Browse Prior Art Database

Multiple Transmission Speeds for Asynchronous Networks

IP.com Disclosure Number: IPCOM000115921D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2005-Mar-30
Document File: 2 page(s) / 93K

Publishing Venue

IBM

Related People

Olnowich, HT: AUTHOR

Abstract

Disclosed is an asynchronous network having the capability of simultaneously transmitting data at variable rates within a predefined frequency range. The solution applies to parallel interconnect systems, wherein a plurality of nodes are interconnected by a multi-stage network comprised of switches cascaded into stages. Each node can transmit messages or data through the network to any other node. The disclosed network has the unique capability of permitting each node to transfer data at its own native clock speed, where n nodes could transfer at n different rates into the same network at the same time, all n nodes could transfer at the same rate, or any mixture of allowable rates could be used.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 51% of the total text.

Multiple Transmission Speeds for Asynchronous Networks

      Disclosed is an asynchronous network having the capability of
simultaneously transmitting data at variable rates within a
predefined frequency range.  The solution applies to parallel
interconnect systems, wherein a plurality of nodes are interconnected
by a multi-stage network comprised of switches cascaded into stages.
Each node can transmit messages or data through the network to any
other node.  The disclosed network has the unique capability of
permitting each node to transfer data at its own native clock speed,
where n nodes could transfer at n different rates into the same
network at the same time, all n nodes could transfer at the same
rate, or any mixture of allowable rates could be used.  The only
limitation of the network is that the rate at which each node
transmits must be within the range that the switch technology can
support.  For example, a network can be built having these qualities
from an IBM* product called the Allnode Switch.  The first Allnode
switch is capable of handling frequencies up to 40 MHZ.  This means
that any node of the system can transmit at any rate between 0 and 40
MHZ, and the network will function properly.  Rates above 40 MHZ
would be out of range of the technology and would not be supported.
Future and better technologies would allow an expanded range.

      The key to providing an interconnection network that supports
multiple transmission speeds lies in the switching component of the
network.  It must have the characteristics of being unclocked,
unbuffered, and be able to conform automatically to the speed at
which an individual node transmits.  A basic self-routing switch,
such as the Allnode Switch shown in the Figure having 8 input ports
and 8 output ports, performs three different functions: (1) it
establishes a connection from any of the 8 input ports to any of the
8 output ports, (2) it passes data over the formed connection, and
(3) it breaks the connection.  For instance, a typical first switch
function would be to connect Node 1 to Node 8, a typical second
switch function would be to pass data from Node 1 to 8 over the
established connection, a typical third switch function would be to
break the connection of Node 1 to Node 8....