EP0256701A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Crosspoint circuitry for data packet space division switches
Assignee: AT&T Inc
•
Filing: 1987-07-29
•
Granted: —
•
Expires: 2007-07-29
Abstract
Abstract An electronics space-division packet switch is disclosed in which each switch crosspoint includes digital logic capable of resolving simultaneous contentions for the source output buss medium. In particular, a bit-by-bit comparison (51) of priority codes disconnects all switches (54) but the one with the highest priority from the output buss (12). This extremely simple crosspoint switch structure makes possible extremely large space-division packet switches in very compact physical form, using large scale integration techniques.
Inventors
- 👤 Alexander Gibson Fraser
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-29 16:09
CPC Classifications
H; H04; H04L; H04L49/00; H04L49/10; H04L49/101; H04L49/20; H04L49/201; H04L49/205; H04L49/30; H04L49/3018; H04L49/40
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
95 words
A digital crosspoint switch for data packets including address headers, said switch comprising: an array of input busses and output busses, priority code generating means and a crosspoint circuit at each crosspoint between each said input buss and each said output busses, CHARACTERIZED IN THAT each of said crosspoint circuits including output address detecting means, and means responsive to only one output address, and controlled by a priority code, for connecting each one of said input busses to only the addressed one of said output busses for the duration of one of said data packets.
Claim 2
Dependent Claim
95 words
A digital crosspoint switch for data packets including address headers, said switch comprising: an array of input busses and output busses, priority code generating means and a crosspoint circuit at each crosspoint between each said input buss and each said output busses, CHARACTERIZED IN THAT each of said crosspoint circuits including output address detecting means, and means responsive to only one output address, and controlled by a priority code, for connecting each one of said input busses to only the addressed one of said output busses for the duration of one of said data packets.
Claim 3
Dependent Claim
27 words
The digital crosspoint switch according to claim 1 CHARACTERIZED IN THAT said priority code generating means is responsive to a destination code in each said data packet.
Claim 4
Dependent Claim
27 words
The digital crosspoint switch according to claim 1 CHARACTERIZED IN THAT said priority code generating means is responsive to a source code in each said data packet.
Claim 5
Dependent Claim
94 words
A space division packet switch comprising: a first plurality of input data packet busses, a second plurality of output data packet busses, crosspoint circuit means connected between each of said input busses and each of said output busses, CHARACTERIZED BY means in each of said crosspoint circuit means, responsive only to data in a data packet, for resolving conflicts between a plurality of data packets requiring the same output buss at the same time, to connect only a single input buss to a single output buss for the duration of a single data packet.
Claim 6
Dependent Claim
94 words
A space division packet switch comprising: a first plurality of input data packet busses, a second plurality of output data packet busses, crosspoint circuit means connected between each of said input busses and each of said output busses, CHARACTERIZED BY means in each of said crosspoint circuit means, responsive only to data in a data packet, for resolving conflicts between a plurality of data packets requiring the same output buss at the same time, to connect only a single input buss to a single output buss for the duration of a single data packet.
Claim 7
Dependent Claim
23 words
The packet switch according to claim 4 CHARACTERIZED IN THAT said packet switch further comprises buffer storage means for storing data packet signals.
Claim 8
Dependent Claim
28 words
The packet switch according to claim 4 CHARACTERIZED IN THAT said crosspoint further comprises contention solution circuitry responsive to priority codes included in each of said data packets.
Claim 9
Dependent Claim
65 words
The packet switch according to claim 6 CHARACTERIZED IN THAT said contention resolution circuitry includes means for comparing each binary digit of a plurality of simultaneously available priority codes, one digit at a time, and disconnecting all of said input busses with a data packet including a priority code lesser in value than the priority code of any other data packet which is simultaneously available.
Claim 10
Dependent Claim
62 words
The packet switch according to claim 7 CHARACTERIZED IN THAT said comparing means includes means for transmitting each digit of all said priority codes on the same output buss, comparing the combined digits on the ouput buss with each digit of the priority code of each contending packet, and disconnecting all contending packets having a bit value different from said combined digit.
Claim 11
Independent Claim
98 words
The method of switching digital data packets between a plurality of input busses and a plurality of output busses, said method CHARACTERIZED BY detecting the address of a unique one of said ouput busses in the header of a data packet on any one of said input busses, detecting a priority code in the header of each data packet on input busses simultaneously contending for the same output buss, connecting only that one of a plurality of simultaneously contending packets on different input busses having the highest valued priority code, to the output buss addressed by said address.
Claim 12
Independent Claim
98 words
The method of switching digital data packets between a plurality of input busses and a plurality of output busses, said method CHARACTERIZED BY detecting the address of a unique one of said ouput busses in the header of a data packet on any one of said input busses, detecting a priority code in the header of each data packet on input busses simultaneously contending for the same output buss, connecting only that one of a plurality of simultaneously contending packets on different input busses having the highest valued priority code, to the output buss addressed by said address.
Claim 13
Dependent Claim
29 words
The method of switching digital data packets according to claim 9 further CHARACTERIZED BY generating said priority codes in response to information in the headers of said data packets.
Claim 14
Dependent Claim
97 words
A space division packet switch comprising: a first plurality of input lines for supplying data packets, a second plurality of output lines for delivering said data packets, CHARACTERIZED BY means connecting the crosspoint of each of said input lines with each of said output lines for connecting one, and only one, input line to each output line for the duration of one of said data packets, and means associated with each of said input lines for buffering data packets which are not transmitted to an output line and for delivering buffered data packets at a later time.
Claim 15
Dependent Claim
97 words
A space division packet switch comprising: a first plurality of input lines for supplying data packets, a second plurality of output lines for delivering said data packets, CHARACTERIZED BY means connecting the crosspoint of each of said input lines with each of said output lines for connecting one, and only one, input line to each output line for the duration of one of said data packets, and means associated with each of said input lines for buffering data packets which are not transmitted to an output line and for delivering buffered data packets at a later time.
Claim 16
Dependent Claim
48 words
The space division packet switch according to claim 11 further CHARACTERIZED BY means responsive to a priority code associated with each of said data packets for resolving simultaneous requests for connection to the same output line in favor of the data packet associated with the highest priority code.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.