Abstract:
The invention refers to a telecommunications system comprising a module rack that defines a core bay, a service plane and a rack interface plane where the service plane is transverse to the rack interface plane. The core bay is in part bounded by the service plane and the rack interface plane. The telecommunications system also comprises a series of electronics modules each defining an electronics orientation plane where each of the modules includes two opposed cooling surfaces oriented substantially parallel to the electronics orientation plane. Each of the electronics modules is removably secured within the core bay. The series of the electronics modules forms an array such that their electronics orientation planes are substantially perpendicular to both the rack interface plane and the service plane. The array also defines at least one coolant stream passage across each cooling surface. Further the telecommunications system includes a coolant movement means for moving a coolant through the coolant stream passages and across the rack interface plane. As such, the coolant convects heat away from the cooling surfaces of electronics modules more efficiently and effectively than found in the prior art as it, amongst other things, shortens the distance over which the inlet coolant is required to travel to cool the same functional density and provides a coolant to the passage at approximately a uniform temperature for each module.

Description:
FIELD OF THE INVENTION 
     The invention relates to a telecommunications system. 
     BACKGROUND OF THE INVENTION 
     In the digital communications, telecommunications and data processing industries, equipment racks are used to house and organize modules, each of which are used to manage incoming and outgoing and telecommunications and digital data as well as computer generated data. Collectively, the equipment racks along with the housed equipment are known as telecommunications systems. Generally, these telecommunications systems are found as a series of adjacent systems warehoused in service facilities. As such, the objective is to compact as much processing or functional capability within as small a space as possible. Ultimately, costs increase as the volume required to house a given amount of data processing functionality increases. Moreover, any increase in the distance required to transmit telecommunications or other data signals will result in a corresponding decrease in the bandwidth available to those signals. In other words, an objective in the telecommunications, digital communications and data processing industries is to secure an ever higher functional density. 
     Each telecommunications system is made up of a rack outlining a core bay into which a number of data processing modules are supported. While there exists different modules for different functional objectives, each module generally consists of a circuit board encased in a protective housing. The circuit board processes telecommunications data and other digital or computer data. As these circuit boards require power to operate, they ultimately convert some of that energy supplied into heat. However, the circuit boards must be kept within a certain temperature range to operate properly and, as such, an important consideration in telecommunications systems has been the ability to manage heat generated by these circuit boards in operation. 
     While heat generation in a telecommunications system was always an important factor considered in designing such systems, historically, in general it has tended to be the case, that the limiting factor in regards to functional density has been the ability in compact a desired density of data pressing electronics into a given space as opposed to the management of heat generated by the electronic in question. That is, it has tended to be the case that heat generation as a function of processing capability per unit volume was not historically a functional limiting concern. 
     Originally, heat generation was managed by simply orienting modules generally in a vertical column such that air heated by the modules could easily rise between modules convecting heat up and away from the telecommunications systems. This decision directed the industry standard that has defined the gross architecture of these systems. As technology has progressed, heat management has had to be facilitated by a forced air system wherein air was directed through vertical columns between vertically oriented modules and away from the telecommunications system. 
     In recent years, however, there has consistently been a the dramatic increase in functional density in regards to the reduction in space required for an amount of data process capability. At the same time, the power required to operate each module and the consequent heat generated has correspondingly increased in nearly as dramatic a fashion to the point where traditional vertically oriented or end-on-end oriented eletronics modules within a telecommunications systems have been or will soon be unable to realize the advantages of the functional densities now achievable. That is, given the current scale of the racks used, namely on the order of 7 feet in height, it has become difficult to maintain module temperatures within the required range using forced air cooling methods while the modules are vertically oriented along the height of the racks in an end-on-end series of columns. While alternatives have been proposed to better manage heat through such vertical columns of modules, these alternatives suffer significant drawbacks. For example, one alternative proposes the introduction of multiple air or coolant inlets and outlet along the length of the column. Unfortunately, it is very difficult to avoid co-mingling of heated coolant that has convected some heat away from downstream modules with introduced coolant at ambient or chilled temperatures. As such, the introduced coolant must serve the dual purpose of cooling already warmed coolant as well as further upstream modules. 
     A further alternative in the prior art proposes directing coolant across the service plane or front face of the telecommunications system, cooling the modules and exhausting the heated coolant out of the system through the rear plane of the system. This method of cooling, however, requires exhaust outlets through the backplane or midplane into which the electronics modules are removably secured and through which the electronics modules may receive or transmit data. The inclusion of such exhaust outlets in the backplane or midplane naturally uses up space that might otherwise be used for electronic circuitry or components thereby limiting the functional density of the system as a whole. 
     Ultimately, functionality for a given module and therefore for telecommunications systems has been or is soon expected to be limited by the ability of network or data processing providers to maintain each module within a required operating temperature range. 
     Further, vertical orientation of modules has resulted in a need to arrange what has become the industry standard for transporting telecommunications, digital communications or computer generated data into modules, namely, fibre optic cables, in such a way that they must be directed through at least two bend points in order to he routed away from a given telecommunications system to a cable management facility. This was not much of an issue, historically, when the space required for a set of electronic components to process a given amount of data was relatively larger than it is today and, as a result, the relative number of data transports into a module was small. However, with the ever increasing density of electronic functionality within a given volume resulting in the ability to handle ever increasing volumes of data, the number of transports or fibre-optic cables into a given telecommunications system has increased. As such, cable management in the telecommunications system has become cumbersome given the multi-bend routing required to direct cables out of the telecommunications system into a cable management facility. 
     Also, the bundling found in these prior art vertically oriented systems requires cabling from a given set of modules to be co-bundled in some cases before being transported out of the telecommunications system to a cable management facility. Cable maintenance often involved the tedious process of finding and separating specific cables or even fibres associated with a given modules out a bundle of multiple cable from various modules, all of which often had to be done remotely from the telecommunications system. 
     Also, telecommunications systems generally include electronics modules that dominate the signal processing in a telecommunications system, and switch modules, used to provide a method of communicating between electronics modules. In the telecommunications industry these electronics modules are known, for many applications, as access modules. As inferred above, traditional vertical electronics module orientation required an interface between the electronics and switch modules which included, for peripheral electronics modules, longer signal transports than needed for electronics modules that happened to line-up adjacent to a given switch module. The peripheral signal transports suffered reduced bandwidths, and, as such, reduced functionality. 
     The present invention deals with the problems noted above. In short it allows for the main processing modules or electronics modules to be reconnected to deal with these problem. Moreover, in an embodiment of the invention the basic general architecture that defines industry standard core bays in the digital communications and telecommunications industries may be utilized allowing an ease of conversion from telecommunications systems currently found in the telecommunications and digital communications industries. 
     Such reorientation of the electronics modules allows for a means of significantly improving heat management of electronics modules, cable management within a telecommunications system and data transfer between switch and electronics modules. 
     According to one aspect of the invention, there is provided a telecommunications system. The telecommunications system comprises: (a) a module rack providing a core bay and defining a service plane and a rack interface plane, wherein the service plane is transverse to the rack interface plane and the core bay is in part bounded by the service plane and the rack interface plane; (b) a series of electronics modules each defining an electronics orientation plane, each of the electronics modules including two opposed cooling surfaces oriented substantially parallel to the electronics orientation plane, each electronics module being removably secured within the core bay, the series of electronics modules forming an array such that their electronics orientation planes are substantially perpendicular to both the rack interface plane and the service plane, the array defining a plurality of coolant stream passages extending across the cooling surfaces defined by said electronics modules, the coolant stream passages being implemented by and between adjacent modules of the array, with the coolant stream passages thus defined being parallel to one another and transverse to the rack interface plane and providing uniform cooling capacity; and (c) a coolant mover for moving a coolant through the coolant stream passages and across the rack interface plane thus convecting heat away from the cooling surfaces of the electronics modules. 
     BRIEF DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the invention is a telecommunications system comprising a module rack that defines a core bay, a service plane and a rack interface plane where the service plane is transverse to the rack interface plane. The core bay is in part bounded by the service plane and the rack interface plane. A second component of this preferred embodiment is a series of electronics modules each defining an electronics orientation plane where each of the modules includes two opposed cooling surfaces oriented substantially parallel to the electronics orientation plane. Each of the electronics modules is removably secured within the core bay. The series of the electronics modules forms an array such that their electronics orientation planes are substantially perpendicular to both the rack interface plane and the service plane. The array also defines at least one coolant stream passage across each cooling surface, with the coolant stream passages running parallel to one another and transverse to the rack interface plane. The third component of this embodiment of the telecommunications system is a coolant movement means for moving a coolant through the coolant stream passages and across the rack interface plane. As such, the coolant convects heat away from the cooling surfaces of electronics modules. This embodiment provides a more efficient and effective means of moving heat from the electronics modules than found in the prior art as it, amongst other things, shortens the distance over which the inlet coolant is required to travel to cool the same functional capacity. 
     A further embodiment of the telecommunications system orients the modules horizontally thus utilizing the industry standard for core bays found in the digital communications and telecommunications industries. As such, conversion to telecommunications systems as taught, should be relatively straightforward and inexpensive. Moreover, the utilization of the basic architecture of telecommunications systems currently being used will help to facilitate future upgrades in regards to the cooling system utilized. By placing an adjunct bay facilitating the cooling means immediately proximate the core bay, as taught in one embodiment of the invention, it will be easier to remove and upgrade these cooling bays. Finally, utilizing this architecture also provides for a easier method of routing fibre optics cables away from the core bay and electronics module to a cable management facility. 
     A further embodiment of the telecommunications system ensures that the coolant provided to the modules is of substantially equal temperature entering the coolant stream passages. 
     A further embodiment of the telecommunications system provides for a adjunct bay adjacent to the core bay to house the coolant movement means. As such, each telecommunications system is accompanied by an independent coolant means that is easily serviced and easily upgradeable and provides greater redundancy to the cooling system that a central unit may lack. 
     A further embodiment of the telecommunications system provides for an air mover as the coolant movement means. 
     A further embodiment of the telecommunications system provides additionally for a midplane structure that defines a frontal and rear face where the midplane structure is secured in the core bay such that the frontal face is oriented towards and is parallel to the service plane. It further includes at least one switch module where the switch module is secured in the core bay transverse to the electronics orientation planes defined by the electronics module. The switch module is also parallel to the interface plane. The switch module is, moreover, in communication with the electronics modules through the midplane structure. This allows for the switch modules to be placed adjacent to a series of electronics modules across the midplane structure, thereby, increasing the overall bandwidth available between the switch and electronics modules. 
     A further embodiment of the telecommunications system further includes a cable transport abutting the module rack where the cable transport is adapted to direct a series of data carrying cables from the electronics modules to a cable management facility. 
     Still a further embodiment of the telecommunications system allows for a slack storage unit positioned between the cable transport and module rack that includes a series of rows corresponding to each of the electronics modules. The series of rows extend from the module rack to the cable transport and house bundles of cable and a service area for cables. The slack storage unit directs the cables from the electronics modules through to the cable transports, where the cable transport directs the cable to a cable management facility. 
     A further embodiment of the telecommunications system includes a telecommunications system that comprises the module rack and electronics modules considered in the first embodiment but includes a coolant movement means that moves a coolant through the coolant stream passages and across the rack interface plane thus convecting heat away from the cooling surfaces and the electronics modules. This embodiment allows for alternatives to air cooling for the modules and, with a further inclusion of the adjunct bay, a place to house the coolant movement system. 
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of the prior art telecommunications systems. 
     FIG. 2 is a front view of a preferred embodiment of a telecommunications system. 
     FIG. 3 is a rear view of a preferred embodiment of a telecommunications system. 
     FIG. 4 is a front schematic view of a preferred embodiment of a telecommunications system. 
     FIG. 5 is a back schematic view of a preferred embodiment of a telecommunications system. 
     FIG. 6 is a side schematic view of a preferred embodiment of a telecommunications system along the line of A—A of FIG.  4 . 
     FIG. 7 is a top schematic view of a preferred embodiment of a telecommunications system along the line of B—B of FIG.  4 . 
     FIG. 8 is a back cross sectional view of a preferred embodiment of a telecommunications system along the line C—C of FIG.  6 . 
     FIG. 9 is a cross-sectional view of an electronics module. 
     FIG. 10 is a perspective view of a preferred embodiment of an electronics module. 
     FIG. 11 is a top-cut view of the midplane at the module interconnection point. 
     FIG. 12 is a front view of a telecommunications system including an alternative cable transport. 
     FIG. 13 is a front view of a telecommunications system including a slack storage facility and cable transport. 
    
    
     DETAILED DESCRIPTION 
     Referring to FIG. 1, the telecommunications system found in the prior art shows vertically oriented electronics modules  20  supported in a core bay  22 . Generally, the dimensions of the core bay have evolved over the last decade from the need to utilize as much space within a service room as possible while maintaining workable dimensions and weight for the electronics modules such that service personnel could easily handle the modules. 
     Referring to FIGS. 2,  4 ,  6 ,  7  and  9 , a preferred embodiment of the system is shown where, focussing on the core bay  24  of the telecommunications system  26 , a series of the electronics modules  28  are aligned in the core bay  24  when the telecommunications system  26  is in its operational position. In the embodiment shown, although the invention is not limited to this configuration,  16  electronics modules  28  are stacked in a given core bay  24 , where two core bays are shown, one stacked on top of the other. 
     The basic configuration described above utilizes the basic dimensions of the prior art telecommunications systems  26  found in digital communication and telecommunications industries. That is, the present invention teaches a telecommunications system  26  that can utilize the same basic facilities utilized to house these systems. While these physical dimension do not limit the invention, they do allow a ease of conversion to the telecommunications system taught, that would not otherwise exist. 
     Each module  28 , as seen in FIGS. 7 and 9, has an encasing  30  adapted to conduct heat away from the internally housed electronic and optical devices  32 . In a preferred embodiment as shown, the heat is conducted to extended surfaces or lins  34  on the cooling surface  36  to define a series of coolant stream passage  38  wherein a coolant such as an airstream  40  at ambient room temperature may be directed to convect heat away from the cooling surfaces  34 . The cooling surfaces  36  or heatstinks can be constructed from an aluminum alloy housing, however, other suitable conducting material can also be used. 
     Moreover, alternate methods may be employed for convecting heat away from the electronics modules. For example, an alternate embodiment may include introducing a chilled airstream into the coolant stream passages  38 . Also, the cooling surface may be a cold plate wherein a cooling medium is circulated. 
     Generally, again referring to FIG. 7, a coolant movement means directs a coolant over the cooling surfaces  36  or heatsinks. In the embodiment shown, the coolant movement means that forms part of the telecommunications system in a series of air movers  42  that are housed in a adjunct bay  44  situated adjacent to the core bay  24 . The air movers  42  create a low pressure plenum  46  immediately adjacent to the core bay  24  and, as such, immediately adjacent the array of modules  28 . Specifically, referring to FIG. 8, ambient air is directed from an inlet plenum  48  across the module cooling surfaces  36  through one or more coolant stream passages  38  into a low pressure plenum  46  created by the air movers  42 . It is advantageous for the air to be introduced to each stream passage  38  at approximately the same temperature, thereby provided the same cooling capability across the stream passages  38  into the low-pressure plenum  46 . The air movement system is a “pull” system. Air enters into the stream passages and across the cooling surfaces  36  of the electronics modules  24  and is drawn into the adjunct bay  44 . The convecting air  40  or other suitable coolant is then expelled to an exhaust plenum  50  within the adjunct bay  44  convecting a portion of heat generated by the electronics modules  28  out of the telecommunications system  26 . 
     By providing adjunct bay housing  52  and core bay housing  54  that is functionally integrated but physically separable, the mobility and interchangeability of these units of the preferred embodiment shown is enhanced. 
     In the embodiment shown, three air movers  42  are secured in each adjunct bay  44  and associated with each core bay  24 . 
     Note that the coolant movement means is not limited to the embodiment shown. Other means of directing air or any other suitable coolant across the cooling surface of each module will also work. These might include a coolant movement system remote from the core bay that creates a low pressure plenum adjacent to the array of modules. Moreover, while the creation of a low pressure plenum downstream of the electronics modules helps to provide uniform convection of heat away from all the electronics modules, any other means of directing a coolant across the cooling surfaces or heatsinks of the electronics modules will also work. That might include the creation of a high-pressure plenum adjacent to the modules array “pushing” coolant across the heatsinks or cooling surfaces. Care, in this situation must be taken however, to ensure a relatively uniform distribution of coolant across all cooling surfaces. 
     Additionally, an alternate embodiment, wherein the cooling surfaces are cold plates as noted above, would provide for a means of circulating a cooling medium through the cold plates. The orientation of the electronics modules, however, would allow the circulating means to be secured in the adjunct bay adjacent to the module array. As such, the conduits required to transport the cooling medium could be directly routed to the circulation means. All electronics modules cooling surfaces would be easily accessible and to some degree equidistant from the circulating means. The same idea can also be utilized where the adjunct bay is removed and the means for circulating the coolant is housed remotely forcing coolant through the arrays in one or several telecommunications systems. 
     In the embodiment shown, and referring to FIGS. 7 and 9, the coolant stream passages are created from a series of cast fins  34  that provide passages  38  along the cooling surface  36  of each module, however, other suitable structures that allow air or another coolant medium to be relatively uniformly drawn across the conductive cooling surfaces  36  will also suffice. 
     While the cooling surface noted in the embodiment disclosed includes integral cast fins  34  and can dissipate on the order of 350W per electronics module utilizing ambient room air, this is not the only embodiment that will provide the required heat convection solution. An enhanced heatsink may also be used. Improved heat transfer performance can be achieved by decreasing the thickness of the fins and placing more of them on a tighter pitch. Fins can be interrupted and offset at intervals along their length to break up the boundary layer and optimize heat transfer. 
     In the embodiment of the invention noted above, air movement into the low-pressure plenum  46  other than through the coolant stream passages  38  as shown, should be minimized. As such, the system as a whole should demonstrate minimal loss through the core bay  24  or adjunct bay  44  in order to maximize the mass transport of air around the cast fins  34  and through the coolant stream passages  38  and, therefore, maximize the dissipation of heat away from the electronics modules  28 . In the embodiment shown, leakage is controlled by applying environmental gaskets to seal cracks occurring due to loose tolerance fits or due to removable covers. 
     Note, where the coolant is air, as it is directed across a sealed module, no air filters are required. 
     Where the coolant used to convect heat away from the cooling surface is air, it should be noted that the degree of cooling provided will be reduced with increased altitude. This should be taken into account considering the location for installation of telecommunications systems utilizing those teachings. 
     Referring to FIGS. 2 and 12, a further embodiment utilizes the advantages of the orientation of the eletronics modules where fibre optics cables  54  may be run from the face plates  56  of the electronics modules  28  and across the electronics modules  28  where they are directed through a cable transport  58  to a cable management facility. The cables  54  while in the embodiment shown are run upwards to a cable management facility, they may equally be directed downwards to a cable management facility. 
     Additionally, referring to FIG. 2, where the cable transport is utilized, a series of channels  60  may included wherein each of the cables  54  are directed from particular electronics module  28  through a channel corresponding with a given module. 
     Further, referring to FIG. 12, an embodiment is shown wherein the orientation of the electronics modules  28  allows for any cable  54  that may be associated with a given module to be routed into the cable transport  58  to bundle grouping facilities within the transport  58  that provide a means of bundling and grouping associated cabling prior to routing the cable to the cable management facility. 
     A further embodiment, referring to FIG. 13, shows how the orientation of the electronics modules allow for cabling to be routed through a slack storage unit  62  before being directed on to the cable transport  58 . As such, cables  54  associated with a given module may be directed in to the slack storage unit  62  where excess cabling can be bundled or spooled. Also the slack storage unit  62  allows an area for service personnel to work with the cabling associated with a given module  28  including working with cable breakout. This also allows a work area and bundling area  64  near the termination point of the cables  54  that was not previously available. 
     The electronics modules  28  will generally be stacked in a vertical array where the modules will be oriented horizontally as noted in the FIGS. 2,  4  and  6 . This is due to the practicalities that arise from such an orientation. That is, the telecommunications and digital communications industries have developed and defined telecommunications systems that generally conform to a vertically oriented core bay that is approximately 3 to 4 times higher than the core bay width or depth. As such, the advantages noted arise from being able to convert to systems that follow the teachings enclosed herein while maintaining the same gross dimensions of telecommunications systems found in the telecommunications and digital communications industries. As such, a generally vertical array of horizontally oriented electronics modules set in the core bay of these standard system structures meets this objective. 
     As such, reference to horizontal orientation of the electronics modules refer to embodiments directed at utilizing this existing infrastructure. That is, horizontal and vertical orientation references as used in this disclosure are in relation to a standing core bay wherein a vertical array of horizontally oriented electronics modules are placed. The invention, however, is not limited to a vertical array of electronics modules, all horizontally oriented. Some of advantages stated will, generally, be realized with a horizontal array of vertically oriented electronics modules, or any relative orientation in between, where coolant is directed over the cooling surfaces of the modules into a plenum situated proximate the array. While some of the advantages in regards to cable management, cooling efficiency and the ability to manipulate and upgrade the system may be lost, some of the heat management advantage may still enjoyed. 
     Referring to FIGS. 3,  5  and  11 , the present invention allows for advantages to be derived from the orientation taught of the electronics modules  28 , wherein an embodiment of the telecommunications system  26  includes switch modules  66 . In such an embodiment, one or a set of switch modules  66  may be secured within the core bay  24  behind the electronics modules  28 . In such an embodiment a midplane  68 , (a “midplane structure” that is a structure that is positioned around the mid plane of the core bay) is positioned and secured within the core bay  24  perpendicular to the electronics modules  28  and running across and adjacent the electronics modules  28 . The electronics modules  28  should then be secured to the midplane  68  from the front face  70  of the telecommunications system. Behind the midplane  68  are one or more switch modules  66 . In the embodiment shown, although not a limiting feature, six switch modules are included. These modules  68  are then oriented transverse to the orientation of the electronics modules  28 . Communication between the electronics modules  28  and the switch modules  66  is then facilitated across the midplane  68 . Given the orientation of the electronics modules  28  transverse to the switch modules  66 , a cross-hatching configuration is created at the interface of the two sets of modules found on either side of the midplane  68 . Therefore, the switch modules  66  are positioned within the core bay  24  such that they are proximate to each electronics modules  28  within a given array of such modules on the opposing side of the midplane  68  resulting in a relatively short interface between both sets of modules. As a result, the signal bandwidth across the midplane  68  is increased, on average. 
     As a result of the placement of the switch modules  66  towards to the back side of the telecommunications system  26 , there may be a requirement to provide access to the back side  72  in such embodiment in order to allow service personnel access to these modules  66 . 
     Considering the specific embodiment of the intersection points  74  on a midplane shown in FIG. 11, at each intersection point  74  between a given electronics module  28  and a given switch module  66 , 40 pairs may be routed between the two modules:  20  Transmit and  20  Receive. 
     Moreover, referring to FIGS. 7 and 8, the coolant movement means  42  can be used to direct the coolant across coolant surfaces  76  found on the switch modules  66  thus convecting heat away from the switch modules  66 . As the number of switch modules  66  is less than the electronics modules  29 , the relatively convoluted route over which the coolant is required to travel, as seen by the arrow shown in FIG. 8, should not affect the ability of the coolant movement means  42  to effectively convect the heat generated by the switch modules  66  out of the telecommunications system  26 . 
     Note that the midplane and midplane structure are used interchangeably. 
     Referring to FIG.  10 . in regards to the switch modules  66  and electronics modules  28 , while generally shielded in a heat conductive housing  78 , it is desirable that they be sealed in such a way that allows for little or no electromagnetic leakage. This can be accomplished but is not limited to utilizing the conductive aluminum housing  78  including the cooling surfaces  36  sealing the electronic components along five sides. The sixth side  80  abutting the midplane  68  on both the switch  66  and electronics modules  28  may be sealed to the midplane  68  around the full perimeter when the module is in place. This may be accomplished but is not limited to utilizing a compressible elastomeric gasket fastened to the midplane. 
     Finally, while the terminology and embodiments discussed are directed towards telecommunications system, this by no means restricts the scope of the present invention to what are traditionally telecommunications systems in a very narrow sense. The advantage of the module orientation taught in the present invention extends to data processing and digital or data communications industries as well. That is, the teachings enclosed herein, while they refer to a telecommunications system and disclose an embodiment of a novel telecommunications system, are not restricted to the telecommunications industry in a strict sense. The module orientation taught is applicable where groupings of digital signal processing units are arrayed and require heat and data input cabling management as well as inter-processing unit management. As such, data processing units in the telecommunications industry, digital or data communications industry and data processing industries all benefit and are encompassed by the teachings in the present application. 
     Moreover, the use of the term electronics modules will be understood to include all optical/electronic devices, or data delivery and processing units that generate appreciable heat or utilize significant data input cabling. 
     In order to provide further assistance, and purely for illustrative purposes, some specifications of one embodiment of the invention are provided below. 
     Dimensions of the System with Switch Modules and Stack Storage Unit 
     
       
         
               
               
               
               
             
           
               
                   
                   
               
             
             
               
                   
                 Core Bay 
                   
                   
               
               
                   
                 Width: 
                 600 mm 
               
               
                   
                 Height: 
                 2125 mm 
               
               
                   
                 Depth: 
                 600 mm 
               
               
                   
                 Adjunct Bay 
               
               
                   
                 Width: 
                 600 mm 
               
               
                   
                 Height: 
                 2125 mm 
               
               
                   
                 Depth: 
                 600 mm 
               
               
                   
                 Cable Transport 
               
               
                   
                 Width: 
                 300 mm 
               
               
                   
                 Height: 
                 2125 mm 
               
               
                   
                 Depth: 
                 600 mm 
               
               
                   
                 Cable Slack Storage Unit 
               
               
                   
                 Width: 
                 450 mm 
               
               
                   
                 Height: 
                 2125 mm 
               
               
                   
                 Depth: 
                 600 mm 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Thermal Performance 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Power Dissipation per module: 
                 350 W 
               
               
                   
                 Power Dissipation per Core Bay: 
                 17,200 W 
               
               
                   
                 Maximum ambient operating temperature: 
                 50° C. 
               
               
                   
                 Maximum module heatsink temperature: 
                 70° C. 
               
               
                   
                   
               
             
          
         
       
     
     
       
         
               
             
               
               
               
             
           
               
                   
               
               
                 Air Mover Performance aud dimensions 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Diameter: 
                 225 mm 
               
               
                   
                 Depth: 
                 99 mm 
               
               
                   
                 Air Flow: 
                 625 CFM at free delivery 
               
               
                   
                   
               
             
          
         
       
     
     Midplane Traffic 
     40 high speed controlled impedance signal pairs connected at each of the 128 intersections between the 8 switch modules and the 16 access modules. Each pair is capable of supporting at least 2.5 Gbit/second transmission. This results in a total bi-directional traffic capacity of 6.4 Terabits per second. 
     Numerous modifications, variations and adaptations may be made to the particular embodiment of the invention described above without departing from the scope of the invention, which is defined in the claims.