Random Access-Based Protocols Traditional random access MAC-layer protocols, also known as contention-based protocols, require no coordination among the nodes accessing the channel. Colliding nodes back off for a random duration of time before again attempting to access the channel. The enhancement of these protocols with collision avoidance and request-to-send (RTS) and clear-to- send (CTS) mechanisms improves their performance and makes them more robust to the hidden terminal problem The energy efficiency of contention-based MAC-layer protocols, however, remains low due to collisions, idle listening, overhearing, and excessive control overhead. The power aware multicast protocol The power aware multi access protocol with ...
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Definition “A wireless sensor network (WSN) is a wireless network consisting of spatially distributed autonomous devices using sensors to cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration, pressure, motion or pollutants, at different locations.” – Wikipedia A very low cost low power computer- on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. It performs tasks, processes data and controls the functionality of other components in the sensor node. Monitors one or more sensors. A Radio Link to the outside world. Are the building blocks of Wireless Sensor Networks (WSN). CPU The Microcontroller ...
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Taxonomy of Protocols The design of the simplest protocol with no flow or error control https://play.google.com/store/apps/details?id=com.pratikkataria.positivityhub Simplest Protocol The sender sends a sequence of frames without even thinking about the receiver. To send three frames, three events occur at the sender site and three events at the receiver site. Note that the data frames are shown by tilted boxes; the height of the box defines the transmission time difference between the first bit and the last bit in the frame. Design of Stop-and-Wait Protocol Stop-and-Wait Protocol The sender sends one frame and waits for feedback from the receiver. When the ...
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Switching Techniques In large networks there might be multiple paths linking sender and receiver. Information may be switched as it travels through various communication channels. There are three typical switching techniques available for digital traffic. Circuit Switching Message Switching Packet Switching Circuit Switching Circuit switching is a technique that directly connects the sender and the receiver in an unbroken path. Telephone switching equipment establishes a path that connects the caller to the receiver by physical connection. Once a connection is established, a dedicated path exists between both ends until the connection is terminated. Routing decisions must be made when the circuit is first established, but ...
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What is Wireless Communication ? Transmitting voice and data using electromagnetic waves in open space (atmosphere) Electromagnetic waves Travel at speed of light (c = 3×108 m/s) Has a frequency (f) and wavelength (LAMBDA) » c = f x LAMBDA Higher frequency means higher energy photons The higher the energy photon the more penetrating is the radiation Types of wireless communication Point-to-Point Communication: Cellular Multipoint Communication: Wireless Computer Network Broadcast Communication: Radio Service Electromagnetic Waves & Electromagnetic Spectrum Transverse waves without a medium! (They can travel through empty space) They travel as vibrations in electrical and magnetic fields. — Have some ...
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VLAN A VLAN allows a network administrator to create groups of logically networked devices that act as if they are on their own independent network, even if they share a common infrastructure with other VLANs. Using VLANs, you can logically segment switched networks based on functions, departments, or project teams. You can also use a VLAN to geographically structure your network to support the growing reliance of companies on home-based workers. These VLANs allow the network administrator to implement access and security policies to particular groups of users. A VLAN is a logically separate IP subnetwork. VLANs allow multiple IP ...
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