Method of detecting a jamming transmitter affecting a communication user equipment

Patent metadata

Field	Value
Publication number	US-2017366294-A1
Application number	US-201515525399-A
Country	US
Kind code	A1
Filing date	Nov 24, 2015
Priority date	Nov 28, 2014
Publication date	Dec 21, 2017
Grant date	—

Abstract

A method for detecting a jamming transmitter affecting a communication user equipment,
operating in a cellular network supporting communication in a time-division manner, including at least one active base station, on which the user equipment is camping.

In the method, the user equipment
detects that at least one downlink radio channel from the active base station is not decodable, measures signal levels received on said downlink radio channel for a plurality of time units, analyzes said signal level measurements, and in case at least one time unit is detected with a signal level exceeding a predefined threshold, detects a jamming transmitter by verifying that, in a predefined amount of successive time units, the pattern of a first time unit with signal level exceeding the predefined threshold, directly followed by a second time unit with a signal level below the predefined threshold, is not detected.

First claim

1 . Method for detecting a jamming transmitter affecting a communication user equipment,
said communication user equipment operating in a cellular network supporting uplink and downlink communication on one frequency band in a time-division manner, the cellular network comprising a plurality of base stations, including at least one active base station, on which the communication user equipment is camping, the method comprising the following steps for the communication user equipment:
detecting that at least one downlink radio channel from the active base station is not decodable,
measuring signal levels received on said downlink radio channel for a plurality of time units,
analyzing said signal level measurements,
in case at least one time unit is detected with a signal level exceeding a predefined threshold,
detecting a jamming transmitter by verifying a condition that, in a predefined amount of successive time units, a pattern of a first time unit with signal level exceeding the predefined threshold directly followed by a second time unit with a signal level below the predefined threshold is not detected.

2 . Method according to claim 1 ,
the cellular network providing a frame structure including a special subframe comprising a downlink pilot time slot and a guard period, wherein the first time unit and the second time units are time units being part of the special subframe, and wherein the first time unit is part of the downlink pilot time slot and the second time unit is part of the guard period.

3 . Method according to claim 1 ,
wherein the predefined threshold of signal level corresponds to a decoding limit.

4 . Method according to claim 1 ,
wherein the plurality of time units corresponds to a frame.

5 . Method according to claim 1 ,
wherein said signal level corresponds to received power spectral density over time.

6 . Method according to claim 1 ,
wherein said communication user equipment comprises a communication unit and a control unit, and wherein upon detection of the jamming transmitter by the communication unit, the communication unit sending a jamming indication to the control unit, and the control unit alerting a user.

7 . Method according to claim 6 ,
the communication user equipment further comprising a jamming probability counter, the method further comprising the steps:
upon detection of a jamming transmitter, increasing the jamming probability counter,
verifying if the jamming probability counter exceeds a jamming probability threshold value,
in case the jamming probability threshold value is exceeded, sending said jamming indication,
otherwise repeating said steps of measuring and analyzing.

8 . Method according to claim 7 ,
in case repeating said steps of measuring and analyzing shows no detection of a jamming transmitter, decreasing said jamming probability counter.

9 . Method according to claim 1 ,
wherein in case the step of verifying indicates that the first time unit has a signal level below the predefined threshold and the second time unit has a signal level below the predefined threshold, detecting an out of service situation.

10 . Communication user equipment configured to operate in a cellular network supporting uplink and downlink communication on one frequency band in a time-division manner, the cellular network comprising a plurality of base stations, including at least one active base station, on which the communication user equipment is camping,
the communication user equipment is adapted to detect a jamming transmitter, the communication user equipment further comprising a channel detection unit, a measuring unit and an analyzing unit, wherein
the channel detection unit being configured to detect that at least one downlink radio channel from the active base station is not decodable,
the measuring unit being configured to measure signal levels received on said downlink radio channel for a plurality of time units,
the analyzing unit being configured to:
in response to the channel detection unit indicating that the downlink radio channel is not decodable
analyze said signal level measurements measured by the measuring unit,
the analyzing unit is further configured in case at least one time unit is detected with a signal level exceeding a predefined threshold, to detect a jamming transmitter by verifying a condition that, in a predefined amount of successive time units, a pattern of a first time unit with signal level exceeding the predefined threshold, directly followed by a second time unit with a signal level below the predefined threshold, is not detected.

11 . Communication user equipment according to claim 10 ,
wherein the cellular network in which the communication user equipment is operating, is configured to provide a frame structure including a special subframe comprising a downlink pilot time slot and a guard period, wherein the first time unit and the second time units are time units being part of the special subframe, and wherein the first time unit is part of the downlink pilot time slot and the second time unit is part of the guard period.

12 . Communication user equipment according to claim 10 ,
further comprising a communication unit and a control unit, the communication unit comprising the channel detection unit, the measuring unit and the analyzing unit, wherein upon detection of the jamming transmitter by the communication unit, the communication unit is configured to send a jamming indication to the control unit, and the control unit comprising a user interface, and the control unit is configured to alert a user by means of the user interface.

13 . Communication user equipment according to claim 12 ,
further comprising a jamming probability counter, the communication user equipment is configured, upon detection of a jamming transmitter to increase the jamming probability counter, to verify if jamming probability counter exceeds a jamming probability threshold value, in case jamming probability threshold value is exceeded, to send said jamming indication, otherwise to repeat said measuring and analyzing.

14 . Communication user equipment according to claim 13 ,
further configured, in case repeating said measuring and analyzing shows not detection of a jamming transmitter, to decrease said jamming probability counter.

15 . Communication user equipment according to claim 10 ,
wherein the analyzing unit is further configured, in case said verifying indicates that the first time unit has a signal level below the predefined threshold and the second time unit has a signal level below the predefined threshold, to detect an out of service situation.

Assignees

• Gemalto M2M Gmbh

Inventors

• Breuer Volker
• Wehmeier Lars

Classifications

• H04K2203/16

  for telephony · CPC title

• H04K3/88

  related to allowing or preventing alarm transmission · CPC title

• H04K3/222 Primary

  wherein jamming detection includes detecting the absence or impossibility of intelligible communication on at least one channel · CPC title

• H04W24/02

  Arrangements for optimising operational condition · CPC title

• H04W88/02

  Terminal devices · CPC title