Method of access control in a communication system using orthogonal functions
First Claim
1. In a time division multiplex system having a common duplex transmission channel divided into a plurality of time slots among a plurality of independent subscriber stations, a method for allocating access of said time slots among said stations comprising:
- transmitting from each of said stations desiring access to the transmission channel during one of said time slots a substantially orthogonal pulse function signal identifying said desiring access station;
receiving at a central station connected to said duplex transmission channel said orthogonal pulse function signal;
distinguishing the subscriber station initiating said orthogonal pulse function from other stations by determining the frequency of said orthogonal pulse;
transmitting from said central station over one of said time slots a request flag to said identified subscriber station to more completely identify itself, said request flag comprising the identity of the received orthogonal pulse function; and
receiving at said subscriber station said transmitted request from said central station, and transmitting in a time slot a complete identification of said subcriber station whereby said central station can fully identify said subscriber station and allocate a time slot for said subscriber station.
3 Assignments
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Accused Products
Abstract
In a communication system having a plurality of mutually independent subscriber stations, these stations seize a common duplex transmission channel for establishing a connection in accordance with a multiple-access method. To prevent simultaneous access and the resultant access destruction and also in the case of frequent access destruction of the blocking of the common duplex transmission channel, each transmission station, to initiate a transmission therefrom, seizes the duplex transmission channel by means of a signalling character. The signalling character is transmitted by the subscriber station during a time slot allocated for that purpose. To distinguish between reporting subscriber stations, a pulse function from a system of orthogonal or substantially orthogonal pulse functions is used as an identification character. The subscriber stations occupy the duplex transmission channel in time slots authorized for access, uncoordinated in time, with, for example, a randomly selected orthogonal pulse function.
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Citations
6 Claims
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1. In a time division multiplex system having a common duplex transmission channel divided into a plurality of time slots among a plurality of independent subscriber stations, a method for allocating access of said time slots among said stations comprising:
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transmitting from each of said stations desiring access to the transmission channel during one of said time slots a substantially orthogonal pulse function signal identifying said desiring access station; receiving at a central station connected to said duplex transmission channel said orthogonal pulse function signal; distinguishing the subscriber station initiating said orthogonal pulse function from other stations by determining the frequency of said orthogonal pulse; transmitting from said central station over one of said time slots a request flag to said identified subscriber station to more completely identify itself, said request flag comprising the identity of the received orthogonal pulse function; and receiving at said subscriber station said transmitted request from said central station, and transmitting in a time slot a complete identification of said subcriber station whereby said central station can fully identify said subscriber station and allocate a time slot for said subscriber station. - View Dependent Claims (2, 3, 4, 5, 6)
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Specification