Rotary dialing relies on a completely different concept. When using rotary dial, an electrical signal is applied an interrupted a number of times equal to the number the user wishes to dial. For instance, to dial a number 8 a telephone would have to interrupt the electrical signal 8 times. A pause signifies the completion of the first dialed numbered and the system prepares to receive the next number.
Voice and Data Communication Systems
Voice and data communication systems are the backbones of modern business organizations. Without these systems, business would quickly crumble due to competitors’ ability to leverage such systems to communicate changes in the market and other required business information very quickly. If my business had more than one employee and more than one location, then getting information from one point to the other without a voice or data network could potentially take long enough that my company would lose out on profits to my competitors. In short, voice and data communication systems enable businesses to survive in what has now become a world that moves at the speed of light. In this article, I will describe the voice and data communication systems I use to perform my job as an online reseller.
The Telephone System
I pay a monthly service fee to AT&T so that my home telephone is allowed to access the PSTN. The PSTN is a circuit switching network, which means a dedicated circuit is opened for a communication until that communication is closed by either of the involved parties. When I lift the handset, the hook switch inside my telephone closes and connects my telephone to the central switch. Dialing the number I wish to call informs the central switch, which then attempts to connect my call to the number I dialed. If someone answers my telephone call, then the central switch opens a dedicated circuit between our telephones. Speaking into the microphone causes the built-in speaker to modulate my voice into an electrical signal that is then placed on the dedicated circuit and sent to the other party. Once the signal reaches the other party’s telephone, the speaker receives the electrical signal on its coil and causes the telephone to reproduce the sound of my voice.
The Data Network
The telephone network in use at my house is just as beneficial for my business as my data communication network is. I am currently subscribed to Time Warner Cable’s coaxial packet switching network. In a packet switching network, a modulator/demodulator (modem) creates data packets from the information I intend to send over a computer network and sends those packets onward to their destination. The real difference between a packet switching network and a circuit switching network is in how switches on the network handle my data packets. A packet switching network could potentially send my data packets along many routes depending on network congestion.
That is just how data leaves my house and enters it. Once data arrives at my modem, it is then directed to my wireless router. My router is then responsible for determining the internal destination IP address of a data packet and transmitting that packet to its proper destination. My home network consists of two desktop computers linked with a KVM switch and wired to the router and another Desktop computer that access the network via built-in IEEE 802.11g wireless NICs. Most of the data I store for business use is saved to a Seagate 1TB external drive installed on one of the desktop computers but shared with every user on the network.
To perform my job, I receive phone calls and emails from customers interested in receiving my products. If the products are in stock, then I fax in my orders and send confirmations to the customer’s emails. If I did not have my data network at my disposal, I would not receive the email that presents a potential for providing services rendered. Moreover, my data network enables me to access information I have stored and use that information to send to the warehouse. Without the information I have, I would not be able to respond in a timely manner to requests for items in stock. My marketplace is highly competitive, and many times customers come looking for products that other web-sites are out of; therefore, being able to respond quickly and access the data has enabled my business to flourish.
Conclusion
My place of business is my home, but even there I need to make use of voice and data communications networks in order to succeed. The telephone network is just as critical to the success of my business, as the data network. Without either, I simply could not operate as an online reseller. Although my line of work is not a traditional one and has instead been born out of the information revolution brought about by the rise of the Internet, the competition is no less real than in the brick and mortar business world. My data network is an absolutely integral part of my business, and I simply have no idea how I would feed my family without it. Part B
Explain the difference between rotary and dual tone multi-frequency (DTMF):
DTMF relies on sounds created by pure sine waves, which are sound waves that have a consistent frequency from beginning to end. Two of these tones are combined into a sinusoidal wave that allows a network switch to recognize the key being pressed by separating the sinusoidal wave into its component parts.