# US 5,710,978 A · Logging recorder system for trunking radio > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,710,978 A - Document ID: US5710978A - Status: Granted - Kind: A - Application number: 08/450,029 - Filed: 1995-05-25 - Granted: 1998-01-20 - Earliest claimed: 1993-06-29 - Assignees: Swift Computers, Inc. - Inventors: Carl J. Swift - Web page: https://patentgrep.com/patent/US5710978A ## CPC - H04W 84/08: Trunked mobile radio systems - H04L 63/30: {for supporting lawful interception, monitoring or retaining of communications or communication related information (circuit switched telephony call monitoring H04M3/2281)} - H04M 3/42221: {Conversation recording systems (at the subscriber's set H04M1/656)} - H04W: WIRELESS COMMUNICATION NETWORKS (broadcast communication H04H; communication systems using wireless links for non-selective communication, e.g. wireless extensions H04M1/72) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - H04M: TELEPHONIC COMMUNICATION (circuits for controlling other apparatus via a telephone cable and not involving telephone switching apparatus G08) ## Abstract A logging recorder system for trunking radio includes a device which monitors a plurality of channels of the trunking radio system and outputs analog signals representative thereof. A digitizer is then provided for digitizing the analog signals, and a controller breaks the digitized signals into segments and stores the segments on a storage device. The controller also generates an index of locations of the segments on the storage device. The controller may then be used to selectively play back a desired conversation by automatically combining segments from the storage device based on the index. ## Claims ### Claim 1 A logging recorder for a trunking radio system having a plurality of channels that carry streams of segments from unrelated conversations according to channel assignment information generated by a trunking controller, comprising: a plurality of fixed frequency radios each of which monitors a selected one of said plurality of channels; a controller which monitors said fixed frequency radios and generates identification information corresponding to said segments based upon said channel assignment information; means for combining each of said segments with said corresponding identification information; and means for storing said segments and said identification information on a storage device. ### Claim 2 (depends on 1) A logging recorder as claimed in claim 1, further comprising means for playing back a desired conversation by automatically retrieving and combining appropriate ones of said segments based upon said identification information. ### Claim 3 (depends on 1) A logging recorder as claimed in claim 1, further comprising means for digitizing selected outputs of said fixed frequency radios. ### Claim 4 (depends on 3) A logging recorder as claimed in claim 3, further comprising means for compressing the digitized selected outputs. ### Claim 5 (depends on 1) A logging recorder as claimed in claim 1, wherein said identification information is appended to a corresponding one of said segments prior to storage. ### Claim 6 (depends on 1) A logging recorder as claimed in claim 1, wherein said identification information comprises a channel identifier. ### Claim 7 (depends on 1) A logging recorder as claimed in claim 1, wherein said identification information comprises a user identifier. ### Claim 8 (depends on 1) A logging recorder as claimed in claim 1, wherein said identification information comprises a talk group identifier. ### Claim 9 (depends on 1) A logging recorder as claimed in claim 1, wherein said identification information comprises a time identifier. ### Claim 10 (depends on 1) A logging recorder as claimed in claim 1, wherein said identification information comprises a channel identifier, a talk group identifier, and a time identifier. ### Claim 11 (depends on 5) A logging recorder as claimed in claim 5, wherein said identification information comprises a channel identifier. ### Claim 12 (depends on 5) A logging recorder as claimed in claim 5, wherein said identification information comprises a user identifier. ### Claim 13 (depends on 5) A logging recorder as claimed in claim 5, wherein said identification information comprises a talk group identifier. ### Claim 14 (depends on 5) A logging recorder as claimed in claim 5, wherein said identification information comprises a time identifier. ### Claim 15 (depends on 5) A logging recorder as claimed in claim 5, wherein said identification information comprises a channel identifier, a talk group identifier, and a time identifier. ### Claim 16 (depends on 1) A logging recorder as claimed in claim 1, wherein said storage device comprises a hard drive. ### Claim 17 (depends on 1) A logging recorder as claimed in claim 1, wherein said storage device comprises magnetic tape. ### Claim 18 (depends on 1) A logging recorder as claimed in claim 1, wherein said storage device comprises an electronic memory device. ### Claim 19 (depends on 1) The logging recorder as claimed in claim 1, wherein the storage device comprises an optical storage device. ### Claim 20 A digital logging recorder for a trunking radio system having a plurality of channels that carry streams of segments from unrelated conversations according to channel assignment information generated by a trunking controller, comprising: means for monitoring the plurality of channels and outputting analog signals representative thereof; means for digitizing selected ones of said analog signals; control means for monitoring the digitized signals and generating identification information corresponding to said segments based upon said channel assignment information; means for combining each of said segments with said corresponding identification information; and means for storing said segments and said identification information on a storage device. ### Claim 21 (depends on 18) A logging recorder as claimed in claim 18, further comprising means for playing back a desired conversation by automatically retrieving and combining appropriate ones of said segments based upon said identification information. ### Claim 22 A method of logging a trunking radio system having a plurality of channels that carry streams of segments from unrelated conversations according to channel assignment information generated by a trunking controller, comprising the steps of: monitoring said plurality of channels; generating identification information corresponding to said segments based upon said channel assignment information; combining each of said segments with said corresponding identification information; and storing said segments and said identification information on a storage device. ### Claim 23 (depends on 22) The method of claim 22, further comprising the step of converting the segments to digital signals. ### Claim 24 (depends on 22) The method of claim 22, further comprising the step of appending said identification information to a corresponding one of said segments. ### Claim 25 A digital logging system, comprising: a plurality of fixed frequency radios each of which monitors a selected channel of a trunking radio system; a controller which monitors said fixed frequency radio and records selected segments of outputs thereof on a mass storage device in indexed fashion according to information received from a trunking controller; and means for playing back a desired conversation by automatically combining said segments based on said index. ### Claim 26 A digital logging recorder for a trunking radio system having a plurality of communication channels that transmit communications between subscriber stations according to control information generated by a trunking controller, comprising: a plurality of receivers, each of which receives a transmission from one of the communication channels and outputs an analog audio signal; signal processing circuitry which converts the analog audio signal into segments of digital audio data each of which contains a portion of the transmission; a controller which receives the control information and generates indexing information corresponding to each of the segments of digital audio data and which combines the indexing information with the corresponding segment of digital audio data, the indexing information identifying the portion of the transmission contained in the corresponding segment of digital audio data; and a storage medium which stores the indexed segments of digital audio data. ### Claim 27 (depends on 26) The digital logging recorder of claim 26, wherein the signal processing circuitry comprises: conversion circuitry which converts the analog audio signal into a plurality of digital samples; and a digital signal processor which compresses the digital samples into the segments of digital audio data. ### Claim 28 (depends on 27) The digital logging recorder of claim 27, wherein the digital signal processor is configured to collect a predetermined number of said digital samples and to compress said predetermined number of digital samples into a digital audio data segment of predetermined size. ### Claim 29 (depends on 26) The digital logging recorder of claim 26, wherein the storage medium includes sets of digital audio data segments, each of which is capable of accepting a predetermined maximum number of the segments of digital audio data. ### Claim 30 (depends on 26) The digital logging recorder of claim 26, further comprising a mass storage medium which receives one of the sets of digital audio data segments when the set of digital audio data segments reaches the predetermined maximum number of segments. ### Claim 31 (depends on 26) The digital logging recorder of claim 26, wherein the indexing information provides at least one of the following pieces of information about each transmission: identification of a subscriber station originating the transmission, group identification of subscriber stations involved in the transmission, identification of the communication channel carrying the transmission, and a time identifier. ### Claim 32 (depends on 26) The digital logging recorder of claim 26, wherein the signal processing circuitry is configured to convert the digital audio data segments into an analog audio playback signal. ### Claim 33 (depends on 26) The digital logging recorder of claim 26, wherein the controller is configured to receive a playback criterion from an operator and to compare the playback criterion against the indexing information corresponding to each of the segments of digital audio data; and wherein if the indexing information corresponding to one of the segments of digital audio data satisfies the playback criterion, the signal processing circuitry is configured to convert that segment of digital audio data into an analog playback signal and to provide the analog playback signal to a sound reproducing device. ### Claim 34 A method of logging a transmission from a trunking radio system having a plurality of communication channels controlled by control information generated by a trunking controller, comprising: recovering from the control information data allocating one of the communication channels for the transmission; receiving an analog audio signal transmitted on the allocated communication channel; converting the analog audio signal into segments of digital audio data each of which contains a portion of the transmission; generating indexing information corresponding to each of the segments of digital audio data, the indexing information identifying the portion of the transmission contained in the corresponding segment of digital audio data; combining the indexing information with the corresponding segment of digital audio data; and storing each of the indexed segments of digital audio data to a storage medium. ### Claim 35 (depends on 34) The method of claim 34, further comprising the step of reconstructing the analog audio signal from the stored segments of digital audio data. ### Claim 36 (depends on 35) The method of claim 35, wherein the step of reconstructing the analog audio signal comprises: generating a data segment selection criterion; retrieving selected ones of the stored segments of digital audio data from the storage medium according to the data segment selection criterion; converting the retrieved segment of digital audio data into an analog audio playback signal; and playing the analog audio playback signal through a sound reproducing device. ### Claim 37 A method of playing back a trunking radio transmission stored as segments of digital audio data on a storage medium, the method comprising: generating a data selection criterion which provides information about the trunking radio system transmission; comparing the data selection criterion against data segment indexing information to identify each of the segments of digital audio data corresponding to the trunking radio transmission; retrieving each of the identified segments of digital audio data from the storage medium; converting each of the retrieved segments of digital audio data into an analog sound signal; and playing the analog sound signal through a sound reproducing device. ### Claim 38 (depends on 37) The method of claim 37, wherein the step of converting each of the retrieved segments of digital audio data into an analog sound signal comprises: expanding each of the retrieved segments into a plurality of digital audio samples; and converting the digital audio samples into an analog signal. ### Claim 39 A method of simultaneously recording and playing back a trunking radio system transmission comprising: receiving an analog audio signal transmitted on one of a plurality of trunking radio channels; converting the analog audio signal into a digital signal; dividing the digital audio signal into a plurality of data segments; storing each of the data segments to a storage medium; comparing each of the data segments to a predetermined playback criterion; and if one of the data segments satisfies the predetermined playback criterion, converting the data segment into an analog playback signal and playing the analog playback signal through a sound reproducing device. ### Claim 40 (depends on 39) The method of claim 39, further comprising the steps of: using a signal processor in a signal coding mode to create the plurality of data segments; and switching the signal processor into a signal decoding mode to create the analog playback signal.