Wireless Communication

Wireless Communication

4. Industrial Revolution (or Industry 4.0 as used today) has created new business models, in which every living or non-living object will be connected to internet to communicate, and the smart communication between machines bring intelligent production. The basis of the concept of Industry 4.0 is that all units related to industrial production communicate with each other, access all data in real time, and the use of these data stacks by users and the internet whenever they want (cloud computing). This not only increases efficiency but also reduces costs.

The Most Important Building Block of Industry 4.0: Internet of Things (IoT):

With the interconnection of objects, people and cloud services over internet, new areas of use and business models are emerging. Today, more and more products are becoming intelligent thanks to the MCUs (micro control units), and with the spread of WiFi and internet access, tablets, computers and smartphones are becoming available as gateways. With the spread of IoT applications, all business models are starting to be reshaped. IoT is now widely used in smart homes, building automation systems, smart cities, smart manufacturing processes, wearable products and healthcare services. While it is estimated that 20 billion devices will be connected to the Internet by 2020 with Industry 4.0, it reveals the fact of how important wireless communication is in these applications.

Wireless Communication

With wireless communication, you can communicate via your computers, mobile phones and many other devices without the need for cables. This is a flexible mobile communication system that transmits data through the air via electronic magnetic waves. Such communications are realized over specific networks. The most widely used networks in wireless communication are:
● OSI, TCP/IP, IEEE, Standards
● PAN, LAN, MAN, WAN, WLAN, SAN structures
● Cable (Coaxial, STP, UTP, Fiber) structures
● Topologies (Bus, Star, Ring, exStar)
● TCP/IP(dhcp, http, ftp, snmp, smtp) protocols
● IPv4, IPv6, Subnet, addresses
● Repeater, Hub, Bridge, Switch, Router network devices and configurations

Wireless Communication Technologies

– InfraRed
– Bluetooth
– HomeRF
– HiperLan
– WLan
– Wi-Fi
– WiMax
– GSM
– GPRS

Infrared (IrDA)

● Infrared Data Association
● Infrared (IR) radiation is the electromagnetic radiation whose wavelength is longer than visible light but shorter than Terahertz radiation and microwaves.
● The wavelength of infrared radiation
it is between 750 nanometers and 1 micrometer.
● Infrared radiation can be classified into three different groups. These are: Near-infrared (NIR), mid-infrared (MIR) and far-infrared (FIR) radiations.
● Of the sunlight, 47% is infrared,
46% is visible light and 7% is ultraviolet radiation.

Wi-Fi

● Wireless network ports actually work in the same way as the router modems and produce small radio waves. The Wi-Fi standards are divided as
802.11a,b,g and n according to their types and characteristics. Of these, the most widely used is 802.11b and has a spread range of 2.4Ghz. However, with 802.11b it is possible to establish a connection of up to 11 Megabits. On the other hand, it is possible to reach speeds of 54 Mbit per second with 802.11g and 140 Mbit with 802.11N. Today, almost all laptops are equipped with integrated Wi-Fi receivers. Those who are not, on the other hand, can easily be equipped with PCMCIA cards for this purpose.
● This allows the laptops, PDAs and other portable devices to connect to internet via the wireless access points near them.
● The connection is established over the radio frequency, based on the IEEE 802.11 protocol that is jointly supported by the device and wireless access points.

Bluetooth

● It is the term for short distance radio frequency (RF) technology, which eliminates the cable connection.
● Bluetooth allows computers, peripherals, and other devices to communicate with each other even when they are out of range, without a cable connection.
● It is a wireless data transfer technology, which provides digital voice and data transmission over the 2.4GHz ISM band.
● With the frequency hopping called “FHSS”, it is used to block the electrical interference caused by Bluetooth technology and to communicate with many units concurrently. For this reason, Bluetooth devices communicate with each other from 2.4 GHz to 2.48GHz with one Mhz bands each.

WLan

● Wireless Local Area Network (WLAN) is a terrestrial communication method, which is used as an alternative to cable communication, allows for information exchange by using RF (radio frequency), and transfers the intended radio signals in a specific frequency channel.
● It is the wireless conversion of physical and data bound (Layer 1 and Layer 2) layers.
● IEEE defined the 802.11 standard in 1997, which is deemed as the beginning of Ethernet.

HomeRF

● It is a wireless access standard for small offices or home applications.
● It was developed by the HomeRF working group in 1998.
● This working group consisted of more than 100 mobile wireless companies, including Siemens, Motorola and Philips.

HiperLan

● High Performance Radio LAN
● It is a standard designed by the unit of Hyperlan/2 (ETSI) (BRAN) and accepted by ETSI, which is currently applicable in Europe.
● It supports a maximum data transfer rate of 54 Mbps.
● This frequency band can be used without a license in most of Europe. ETSI; European Telecommunications Standard Institute BRAN; Broadband Radio Access Networks.

Wimax

● Worldwide Interoperability for
Microwave Access
● It is a certification mark for instruments using IEEE 802.16 standards. It is applied for wireless high-speed internet access.
● WiMAX offers wireless high-speed
connection of up to a 35-mile (~50-km) distance.
● This technology is intended for regional broadband internet.

“With the spread of IoT applications, all business models are starting to be reshaped.”

Methods of Wireless Communication

Signal – Modulation – Frequency – Radio Frequency – Transceiver – Antenna, Distance – Propagation

The Basics of Wireless Communication

● Signal (Audio signal) is the form of any sound converted into electromagnetic energy for transmission or storage. (It is the electrical form of sound.)

Analog Signal

● The analog signal consists of the sum of sine waves whose amplitudes and frequencies are different.
● Frequency is the number of vibrations per second. Its opposite is the period. In other words, the period is the duration of a single vibration.
Since the analog signal consists of a large number of frequency combinations, it is difficult to process the signal in the time domain. For this reason, it is processed in the frequency domain.
● The number of rotations per second is called frequency and is referred to as Hertz in communication terminology.
● Data is sent using different frequencies while being transferred over a line.
● The frequency range in which the signal starts and ends in the frequency spectrum gives the “bandwidth”.

The main characteristics that determine the signal are the amplitude frequency, phase and bandwidth. An analog signal is a signal whose amplitude changes over time depending on frequency and phase.

Modulation

Modulation is the process of superimposing low-frequency information signals on high-frequency carrier signals and sending them over long distances. (It is to combine an information signal with a carrier signal) (Continuous wave modulation: A method with an RF carrier sine signal)

● Amplitude Modulation (AM)

● Phase Modulation (PM) – The information signal waveform that modulates Frequency Modulation (FM).