Voice vs Data
There are only a few similarities between transmitting information over voice and transmitting information over data. The permanent virtual circuit of a data line is the main similarity to a voice connection which uses full duplex on PSTN circuits. These two types of connection are used by multiple services to date. Cell phones use data networks to transmit information. Data networks transfer information using a series of packets. This allows for the “always on feature of today’s cell phones. Landline phones are an example of technology which still uses voice networks. These networks transfer data over a connected line running full duplex meaning data travels in one direction over one line and another direction over a separate line. SMS/Text messaging is another example of data transfer that cell phones use for communication these days. Fax machines are connected through landline connections which as mentioned before use voice connections. Pagers use a voice connection as well to transfer data. The information is sent through a telephone number over a voice connection and then forwarded on to the pager dedicated to that specific number. VOIP phones use data connections to transfer voice. This is the data-transfer equivalent to a voice-transfer landline telephone. Skype is an example of one of the voice over IP connections, as is Facetime. Both services transfer audio and video over an IP address in packets which is then sent over the network to the other user. Networks which transfer information over voice networks vary greatly from networks which transfer over a data connection. Data connections are typically more efficient by allowing the information to be broken down in to packets and then reassembled by the receiving device once the destination is reached. Voice networks use an older system to transfer data back and forth over two dedicated lines which is referred to as full-duplex