Browse Prior Art Database

Packet Relay System for Wireless LAN

IP.com Disclosure Number: IPCOM000117354D
Original Publication Date: 1996-Feb-01
Included in the Prior Art Database: 2005-Mar-31
Document File: 4 page(s) / 79K

Publishing Venue

IBM

Related People

Ishikawa, H: AUTHOR [+2]

Abstract

Disclosed is a system that allows a shadowed wireless LAN user terminal to communicate with a wireless LAN access point. It consists of a wireless LAN access point, wireless LAN relay terminals, and wireless LAN user terminals. The relay terminal is one of the user terminals, but it has an additional function for relaying packets between the access point and a user terminal that becomes unable to communicate directly with the access point because of temporary shadowing.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 53% of the total text.

Packet Relay System for Wireless LAN

      Disclosed is a system that allows a shadowed wireless LAN
user terminal to communicate with a wireless LAN access point.  It
consists of a wireless LAN access point, wireless LAN relay
terminals, and wireless LAN user terminals.  The relay terminal is
one of the user terminals, but it has an additional function for
relaying packets between the access point and a user terminal that
becomes unable to communicate directly with the access point because
of temporary shadowing.

      Fig. 1 shows an example of a wireless LAN system.  The access
point is an interface between a wireless cell and a backbone network.
It also functions as an access controller in the wireless cell.  It
broadcasts beacon packets to the terminals in the wireless cell
periodically.  The beacon includes access control information.

      A moving obstacle, such as a human body, may cut off the
line-of-sight path of radio waves between the access point and a user
terminal.  This phenomenon is called shadowing.  The shadowing causes
a significant attenuation of receiving power.  The user terminal is
not able to receive beacon packets from the access points when
shadowing occurs, and is therefore unable to get the access control
information.

      The relay terminal broadcasts relaying beacon packets
periodically to transmit the access control information to the
shadowed user terminal.  The shadowed user terminal requests the
relay terminal...