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Claims  |
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What is claimed is:
1. A transmitter identification system for identifying a transmitter which
produces a transmitter signal in which information is encoded by
manipulating a carrier, the transmitter signal including external signal
traits resulting from said manipulation that are characteristic of said
transmitter, comprising:
receiving means located remote from said transmitter for receiving said
transmitter signal;
characterizing means connected to said receiving means for generating a
plurality of characterizing signals for said transmitter by measuring
features of said external signal traits resulting from said manipulation
that are characteristic of said transmitter; and
converting means connected to said characterizing means for converting said
plurality of characterizing signals into a current security pattern
wherein said current security pattern is used to identify said
transmitter,
wherein said converting means produces said current security pattern by
generating feature codes for said plurality of characterizing signals by
establishing, separately for each feature, a scale dividing a range of
possible values of a characterizing signal for said feature into a
predetermined number of divisions, each division being associated with a
unique code, said scale divisions including an upper division and a lower
division, and
wherein a feature code for said feature is produced by assigning said
characterizing signal to one of said predetermined number of divisions, as
follows:
(a) if said characterizing signal is above a first predetermined value,
assigning said characterizing signal a feature code corresponding to said
upper division;
(b) if said characterizing signal is below a second predetermined value,
assigning said characterizing signal a feature code corresponding to said
lower division; and
(c) if said characterizing signal is not above said first predetermined
value and not below said second predetermined value, assigning said
characterizing signal a feature code, intermediate said features codes
which fall between said upper and lower divisions, reflecting the
relationship said characterizing signal bears to said first and second
predetermined values.
2. The transmitter identification system of claim 1 further comprising:
historic security pattern storing means for storing historic security
patterns, each including a plurality of feature codes, for a plurality of
transmitters;
first comparing means connected to said converting means and said historic
security pattern storing means for comparing each of said feature codes of
said current security pattern of said transmitter to corresponding feature
codes of at least one of said historic security patterns stored in said
historic security pattern storing means,
wherein said first comparing means generates feature confidence levels,
separately for each feature, related to a difference between each of said
feature codes of said current security pattern and said corresponding
feature codes of said at least one of said historic security patterns, and
wherein said first comparing means generates an overall transmitter
confidence level from said feature confidence levels.
3. The transmitter identification system of claim 2 wherein said first
comparing means generates one of a mismatch signal, a possible mismatch
signal, and a match signal for said transmitter by establishing a scale
dividing a range of possible values of said overall transmitter confidence
level as follows;
(a) if said overall transmitter confidence level is above a third
predetermined value, generating said mismatch signal;
(b) if said overall transmitter confidence level is below a fourth
predetermined value, generating said match signal; and
(c) if said overall transmitter confidence level is not above said third
predetermined value and not below said fourth predetermined value,
generating said possible mismatch signal, wherein said third predetermined
value is greater than said fourth predetermined value.
4. Apparatus for identifying a wireless subscriber unit and for granting or
denying said wireless subscriber unit access to a subscriber service, said
wireless subscriber unit generating a wireless subscriber signal in which
data is encoded by manipulating a carrier, said wireless subscriber signal
containing external signal traits resulting from said manipulation that
are characteristic of said wireless subscriber unit, and said data
including an identification code, comprising:
receiving and transmitting means located remote from said wireless
subscriber unit for receiving said wireless subscriber signal;
characterizing means connected to said receiving and transmitting means for
generating a plurality of characterizing signals for said wireless
subscriber unit by measuring features of said external signal traits
resulting from said manipulation that are characteristic of said wireless
subscriber unit; and
converting means connected to said characterizing means for converting said
plurality of characterizing signals into a current security pattern
wherein said current security pattern and said identification code are
used to identify said wireless subscriber unit,
wherein said converting means produces said current security pattern by
generating feature codes for said plurality of characterizing signals by
establishing, separately for each feature, a scale dividing a range of
possible values of a characterizing signal for said feature into a
predetermined number of divisions, each division being associated with a
unique code, said scale divisions including an upper division and a lower
division, and
wherein a feature code for said feature is produced by assigning said
characterizing signal to one of said predetermined number of divisions, as
follows:
(a) if said characterizing signal is above a first predetermined value,
assigning said characterizing signal a feature code corresponding to said
upper division;
(b) if said characterizing signal is below a second predetermined value,
assigning said characterizing signal a feature code corresponding to said
lower division; and
(c) if said characterizing signal is not above said first predetermined
value and not below said second predetermined value, assigning said
characterizing signal a feature code, intermediate said feature codes
which fall between said upper and lower divisions, reflecting the
relationship said characterizing signal bears to said first and second
predetermined values.
5. The apparatus of claim 4 further comprising:
historic security pattern storing means for storing historic security
patterns, each including a plurality of feature codes, for a plurality of
wireless subscriber units;
first comparing means connected to said converting means and said historic
security pattern storing means for comparing each of said feature codes of
said current security pattern of said wireless subscriber unit to
corresponding feature codes of at least one of said wireless subscriber
units stored in said historic security pattern storing means,
wherein said first comparing means generates feature confidence levels,
separately for each feature, related to a difference between each of said
feature codes of said current security pattern and said corresponding
feature codes of said at least one of said historic security patterns, and
wherein said first comparing means generates an overall wireless subscriber
unit confidence level from said feature confidence levels.
6. The apparatus of claim 5 further including:
access means connected to said first comparing means for granting or
denying access to said wireless subscriber unit to said subscriber service
based upon said overall wireless subscriber unit confidence level.
7. The apparatus of claim 6 wherein said first comparing means generates
one of a mismatch signal, a possible mismatch signal, and a match signal
for said wireless subscriber unit by establishing a scale dividing a range
of possible values of said overall wireless subscriber unit confidence
level as follows:
(a) if said overall wireless subscriber unit confidence level is above a
third predetermined value, generating said mismatch signal;
(b) if said overall wireless subscriber unit confidence level is below a
fourth predetermined value, generating said match signal; and
(c) if said overall wireless subscriber unit confidence level is not above
said third predetermined value and not below said fourth predetermined
value, generating said possible mismatch signal wherein said third
predetermined value is greater than said fourth predetermined value.
8. The apparatus of claim 7 further comprising:
fraudulent user history storing means for storing fraudulent user security
patterns, each including a plurality of feature codes, for a plurality of
fraudulent wireless subscriber units; and
second comparing means connected to said first comparing means for
comparing said feature codes of said current security pattern of said
wireless subscriber unit to corresponding feature codes of at least one of
said fraudulent user security patterns when said first comparing means
generates the possible mismatch signal.
9. The apparatus of claim 8 wherein said second comparing means generates
fraud feature confidence levels related to a difference between each of
said feature codes of said current security pattern and said corresponding
feature codes of said at least one fraudulent user security pattern, and
produces an overall fraudulent confidence level from said fraudulent
feature confidence levels, wherein said second comparing means generates
one of a fraud match signal or a fraud mismatch signal as follows:
(a) if said overall fraud confidence level is above a fifth predetermined
value, generating said fraud match signal; and
(b) if said overall fraud confidence level is below said fifth
predetermined value, generating said fraud mismatch signal.
10. The apparatus of claim 9 wherein said access means grants access to
said wireless subscriber unit if said first comparing means generates the
match signal, or if said first comparing means generates the possible
mismatch signal and said second comparing means generates the fraud
mismatch signal.
11. The apparatus of claim 10 wherein said access means denies access to
said wireless subscriber unit if said first comparing means generates the
mismatch signal, or if the first comparing means generates the possible
mismatch signal and said second comparing means generates the fraud match
signal.
12. The apparatus of claim 11 wherein said fraudulent user history storing
means is updated with said current security pattern of said wireless
subscriber unit if said second comparing means generates the fraud match
signal.
13. The apparatus of claim 10 wherein said said historic security pattern
stored in said historic security pattern storing means corresponding to
said identification code is updated with said current security pattern of
said wireless subscriber unit if said second comparing means generates the
fraud mismatch signal.
14. The apparatus of claim 4 wherein said converting means compares said
plurality of characterizing signals to a plurality of standard signals and
generates a plurality of multibit signals representing deviation of each
of said characterizing signals from each of said standard signals.
15. The apparatus of claim 14 wherein said converting means combines said
plurality of multibit signals into said current security pattern.
16. The apparatus of claim 14 wherein said converting means combines said
plurality of multibit signals and said identification code into said
current security pattern.
17. The apparatus of claim 4 wherein said characterizing means generates at
least one of said characterizing signals by timing a feature in said
wireless subscriber signal.
18. The apparatus of claim 17 wherein said converting means compares said
at least one of said characterizing signals representing said timing of
said feature to a standard timing signal and generates a first multibit
signal representing deviation of said characterizing signal from said
standard timing signal.
19. The apparatus of claim 4 wherein said characterizing means generates at
least one of said characterizing signals by performing a time comb on a
portion of said wireless subscriber signal.
20. The apparatus of claim 4 wherein said characterizing means generates at
least one of said characterizing signals by generating a frequency
histogram on a portion of said wireless subscriber signal to determine RF
shift of said wireless subscriber signal.
21. The apparatus of claim 4 wherein said characterizing means generates at
least one of said characterizing signals by fitting a line by a
least-means-squared method to a mark portion of said wireless subscriber
signal.
22. The apparatus of claim 4 wherein said characterizing means generates at
least one of said characterizing signals by fitting a line by a
least-means-squared method to a space portion of said wireless subscriber
signal.
23. Apparatus for identifying a wireless subscriber unit and for granting
or denying said wireless subscriber unit access to a subscriber service,
said wireless subscriber unit generating a wireless subscriber signal in
which data is encoded by manipulating a carrier, the wireless subscriber
signal containing external signal traits resulting from said manipulation
that are characteristic of said wireless subscriber unit, and said data
including an identification code, comprising:
receiving and transmitting means located remote from said wireless
subscriber unit for receiving said wireless subscriber signal;
characterizing means connected to said receiving and transmitting means for
generating a plurality of characterizing signals for said wireless
subscriber unit by measuring features of said external signal traits
resulting from said manipulation that are characteristic of said wireless
subscriber unit;
converting means connected to said characterizing means for converting said
plurality of characterizing signals into a current security pattern,
wherein said current security pattern and said identification code are
used to identify said wireless subscriber unit,
wherein said converting means produces said current security pattern by
generating feature codes for said plurality of characterizing signals by
establishing, separately for each feature, a scale dividing a range of
possible values of a characterizing signal for said feature into a
predetermined number of divisions, each division being associated with a
unique code, said scale divisions including an upper division and a lower
division, and
wherein a feature code for said feature is produced by assigning said
characterizing signal to one of said predetermined number of divisions, as
follows:
(a) if said characterizing signal is above a first predetermined value,
assigning said characterizing signal a feature code corresponding to said
upper division;
(b) if said characterizing signal is below a second predetermined value,
assigning said characterizing signal a feature code corresponding to said
lower division; and
(c) if said characterizing signal is not above said first predetermined
value and not below said second predetermined value, assigning said
characterizing signal a feature code, intermediate said feature codes
which fall between said upper and lower divisions, reflecting the
relationship said characterizing signal bears to said first and second
predetermined values;
historic security pattern storing means for storing historic security
patterns, each including a plurality of feature codes, for a plurality of
wireless subscriber units;
first comparing means connected to said converting means and said historic
security pattern storing means for comparing each of said feature codes of
said current security pattern of said wireless subscriber unit to
corresponding feature codes of at least one of said wireless subscriber
units stored in said historic security pattern storing means corresponding
to said identification code of said wireless subscriber unit,
wherein said first comparing means generates feature confidence levels,
separately for each feature, related to a difference between each of said
feature codes of said current security pattern and said corresponding
feature codes of said at least one of said historic security patterns, and
wherein said first comparing means generates an overall wireless subscriber
unit confidence level from said feature confidence levels;
access means connected to said first comparing means for granting or
denying access to said wireless subscriber unit to said subscriber service
based upon said overall wireless subscriber unit confidence level.
24. A method for identifying a wireless subscriber unit and for granting or
denying said wireless subscriber unit access to a subscriber service, said
wireless subscriber unit generating a wireless subscriber signal in which
data is encoded by manipulating a carrier, the wireless subscriber signal
containing external signal traits resulting from said manipulation that
are characteristic of said wireless subscriber unit, and said data
including an identification code, comprising the steps of:
providing receiving and transmitting means located remote from said
wireless subscriber unit for receiving said wireless subscriber signal;
characterizing said wireless subscriber unit by generating a plurality of
characterizing signals for said wireless subscriber unit by measuring a
plurality of features of said external signal traits resulting from said
manipulation that are characteristic of said wireless subscriber unit;
converting said plurality of characterizing signals to a security pattern
by generating feature codes for said plurality of characterizing signals
by establishing, separately for each feature, a scale dividing a range of
possible values of a characterizing signal for said feature into a
predetermined number of divisions, each division being associated with a
unique code, said scale divisions including an upper division and a lower
division, and
wherein a feature code for said feature is produced by assigning said
characterizing signal to one of said predetermined number of divisions, as
follows:
(a) if said characterizing signal is above a first predetermined value,
assigning said characterizing signal a feature code corresponding to said
upper division;
(b) if said characterizing signal is below a second predetermined value,
assigning said characterizing signal a feature code corresponding to said
lower division; and
(c) if said characterizing signal is not above said first predetermined
value and not below said second predetermined value, assigning said
characterizing signal a feature code, intermediate said feature codes
which fall between said upper and lower divisions, reflecting the
relationship said characterizing signal bears to said first and second
predetermined values;
storing said security pattern and said identification code in an ordered
relationship;
subsequently utilizing said security pattern to grant or deny access to
said subscriber service to a requesting wireless subscriber unit with same
identification code.
25. The method of claim 21 further comprising the steps of:
generating a current security pattern, including a plurality of feature
codes, for said requesting wireless subscriber unit;
comparing said feature codes of said requesting wireless subscriber unit
with corresponding feature codes of said security pattern stored in said
ordered relationship with said identification code;
generating feature confidence levels, separately for each feature, related
to a difference between each of said feature codes of said requesting
wireless subscriber unit and said corresponding feature codes of said
security pattern stored in said ordered relationship with said
identification code;
generating an overall wireless subscriber unit confidence level from said
feature confidence levels.
26. The method of claim 25 further comprising the steps of:
granting or denying access to said wireless subscriber unit to said
subscriber service based upon said overall wireless subscriber unit
confidence level.
27. The method of claim 24 further comprising the step of:
monitoring at least one usage parameter indicative of fraudulent use.
28. The method of claim 27 wherein said usage parameter includes at least
one of a number of times a wireless subscriber unit requests access to
said subscriber service in a first period, and a length of time said
wireless unit uses said subscriber service in second period.
29. A transmitter identification system for identifying a transmitter which
produces a transmitter signal in which information is encoded by
manipulating a carrier, the transmitter signal including external signal
traits resulting from transmitter timing idiosyncrasies that are
characteristic of said transmitter, comprising:
receiving means located remote from said transmitter for receiving said
transmitter signal;
characterizing means connected to said receiving means for generating a
plurality of characterizing signals for said transmitter by measuring
features of said external signal traits resulting from said transmitter
timing idiosyncrasies that are characteristic of said transmitter; and
converting means connected to said characterizing means for converting said
plurality of characterizing signals into a current security pattern
wherein said current security pattern is used to identify said
transmitter,
wherein said converting means produces said current security pattern by
generating feature codes for said plurality of characterizing signals by
establishing, separately for each feature, a scale dividing a range of
possible values of a characterizing signal for said feature into a
predetermined number of divisions, each division being associated with a
unique code, said scale divisions including an upper division and a lower
division, and
wherein a feature code for said feature is produced by assigning said
characterizing signal to one of said predetermined number of divisions, as
follows:
(a) if said characterizing signal is above a first predetermined value,
assigning said characterizing signal a feature code corresponding to said
upper division;
(b) if said characterizing signal is below a second predetermined value,
assigning said characterizing signal a feature code corresponding to said
lower division; and
(c) if said characterizing signal is not above said first predetermined
value and not below said second predetermined value, assigning said
characterizing signal a feature code, intermediate said feature codes
which fall between said upper and lower divisions, reflecting the
relationship said characterizing signal bears to said first and second
predetermined values.
30. The transmitter identification system of claim 29 further comprising:
historic security pattern storing means for storing historic security
patterns, each including a plurality of feature codes, for a plurality of
transmitters;
first comparing means connected to said converting means and said historic
security pattern storing means for comparing each of said feature codes of
said current security pattern of said transmitter to corresponding feature
codes of at least one of said historic security patterns stored in said
historic security pattern storing means,
wherein said first comparing means generates feature confidence levels,
separately for each feature, related to a difference between each of said
feature codes of said current security pattern and said corresponding
feature codes of said at least one of said historic security patterns, and
wherein said first comparing means generates an overall transmitter
confidence level from said feature confidence levels.
31. The transmitter identification system of claim 30 wherein said first
comparing means generates one of a mismatch signal, a possible mismatch
signal, and a match signal for said transmitter by establishing a scale
dividing a range of possible values of said overall transmitter confidence
level as follows:
(a) if said overall transmitter confidence level is above a third
predetermined value, generating said mismatch signal;
(b) if said overall transmitter confidence level is below a fourth
predetermined value, generating said match signal; and
(c) if said overall transmitter confidence level is not above said third
predetermined value and not below said fourth predetermined value,
generating said possible mismatch signal wherein said third predetermined
value is greater than said fourth predetermined value.
32. Apparatus for identifying a wireless subscriber unit and for granting
or denying said wireless subscriber unit access to a subscriber service,
said wireless subscriber unit generating a wireless subscriber signal in
which data is encoded by manipulating a carrier, said wireless subscriber
signal containing external signal traits resulting from wireless
subscribing unit timing idiosyncrasies that are characteristic of said
wireless subscriber unit, and said data including an identification code,
comprising:
receiving and transmitting means located remote from said wireless
subscriber unit for receiving said wireless subscriber signal;
characterizing means connected to said receiving and transmitting means for
generating a plurality of characterizing signals for said wireless
subscriber unit by measuring features of said external signal traits
resulting from said wireless subscriber unit timing idiosyncrasies that
are characteristic of said wireless subscriber unit; and
converting means connected to said characterizing means for converting said
plurality of characterizing signals into a current security pattern
wherein said current security pattern and said identification code are
used to identify said wireless subscriber unit,
wherein said converting means produces said current security pattern by
generating feature codes for said plurality of characterizing signals by
establishing, separately for each feature, a scale dividing a range of
possible values of a characterizing signal for said feature into a
predetermined number of divisions, each division being associated with a
unique code, said scale divisions including an upper division and a lower
division, and
wherein said feature code for said feature is produced by assigning said
characterizing signal to one of said predetermined number of divisions, as
follows:
(a) if a characterizing signal is above a first predetermined value,
assigning said characterizing signal a feature code corresponding to said
upper division;
(b) if said characterizing signal is below a second predetermined value,
assigning said characterizing signal a feature code corresponding to said
lower division; and
(c) if said characterizing signal is not above said first predetermined
value and not below said second predetermined value, assigning said
characterizing signal a feature code, intermediate said feature codes
which fall between said upper and lower divisions, reflecting the
relationship said characterizing signal bears to said first and second
predetermined values.
33. The apparatus of claim 32 further comprising:
historic security pattern storing means for storing historic security
patterns, each including a plurality of feature codes, for a plurality of
wireless subscriber units;
first comparing means connected to said converting means and said historic
security pattern storing means for comparing each of said feature codes of
said current security pattern of said wireless subscriber unit to
corresponding feature codes of at least one of said wireless subscriber
units stored in said historic security pattern storing means,
wherein said first comparing means generates feature confidence levels,
separately for each feature, related to a difference between each of said
feature codes of said current security pattern and said corresponding
feature codes of said at least one of said historic security patterns, and
wherein said first comparing means generates an overall wireless subscriber
unit confidence level from said feature confidence levels.
34. The apparatus of claim 33 further including:
access means connected to said first comparing means for granting or
denying access to said wireless subscriber unit to said subscriber service
based upon said overall wireless subscriber unit confidence level.
35. The apparatus of claim 34 wherein said first comparing means generates
one of a mismatch signal, a possible mismatch signal, and a match signal
for said wireless subscriber unit by establishing a scale dividing a range
of possible values of said overall wireless subscriber unit confidence
level as follows:
(a) if said overall wireless subscriber unit confidence level is above a
third predetermined value, generating said mismatch signal;
(b) if said overall wireless subscriber unit confidence level is below a
fourth predetermined value, generating said match signal; and
(c) if said overall wireless subscriber unit confidence level is not above
said third predetermined value and not below said fourth predetermined
value, generating said possible mismatch signal, wherein said third
predetermined value is greater than said fourth predetermined value.
36. The apparatus of claim 35 further comprising:
fraudulent user history storing means for storing fraudulent user security
patterns, each including a plurality of feature codes, for a plurality of
fraudulent wireless subscriber units; and
second comparing means connected to said first comparing means for
comparing said feature codes of said current security pattern of said
wireless subscriber unit to corresponding feature codes of at least one of
said fraudulent user security patterns when said first comparing means
generates the possible mismatch signal.
37. The apparatus of claim 36 wherein said second comparing means generates
fraud feature confidence levels related to a difference between each of
said feature codes of said current security pattern and said corresponding
feature codes of said at least one fraudulent user security pattern, and
produces a fraud confidence level from said fraudulent feature confidence
levels, wherein said second comparing means generates one of a fraud match
signal or a fraud mismatch signal as follows:
(a) if said fraud confidence level is above a fifth predetermined value,
generating said fraud match signal; and
(b) if said fraud confidence level is below said fifth predetermined value,
generating said fraud mismatch signal.
38. The apparatus of claim 37 wherein said access means grants access to
said wireless subscriber unit if said first comparing means generates | | |
