Gsm channel tracking
AssigneeRaytheon Applied Signal Technology, Inc.
InventorsDaniel Cunningham, Peter Guastaferro
Life of this patent
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Abstract
A system and method for determining a correspondence between an Abis signaling channel and an air channel frequency designator. A monitoring instrument may be connected to multiple E1 circuits, monitoring messages sent on Abis signaling channels. By repeatedly observing channel activation messages (135) preceding channel assignment messages (145) of interest, or channel assignment messages (145) following channel activation messages (135) of interest, the instrument may infer a correspondence between an Abis signaling channel and an air channel frequency designator.
Claims17
A monitoring instrument, comprising:
- a processor;
- and
- a memory, wherein the memory has stored thereon instructions that, when executed by the processor, cause the processor:
- to determine a correspondence between a Global System for Mobile Communications (GSM) air channel frequency designator and an Abis signaling channel, by
- detecting a first channel activation message on the Abis signaling channel;
- detecting, during a first time interval following the first channel activation message, a first set of one or more frequency designators;
- detecting a second channel activation message on the Abis signaling channel;
- detecting, during a second time interval following the second channel activation message, a second set of one or more frequency designators;
- and
- forming a list of candidate frequency designators comprising frequency designators included in the first set of one or more frequency designators and in the second set of one or more frequency designators;
- and
- to use the correspondence to follow a call through a handover.
A method for monitoring a Global System for Mobile Communications (GSM) network, the method comprising:
- determining a correspondence between a air channel frequency designator and an Abis signaling channel;
- and
- using the correspondence to follow a call through a handover,
- the determining comprising:
- detecting a first channel activation message on the Abis signaling channel;
- detecting, during a first time interval following the first channel activation message, a first set of one or more frequency designators;
- detecting a second channel activation message on the Abis signaling channel;
- detecting, during a second time interval following the second channel activation message, a second set of one or more frequency designators;
- and
- forming a list of candidate frequency designators comprising frequency designators included in the first set of one or more frequency designators and in the second set of one or more frequency designators.
A monitoring instrument, comprising:
- a processor;
- and
- a memory, wherein the memory has stored thereon instructions that, when executed by the processor, cause the processor:
- to determine a correspondence between a Global System for Mobile Communications (GSM) air channel frequency designator and an Abis signaling channel, by
- detecting a first channel assignment message containing a first air channel frequency designator;
- detecting, during a first time interval preceding the first channel assignment message, a first set of one or more Abis signaling channel activation messages for activating a first set of one or more Abis signaling channels;
- detecting a second channel assignment message containing the first air channel frequency designator;
- detecting, during a second time interval preceding the second channel assignment message, a second set of one or more Abis signaling channel activation messages for activating a second set of one or more Abis signaling channels;
- and
- forming a list of candidate Abis signaling channels comprising Abis signaling channels included in the first set of one or more Abis signaling channels and in the second set of one or more Abis signaling channels;
- and
- to use the correspondence to follow a call through a handover.
Dependencies are inferred from the claim text.