International Business Machines Corporation

Francois LeMaut

Frederic J Bauchot

David Frederick Bantz

Alain R Blanc

Luc Louis Revardel

Firmin Bigo

Eliane D Bello

Frederic Bernard Lefevre

Roland Amiel

Ernesto Antunes

Marcelo Ferraz

Bernardo Da Silva Araujo Tavares

Congestion at an output from a node in a packet data communications network is controlled by maintaining a traffic profile based on the discardability/priority characteristics of recently received packets and by selecting at least an initial discard strategy which should be effective in ending congestion based on that profile. The profile is established by maintaining counts of the number of packets actually stored in an output buffer and of the number of packets which would have been stored if different discard strategies had been in force. The relationship of certain of the count values to a threshold determines which discard strategy is initially selected. Different, successively less intrusive discard strategies can be implemented until the congestion ends.

System and method for controlling communications network traffic through phased discard strategy selection

A system and method for controlling the time occupation of signalling frequencies is disclosed, in a frequency hopping system including a plurality of remote stations communicating under control of transceivers with a transceiver of a base station, such communication being performed over a shared medium through a sequence of frequency hopping periods in a plurality of operating frequencies. The method consists in selecting a set of signalling frequencies among the operating frequencies, and interleaving signalling messages transmitted on each signalling frequency within each frequency hopping period to allow a remote station to enter the network for the first time or by re-acquiring synchronization, by scanning each signalling frequency for receiving a signalling message. The method preferably employs structure and techniques for averaging over the sequence of frequency hopping periods the time occupation for data and control messages transmissions on the plurality of signalling frequencies according to the time occupation for signalling messages transmissions.

Method and system for controlling the time occupation of signalling

A wireless Local Area Network (LAN), in which each wireless adapter includes a controller and a transceiver which are located a finite distance from each other. Each controller and transceiver has their own hop clock and hop table. A data interface which includes a command set is defined between the controller and the transceiver. The command set includes commands and procedures for synchronizing the hop clocks and hop tables between the controller and the transceiver.

Command set and procedure for synchronization of frequency hopping

The device for providing protection against echoes includes a level memory (33) for storing a value Gs and a comparator (34) for comparing the level Gx provided by an AGC device (31) upon receipt of a message with a value Gs stored in the level memory (33) and for supplying a resetting signal to the equalizer (35) for resetting the coefficients thereof to zero together with a signal for storing the level Gx as a new value Gs in the level memory (33) where Gx exceeds Gs by a predetermined value, or for supplying a signal for inhibiting the decoding of the data signals where Gx falls short of Gs by a predetermined value, thereby indicating that the received message is an echo.

Method and device for protecting modems against echoes

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Nice, France

Francois LeMaut