Introduction When electronic devices transfer information to another electronic device, the devices need to know when data flow is beginning and ending. This is done with signals for synchronization.i This report will describe the two forms of data communications in terms of the physical interfaces and modes of operation. It will describe the features of data communications equipment in relation to synchronous and asynchronous communication including modems, network terminating units and sending and receiving equipment. Define synchronous and asynchronous Synchronization: The receiver is able to determine when a signal begins to arrive and when it has finished. It must also know the duration of the each signal. Asynchronous Transmission: The asynchronous signaling methods use only 1 signal. The receiver uses changes on that signal to figure out the rate and timing of the transmitter, and then synchronizes a clock to the proper timing with the transmission rate. A pulse from the local clock indicates when another bit is ready. Asynchronous transmission is a slower but less expensive and effective for low-speed data communication. Synchronous Transmission: The synchronous signaling methods use 2 different signals. A pulse on one signal indicates when another bit of information is ready on the other signal. This is high speed data communication. ASYNCHRONOUS v SYNCHRONOUS TRANMISSION COMPARISON Asynchronous Synchronous Suited for low speed serial transmission. Can achieve higher speeds than asynchronous. Does not include error checking feature. Error checking feature. One (or more) character is contained in an envelope of a start and stop bit. Groups characters together into blocks. Less efficient than synchrono... ... middle of paper ... ...r line, United States NEC Corporation (Tokyo, JP) 4999836 http://www.freepatentsonline.com/4999836.html UK Yahoo.com (2009) Is a NTU a modem....why is it connected to the Cisco Router? what is it function? http://uk.answers.yahoo.com/question/index?qid=20091118020312AAjeaKk Content-Wire (2001) Deutsche Telekom Deploys ATM Network Access Solution http://www.content-wire.com/deutsche-telekom-deploys-atm-network-access-solution VoxTechnologies Corp (2010) 2902 MainStreet Network Termination Unit http://www.voxtechnologies.com/2902_mainstreet_network_termination_unit.htm RAD Data Communications, Ltd. (2010) ACE-201 multiservice network termination unit http://uk.precisionnews.com/article_ACE-201-multiservice-network_5505.html ErrealMedia (2010) Network standards OSI Reference Model; History of OSI Model; OSI Layers in Action http://www.erealmedia.com/cms125/
Handshaking is done to conduct communication of data between the sender and the receiver. In an asynchronous read operation, the bus system master will set the address and control signals on the bus system. It then declares a synchronization signal. The synchronization signal from the master sets the slave to get synchronized. The reason for this is so that when it has accessed the data, it declares its own synchronization signal. The slave's synchronization signal addresses the processor that there is legal data on the bus, and then it reads the data. This mode of synchronization is known as a full handshake.
After compression, the structure data, audio and video must be multiplexed. A number of compressed TV signals are combined by a multiplexer and put unto a shared transition medium. This is done by one of the two possible kinds of multiplexers that result in either a transport or a program stream, which is suited for secure transmission paths since it can contain large amounts of information. In addition multiplexing can be done using various methods. Time division multiplexing allocates a distinct time interval for each channel in a set; with the help of synchronization and a fixed interval order the channels take turns using the common line.
Messages distributed by institutions such as the media have the potential to reach very large and anonymous audiences in a process called mass communication. In the movie Super Size Me, Morgan Spurlock documents a month of eating McDonald's, only to prove how food media affects the way Americans are living extremely unhealthy lives. According to The Mediated Communication Process (modified Westley-MacLean model) communication starts with an event, which in this case is the two teenage girls that decided to sue McDonald's for their obesity, then there are sources, a message, a communicator, another message and then the audience.
A normal radio communication system is made of two separate components, a transmitter and a receiver. The transmitter emits an electrical fluctuation at a frequency known as the carrier frequency. Frequency modulation has more than just one pair of sidebands, which produces the variations that translate into the speech or any ot...
Digital transmissions are very different from analog transmission. A digital transmission is a series of pulses that are ones or zeroes and these ones and zeroes make up combinations to create characters in characters sets. The way the signal is carried depends on whether the network is electrical or optical. In an electrical network, the ones and zeroes are either high voltage or low voltage. With an optical network, it is either the presents of light or no light.
Ethernet is a household of processor interacting machineries for local area networks. Ethernet was brought to light in 1980 and consistent in 1983 as IEEE 802.3. Ethernet has basically substituted rival online local area network machineries such as token ring, FDDI, and ARCNET. The Ethernet ethics include some cabling and beckoning alternates of the OSI physical layer in use with Ethernet. The unique 10BASE5 Ethernet recycled coaxial cable as a collective medium. Well along the coaxial cables remained exchanged with twisted pair and fiber optic contacts in combination with hubs or switches. Figures rates stood sporadically increased from the innovative 10 megabits per second to 100 gigabits per second. Structures talking across Ethernet split a brook of info into smaller parts called frames. Each frame held basis and endpoint discourses and error-checking information so that dented data can be perceived and re-transferred. As per the OSI model Ethernet delivers amenities up to and counting the info connection layer. Meanwhile its profitable announcement, Ethernet has booked a great grade. Landscapes such as the 48-bit MAC statement and Ethernet frame arrangement have prejudiced other interacting protocols.
Digital subscriber line (DSL) technology transforms an ordinary telephone line into a broadband communications link, much like adding express lanes to an existing highway. DSL increases data transmission rates by a factor of twenty or more by sending signals in previously unused high frequencies. DSL technology has added a new twist to the utility of twisted-pair telephone lines.
Communication is an interdependent process of sending, receiving, and understanding messages. The definition implies that the components of the communication process cannot be examined separately. Rather, the relationship exists between the sender and the receiver, as well as the environment of the communication event, must be viewed as a whole. According to this perspective, if any of the components and circumstances change (that is, the number of individuals involved in the interaction, seating arrangements, or the time of the day) the communication event is altered. Communication is an ongoing process; we never stop sending and receiving messages. As we will discover, communication is a dynamic process, a process that changes from one communication setting to the next. Although it is difficult to predict, the ways of interpreting communication, certain components are always present in the communication process.
Van Matre, D.L. (1999) Overview of cable modem technology and services. Cable Data Communications. [No pagination]. Retrieved September 20, 1999 from the World Wide Web://http://www.cabledatacom.com/cmic/mic1.html
Communication is now instantaneous. Electronic communication has come a long way in the past century. It started with person to person communication via the telegraph, eventually evolving with devices like the telephone. Communication became quicker and the ability to mass communicate became available to a select few. In recent years, further development of the internet has made it possible for an individual or a business to mass communicate on its own.
There are several advantages to the layered approach provided by the OSI model. With the design separated into smaller logical pieces, network design problems can be easier to solve through divide and conquer techniques. Vendors who follow the model will produce equipment that is much more likely to be compatible with equipment from other vendors. The OSI model also provides for more extensible network designs. New protocols and other network services are more easier added to a layered architect.
People in the present society have turned from the use of the old means of communication to the more advanced and technological ways of communicating. Technology has made it easier for people to communicate in a faster, efficient, and cost saving means through the introduction of the communication channels. The world has turned out to be the centre for technology with different technologies emerging daily as the people continue to develop from time to time to cope with the growing technology. The benefits of adopting the communication technology are explained in this article which shows why people do not function without technology.
The telephone provides a perfect example of the integration of the newest technologies in a large, complex, electronic system controlled by computers and micro-processors. Fiber optics, networking and wireless communications are among the many technologies incorporated into the telephone system in recent years. Computers have been added to control the system and provide many specialized custom services. One of the most important tasks of the computers is to de...