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Affichage des articles du janvier, 2022

LPWAN networks

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 LPWAN networks LPWANs are wireless, low-power, low-speed and long-range networks networks, optimized for equipments needing an autonomy of several years.  LPWANs use the unlicensed frequency bands called ISM (Industrial, Scientific, Medical). The use of ISM bands implies the sharing of resources with competitors and other competitors and with other technologies (Wifi, Zigbee, Bluetooth, RFID, etc.).  This type of network is suitable for applications that need long-range communications (dozens of km).  This type of network is suitable for applications that need long range communications (dozens of km) and that use low power objects. The transmission transmission speed for LPWAN is 300 bps to 5 kbps (with a bandwidth of 125 kHz).  We can find these networks in smart cities, precision agriculture, e-health, etc... LoRa vs Sigfox - Sigfox is designed to send 140 messages of 12 bytes at 300 bauds per day and receive 4 messages per day receive 4 messages per day whil...

Wireless Network

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  Digital wireless communication is not a new idea. Earlier,  Morse code   was used to implement wireless networks. Modern digital wireless systems have better performance, but the basic idea is the same. Wireless Networks can be divided into three main categories: System interconnection Wireless LANs Wireless WANs System Interconnection System interconnection is all about interconnecting the components of a computer using  short-range radio . Some companies got together to design a short-range wireless network called  Bluetooth  to connect various components such as monitor, keyboard, mouse and printer, to the main unit, without wires. Bluetooth also allows digital cameras, headsets, scanners and other devices to connect to a computer by merely being brought within range. In simplest form, system interconnection networks use the master-slave concept. The system unit is normally the  master , talking to the mouse, keyboard, etc. as  slaves . Wirel...

Wide Area Network (WAN)

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  It is also called WAN. WAN can be private or it can be public leased network. It is used for the network that covers large distance such as cover states of a country. It is not easy to design and maintain. Communication medium used by WAN are PSTN or Satellite links. WAN operates on low data rates. Characteristics of WAN It generally covers large distances(states, countries, continents). Communication medium used are satellite, public telephone networks which are connected by routers. Advantages of WAN Covers a large geographical area so long distance business can connect on the one network. Shares software and resources with connecting workstations. Messages can be sent very quickly to anyone else on the network. These messages can have picture, sounds or data included with them(called attachments). Expensive things(such as printers or phone lines to the internet) can be shared by all the computers on the network without having to buy a different peripheral for each computer. Ev...

Metropolitan Area Network (MAN)

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  It was developed in 1980s.It is basically a bigger version of LAN. It is also called MAN and uses the similar technology as LAN. It is designed to extend over the entire city. It can be means to connecting a number of LANs into a larger network or it can be a single cable. It is mainly hold and operated by single private company or a public company. Characteristics of MAN It generally covers towns and cities (50 km) Communication medium used for MAN are optical fibers, cables etc. Data rates adequate for distributed computing applications. Advantages of MAN Extremely efficient and provide fast communication via high-speed carriers, such as fibre optic cables. It provides a good back bone for large network and provides greater access to WANs. The dual bus used in MAN helps the transmission of data in both directions simultaneously. A MAN usually encompasses several blocks of a city or an entire city. Disadvantages of MAN More cable required for a MAN connection from one place to a...

Local Area Network (LAN)

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  LANs are used widely as it is easy to design and to troubleshoot. Personal computers and workstations are connected to each other through LANs. We can use different types of topologies through LAN, these are Star, Ring, Bus, Tree etc. LAN can be a simple network like connecting two computers, to share files and network among each other while it can also be as complex as interconnecting an entire building. LAN networks are also widely used to share resources like printers, shared hard-drive etc. Characteristics of LAN LAN's are private networks, not subject to tariffs or other regulatory controls. LAN's operate at relatively high speed when compared to the typical WAN. There are different types of Media Access Control methods in a LAN, the prominent ones are Ethernet, Token ring. It connects computers in a single building, block or campus, i.e. they work in a restricted geographical area. Applications of LAN One of the computer in a network can become a server serving all the ...

Communication networks

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  Types of Communication Networks In general, a communication network is composed of a set of connections ensuring the routing of information between entities or terminals. It includes  ideally: transmitters, receivers, a message, and transmission channels. The location of the network, the field of application and the distance between the different terminals, will influence the nature of the communication. We can distinguish three types of We can distinguish three types of networks according to the distances between the equipment: - PANs (Personal Area Networks) are very short distance networks (less than 100 m), which require the immediate proximity of the objects with the device intended to to connect them to the network. Bluetooth, Z-Wave or ZigBee are examples of PAN technologies. - LANs (Local Area Networks) are medium-range networks (100 m to a few km) km), domestic or professional like Wi-Fi. - WANs (Wide Area Networks) are extended networks, at the scale of a city or a...