Manual of U.S. Patent Classification
as of June 30, 2000

Class
455
TELECOMMUNICATIONS

Class definitions may be accessed by clicking on the class title, above.
Subclass definitions may be accessed by clicking on the subclass number, below.

Patents classified in a subclass may be accessed by clicking on the " " icon following the subclass number, below.

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For search strategies, please refer to the Classification Index Explanation of Data web page.

Subclass		Title
ClassTitle		===> TELECOMMUNICATIONS
1		INTERFERENCE SIGNAL TRANSMISSION (E.G., JAMMING)
2		AUDIENCE SURVEY OR PROGRAM DISTRIBUTION USE ACCOUNTING
3.1		DISTRIBUTION SYSTEM (E.G., PLURAL CABLES, ETC.)
3.2		. Receiver for satellite broadcast
3.3		. Combined with power distribution network
4.1		. Remote control of distribution
4.2		. . With subscriber selection or switching
5.1		. Two-way
6.1		. Common antenna or cable
6.2		. . With specific cable converter
6.3		. Combined with diverse art device (e.g., audio/sound or entertainment systems)
400		HAVING SINGLE-CHANNEL TELEPHONE CARRIER
401		. Including call signaling (e.g., ringing, off-hook, dialing)
402		. Over power line
403		RADIOTELEPHONE SYSTEM
404		. Emergency or alarm communication
405		. Usage measurement
406		. . Billing
407		. . . At subscriber unit
408		. . . At remote station
409		. . Rental
410		. Security or fraud prevention
411		. . Privacy, lock-out, or authentication
412		. Message storage or retrieval
413		. . Voice mail
414		. Special service
415		. . Caller identification
416		. . Call conferencing
417		. . Call diversion
418		. Programming control
419		. . Remote programming control
420		. . . Control of another apparatus
421		. Out-of-range indication
422		. Zoned or cellular telephone system
423		. . Diagnostic testing, malfunction indication, or electrical condition measurement
424		. . . System equipment
425		. . . Subscriber equipment
426		. . Including other radio communication system (e.g., cordless telephone, paging, trunking, etc.)
427		. . Space satellite
428		. . . Switching or routing
429		. . . Cell projection
430		. . . Ground station control
431		. . Airborne or aircraft
432		. . Roaming
433		. . . Home location registration (HLR) or visitor location registration (VLR) detail
434		. . Control or access channel scanning
435		. . Registration
436		. . Handoff
437		. . . Mobile assisted or initiated
438		. . . Serving site initiated
439		. . . Handoff initiated by another source (e.g., target, user initiated, mobile switching center (MSC), or mobile telephone switching office (MTSO), etc.)
440		. . . Based upon unit location
441		. . . Based upon unit velocity
442		. . . Soft handoff
443		. . . Overlapping cells
444		. . . Between macro and micro cells
445		. . Call routing (e.g., to prevent backhaul, routing efficiency, least cost, or alternate routing)
446		. . Including cell planning or layout
447		. . . Frequency reuse scheme
448		. . . Co-located systems
449		. . . Hierarchical cell structure
450		. . Channel allocation
451		. . . Hybrid allocation
452		. . . Dynamic allocation
453		. . . Load balancing
454		. . . Spectrum sharing for different type of system (e.g., point-to-point microwave, television, etc.)
455		. . Channel seizing
456		. . Location monitoring
457		. . . Location display
458		. . Specific paging technique
459		. . . Meet-me system
460		. . . Auto-dialing
461		. Including personal numbering system (i.e., intelligent network for subscriber tracking or follow-me subscriber feature)
462		. Including private cordless extension system
463		. . Multi-users
464		. . Channel selection or allocation
465		. Including public cordless extension system
466		. Auxiliary data signaling (e.g., short message service (SMS))
7		CARRIER WAVE REPEATER OR RELAY SYSTEM (I.E., RETRANSMISSION OF SAME INFORMATION)
8		. Failure compensation (e.g., spare channel)
9		. Monitoring
10		. . Fading compensation
11.1		. Portable or mobile repeater
12.1		. . Space satellite
13.1		. . . With plural repeater or relay systems
13.2		. . . With synchronizing of satellites or system
13.3		. . . With antenna feed network or multiple antenna switching
13.4		. . . Power control
14		. With transmission line
15		. Two separate way transmission
16		. . Simultaneous using plural repeaters at each location
17		. Plural modulated carriers
18		. With delay or recording
19		. Common antenna
20		. With frequency conversion
21		. . With demodulator
22		. . Plural conversion stages
23		. Frequency or phase modulation
24		. Transmitter/receiver feedback compensation
25		. Directive antenna
26.1		USE OR ACCESS BLOCKING (E.G., LOCKING SWITCH)
31.1		SYSTEM WITH RECEIVER SELECTION
31.2		. Control of selectively responsive paging arrangement over telephone line
31.3		. . Two-way paging system
32.1		. Receiver scans for address signal
35.1		. Tone coded squelch
36.1		. . Plural tones
37.1		. . . Difference frequency
38.1		. Coded sequence
38.2		. . With actuation (e.g., turn on/off or alarm indication, etc.)
38.3		. . . Power control or battery saving
38.4		. . . Visual indication
38.5		. . . Tone sequence
39		TRANSMITTER AND RECEIVER AT SEPARATE STATIONS
40		. Earth or water medium
41		. Near field (e.g., inductive or capacitive coupling)
42		. Frequency or phase modulation
43		. . With modification of frequencies of analog signal passed (e.g., pre-emphasis and de-emphasis)
44		. . With stated modulation index
45		. . Via subcarrier
46		. Suppressed carrier wave system
47		. Single or vestigial sideband system
48		. Inverted sideband
500		. Plural transmitters or receivers (i.e., more than two stations)
501		. . Noise, distortion, or singing reduction
502		. . . Synchronized stations
503		. . . . Simulcast system
504		. . . Fading compensation
505		. . . . Due to weather
506		. . . . Rayleigh or multipath fading
507		. . Central station (e.g., master, etc.)
508		. . . Having console
509		. . . Channel allocation
510		. . . . Plural requests (e.g., retries)
511		. . . . Control channel/voice channel conversion
512		. . . . Based on priority
513		. . . . Ranking (e.g., based on signal strength, etc.)
514		. . . . Having storage detail
515		. . . Control channel monitoring (i.e., paging or access channel signaling) for system access
516		. . . Channel seizing
517		. . . To or from mobile station
518		. . . . Having talk group
519		. . . . . Talk group forming (e.g., dynamic regrouping, talk group assignment)
520		. . . . . On-site or multi-site trunking
521		. . . . Emergency dispatch or response
522		. . . . Transmission power control technique
523		. . . . Using radiating transmission line
524		. . . . Multiple base stations
525		. . . . . Base station selection
526		. . . Plural receivers tuned to common frequency
527		. . Break-in or priority override
528		. . Lockout or busy-idle signaling
59		. Single message via plural carrier wave transmission
60		. . Different phases of same frequency carrier
61		. Single message via plural modulation of single carrier
62		. Optimum frequency selection
63		. Distortion, noise, or other interference prevention, reduction, or compensation
64		. . Plasma source or barrier
65		. . Anti-multipath
66		. With diverse art device
67.1		. With measuring, testing, or monitoring of system or part
67.2		. . Using a chamber (e.g., room testing or audio surveillance, etc.)
67.3		. . Noise, distortion or unwanted signal detection (e.g., quality control, etc.)
67.4		. . Using a test signal
67.5		. . Of a microwave link or system
67.6		. . Phase measuring (e.g., group delay, propagation effects, etc.)
67.7		. . With indication (e.g., visual or voice signalling, etc.)
68		. With control signal
69		. . Transmitter controlled by signal feedback from receiver
70		. . Receiver control signal originates at message transmitter
71		. . . Frequency control
72		. . . For compression and expansion of message signal (i.e., companding)
73		TRANSMITTER AND RECEIVER AT SAME STATION (E.G., TRANSCEIVER)
74		. Convertible (e.g., to diverse art device)
74.1		. . Cordless/corded conversion
75		. With frequency stabilization (e.g., automatic frequency control)
76		. . Synthesizer
77		. With tuning
78		. With transmitter-receiver switching or interaction prevention
79		. . Automatic (e.g., voice operated)
80		. . . With distributed parameter coupling
81		. . . . Waveguide
82		. . . Common antenna
83		. . Single antenna switched between transmitter and receiver
84		. With a common signal processing stage
85		. . Transmitter oscillator used as detector
86		. . Transmitter oscillator used as local oscillator
87		. . . Tunable or variable
88		. Transceiver controlling a separate transceiver or receiver
550		. Radiotelephone equipment detail
551		. . Number assignment module (NAM) detail
552		. . Operable on more than one system
553		. . . Dual mode telephone (i.e., analog and digital)
554		. . Remote private branch exchange (PBX) with wireless link to landline
555		. . Wireless private branch exchange (PBX) (i.e., wireless link to extension unit)
556		. . Integrated with other device (e.g., electronic notebook, personal digital assistant, etc.)
557		. . Interface attached device (e.g., interface with modem, facsimile, computer, etc.)
558		. . . Card control element
559		. . . Smart cable
560		. . Switching unit detail (e.g., mobile telephone switching office (MTSO), base station controller (BSC), etc.)
561		. . Base station detail
562		. . . Having specific antenna arrangement
563		. . Having voice recognition or synthesization
564		. . Auto-dialing or repertory dialing (e.g., using bar code, etc.)
565		. . Restrictive dialing circuitry
566		. . Having display
567		. . Call alerting
568		. . Headgear
569		. . Hands-free or loudspeaking arrangement
570		. . . Noise suppression or echo cancellation
571		. . Power booster
572		. . Power supply
573		. . . Battery charging
574		. . . Power conservation
575		. Portable or mobile
90		. Housing or support
91		TRANSMITTER
92		. Remote control of a transmitter
93		. Convertible to different type (e.g., AM to FM)
94		. Alternator
95		. Mobile or portable
96		. . Transmitter ejected from moving vehicle
97		. . With antenna ejection or external support
98		. . With aircraft, satellite, or projectile
99		. . With vehicle
100		. . Body attached or connected
101		. Diversity
102		. Plural modulation
103		. Plural separate transmitters or channels
104		. . Carrier and sidebands separately transmitted
105		. . Common frequency
106		. Modulation by absorption, shielding, or reflecting
107		. With variation of antenna impedance or dimension for modulation
108		. Amplitude modulation
109		. . Vestigial or single sideband or suppressed carrier
110		. Angle modulation
111		. . Including distributed parameter structure
112		. . With frequency multiplication or division
113		. . With frequency control
114		. With harmonic radiation suppression
115		. Measuring, testing, or monitoring of transmitter
116		. Carrier amplitude control (e.g., voice operated on/off)
117		. With electrical protection of transmitter circuit or operator
118		. Frequency conversion
119		. Carrier frequency stabilization
120		. Including tuning
121		. . In antenna circuit
122		. . . With saturable reactor
123		. . . Automatically controlled
124		. . Distributed parameter device
125		. . Automatic adjustment of tuning
126		. With feedback of modulated output signal
127		. Power or bias voltage supply
128		. With casing or housing
129		. With coupled antenna
130		RECEIVER OR ANALOG MODULATED SIGNAL FREQUENCY CONVERTER
131		. Frequency conversion between signal source (e.g., wave collector) and receiver
132		. Plural receivers
133		. . With output selecting
134		. . . By signal strength
135		. . . By signal quality (e.g., signal to noise ratio)
136		. . . With control (e.g., automatic gain control, automatic frequency control, etc.)
137		. . With output combining
138		. . . With control (e.g., automatic gain control)
139		. . . . Frequency or phase control
140		. . Selectively actuated or controlled
141		. . Including common stage (e.g., local oscillator)
142		. Convertible to different type (e.g., AM to FM)
143		. . With distinct signal path for each type
144		. . With dual purpose amplifying or other stage
145		. Panoramic display
146		. . Plural separate paths or plural oscillators
147		. . Particular local oscillator control
148		. . With oscilloscope sweep signal derivation or control
149		. Plural output (e.g., plural speakers) (not stereo)
150.1		. Signal selection based on frequency (e.g., tuning)
151.1		. . Remote control of channel or station selection
151.2		. . . Wireless link (sonic, RF, or infrared)
151.3		. . . Remote oscillator tuned
151.4		. . . Plural electronic devices controlled
152.1		. . . Of or combined with vehicle receiver
153.1		. . . Mechanical
153.2		. . . . With wired link
154.1		. . With indication of frequency, channel, or selector condition (e.g., tuning aid)
154.2		. . . Scanning display
155.1		. . . By meter
156.1		. . . Audible indicator
157.1		. . . Analog frequency indication (e.g., dial)
157.2		. . . . With light indication or bar type
158.1		. . . Channel index indication
158.2		. . . . With electronic digital indication
158.3		. . . . . Using a counter
158.4		. . . . With multiple display functions
158.5		. . . . Non-numeric display (e.g., call letters)
159.1		. . . Variable light indication
159.2		. . . . Plural lamps
160.1		. . Plural tuning modes (e.g., manual and scanning, etc.)
161.1		. . Frequency scanning
161.2		. . . With processor control
161.3		. . . Using signal strength or quality
162.1		. . . Motor activated
163.1		. . . . Reversible motor (e.g., end-stop control)
164.1		. . . With automatic frequency control
164.2		. . . . Processor controlled (AFC)
165.1		. . . With frequency synthesizer
166.1		. . . With channel skipping selection
166.2		. . . . With priority channel selection
167.1		. . . With dual sweeping
168.1		. . . Multiband
169.1		. . . With particular variable voltage or current tuning
169.2		. . . . With varactor diode
170.1		. . With mechanical or electromechanical selection
171.1		. . . Time actuated
172.1		. . . . Including a motor
173.1		. . . With automatic frequency control of fine tuning
174.1		. . . With muting (e.g., silent tuning)
175.1		. . . With carrier wave preset
176.1		. . . Combined with band selection
177.1		. . . Combined with other control (e.g., bandwidth, volume, gain, etc.)
178.1		. . . With plurality of tunable circuits
179.1		. . Channel or station selection
180.1		. . . Combined with band selection
180.2		. . . . UHF and VHF
180.3		. . . . . With phase locked loop (PLL) tuning
180.4		. . . . . Varactor tuned (e.g., varactor diode)
181.1		. . . Time controlled
182.1		. . . With frequency control
182.2		. . . . Automatic (AFC)
182.3		. . . Fine tuning
183.1		. . . With frequency synthesizer
183.2		. . . . Processor controlled
184.1		. . . With comparing desired and existing tuning conditions
185.1