Abstract:
A computing architecture and network topology definition module which provide the ability to tailor a hardware network topology to differing needs. Computing resources are interconnected into a network implementation using an optical wavelength division multiplexing (WDM) star/coupler approach. The overall topology for the network is defined by the network topology definition module, which is a removable device that defines the network topology and communication connectivity between the computing resources. Replacement of the network topology definition module with a different network topology definition module changes the network topology and communication connectivity, allowing the computing resources to be tailored to particular needs.

Description:
FIELD 
     This disclosure relates to computing architectures and means for reconfiguring computing architectures. 
     BACKGROUND 
     Many computing architectures have a network topology or configuration that is tied to the underlying network technology. One example is switched Ethernet. Altering the network topology typically requires a change to nonvolatile RAM or to field programmable gate array (FPGA) code, or in some cases a change in optical cable route-path or a cable adjustment on a manual patch panel. 
     SUMMARY 
     A computing architecture and network topology definition module are described which provide the ability to tailor a hardware network topology to differing needs, whereby the topology may be changed quickly, with minimal equipment and without requiring re-cabling and/or adjustments to subsystem computing equipment. The concepts described herein can be used in a large number of applications where tailorable computing topology is desirable. Examples of applications include, but are not limited to, environments where hardware subsystem topology must be reconfigured/redistributed to support multiple mission scenarios, space constrained computing environments where hardware subsystems need to be shared, and hardware manufacturing, testing and diagnostics applications. 
     In one example described herein, computing resources are interconnected into a network implementation using an optical wavelength division multiplexing (WDM) star/coupler approach. The overall topology for the network is defined by the network topology definition module, which is a removable device that defines the network topology and communication connectivity between the computing resources. In the case of the WDM star/coupler approach, the network topology definition module includes a passive star/coupler and wavelength filter components. Replacement of the network topology definition module with a different network topology definition module changes the network topology and communication connectivity, allowing the computing resources to be tailored to particular needs. 
     In one embodiment, the network topology definition module is electrically passive in that no electrical energy is routed to the network topology definition module to power optical devices within the module. 
     In one embodiment, a network topology definition module includes a module housing having an interior. The module housing includes a connector that detachably connects the module housing to a fiber optic interface port of the computing architecture. A plurality of fiber optic terminals and at least one electrically passive optical device are in the interior of the module housing. An optical interconnect(s), for example fiber optic cable(s) or an optical waveguide(s), optically connects the fiber optic terminals and the at least one electrically passive optical device. 
     In another embodiment, a system includes a computing architecture that includes a plurality of computing resources. A fiber optic interface port is connected to the computing architecture. In addition, a plurality of network topology definition modules are provided, each module defining a different network topology from the other modules. Each module includes a module housing having an interior, with the module housing including a connector that detachably connects the module housing to the fiber optic interface port. A plurality of fiber optic terminals and at least one electrically passive optical device are in the interior of the module housing, with an optical interconnect(s) optically connecting the fiber optic terminals and the at least one electrically passive optical device. 
    
    
     
       DRAWINGS 
         FIG. 1  is a schematic depiction of a network topology definition module and a computing architecture. 
         FIG. 2  illustrates an example of the network topology definition module and an optical interface port of the computing architecture. 
         FIG. 3  schematically illustrates an example of optical devices within the network topology definition module. 
         FIG. 4  is a cross-sectional view of the network topology definition module and the optical interface port of the computing architecture. 
         FIG. 5  illustrates an example network topology using one network topology definition module. 
         FIG. 6  illustrates an example network topology using a different network topology definition module. 
         FIGS. 7 and 8  illustrate additional examples of network topologies that can be achieved using different network topology definition modules. 
         FIG. 9  illustrates another example of a network topology definition module. 
     
    
    
     DETAILED DESCRIPTION 
     With reference to  FIG. 1 , a computing architecture  10  and network topology definition module (NTDM)  12  are illustrated which provide the ability to tailor a topology of the computing architecture to differing needs, where the topology of the computing architecture may be changed quickly by replacing the NTDM  12  with a different NTDM  12 . 
     The computing architecture  10  can take on a number of different configurations and can be designed for use in a large number of applications where tailorable computing topology is desirable. Examples of applications include, but are not limited to, environments where hardware subsystem topology must be reconfigured/redistributed to support multiple mission scenarios, space constrained computing environments where hardware subsystems need to be shared, and hardware manufacturing, testing and diagnostics applications. One example environment where the computing architecture  10  can be used is on an aircraft such as fighter aircraft. 
     In the example illustrated in  FIG. 1 , the computing architecture  10  includes a plurality of computing resources, including a processor chassis  14  and a plurality of separate subsystems  16  connected to the chassis  14 . As used herein, the term “computing resources” is intended to encompass resources that actually perform computing functions, i.e. perform mathematical and/or logical operations, such as a processor, as well as encompass resources, both hardware and software, that are non-computing, i.e. do not perform mathematical and logical operations, such as gateways, sensors, switches, radios, and other resources that may be used in conjunction with resources that perform computing functions. 
     The chassis  14  comprises a plurality of individual processors  18 , a plurality of gateways  20 , an optical interface port  22 , and a plurality of gateway input/output interfaces  24 . The processors  18  can be any combination of general purpose and/or specific purpose processors used in computing architectures including, for example, general purpose processors, data processors, graphics processors, and digital signal processors. Although five processors  18  are illustrated, any number of processors  18  can be provided, including one processor and more than five processors. 
     The gateways  20  are any means, implemented in hardware and/or software, capable of interfacing the chassis  14  with the subsystems  16 . An example of a gateway includes, but is not limited to, a router, switch or a media converter. Although two gateways  20  are illustrated, any number of gateways can be provided, include one gateway and more than two gateways. 
     The optical interface port  22  is connected to the processors  18  and the gateways  20  allowing optical inputs and optical outputs. The optical interface port  22  is designed to connect to the NTDM  12  to change the network topology and communication connectivity between the processors  18 , the gateways  20  and the subsystems  16 . Further details on the optical interface port  22  are described below with respect to  FIGS. 2 and 4 . 
     The gateway I/O interfaces  24  interface the gateways  20  with the subsystems  16 . The interfaces  24  can be electrical or optical, but are preferably optical interfaces with a construction similar to the interface port  22 . In the illustrated embodiment, the number of interfaces  24  is equal to the number of gateways  20  and to the number of subsystems  16 . However, to reduce the number of interfaces, the gateways and the subsystems can share a gateway interface  24 . 
     An external I/O interface  25  can also be connected to the interface port  22  to permit other equipment, for example test equipment, to be connected to the network. The interface  25  is optional depending upon whether one wants the ability to connect external equipment to the network. 
     The subsystems  16  are any component(s) that can be attached to the chassis  14  including, but not limited to, sensors, processors, switches, radios, displays, storage devices, printers, servers, scanners, voice over IP systems, workstations, personal computers, etc. A subsystem  16  can be a single component or multiple components, and each subsystem can have different components. The subsystems  16  are separate from each other and any number of subsystems  16 , including none, can be provided. 
     Instead of being in a separate subsystem, some of the components can be included on the chassis  14 , eliminating the need for a gateway to interface directly to the NTDM  12 . 
     The NTDM  12  is a device that is configured to be removably attached to the interface port  22  for determining the topology of the architecture  10 . The NTDM  12  is provided with one or more electrically passive optical devices that determine the resulting network topology and communication connectivity between the various computing resources. The optical devices, and the entire NTDM  12 , are electrically passive, eliminating the need to route electrical power to the NTDM  12 . This simplifies the construction of the NTDM  12 , and facilitates replacement of the NTDM  12  by a different NTDM  12  having differently configured optical devices to result in a different network topology and communication connectivity between the various computing resources. Thus, by having a number of differently configured NTDMs  12 , the network topology can be quickly and easily changed by replacing one NTDM  12  with an NTDM  12  that provides the desired topology. 
     The optical device(s) in the NTDM  12  can be any device(s) suitable for achieving the desired network topology and communication connectivity between the various computing resources. To help explain the concept of the NTDM  12 , the optical devices in the NTDM will be described as being an electrically passive optical star/coupler  30  together with a plurality of filter arrays  32  as illustrated in  FIG. 3 . 
       FIG. 5  illustrates an example network topology  50  using one NTDM, where the topology includes three of the processors  18  and one gateway  20  in communication via the star/coupler  30 .  FIG. 6  illustrates an example network topology  60  using a differently configured NTDM, where the topology includes two of the processors  18  and a gateway  20  in communication via the star/coupler  30 . 
       FIG. 7  illustrates a network topology  70  where two networks are formed from a single NTDM, with each network including two processors, a radio and two sensors in communication via the star/coupler. 
       FIG. 8  illustrates a network topology  80  where three networks are formed from a single NTDM. One network includes a processor, two radios and a sensor. The second network includes a processor and two sensors. The third network includes two processors and a sensor. 
     With reference now to  FIGS. 2-4 , a specific example of the NTDM  12  and the interface port  22  are illustrated. The interface port  22  is of conventional construction including a port body  100  having exterior connection threads  102 . The interior of the port body  100  includes a wall  104  having a plurality of fiber optic terminals  106 , for example sockets, and a pair of alignment pins  108  extending from the wall  104 . The inner surface of the body  100  includes alignment structure  110 , in particular alignment slots, designed to receive mating alignment structure, in particular alignment ribs, on the NTDM  12  to facilitate correct positional alignment of the NTDM  12  and the port  22 . The port  22  is mounted on a suitable support structure  112 , for example a wall or bulkhead when used on an aircraft. The port  22  is connected via fiber optic cables  114  or other optical interconnect means to the computing resources, such as the processors and the gateways, whereby optical inputs and optical outputs are routed through the port  22 . 
     Each NTDM  12  includes a generally cylindrical module housing  120  having an interior  122 . The NTDM includes a connector  124  on the module housing  120  that detachably connects the module housing  120  to the interface port  22 . Any type of connector  124  that can connect the housing  120  to the port  22  can be used. In the illustrated example, the connector  124  is a sleeve that is rotatably mounted on the module housing  120  for rotation relative to the housing. The sleeve includes interior threads  126  engageable with the exterior threads  102  of the port  22  to connect the NTDM to the port when the sleeve is rotated in the correct direction. Other types of connectors, for example a bayonet type connector, can be used instead of threads. 
       FIG. 9  illustrates an example of a NTDM  200  that is provided with two connectors  202 ,  204  that function similarly to the connector  124  so that each connector  202 ,  204  is configured to connect the NTDM  200  to separate interface ports  206 ,  208 , similar to the port  22 , on computing architecture  210 . The use of two connectors  202 ,  204  is useful in situations where there are too many termini to fit into a single connector. 
     In another alternative embodiment of an NTDM, the second connector  204  can be provided at the opposite end of the NTDM as illustrated in dashed lines in  FIG. 9 , in which case each end of the NTDM housing would be open to allow access to optical termini. This type of configuration would allow the NTDM to connect to another NTDM or to other equipment. 
     When two connectors are used, the connectors need not be the same type of connector. For example, one connector can be a female connector and one connector can be a male connector, or one connector can use threads and one connector can be a bayonet type connector. 
     A wall  128  is fixed in the interior  122 , and a plurality of fiber optic terminals  130 , for example pins, are mounted on the wall  128 . The pins extend from the wall  128  for mating engagement within the sockets of the port  22 . Because they are mounted on the wall  128 , the terminals  130  are fixed in the module housing  120  so that the terminals are not movable relative to the module housing. Alternatively, the NTDM could be provided with sockets as the terminals  130 , while the port  22  is provided with pins as the terminals  106 . Alignment holes  132  are formed in the wall  128  and receive therein the alignment pins  108  of the port  22 . In one example, the connector of the NTDM complies with MIL-STD-38999. In another example, the terminals  130  comply with MIL-PRF-29504. 
     At least one electrically passive optical device  134  is disposed in the interior  122  of the module housing  120 . As discussed above, the optical device  134  can be the star/coupler  30  by itself, or together with the filter arrays  32  as illustrated in  FIG. 3 . An optical interconnect(s)  136 , for example fiber optic cable(s) or optical waveguide(s), optically connect the fiber optic terminals  130  and the optical device  134  to pass optical signals between the terminals  130  and the device  134 . 
     In addition, alignment structure  138 , in particular alignment ribs, are provided on the housing  120  to engage with the alignment structure  110  on the port  22  to facilitate correct positional alignment of the NTDM  12  and the port  22 . 
     The NTDM  12  and port  22  could have other configurations. For example, the alignment structure  138  on the NTDM could be the alignment slots, while the alignment structure  110  on the port could be the ribs. In addition, the NTDM could have the alignment pins  108  while the port  22  has the alignment holes  132 . 
     In use, the NTDM  12  providing the desired network topology is selected. The NTDM is then secured onto the port  22  by first aligning the alignment structures, bringing the NTDM into engagement with the port  22 , and then using the connector  124  to detachably secure the NTDM to the port  22 . The NTDM determines the topology of the computing resources available in the computing architecture  10 . If it is desired to change the topology, for example to reconfigure the topology to support a new mission requirement, the first NTDM is removed, and a new NTDM providing the desired topology is secured to the port  22 . 
     The examples disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.