In fact, long-distance communications through a lot done in a serial cable, such as phone lines, due to parallel transmission cables required eight-fold in the transmission of the serial cable needs.
Communication Line Configuration
Configuring the communication path is a way to connect devices that will make communication devices, can be divided into: a configuration point-to-point (point-to-point) and configuration of multi-point (multipoint).
Point-to-point (point-to-point) specially connecting two devices to communicate. This configuration is found in many parallel transmissions, such as communication between two computers in parallel to do the copying of data files, although the serial transmission is also possible if the distance between two remote devices. IMAGE: Connection Point-to-Point
IMAGE: Connection Point-to-Point
Multi-point (multipoint) suggests a relationship that allows a path used by many tools that communicate. An example is bertopologi network configuration on the bus, where a single data channel (backbone) to connect to multiple computers.
Transmission Mode
Transmission mode is a way of sending data from one device to another device, ie making synchronous (synchronous transmission) and no-sync (asynchronous transmission).
Synchronous transmission is the transmission of data to which the two parties, sender and receiver, located on the synchronous time, usually starting with a SYN signal to perform synchronization between two devices communicate, then follow the signal STX (start-of-text) that states the beginning of data transmission , then a number (block) of data sent, and closed with the ETX (end-of-text), last no signal BCC (block-check character) that is used to check for errors in receiving data.
Non-synchronous transmission is the transmission of data to which the two parties, sender and recipient need not be in time sync. Transmission mode is applied to the speed of data communication devices where the sender and receiver devices is much different. As an example of data transmission from the keyboard to be non-synchronous memory for keyboard speed is determined by the speed of the user in pressing the button (human factor), memory speed is determined by the transfer-rate from memory, but nevertheless quickly man in typing is still slower than the processor speed in transferring data. If done in sync then the memory / processor much loss of time wasted, waiting for a keypress. Non-synchronous transmission is usually performed character-by-character, where every character in the beginning by the start-of-bits (SOB) and closed with a parity-bit (for error checking) and end-of-bits (EOB).
Transmission Direction
Transmission direction of the two devices to communicate can be differentiated into three types, namely: Simplex, Half-duplex, and Full-duplex.
Simplex declared the communication between two devices can only be done in one direction only, from the source / sender to the destination / recipient. As an example of communication between the TV transmitter with TV sets, communication between the amplifier with the speaker, the communication between a computer device with a barcode.
Half-duplex communications between two devices states that can be done in two directions but not simultaneously (not simultaneously), but alternately, when one device is sending the others only receive, and vice versa. As an example of communication using the Handy-Talkie or Walki-Talkie done in half-duplex.
Full-duplex communication between two devices states that can be done in both directions and can simultaneously (same time). As an example of communication through the telephone is a full-duplex communication.
Communication between two computers can only use one third of the transmission direction, depending on the communication protocol it uses.
Multiplexing
Multiplexing associated with the effectiveness of the use of communication media, which one would be more effective if the media could be used by more than one data transmission. For example, a medium which has a large capacity (eg fiber-optics to 384 Kbps) certainly are not efficient if only used by a single low-speed transmission (for example, connect two computers with a 64 Kbps). Tools you need to do is multiplexed multiplexer (MUX) and demultiplexer (demux).
FDM (Frequency Division Multiplexing) is a multiplexing technique whereby each device given a different modulation frequency so that it can simultaneously perform transmission through a single media. FDM technique is widely used in data communication with the medium of large capacity, commonly referred to as broadband (broadband) medium. Through this technique various TV broadcasts can be channeled in a single cable (cable TV), or Video, Voice, and Data can be transmitted together in a single cable.IMAGE: Frequency Division Multiplexing, each channel uses different frequencies
IMAGE: Frequency Division Multiplexing, each channel uses different frequencies
CDM is a multiplexing technique whereby each channel or devices that communicate using different data code so that it can simultaneously (as in FDM) at a time, and both could use a different time slot (as in TDM). CDM technique enables voice communication channel bandwidth can be shared by many mobile phones.IMAGE: Code Division Multiplexing, two manuscripts with different code
IMAGE: Code Division Multiplexing, two manuscripts with different code
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