Physical Layer Of Osi Model :: Networks Telecommunications

AbstractThe carnal socio-economic class is the lowest spirit level of the Open Source Interconnect Model (OSI). It is the layer that deals with all the measurable, natural entities associated with the network. At this layer it is specified how much bandwidth (Baseband or Broadband) will be used in the contagion of data on the network. This layer a wish well includes the physical topology (physical lay out) of the network such as Bus, Star, peal or Mesh. The Physical point includes these devices Network Interface Cards (NICs), Transceivers, Hubs, Multistation entrance fee Units (MAUs), Repeaters and Cables. It is at this layer that frames received from the Data Link layer ar converted to bits for transmission everyplace the network media to the receiving machines Physical Layer.The Physical Layer defines all electrical and physical specifications for devices. This includes the layout of pins, voltages, and cable specifications. The major functions and services perform ed by the Physical Layer are establishment and termination of a conjunctive to a communications medium, go badicipation in the process whereby the communication resources are effectively shared among multiple users, modulation, or conversion between the prototype of digital data in user equipment and the corresponding signals transmitted over a communications channel. These are signals operating over the physical cabling slovenly person and fiber optic. (OSI Model, 2005)The Physical Layer is special compared to the other layers of the model, because it is the that one where data is physically moved across the network interface. tout ensemble of the other layers perform useful functions to create messages to be sent, but they moldiness all be transmitted down the protocol stack to the Physical Layer, where they are actually sent out over the network.(Kozierok, 2004)Physical Layer also specifies how much of the media will be used during the data transmission referred to as Ba seband or Broadband signaling. 1. Baseband Signaling Technology in which a network uses all available signal frequencies or the entire bandwidth i.e., just about LAN technologies like Ethernet. 2. Broadband Signaling Technology in which a network uses only one frequency or a part of the entire bandwidth i.e., multiple signals can be transmitted over a media simultaneously like TV signals, where you have various channels like CNBC, MTV, BBC, separately on a different frequency and hence each occupies a part of the bandwidth. (Chandrasekaran, 2002)The Physical Layer also deals with the way a network is laid out which is referred to as the topology of a network.