Wireless communication is one of the most desired modes of communication (connectivity) between two or more devices. In this technology, the data communication is performed and delivered over the air via electromagnetic waves, such as radio frequencies, infrared and satellite, rather than over cables and wires.
Wireless communications operate over particular frequencies in the electromagnetic spectrum from 3 Hz to 3000 GHz (3 THz), called radio waves. It includes a diverse variety of computing and communications applications ranging from third- to fifth-generation (3G/4G/5G) cellular devices, broadband access, indoor WiFi networks, vehicle-to-vehicle (V2V) systems to embedded sensor and radio frequency identification (RFID) applications, microwave, aeronautical, maritime and other commercial and private radio services.
Due to the dynamic requirement of wireless requirement different methods and standards of wireless communication have been developed across the world, based on various commercially driven requirements like specific application and transmission range. These technologies can roughly be classified into four individual categories; Wireless Personal Area Network (WPAN), Wireless Local Area Network (WLAN), Wireless Metropolitan Area Network (WMAN), Wireless Wide Area Network (WWAN). As implicated by their names, the properties of these solutions in terms of range and data rate are optimized for personal, local, metropolitan, or worldwide coverage and use.
The reach of a Wireless PAN is typically a few meters. WPAN’s can be used for communication among the personal devices themselves (intrapersonal communication), or for connecting to a higher level network and the Internet. A Wireless LAN links the two or more computers without using wires, WLAN utilizes spread-spectrum technology based on radio waves to enable communication between devices IEEE 802.11, the Wi-Fi standard, denotes a set of Wireless LAN/WLAN standards. The Wireless MAN is the name trademarked by the IEEE 802.16 Working Group on Broadband Wireless Access Standards for its wireless metropolitan area network standard (commercially known as WiMAX), which defines broadband Internet access from fixed or mobile devices via antennas. The Wireless WAN is a computer network covering a broad geographical area, WAN’s are used to connect Local Area Networks (LAN’s or WLAN’s) together, so that users and computers in one location can communicate with users and computers in other locations, WAN’s also refer to Mobile Data Communications, such as GSM, GPRS and 3G. The largest and most well-known example of a WAN is the Internet.
RFID (Radio Frequency Identification) can be defined as automatic identification technology, which uses radio-frequency electromagnetic fields to identify objects carrying tags when they come close to a reader. RFID technology is a simple method of exchanging data between two entities namely a reader/writer and a tag. This communication allows information about the tag or the element carrying the tag to be determined and in this way it enables processes to be managed more easily.
The use of RFID technology has become widespread within many areas of environments, such as business, healthcare sector, and manufacturing areas. RFID provides an ideal technology for tracking assets and identifying them by using a simple low cost antenna attached to the target. It is used for identification of everything from shop tagging to vehicle tracking and improves distribution and visibility in supply chains and allows access control in security situations.
Similar to how a radio must be tuned to different frequencies to hear different channels, RFID tags and readers have to be tuned to the same frequency in order to communicate. RFID uses several radio frequencies and many types of tags exist with different communication methods and power supply sources. RFID tags generally feature an electronic chip with an antenna in order to pass information onto the interrogator (also known as a base station or more generally, reader). The assembly is called an inlay and is then packaged to be able to withstand the conditions in which it will operate. This finished product is known as a tag, label or transponder.
RFID is considered as a nonspecific short range device. It can use frequency bands without a license. Its range differs from 1–12 meters with speed of 640 kbps. RFID has to be compliant with local regulations (ETSI, FCC etc.) most countries have assigned 125 to 134 kHz of the spectrum for low-frequency RFID systems; 13.56 MHz is generally used around the world for high-frequency RFID systems. UHF RFID systems use 433, and 860-960 MHz and 2.45 / 5.8 GHz are super high frequencies.
Near Field Communication (NFC) facilitates short-range communication wireless technology among compatible devices using electromagnetic waves. The technology enables contactless data exchange through capable devices secured via a point-to-point contact over short distances. NFC uses a low data rate of 13.56 MHz frequency wireless communications. The RFID technology-based NFC offers the identification protocols a medium that confirms secure data transfer. It enables users to perform a contactless transaction, access digital content, and connect electronic devices by touching them or bringing them into close proximity. NFC based tags are embedded into credit cards, smart phones and other wearable devices and used in various applications like data exchange between two smartphones, contactless payment, transport cards, parking access management, mobile based ticketing, medical applications - patient tracking to biomedical tracking, asset tagging applications and many more.
The technology involves using inductive coupling to transport energy between two devices across a shared magnetic field. When a tag is placed close to the reader, the reader's antenna coil field pairs the tag's antenna coil. A voltage is then produced in the tag, which is subsequently rectified and utilized to power the tag's internal circuitry. The reader regulates the field to communicate its data with that tag. The tags circuitry varies the coil load to return data to the reader from the tag even as the reader's unmodulated carrier remains the same. The reader detects this due to mutual coupling. This functionality is termed load modulation.
Devices fitted with NFC chips are two types: initiator (passive) device and target (active) device. An NFC tag can be both active and passive. However, an NFC reader is always an active device. These devices function either in active-passive or active-active (peer-peer) modes. Both NFC devices have independent power in active-active mode, whereas, in active-passive mode, the passive device draws its power from the active device's electromagnetic waves. The basic mode of communication is half-duplex in NFC, wherein one NFC device transmits while the other device receives.
An important advantage of NFC is that the technology adapts to the existing RFID infrastructure, contactless smart cards, and RFID tags. An NFC-adept device combines both components: an active reader and a passive transponder. It reads data and writes it to or from a tag that receives the data, and transmits it directly to yet another NFC device.
Bluetooth is a standard for wireless communications based on a radio system designed for short-range connectivity for portable personal devices. It defines a whole communication stack that allows devices to find each other and advertise the services they offer. Bluetooth is extensively used in WPAN (wireless personal area network), aka short wireless distance network, technology. IEEE 802.15.1 standard specifies the operation and architecture of Bluetooth devices, but the operation is concerned only for physical layer and medium access control (MAC) layer. The protocol layers and applications are standardized by Bluetooth SIG. The channels are accessed using an FHSS technique, with a signal rate of 1 Mb/s, using Gaussian shaped frequency shift keying (GFSK) modulation.
Every Bluetooth using device bears a small microchip that can send both data and voice signals. One device functions as the master in any typical setup, and one or multiple devices function as slaves. This master device utilizes link manager software to discern other Bluetooth devices and create links to receive and send data. Bluetooth systems include protocol stacks, transceivers, and basebands and can create a compact network with a few devices. The systems create a big distributed network consisting of numerous independent Pico networks and a cluster of interconnected piconets termed scatternet. A simple Bluetooth system includes antennas, software, link control, and link management.
Bluetooth devices use the 2.4 GHz band, which is licence free Industrial, Scientific and Medical (ISM) frequency band for its radio signals and enables communications to be established between devices up to a maximum distance of around 100 metres. Bluetooth's main strength is its ability to simultaneously handle both data and voice transmissions, allowing such innovative solutions as a mobile hands-free headset for voice calls, print to fax capability, and automatically synchronizing PDA, laptop, and cell phone address book applications.
The two most popular implementation specifications are Bluetooth Basic Rate or Enhanced Data Rate (BR/EDR), validated as version 2.0/2.1, and Low Energy (LE) Bluetooth, validated as version 4.0/4.1/4.2/5.0. Bluetooth BR/EDR establishes a comparatively short-range, continuous wireless connection. 2-3Mbit's EDR data rate makes it ideal for use cases like streaming audio. BLE permits long-range radio connection in short bursts, making it ideal for Internet of Things (IoT) applications. Bluetooth beacons are been utilised for indoor localization, activity sensing and proximity detection based application. Usage of BLE is getting very popular as different industries are adopting for application such as Asset Tracking solution, manufacturing units, three-dimensional triangulation positioning system using BLE based beacons.
ZigBee is a global communications standards protocol under IEEE 802.15. It builds on media access control and the physical layer defined in IEEE standard 802.15.4 for low-rate WPANs. This wireless networking standard aims to monitor and control applications where relatively low data throughput levels with 10-100 meters range are required, with the possibility of remote, battery-powered sensors. Low power consumption is vital. Sensors, lighting controls, security, and multiple applications under this technology are suitable for functioning in isolated locations and harsh radio environments. ZDOs (ZigBee Device Objects) keep track of device roles, manage network join requests, and device security and discovery.
The system is specified to operate in one of the three licenses free bands at 2.4 GHz, 915 MHz and 868 MHz at 2.4 GHz the maximum data rate is 250 kbps. For 915 MHz the standard supports a maximum data rate of 40 kbps, while at 868 MHz can support data transfer at up to 20 kbps. There are three different network topologies that are supported by ZigBee, namely the star, mesh and cluster tree or hybrid networks. There are numerous advantages to the ZigBee protocol, including its reliability, scalability and ability to self-heal its mesh network.
ZigBee PRO is a version of ZigBee that carries greater capabilities like routing techniques, network hops, maximum number of devices, and network security. By adopting ZigBee PRO as an enhanced version, it is possible to provide the additional capabilities of some applications, while retaining a simpler, low cost stack and retaining the lower power consumption for those applications that do not require the additional capabilities.
ZigBee technology is simple, reliable, and quick. A ZigBee network generates self-organizing networks and accommodates multiple devices. It can create multi-channel communication and finds wide use in M2M and IoT industries, like smart grid and remote sensing in other fields. ZigBee PRO is a ZigBee version that carries better capabilities like routing techniques, Network security, and Network hops. Adoption of an enhanced ZigBee PRO version may offer additional application capabilities.
Wi-Fi (Wireless Fidelity) is a generic term that refers to the IEEE 802.11 communications standard for WLANs. It uses radio waves to provide wireless high-speed Internet and network connections based on the IEEE 802.11 standards. Wi-Fi is a trademark of the Wi-Fi Alliance, which restricts the use of the term ‘Wi-Fi certified’ to products that successfully complete interoperability certification testing.
Wi-Fi has faster speed, better security, and longer range compared with standard wireless technologies. This local area wireless technology permits electronic equipment to exchange data or go online using 5 GHz SHF ISM and 2.4 GHz UHF radio bands. Most electronic devices nowadays have integrated WiFi interfaces, like personal computers, video-game consoles, and smartphones etc. These connect to network resources (like the Internet) through a point enabling wireless network access. Such access points (commonly known as hotspots) have a range of approximately 20 meters indoors and a greater range outdoors. All WiFi networks are contention-centric TDD systems, where mobile stations and access points compete to use the same channel.
Radio Signals are keys that make WiFi networking possible. WiFi receivers (like cell phones and laptops) pick these radio signals transmitted from WiFi antennas. Receivers are equipped with WiFi cards. The WiFi card reads these signals and creates an internet connection between the network and the user.
Access points, like routers and antennas, are principal sources of transmission and reception of radio waves. Stronger antennas have longer radio transmission and have a radius of about 300-500 feet. These finds use in outdoor areas. The weaker but effective router is better suited for indoor use with its 100-150 feet radio transmission. A WiFi hotspot may be created via the installation of an internet connection access point. The access point works as a base station. The WiFi-enabled device connects wirelessly to the network when it encounters a hotspot.
Security is a major concern in WiFi, even with the availability of better encryption systems. Encryption is voluntary in WiFi, and different methods are defined. WEP lost its relevance when the WiFi Protected Access (WPA) was initiated as an 802.11i part and be implemented through a firmware upgrade. The WPA base version comes with pre-shared keys (WPA-PSK). It is intended for personal use, and thus WPA does not need an authentication server. WPA-Enterprise must use the Remote Authentication Dial-in User Service (RADIUS) Server and supports many Extensible Authentication Protocol (EAP) extensions.
WPA2 was the ratified 802.11i standard version from 2004. It is similar to WPA, but WPA2 support is compulsory for products needed to be WiFi certified. WPA3 enhances WPA/WPA2 and uses 128-bit encryption and 192-bit encryption in personal and enterprise modes. WPA3 augments Forward Secrecy.
The advancement of mobile networks is enumerated by generations. Many users communicate across a single frequency band through mobile phones. Cellular and cordless phones are two examples of devices which make use of wireless signals. Typically, cell phones have a larger range of networks to provide coverage. But, Cordless phones have a limited range. Similar to GPS devices, some phones make use of signals from satellites to communicate.
WWAN is a long-range communication using cellular network data anywhere and also with the utilization of internet. WWANs establish connection over large areas, like cities or countries, via multiple satellite systems or antenna sites looked after by an Internet Service Provider (ISP). These systems are referred to as 2G (Second Generation) systems. These networks require high cost to deployment since they cover a large geographical area. WWANs include mobile telecommunication cellular networks such as Long Term Evolution (LTE), GSM, CDMA 2000, cellular digital packet data (CDPD) and Mobitex to transfer data.
Universal Mobile Telecommunication System (UMTS) is a system of third generation (3G) of mobile services, which establish voice communications and high-speed data connectivity, including access to the Internet, mobile data applications, and multimedia content. High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA) belong to 3.5 and 3.75 generation of mobile systems respectively. HSDPA possessing bitrates of 2Mbit/s for downlink and 384kbit/s for uplink direction and HSUPA allows sending data at a bit rate of 1.45Mbit/s for the uplink direction.
4G of mobile telecommunication technology provides mobile broadband internet access to wireless modems, Smartphone’s and also to other mobile systems. 4G systems offer enhanced key services, such as HD video calling, higher bandwidth (BW), high data throughput, better QoS, and streaming online gaming services. It has a 40 MHz BW capacity and sets a 100 Mbps peak speed requirement.
5G, a nascent mobile cellular technology, enjoys a high data rate and better energy efficiency. It supports a virtual reality environment complete with ultra-HD audio/video applications and 10 Gbps data speed to augment mobile cloud services. The 5G is based on standards like CDMA (Code Division Multiple Access), WWWW (World Wide Wireless Web), and BDMA (Beam Division Multiple Access). It supports large bi-directional bandwidth having data rates greater than 1.0 Gbps with the 3 to 300 GHz proposed spectrum via ubiquitous connectivity. Cloud computing and the Internet make up the core network infrastructure, which provides reliable and quick communication services, IoT, holographic communication, Wearable wireless devices, Cloud computing, Virtual reality, advancement in secure online banking, Mobile full HD TV, telemedicine, Global roaming, Ultra HD video streaming, and Online gaming services among others. 5G boosts digital experiences via ML aided automation. Demand for snappier response times (example: self-driving cars) pushes 5G networks to advance automation with ML and, in the longer-term, AI and deep learning (DL).
6G wireless communication networks are anticipated to offer global coverage, security, enhanced spectral/energy/cost efficiency, and better intelligence level. The 6G networks, to satisfy such requirements, will rely on new validating technologies, network slicing, cloud/fog/edge computing, and cell-free architecture. The same may complement non-terrestrial networks like satellite and unmanned aerial vehicle (UAV) communication networks. This would result in a space-air-ground-sea integrated communication network, including the sub-6 GHz, millimeter wave (mmWave), terahertz (THz), and optical frequency bands.
Sigfox provides a cellular style network operator that provides a tailor-made solution for low-throughput Internet of Things and M2M applications. It connects remote devices using Ultra Narrow Band (UNB) technology and operates in the unlicensed bands (ISM). It uses a standard radio transmission method called binary phase-shift keying (BPSK).
There are a number of applications that need this form of low cost wireless communications technology. It requires an inexpensive endpoint radio and a more sophisticated base station to manage the network and is mainly targeted for low data rate applications. It requires substantially less antennas compare to traditional cellular networks such as GSM/CDMA. Sigfox has tailored a lightweight protocol to handle small messages. Less data to send means less energy consumption, hence longer battery life.
Using the Ultra Narrow Band modulation, Sigfox operate in the 200 kHz of the publicly available and unlicensed band to exchange radio messages over the air (868 to 869 MHz and 902 to 928 MHz depending on regions). Each message is 100 Hz wide and transferred at 100 or 600 bits per second a data rate, depending on the region. Hence, long distances can be achieved while being very robust against the noise. The transmission is unsynchronized between the device and the network. The device broadcasts each message 3 times on 3 different frequencies (frequency hopping). The base stations monitor the spectrum and look for UNB signals to demodulate.
The density of the cells in the Sigfox network is based on an average range of about 30-50km in rural areas and in urban areas where there are usually more obstructions and noise is greater the range may be reduced to between 3 and 10km. Distances can be much higher for outdoor nodes where SIGFOX states line of sight messages could travel over 1000km.
LoRa is a wireless technology that has been developed to enable low data rate communications to be made over long distances by sensors and actuators for M2M and Internet of Things applications. It uses unlicensed radio spectrum in the Industrial, Scientific and Medical (ISM) bands to enable low power, wide area communication between remote sensors and gateways connected to the network. It uses spread-spectrum technology with a wider band. Its frequency-modulated chirp utilizes coding gain for increased receiver sensitivity.
LoRaWAN is an open-source LPWAN (Low Power Wide Area Network) infrastructure protocol specification built on top of the LoRa technology developed by the LoRa Alliance that allows other companies to create their own IoT networks based on its technology specifications. This standards-based approach to build a LPWAN allows for quick set up of public or private IoT networks anywhere using hardware and software that is bi-directionally secure, interoperable and mobile, provides accurate localization and works the way you expect.
A LoRa network can be arranged to provide coverage similar to that of a cellular network. Indeed many LoRa operators are cellular network operators who will be able to use existing masts to mount LoRa antennas. In some instances the LoRa antennas may be combined with cellular antennas as the frequencies may be close and combining antennas will provide significant cost advantages. The key features of LoRa is it covers long range of 15-20 kilometres, it can connect to millions of nodes and its battery life long lasts for more than 10 years. Applications for LoRa wireless technology includes smart metering, inventory tracking, vending machine, data and monitoring, automotive industry, utility applications where data reporting and control may be needed.