Browse Prior Art Database

Standard PC-NET Hardware, Software, and Function on Non-traditional Medium utilizing Frequency Hopping

IP.com Disclosure Number: IPCOM000109218D
Original Publication Date: 1992-Aug-01
Included in the Prior Art Database: 2005-Mar-23
Document File: 3 page(s) / 158K

Publishing Venue

IBM

Related People

Cato, RT: AUTHOR

Abstract

The Wireless-LAN area of technology is presently booming with many offerings available and more on the way. Wireless local area networks (WL-LANs) include RF-LANs, power line communication LANs, and Infrared-LANs. By far and large, the WL-LANs only use a form of carrier sense multiple access (CSMA) communication protocol (listen before talk), because of difficulty in detecting collisions. There is usually some relatively simple form of collision avoidance used as well so that the protocol is sometimes known as CSMA/CA.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

Standard PC-NET Hardware, Software, and Function on Non-traditional Medium utilizing Frequency Hopping

       The Wireless-LAN area of technology is presently booming
with many offerings available and more on the way.  Wireless local
area networks (WL-LANs) include RF-LANs, power line communication
LANs, and Infrared-LANs.  By far and large, the WL-LANs only use a
form of carrier sense multiple access (CSMA) communication protocol
(listen before talk), because of difficulty in detecting collisions.
There is usually some relatively simple form of collision avoidance
used as well so that the protocol is sometimes known as CSMA/CA.

      The IBM PC-NET local area network uses CSMA/CD (carrier sense
multiple access with collision detection) communication protocol.
There is extensive software available that supports PC-NET and its
place in the OSI stack.  There is also a PC adapter that is involved
in the PC-NET protocol, and which also interfaces to the "physical
layer" hardware that connects to the actual wires or coax.  The
"physical layer" hardware is on a daughter card on the adapter card.
Different daughter cards enable a single PC-NET card to support
either base-band or broad-band PC-NET.  This article describes how
new daughter cards could be designed that would allow standard PC-NET
adapter cards and software to fully function, including collision
detection, on radio, infrared, power line, or other appropriate
non-traditional (not wire or coax) mediums.

      WL-LANs were developed to provide a simple, inexpensive way to
connect digital devices together.  Eliminating the wires produces a
significant cost and convenience advantage.  Essentially, all WL-LANs
were developed using a form of CSMA communication protocol because it
was understood, mostly standardized, relatively simple, and provided
the much desired peer-to-peer communications.

      The PC-NET protocol is CSMA/CD which is CSMA with collision
detection.  A common problem with radio and other non-traditional
mediums is that a station can only hear itself transmitting while it
is transmitting.  Being able to hear other stations' transmissions is
critical to collision detection.  Thus, all radio systems known to
the author do not detect collisions.  This article describes how a
system can be designed, utilizing frequency hopping, that would allow
standard PC-NET adapter cards and software to provide the complete
PC-NET protocol on a non-traditional medium.  Collision detection
would be done.

      The change in the FCC rules on frequency hopping spread
spectrum allow wider hopping...