311 UC-8481 is based on the Intel XScale IXP435 533 MHz RISC processor. The computer has great computing and communication capabilities with very little heat generation.

Moxa ThinkCore W311 UC-8481 has seven connectors, which allows users to connect various wireless modules and GPS - this is very important, for example, for applications on the railway and in general, on moving vehicles. Moxa also offers an extended operating temperature model, from -25°C to 70°C, for harsh industrial environments.

Embedded computer Moxa ThinkCore W311 UC-8481

Wireless access controllers

The WAC-1001 industrial wireless controllers are equipped with Moxa Turbo Roaming technology, which dramatically reduces wireless device roaming time to 50ms. This advanced feature ensures high switching speed and seamless connection, without interruptions and security breaches of wireless communications, even in extremely difficult environments. The devices also feature support for IEEE802.11i (wireless security) and a wide operating temperature range of -40°C to 75°C.

Wireless Access Points (AP/Bridge/AP Client)

Moxa offers a large number of such devices. A typical example is Moxa AWK-4131, an industrial 3-in-1 wireless access point (Access Point/Bridge/Client), which allows users to provide high-speed, efficient wireless access to network resources using IEEE 802.11n technology with a network speed of up to 300 Mbps. Moxa AWK-4131 uses two adjacent 20 MHz channels, combining them into one 40 MHz channel - for greater reliability and high throughput. The operating temperature range of the device is -40°C to 75°C.

The Moxa AWK-4131 has a dual power input to improve equipment reliability, and can also be powered over Ethernet (PoE). High-frequency modules Moxa AWK-4131 provide operation in two frequency bands 2.4 and 5 GHz. Moxa AWK-4131 are backwards compatible with IEEE 802.11a/b/g standards, making it easy to integrate them into existing infrastructure. IP68-rated housing and special M12 connectors protect the device from critical environmental conditions (dust, moisture)

IEEE 802.11 Wireless Access Devices (WLAN)

A typical representative of this group of equipment is new series MiiNePort W1 devices (Network Enabler) - Serial-Ethernet access server modules supporting IEEE 802.11 b/g wireless networks. They make it very easy to connect serial devices to wireless networks.

Moxa MiiNePort W1 provides speeds up to 921.6 Kbps over the serial port and supports a large number of different operating modes: RealCOM, TCP Server, TCP Client, UDP, RFC2217, as well as Infrastructure Mode (b/g) and Ad-Hoc Mode (b/g ) for IEEE 802.11 b/g wireless networks. High-quality driver support for Moxa MiiNePort W1 makes it easy to integrate modules into existing solutions.

Moxa MiiNePort W1 has a very compact size: 44.4 x 44.4 x 9.7 mm, as well as extremely low consumption (360 mA for 3.3 VDC, 290 mA for 5 VDC), which allows it to be easily integrated into various serial devices for connecting them to wireless networks.

Moxa MiiNePort W1 Serial-Ethernet Access Device

WLAN antennas

Moxa offers wide selection antennas in various frequency bands (2.4; 5 GHz) and radiation patterns, from circular to directional. Gain ranges: 5 to 18 dBi.

Wireless equipment from Moxa is widely used in the creation automated systems technical accounting, distributed systems for monitoring and measuring technological parameters in the food, paper, chemical industries, mechanical engineering, etc.

Moxa devices perform well in building branched, locally distributed information-measuring and dispatching systems, which is one of their key advantages.

You can read about the means of wireless data transmission in building automation systems in the 2nd part of the review, which will be published in July.

Wireless data transmission, in which signals are transmitted through the air or space without any physical restrictions, is becoming a popular alternative to physical transmission channels such as twisted pair, coaxial or fiber optic cable. At present, common technologies for wireless data transmission include microwave transmission, communication satellites, pagers, cellular telephones, personal communications services (PCS), smart phones, personal digital assistants (PDAs), and mobile data networks.

The means of wireless transmission is the spectrum of electromagnetic waves shown in Fig. 8.3. Some types of wireless transmission, such as microwaves or infrared waves, occupy specific spectral frequency bands, measured in megahertz (MHz). Other types of wireless transmission are now widely used (eg cellular phones or pagers), so in this case, a specific frequency band is allocated, provided by national regulatory agencies, which is governed by international agreements. Each frequency range has its own advantages and disadvantages, making it easier to choose the area of its application.

microwave systems, both ground and airborne, transmit high-frequency radio signals through the atmosphere and are widely used to transmit large amounts of data over great distances, from one point to another. Microwave signals travel in a straight line and cannot bend around the curvature of the Earth; therefore, long distance terrestrial transmission systems require transmission stations to be located 25 to 30 miles apart, making them more expensive.

This problem can be solved by reflecting microwave signals from satellites, which serve as relay stations for microwave signals transmitted from ground stations. Communication satellites are effective (provide minimal overhead) in transmitting a huge amount of information over very long distances. Satellites are commonly used to communicate within large, geographically dispersed organizations where communication via cable systems or microwave ground stations is difficult. For example, Amoco uses satellites to transmit data containing offshore oil exploration results in real time. Research ships transmit the collected data using geosynchronous (geostationary) satellites to central computer centers in the USA for the purpose of their further

most used by researchers in Houston, Toolse, and the Chicago suburbs. On fig. 8.4 illustrates the principles of operation of this system.

Ordinary communications satellites move in stationary orbits about 22,000 miles from the Earth's surface. Recently, the latest satellite systems, the so-called low-orbit satellites, have been launched. These satellites are much closer to the Earth and are able to pick up signals from low power transmitters. These satellites also use less power and are cheaper to launch than geostationary satellites. With such wireless networks, business people will be able to travel throughout the world and have access to rich communication options, including video conferencing and Internet access.

Other wireless transmission technologies are used in situations requiring remote access to corporate systems and mobile computing power. Paging systems have been around for decades, initially only by beeping when a user, receiving a message, had to call the office back to inquire about the content of the message itself.

Microwave (microwaves / radio waves)

The transmission of large amounts of information over long distances from point to point by transmitting high-frequency radio signals through the atmosphere from one ground station to another.

Satellite (satellite channel)

Data transmission using orbiting satellites that serve as relay stations for transmitting microwave signals over very long distances.

Paging system (paging system)

A wireless transmission technology that allows pagers to receive radio signals accompanied by an appropriate sound when a message is received; used to send short alphanumeric messages.

messages. Currently, paging devices can send and receive short alphanumeric messages that the user reads on the pager screen. Paging is useful for communicating with mobile workers such as maintenance crews; one-way paging can also provide an inexpensive way to communicate with workers in offices. For example, Computer Associates distributes two-way pagers equipped with Unicenter CA control software, which allow computer network operators to control the situation, as well as quickly respond to emerging problems.

Cell Phones operate by transmitting/receiving radio waves to communicate with base stations located within contiguous geographic areas, called cells. The telephone signal is transmitted to the local cell, then it is transmitted from station to station (cell to cell) until it reaches the target cell, after which it is transmitted to the receiving phone. As the cellular signal travels from one cell to another, the computer that

Cellular telephone (cell phone)

Personal communication services (PCS) (personal communication services)

Digital cellular technology that uses lower power, higher frequency radio waves than analog cellular technology.

Smart phone (smart phone)

A cordless phone that offers voice, text, and Internet connectivity.

The first monitors the signals from the cells, selects the radio channel assigned to the next cell. The size of the hexagonal honeycomb is usually up to eight miles, although it may decrease in densely populated areas.

Older cellular systems are analog and newer cellular systems are digital. Personal communications services (PCS) are a popular type of digital cellular service. The PCS service is completely digital. It provides voice and data transmission, and uses a higher frequency range than analog cellular phones. PCS cells are much smaller and more closely spaced than analog cells and can carry more traffic. In addition to voice communications, newer models of digital cellular telephones can handle voicemail, email, and faxes; save addresses; provide access to private corporate networks and also to the Internet. These smart phones are equipped with web browsers, which allow access to web pages containing text or other information (without graphics), which is convenient for devices equipped with small screens. Some smart phones are equipped with large screens as well as additional keyboards to make it easier to access the Internet. In ch. 9 discusses in detail the use of these devices to provide wireless access to the Internet.

Personal digital assistants (PDAs) are small, touch-screen, portable computers capable of fully digital data transmission. PDAs have built-in wireless telecommunications capabilities as well as organizer software. A well-known example is the Palm VII plug-in organizer. This device allows you to exchange messages Email and also provides access to the Internet. Applications such as an electronic planner, address book, and financial organizer are also supported. The device can accept data entered using a touchscreen stylus. The Organizational Window describes Safeway U.K. using a PDA in an e-commerce app to shop at a grocery store.

Personal digital assistants (PDA) (PDAs)

Small, touch-screen, portable computers with built-in digital telecommunications capabilities.

Mobile data networks (mobile data networks)

Wireless networks that carry out two-way transfer of data files cheaply and efficiently.

Wireless networks specially designed for the two-way transfer of data files are called mobile data networks. These radio wave based networks transmit data generated by laptop computers. Another type of mobile data network is based on a series of transmitters built specifically for text and data transmission. Net Ardis(which owns American Mobile Satellite Corp.) is a public network that uses the described features to organize two-way data transmission on a national scale. Company Otis Elevators uses the network Ardis to manage the movement of specialists in maintenance throughout the country, located in an office located in the state of Connecticut. Experts use this network to send out reports.

Wireless networks and transmission devices are more expensive, slower, and more prone to errors than conventional LANs (Varshney and Vetter, 2000). However, major digital cellular networks are constantly increasing their data rates (Chapter 9). (Owners of satellite systems such as Teledesic spend billions to deliver huge data rates over wireless networks associated with multimedia applications.) Ensuring optimal throughput and power consumption in wireless devices requires careful management, both technically and software(Imielinski and Badrinath, 1994). Due to the fact that the radio signal can be easily intercepted, it is difficult to ensure security and secrecy (chap. 14),

Data cannot be transmitted in a consistent manner between different wireless networks if they use incompatible standards. For example, digital cellular service in the United States is supported by different operators using one of several competing digital cellular technologies (CDMA, GSM 1900, and TDMA IS-136) that are not compatible with each other. Many digital cellular handheld receivers that use one of these technologies cannot operate in countries outside of North America and operate on different frequencies with different sets of standards. A detailed discussion of these standards, as well as other network standards, is given in Chap. 9.

Wireless technologies are used to transmit information over a distance between two or more points without requiring their connection by wires. To transmit information, infrared radiation, radio waves, optical or laser radiation can be used.

Currently, there are many wireless technologies, most commonly known to users by their marketing names such as Wi-Fi, WiMAX, Bluetooth. Each technology has certain characteristics that determine its scope.

There are various approaches to the classification of wireless technologies.

Range classification:

Wireless personal area networks WPAN (Wireless Personal Area Networks). These networks include Bluetooth.
WLANs (Wireless Local Area Networks). These networks include Wi-Fi networks.
WMAN (Wireless Metropolitan Area Networks) city-wide wireless networks. Examples of technologies - WiMAX.

Classification by applicationYu:

Corporate (departmental) wireless networks - created by companies for their own needs.
Carrier wireless networks - created by telecom operators for paid provision services.

A short but concise way to classify is to display two of the most significant characteristics of wireless technologies simultaneously on two axes: maximum speed transmission of information and maximum distance.

A brief overview of the most popular wireless technologies

Wi-fi

Developed by the Wi-Fi Alliance consortium based on IEEE 802.11 standards, "Wi-Fi" is a trademark of "Wi-Fi Alliance". The name of the technology is Wireless-Fidelity ("wireless precision") by analogy with Hi-Fi.

At the beginning of use, the installation of Wireless LAN was recommended where the deployment of a cable system was not possible or not economically feasible. At the moment, many organizations use Wi-Fi, as under certain conditions the speed of the network already exceeds 100 Mbps. Users can move between access points within the Wi-Fi coverage area.

Mobile devices (PDAs, smartphones, PSPs and laptops) equipped with client Wi-Fi transceivers can connect to a local network and access the Internet through access points or hot spots.

Story

Wi-Fi was created in 1991 by NCR Corporation/AT&T (later Lucent Technologies and Agere Systems) in Nieuwegein, the Netherlands. Products originally intended for systems cash service, were introduced to the market under the WaveLAN brand and provided data transfer rates from 1 to 2 Mbps. Wi-Fi creator - Vic Hayes ( Vic Hayes) served on a team that contributed to the development of the IEEE 802.11b, IEEE_802.11a, and IEEE_802.11g standards. The IEEE 802.11n standard was approved on September 11, 2009. Its use allows you to increase the data transfer speed by almost four times compared to 802.11g devices (the maximum speed of which is 54 Mbps), when used in 802.11n mode with other 802.11n devices. Theoretically, 802.11n is capable of providing data transfer rates up to 480 Mbps.

Bluetooth

Bluetooth is an industrial specification for wireless personal area networks. Wireless personal area network, WPAN).

The Bluetooth specification was developed by the Bluetooth Special Interest Group, which was founded in 1998. It includes Ericsson, IBM, Intel, Toshiba and Nokia. Subsequently, the Bluetooth SIG and the IEEE reached an agreement whereby the Bluetooth specification became part of the IEEE 802.15.1 standard (published on June 14, 2002). Ericsson Mobile Communication began work on the creation of Bluetooth in 1994. Initially, this technology was adapted to the needs of the FLYWAY system in a functional interface between travelers and the system.

The Bluetooth range can reach up to 100 meters.

WiMAX (English) worldwide I interoperability for Microwave Access) is a telecommunications technology designed to provide universal wireless communication over long distances for a wide range of devices (from workstations and laptops to mobile phones). The technology is based on the IEEE 802.16 standard, also called Wireless MAN.

Scope of use

WiMAX is designed to solve the following problems:

· Connecting Wi-Fi hotspots to each other and other segments of the Internet.

Providing wireless broadband access as alternatives to leased lines and DSL.

· Provision of high-speed data transmission and telecommunication services.

Creation of access points that are not tied to a geographic location.

WiMAX allows you to access the Internet at high speeds, with much greater coverage than Wi-Fi networks. This allows the technology to be used as “backbone channels”, which are continued by traditional DSL and leased lines, as well as local networks. As a result, this approach allows you to create scalable high-speed networks within entire cities.

WiMAX Standards Specifications

IEEE 802.16-2004 (also known as 802.16d or Fixed WiMAX). The specification was approved in 2004. Supports fixed access in areas with or without line of sight. User Devices: Fixed indoor and outdoor modems, and PCMCIA cards for laptops. In most countries, the 3.5 and 5 GHz bands are reserved for this technology. According to the WiMAX Forum, there are already about 175 implementations of the fixed version. Many analysts see it as a competing or complementary DSL wired broadband technology.

IEEE 802.16-2005 (also known as 802.16e and mobile WiMAX). The specification was approved in 2005 and is optimized to support mobile users and supports a number of specific features such as handover, idle mode and roaming. Planned frequency bands for mobile networks WiMAX are: 2.3-2.5; 2.5-2.7; 3.4-3.8 GHz. Several pilot projects have been implemented in the world, including Skartel, the first in Russia to deploy its network. Competitors to 802.16e are all third generation mobile technologies (eg EV-DO, HSDPA).

The main difference between the two technologies is that fixed WiMAX allows serving only “static” subscribers, while mobile WiMAX is focused on working with users moving at speeds up to 120 km/h. Mobility means the presence of roaming functions and "seamless" switching between base stations when the subscriber moves (as happens in cellular networks). In a particular case, mobile WiMAX can also be used to serve fixed users.

There are various approaches to the classification of wireless technologies.

Range classification:

Wireless personal area networks WPAN (Wireless Personal Area Networks). These networks include Bluetooth.
WLANs (Wireless Local Area Networks). These networks include Wi-Fi networks.
WMAN (Wireless Metropolitan Area Networks) city-wide wireless networks. Examples of technologies - WiMAX.

Classification by applicationYu:

Corporate (departmental) wireless networks - created by companies for their own needs.
Operator wireless networks - created by telecom operators for paid provision of services.

A short but concise way to classify is to simultaneously display the two most significant characteristics of wireless technologies on two axes: maximum information transfer rate and maximum distance.

A brief overview of the most popular wireless technologies

Wi-fi

Mobile devices (PDAs, smartphones, PSPs and laptops) equipped with client Wi-Fi transceivers can connect to a local network and access the Internet through access points or hot spots.

Story

Wi-Fi was created in 1991 by NCR Corporation/AT&T (later Lucent Technologies and Agere Systems) in Nieuwegein, the Netherlands. Products originally intended for POS systems were introduced to the market under the WaveLAN brand and provided data transfer rates from 1 to 2 Mbps. Wi-Fi creator - Vic Hayes ( Vic Hayes) served on a team that contributed to the development of the IEEE 802.11b, IEEE_802.11a, and IEEE_802.11g standards. The IEEE 802.11n standard was approved on September 11, 2009. Its use allows you to increase the data transfer speed by almost four times compared to 802.11g devices (the maximum speed of which is 54 Mbps), when used in 802.11n mode with other 802.11n devices. Theoretically, 802.11n is capable of providing data transfer rates up to 480 Mbps.

Bluetooth

Bluetooth is an industrial specification for wireless personal area networks. Wireless personal area network, WPAN).

The Bluetooth range can reach up to 100 meters.

WiMAX (English) worldwide I interoperability for Microwave Access) is a telecommunications technology developed to provide universal wireless communication over long distances for a wide range of devices (from workstations and laptop computers to mobile phones). The technology is based on the IEEE 802.16 standard, also called Wireless MAN.

Scope of use

WiMAX is designed to solve the following problems:

· Connecting Wi-Fi hotspots to each other and other segments of the Internet.

· Provision of wireless broadband access as an alternative to leased lines and DSL.

· Provision of high-speed data transmission and telecommunication services.

Creation of access points that are not tied to a geographic location.

WiMAX Standards Specifications

IEEE 802.16-2005 (also known as 802.16e and mobile WiMAX). The specification was approved in 2005 and is optimized to support mobile users and supports a number of specific features such as handover, idle mode and roaming. Planned frequency ranges for Mobile WiMAX networks are as follows: 2.3-2.5; 2.5-2.7; 3.4-3.8 GHz. Several pilot projects have been implemented in the world, including Skartel, the first in Russia to deploy its network. Competitors to 802.16e are all third generation mobile technologies (eg EV-DO, HSDPA).

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