Network and Wireless Communication Solutions

Wireless communication has become an indispensable part of our lives. We all connect to the internet wirelessly with WiFi, listen to music with bluetooth wireless headphones, and log in to school / workplace by having our ID card read. These are all examples of wireless communication, but how are they different from each other?

Wireless communication, as the name suggests, is the name given to data transmission without any cables. Generally, radio waves are used for data transfer. The reason I usually say is because technologies that use light instead of radio waves, such as infrared, are still in our lives. The remote controls of devices such as televisions we use in our home communicate with infrared light. If we recall, the mobile phones we used in the 2000s could even transfer files with infrared communication instead of bluetooth.

Examples of wireless devices are mobile phones, GPS devices, the controls we use to open parking barriers, and the cards we use as tickets in buses. If you have noticed, some of these devices act only as a receiver, some as a transmitter and some as both a receiver and a transmitter. Almost all of them use different communication protocols. We can also use some of these communication systems such as WiFi, Bluetooth and NFC in our own projects. I will try to talk about their working principles and differences as much as I know.

WiFi

This abbreviation, which we can translate into Turkish as a wireless local area network, consists of the first two letters of the words Wireless Fidelity. It operates at 2.4 GHz and 5 GHz frequencies. All devices using IEEE 802.11 standards can be defined as WiFi devices. Internet connection can be used for home or office network and communication between two devices.

WiFi devices basically have 3 different operating modes: Infrastructure (infrastructure) and Ad-Hoc (direct communication between two devices). Infrastructure mode has two different sub-modes: client and station. As a client, we can give our computers, mobile phones and WiFi modules that we can use in our projects. Station devices are modems and routers. Most devices can be used interchangeably between client and station modes. For example, when we turn on the wireless access point in our smartphone, the WiFi module of our phone exits the client mode and enters the station mode and puts the mobile internet on the air using its own WiFi module.

In Ad-Hoc connection, two devices can only communicate with each other. In this case, both devices act as both clients and stations.

The most used IEEE 802.11 standards today are 802.11b / g / n and ac standards.

The 802.11b and 802.11g standards use the 2.4 GHz frequency. The maximum communication speeds they can reach are 11 Mbps for the 802.11b standard and 54 Mbps for the 802.11g standard.
The 802.11n standard uses 2.4 GHz and 5 GHz frequencies. The maximum speed that can be reached using this standard is 150 Mbps.
The 802.11ac standard uses the 5 GHz frequency. The maximum speed that can be reached using this standard is 780 Mbps.
Bluetooth

It is a technology developed for data transfer over short distances. It was developed by Ericsson in 1994 to be a wireless alternative to RS-232 connection when it was first released. It operates at a frequency of 2.4 GHz. It is used in applications such as file transfer, audio transfer and virtual COM port. The communication protocol is constantly being developed and updated. As current devices support new protocols, backward compatibility is also available.

The speeds in Bluetooth communication are as follows:

Bluetooth v1.2: 1 Mbps
Bluetooth v2.0 + EDR: 3 Mbps
Bluetooth v3.0 + HS: 24 Mbps
Bluetooth v4.0: 24 Mbps
Today, devices such as smart watches that are aimed to consume less power use the protocol named Bluetooth Low Energy. This protocol is only compatible with Bluetooth v4.0 and BLE supporting devices, not backward compatible.

NFC and RFID

NFC is often confused with RFID. RFID, in general, is the name given to the technology used to identify objects using radio waves. It has active and passive tags. Active tags contain their own power supply and thus enable communication from greater distances. Passive tags work by being fed by the magnetic field generated during reading. OGS and HGS systems used in bridge and highway toll booths can be given as the best examples of active and passive tags. While OGS is a large device that contains a battery inside the device, the HGS is in the form of a card or tag. There are RFID tags operating in three different frequency bands:

Low Frequency (LF) 125 -134 kHz
High Frequency (HF) 13.56 MHz
Ultra High Frequency (UHF) 856 MHz to 960 MHz
NFC is a wireless communication that works by touching or bringing devices closer together at short distances such as 10 cm. 

technology. NFC is an application of RFID technology. It operates in the HF band (13.56 MHz).

NFC devices can operate in three different modes: NFC card emulation mode, printer / reader mode, and peer-to-peer mode. In card emulation mode, devices such as smartphones act as a card to make payments for shopping, etc. It can be used in different ways. In the writer / reader mode, the NFC device can be used to read and write an NFC card or tag. In peer-to-peer mode, protocols such as file transfer between two NFC devices are initiated using NFC.

NFC cards have a small amount of memory. This memory can only be read or rewritable.

Other Wireless Communication Standards

There are many different communication devices and protocols other than WiFi, Bluetooth, RFID and NFC, which are the most common in wireless communication. I'm sure those interested in development platforms like Arduino have heard of names like XBee and ZigBee. Wireless modules like this one can have different protocols of their own, operate unidirectional or bidirectional, have different ranges, and operate at different speeds. Detailed information on these is mostly provided by the manufacturers.

Network Systems

The network is the most economical and efficient use of many communication equipment such as servers, printers, computers and modems connected by cables. The network allows people to work together, not individually.

Networking is the sharing of data, software and equipment. A small network can consist of two computers, while a large network can consist of thousands of computers, fax-modems, cd-rom drives, printers, and so on.

Why Network is needed?

The network saves time and money. For success, the business must communicate not only in the office, but with the whole world. As sharing is in question, the hardware can be used by all personnel, no extra printer, modem, disk unit is required for each individual. Internet access can also be shared on a network.

How Does the Network Work?

Ethernet is the most common network system. It came with the Ethernet Standards. All messages sent over the Ethernet network consist of standard codes that other equipment can receive. It was first discovered by XEROX and then formulated by DEC, Intel and XEROX and emerged as a system that can transfer 10 Mbit data per second using certain methods.