US 5,394,433 AGranted

Frequency hopping pattern assignment and control in multiple autonomous collocated radio networks

AssigneeInternational Business Machines Corporation

InventorsDavid F. Bantz, Frederick J. Bauchot, Chia-Chi Huang, Fabien P. Lanne, Kadathur S. Natarajan, Michelle M. Wetterwald

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Abstract

A control system for automated management of frequency-hopping in a radio network. The system includes a Wireless Network Manager (WNM) or Controller and a Wireless Control Agent (WCA), which control the distribution and maintenance of hopping patterns in the radio network. In a single cell network, the WNM and the WCA are included in a single base station. In a multiple cell network, the WNM is in a specific station on a LAN, and a WCA is located in each base station on the LAN. In each instance, the WNM is a centralized managing station and the WCA acts as a cell controller.

Claims22

Dependent claims

A method of dynamically managing frequency hopping in a wireless communication network comprising a controller, a plurality of base stations, a local area network interconnecting said base stations with said controller, and a plurality of mobile stations, each said mobile station and base station including a transceiver for wireless bidirectional communication therebetween when in sufficient proximity to each other, said method comprising the steps of:

(a) requesting by a given base station a frequency hopping pattern assignment from said controller;
(b) monitoring by said given base station the frequency hopping pattern of the other ones of said plurality of base stations;
(c) requesting by said given base station a new frequency hopping pattern if another one of said plurality of base stations is using the same frequency hopping pattern as said given base station;
(d) beginning frequency hopping by said given base station;
(e) monitoring by said given base station interference relative to the assigned frequency hopping pattern;
(f) determining by said given base station if frequency hopping pattern revision is necessary as the result of the monitoring of interferences;
and
(g) returning to step (b) if revision is necessary, and if revision is not necessary, continuing to hop with the same frequency hopping pattern.

5 more elements

A method of dynamically managing interference in a wireless communication network comprising a controller, a plurality of base stations, a local area network interconnecting said base stations with said controller, and a plurality of mobile stations, each said mobile station and base station including a transceiver for wireless bidirectional communication therebetween when in sufficient proximity to each other, said method comprising the steps of:

(a) requesting by a given base station a frequency hopping pattern assignment from said controller;
(b) selecting by said controller a frequency hopping pattern from a predetermined set of frequency hopping patterns;
(c) determining by said controller if the selected frequency hopping pattern has been previously assigned to another one of said plurality of base stations;
(d) returning to step (b) by said controller if the selected frequency hopping pattern has previously been assigned;
(e) communicating the selected frequency hopping pattern to said given base station;
(f) locking, by said given base station, into the frequency hopping pattern of another base station to learn its frequency hopping pattern;
(g) comparing the frequency hopping patterns;
(h) requesting a new frequency hopping pattern by said given base station if the frequency hopping patterns compare within predetermined limits;
(i) beginning frequency hopping by said given base station;
(j) monitoring by said given base station interference relative to the assigned frequency hopping pattern;
(k) determining by said given base station if frequency hopping pattern revision is necessary as the result of the monitoring of interferences;
and
(l) returning to step (h) if revision is necessary, and if revision is not necessary, continuing to hop with the same frequency hopping pattern.

10 more elements

maintaining an Inactive Channel Table (ICT) in said controller for keeping track of the inactive hopping frequencies in said network, including the time of last use of a hopping frequency, the last time a hopping frequency was replaced and the base stations involved;
maintaining an Active Channel Table (ACT) in each of said base station for keeping track of whether a given hopping frequency has been relatively free of interference and therefore is considered to be good or whether the given hopping frequency has not been relatively free of interference and therefore is considered to be bad and if it has been deleted within a predetermined time;
determining if a given hopping frequency has not been relatively free of interference at a given base station, and if so updating ACT to reflect that the given hopping frequency is considered to be bad;
requesting a new hopping frequency from said controller in response to determining that the given hopping frequency is considered to be bad;
selecting said new hopping frequency from the ICT by said controller, and updating ICT to reflect the selection;
sending the new hopping frequency to each base station that was using the hopping frequency considered to be bad, and
at each base station that was using the hopping frequency considered to be bad, using the new hopping frequency instead.

4 more elements

Apparatus for dynamically managing frequency hopping in a wireless communication network comprising a controller, a plurality of base stations, a local area network interconnecting said base stations with said controller, and a plurality of mobile stations, each said mobile station and base station including a transceiver for wireless bidirectional communication therebetween when in sufficient proximity to each other, comprising:

(a) means for requesting by a given base station a frequency hopping pattern assignment from said controller;
(b) means for monitoring by said given base station the frequency hopping pattern of the other ones of said plurality of base stations;
(c) means for requesting by said given base station a new frequency hopping pattern if another one of said plurality of base stations is using the same frequency hopping pattern as said given base station;
(d) means for beginning frequency hopping by said given base station;
(e) means for monitoring by said given base station interference relative to the assigned frequency hopping pattern;
(f) means for determining by said given base station if frequency hopping pattern revision is necessary as the result of the monitoring of interferences;
and
(g) means for returning to (b) if revision is necessary, and if revision is not necessary, including means for continuing to hop with the same frequency hopping pattern.

5 more elements

Apparatus for dynamically managing a wireless communication network comprising a controller, a plurality of base stations, a local area network interconnecting said base stations with said controller, and a plurality of mobile stations, each said mobile station and base station including a transceiver for wireless bidirectional communication therebetween when in sufficient proximity to each other comprising:

an Inactive Channel Table (ICT) in said controller for keeping track of the inactive hopping frequencies in said network, including the time of last use of a hopping frequency, the last time a hopping frequency was replaced and the base stations involved;
an Active Channel Table (ACT) in each of said base station for keeping track of whether a given hopping frequency has been relatively free of interference and therefore is considered to be good or whether the given hopping frequency has not been relatively free of interference and therefore is considered to be bad and if it has been deleted within a predetermined time;
means for determining if a given hopping frequency has not been relatively free of interference at a given base station, including means for updating ACT to reflect that the given hopping frequency is considered to be bad;
means for requesting a new hopping frequency from said controller in response to determining that the given hopping frequency is considered to be bad;
means for selecting said new hopping frequency from the ICT by said controller, including means for updating ICT to reflect the selection;
means for sending the new hopping frequency from said controller to each base station that was using the hopping frequency considered to be bad, and
means at each base station that was using the hopping frequency considered to be bad for using the new hopping frequency instead.

4 more elements

Dependencies are inferred from the claim text.