Narrow band simulcast system having low speed data distribution
AssigneeEricsson Inc.
InventorThomas A. Brown
Life of this patent
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AssigneeEricsson Inc.
InventorThomas A. Brown
Estimating the term…
A "narrow band" public service trunking (PST) simulcast radio frequency transmission system having high-speed and low-speed digital data access capabilities in addition to analog voice operates in the 900 MHz frequency-range, as distinguished from a conventional "wide band" PST system that operates in the 800 MHz frequency range. In a narrow band PST simulcast system having digital access capabilities, the handling of low speed digital data must be accomplished differently than high speed data since it becomes unique to each channel. This would ordinarily require providing an additional data path for each channel, or a wider band width audio path neither of which is feasible or cost effective. Arrangements are therefore provided for the routing of low-speed data to each transmit site via the high-speed digital data channel path for each site and for holding the high-speed data resynchronization circuitry at each site at its previous latency during the transmission of low-speed data, which would otherwise cause erroneous triggering of the resynchronization circuitry.
In a radio frequency communications system having plural spatially separated RF transmitters all transmitting substantially the same signal at substantially the same radio frequency, said system distributing a common clocking signal to each of said plural transmitters so as to facilitate a substantially simultaneous signal transmission by said plural transmitters and also distributing message data and control signal data to each of said transmitters over a high-speed data channel from a central control point, said central control point including:
In a narrow band type public service trunked simulcast radio frequency transmission system having plural transmitter sites, at least one high-speed data channel from a central control point to each transmitter site for carrying message data and control signal data to said transmitter sites, and having high-speed data signal synchronization circuitry associated with said high-speed data channel at each site, a method for providing both high-speed and low-speed digital data over a single high speed data channel to each site, comprising the steps of:
Dependencies are inferred from the claim text.