Wide Area Network
Typical WAN data transfer rate
1.5 Mbps to 6 Mbps
Public Switched Telephone Network
Internet Service Provider
How are analog signals measured?
In cycles per second, or Hertz.
Hare are digital signals measured?
In bits per second (bps)
bits per second
The analog portion of voice circuit between the Central Office (CO) and the subscriber.
Digital Signal Level Zero
Digital Signal Level Zero (DSO)
The basic level of digital communication upon which all other digital signaling levels are built.
The process of combining several sets of signals onto a high-bandwidth transmission.
A path for communication between two devices.
A transmission method in which the media bandwidth is allocated to multiple channels and each channel carries a separate signal.
LAN transmission methods using digital signals at speeds of 2 to 100 Mbps.
Megabits per second
Time Division Multiplexing
Frequency Division Multiplexing
Two multiplexing technologies in use today:
Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM)
Digital Signal Hierarchy
Digital Signal Hierarchy (DSH)
A hierarchy established in North America to classify the speed capacity of multiplexing lines.
What are the 5 Digital Signal Levels of the DSH?
DS0, DS1, DS2, DS3, & DS4
A technology that uses dedicated physical path to send and receive information.
A technology that places addressing information into data packets, instead of relying upon a dedicated physical path.
Name 4 circuite-switching WAN technologies
Plain Old Telephone Service (POTS), T1/E1, T3/E3, & ISDN.
A path between hosts that appears to be a discrete dedicated connection when in fact it is not. Describes connections between hosts in a packet-switching network.
Name 4 packet-switching WAN technologies
Digital Subscriber Line (DSL), Cable modem, SONET, & ATM.
modem (technical name for it)
What is a modem?
An analog device that enables computers to communicate over telephone lines by translating digital data into audio/analog signals (on the sending computer) and then back into digital form (on the receiving computer).