[0001] A present invention relates to a method of detecting a jamming transmitter affecting
a communication user equipment, wherein said communication user equipment, having
a communication module, is adapted for communication with a component of the radio
network based on a cellular global system for mobile communications and having a number
of user equipments and a number of base stations. The invention also relates to a
system comprising the module and an application layer.
[0002] Contemporary, cellular radio networks are known since many years now meanwhile based
on different technologies. The broadcast carrier still is held by the global system
for mobile communications according to the so called GSM standard. A user equipment
in such cellular network can move freely and may be handed over to various cells of
the radio networks as e. g. described in GSM standards specification 3GPP ETSI TS51.010
or the like.
[0003] Contemporary, radio networks are based on a cellular code division multiple access
(CDMA) as e. g. realized in the universal mobile telecommunication system (UMTS).
The latter is increasingly important for security applications like camera systems
or the like. Nevertheless, still also the GSM standard is overly important in the
majority of security systems or the like.
[0004] Generally, a user equipment in radio networks can be subject of being affected by
a jamming transmitter-jamming in this context generally is performed by an instrument
preventing a user equipment from receiving signals from its base station. In use the
jammer effectively disables cellular phones mostly by broad frequency interference
with communication frequencies of the user equipment at high power level. Whereas
some jammer applications are meant to be legal for instances in places where phone
call is to be suppressed due to silence conditions. Other jammers are applied during
misuse for instances to interrupt security applications of user equipment or the like.
Jammers are available for jamming GSM and also UMTS frequencies.
[0005] CA 2 433 242 suggests a method for detecting a jammer at a mobile or terminal through a comparison
of the average power level of the common control channel and a predicted noise floor
in the event that a mobile or terminal no longer receives an intelligible signal from
the cellular network. If this comparison results in a lower value of a predefined
threshold plus a certain margin the condition for detecting a jamming situation is
met.
[0006] In
WO2005/112321 a method for jamming detection in a GSM mobile telecommunications network is described
comprising the steps of, at a user equipment registered with the mobile telecommunications
network: a) measuring a signal power level in at least one of a plurality of communication
channels between the user equipment and a base station within a band of operation
of the mobile telecommunications network; b) checking whether the signal power level
in said at least one communication channel is greater than a threshold MNPL and, if
so, attempting to decode a Base Station Identity Code BSIC broadcast by the base station
in said communication channel; c) repeating steps a) and b) for a certain number of
channels; d) signaling a jammed condition report JDR message to the base station if
said BSIC cannot be decoded for said number DCMN of channels. This method suffers
from the fact that usually a signaling of a jammed condition report JDR message to
the base station is not possible due to the jammed condition; thus the jammed condition
remains unanswered.
[0007] A further anti-jamming solution is known from
WO 2007/019814 which is restricted to the GSM standard. Therein a method for detecting a jamming
transmitter affecting a communication terminal is described wherein receipt radio-channel
signal levels are evaluated at periodic intervals on a signaling channel. In the case
that the communication terminal detects a radio-channel signal level that exceeds
a predefined threshold value in the signaling channel but is nevertheless unable to
decode a message content of a message, then this state is interpreted as an interference
state and an alarm signal is emitted.
[0008] In document
EP 1 363 421 a system is disclosed which is configured to detect a jammer in particular in a car.
For that the system comprises a receiver and a filter and a channel selector / analyser.
The steps are as such that signal strengths of one or more channels are measured,
and after comparison with certain predefined values or patterns it is decided that
a jammer is present.
[0010] However, all the above mentioned approaches suffer from the fact that a jamming situation
can only be detected rather than prevented. However, jamming preventing solutions
are highly desirable for both GSM and UMTS standards, in particular against GSM jammers.
[0011] In this regard, it should be recognized that primary aim of an anti-jamming solution
is to undoubtedly detect a jamming attack but nevertheless preventing the same shall
be possible as well. At least a rather early detection of a jamming attack can help
to prevent the same.
[0012] Usually, jamming results in a user equipment losing connection to the base station;
thus camping of a user equipment in the certain cell is no more possible. Technically
speaking, the user equipment falls back from a connected mode to an idle mode. An
idle mode of a user equipment according to the GSM standard is e. g. described in
3GPP ETSI TS 45.008.
[0013] The above jamming approaches have the aim to detect a jamming situation only in the
idle mode. It is known for instance from technical specification 3GPP ETSI TS23.022
that the idle mode still preserves certain operations as the user equipment is still
registered in the radio network, that is when the user equipment (also referred to
as a mobile station MS) is switched on but has no dedicated channel allocated. Thus,
the mobile station is not able to make or receive a call.
[0014] In particular certain idle mode tasks are still possible to provide a radio subsystem
link control as it is described in technical specification 3GPP ETSI TS45.008 chapter
6. As outlined above, a jamming detection in the idle mode is rather late and thus
limits the chances to prevent a jamming situation.
[0015] This is where the invention comes in, the object of which is to provide an improved
method of detecting a jamming transmitter affecting a communication user equipment.
In particular it is an object of the invention to provide a method of detecting a
jamming transmitter rather early, in particular prior that the user equipment falls
back into the idle mode. A further object of the invention is to provide an improved
communication module, in particular user equipment, adapted to execute the method
of detecting a jamming transmitter affecting the communication user equipment, in
particular to detect the jamming situation already whilst the communication user equipment
is in a connected mode; preferably before the connection breaks down. In particular
the method and the communication module shall be adapted to detect a jamming warning
before a jammed situation is to be accepted; in particular it shall be discriminated
between an out of service state of the user equipment and a jamming warning situation.
[0016] As regards the method, the object is achieved by the method of the invention as claimed
in claim 1. The method and developed configurations thereof as outlined above may
be implemented by digital circuits of any preferred kind, whereby the advantages associated
with the digital circuits may be obtained. In particular one or more method steps
and/or features of the method can be implemented by one or more means for functionally
executing the method step. A single processor or other unit may fulfill the functions
of several means recited in the claims - this in particular holds for user equipment
according to the concept of the invention.
[0017] The invention also leads to a system of a communication module and an application
layer, being part of a communication user equipment, as claimed in claim 13.
[0018] Said communication user equipment and a number of base stations are components of
a radio network, in particular based on a cellular global system for mobile communications
(GSM).
[0019] The invention starts from the consideration that instant approaches for detecting
a jamming situation are based on measurements at a mobile station (user equipment
UE) in the idle mode. The instant invention recognized that nevertheless it is also
possible to find sufficient indication for a jamming situation when the user equipment
is in a connected mode of a communication radiolink to a component of the radio network;
thus wherein during the connected mode the user equipment has a dedicated channel
allocated. So to say, the instant invention starts from the recognition that a jamming
detection already is possible in a status where the mobile station has a dedicated
channel allocated; thus is able to make or receive a call. Advantageously this approach
allows for detecting a jamming attack even during a call or connection, i. e. an in-call/connection
jamming detection concept is provided. Consequently, the method is characterized by
providing the user equipment in a connected mode of a communication radiolink to a
component of the radio network. More precisely, the method provides a basis to observe
the impact of the jammer, respectively jamming power, on an existing radiolink. Preferably
the user-equipment indeed can be in an active-status, i. e. is switched on. Consequently,
the method preferably further is characterized by providing the user equipment in
an active-status, respectively switched on.
[0020] According to the invention the first power indicator is set before the second power
indicator, before evaluating whether the communication radiolink is affected by a
radiolink error. Nevertheless, it can be useful also to set the first power indicator
even during evaluating whether the communication radiolink is affected by a radiolink
error as soon as it can be assumed that the first power indicator somewhat reflects
a situation wherein the user equipment is not totally blocked by a jamming transmitter.
[0021] According to the invention the early power indicator is set by measuring an early
power indicator, in particular at a first time (t1), indicative of a received radio
signal strength.
[0022] In short terms a power indicator indicative of a received radio signal strength,
in particular over the used radiofrequency of the communication user equipment (UE)
is determined in a state of the user equipment which can be assumed to be undisturbed.
In particular the communication user equipment is assumed to be undisturbed, in the
case a radiolink-timeout counter has a value above an upper threshold value, which
is below a maximum value. Preferably the power indicator at this --in particular early--
point of first time is stored or held in a similar way. Further firstly it is evaluated
whether the communication radiolink is affected by a radiolink error. A radiolink
error is assumed to enclose any kind of disturbance of the radiolink which can be
measured or determined actually.
[0023] Preferably, the first time is before a radiolink evaluation and the second time is
during or after the radiolink error identification, and wherein in case of the radiolink
error identification the early power indicator determined at the first time before
the radiolink error identification is compared to the later power indicator determined
at the second time after the radiolink error identification. A situation during the
radiolink error identification e.g. can be assumed in the case the radiolink-timeout
counter or another scoring counter has a value below an upper threshold value, in
particular which is below a lower threshold value.
[0024] In case of a radiolink error identification an early power indicator determined at
a first time before the radiolink error identification is compared to a later power
indicator determined at a second time after the radiolink error identification. Thus
according to the concept the later power indicator determined at a second time after
the radiolink error identification is determined whilst still the connected mode exists;
in other words before a radiolink-failure which involves a broken connection. A jamming
affection is indicated in case the comparison shows that the received wide band radio
signal strength is unchanged or has increased from the first time to the second time.
[0025] The concept of the invention thus has an advantage overcoming solutions wherein a
jamming detection is possible only in the idle mode or even only in the out of service
mode. Instantly, the concept provides a method for detecting a jamming situation in-call/connection,
that is to say, already when a dedicated channel is allocated for the mobile station
a jamming situation or an approach of a jamming situation can be detected. This has
the advantage that a camera or other security systems can provide a better performance.
An anti-jamming detection is rather quick and countermeasures can be provided in a
broader and earlier range.
[0026] For instance according to a known approach, a jamming detection is based on detecting
that no cell can be received (BCCH) although a high RSSI level is measured. But in
a jamming situation a mobile station will at first loose the connected mode of a communication
radiolink and will than fall back into the idle mode. Subsequently, the mobile station
will have to provide a band or channel search and only in the case this search is
not successful a jamming situation can be assumed. In this stadium the mobile station
might already be in the out of service situation. This is disadvantageous as it takes
time to identify a jamming situation. However time is a valuable parameter in security
applications like camera systems or the like.
[0027] By determining a power indicator and evaluating a radiolink error in the connected
mode, i. e. in-call/connection, the concept of the invention is able to indicate a
jamming situation already when the user equipment still is functioning in a connected
mode, although the radiolink in the connected mode is already endangered. This will
in particular be possible in a preferred development before a radiolink timeout counter
has reached a first threshold value, which is not the lowest threshold, like above
zero or the like; i. e. before a (total) radiolink failure with broken connected mode.
Thus, there is a good chance that the mobile station or user equipment will be able
to safely submit a jamming warning; early countermeasures then can be taken successfully
to prevent further continuation of the jamming attack.
[0028] These aspects of the invention and further developments thereof are further outlined
in the dependent claims. Thereby the mentioned advantages of the proposed concept
are even more improved.
[0029] Preferably a power indicator can be any suitable parameter which is directly measurable
or can be deduced from a measurable parameter. In particular the received radio signal
strength is a received wide band radio signal strength over the used radiofrequency
of the communication user equipment. In particular in the communication module the
power indicator is an indicator for a downlink power; preferably the power indicator
is or can be deduced from an unbiased downlink power indicator like a received signal
strength indicator (RSSI) or the like.
[0030] Generally it is preferred that a jamming affection is indicated to an application
layer to perform also evaluation functions. An application layer can be interfaced
to and/or integrated in a communication module. In particular in a user equipment
an application layer can be interfaced to the user equipment; e.g. by means of an
interface apart from the communication radiolink by connection of the communication
module and the application layer. In a variant the communication module can be adapted
to perform also evaluation functions in an application layer integrated in the module.
[0031] In a preferred development, of course, preferably to provide the radiolink evaluation,
it is evaluated whether the communication radiolink is affected by a radiolink-failure,
and wherein in case of a radiolink-failure identification
- the early power indicator determined at the first time before the radiolink-failure
identification is compared to a later power indicator determined at a second time
after the radiolink-failure identification, and
- a jamming affection is indicated in case the comparison shows that the received wide
band radio signal strength is unchanged or has increased from the first time to the
second time.
[0032] Thus, at least, in the development a jamming affection is indicated due to indicating
a radiolink-failure once a second counter-threshold is passed, in particular indicating
a radiolink-failure once the scoring-counter falls below the second counter-threshold,
e. g. the lowest counter-threshold like zero or the like. Although the development
takes in to account the possibility of a broken connected mode, nevertheless a jamming
indication can be given early, in particular given immediately before an idle mode.
[0033] As mentioned above a radiolink error is assumed to enclose any kind of disturbance
of the radiolink which can be measured or determined actually. A radiolink error in
particular can be identified due to one, in particular a number of radiolink-irregularities
e.g. due to a broken block and/or broken link and/or. A rather severe kind of a radiolink
irregularity is a radiolink failure, wherein a radiolink-failure is identified due
to a fully decremented radiolink-failure timeout counter. A radiolink error identification
in the method thus is possible on basis of any radiolink irregularity, in particular
a radiolink-failure or another radiolink irregularity. Thus, a radiolink error can
be specified according to a rather sensitive setting, namely any radiolink irregularity,
in particular arising from a failure to receipt a sent test message, e.g. on a SACCH.
Consequently, in case of an early power indicator exceeding a later power indicator
an early jamming evaluation can be given well before a totally broken connection due
to a radiolink-failure wherein a radiolink timeout counter already has reached a timeout-value.
[0034] Further developed configurations of the invention are further outlined in the dependent
claims. Thereby, the mentioned advantages of the proposed concept are even more improved.
[0035] In a particular preferred development determining the power indicator and evaluating
the radiolink error, in particular any kind of a radiolink-failure or irregularity,
in combination is repeated in a predetermined time sequence. Advantageously, this
or other kind of repetition in a loop practically allows a steady supervision of a
user equipment against a jamming attack.
[0036] In a preferred development the power indicator is an indicator for a downlink power
like an incident downlink power spectral density. A preferred indicator is an unbiased
downlink power indicator like a received signal strength indicator RSSI or the like.
The development recognized that by measuring an unbiased received wide band power
within a band width of the communication user equipment receiver at the communication
user equipment antenna connector a basis is given to provide further information about
a jamming situation. In particular, by verifying the condition that the power indicator
is unchanged or has increased from the first time to the second time, the development
is able to provide the basis for making a statement about an in-call/connection jamming
situation. In particular, if the unbiased indicator changes significantly the statement
can be made.
[0037] In particular the indication can be given to an application layer of an evaluation
unit which interfaces to the user equipment. By means of the evaluation unit it is
possible to provide information discriminating between a jamming situation and an
out-of-coverage-situation. This kind of information can be signalized to a user. A
user can be a person or an automatic environment like an alarm or a supervision environment,
in particular in mobile entities like a car for instance. Thus, for instance a person
driving a car can be warned that at a certain location no alarm or supervision function
can be achieved by the user equipment be that it may be due to a jamming situation
or be that it may be due to an out-of-coverage situation. As follow-up the information
to the automatic or personalized periphery by means of the evaluation unit can be
used to provide further measures which are adapted to the kind of loss of service
availability. For instance other alarm or supervision functions can be activated.
For instance the situation can be used to save energy by cutting off a process which
is not of use in an out-of-coverage situation.
[0038] A power indicator is considered as any parameter significant for a power. This, of
course comprises a physically measurable power quantity itself, but also comprises
any other value which is of use to denote quantitatively the power quantity. In particular
the parameter not necessarily needs to have the metric unit of a power but can be
a dimensionless quantity, in particular a ratio or logarithmic or bit-value or other
value, which is suitable to quantitatively describe the physical power quantity.
[0039] In particular the meaning of power is to be understood broadly and also comprises
the meaning of energy. A preferred understanding of power is power spectral density
(PSD) according to the standard, whereas the units of Power Spectral Density (PSD)
are extensively and of broader use in this application. Generally a PSD is a function
of power versus frequency and when integrated across a given bandwidth (like a channel
e. g.); the function represents the mean power in such a bandwidth. When the mean
power is normalized to (divided by) the chip-rate it represents the mean energy per
chip. This is the common practice of relating power and energy or the like magnitudes
in communication systems. It can nevertheless be seen that if both energy magnitudes
in the ratio are divided by time, the ratio is converted from an energy ratio to a
power ratio, which is more useful from a measurement point of view. It follows that
an energy per chip of X dBm/200kHz can be expressed as a mean power per chip of X
dBm. Similarly, a signal PSD of Y dBm/200kHz can be expressed as a signal power of
Y dBm.
[0040] In a particular preferred development a radiolink error is identified with a single
radiolink irregularity or a sequence of irregularities e.g. two or three radiolink
irregularities, in particular low number of radiolink irregularities. Basically, a
radiolink error, in particular irregularity, can be measured by any suitable means.
For instance a radiolink irregularity can be measured by sending a testmessage or
another kind of radiolink-information item, either for test purposes only or also
using usual sending of other messages or another kind of radiolink-information item,
e. g. a paging message or a channel signal the like. Subsequently a missing receipt
or non-decodability of the testmessage or other message can be detected. Particular
preferred, a radiolink-failure identification is performed by:
- repeatingly decoding a radiolink-information item indicative of the connected mode
of the radiolink,
- scoring the able to decode and unable to decode incidence rate,
- indicating a radiolink error once an upper threshold of a radiolink timeout counter
or the like first early countermeasure is passed.
[0041] Preferably a radiolink error, e.g. a irregularity, can be indicated once a first
counter decrement, in particular a first counter-threshold is passed. In particular
a radiolink error can be indicated once the scoring-counter falls below the first
counter-threshold. In particular a radiolink-failure can be indicated once a second
counter-threshold is passed. Preferably a radiolink-failure can be indicated once
the scoring-counter falls below the second counter-threshold. The latest development
provides indicating a radiolink-failure once a limit second countermeasure is passed.
Thus, a radiolink-failure is identified due to a high number of radiolink irregularities.
[0042] Of course, also other scoring rules can be provided. However it has been considered
to be advantageous to provide a scoring rule, which can be easily implemented in a
standard; like for instance the technical specification GSM ETSI TS0508 chapter 5.
Therein, a particular preferred scoring-counter is described in form of a radiolink
timeout counter (RLT). Using the radiolink timeout counter is considered to be particular
advantageous for identifying a radiolink error and/or a radiolink-failure. In particular,
therein a radiolink-testmessage is a testmessage sent on a slow associated control
channel SACCH. Nevertheless, generally a radiolink-testmessage can also be a testmessage
on any control channel CCH. On the other hand --for detecting a jamming situation--
the instant development distinguishes basically from approaches using paging messages
on a PCH channel or another message on a TCH channel, as these are only suited to
serve as a basis in an idle mode, whereas the instant development is based on detecting
a jamming situation already in the connected mode of a radiolink.
[0043] The RLT counter based on the downlink SACCH in 3GPP ETSI TS05.08 is only one example
of a scoring-counter based on a control channel. Generally, as scoring-counter can
indicate a radiolink-failure once the scoring-counter falls below a counter threshold.
For instance, additionally the scoring-counter can be checked whether it decrements
or increments continuously. This is an advantageous further condition for safely indicating
a jamming situation. Generally, it is advisable to provide the radiolink error and/or
-failure identification based on an unable-to-decode incidence scoring negative and
an able-to-decode incidence rate scoring positive wherein the scoring-counter has
a positive start threshold and a counter threshold is zero.
[0044] Of course, also further regularities can be determined with a selected scoring rule.
For instance a strong indicator for an upcoming radiolink-failure, i. e. existing
radiolink error, is present in the case a consecutive sequence of radiolink-irregularity,
in particular a consecutive sequence of radiolink errors is determined. In this case
a radiolink timeout counter may not have reached a second threshold limit, but still
nevertheless the consecutive sequence can be sufficient to give a safe extrapolation,
that (and possibly also when) a radiolink-failure is to be expected. Thus providing
regularity with a scoring rule is advantageous to detect a radiolink-failure before
the radiolink-failure occurs, in particular before a second late countermeasure or
limit countermeasure is passed. E.g. a preferred embodiment as described with the
drawing can be used, wherein a lower and a upper threshold value of a radiolink timeout
counter serve as suitable countermeasures.
[0045] The instant concept and the developed configuration thereof are particularly advantageous
in a radio network based on a cellular global system for mobile communications. However,
nevertheless equivalent measures according to the concept can also be used in a CDMA
based radio network like an UMTS network for detecting an in-call/connection jamming
situation.
[0046] For a more complete understanding of the invention, the invention will now be described
in detail with reference to the accompanying drawing. The detailed description will
illustrate and describe what is considered as a preferred embodiment of the invention.
The invention is limited only by the appended claims. Any reference signs in the claims
shall not be construed as limiting the scope of the invention. The wording "comprising"
does not exclude other elements or steps. The wording "a" or "an" does exclude a plurality.
In the drawing:
[0047]
- Fig. 1:
- shows a flow chart for a first embodiment of a method of detecting a jamming transmitter
affecting a communication user equipment in course of a radiolink-failure;
- Fig. 2:
- shows a flow chart for a second embodiment of a method of detecting a jamming transmitter
affecting a communication user equipment in course of a radiolink error;
- Fig. 3:
- shows a flow chart for a further adapted second embodiment of a method of detecting
a jamming transmitter affecting a communication user equipment in course of a radiolink
error;
- Fig. 4:
- shows a preferred embodiment of a user equipment adapted to execute the method of
detecting a jamming transmitter affecting the communication user equipment as shown
in Fig. 1.
[0048] Fig. 1 shows a preferred embodiment of a method of detecting a jamming transmitter
affecting a communication user equipment wherein the user equipment is activated in
step S1, namely by switching on the user equipment to an active-status. In step S2
the user equipment is registering in the radio network, which in the present case
is a GSM network (global systems for mobile communication). As described in the standard,
thereafter the user equipment will approach from the out of service situation after
registering to the idle mode in step S3, wherein the user equipment is switched on
but has not yet a dedicated channel allocated. Thus, in the idle mode in step S3,
the user equipment is able to make or receive a call but does not have an active call.
In step S4 a call establishment is done, i.e. the user equipment receives or originates
a call and once parameters are made as outlined in 3GPP TS45.008, the communication
module will approach to the connected mode in step S5; then the communication module
will have an active call on a dedicated channel, which has been allocated during step
S4. For technical systems like security systems, wherein signals, e. g. camera data
or the like, are transmitted by means of a communication module in the system, the
signals can be transmitted in the dedicated connection or channel of the connected
mode of the communication radiolink.
[0049] The further flow chart indicates measures, which can steadily be provided in a predetermined
time sequence or loop by the communication module. For better illustration, in the
instant example the measures are described for a process of a jamming situation, wherein
a jamming signal J is affecting the user equipment UE. In the instant embodiment in
a predetermined time sequence a power indicator --here the so called received signal
strength indicator RSSI-- is measured as an early power indicator and is determining
at a first time t1 as a received wide band radio signal strength over the radio frequency
band width of the antenna of the communication user equipment. Here, the early power
indicator RSSI-t1 in step S6 is determined at the first time t1; thus well before
in step S8 a radiolink-failure identification happens, due to the continued jamming
action indicated along with step S7.
[0050] The received signal strength indicator RSSI measured at the first time t1 to determine
the early power indicator RSSI-t1 can be stored or held by any suitable means as the
early power indicator. Thus the early power indicator is available for later on comparison
and contains a received signal strength indicator RSSI measured for an undisturbed
situation of the user equipment at the first time t1.
[0051] The radiolink-failure identification in step S8 of the instant embodiment is prepared
by decrementing --due to the jamming signal J-- a radiolink timeout counter RLT. The
radiolink timeout counter RLT is decremented continuously from a maximum value MAX
to or below a counter-threshold, which is referenced by a value 0. Thus, in particular,
as described in GSM ETSI TS05.08 chapter 5.2, here due to the jamming signal J the
mobile station will be unable to decode a SACCH message and thus, the scoring counter
in form of the radiolink timeout counter RLT is decreased by a value of 1 (in this
case a parameter of Bad Frame Indication BFI=1; SACCH stands for Slow Associated Control
Channel). In the case of a successful caption (not the case here) of a test message
in form of a SACCH message (Bad Frame Indication BFI=0) the radiolink timeout counter
RLT value S is increased by a value of 2. In any case the radiolink timeout counter
shall not exceed the value of low radiolink timeout which is S=0. If, however, the
radiolink timeout counter RLT reaches S=0 or is even below 0 a radiolink-failure is
indicated in step S8. Additionally, in this embodiment, the condition is checked whether
the radiolink timeout counter RLT has been decremented continuously; it is further
checked whether a parameter "cont" is positive. This advantageously allows preventing
instrument errors and excludes detection alarms which merely arise from a swaying
radiolink situation. Thus in the present embodiment the radiolink-failure identification
reliably is established by a radiolink timeout counter RLT with a value S equal to
or below 0 and a positive parameter "cont". A further action can be specified as described
in GSM ETSI TS04.18 and the radiolink timeout parameter can be transmitted by each
BSS (Base Station System) in the data of the BCCH (Broadcast Control Channel) and
the mobile station MS or other kind of user equipment UE shall continue transmitting
as normal on the uplink until the value S reaches 0. The algorithm of a further action
shall start after the assignment of a dedicated channel and the value S shall be initialized
to a value of the radiolink timeout counter. The detailed operation is outlined in
GSM ETSI TS05.08 chapter 5.2. This is the case for the NO-path N1 starting from step
S8 and the NO-path N2 starting from step S10.
[0052] However, in the present case --in step S9 following the YES-path Y1-- a further determination
of a later power indicator RSSI-t2 at a second time t2 after the radiolink-failure
identification in step S8 is performed. Thus, two power indicators are available;
an early power indicator RSSI-t1 from step S6 --not influenced by the jamming signal
J-- and a later power indicator RSSI-t2 from step S9 --influenced by the jamming signal
J--. In step S10 the further condition is verified whether the received wide band
radio signal strength RSSI is unchanged or has increased from the first time t1 to
the second time t2. In the present case it is sufficient to compare the RSSI values
RSSI-1t1 and RSSI-t2, namely the early power indicator RSSI-t1 and the later power
indicator RSSI-t2 directly. In the case that in step S10 the later power indicator
RSSI-t2 is greater or equal to RSSI-t1, a jamming situation is indicated in step S11.
The jamming situation JAM can be indicated to an application APP in step S12. Thus,
even in the case that a connected mode shall already be interrupted by the jammer
due to the jamming signal J (as described here) --still nevertheless-- a messaging
by a software-interface or the like is possible to an application APP informing about
the jamming situation JAM. Thus, warnings about the jamming situation JAM can be given
from another side of a higher system. A user or supervisor of the higher system level
can be warned by the messaging in that jamming occurs and that a correct functioning
of a security system cannot be guaranteed.
[0053] It should be recognized that in the present embodiment for the radiolink evaluation
primarily it is evaluated whether the communication radiolink is affected by a radiolink-failure,
wherein a radiolink-failure identification is identified due to a fully decremented
radiolink timeout counter RLT to a minimum value S=0 at least.
[0054] However, --as is exemplified in Fig. 2-- in an elaborated further developed embodiment
for the method it can be evaluated whether the communication radiolink is affected
by a radiolink-irregularity, wherein a radiolink-irregularity identification is identified
due to a radiolink timeout counter RLT decremented below a lower threshold value S=LOW,
which is above the aforementioned minimum value S=0. The lower threshold value can
be defined such that the lower threshold value S=LOW is below an upper threshold value
S=UP. In particular the communication user equipment UE can be assumed to be undisturbed,
in the case a radiolink timeout counter RLT has a value S above an upper threshold
value S=UP, which nevertheless is below a maximum value S=MAX. It turned out, that
is advantageous to provide such kind of smooth threshold values apart from the minimum
and maximum values, such that an early jamming evaluation or warning can be provided.
The upper threshold value S=UP and the lower threshold value S=LOW or other kind of
smooth threshold values of the radiolink timeout counter can be adapted e.g. due to
a statistical analysis of radiolink signals or operational situations adapted to the
instant location and surrounding of the user equipment (UE).
[0055] Fig. 2 shows a more elaborated exemplifying embodiment of a method of detecting a
jamming transmitter affecting a communication user equipment UE in course of one or
more radiolink-irregularities, preferably wherein a radiolink-irregularity is identified
due to a broken block and/or broken link and/or a fully decremented timeout counter
identifies a radiolink-failure. In these and other cases --depending on a specific
setting a radiolink error is identified due to a jamming signal J.
[0056] The more elaborated second embodiment of a method of Fig. 2 starts in a first step
SE1 wherein the user equipment UE is in a connected mode. In a subsequent step SE2
the radiolink timeout counter RLT is set to its maximum value MAX. As an instant follow-up
in step SE3 one can be sure that the RLT counter indeed has the maximum value S=MAX.
A power indicator parameter --here an RSSI-value RSSI-t1 at a first earlier point
of time t1-- is acquired and hold; for instance by storing in a storing medium of
or connected to a communication module in the user equipment UE. A measurement or
other setting of a power indicator parameter in exceptional situations can be affordable
even when the RLT counter has not the maximum value S=MAX, but is e.g. at least above
a value above an upper threshold value S=UP. Nevertheless it should be avoided to
set a power indicator parameter when the RLT counter has not the maximum value S=MAX.
This makes sure that the first earlier power indicator RSSI-t1 is taken preferably
in an undisturbed state of the user equipment UE. At least this assures that the comparative
value of an RSSI power indicator is at a sufficient high level to be compared to a
later power indicator RSSI-t2 determined at the later second time t2. In particular
the communication user equipment UE can be assumed to be less disturbed, --at least
in a smoothed setting-- in the case a radiolink timeout counter RLT has a value S
above an upper threshold value S=UP, which nevertheless is below a maximum value S=MAX.
Also recognition that a radiolink timeout counter RLT has a value S above an upper
threshold value S=UP can be used to suppress signaling of a jamming warning due to
the assumption that as soon as S is above an upper threshold value S=UP a warning
is to be considered as too early in the specific situation.
[0057] At this early point of first time t1 with preferably S=MAX or at least S> UP --important
for a later stadium of the method-- the further procedural sequence is followed up
by step SE4 directly, namely by evaluating the radiolink; e.g. by sending a test message
on the SACCH as described above. In the case such or another predefined kind of radiolink
irregularity is acknowledged during radiolink evaluation in step SE4 a radiolink error
can be indicated in step S5. It should be recognized that the radiolink-failure described
with the embodiment of Fig.1 is only one exemplifying item of a radiolink irregularity,
which --of course can also be define to be of minor severity. Generally a radiolink
error identification in step SE5 thus is possible on basis of any radiolink irregularity
according to the general part of these application documents, in particular well before
a radiolink-failure is detected as outlined in the above description of Fig. 1.
[0058] Here, as a follow-up of a radiolink irregularity in the YES-path YE1 the RLT counter
is decremented in step SE6. At the second later point of time t2 the further later
power indicator RSSI is measured in step SE7 as RSSI-t2. This procedure makes sure
that the later power indicator RSSI-t2 at the second point of time t2 is measured
already in a rather early stadium of radiolink irregularity, namely already just after
the occurrence of a first radiolink-irregularity. In particular --at least in a smoothed
setting-- a radiolink-irregularity identification is identified due to a radiolink
timeout counter RLT decremented below a lower threshold value S=LOW, which is above
the aforementioned minimum value S=0. The lower threshold value can be defined such
that the lower threshold value S=LOW is below an upper threshold value S=UP.
[0059] Thus, according to the developed further elaborated method shown in Fig. 2 the sequence
of steps SE5, SE6 and SE7 makes sure that an early jamming evaluation warning of Step
SE16 is possible already right after the occurrence of a first radiolink irregularity.
Thus, here a radiolink error is specified according to a rather sensitive setting,
namely any radiolink irregularity, in particular arising from a failure to receipt
a sent test message on a SACCH. In case of an RSSI-t2-value exceeding an RSSI-t1-value
in step SE8 an early jamming evaluation can be given in step SE9 well before a totally
broken connection due to a radiolink-failure as described with Fig.1 wherein the radiolink
timeout counter already has reached the value S=0.
[0060] Consequently as compared to the method shown in Fig. 1 the instant elaborated method
is able to provide an early jamming warning following the step SE9 and SE16 well before
a totally broken connection and thus earlier than the embodiment described in Fig.
1.
[0061] In particular if a sequence of RLT counter decrements is evaluated by the "Early
Jamming Detection" in SE9 a more reliable Early Jamming warning level and/or state
will result.
[0062] Consequently if after RLT counter being decremented one RLT counter increment or
a sequence of RLT counter increments is evaluated in SE9 the Early Jamming warning
level can be decreased and/or the warning state can be switched off.
[0063] In the alternative in step SE5 a radiolink error is not indicated (NO-path NE1) the
radiolink timeout counter RLT is incremented in step SE10. Thereafter in step SE11
it is verified further whether the RLT counter value is below a maximum value S<MAX.
In the positive case (YES-path, YE2) the procedure further follows step SE7 as described
above. This means the procedure of checking a RSSI power indicator at a later point
of time t2 continues until the RLT counter value reaches again the maximum value S=MAX
or --at least in a smoothed setting-- reaches the upper threshold value S=UP. Thus,
Early Jamming Evaluation in step SE9.is continued until it can be safely assumed that
no radiolink irregularity exists. Otherwise following the further NO-path NE2 the
radiolink timeout counter RLT is set to its maximum value MAX. As a consequence of
this continued assessment an early jamming evaluation will be indicated and given
as a warning to the user of a user equipment UE until it can be safely assumed that
every radiolink irregularity is omitted; thus until it can be safely assumed that
no jamming action occurs anymore.
[0064] In the case in step SE12 the RLT counter value exceeds a minimum value --here the
lowest threshold value of S=0 or at least in a smoothed setting reaches the lower
threshold value S=LOW also the instant procedure makes sure that an evaluation of
a radiolink irregularity continues further with the sequence starting from step SE4
following the YES-path YE3.
[0065] In the alternative in the NO-path NE3 proceeding from step SE12 a broken connection
will be indicated in step SE13 and given as an indication of a jamming situation JAM
to the user of a user equipment UE. Also, once the RLT counter value is equal to or
below 0, an OOS warning can be given in step SE15.
[0066] The instant procedural steps can be performed by a module itself in user equipment
itself, wherein an application APP in step SE14 is integrated into the module. Also
the application layer can be interfaced to the module in the user equipment UE. The
application APP can gather further information and parameters to rate the instant
situation; thus is also capable to further modify the indication of a broken connection.
Also the application APP is in receipt of an out-of-service warning OOS as depicted
in step SE15 and a Jamming warning as depicted in step SE16.
[0067] Fig. 3 describes in more detail what has been indicated before as an embodiment of
smoothed setting. A particular preferred further extension of the procedure described
with the second embodiment of Fig. 2 can be switched-in between junction items J1
following step SE7 and J2 before step SE12 as depicted in the flow chart of Fig. 2.
The extension is preferably used to define application and usage dependent threshold
criteria for very early indication of a radiolink error; which is also denoted as
a jamming warning. Follow-up junction J1 in step SJ1 various threshold criteria can
be defined. For instance it can be defined that a radiolink error is indicated only
in the case the RLT counter decrements below a certain first threshold value Y. Here
a number of RLT counter values S=RLT1 ..RLTi..RLTn ; i=1-n are defined in Y.
[0068] As a follow-up the early jamming warning of step SE9 is given only in the case the
RLT counter has been decremented in step SE6 below the specified threshold value Y.
Alternatively or additionally a number X of radiolink irregularities can be specified
which define a consecutive sequence of one after the other radiolink irregularities.
Here a number of RSSI-t2 values S= RSSI-t2_1.. RSSI-t2_i.. RSSI-t2_n ; i=1-n can be
specified. Thus, only in the case a consecutive sequence of for instance a number
of X=3..5 radiolink irregularities occurrences in step SE6 lead to an indication of
an early jamming warning of step SE9 as indicated.
[0069] Thus, dependent on the definition of threshold criteria in step SJ1 the conditions
given in step SJ3 and SJ2 are checked. In case an analysis of an RLT irregularity
is of sufficiently severe result in step SJ3 the further procedure can reveal in step
SJ2 that the RSSI-t2-value exceeds the RSSI-t1-value. In this case a jamming probability
of step SJ4 can be given in step SJ5 --dependent on the severity of the threshold
criteria defined in steps SJ3 and SJ2-- in the YES-path YJ1; otherwise in the case
the condition is not fulfilled only a bad radiolink indication is given in step SJ6,
in particular step SJ6 can also indicate an out-of-coverage-situation to the user
if for example RSSI-t2 < RSSI-t1. A jamming probability indication result of step
SJ4 can be given additionally to or alternatively to an early jamming evaluation of
step SE9 of the procedure in Fig. 2.
[0070] Consequently a user of the user equipment UE can receive in an elaborated situation
not only an early jamming evaluation indication from step SE9 but also an indication
of probability of jamming as produced from step SJ7.
[0071] In a preferred embodiment the jamming probability and the early jamming evaluation
of steps SJ4 and/or SE9 respectively can be given to an application APP, in particular
an application layer 10 as shown in Fig.4. In this case the application layer primarily
is adapted to provide further measures like e.g. provide signalling options for giving
a jamming indication and/or warning to a user or other layers of a communication system
and/or network. In the application layer 10 further measures as follow-up action can
be evaluated to be taken or signalized to a user or connected items of the user equipment.
Thus in the periphery of the user equipment not only a early jamming evaluation is
available but also a probability of jamming so that counter action can be taken at
a very early stage of jamming and still usually in a connected mode condition of the
user equipment. This situation is depicted by the application layer 10 and user equipment
1.
[0072] In the case the condition checked in step SJ2 is not fulfilled the supplement of
the extended procedure is followed to the junction point J2 and continued with step
SE12 shown in Fig. 2. Also, if the RSSI-t2-value does not exceed the RSSI-t1-value
(NO-path of step SJ3) in-between indication to the user of step SJ5 is suppressed
for instance before continuing with junction J2 as outlined above. Thus, in the supplement
between junction items J1 and J2 the user receives a bad radiolink warning as long
the RLT counter value is above a minimum or low threshold in step SE12.
[0073] In Fig. 4 a user equipment UE is shown wherein a communication module 1, 1' and a
connected application layer 10, 10' is provided in the user equipment UE. The communication
module 1, 1' is connected via an antenna 11 thus a received wide band radio signal
strength can be measured by a power indicator 2 of the communication module. In the
present case the power indicator 2 will provide an RSSI value taking into account
not only the usual network signal strength but also a strength of the jamming signal
J.
[0074] Further a radiolink timeout module 3 is provided, capable of executing the step S7
of the method described in Fig. 1 or similar step SE6 as shown in Fig. 2 and Fig.
3 in the case an early jamming indication is preferred. The radiolink timeout module
3 and the power indicator 2 are started repeatedly for determining the power indicator
RSSI; a radiolink-failure evaluation is triggered by a clock 4 or the like sequencing
unit.
[0075] The following procedural steps of comparator 5 and unit 6 can be implemented in module
1. In this case, a jamming indication of step S11 can be given to an application 7
connected to the module 1. However, also the module 1' can be adapted only to provide
the output of radiolink timeout module 3 and power indicator 2 to an application layer
10'; thus the application layer 10' can be adapted to provide the procedural steps
of comparator 5 and unit 6.
[0076] Here, once a zero value S of the RLT counter (i. e. generally a counter threshold
of the scoring-counter) is achieved, a comparator 5 is triggered for comparing an
early power indicator at a first time t1 and a later power indicator at a second time
t2. The difference thereof is provided to an evaluation unit 6 for processing the
step S10 of the method of Fig. 1. In the case the result is positive, it can be assumed
that the received wide band radio signal strength is unchanged or has increased from
the first time t1 to the second time t2.
[0077] Thus, the user of the user equipment UE can be warned of the jamming situation.
1. Method of detecting a jamming transmitter affecting a communication user equipment
(UE),
wherein said communication user equipment (UE), having a communication module (1),
is adapted for communication with a component of a radio network based on a cellular
global system for mobile communications, having a number of user equipments (UE) and
a number of base stations, wherein said method comprises
- providing the user equipment (UE) in a connected mode of a communication radiolink
with the component of the radio network; wherein in the connected mode of said user
equipment (UE) the steps are provided:
- setting an early power indicator (RSSI-t1) determined at a first time indicative
of a received radio signal strength, wherein the early power indicator set is assumed
for a state of the user equipment (UE) unaffected by a radiolink error, wherein setting
the early power indicator is executed by measuring the early power indicator determined
at the first time, indicative of a received radio signal strength;
- providing a radiolink evaluation, evaluating whether the communication radiolink
is affected by a radiolink error, and wherein it is verified that a scoring-counter
is changed due to a number of radiolink-irregularities to identify a radiolink failure,
and
- in case of a radiolink error identification performing the following steps:
- determining a later power indicator (RSSI-t2) at a second time indicative of a received
radio signal strength, wherein the later power indicator determined is defined for
a state affected by a radiolink error of the user equipment (UE);
- comparing the early power indicator (RSSI-t1) from the first time to the later power
indicator (RSSI-t2) from the second time, and
- indicating a jamming affection in case the comparison shows that the received radio
signal strength is unchanged or has increased.
2. Method according to claim 1 wherein the received radio signal strength is a received
wide band radio signal strength over the used radiofrequency of the communication
module (1) of the communication user equipment (UE), and wherein the power indicator
is an indicator for a downlink power.
3. Method according to any of the claims 1 to 2 wherein the early power indicator is
compared to the later power indicator wherein the first time is before a radiolink
evaluation and the second time is during or after the radiolink error identification.
4. Method according to any of the claims 1 to 3 wherein the power indicator determination
and the radiolink error evaluation in combination are repeated in a predetermined
time sequence.
5. Method according to any of the claims 1 to 4 wherein a radiolink error is identified
due to at least one radiolink-irregularity, wherein a radiolink irregularity is identified
due to a broken block and/or broken link and/or a partially changed radiolink timeout
counter (RLT).
6. Method according to any of the claims 1 to 5 wherein to provide the radiolink evaluation
it is evaluated whether the communication radiolink is affected by a radiolink-failure,
wherein a radiolink-failure identification is identified due to the scoring-counter
decremented to a minimum value.
7. Method according to claim 6 wherein the communication user equipment (UE) is assumed
to be undisturbed in the case the scoring-counter has a value above an upper threshold
value, which is below a maximum value.
8. Method according to any of the claims 1 to 7 wherein to provide the radiolink evaluation
it is evaluated whether the communication radiolink is affected by a radiolink-irregularity,
wherein a radiolink-irregularity identification is identified due to the scoring-counter,
decremented below a lower threshold value, which is above a minimum value, and wherein
the lower threshold value is below an upper threshold value.
9. Method according to any of the claims 1 to 8 wherein a radiolink-failure identification
is performed by:
- repeatingly decoding a radiolink-information item indicative of the connected mode
of the radiolink;
- scoring an able-to-decode incidence rate and/or an unable-to-decode incidence rate
for a number of radiolink information items on the scoring-counter,
- indicating a radiolink error once a disturbed decoding is registered, the disturbed
decoding being out of a group comprising an erroneous radiolink-information item reception
or erroneous link- or block-error.
10. Method according to claim 9 wherein the unable-to-decode incidence rate scores negative
and the able-to-decode incidence rate scores positive and wherein the scoring-counter
has a positive start-threshold and a counter-threshold is zero.
11. Method according to any of the claims 9 and 10 wherein the radiolink-information item
is a radiolink-testmessage transmitted on a control channel.
12. Method according to any of the claims 1 to 11 wherein a jamming affection is indicated
to an application layer (10) interfaced to and/or integrated in the communication
module (1).
13. System of a communication module (1) and an application layer (10), being part of
a communication user equipment (UE), the system being adapted to execute the method
of detecting a jamming transmitter affecting the communication user equipment (UE)
as claimed in any of the preceding claims, and wherein the application layer (10)
is integrated in the communication module (1) or is interfaced to the communication
module (1).
14. System of claim 13, wherein the communication module (1) has one or more means for
providing the following step in the connected mode of said user equipment (UE): submitting
a radiolink error signal and the early power indicator (RSSI-t1) determined at the
first time and the later power indicator (RSSI-t2) determined at the second time,
to the application layer.
15. System of claim 13, wherein the application layer (10) is adapted to provide the following
steps in case of a radiolink error identification:
- the early power indicator (RSSI-t1) determined at the first time is compared to
the later power indicator (RSSI-t2) determined at the second time, and determined
after the radiolink error identification.
- a jamming affection is indicated in case the comparison shows that the received
wide band radio signal strength is unchanged or has increased from the first time
to the second time.
1. Verfahren zur Erkennung eines Störsenders, der ein Kommunikationsbenutzergerät (UE)
beeinflusst, wobei das Kommunikationsbenutzergerät (UE) mit einem Kommunikationsmodul
(1) zur Kommunikation mit einer Komponente eines Funknetzes auf der Grundlage eines
globalen zellularen Systems für Mobilkommunikation mit einer Anzahl von Benutzergeräten
(UE) und einer Anzahl von Basisstationen ausgelegt ist, wobei das Verfahren umfasst:
- Bereitstellen des Benutzergeräts (UE) in einem verbundenen Modus einer Kommunikationsfunkverbindung
mit der Komponente des Funknetzes; wobei im verbundenen Modus des Benutzergeräts (UE)
die folgenden Schritte bereitgestellt werden:
- Setzen eines frühen Leistungsindikators (RSSI-t1), der zu einem ersten Zeitpunkt
bestimmt wird und eine Funkempfangssignalstärke anzeigt, wobei der frühe Leistungsindikatorsatz
für einen Zustand des Benutzergeräts (UE) angenommen wird, der nicht von einem Funkverbindungsfehler
beeinflusst wird, wobei das Setzen des frühen Leistungsindikator durch Messen des
zum ersten Zeitpunkt bestimmten frühen Leistungsindikators ausgeführt wird, der eine
Funkempfangssignalstärke anzeigt;
- Bereitstellen einer Funkverbindungsbeurteilung, Beurteilen, ob die Kommunikationsfunkverbindung
von einem Funkverbindungsfehler beeinflusst wird, und worin verifiziert wird, dass
ein Bewertungszähler aufgrund einer Anzahl von Funkverbindungsunregelmäßigkeiten geändert
wird, um einen Funkverbindungsfehler zu identifizieren, und
- Ausführen der folgenden Schritte im Falle einer Funkverbindungsfehleridentifizierung:
- Bestimmen eines späteren Leistungsindikators (RSSI-t2) zu einem zweiten Zeitpunkt,
der eine Funkempfangssignalstärke anzeigt, wobei der bestimmte spätere Leistungsindikator
für einen Zustand definiert ist, der von einem Funkverbindungsfehler des Benutzergeräts
(UE) beeinflusst wird;
- Vergleichen des frühen Leistungsindikators (RSSI-t1) vom ersten Zeitpunkt mit dem
späteren Leistungsindikator (RSSI-t2) vom zweiten Zeitpunkt, und
- Anzeigen einer Störneigung, falls der Vergleich zeigt, dass die Funkempfangssignalstärke
unverändert ist oder sich erhöht hat.
2. Verfahren nach Anspruch 1, wobei die Funkempfangssignalstärke eine Breitband-Funkempfangssignalstärke
über die verwendete Funkfrequenz des Kommunikationsmoduls (1) des Kommunikationsbenutzergeräts
(UE) ist, und wobei der Leistungsindikator ein Indikator für eine Downlink-Leistung
ist.
3. Verfahren nach einem der Ansprüche 1 bis 2, wobei der frühe Leistungsindikator mit
dem späteren Leistungsindikator verglichen wird, wobei der erste Zeitpunkt vor einer
Funkverbindungsbeurteilung ist, und der zweite Zeitpunkt während oder nach der Funkverbindungsfehleridentifizierung
ist.
4. Verfahren nach einem der Ansprüche 1 bis 3, wobei die Leistungsindikatorbestimmung
und die Funkverbindungsfehlerbeurteilung in Kombination in einer vorbestimmten Zeitfolge
wiederholt werden.
5. Verfahren nach einem der Ansprüche 1 bis 4, wobei ein Funkverbindungsfehler aufgrund
mindestens einer Funkverbindungsunregelmäßigkeit identifiziert wird, wobei eine Funkverbindungsunregelmäßigkeit
aufgrund eines unterbrochenen Blocks und/oder einer unterbrochenen Verbindung und/oder
eines teilweise geänderten Funkverbindungs-Timeout-Zählers (RLT) identifiziert wird.
6. Verfahren nach einem der Ansprüche 1 bis 5, wobei zur Bereitstellung der Funkverbindungsbeurteilung
beurteilt wird, ob die Kommunikationsfunkverbindung von einem Funkverbindungsausfall
beeinflusst wird, wobei eine Funkverbindungsausfallidentifizierung aufgrund des auf
einen Minimalwert dekrementierten Bewertungszählers identifiziert wird.
7. Verfahren nach Anspruch 6, wobei angenommen wird, dass das Kommunikationsbenutzergerät
(UE) ungestört ist, falls der Bewertungszähler einen Wert über einem oberen Schwellenwert
hat, der unter einem Höchstwert liegt.
8. Verfahren nach einem der Ansprüche 1 bis 7, wobei zur Bereitstellung der Funkverbindungsbeurteilung
beurteilt wird, ob die Kommunikationsfunkverbindung von einer Funkverbindungsunregelmäßigkeit
beeinflusst wird, wobei eine Funkverbindungsunregelmäßigkeitsidentifizierung aufgrund
dessen identifiziert wird, dass der Bewertungszähler unter einen unteren Schwellwert
dekrementiert ist, der über einem Mindestwert liegt, und wobei der untere Schwellwert
unter einem oberen Schwellwert liegt.
9. Verfahren nach einem der Ansprüche 1 bis 8, wobei eine
Funkverbindungsausfallidentifizierung durchgeführt wird durch:
- wiederholtes Decodieren eines Funkverbindungsinformationselements, das den verbundenen
Modus der Funkverbindung anzeigt;
- Bewerten einer decodierfähigen Inzidenzrate und/oder einer nicht-decodierfähigen
Inzidenzrate für eine Anzahl von Funkverbindungsinformationen auf dem Bewertungszähler,
- Anzeigen eines Funkverbindungsfehlers, sobald eine gestörte Decodierung registriert
wird, wobei die gestörte Decodierung außerhalb einer Gruppe liegt, die einen fehlerhaften
Empfang eines Funkverbindungsinformationselements oder einen fehlerhaften Verbindungs-
oder Blockfehler umfasst.
10. Verfahren nach Anspruch 9, wobei die nicht-decodierfähige Inzidenzrate negativ bewertet
wird und die decodierfähige Inzidenzrate positiv bewertet wird, und wobei der Bewertungszähler
einen positiven Startschwellenwert hat, und ein Zählerschwellenwert null ist.
11. Verfahren nach einem der Ansprüche 9 und 10, wobei das
Funkverbindungsinformationselement eine auf einem Steuerkanal übertragene Funkverbindungs-Testnachricht
ist.
12. Verfahren nach einem der Ansprüche 1 bis 11, wobei eine Störneigung einer Anwendungsschicht
(10) angezeigt wird, die über eine Schnittstelle mit dem Kommunikationsmodul (1) verbunden
und/oder darin integriert ist.
13. System aus einem Kommunikationsmodul (1) und einer Anwendungsschicht (10), die Teil
eines Kommunikationsteilnehmergeräts (UE) sind, wobei das System angepasst ist, um
das Verfahren zur Erkennung eines das Kommunikationsteilnehmergerät (UE) beeinflussenden
Störsenders nach einem der vorhergehenden Ansprüche auszuführen, und wobei die Anwendungsschicht
(10) in das Kommunikationsmodul (1) integriert ist oder über eine Schnittstelle mit
dem Kommunikationsmodul (1) verbunden ist.
14. System nach Anspruch 13, wobei das Kommunikationsmodul (1) ein oder mehrere Mittel
zum Bereitstellen des folgenden Schrittes im verbundenen Modus des Benutzergeräts
(UE) aufweist:
- Senden eines Funkverbindungsfehlersignals und des zum ersten Zeitpunkt bestimmten
frühen Leistungsindikators (RSSI-t1) und des zum zweiten Zeitpunkt bestimmten späteren
Leistungsindikators (RSSI-t2) an die Anwendungsschicht.
15. System nach Anspruch 13, wobei die Anwendungsschicht (10) angepasst ist, um im Falle
einer Funkverbindungsfehleridentifizierung die folgenden Schritte bereitzustellen:
- Der zum ersten Zeitpunkt bestimmte frühe Leistungsindikator (RSSI-t1) wird mit dem
zum zweiten Zeitpunkt bestimmten späteren Leistungsindikator (RSSI-t2) verglichen
und nach der Funkverbindungsfehlererkennung bestimmt.
- Eine Störneigung wird angezeigt, falls der Vergleich zeigt, dass die Breitband-Funkempfangssignalstärke
unverändert ist oder sich vom ersten Zeitpunkt zum zweiten Zeitpunkt erhöht hat.
1. Procédé de détection d'un émetteur de brouillage affectant un équipement utilisateur
(UE) de communication, dans lequel ledit équipement utilisateur (UE) de communication,
comportant un module de communication (1), est adapté à communiquer avec un composant
d'un réseau radio basé sur un système cellulaire mondial de communications mobiles,
ayant un certain nombre d'équipements utilisateur (UE) et un certain nombre de stations
de base, ledit procédé comprenant
- la mise de l'équipement utilisateur (UE) dans un mode connecté d'une liaison radio
de communication avec le composant du réseau radio ; dans le mode connecté dudit équipement
utilisateur (UE), les étapes étant les suivantes :
- la définition d'un indicateur de puissance précoce (RSSI-t1) déterminé à un premier
temps indiquant une intensité de signal radio reçu, l'indicateur de puissance précoce
défini étant supposé être pour un état de l'équipement utilisateur (UE) non affecté
par une erreur de liaison radio, la définition de l'indicateur de puissance précoce
étant exécutée par mesure de l'indicateur de puissance précoce déterminé dans le premier
temps, indiquant une intensité de signal radio reçu ;
- la fourniture d'une évaluation de liaison radio, évaluant si la liaison radio de
communication est affectée par une erreur de liaison radio, et dans lequel il est
vérifié qu'un compteur de notation est modifié en raison d'un certain nombre d'irrégularités
de liaison radio pour identifier une défaillance de liaison radio, et
- en cas d'identification d'erreur de liaison radio, l'exécution des étapes suivantes
:
- la détermination d'un indicateur de puissance ultérieur (RSSI-t2) à un second temps
indiquant une intensité de signal radio reçu, l'indicateur de puissance ultérieur
déterminé étant défini pour un état affecté par une erreur de liaison radio de l'équipement
utilisateur (UE) ;
- la comparaison de l'indicateur de puissance précoce (RSSI-t1) du premier temps à
l'indicateur de puissance ultérieur (RSSI-t2) du second temps, et
- l'indication d'une affection de brouillage dans le cas où la comparaison montre
que l'intensité du signal radio reçu est inchangée ou a augmenté.
2. Procédé selon la revendication 1, dans lequel l'intensité du signal radio reçu est
une intensité du signal radio large bande reçu sur la radiofréquence utilisée du module
de communication (1) de l'équipement utilisateur (UE) de communication, et dans lequel
l'indicateur de puissance est un indicateur pour une puissance de liaison descendante.
3. Procédé selon l'une quelconque des revendications 1 à 2, dans lequel l'indicateur
de puissance précoce est comparé à l'indicateur de puissance ultérieur, dans lequel
le premier temps est avant une évaluation de liaison radio et le second temps est
pendant ou après l'identification d'erreur de liaison radio.
4. Procédé selon l'une quelconque des revendications 1 à 3, dans lequel la détermination
d'indicateur de puissance en association avec l'évaluation d'erreur de liaison radio
sont répétées dans une séquence temporelle prédéterminée.
5. Procédé selon l'une quelconque des revendications 1 à 4, dans lequel une erreur de
liaison radio est identifiée en raison d'au moins une irrégularité de liaison radio,
dans lequel une irrégularité de liaison radio est identifiée en raison d'un bloc rompu
et/ou d'une liaison interrompue et/ou d'un compteur de temporisation de liaison radio
(RLT) partiellement modifié.
6. Procédé selon l'une quelconque des revendications 1 à 5, dans lequel pour fournir
l'évaluation de liaison radio, il est évalué si la liaison radio de communication
est affectée par une défaillance de liaison radio, dans lequel une identification
de défaillance de liaison radio est identifiée en raison du compteur de notation décrémenté
à une valeur minimale.
7. Procédé selon la revendication 6, dans lequel l'équipement utilisateur (UE) de communication
est supposé être non perturbé ns le cas où le compteur de notation a une valeur supérieure
à une valeur de seuil supérieure, qui est inférieure à une valeur maximale.
8. Procédé selon l'une quelconque des revendications 1 à 7, dans lequel pour fournir
l'évaluation de liaison radio, il est évalué si la liaison radio de communication
est affectée par une irrégularité de liaison radio, dans lequel une identification
d'irrégularité de liaison radio est identifiée en raison du compteur de notation,
décrémentée en dessous d'une valeur de seuil inférieure, qui est supérieure à une
valeur minimale, et dans lequel la valeur de seuil inférieure est inférieure à une
valeur de seuil supérieure.
9. Procédé selon l'une quelconque des revendications 1 à 8, dans lequel une identification
de défaillance de liaison radio est effectuée par :
- décodage répété d'un élément d'information de liaison radio indiquant le mode connecté
de la liaison radio ;
- notation d'un taux d'incidence apte-à-décoder et/ou d'un taux d'incidence non-apte-à-décoder
pour un certain nombre d'informations de liaison radio sur le compteur de notation,
- indication d'une erreur de liaison radio une fois qu'un décodage perturbé est enregistré,
le décodage perturbé étant en dehors d'un groupe comprenant une erreur de réception
d'élément d'information de liaison radio ou une erreur de liaison ou une erreur de
bloc.
10. Procédé selon la revendication 9, dans lequel le taux d'incidence non-apte-à-décoder
est négatif et le taux d'incidence apte-à-décoder est positif et dans lequel le compteur
de notation a un seuil de départ positif et un seuil de compteur est nul.
11. Procédé selon l'une quelconque des revendications 9 et 10, dans lequel l'élément d'information
de liaison radio est un message de test de liaison radio transmis sur un canal de
commande.
12. Procédé selon l'une quelconque des revendications 1 à 11, dans lequel une affection
de brouillage est signalée à une couche d'application (10) en interface avec et/ou
intégrée dans le module de communication (1).
13. Système d'un module de communication (1) et d'une couche d'application (10), faisant
partie d'un équipement utilisateur (UE) de communication, le système étant adapté
pour exécuter le procédé de détection d'un émetteur de brouillage affectant l'équipement
utilisateur (UE) de communication selon l'une quelconque des revendications précédentes,
et dans lequel la couche d'application (10) est intégrée dans le module de communication
(1) ou est en interface avec le module de communication (1).
14. Système selon la revendication 13, dans lequel le module de communication (1) a un
ou plusieurs moyens pour fournir l'étape suivante dans le mode connecté dudit équipement
utilisateur (UE) :
- la soumission à la couche application d'un signal d'erreur de liaison radio et de
l'indicateur de puissance précoce (RSSI-t1) déterminé dans le premier temps et l'indicateur
de puissance ultérieur (RSSI-t2) déterminé dans le second temps.
15. Système selon la revendication 13, dans lequel la couche d'application (10) est adaptée
à la fourniture des étapes suivantes en cas d'identification d'erreur de liaison radio
:
- l'indicateur de puissance précoce (RSSI-t1) déterminé dans le premier temps est
comparé à l'indicateur de puissance ultérieur (RSSI-t2) déterminé dans le second temps,
et déterminé après l'identification d'erreur de liaison radio.
- une affection de brouillage est indiquée dans le cas où la comparaison montre que
l'intensité du signal radio large bande reçu est inchangée ou a augmenté entre le
premier temps et le second temps.