Wireless Network is a Network that uses Wireless for Communication for data and voice transmission. Wireless Network doesn’t use physical cables for data transmission rather it uses radio waves to transmit data. Wireless Personal Area Network, Wireless Local Area Network (WLAN), Cellular Networks, Wireless Metropolitan Area Network (WMAN), Wireless Wide Area Network (WWAN) are various Wireless Networks used across the globe for communications.
Evolution of Wireless Networks
Wireless Local Area Network (WLAN)
Wireless LAN (WLAN) provides wireless network for communication between system within a LAN. WLAN has evolved overs the year.
ALOHAnet also known as ALOHA System or ALOHA was the initial Wireless Computer Network that was developed in University of Hawaii. ALOHAnet was operational in 1971. ALOHAnet demonstrated wireless packet transmission.
Wireless LAN (WLAN) emerged in 1990s. IEEE 802.11-1997 was the first wireless standard developed for WLAN by IEEE in 1997. IEEE 802 is a standard family for Local Area Network (LAN), Personal Area Network (PAN) and Metropolitan Area Network (MAN). IEEE 802.11 the family of standards for Wireless LAN. It specifies the standard to be implemented and followed at Layer 1 and Layer 2 of OSI Layers for Wireless LAN (WLAN). Different standards used
To support IEEE, a group of companies formed Wi-Fi Alliance in 1999 for performing testing & certifying wireless products for interoperability and backward combability with respect to family of 802.11 wireless standards. It also provides technology advancement and innovation for Wireless LAN (WLAN). Wi-Fi is trademark of Wi-Fi Alliance and provides this trademark for the certified wireless products.
IEEE 802.11-1997 used 2.4 GHz (FHSS/DSSS) and operated at speed 1 to 2 Mbps which was replaced by IEEE 801.11b (11 Mbps & 2.4 GHz & DSSS) and IEEE 802.11a (54 Mbps & 5 GHz & OFDM). In 2003, IEEE 802.11g was released which operated 54 Mbps using 2.4 GHz (OFDM) which replaced IEEE 802.11b. In 2009, IEEE 802.11n was released which was dual band using both 2.4 GHz and 5 GHz (MIMO-ODFM) providing maximum speed of 600 Mbps. Later other standards like 802.11ac, 802.11ax, 802.11be and 802.11bn were released.
IEEE 802.11i is amendment of IEEE 802.11 standard for wireless security that specifies security mechanism for wireless network that was brought in 2004. Wired Equivalent Privacy (WEP) was the initial encryption algorithms for 802.11 but it was weak and vulnerable which could be exploited by attackers. WPA (Wi-Fi Protected Access) was intermediate encryption algorithm to address the security issues of WEP. 802.11i standard brought in WPA2 encryption algorithm which had stronger security algorithms and then later WPA3 was introduced which further brought in stronger security into Wi Fi.
Wireless Personal Area Network (WPAN)
Wireless Personal Area Network (WPAN) are short range wireless communications. IEEE 802.15 is the standard developed in 1999 for WPAN that provides speed between 20 Mbps to 50 Mbps.
Bluetooth is a wireless communication technology based on IEEE 802.15.1 which is used for short range data and voice communications between computing devices specifically for personal purposes like connecting headsets, keyboard, smart watches.
Zigbee is technical specification based on IEEE 802.15.4 for short range communication meant for low powered devices. Internet Of things (IoT) which is used to connect smart things to Internet uses Zigbee. Apart Zigbee is used in industry automation, smart homes, street and road lightings which is low-powered and requires low data rate.
Wireless Metropolitan Area Network (WMAN)
Wireless Metropolitan Area Network (WMAN) are high speed wireless communication network for connecting buildings or cities. IEEE 802.16 is the standard developed for WMAN. Worldwide Interoperability for Microwave Access (WiMAX) is the branded commercially used name for IEEE 802.16 standard.
Cellular Networks
Cellular Network also known as Mobile Network is a telecommunication network that provides wireless network for mobile endpoints. The Cellular Network comprises fixed transceivers known as Base Stations. These Base Stations connect the mobile endpoints. The coverage area of each Base Station is known as a Cell and hence this network is called as Cellular Network. The Base Station connects to Mobile Switching Center (MSC). Multiple Base Stations connect to MSC. MSC connect to Public Switched Telephone Network (PSTN). The PSTN gives global connection across the world.
1G is the first-generation cellular network that was introduced in 1979 which used Analog Signaling for carrying voice for the mobile end users. It is based on circuit switching and used frequency division multiple access (FDMA).
2G is second-generation circuit switching based cellular network that used Digital Signaling which came in 1991. It provided voice and data services using technologies GSM (Global System for Mobile Communication) based on Time Division Multiple Access (TDMA) developed by European Telecommunications Standards Institute (ETSI) and CDMA (Code Division Multiple Access) developed by Qualcomm. 2G supported text messages, picture messages and MMS (Multimedia Message Service). CDMA was mostly used in US while other parts of world used GSM.
2.5G an upgrade of 2G systems provided higher speed using packet switching leveraging General Packet Radio Service (GPRS) technology. General Packet Radio Service (GPRS) was developed by 3rd Generation Partnership Project (3GPP).
2.75G provided more speed on GPRS using Enhanced Data Rates for GSM Evolution (EDGE) technology developed by 3rd Generation Partnership Project (3GPP).
3G was the third-generation of cellular network that came out in 2001. 3GPP and 3GPP 2 were two groups which had member organizations that developed standards and paved way for 3G that replaced 2G. 3GPP developed Universal Mobile Telecommunications System (UMTS) that used Wideband Code-Division multiple Access (WCDMA). HSPA (High-Speed Packet Access) was developed that provided enhancements to UMTS. 3GPP 2 developed CDMA2000 that provided higher speed compared to CDMA.
4G was the fourth-generation of cellular network that unified the complete mobile network with a single standard technology Long-Term Evolution (LTE) which was considered 2.95. LTE Advanced was considerd as the true 4G standard across the globe for 4G cellular network. 4G is all-IP (all-Internet Protocol) for both voice and data. LTE uses orthogonal frequency-division multiplexing (OFDM).
5G, the fifth generation of cellular network is based on 5G NR (5G New Radio) standard developed by 3GPP. This uses orthogonal frequency-division multiplexing (OFDM) as 4G LTE.
As Internet evolved with data and voice being digitized with increased speed requirements, wireless communications also grew significantly complementing Internet growth. WLAN along with WMAN & WPAN and Cellular Network provided wireless network at home, organization and cities giving users extensive Internet access. Satellite Communication Network growth also was significant that complemented both WLAN and Cellular Network.
Reference
IEEE 802.11, The Working Group Setting the Standards for Wireless LANs