Patent Publication Number: US-2015077935-A1

Title: Air Filter And Cable Management Assemblies For Network Communication Systems

Description:
TECHNICAL FIELD 
     This disclosed embodiments relate to cooling of electronic equipment and, more particularly, to air cooling of network communication systems. 
     BACKGROUND 
     Cooling is required for many network communication systems and is particularly important when many network communication systems are placed in close proximity to each other. One environment in which this need for cooling exists is within central telecommunication hubs, which often conform to NEBS (Network Equipment-Building System) guidelines. In such environments, air cooling is often utilized to dissipate heat from electrical components within the network communication systems. In addition to this air cooling, filtering of airborne particulates within the airflow is often desirable to avoid build-up of dust particles within a system. A build-up of dust particles can lead to poor airflow, overheating, and increased fire risks. 
       FIG. 1  (Prior Art) is a block diagram of an example embodiment  100  where network communication systems have been organized according to NEBS guidelines. As shown, communication equipment racks  102 ,  106 , and  110  hold network communication systems  104 ,  108 , and  112 , respectively. Typically, each rack will be configured to hold ten or more closely-spaced and stacked network communication systems, and each row will typically include multiple racks. As such, considerable heat can be generated in a relatively confined space when these racks are fully populated with network communication systems. 
     To provide heat dissipation in many such environments, cooled air is forced up through the bottom of the racks  102 ,  106 , and  110  and vented out the top of the racks  102 ,  106 , and  110 . This airflow provides for cooling of the systems mounted within the racks. Alternatively, cold aisles  130 / 132  and hot aisles  134 / 136  can be formed between the rows of network communication systems. The cold aisles  130  and  132  receive cooled air as indicated by arrows  120  and  122 . As shown by arrows  140 ,  142 , and  144 , the airflow passes through the network communication systems  104 ,  108 , and  112  to provide heat dissipation for these network communication systems. The resulting heated air then flows into the hot aisles  134  and  136 . These hot aisles  134 / 136  provide the air return path for the air cooling process as shown by arrows  124  and  126 . 
       FIG. 2  (Prior Art) is a block diagram of an example embodiment for network communication system  104 . For the embodiment depicted, the network communication system  104  includes a connection panel  202 , a cover plate  204 , a shaped filter  206 , an electronics compartment  210 , and fans  208 . The connection panel  202  includes a number of connection ports for communication cables, such as Ethernet and/or other communication cables (e.g., CAT5, CAT6 rated cabling). The cover plate  204  is perforated to allow air to flow through the cover plate  204  and into the compartment  210 . The filter  206  is shaped to fit around the connection panel  202  and to match the shape of the perforated cover plate  204 . The compartment  210  includes the electrical circuitry and components for which cooling is needed. The fans  208  are utilized to help force the airflow  140  into and through the compartment  210 . As shown in  FIG. 1A  (Prior Art), the airflow  140  will enter from the cold aisle  130  and exit into the hot aisle  134 , and the outgoing air will have been heated through a heat exchange process between the cooled air entering the system  104  and the hot electrical circuitry and components within compartment  210 . 
     Difficulties arise, however, with the air cooling solution described above. One difficulty is that the shaped filters and cover plates lead to undesirable complexity, as different network communication systems are often included within a rack with each different system often having a different connection panel configuration. As such, different shaped filters are required for each different system. Further, access is required to the front of each communication system in order to remove the cover plate  204  and replace the shaped filter  206  on each system when it has reached the end of its useful life. As communication cables will typically be attached to the connection panel  202 , the process of replacing the shaped filter  206  is difficult and time consuming, as the cabling must often be removed prior to filter replacement. Further, due to this difficulty, technicians tend to avoid replacing filters, which can then become clogged and restrict airflow into the communication systems. The restricted airflow reduces cooling efficiency and can ultimately lead to equipment failures. 
     SUMMARY OF THE DISCLOSED EMBODIMENTS 
     Air filter and cable management assemblies for network communication systems are disclosed. The assemblies include filters that cover one or more communication line cards and their associated connection panels. The assemblies also include cable support structures with cable support brackets that support connected cables while restricting airflow so that airflow is forced through filters towards the connection panels. This airflow can then pass into housings for the line cards and other circuitry, such as fabric cards, to provide desired cooling. Fan subsystems can also be provided to facilitate airflow. Advantageously, the disclosed air filter and cable management assemblies allow for filtered cooling of stacked network communication systems while greatly simplifying the complexity of the filter and cable installation and maintenance. Other features and variations can be implemented, and related systems and methods can be utilized, as well. 
     Embodiments are disclosed for a network communication system including a connection panel frame having a front surface, at least one communication system coupled to the connection panel frame and having a connection panel accessible from the front surface of the connection panel frame, and a filter and cable management assembly coupled to the connection panel frame. The assembly further includes a cable support structure having at least one cable support bracket positioned along a vertical edge of the connection panel frame and being configured to restrict airflow and to receive communication cables associated with the connection panel, a filter positioned over the connection panel, and a filter housing positioned over the filter to hold the filter in a secured relationship with respect to the cable support structure and the connection panel frame. 
     In further embodiments, a plurality of communication systems are coupled to the connection panel frame, and each of the communication systems has a connection panel accessible from the front surface of the connection panel frame. In addition, at least one cable support bracket can be provided for each connection panel. For other embodiments, the cable support structure can include a first cable support structure having a plurality of cable support brackets positioned along a first vertical edge of the connection panel frame and a second cable support structure having a plurality of cable support brackets positioned along a second vertical edge of the connection panel frame. Further, the communication systems can include a plurality of communication line cards coupled to the connection panel frame and a plurality of fabric cards coupled to the communication line cards. Still further, the system can include a housing including the connection panel frame and holding the line cards and the fabric cards. Also, the system can further include a fan subsystem coupled within the housing. The filter can include a filter frame holding filter media, and the filter media can include a porous filter material. 
     In still further embodiments, the cable support brackets comprise a support body having a void and a gasket positioned within the void. In addition, the gasket can include a foam material, and the foam material can be polyurethane foam. Further, the gasket can be implemented as multiple pieces or as a single piece. Still further, at least a portion of the gasket can be folded to position the gasket within the void. Also, the cable support bracket can be shaped to facilitate insertion of cables into the cable support bracket. 
     Embodiments are also disclosed for a filter and cable management assembly including a cable support structure having at least one cable support bracket configured to be positioned along a first vertical edge of a connection panel frame for at least one communication system having a connection panel and to restrict airflow and to receive communication cables associated with the connection panel, a filter, and a filter housing positioned to hold the filter in a secured relationship with respect to the cable support structure and the connection panel frame. 
     In further embodiments, the cable support structure can include a first cable support structure having a plurality of cable support brackets configured to be positioned along a first vertical edge of the connection panel frame and a second cable support structure having a plurality of cable support brackets configured to be positioned along a second vertical edge of the connection panel frame. In addition, the filter can include a filter frame holding filter media, and the filter media can be a porous filter material. Further, the cable support bracket can include a support body having a void and a gasket positioned within the void. Still further, the gasket can include a foam material, and the foam material can be a polyurethane foam. Also, the cable support brackets can be shaped to facilitate insertion of cables into the cable support brackets. 
     Further embodiments are disclosed for a method for controlling airflow for a network communication system including receiving airflow for a network communication system through a filter and cable management system and exhausting the airflow from the communication system. The filter and cable management system includes a cable support structure, a filter, and a filter housing. The cable support structure includes at least one cable support bracket positioned along a first vertical edge of a connection panel frame for at least one communication system having a connection panel where the cable support bracket restricts airflow and receives communication cables associated with the connection panel. And the filter housing is positioned to hold the filter in a secured relationship with respect to the cable support structure and the connection panel frame. 
     In further embodiments, a plurality of communication systems are coupled to the connection panel frame with each of the communication systems having a connection panel accessible from the front surface of the connection panel frame. In addition, the cable support structure can include a first cable support structure having a plurality of cable support brackets positioned along a first vertical edge of the connection panel frame and a second cable support structure having a plurality of cable support brackets positioned along a second vertical edge of the connection panel frame. Further, the communication system can include a plurality of communication line cards coupled to the connection panel frame and a plurality of fabric cards coupled to the communication line cards. Still further, the exhausting step can be performed using a fan subsystem. Also, the cable support bracket can include a support body having a void and a gasket positioned within the void. 
     Additional and/or different features and embodiments can be also implemented, as desired, and related systems and methods can be utilized, as well. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       It is noted that the appended drawings illustrate only exemplary embodiments and are, therefore, not to be considered limiting of the scope of the invention, for the invention may admit to other equally effective embodiments. 
         FIG. 1  (Prior Art) is a block diagram of an example embodiment for network communication systems within rows of equipment racks. 
         FIG. 2  (Prior Art) is a block diagram of an example embodiment for a network communication system having a shaped filter. 
         FIG. 3  is a block diagram of an embodiment for a network communication system having an airflow and cable management assembly. 
         FIG. 4 . is an expanded view diagram of a more detailed example embodiment for a filter and cable management assembly that can be used with stacked network communication systems. 
         FIG. 5  is a top view diagram of an embodiment showing cable connections exiting through a cable support bracket. 
         FIG. 6  is a collapsed view diagram showing an embodiment for a closed filter and cable management assembly. 
         FIG. 7A  is an exploded view diagram of an example embodiment for a cable support bracket. 
         FIG. 7B  is a collapsed view of the cable support bracket with an inserted gasket. 
         FIG. 8A  is a diagram of an embodiment where a single cable has been inserted into a cable support bracket. 
         FIG. 8B  is a diagram of an embodiment where multiple cables have been inserted into a cable support bracket. 
     
    
    
     DETAILED DESCRIPTION 
     Air filter and cable management assemblies for network communication systems are disclosed. The assemblies include filters that cover one or more communication line cards and their associated connection panels. The assemblies also include cable support structures with cable support brackets that support connected cables while restricting airflow so that airflow is forced through filters towards the connection panels. This airflow can then pass into housings for the line cards and other circuitry, such as fabric cards, to provide desired cooling. Fan subsystems can also be provided to facilitate airflow. Advantageously, the disclosed air filter and cable management assemblies allow for filtered cooling of stacked network communication systems while greatly simplifying the complexity of the filter and cable installation and maintenance. Other features and variations can be implemented, and related systems and methods can be utilized, as well. 
       FIG. 3  is a block diagram of an embodiment  300  for a network communication system having an airflow and cable management assembly  350 . The assembly  350  includes a filter housing  302  that covers and secures a filter  304 . The filter housing  302  can be configured to allow airflow  324  to pass through the filter housing  302  to the filter  304  and ultimately to the connection panel frame  306 . Cable support structures  308  and  310  are positioned with respect to the vertical edges of the connection panel frame  306 . Each cable support structure  308 / 310  includes a number of cable support brackets (CSB1, CSB2 . . . CSBN)  330 ,  332  . . .  334  that are associated with the line cards (LC1 . . . LCN)  312  . . .  314  and that are utilized to support cables attached to the line cards (LC1 . . . LCN)  312  . . .  314 . As described in more detail below, communication cables that are connected to the connection panel for each of the line cards (LC1 . . . LCN)  312  . . .  314  can be guided through the cable support brackets (CSB1, CSB2 . . . CSBN)  330 ,  332  . . .  334  that are located in the cable support structures  308  and  310 . It is noted that the connection panels fro the line cards (LC1 . . . LCN)  312  . . .  314  can include connection ports for one or more types of communication cables and can include perforations or other techniques to allow air to flow through the connection panel and into the interior of the embodiment  300 . Advantageously, the cable support brackets (CSB1, CSB2 . . . CSBN)  330 ,  332  . . .  334  provide a seal around the communication cables such that lateral airflow is restricted thereby forcing incoming air through the filter  304 . It is further noted that embodiment  300  is only an example of how a network communication system can be configured and implemented. For example, the line cards (LC1 . . . LCN)  312  . . .  314  can be placed in vertical orientations, if desired, and a combination of horizontal and vertical orientations could be utilized, as well. Other variations could also be implemented as desired. 
     Looking further to embodiment  300 , it is noted that embodiment  300  includes multiple communication systems that are implemented using line cards (LC1 . . . LCN)  312  . . .  314  and fabric cards (FC1 . . . FCN)  316  . . .  318 . As described herein, each of the line cards (LC1 . . . LCN)  312  . . .  314  has a front connection panel and is attached to the connection panel frame  306  such that its connection panel is exposed to the front surface of the connection panel frame  306 . These line cards (LC1 . . . LCN)  312  . . .  314  include circuitry and connection ports that provide interface connectivity to one or more communication cables. The fabric cards (FC1 . . . FCN)  316  . . .  318  are connected to the line cards (LC1 . . . LCN)  312  . . .  314 . Further, the fabric cards (FC1 . . . FCN)  316  . . .  318  include circuitry that provides network switching functionality for handling network traffic between the line cards (LC1 . . . LCN)  312  . . .  314  and an external backplane that is typically connected the fabric cards (FC1 . . . FCN)  316  . . .  318 . The fan subsystem  320  includes one or more fans that help to pull the airflow  324  through the embodiment  300 . For embodiment  300 , the air flow inlet is through the filter  304 , and the airflow  324  is drawn by the fans which operate as an exhaust for the airflow  324 . As indicated by bracket  322 , the connection panel frame  306  can be a front portion of a housing that encloses the line cards (LC1 . . . LCN)  312  . . .  314 , the fabric cards (FC1 . . . FCN)  316  . . .  318 , the fan subsystem  320 , and any other desired structure or circuitry that is utilized to implement the multiple network communication systems within embodiment  300 . 
     It is again noted that the embodiment  300  is simply one example embodiment and other implementations could be made, as desired, that utilize a filter and cable management assembly as described herein. For example, embodiments can be configured to provide any desired form factor depending upon the desired end use. For example, a single line card could be used within the system where a 1U rack mount height implementation was desired. Other rack heights and form factors could also be implemented using any selected number of line cards and other components, as desired. As such, it should be recognized that additional and/or different components could be utilized, as desired, while still taking advantage of a common filter and cable management assembly for multiple network communication systems and related connection panels. 
       FIG. 4  is an expanded view diagram of a more detailed example embodiment for a filter and cable management assembly  350  coupled to the connection panel frame  306 . For the embodiment depicted, the filter  304  includes a filter media enclosed within an outer filter frame, although other common filter configurations could also be utilized. The filter housing  302  includes an outer frame and an open interior with vertical and horizontal structures, such as wires, to retain the filter  304 . The filter housing  302  can be shaped to fit over the filter  304  and around the cable support structures  308  and  310 . Connectors  402 ,  404 ,  406 , and  408  can be used to secure the filter housing  302  to the cable support structures  308  and  310 . The cable support structures  308  and  310  in turn include a number of different cable support brackets, such as brackets  330  and  410 . As described herein, the cable support brackets are associated with the connection panels for the line cards, such as line card  312 , and are configured to support connected cables exiting the assembly  350 . As further described herein, these cable support brackets provide a seal around the cables to restrict airflow through the brackets. For the embodiment depicted, there are six connection panels for six different line cards, and there are six cable support brackets within each of the cable support structures  308  and  310 . The cables connected to the connection panels are then routed through the cable support brackets. It is further noted that cables can be routed through cable support structure  308  or through cable support structure  310 ; however, it is expected that half of the cable connections would use cable support structure  308  and the other half would use cable support structure  310  depending which is closest to the connection port. 
     It is noted that the filter media for the filter  304  can be implemented, as desired. In particular, the material and the material thickness for the filter media can be selected based upon various factors, such as particle filter size desired, amount of particulate removal desired, allowable airflow resistance, and/or other factors. One filter media that can be utilized is a one-half inch thick Quadrafoam porous filter having 25 PPI (pores per inch) available from Universal Air Filter. Such a filter media can remove greater than 80% of dust particles from the airflow while still providing relatively low airflow resistance, which improves airflow and reduces operational stress on the fan subsystem  320 . The filter frame for the filter  304  can be sized and configured to match the filter housing  302  and to produce any desired shape for the filter  304 , as desired. The filter housing  302  can be implemented, for example using a thin sheet of metal (e.g., 0.08 inch thick aluminum sheet) that has been shaped to fit around the cable support structures  308 / 310  and the filter  304 . Variations could also be implemented, as desired, while still utilizing a common filter structure covering multiple connection panels, as described herein. 
     It is further noted that strips of air flow resistant material, such as strips of foam material, can be positioned on the back edges of the filter housing  302  that face and engage with the connection panel frame  306  and cable support structures  308 / 310 . When the assembly is completed, these strips of air flow resistant material will form a seal that restricts and preferably eliminates air from seeping in at the connection seams for the filter housing  302 . In this way, air flow is forced through the filter  304  rather than being allowed to bypass the filter  304  by entering through a connection seam for the housing  302 . 
       FIG. 5  is a top view diagram of an embodiment  500  showing cable connections exiting through the cable support bracket  330 . For the embodiment depicted, there are no cables connected and exiting through the cable support bracket  410 , although it is understood that such connections could be made, if desired. As also depicted, the filter  304  is located in front of the connection panel for the line card  312 . The filter housing  302  holds the filter  304  in place. As described above, the connectors  402  and  408  are utilized to secure the filter housing  302  to the cable support structures  308 / 310 . 
       FIG. 6  is a collapsed view diagram showing an embodiment  600  for the closed filter and cable management assembly  350  coupled to the connection panel frame  306 . As depicted, the filter  304  is held in place in front of the connection panels by the filter housing  302 , and the filter housing  302  is secured in place by connectors  402 ,  404 ,  406 , and  408 . As also depicted, communication cables connected to the line cards exit through the cable support brackets, such as cable support bracket  330 , within the cable support structure  308 . 
       FIG. 7A  is an exploded view diagram of an example embodiment for a cable support bracket  330 . For the embodiment depicted, the cable support bracket  330  includes a support body  702  having a void  704  configured to receive a gasket  708 . The support body  702  also includes a shaped opening  706  configured to facilitate the insertion of cables. The support body  702  can also have a connection mechanism to allow the support body  702  to be attached to the panel connection frame  306  or related structure. For example, holes  710  can be formed or otherwise provided within the support body  710  to allow for screws or push tabs to be used to attach the support body  702  to the panel frame  306 . Other attachment mechanisms and structures can also be used, as desired, that allows for multiple support brackets to be positioned and secured to form the cable support structures  308  and  310 . 
       FIG. 7B  is a collapsed view of the cable support bracket  330  with the gasket  708  inserted and secured within the void  704 . The resulting cable support bracket  330  is configured to receive cables into gasket  708  through opening  706 . As described above, the back portion of the support body  702  can be secured as part of the cable support structure  308  using any desired attachment mechanism. 
       FIG. 8A  is a diagram of an embodiment  800  where a single cable  802  has been inserted through the opening  706  for the support body  702  and into the gasket  708 . As shown, the cable  802  is secured within the gasket  708 , which forms a seal around the cable  802 . This seal restricts external air from flowing through the cable support bracket. 
       FIG. 8B  is a diagram of an embodiment  850  where multiple cables  852  have been inserted through the opening  706  for the support body  702  and into the gasket  708 . As shown, the cables  852  are secured within the gasket  708 , which forms a seal around the cables  852 . This seal again restricts external air from flowing through the cable support bracket. 
     It is noted that the support body  702  and the gasket  708  can be formed and shaped using a variety of techniques while still achieving the desired result of restricting airflow through the cable support bracket  330  by forming a seal around cables inserted into the cable support bracket  330 . While a completely airtight seal may be impractical to achieve, the gasket  708  will restrict airflow through the gasket such that relatively little air is allowed to bypass the filter  304  by flowing around any cables inserted into the gasket  708 . Further, it is desirable that such an airflow restricting seal be maintained even when there are no cables connected and passing through the gasket  708 . It is further noted that an adhesive and/or tape material can be used to secure the gasket  708  within the void  704  for the support body  102 , if desired. For example, double-sided tape could be utilized to secure the gasket  708  within the void  704 . Other materials and techniques could also be utilized, as desired. 
     The material and shape for the support body  702  can be selected based upon a variety of factors, such as strength, rigidity, ease of fabrication, and/or other factors. For example, the support body  702  can be formed using injected molded plastic, if desired. The support body  702  can also be formed using a metal material that is shaped through a stamping process. Other materials and techniques could also be utilized, as desired, to form the support body  702 . Further, it is noted that the support body  702  can be implemented as a single piece or could be implemented as multiple pieces. Still further, it is noted that the opening  706  for the support body  702  can shaped to facilitate the insertion of cables, such as by being shaped to have a beveled opening  706 , as shown in  FIGS. 7A-B  and  8 A-B. 
     The material and structure for the gasket  708  can also be selected based upon a variety of factors, such as resilience, material memory, air seal quality, and/or other factors. For example, the gasket  708  can be formed using a flexible material that can be shaped and then secured within the void  704  for the support body  702 . In addition, the gasket  708  can be formed in multiple pieces that are inserted within the void  704 , or the gasket  708  can be formed as a single piece that is inserted into the void  704 . For example, a single foam piece could be folded and inserted into void  704  as the gasket  708 . Further, to provide for easier installation, a single die cut piece with a slit could also be inserted into void  704  for use as the gasket  708 . Further, as with the opening  706  for the support body  702 , the gasket  708  can be shaped to have an opening that facilitates the insertion of cables. Other variations and/or different structures could also be utilized, as desired, while still providing a gasket  708  that restricts lateral airflow through the cable support bracket  330 . 
     Materials that can be used for the gasket  708  include injection molded plastics, Quadrafoam 45 PPI foam (very soft), Quadrafoam 80 PPI foam (soft), Poron polyurethane foam (firm), Neoprene/EPDM/SBR blended foam (very firm), and/or other desired materials. It is noted that Quadrafoam materials are available from Universal Air Filter, that Poron polyurethane foam materials are available from Rogers Corporation, that Neoprene is available from DuPont, that EPDM is ethylene propylene diene monomer (M-class) rubber, and that SBR is Styrene Butadiene rubber. It is noted that for optical fiber cables and larger cables, such as CAT6 communication cables, Poron polyurethane foam has been found to provide a good seal while having a relatively little small permanent compression or set of the material after cables are removed. Other materials could also be utilized, as desired. 
     Further modifications and alternative embodiments will be apparent to those skilled in the art in view of this description. It will be recognized, therefore, that the present invention is not limited by these example arrangements. Accordingly, this description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the manner of carrying out the invention. It is to be understood that the forms of the invention herein shown and described are to be taken as the example embodiments. Various changes may be made in the implementations and architectures described herein. For example, equivalent elements may be substituted for those illustrated and described herein, and certain features of the embodiments may be utilized independently of the use of other features, as would be apparent to one skilled in the art after having the benefit of this description.