Signals

SIGNALS – WEEK TWO

Data, voice and video signals are three very common types of signals that can move about a network. Data is electronic information that can be stored, which could also be digitally encoded voice & video. Voice is live voice that is being sent across a network from one person to another. Finally, Video is live moving images moving across the network from one person to another.

Since data does not have to be delivered in real time or “live”, the signals over a data network don’t have to be consistent and highly reliable signals. Data is typically delivered through packet switching or cell switching; which, will ensure that the data gets to where it’s going correctly, but not in real-time.

Video signals are much more demanding than both voice and data signals because they need to be able to deliver a live stream of video, as well as a live stream of voice that must be delivered in a timely fashion as to keep the integrity of the video.

Voice on the other hand, is based on circuit switching. In this case, two one open circuit (telephone 1) essentially closes and requests a closed connection with another open circuit (telephone 2).

More recent advances have introduced PBX’s and VoIP. A PBX is a telephone system that allows switching of circuits within a company, rather than having one specific line for each telephone. VoIP or Voiceover IP is a telephone system where voice is sent over the internet using packet or data switching. VoIP consists of a telephone, for example, that dials out through a PBX server which converts the voice into IP packets to be sent over a common IP Telephony gateway.

Reference: Regan, P. (2004). Wide area networks. New Jersey: Pearson Education, Inc.