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US5710971A Expired / Lapsed US ⏱️ 0.0 years remaining

Radio communication network and method for unobstrusive call interception via data duplication

Assignee: CDC Propriete Intellectuelle
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Filing: 1995-12-18
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Granted: 1998-01-20
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Expires: 2015-12-18
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Abstract

Abstract A digital cellular telecommunication network (30) uses transcoders (50) which vocode voice using a maximal lossy compression algorithm which conserves spectrum usage. A call path for an intercepted call is looped from an outer space satellite (32) network into a terrestrial gateway (34). Compressed call data for each of two half-calls in this call path are duplicated at any of the network nodes and inserted into the opposing half-call. In addition, the compressed call data are decompressed in a gateway transcoder (50), combined in a conference bridge (90), and routed to a monitoring center (60). A subscriber unit (36), a second device (48), and the monitoring center (60) all receive call data which has experienced only one compression/decompression cycle.

Inventors

  • 👤 Peter Joseph Armbruster
  • 👤 Johanna Alexandra Wild
  • 👤 Dean Paul Vanden Heuvel
  • 👤 Scott David Blanchard

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-06 16:05
CPC Classifications
H; H04; H04B; H04B7/00; H04B7/14; H04B7/15; H04B7/185; H04B7/1853; H04B7/18558; H04B7/1856

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 136 words
A method of unobtrusively intercepting a call routed through a radio link of a telecommunication network, the method comprising the steps of: a) establishing the call and a departing portion of a call path between a subscriber unit and a second device; b) receiving compressed call data from the subscriber unit at a network node, the compressed call data being received through the call path that includes an RF communication link; c) duplicating the compressed call data at the network node to obtain first compressed call data and second compressed call data; d) routing the first compressed call data from the network node toward the second device; e) routing the second compressed call data toward a monitoring center; and f) refraining from performing more than one compressing operation within the departing portion of the call path.
Claim 2
Independent Claim 136 words
A method of unobtrusively intercepting a call routed through a radio link of a telecommunication network, the method comprising the steps of: a) establishing the call and a departing portion of a call path between a subscriber unit and a second device; b) receiving compressed call data from the subscriber unit at a network node, the compressed call data being received through the call path that includes an RF communication link; c) duplicating the compressed call data at the network node to obtain first compressed call data and second compressed call data; d) routing the first compressed call data from the network node toward the second device; e) routing the second compressed call data toward a monitoring center; and f) refraining from performing more than one compressing operation within the departing portion of the call path.
Claim 3
Dependent Claim 31 words
A method as recited in claim 1, further comprising the steps of: g) decompressing the first compressed call data; and h) decompressing the second compressed call data independently from step g.
Claim 4
Dependent Claim 31 words
A method as recited in claim 1, wherein step (b) includes the step of receiving the compressed call data from the subscriber unit at an in-view satellite located in outer space.
Claim 5
Dependent Claim 39 words
A method as recited in claim 3, wherein the in-view satellite is one of a plurality of satellites located in outer space; and each of the satellites has a radio coverage area extending over a fraction of earth's surface.
Claim 6
Dependent Claim 33 words
A method as recited in claim 3, further comprising the steps of: locating the network node proximate earth's surface; and transmitting the compressed call data from the in-view satellite to the network node.
Claim 7
Dependent Claim 28 words
A method as recited in claim 5, wherein: the in-view satellite has a coverage area; and the network node and the subscriber unit reside within the coverage area.
Claim 8
Dependent Claim 71 words
A method as recited in claim 1, further comprising the steps of: routing return compressed call data to the network node; duplicating the return compressed call data at the network node to obtain first return compressed call data and second return compressed call data; routing the first return compressed call data from the network node toward the subscriber unit; and routing the second return compressed call data toward the monitoring center.
Claim 9
Independent Claim 145 words
A method of unobtrusively intercepting a call routed through a radio link of a telecommunication network, the method a comprising the steps of: a) establishing the call and a departing portion of a call path between a subscriber unit and a second device; b) obtaining call data at the subscriber unit; c) compressing the call data at the subscriber unit to obtain compressed call data; d) transmitting the compressed call data to a network node using an RF communication link; e) duplicating the compressed call data at the network node to obtain first compressed call data and second compressed call data; f) routing the first compressed call data from the network node toward the second device; g) routing the second compressed call data toward a monitoring center; and h) refraining from performing more than one compressing operation within the departing portion of the call path.
Claim 10
Independent Claim 145 words
A method of unobtrusively intercepting a call routed through a radio link of a telecommunication network, the method a comprising the steps of: a) establishing the call and a departing portion of a call path between a subscriber unit and a second device; b) obtaining call data at the subscriber unit; c) compressing the call data at the subscriber unit to obtain compressed call data; d) transmitting the compressed call data to a network node using an RF communication link; e) duplicating the compressed call data at the network node to obtain first compressed call data and second compressed call data; f) routing the first compressed call data from the network node toward the second device; g) routing the second compressed call data toward a monitoring center; and h) refraining from performing more than one compressing operation within the departing portion of the call path.
Claim 11
Dependent Claim 19 words
A method as recited in claim 8, wherein the compressing step is configured to achieve approximately maximal lossy compression.
Claim 12
Dependent Claim 33 words
A method as recited in claim 8, wherein step (c) includes the step of forming a stream of data occurring at a rate of less than 6400 bits/s from the compressed call data.
Claim 13
Dependent Claim 91 words
A method as recited in claim 8, further comprising the steps of: obtaining return call data at the second device; compressing the return call data to obtain return compressed call data; routing the return compressed call data to the network node; duplicating the return compressed call data at the network node to obtain first return compressed call data and second return compressed call data; routing the first return compressed call data from the network node toward the subscriber unit; and routing the second return compressed call data toward the monitoring center.
Claim 14
Dependent Claim 29 words
A method as recited in claim 8, further comprising the steps of: decompressing the first compressed call data; and decompressing the second compressed call data independently from step h).
Claim 15
Dependent Claim 149 words
A network allowing unobtrusive interception of a call established between a subscriber unit and a second device, the network comprising: a plurality of network nodes in communication with one another, wherein one of the network nodes is in radio communication with the subscriber unit, one of the network nodes is in communication with the second device, and one of the network nodes is a duplicating node, wherein the duplicating node comprises: means for duplicating compressed call data received from the subscriber unit into first compressed call data and second compressed call data; first routing means, coupled to the duplicating means, for routing the first compressed call data toward the second device and for refraining from performing more than one compressing operation within a departing portion of a call path; and second routing means, coupled to the duplicating means, for routing the second compressed call data toward a monitoring center.
Claim 16
Dependent Claim 149 words
A network allowing unobtrusive interception of a call established between a subscriber unit and a second device, the network comprising: a plurality of network nodes in communication with one another, wherein one of the network nodes is in radio communication with the subscriber unit, one of the network nodes is in communication with the second device, and one of the network nodes is a duplicating node, wherein the duplicating node comprises: means for duplicating compressed call data received from the subscriber unit into first compressed call data and second compressed call data; first routing means, coupled to the duplicating means, for routing the first compressed call data toward the second device and for refraining from performing more than one compressing operation within a departing portion of a call path; and second routing means, coupled to the duplicating means, for routing the second compressed call data toward a monitoring center.
Claim 17
Dependent Claim 75 words
A radio telecommunication network as recited in claim 13, wherein: the first routing means routes the first compressed call data along a first call path; the second routing means routes the second compressed call data along a second call path; the network further comprises means for decompressing the first compressed call data within the first call path; and the network further comprises means for decompressing the second compressed call data within the second call path.
Claim 18
Dependent Claim 37 words
A radio telecommunication network as recited in claim 13, wherein: the one node in radio communication with the subscriber unit is located in a satellite residing in outer space; and the duplicating node resides proximate earth's surface.
Claim 19
Dependent Claim 41 words
A radio telecommunication network as recited in claim 13, wherein: the one node in radio communication with the subscriber unit is located in a satellite residing in outer space; and the duplicating node resides in any network node in outer space.
Claim 20
Dependent Claim 147 words
A network allowing unobtrusive interception of a call established between a subscriber unit and a second device, the network comprising: a plurality of network nodes in communication with one another, wherein one of the network nodes is in radio communication with the subscriber unit, one of the network nodes is in communication with the second device, and one of the network nodes is a duplicating node, wherein the duplicating node comprises: duplicator capable of duplicating compressed call data received from the subscriber unit into first compressed call data and second compressed call data; first router, coupled to the duplicator, capable of routing the first compressed call data toward the second device and for refraining from performing more than one compressing operation within a departing portion of a call path; and second router, coupled to the duplicator, for routing the second compressed call data toward a monitoring center.
Claim 21
Dependent Claim 147 words
A network allowing unobtrusive interception of a call established between a subscriber unit and a second device, the network comprising: a plurality of network nodes in communication with one another, wherein one of the network nodes is in radio communication with the subscriber unit, one of the network nodes is in communication with the second device, and one of the network nodes is a duplicating node, wherein the duplicating node comprises: duplicator capable of duplicating compressed call data received from the subscriber unit into first compressed call data and second compressed call data; first router, coupled to the duplicator, capable of routing the first compressed call data toward the second device and for refraining from performing more than one compressing operation within a departing portion of a call path; and second router, coupled to the duplicator, for routing the second compressed call data toward a monitoring center.

References Cited (Backward Citations)

US5255305A Cited
US5394458A Cited
US5305308A Cited
US5509004A Cited
US5566181A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2001-01-19 2001-07-21 2002-01-20 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2005-01-19 2005-07-21 2006-01-20 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2009-01-19 2009-07-21 2010-01-20 $7700.00 Window Closed / Lapsed

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