Frequency division multiplex voice communication apparatus with hierarchy of stations

Claim 2

Communication apparatus comprising, in combination: transmitting means, including output means, for providing at said output means both radio frequency carrier modulated communication signals and audio frequency signals, said transmitting means transmitting communication signals on a plurality of channels and supplying a signaling carrier on at least one of said channels only during periods of transmission of communication signals; first receiving means for detecting only audio frequency signals; second receiving means for detecting only carrier modulated signals; a single communication link means connecting said first and second receiving means to said transmitting means; and third receiving means, connected to said communication link, for detecting carrier modulated signals and for inhibiting operation thereof only during the time of receipt of said signaling carrier.

Claim 3

An article of manufacture for use with a twisted wire pair wherein some communication signals on the pair are accompanied by a signaling carrier; audio signal input means; electrical signal output means; audio signal output means; carrier modulated transmitting means, connected to said audio signal input means and to said electrical signal output means, for supplying carrier output signals to said electrical signal output means, modulated in accordance with audio signals received at said audio input means; audio transmit amplifying means connected to said audio signal input means and said electrical output means, for providing audio frequency signals to said electrical signal output means, modulated carrier signal detection means connected between said electrical signal output means and said audio signal output means for demodulating signals received from said electrical output means and outputting audio frequency signals; and inhibit means connected to said modulated carrier signal detection means for inhibiting operation of said detector means only during time periods when signals are received having a signaling carrier in addition to a transmission carrier but allowing operation of said transmitting means at all times.

Claim 4

An article of manufacture for use with a twisted wire pair wherein some communication signals on the pair are accompanied by a signaling carrier; audio signal input means; electrical signal output means; audio signal output means; carrier modulated transmitting means, connected to said audio signal input means and to said electrical signal output means, for supplying carrier output signals to said electrical signal output means, modulated in accordance with audio signals received at said audio input means; audio transmit amplifying means connected to said audio signal input means and said electrical output means, for providing audio frequency signals to said electrical signal output means, modulated carrier signal detection means connected between said electrical signal output means and said audio signal output means for demodulating signals received from said electrical output means and outputting audio frequency signals; and inhibit means connected to said modulated carrier signal detection means for inhibiting operation of said detector means only during time periods when signals are received having a signaling carrier in addition to a transmission carrier but allowing operation of said transmitting means at all times.

Claim 5

Apparatus for effecting semiprivate communications between one of a plurality of substations on a single line and a master station wherein both audio frequency and higher frequency audio frequency modulated signals appear on the single line comprising, in combination: master station means; a plurality of substation means each having a given communication channel which transmits an auxiliary signal in addition to a communication signal; inhibit means incorporated in each of said substation means for preventing reception of communication signals accompanied by said auxiliary signal, and a single communication link connecting said master station to each of said substation means in series, each substation being receptive to only the master station communication signals on said given channel.

Claim 6

Apparatus for effecting semiprivate communications between one of a plurality of substations on a single line and a master station wherein both audio frequency and higher frequency audio frequency modulated signals appear on the single line comprising, in combination: master station means; a plurality of substation means each having a given communication channel which transmits an auxiliary signal in addition to a communication signal; inhibit means incorporated in each of said substation means for preventing reception of communication signals accompanied by said auxiliary signal, and a single communication link connecting said master station to each of said substation means in series, each substation being receptive to only the master station communication signals on said given channel.

Claim 7

Apparatus as claimed in claim 3 wherein: said substation means contain additional communication channel means which transmit communication signals without the addition of an auxiliary signal, and said single communication link is a twisted wire pair.

Claim 8

Apparatus as claimed in claim 3 wherein: said substation means includes voice operated switch means for transmitting said auxiliary signal simultaneous with verbal communication signals.