US 5,331,316 AGranted

Communication system including allocating free signalling channels to individual substations having data to transmit

AssigneeAlcatel

InventorsDenis J. G. Mestdagh, Robertus J. Van Engelshoven, Bart J. G. Pauwels

Life of this patent

Estimating the term…

Loading patent…

Abstract

A communication system includes a main station (MS) and a plurality of substations (SX/SZ) which include each a transceiver and are all connected in parallel to first (UL) and second (DL) unidirectional links on which recurrent first and second cells of fixed length are transmitted in opposite direction. Each of these cells contains a plurality of signalling channels smaller than the number of substations. When a substation has to transmit data it starts an allocation procedure wherein the substation cooperates with the main station and by which a channel is allocated to it. Afterwards prior to transmitting the data the substation transmits a request signal in the allocated channel and starts transmission after having received from the main station a grant signal in the homologous signalling channel of a second cell. De-allocation of a channel occurs as soon as the latter is no longer needed.

Claims23

Dependent claims

A communication system comprising

a main station,
a plurality of substations connected in parallel to a first path on which recurrent first cells are conveyed from the substations to the main station and to a second path on which recurrent second cells are conveyed from the main station to the substations, each of said first and second cells including a plurality of signalling channels smaller than the number of substations and a data channel each of said substations further comprising
a substation transmitter to write information into said first cells including the writing of signalling channel allocation request signals in corresponding signalling channels, and
a substation receiver to read information from said second cells, including an indication of which of said signalling channels of said first cells are currently free,
a main station receiver to read information from said first cells, including said signalling channel allocation request signals,
a main station transmitter to write information into said second cells, including said indication of which of said signalling channels of said first cells are currently free, and for broadcasting said second cells to all said substations,
allocation means in said main station and in each of said substations, for resolving conflicting signalling channel allocating requests and for allocating a free one of said plurality of signalling channels of said first cells to a substation having data to transmit,
request signal transmission means in each substation having, one of said signalling channels of said first cells allocated to said each substation, for transmitting to said main station a data transmission request signal in said one allocated signalling channel of one of said first cells, and
grant signal means in said main station for transmitting a data transmission grant signal to the requesting substation in a signalling channel of one of said second cells in response to the receipt of said data transmission request signal.

6 more elements

A communication system comprising:

a main station;
a plurality of substations intercoupled by a first path on which recurrent first cells are conveyed from the substations to the main station and by a second path on which recurrent second cells are conveyed from the main station to the substations, each of said first and second cells including a plurality of signalling channels smaller than the number of substations and a data channel, each of said substations further comprising
a substation transmitter to write information into said first cells each including a plurality of signalling channels;
and
a substation receiver to read information from said second cells;
a main station receiver to read information from said first cells;
a main station transmitter to write information into said second cells including an indication of which of said signalling channels of said first cells are currently free, and for broadcasting said second cells to all said substations;
allocation means in said main station and in each of said substations, for allocating a free one of said plurality of signalling channels of said first cells to a particular substation having new data to be transmitted towards said main station, said allocation means further comprising
means in said particular substation for provisionally selecting a free signalling channel in a substation allocation register storing general allocation status information of all the signalling channels, for deriving an own allocation status information from the general allocation status information by marking the selected free channel as busy and for storing the own allocation status information in a byte register;
means in said particular substation for writing a signalling channel allocation request signal in the selected signalling channel of a first cell transmitted towards said main station;
means in said main station for transmitting an allocation grant signal in the selected signalling channel of a second cell being transmitted to all said substations;
means in said particular substation for writing an own address from an own address register of said particular substation into the data channel of an echo first cell being transmitted towards said main station;
means in said main station for recognizing a received echo cell and to transmit a return echo second cell corresponding to the received echo cell to all said substations;
and
means in each of said substations for comparing the address stored in said own address register with the address of said return echo second cell, the provisionally selected signalling channel being definitively allocated to said each substation if and only if the comparison is successful;
request signal transmission means in each substation having one of said signalling channels of said first cells allocated to said each substation, for transmitting to said main station a data transmission request signal in said one signalling channel of one of said first cells;
and
data transmission grant signal means in said main station for transmitting a data transmission grant signal to the requesting substation in a signalling channel of one of said second cells in response to the receipt of said data transmission request signal.

15 more elements

Dependencies are inferred from the claim text.