Packet radio

related topics
{system, computer, user}
{area, community, home}
{service, military, aircraft}
{group, member, jewish}

Packet radio is a form of packet switching technology used to transmit digital data via radio or wireless communications links. It uses the same concepts of data transmission via Datagram that are fundamental to communications via the Internet, as opposed to the older techniques used by dedicated or switched circuits.



Aloha and PRNET

Since radio circuits inherently possess a broadcast network topology (i.e., many or all nodes are connected to the network simultaneously), one of the first technical challenges faced in the implementation of packet radio networks was a means to control access to a shared communications channel. Professor Norman Abramson of the University of Hawaii developed a packet radio network known as ALOHAnet and performed a number of experiments around 1970 to develop methods to arbitrate access to a shared radio channel by network nodes. This system operated on UHF frequencies at 9600 baud. From this work the Aloha multiple access protocol was derived. Subsequent enhancements in channel access techniques made by Leonard Kleinrock et al in 1975 would lead Robert Metcalfe to use carrier sense multiple access (CSMA) protocols in the design of the now commonplace Ethernet local area network (LAN) technology.

Full article ▸

related documents
Atmel AVR
Simple Mail Transfer Protocol
Visual display unit
Microsoft Windows
Single-sideband modulation
Digital Enhanced Cordless Telecommunications
Process (computing)
Dvorak Simplified Keyboard
Grid computing
E-mail client
Set-top box
Graphical user interface
Universal asynchronous receiver/transmitter
Windows 95
Zilog Z80
Microsoft Word
Flip-flop (electronics)
Three-phase electric power
Private branch exchange