Exercise 1 Nt1310

o Cell phones: Cell phones are both voice, and data. The first generation cell phone transmitted information in an analog format very similar to the way a fixed-line telephone transmits voice information from the subscriber to the central office. When the second generation cell phone entered the market transmission shifted from analog to digital. Not only do 2G phones have the ability to transmit and receive voice but they also have the ability to transmit and receive data.

o Landline phones: Landline phones use both voice, and data networks. Originally it was just voice, then "the data network" began with dial-up modems, and fax machines.

o SMS/ Text Messaging: Text Messaging is a data network. Cell phones pave the pathway for SMS messages. When a friend sends you an SMS message, the message flows through the SMSC, then to the tower, and the tower sends the message to your phone as a little packet of data on the control channel. Cell phone calls are different, they use radio frequencies instead.

o Fax Machines: Fax machines are in a data network. Fax machines transmit mainly through landline phones. Recently, they also send through Voice Over Internet Protocol (VOIP.)

o Pagers: Pagers are data signals that receive similar to cell phones, but with no voice radio frequencies.

o VOIP (Voice Over IP) phones: VOIP is data. It is sort of like an analog to digital translator. The data goes from voice over an Internet protocol .

o Skype: Facetime Skype is a proprietary Voice Over IP and software application, therefore, it is an application used on a data network.