Neural-model, computational architecture employing broadcast hierarchy and hypergrid, point-to-point communication

A hybrid neural-model computational architecture which employs both broadcast hierarchical bus communication for high fan-out communication situations and point-to-point grid communication for low fan-out communication situations.

BACKGROUND AND SUMMARY OF THE INVENTION 
This invention pertains to a neural-model computational architecture 
structure, and more particularly, to such a structure which combines the 
significant advantages of a system employing broadcast hierarchy, as well 
as those of a system employing point-to-point, grid-bus communication. 
In my U.S. Pat. No. 4,796,199, issued Jan. 3, for "NEURAL-MODEL, 
INFORMATION-HANDLING ARCHITECTURE AND METHOD", I have described a unique 
neural-model computational method and architecture structure which 
features broadcast hierarchy, and locality-of-communication dominance. 
This multi-communication-level system offers a unique organization of 
physical nodes and connection nodes which tends to maximize the 
capabilities and advantages of a neural-model, connectionist, 
computational network, through featuring a dominance of 
locality-of-communication performances in the way that connections 
(communications) take place. 
The entire disclosure of that patent application is hereby incorporated 
herein by reference. 
Another kind of computational architecture, which is not necessarily based 
on a neural-model, is one in which a grid structure interconnects the 
physical nodes to permit non-broadcast, point-to-point, go-to-address 
specific communication. Those skilled in this field of art are familiar 
with the well-known workings (hardware and software) associated with such 
systems. 
The present invention proposes a unique marriage of these two kinds of 
systems in a manner which offers, in a unitary system, which is a 
neural-model connectionist system, the special and important advantages of 
both. 
Explaining further, in the new kind of broadcast-hierarchical, neural-model 
system which I describe in my above-referred-to patent application, there 
is one kind of circumstance which is not well handled, strictly speaking, 
by a rigid implementation of broadcast hierarchy. In that system, 
locality-of-communication dominance is achieved by structuring the system 
in such a manner that each connection node has preferably all, or at least 
a very dominant portion, of its intended connections established as local 
connections which use the lowest communication level bus provided in the 
system. Connection nodes which are intended to communicate more frequently 
with more distant connection nodes broadcast, typically with somewhat less 
frequency, over a higher level bus. And, in the particular system 
described in that patent application, yet a third level of hierarchical 
communication is provided over a third, highest-level bus which 
accommodates the longest-distance node-to-node, typically low frequency, 
communication. 
In that system, one requirement is that, in order properly to implement the 
broadcast feature, the bus level over which a particular connection node 
communicates is defined by the highest-level bus which it must employ for 
its longest-distance connection. Thus, somewhat of a problem arises where 
the architecture of a system results with a number of connection nodes 
having a predominance of low-level, short-distance connections, along with 
a few higher-level, longer-distance connections. These nodes, because they 
must broadcast over one of the higher-level buses during the relatively 
few times that they make long-distance connections, nevertheless occupy 
the time and territory of this higher-level bus for each and every one of 
the much more frequent lower-level communications. Thus, a situation 
exists which tends to diminish, somewhat, the efficiency which that system 
is capable of providing. 
According to a preferred embodiment of the present invention, the marriage 
which was mentioned above results in the use of what is referred to herein 
as a hypergrid bus which, in most cases, and in the particular instance 
illustrated herein, is connected to each and every one of the physical 
nodes in a system like that described in my prior-referenced patent 
application. This hypergrid bus is a non-broadcast structure, and 
specifically takes the form of a plurality of point-to-point communication 
buses that extend in a grid fashion between selected, adjacent physical 
nodes. Through appropriate programming of the system, employing techniques 
which are well known to those skilled in the art, under a circumstance 
where a connection node, which may otherwise have a plurality of 
high-frequency, low-level connections to make, "desires" to make one or 
more of its intended longer-distance, non-local connections, the following 
occurs: the physical node associated with this connection node accesses 
the hypergrid bus (rather than any one of the broadcast-level buses), and 
employing go-to-addressing, and appropriate routing information, directs 
communication from this connection node to the specific, other, distant 
connection node with which it needs to communicate, or to any specific 
point in the system. 
The advantages of the marriage should be immediately obvious to those 
skilled in the art. Nodes which have both high-frequency (local) and 
low-frequency (distant) connections (communications) to make, make the 
former on the appropriate broadcast bus, and the latter exclusively via 
the hypergrid bus. These advantages, and others which are offered by the 
combination proposed by the present invention, will become more clearly 
appreciated as the description which now follows is read in conjunction 
with the accompanying drawings.

DETAILED DESCRIPTION OF THE INVENTION 
Turning attention now to the two drawing figures, indicated generally at 10 
is a computational system which is constructed in accordance with the 
present invention. System 10 is also referred to herein as a neural-model, 
broadcast-hierarchical, locality-of-communication-dominant, 
information-handling architecture structure. It will become apparent to 
the reader, in the description which now follows, that system 10, as 
disclosed herein, is displayed as a relatively simple system in order to 
promote an easy understanding of the architecture and the operation of the 
system. In actual practice, a real-life system will, as will be obvious to 
those skilled in the art, be far more extensive, in order to offer the 
practical capability of neural-model processing. Despite the simplicity, 
however, which has been chosen to illustrate system 10, all of the 
structural and operational principles of the invention are fully disclosed 
and implemented therein. Those skilled in the art will recognize 
immediately how these principles can be applied in the making and using of 
a large, real-life system. In reading the description which now continues, 
the reader should recall that I have incorporated by reference the 
entirety of the disclosure contained in the prior-filed patent which I 
have mentioned earlier in this writing. Accordingly, a full discussion of 
the various communication levels which are present in system 10, whose 
descriptions and whose operations, are detailed in the prior patent, are 
omitted from the text of this specification. 
Progressing from a bird's-eye to a worm's-eye view of system 10, it 
includes two collections 12, 14 of physical nodes and connection nodes 
which are organized, within these collections, as will now be described. 
It should be explained that what are shown as the contents of collection 
12 also exist, with the same layout and pattern, in collection 14, and 
that a description generally of the contents of collection 12 fully 
describes the like contents of collection 14. 
Within collection 12 there are four subdivisions, also referred to as 
groups or as neighborhoods, 16, 18, 20, 22, within each of which are four 
further subdivisions, referred to as families, such as the families shown 
at 24, 26, 28, 30 in group 16. 
Within each family, such as within family 24, are a physical node, or a 
communication center, such as node 32, and four connection nodes, or 
communication units, such as those shown at 34, 36, 38, 40. As has been 
suggested just above, vis-a-vis avoiding unnecessary complexity, family 24 
is illustrated with only four connection nodes associated with node 32. In 
practice, node 32, as well as all of the other physical nodes in the 
system, would typically be associated with about one-thousand connection 
nodes. 
As can be seen, the associated physical and connection nodes which appear 
in FIG. 1 are illustrated only with respect to families 24, 26. It should 
be understood, of course, that all of the other families present in system 
10 have the same internal structures. And, while such is true for the 
system now being described, it should be understood further that different 
physical nodes in a system may be associated with different numbers of 
connection nodes in a particular architectural implementation. 
The simplification of FIG. 2 referred to earlier is one in which only the 
physical nodes in collections 12, 14 are illustrated (and only 
fragmentarily in collection 14). Thus, physical node 32 appears near the 
upper left corner as a small rectangle within collection 12, and it will 
be understood that all of the other small rectangles shown in this 
collection, and the three shown in fragmented collection 14, represent the 
other physical nodes in system 10. 
Describing generally the hierarchical nature of system 10, in the 
particular system shown there are three information-handling, or 
communication, levels. The number of such levels is dictated by the fact 
that the physical and connection nodes are organized herein in three 
different kinds of assemblies--collections, groups and families, as 
mentioned earlier. A hierarchical system exists, of course, whenever there 
are two or more communication levels. A three-level system has been chosen 
here for illustration purposes. 
Considering the communication broadcast aspects of system 10, for each 
level of communication, there is a specific bus structure which allows 
communication from a given connection node to be broadcast throughout the 
relevant portion of that level, which broadcast is "listened-to" by all of 
the physical nodes which are connected to that bus structure. Each 
physical node in the system is connected to all three levels of bus 
structure in order to be aware (for reception/communication purposes) of 
all incoming communications, and to be prepared to transmit an outgoing 
communication when required. 
At 42, 44, 46, 48 in FIG. 1 there are shown four brackets which symbolize a 
first, low-level bus structure (communication level) for each of groups 
16, 18, 20, 22, respectively. All of the physical nodes in group 16 are 
connected to bus 42; all of the physical nodes in group 18 are connected 
to bus 44; and so on. 
This organization is illustrated in somewhat more detail, and on a larger 
scale than has been used for FIG. 1 herein, in FIG. 2 of the 
above-referred-to, prior-filed patent application. 
At 50, 52, 54, 56 in FIG. 1, are four brackets which symbolize, for the 
groups in collection 14, the same first, low-level bus structure which has 
just been described for the groups in collection 12. 
At 58, 60 in FIG. 1, are two brackets which symbolize a second, 
higher-level bus structure (communication level), with bus 58 being 
associated with collection 12, and bus 60 being associated with collection 
14. Bus 58 is connected to all sixteen of the physical nodes in collection 
12, and bus 60 is connected to all sixteen of the physical nodes in 
collection 14. FIG. 3 in the referenced prior-filed patent application 
illustrates this situation in greater detail. 
Symbolized by a bracket 62 in FIG. 1 is a bus, or bus structure 
(communication level), which links collections 12, 14. This, in system 10, 
is the highest-communication-level broadcast bus structure. A somewhat 
more detailed showing of bus 62 appears in FIG. 4 in the prior-filed 
patent application. Bus 62 is connected to all of the physical nodes 
within system 10. 
Indicated at 64 in FIG. 1 is another family in system 10, which family 
happens to reside in collection 14 in a "location" which corresponds to 
that of family 24 in collection 12. Residing within family 64 is a 
physical node 66. The reason for introducing a single family within group 
14, and that family's associated physical node, is to aid in an 
understanding of what is shown in FIG. 2. 
On the buses so far described in system 10, communication throughout the 
system takes place by way of broadcast, using "come-from" addressing to 
identify the communicating connection node. This pattern of communication 
is fully described and illustrated in my prior-filed patent, incorporated 
by reference herein. 
This broadcast-type communication is characterized by what is known as 
locality-of-communication-dominance, whereby the nodes which communicate 
with one another most frequently are coupled preferentially over the 
lowest-level bus, those that communicate less frequently on the 
intermediate-level bus, and those with the lowest frequency of 
communication on the highest-level broadcast bus. 
As was mentioned earlier herein, in the preamble portion of this 
specification, it may well be the case that a given connection node which 
has a high frequency of communication, and which can be localized with its 
communicating partners for operation on the lowest level bus, may also 
have one or more longer-distance communications which, in the absence of 
the present invention, would require that it always operate, and occupy 
unnecessary time, on one of the higher-level buses. 
To take care of this situation, proposed according to the present invention 
is yet another bus or bus structure, referred to herein also as a 
hypergrid bus, which is shown generally at 68 in FIG. 2. Bus 68 is 
connected to all of the physical nodes in system 10, and several of these 
nodes are shown in FIG. 2, with previously mentioned physical nodes 32, 66 
being pointed out specifically. In system 10, bus 68 is made up of a 
plurality of bus runs, such as the two shown at 68a, 68b, which extend in 
a point-to-point fashion between selected, adjacent physical nodes. 
The system proposed by this invention, which is a hybrid by nature, 
uniquely combines the positive efficiencies of broadcast hierarchical and 
point-to-point networks. The former is most efficient with so-called high 
fan-out communication situations, and least efficient with low fan-out 
communication. The latter exhibits just the reverse characteristic. Thus, 
the proposed hybrid marries the best of the two. With, as is always the 
case in a given physical system, a fixed communication capacity 
(physical), the hybrid allocation of this fixed capacity to both broadcast 
hierarchical and point-to-point communication offered by the present 
invention maximizes the use of the "physical real estate" available. 
In system 10, when a long-distance communication is required from one 
connection node to another, where the communicating connection node is 
also one that preferably will use the lowest-level bus structure, its 
communications are handled on a point-to-point basis over bus structure 
68, employing go-to addressing. In the field of computer architecture, the 
employment of a grid bus to handle point-to-point, go-to-address 
communication is well known to those skilled in the art, as are the 
programming and structural techniques required to implement such 
communication. Put another way, those skilled in the art will recognize 
immediately how to implement, in the otherwise broadcast-hierarchical 
nature of system 10, a hypergrid bus, such as bus 68, to handle the 
potentially troublesome long-distance communications. 
By way of a simple illustration, let us assume that within family 24, 
previously mentioned connection node 34 (see FIG. 1) is intended to 
communicate predominantly with the connection nodes in the other families 
in group 16. Let us also assume that node 34 is intended, on a very 
infrequent basis, to communicate with a connection node in family 64. In 
the absence of hypergrid bus 68, it would be necessary that every 
communication from node 34 take place in a broadcast fashion over the 
highest-level bus in the system, bus 62. The inefficiency of such a 
situation is obvious. 
However, with system 10 structured according to the invention (including 
bus 68), all of the communications from node 34 which are made to nodes 
within group 16 take place in a broadcast fashion over low-level bus 42. A 
communication which is made to a node in family 64 takes place in a 
non-broadcast fashion, and more specifically in a point-to-point, 
go-to-address fashion, via routing over bus 68. The information which is 
communicated by node 34's physical node 32 is conventionally structured to 
achieve appropriate routing to physical node 66, and thence to the 
designee connection node which is associated with node 66. Such a 
point-to-point broadcasting and routing technique is one which is well 
known to those skilled in the art. 
From the description which has just been given, it should be apparent how 
the marriage of the broadcast-hierarchical system which is disclosed in my 
above-referred-to, prior-filed patent application, with a point-to-point, 
go-to-address-only, hypergrid bus, such as bus 68, according to the 
invention, offers significant performance advantages. 
While a preferred embodiment of the invention has been described herein, I 
recognize that various changes and modifications may be made to 
accommodate different computational requirements. For example, it is not 
absolutely necessary that a hypergrid bus connect with all of the physical 
nodes in an otherwise hierarchical, broadcast-type architecture. Such a 
bus need only be present to handle that portion of the architecture 
wherein the short-distance/long-distance bus competition possibility 
presents a problem. 
With regard to the term "broadcast hierarchy", etc., various 
implementations other than the specific one shown herein may be used. For 
example, a hierarchical network can exist with overlapping broadcast 
regions. 
The term "grid" used herein is intended not only to cover a two-dimensional 
arrangement such as the one illustrated and described, but also other 
multi-dimensional organizations. Also, the term "grid" is intended to 
encompass any kind of implementable point-to-point communication 
connection system. 
Certainly, other kinds of specific modifications may be made to suit other 
considerations, and all of these variations and modifications may take 
place without departing from the spirit of the invention.