Shanti S Gupta, 96120 Juneberry Ct, Hockessin, DE 19707

4319352, Mar 9, 1982

Sep 27, 1979

6/079602

Shanti S. Gupta - Gaithersburg MD
Brady Warner - Santa Maria CA
Joseph H. Deal - Clarksburg MD

Communications Satellite Corporation - Washington DC

H04J 316

370104

A plurality of terrestrial interface modules (TIMs) are multiplexed and demultiplexed with common equipment through the use of mapping RAMs contained in each TIM. The common equipment provides identical addresses to each of the mapping RAMs in the TIMs. The mapping RAMs in each TIM determine whether incoming or outgoing data is to be written into or read from the associated TIM, and generate an address for the data so written into or read from the TIM. A mapping RAM is further provided in the common equipment to allow for burst-to-burst selection of data.

4354164, Oct 12, 1982

Sep 27, 1979

6/079671

Shanti S. Gupta - Gaithersburg MD

Communications Satellite Corporation - Washington DC

H03L 708

331 1A

A phase lock loop for a frequency synthesizer operating by counting different frequencies to a common fixed number to generate different time bases. An error signal is generated by counting bits of a first frequency over a given count relative to bits received at a second reference frequency. If an error occurs, a programmed frequency change takes place, otherwise the synthesizer is maintained at the programmed center frequency. Error detection resumes with a new counting period determined by the programmed change.

4286219, Aug 25, 1981

Sep 27, 1979

6/079603

Shanti S. Gupta - Gaithersburg MD

Communications Satellite Corporation - Washington DC

H03L 700
H03B 1900

328 14

A programmable frequency source is used to synthesize a wide range of frequencies in small increments. A master oscillator and a single programmable divider are used. Each selected frequency possesses a phase jitter, predictable and a function of the master oscillator-to-output frequency relationship. The output of the frequency source is a square wave whose transitions are edge synchronous with the master oscillator.

5161191, Nov 3, 1992

Nov 27, 1990

7/618617

Shanti S. Gupta - Gaithersburg MD
Darryl C. Morris - Herndon VA

H04K 104

380 37

An encryption system is provided for interfacing a time division multiplexing (TDM) telecommunications arrangement with an encryption device for the scrambling of data received by the telecommunications arrangement. The telecommunications arrangement produces a TDM data stream formatted into TDM frames including a predetermined number of TDM framing bits and corresponding framing bit locations. At a local side of the system, a first TDM data stream is received and sampled, and the TDM framing bit information is detected and stored therefrom. The data stream is then sent to an encryptor for encryption, and thereafter the TDM framing bit information is reinserted into the corresponding bit locations of the encrypted data stream. As a result, the TDM framing bit information is passed around the encryptor. This encrypted data stream and framing bit information is transmitted to a remote station across a TDM (e. g.