Patent Publication Number: US-2023154253-A1

Title: Detection of network issues and health reporting to ground-based stakeholders

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims benefit of Indian Patent Application Serial No. 202111051926 filed Nov. 12, 2021; the entire contents of the aforementioned patent application is incorporated herein by reference as if set forth in its entirety. 
     BACKGROUND 
     Aircraft operation generally includes the operation of multiple systems that communicate through different communication links with ground communication systems. These communication links include VHF, HF, satellite communication, and other communication links. On some aircraft, a communication management unit (CMU) has access to various statuses of the different communication links. The CMU can monitor the number of queued messages transmitted across the communication links and infer network issues. Examples of network issues may include channel utilization, received signal strength, message delivery issues, and latency issues measured from received acknowledgments (or analyzing timestamps of messages) from the ground systems. 
     SUMMARY 
     Systems and methods for detection of network issues and health reporting to ground-based stakeholders are described herein. In exemplary embodiments, a system includes a plurality of aircraft, wherein an aircraft in the plurality of aircraft communicates through one or more communication links. The aircraft includes one or more processors that compile network event information related to degraded communication link events. Further, the aircraft includes one or more memory units that store a degraded link event report and a configuration database, wherein the degraded link event report stores the compiled network event information related to the degraded communication link events as directed by information in the configuration database. The system additionally includes a network issue detector in communication with the plurality of aircraft, wherein the network issue detector receives degraded link event reports from the plurality of aircraft, wherein the network issue detector includes one or more network issue detector processors that identify systemic degraded data link network problems with the one or more communication links based on context identified in the degraded link event reports. 
    
    
     
       DRAWINGS 
       Understanding that the drawings depict only exemplary embodiments, the drawings are not, therefore, to be considered limiting in scope. This specification describes exemplary embodiments with additional specificity and detail through the use of the accompanying drawings, in which: 
         FIG.  1    is a drawing illustrating multiple aircraft in communication with multiple ground stations according to an aspect of the present disclosure; 
         FIG.  2    is a block diagram illustrating a system for facilitating communications between an aircraft and a communications network across multiple communication links according to an aspect of the present disclosure; 
         FIG.  3    is a flow diagram of a method for creating and transmitting degraded link event reports according to an aspect of the present disclosure; 
         FIG.  4    is a flow diagram of a method for processing degraded link event reports from multiple aircraft according to an aspect of the present disclosure; and 
         FIG.  5    is a flow diagram of a method for identifying systemic problems for communication links between multiple aircraft and a destination receiver according to an aspect of the present disclosure. 
     
    
    
     Per common practice, the various features described herein are not drawn to scale but are drawn to emphasize specific features relevant to the exemplary embodiments. 
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings that form a part hereof, and in which is shown, by way of illustration, specific illustrative embodiments. However, it is to be understood that other embodiments may be utilized, and that logical, mechanical, and electrical changes may be made. Furthermore, the method(s) presented in the drawings and the specification is not to be construed as limiting the order in which the individual steps may be performed. The following detailed description is, therefore, not to be taken in a limiting sense. 
     The present disclosure describes systems and methods for detecting network issues (past, present, and predicting future issues) in air-ground data communication links and for providing health reports for the communication links to ground-based stakeholders so that the ground-based stakeholders are aware of the issues to identify potential actions that can resolve the issues. In particular, processors on multiple aircraft gather health information for one or more communication links. As used in the present disclosure, health information refers to quantitative and qualitative information associated with the operational health of a communication link. Also, the health information may include information that represents the context around communications using the communication links. The context around a communication may include the communication itself, the location of the transmitter and/or receiver of the communication, the time of the communication, information regarding other related communications, operational status of the transmitter and receiver, type of communication, or other information potentially related to the communication. Information may relate to the communication if the information represents the operation of a system, an environmental factor, or other aspect that potentially affects transmissions through a communication link. 
     As described herein, a processor that gathers data link network health information operates on an aircraft. For example, the processor may be a communications management unit (CMU), a radio, or other processor associated with a system or systems on an aircraft. The processor communicates messages through a communication network with one or more destination receivers. The one or more destination receivers are in similar communication with multiple aircraft. Also, the destination receivers may be in communication with a network issue detector. The phrase “communication network” generally refers to a communication system that facilitates the transmission of information from an aircraft to a destination receiver and may consist of ground-based or orbital-based communication systems. For example, the communication networks may include ground communication systems, satellites that relay messages between aircraft and ground communication systems, and other aircraft that relay messages to ground communication systems. Further, a ground-based stakeholder may control or receive messages through the communication networks. For example, service providers connect to the ground communication systems and provide messages to the ground-based stakeholders. The ground-based stakeholders may include an original equipment manufacturer (OEM), an avionics manufacturer, airlines, the service providers, air traffic controllers, a government entity, or other party interested in receiving aircraft communications and/or the health of the communication links used for transmitting the communications. 
     During operation, a processor on an aircraft functions as part of an issue reporting system. The issue reporting system may be a CMU or other systems on the aircraft that can monitor multiple parameters regarding the status of the communication links between the aircraft and the destination receivers. When the issue reporting system is a CMU, the CMU may execute a communication management function (CMF) on an integrated platform along with other functions for monitoring the various parameters. For example, the monitored parameters may include status designations for the communication links, navigation parameters, identification for other connected communication systems, among other parameters that could provide information regarding the health of a prospective communication link, like contextual information (location, altitude, aircraft identification, etc.). In some embodiments, the issue reporting system may monitor health parameters indicative of the health status of the communication link to identify network events. When the health parameters indicate that the communication link has degraded or another type of network event of interest has occurred, the processor stores the network event information in a degraded link event report for transmission to a network issue detector through one of the available communication links. The network event information stored degraded link event report includes an indication of the degraded link event, a compilation of parameters monitored by the processor, and other contextual information from the perspective of an aircraft related to the communication link experiencing the degraded communications link event. 
     The network issue detector receives multiple degraded link event reports from multiple aircraft. As used herein, the network issue detector may refer to a system that analyzes the multiple degraded link event reports to identify systemic problems with communications between aircraft and the destination receivers. The network issue detector may be part of a destination receiver, a system controlled by a ground-based stakeholder, or a system located between one or more destination receivers and a ground-based stakeholder. The network issue detector analyzes the multiple degraded link event reports to identify systemic problems with a particular communication link. 
       FIG.  1    is a diagram illustrating multiple aircraft  101 - 1 - 101 - 2  in communication with multiple ground stations  111 - 1 - 111 - 3 . As used herein, the aircraft  101 - 1 - 101 - 2  are referred to generally and collectively as aircraft  101 . Similarly, the ground stations  111 - 1 - 111 - 3  are referred to generally and collectively as ground stations  111 . The aircraft  101  communicates with the ground stations  111  through various communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . As described herein, the aircraft  101  refers to an airborne vehicle, such that the aircraft  101  may be an airplane, helicopter, rocket, drone, or other vehicles capable of air travel, whether manned or autonomous. The ground stations  111  functions as examples of destination receivers for communications from the aircraft  101  through the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . Accordingly, the terms “ground stations” and “destination receivers” are interchangeable. Further, the term “ground station” is exemplary in nature, as a destination receiver may not necessarily be located on the ground. Further, the destination receiver may be an end system that communicates with the aircraft  101  through the ground stations  111 . 
     In additional embodiments, the aircraft  101  may have multiple systems that communicate with the ground stations  111  through the various communication links. As described herein, the communication links include combinations of wireless radio communication links between the ground stations  111  and the aircraft  101 . For example, communication links may include combinations of VHF radios, HF radios, satellite communications (both traditional safety datalink and Broadband datalink), Gatelink (Wi-Fi and Cell) communications, LDACS, AeroMacs, cellular, and other aviation-specific and civilian communication links. 
     In some exemplary embodiments, the different aircraft  101  may communicate with the same ground station  111 . For example, the aircraft  101 - 1  may communicate with the ground station  111 - 2  through the communication link  109 , and the aircraft  101 - 2  may communicate with the ground station  111 - 2  through the communication link  107 . Alternatively, the aircraft  101  may communicate with different ground stations  111 . For example, the aircraft  101 - 1  may communicate with the ground station  111 - 1  through the communication link  113 , and the aircraft  101 - 2  may communicate with the ground station  111 - 2  through the communication link  107 . Moreover, the aircraft  101  may communicate with different ground stations as the aircraft  101  fly. For example, the aircraft  101 - 1  may communicate with the ground station  111 - 1  and the ground station  111 - 2  at the same time, at different flight phases, or at different locations of the aircraft  101 - 1  during flight. Further, the aircraft  101  may communicate with each other to relay messages to a particular ground station  111 . For example, the aircraft  101 - 2  may communicate with the aircraft  101 - 1  through the communication link  115 , where the aircraft  101 - 1  then relays the received communications to the ground station  111 - 1  through the communication link  113 . 
     In additional embodiments, the aircraft  101  may communicate with a ground station  111  using satellite communications. For example, the aircraft  101 - 2  may transmit messages to a satellite  119  through the communication link  117 . Upon receiving the transmitted messages, the satellite  119  may relay the messages to the ground station  111 - 3  through the communication link  121 . Further, a ground station  111  may function as a relay for communications from an aircraft  101 . For example, the aircraft  101 - 1  may communicate with the ground station  111 - 1  through the communication link  113 , where the ground station  111 - 1  then provides the messages to the ground station  111 - 2 . In summation, the aircraft  101  may communicate with the ground stations  111  through various combinations of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . Also, service providers  123  may facilitate communications through the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . As used herein, a service provider  123  refers to a third party that sends messages, receives messages, or both via the ground stations  111  and through the network issue detector  105 . For example, a service provider may function as a central router between the aircraft  101  and the network issue detector  105  via the ground stations  111 . 
     During communications between the aircraft  101  and the ground stations  111 , the aircraft  101  can lose transmissions or receptions through one or more of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . When communications are lost, the aircraft  101  may send a message to one or more of the ground stations  111  via the service provider  123  to a network, indicating that a link has been lost. Also, the aircraft  101  may indicate the ground station  111  associated with the lost communication. The aircraft  101  may send the message upon reestablishment of the link or through an alternate, available link. Also, the aircraft  101  may store information regarding the lost link or communication issue and transmit the information later (on the ground or after the occurrence of certain events that trigger transmission of the information) through an alternative link or upon reestablishment of the lost link. The message may indicate the type of event or transmit an indication of the event in a later message. The event indication may indicate that the link was lost, degraded, reestablished, or other types of communication events. Alternatively, the communications may become degraded through the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . In some instances of degraded communications, the ground stations  111  may receive broadcasts from the aircraft  101  but cannot transmit uplink messages. Additionally, some of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121  may be available but experience excessive utilization and/or noise such that the aircraft  101 , while able to receive messages, cannot consistently transmit messages to the ground stations  111  or the messages are transmitted simultaneously with other aircraft messages transmitted to the ground stations  111 . Frequently, the ground stations  111  and the aircraft  101  may lack the desired information for determining the cause of events such as the loss of communications, degraded link, or excessive utilization. 
     In some examples where ground stations  111  and the aircraft lack the desired information, the aircraft  101  may include computing systems that monitor various parameters regarding network communications while managing communications from the aircraft  101  through the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . For example, the computing system may be a communication management unit or other computing system that can monitor the communications to and from the aircraft  101 . In some aircraft, the monitoring computing systems may maintain a record of the various parameters related to the status of the network communications. The monitoring computing system may provide this information to other computer systems through one or more of the ground stations  111  other than the network issue detector  105 . The other computer system may then perform a retroactive analysis of the recorded parameters to examine the performance of the monitoring computing system and issues related to communications through one or more of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . However, performing a typical retroactive analysis on information from a single airplane frequently cannot comprehend the desired context surrounding undesired network events, making it challenging to identify and rectify issues with the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . Also, the typical acquisition of the data frequently depends upon the physical retrieval of the information from the aircraft. When the monitoring computer system has a limited storage capacity, critical data can often be overwritten. Further, when retrieving data, technicians or mechanics may access trace logs stored on the aircraft. Coordinating the availability of the technicians/mechanics with aircraft turnaround time constraints can make the ordinary physical retrieval of the information difficult to support for aircraft operators and other interested parties. 
     An example of typical problems with acquiring information related to communication events may include lacking context surrounding events that occur due to the nature of the network. For example, typical information acquisition may lack information about a ground station communicating with a moving and potentially banking aircraft. Other issues may arise and occur frequently at certain locations, at certain times, or according to some other common problem that affects multiple aircraft or is systemic. For example, issues may arise due to aircraft relationships to ground stations  111 , interference issues, congested network issues, objects in the way of transmission paths, and the like. Typical communications may lack contextual information that may help identify the systemic problems. 
     In certain embodiments, the aircraft  101  may include an issue reporting system to gather information related to the context surrounding communications. As used herein, the issue reporting system may be a computing system that monitors communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121  for network events and compiles the network event information into a degraded link event report. The issue reporting system then transmits degraded link event reports to a network issue detector  105  via one or more of the ground stations  111  and at least one service provider  123 . The issue reporting system may be a communications management unit or other computing system located on the aircraft  111 . Upon reception of a degraded link event report from the aircraft  101 , the network issue detector  105  may analyze the degraded link event reports. The network issue detector  105  may be located as part of a ground station  111 , on a computing system controlled by a service provider, a computing system controlled by a ground-based stakeholder, or on a stand-alone computing system accessible by interested parties. 
     In some embodiments, the issue reporting system automatically sends the degraded link event reports to the network issue detector  105 , or the issue reporting system sends the degraded link event reports in response to a request from the network issue detector  105 . When the issue reporting system automatically sends the degraded link event report to the network issue detector  105 , the monitoring computing system may automatically send the degraded link event report after the passage of a specific time period, upon experiencing a communication triggering event, or after experiencing a report triggering event. Examples of communication triggering events may include the loss of communications, degradation of communications below a measurable threshold, the resumption of communications through one of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 , or other type of triggering events. Examples of report triggering events may include the end of a flight, the beginning of a flight, the collection of a defined number of events, the collection of a defined amount of data, a connection to a particular communication link associated with the network issue detector  105 , or other events that can direct the issue reporting system to provide the degraded link event report to the network issue detector  105 . 
     In some embodiments, when the issue reporting system experiences the loss of communications through one of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 , the issue reporting system may send the degraded link event report through a different communication link. For example, if the aircraft  101 - 1  is communicating through the communication link  109  and experiences degraded communications through the communication link  109 , the issue reporting system on the aircraft  101 - 1  may transmit the degraded link event report through one of the other available communication links  107 ,  113 ,  115 ,  117 , and  121  to provide the degraded link event report to the network issue detector  105 . 
     Upon receiving degraded link event reports from multiple aircraft, the network issue detector  105 , controlled by an interested stakeholder, may analyze the information in the degraded link event reports to identify systemic problems experienced by one or more of the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121 . As referred to herein, a systemic problem refers to a problem that affects a communication link between an aircraft  101  and a ground station  111 . For example, systemic problems may be associated with one or more of the following: a geographic location, altitude, phase of flight, time of day, communication equipment used, air traffic conditions, service provider, link network congestion, weather conditions, aircraft type, operator, or other factors that might affect transmission between the aircraft  101  and the ground stations  111 . Once a ground-based stakeholder identifies a systemic problem, the ground-based stakeholder can use the contextual information to investigate, characterize, and/or rectify the systemic problem. 
       FIG.  2    is a block diagram of a system  200  that can identify systemic problems in communicating over communication links. As illustrated, the system  200  includes an aircraft  201  and a network issue detector  205 . The aircraft  201  communicates with the network issue detector  205  through the communication links 209-1-209-3 (the communication links 209-1-209-3 are referred to herein either collectively or generally as communication link(s)  209 ). The communication links  209  may function similarly to the communication links  107 ,  109 ,  113 ,  115 ,  117 , and  121  described above in  FIG.  1   . Additionally, the aircraft  201  may function substantially as described above concerning the aircraft  101  in  FIG.  1   , and the network issue detector  205  may function substantially as described above concerning the network issue detector  105 . 
     In some embodiments, the aircraft  201  may communicate through the communication links  209  by emitting a signal through associated link transceivers 223-1-223-3. Similarly, the network issue detector  205  may communicate through the communication links  209  by providing communications to a service provider or providing the communications to a ground station transceiver  225  for transmission through an associated ground station transceivers 225-1-225-3. The individual link transceivers  223  and ground station transceivers  225  may be associated with different communication links  209 . In some implementations, when the ground station transceivers  225  are coupled to service providers (like the service provider  123 ), where the service providers link to operation centers, ATC centers, and, in embodiments described herein, a network issue detector  205  (which may be part of an operation center, ATC center, or other system in communication with the service provider. 
     In further embodiments, the aircraft  201  includes an issue reporting system  215  that monitors the communications through the links  209 . Additionally, the issue reporting system  215  may be part of a system that manages communications through the links  209 . For example, the issue reporting system  215  may be a communication management unit or other type of computing system that can manage or monitor communications through the links  209 . Additionally, in some implementations, the issue reporting system  215  is coupled to one or more additional aircraft systems  227 . The issue reporting system  215  may monitor communications through the communication links  209  from the one or more additional aircraft systems  227 . For example, the one or more additional aircraft systems  227  may include navigation systems, entertainment systems, sensing systems, pilot communication systems, among other systems that may operate on an aircraft  201 . 
     In some embodiments, the issue reporting system  215  includes one or more processors  217  and a memory unit  219 . The issue reporting system  215  uses the one or more processors  217  and the memory unit  219  to execute portions of the methods described in the present disclosure to compile and store network event information. For example, the one or more processors  217  and/or other computational devices used within the system  200  may be implemented using software, firmware, hardware, or an appropriate combination thereof. The one or more processors  217  and other computational devices may be supplemented by, or incorporated in, specially designed application-specific integrated circuits (ASICs) or field programmable gate arrays (FPGAs). The one or more processors  217  and other computational devices can also include or function with software programs, firmware, or other computer-readable instructions for carrying out various process tasks, calculations, and control functions used in the methods and systems described herein. 
     The methods described herein may be implemented or controlled by computer-executable instructions, such as program modules or components, executed by at least the one or more processors  217  or other computing devices. Generally, program modules include routines, programs, objects, data components, data structures, algorithms, and the like, which perform particular tasks or implement particular abstract data types. 
     Instructions for carrying out the various process tasks, calculations, and generation of other data used in the operation of the methods described herein may be implemented in software, firmware, or other computer-readable instructions. These instructions are typically stored on appropriate computer program products that include computer-readable media used to store computer-readable instructions or data structures. For example, the memory unit  219   may be computer-readable media that stores computer-readable instructions or data structures. Such a computer-readable medium may be available media that can be accessed by a general-purpose or special-purpose computer or processor, or any programmable logic device. 
     Suitable computer-readable storage media may include, for example, non-volatile memory devices including semi-conductor memory devices such as Random Access Memory (RAM), Read Only Memory (ROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory devices; magnetic disks such as internal hard disks or removable disks; optical storage devices such as compact discs (CDs), digital versatile discs (DVDs), Blu-ray discs; or any other media that can carry or store desired program code as computer-executable instructions or data structures. The memory unit  219  facilitates gathering information by the one or more processors  217  by storing information in a degraded link event report  220  and a configuration database  221 . 
     In certain embodiments, the one or more processors  217  monitors multiple parameters regarding network and link status for the compilation of network event information. The one or more processors  217  stores the network event information related to the monitored parameters in the degraded link event report  220 . Additionally, the one or more processors  217  creates the degraded link event report  220  and provides the degraded link event report  220  as directed by information stored in the configuration database  221 . The one or more processors  217  may provide the degraded link event report  220  to the network issue detector  205 . In some implementations, the one or more processors  217  provides the degraded link event report  220  to the network issue detector  205  automatically or upon request from the network issue detector  205 . 
     When automatically transmitting, the one or more processors  217  may periodically transmit a degraded link event report  220  to the network issue detector  205 . When the one or more onboard processors  217  periodically transmit a degraded link event report  220  to the network issue detector  205 , the configuration database  221  may define a frequency at which degraded link event reports  220  are transmitted to the network issue detector  205 . The network issue detector  205 , other computing systems, or configuration devices may communicate with the one or more processors  217  to change the transmission frequency stored in the configuration database  221 , either before, after, or during a flight. Alternatively, the one or more processors  217  automatically transmits degraded link event reports  220  to the network issue detector  205  in response to certain triggering events. Triggering events may be communication triggering events or be report triggering events. Communication triggering events may be related to the monitored communications and may include the loss of communications through one of the communication links  209 , the surpassing of a threshold by a particular monitored parameter, the resumption of communications through one of the communication links  209 , being at a particular geographic location, operating at a certain time of day, or other triggering event. In some implementations, report triggering events may be events related to information that describes the report or reporting process and may include the end of a flight, the beginning of a flight, particular phases of flight, the collection of a defined number of events, the collection of a defined amount of data, a connection to a particular communication link associated with the network issue detector  205 , or other events related to the degraded link event reports  220 . Other examples of report triggering events may include independent events from the report or reporting process and also independent from the communication triggering events. For example, report triggering events may also include landing at a certain airport, receiving an uplink request, the passage of a certain number of times, completing or beginning a certain number of flights, and the like. The configuration database  221  may store a list of different triggering events. Additionally, the network issue detector  205 , or other devices, may send information to the aircraft that defines a list of different triggering events through one of the communication links  209 . The issue reporting system  215  may store the received event defining information in the configuration database  221 . 
     In some embodiments, the configuration database  221  may also specify the device having the network issue detector  205 . For example, the configuration database  221  may specify that the network issue detector  205  is part of a computing system controlled by ground-based stakeholders. Also, the configuration database  221  may specify that the network issue detector  205  is part of a ground station or a stand-alone device. By specifying the device having the network issue detector  205 , the configuration database also specifies the recipients of transmissions of the degraded link event reports  220 . Additionally, the configuration database  221  may define parameters that interest other ground-based stakeholders. Accordingly, the one or more processors  217  may automatically transmit a degraded link event report  220  containing desired information to a particular ground-based stakeholder associated with the network issue detector  205  specified in the configuration database  221 . 
     In addition to acquiring the degraded link event reports  220  automatically from the aircraft  201 , the network issue detector  205  may acquire degraded link event reports  220  as desired by the network issue detector  205  or ground-based stakeholders that control the network issue detector  205 . For example, the one or more processors  217  may transmit the degraded link event reports  220  to the network issue detector  205  in response to receiving a request for the degraded link event reports  220  from the network issue detector  205 . 
     In addition to storing when and how to transmit the monitored parameters, the configuration database  221  may define when information is stored within the degraded link event report  220  and what information is stored within a degraded link event report  220 . For example, the configuration database  221  may define that the one or more processors  217  stores monitored parameters in the degraded link event report  220  periodically (or associated with the particular event), or the configuration database  221  defines triggering events for storing monitored parameters in the degraded link event report  220 . 
     When the configuration database  221  defines triggering events for storing parameters in the degraded link event report  220 , the triggering events may be similar to the communication triggering events described above concerning when the one or more processors  217  transmits a degraded link event report  220  to the network issue detector  205 . For example, the triggering events for storing parameters in the degraded link event report  220  may include the loss of communications through one of the communication links  209 , the surpassing of a threshold by a particular monitored parameter, the resumption of communications through one of the communication links  209 , being at a particular geographic location, operating at a certain time of day, or other triggering event. Additionally, the configuration database  221  may associate different sets of parameters with different triggering events. For example, if one triggering event occurs, the one or more processors  217  may identify the event in the degraded link event reports  220  and store parameters associated with the triggering event in the degraded link event report  220  as defined in the configuration database  221 . If a different triggering event occurs, the one or more processors  217  may store different parameters in the degraded link event report  220  that are associated with the different triggering events as defined in the configuration database  221 . Further, the degraded link event report  220  may store parameters at the time an event occurs, when a triggering event occurs, or both. 
     In certain embodiments, the one or more processors  217  may store data in the degraded link event report  220  that conveys information about the communications between the aircraft  201  and an end system or destination receiver (i.e., air traffic controller, airline operations, etc.) through one of the communication links. Also, the one or more processors may store data about the state of the aircraft  201  when communication events occur in the degraded link event report  220 . Additionally, the one or more processors  217  may store data about events experienced by the one or more processors  217 . Moreover, the one or more processors  217  may store data that implies events experienced by the one or more processors  217 . 
     In some embodiments, the one or more processors  217  stores statistical information related to loss of communications through one or more of the communication links  209 . For example, when the one or more processors  217  loses communications through a communication link  209 , the one or more processors  217  may increment a counter in the degraded link event report  220 . The counter indicates how many times communications have been lost through a communication link  209 . Also, the one or more processors  217  may store a duration for which communications were lost through a communication link  209 . Additionally, the one or more processors  217  may store the position and altitude at which communications were lost and the time that communications were lost through a communication link  209 . 
     In additional embodiments, the one or more processors  217  may store information related to lost communications in the degraded link event report  220 . For example, when the aircraft loses communications through a communication link  209  with a destination receiver on the ground, such as loss of communication with an air traffic control center, the one or more processors  217  may store the time and location of the aircraft  201  of the communications loss through the communication link  209 . Specifically, regarding aeronautical telecommunications network (ATN) air traffic control (ATC) centers, the one or more processors  217  may record the loss of communications with an ATN ATC center as a provider abort. 
     In further embodiments, the network issue detector  205  may be an air traffic controller, and the one or more processors  217  may store information related to communications with the air traffic controller in the degraded link event report  220 . For example, the one or more processors  217  may record whether the air traffic controller is a Future Air Navigation System (FANS) air traffic controller or an ATN ATC. Additionally, the one or more processors  217  may store information about failed logons in the degraded link event report  220 . The information about the failed logons may include whether the air traffic controller is a FANS or ATN ATC, the region of the ATC center, the time of the failed logon, and the location of where the failed login occurred. Additionally, the one or more processors  217  may store the current data authority and the next data authority in the degraded link event report  220 . 
     In some embodiments, the one or more processors  217  may store information concerning issues that arise in communications between a destination receiver and the aircraft  201 . For example, when the one or more processors  217  receive an incomplete or invalid uplink from a destination receiver, the one or more processors  217  may increment an incomplete uplink counter in the degraded link event report  220 . Similarly, when the one or more processors  217  receive a corrupted uplink from a destination receiver, the one or more processors  217  may increment a corrupted uplink counter in the degraded link event report  220 . Additionally, the one or more processors  217  may store information received through an uplink from a destination receiver. For example, the one or more processors  217  may expect to receive a series of packets in a specific sequence. For instance, the packets may include information identifying the number of a particular packet. At times, the one or more processors  217  may receive packets out of sequence. When the one or more processors  217  receive the out of sequence packets, the one or more processors  217  may store information in the degraded link event report  220  identifying the numbers of the out-of-sequence packets, and, also, the one or more processors  217  may store information in the degraded link event report  220  about the sequence of the out-of-order packets. 
     Additionally, the one or more processors  217  may store information about lost packets in the degraded link event report  220 . For example, when the one or more processors  217  determines that a packet was lost, the one or more processors  217  may increment a lost packet counter in the degraded link event report  220  for the particular communication link  209 . Additionally, as some systems may have multiple layers in a communication protocol stack, the degraded link event report  220  may include multiple lost packet counters, where each packet counter is associated with a different type of packet or layer. Further, the one or more processors  217  may maintain a lost packet identifier list in the degraded link event report  220 , where the lost packet identifier list contains a list of expected identifiers for expected packets that were not received by the one or more processors  217 . 
     In additional embodiments, the one or more processors  217  may store information related to the quality of the communication link  209 . For example, the one or more processors  217  may store information about message latency in the degraded link event report  220 . To acquire information about message latency, the one or more processors  217  may track the time between transmission of a downlink and the reception of an acknowledgment from a ground station or other ground system (like an ATC center or operations center). For example, the one or more processors  217  may store timestamp values for when a message is transmitted and received along with the current time. Moreover, the one or more processors  217  may store information related to the signal strength of the communication link  209  between the ground stations and the aircraft  201 . For example, the one or more processors  217  may periodically store the signal strength, or store measurements of signal strength in the degraded link event report  220  upon the occurrence of a triggering event. Additionally, the one or more processors  217  may store measurements of channel utilization in the degraded link event report  220  for a particular communication link  209 . Again, the one or more processors  217  may store the channel utilization measurements periodically or upon the occurrence of a triggering event. 
     In some embodiments, the one or more processors  217  may store information describing the physical relationship of the aircraft  201  (or communication equipment on the aircraft  201 ) to a ground station in the degraded link event report  220 . For example, the one or more processors  217  may store information describing the physical distance between a connected ground station and the aircraft  201  and the orientation (in-front, behind, underneath, off to the side, etc.) of the aircraft  201  in relation to the ground station in the degraded link event report  220 . Additionally, the one or more processors  217  may store information about the bank angle of the aircraft  201  in the degraded link event report  220 . For example, as the aircraft  201  turns or banks, portions of the body of the aircraft  201  may interfere with the line of sight between communication apparatus on the aircraft  201  and the ground station. Thus, either automatically or upon a triggering event, the one or more processors  217  may store the bank angle of the aircraft  201  in the degraded link event report  220 . Further, to help determine whether the body of the aircraft  201  interferes with a communication link  209 , the one or more processors  217  may also store information describing the location of antennas associated with the communication links  209  in the degraded link event report  220 . Moreover, the one or more processors  217  may store information related to the velocity of the aircraft  201  in relation to a ground station in the degraded link event report  220 . For example, the speed of the aircraft  201  relative to the ground station may lead to degradation of communications through the communication links  209  because of Doppler effects. 
     In further embodiments, the one or more processors  217  may increment a retransmission counter when the one or more processors  217  retransmits a message to a destination receiver through a ground station. For example, the one or more processors  217  may transmit a message to a destination receiver through a ground station. If the one or more processors  217  fails to receive an acknowledgment from the destination receiver for the transmitted message, the one or more processors  217  may retransmit the message. The one or more processors  217  may increment the retransmission counter when the message is retransmitted to the destination receiver. In some implementations, the degraded link event report  220  may include a separate retransmission counter for each of the retransmitted messages along with an identifier of the retransmitted messages. Also, the degraded link event report  220  may include a total retransmission counter that is incremented when any message is retransmitted, a counter for the number of messages that were retransmitted a maximum number of times, along with a counter for the number of timers that expired waiting for the reception of acknowledgments from destination receivers. In additional implementations, the one or more processors  217  may transmit the degraded link event report  220  to the network issue detector  205  as part of retransmitting the message to a destination receiver (or other network entity in a communication network. 
     In some embodiments, the degraded link event report  220  may include information about the operational health of equipment used to facilitate communications through the communication links  209 . For example, the one or more processors  217  may monitor the health of a VHF radio or other communication radio. The one or more processors  217  may record whether a communication link  209  that has failed did so because the VHF radio experienced a system reset, a fault, or a failure on the aircraft. Additionally, the one or more processors  217  may also store information regarding the health of a CMU performing management tasks along with executing the functions of the issue reporting system  215 . For example, when the issue reporting system  215  is executed by a CMU, the one or more processors  217  may store information about the health of the CMU. The health of the CMU may include CMU resets, faults, failures, or other events directly or indirectly related to the health of the CMU. 
     In some situations, the communication link  209  between the aircraft  201  and a destination receiver may be handed off between ground station transceivers  225  and different communication links (like VHF and SATCOM). For example, when the aircraft  201  moves from traveling over land to traveling over an ocean, one of the ground station transceivers  225  may handoff communications to another ground station transceiver  225 . Also, the different ground station transceivers  225  may be associated with different regions, and the communications may be passed between different ground station transceivers  225  as the aircraft  201  travels from one region to another. Additionally, the different ground station transceivers  225  may be associated with different types of communication links  209  (like SATCOM, VHF, HF, and the like), and the communications may be passed between different ground station transceivers  225  or communication link types when the communications are passed to other types of communication links  209 . When communications are transferred between different communication links  209 , individual link transceivers  223 , or different ground station transceivers  225 , the one or more processors  217  may store information related to these handoffs in the degraded link event report  220 . 
     In certain embodiments, the information related to the handoffs may include identifiers for the service providers associated with the handoff and identifiers for the ground antennas (or satellites) associated with the handoff. Additionally, the information may describe the location (altitude, attitude, latitude, longitude, etc.) where the handoff occurred, the frequency with which the handoff occurred, and the duration of the handoff. For example, when collecting information about a handoff, the one or more processors  217  may initiate a timer for the handoff and record the time when the handoff completes. In a further example, when the handoff is between a VHF communication link  209  and a SATCOM communication link  209  or vice versa, the one or more processors  217  may initiate a timer. If the timer expires, the one or more processors  217  may record the expired timer (such as Routing Airborne Timer 1 (RAT1) expiration) in the degraded link event report  220 . 
     In additional embodiments, the one or more processors  217  may store statistics information for the different communication links  209  between the aircraft  201  and destination receivers through the ground stations in the degraded link event report  220 . For example, the one or more processors  217  may store a connection table, such as a peer entity connection table, which includes information about the connection status. In particular, the connection table may store information about the connection status of VHF radios and ground stations associated with a destination receiver. Additionally, the one or more processors  217  may increment a counter in the degraded link event report  220  when a message is sent or received between aircraft  201  and a destination receiver. For example, the degraded link event report  220  may have a sent message counter and a received message counter, where the one or more processors  217  increments the sent message counter when a message is sent from the aircraft  201  to destination receiver, and the one or more processors  217  increments the received message counter when a message from the destination receiver is received by the aircraft  201 . Further, the one or more processors  217  may store the length of connections through a particular communication link  209  and the frequency with which communications have switched between different communication links  209 . 
     As described above, the one or more processors  217  transmits the degraded link event report  220  to the network issue detector  205  as requested by the network issue detector  205  or upon the occurrence of a monitored event. The network issue detector  205  communicates with multiple aircraft  201  and receives the separate degraded link event reports  220  from the various aircraft  201 . As illustrated, the network issue detector  205  may also include one or more network issue detector processors  229 . The network issue detector processors  229  may control and monitor communications through the communication links  209  with various aircraft  201 . Additionally, the network issue detector processors  229  store received degraded link event report  220  from the aircraft  201  as reports  233  on a memory unit  231 . The network issue detector processors  229  and the memory unit  231  may function in a similar manner as described above concerning the one or more processors  217  and the memory unit  219 . 
     In certain embodiments, upon receiving multiple degraded link event reports  220  from multiple aircraft  201 , the network issue detector processors  229  may analyze the data in the reports  233  to identify systemic degraded data link network problems with the communication links  209 . As used herein, a systemic degraded data link network problem may refer to a network problem that negatively impacts systems that facilitate communications between aircraft  201  and destination receivers through the ground stations and communication links  209 . Further, a degraded data link network problem may be a network problem that affects communications between multiple aircraft  201  and one or more destination receivers. Degraded data link network problems may be common with the communication software or hardware on the aircraft  201 . Additionally, degraded data link network problems may include hardware or software problems with the equipment that relays messages between aircraft  201  and associated destination receivers. Further, the degraded data link network problems may include problems associated with a particular geographic location. Also, degraded data link network problems may be associated with communication hardware or software at the destination receiver. 
     In certain embodiments, the network issue detector  205  analyzes the compiled network information in the reports  233  to identify the context around degradations of communications through the communication links  209 . As used herein, the context around a degradation refers to information representing the state of the aircraft  201 , communication facilities that support the communication links  209 , and the destination receiver when communication degradations occur. Using reports  233  from multiple aircraft  201 , the network issue detector processors  229  may identify context related to directly measurable communication events (events that generate data that are directly related to communications, such as failure of communication facilities) and implied communication events (events that generate data that are indirectly related to communications, such as the location of the aircraft). The network issue detector  205  can use the identified context around the failures to identify systemic degraded data link network problems for the communication links  209  that have occurred in the past, are presently affecting the communication links  209 , or that may affect the communication links  209  in the future. 
     In some embodiments, the network issue detector  205  identifies systemic problems from the data stored in the reports  233 . In particular, the network issue detector  205  may analyze the reports  233  for past degraded links experienced, problems currently being experienced, and problems that could potentially be experienced by at least one aircraft  201  in communication with the network issue detector  205 . When identifying past, present, or potential future problems, the network issue detector  205  may review the reports  233  for indications of degraded link data. The indications of degraded link data may include data transmitted in a degraded link event report  220  that are outside a desired operating range. After identifying indications of degraded link data, the network issue detector  205  may further analyze the data from multiple aircraft  201  to determine whether the identified indication is specific to one aircraft  201  or multiple aircraft  201 . If the indication applies to multiple aircraft, the network issue detector  205  may determine that there is a systemic problem. When a systemic problem has been identified, the network issue detector  205  may also analyze the reports  233  to identify the cause of the systemic problem. In an additional implementation, the network issue detector processors  229  may compare the recently acquired data against previously acquired data in the reports associated with systemic problems. For example, the network issue detector processors  229  may compare the recently acquired data by looking for similar data in the recently acquired data or by implementing machine learning algorithms trained by the previously acquired data. 
     Referring to the components described in  FIG.  2   ,  FIG.  3    is a flow diagram of a method  300  for creating degraded link event reports by an issue reporting system  215  and transmitting the degraded link event reports to a network issue detector  205 . The method  300  proceeds at  301 , where communication links  209  are monitored. For example, the issue reporting system  215  may monitor the operation of the communications from the aircraft  201  through one or more communication links  209 . The method  300  then proceeds at  303 , where information related to degraded link events is stored in a degraded link event report  220  as directed by information in a configuration database  221 . 
     In some embodiments, when the information is stored in the degraded link event report  220 , the method  300  proceeds to determine whether to transmit the degraded link event report  220  to a network issue detector  205 . To determine whether to transmit the degraded link event report  220 , the method  300  may proceed to  305 , where the issue reporting system  215  determines whether a request for the degraded link event report  220  has been received from the network issue detector  205 . If a request has been received, the method  300  proceeds to  313 , where the degraded link event report  220  is transmitted to the network issue detector  205 . If a request has not been received, the method  300  may return to  301  for continued monitoring of the communication links  209 . 
     In further embodiments, the method  300  may determine whether to automatically transmit the degraded link event report  220  to the network issue detector  205 . To determine whether to automatically transmit the degraded link event report  220 , the method  300  may proceed to  307 , where the issue reporting system  215  determines whether a time period has expired. If the time period has expired, the method  300  proceed to  313 , where the degraded link event report  220  is transmitted to the network issue detector  205 . If the time period has not expired, the method  300  may proceed to  309 , where the issue reporting system  215  determines whether a communication triggering event has occurred. If a communication triggering event has occurred, the method  300  proceeds to  313 , where the degraded link event report  220  is transmitted to the network issue detector  205 . If a communication triggering event has not occurred, the method  300  proceeds to  311 , where the issue reporting system  215  determines whether a report triggering event has occurred. If a report triggering event has occurred, the method  300  proceeds to  313 , where the degraded link event report  220  is transmitted to the network issue detector  205 . If a report triggering event has not occurred, the method  300  proceeds to  301  for continued monitoring of the communication links  209 . While the method  300  shows the detection of time period expiration, communication triggering events, and report triggering events being performed serially, the method  300  may also perform the detection of time period expiration, communication triggering events, and report triggering events in parallel. 
     Referring to the components described in  FIG.  2   ,  FIG.  4    is a flow diagram of a method  400  for processing degraded link event reports  233  received from multiple aircraft  201  by a network issue detector  205 . The method  400  proceeds at  401 , where the network issue detector  205  receives degraded link event reports from multiple aircraft. Also, the network issue detector  205  may receive multiple degraded link event reports from the same aircraft. For example, the network issue detector  205  may receive multiple degraded link event reports from the multiple aircraft  201  through one or more of the communication links  209 . Further, the method  400  proceeds at  403 , where the network issue detector  205  stores the degraded link event reports on a memory device. For instance, the network issue detector  205  may store the received degraded link event reports in the reports  233  on the memory unit  231 . 
     In certain embodiments, the method  400  may proceed at  405 , where the network issue detector  205  identifies a degraded link event in at least one degraded link event report based on an indication of degraded link data. For example, the network issue detector processor  233  may analyze the data stored in the reports  233  to identify degraded link events. Degraded link data is data that indicates loss of communication through a communication link or that measurable parameters associated with a communication link were outside of a desired operational range. When the network issue detector processor  229  identifies a degraded link event, the method  400  may proceed at  407 , where the network issue detector  205  determines if the degraded link event is recorded in multiple reports. For example, the network issue detector processor  229  may analyze the multiple reports  233  for similar degraded link events. If the network issue detector processor  229  does not find the degraded link event recorded in more than one degraded link event report, then the method  400  returns to  401 , where the network issue detector  205  continues to receive degraded link event reports from multiple aircraft. Alternatively, the network issue detector  205  may identify the degraded link event as a specific problem for the aircraft that provided the degraded link event report. 
     In exemplary embodiments, when the degraded link event is recorded in multiple reports, the method  400  may proceed at  409 , where the network issue detector  205  identifies contextual information related to the degraded link event in the multiple degraded link event reports. For example, the network issue detector processor  229  may analyze the degraded link event reports  233  for information related to the context of the degraded link event. Further, the method  400  may proceed at  411 , where the network issue detector  205  determines the cause of the degraded link event or a systemic issue with a communication link  209  based on the identified contextual information. Additionally, the method  400  may proceed at  413 , where the network issue detector  205  identifies the cause as a systemic problem with a communication link associated with the degraded link event. When a systemic problem is identified, a ground-based stakeholder can use the information to rectify the systemic problem or deal with the systemic problem as desired. 
       FIG.  5    is a flow diagram of a method  500  for identifying systemic problems for communication links between aircraft and a destination receiver, such as a ground station. The method  500  proceeds at  501 , where an aircraft and a destination receiver communicate through one or more communication links. Further, the method  500  proceeds at  503 , where a degraded communication link event is identified. Moreover, the method  500  proceeds at  505 , where network event information related to the degraded communication link event is compiled in a degraded link event report. 
     In additional embodiments, the method  500  proceeds at  507 , where the degraded link event report is transmitted to a network issue detector. Additionally, the method  500  proceeds at  509 , where multiple degraded link event reports are analyzed from multiple aircraft by the network issue detector. Also, the method  500  proceeds at  511 , where systemic degraded data link network problems with the one or more communication links are identified based on context identified in the multiple degraded link event reports. 
     Example Embodiments 
     Example 1 includes a system comprising: a network issue detector configured to receive degraded link event reports from the multiple aircraft through one or more data communication links, wherein each of the multiple aircraft comprises one or more aircraft processors that compile network event information related to degraded communication link events in a degraded link event report, wherein the degraded link event report describes context surrounding the degraded communication link events from a perspective of an aircraft in the multiple aircraft, wherein the network issue detector comprises one or more network issue detector processors that identify systemic degraded data link network problems with the one or more data communication links for time and location based on the context identified in the degraded link event reports. 
     Example 2 includes the system of Example 1, wherein the one or more aircraft processors are part of a communication management unit. 
     Example 3 includes the system of any of Examples 1-2, wherein the network issue detector receives the degraded link event report from the aircraft in response to sending a request for the degraded link event report from the network issue detector. 
     Example 4 includes the system of any of Examples 1-3, wherein the network issue detector receives the degraded link event report from the aircraft that was automatically sent by the aircraft. 
     Example 5 includes the system of Example 4, wherein the aircraft automatically sends the degraded link event report to the network issue detector after at least one of: expiration of a period; occurrence of a communication triggering event; and occurrence of a report triggering event. 
     Example 6 includes the system of Example 5, wherein the communication triggering event includes at least one of: communication loss through the one or more data communication links; communication degradation through the one or more data communication links below a measurable threshold; and communication resumption through the one or more data communication links after the communication loss. 
     Example 7 includes the system of any of Examples 1-6, wherein the network issue detector sends instructions to the aircraft that direct compilation of the network event information by the one or more aircraft processors according to the instructions stored in a configuration database stored on the aircraft. 
     Example 8 includes the system of Example 7, wherein the aircraft stores the instructions in the configuration database. 
     Example 9 includes the system of any of Examples 7-8, wherein the instructions specify the network issue detector as a recipient for a transmission of the degraded link event report. 
     Example 10 includes the system of any of Examples 1-9, wherein the degraded link event report keeps at least one of: statistical information related to the communications through the one or more data communication links; identified issues that arise during the communications through the one or more data communication links; information related to quality of the communications through the one or more data communication links; data describing a physical relationship of the aircraft in the multiple aircraft to a destination communicating with the aircraft through the one or more data communication links; health information for equipment on the aircraft; and handoff information. 
     Example 11. A method comprising: communicating through one or more communication links between an aircraft and a destination receiver; identifying a degraded communication link event; compiling network event information related to the degraded communication link event in a degraded link event report; transmitting the degraded link event report to a network issue detector; analyzing multiple degraded link event reports from multiple aircraft by the network issue detector; and identifying systemic degraded data link network problems with the one or more communication links based on context identified in the multiple degraded link event reports. 
     Example 12 includes the method of Example 11, wherein transmitting the degraded link event report to the network issue detector comprises transmitting the degraded link event report in response to a request for the degraded link event report from the network issue detector. 
     Example 13 includes the method of any of Examples 11-12, wherein transmitting the degraded link event report to the network issue detector comprises automatically transmitting the degraded link event report to the network issue detector. 
     Example 14 includes the method of Example 13, wherein automatically transmitting the degraded link event report to the network issue detector comprises transmitting the degraded link event report to the network issue detector after at least one of: expiration of a period; occurrence of a communication triggering event; and occurrence of a report triggering event. 
     Example 15 includes the method of Example 14, wherein the communication triggering event includes at least one of: communication loss through the one or more communication links; communication degradation through the one or more communication links below a measurable threshold; and resumption of communications through the one or more communication links. 
     Example 16 includes the method of any of Examples 11-15, wherein compiling the network event information related to the degraded communication link event further comprises compiling the network event information as specified by instructions in a configuration database stored on the aircraft. 
     Example 17 includes the method of Example 16, further comprising configuring the instructions stored in the configuration database as directed by the network issue detector. 
     Example 18 includes the method of any of Examples 16-17, wherein the configuration database specifies the network issue detector as a recipient for a transmission of the degraded link event report. 
     Example 19 includes a system comprising: a plurality of aircraft, wherein an aircraft in the plurality of aircraft communicates through one or more communication links, the aircraft comprising: one or more processors that compile network event information related to degraded communication link events; and one or more memory units that store a degraded link event report and a configuration database, wherein the degraded link event report stores the compiled network event information related to the degraded communication link events as directed by information in the configuration database; and a network issue detector in communication with the plurality of aircraft, wherein the network issue detector receives degraded link event reports from the plurality of aircraft, wherein the network issue detector comprises one or more network issue detector processors that identify systemic degraded data link network problems with the one or more communication links based on context identified in the degraded link event reports. 
     Example 20 includes the system of Example 19, wherein the aircraft sends a respective degraded link event report to the network issue detector in response to a request for the degraded link event report from the network issue detector. 
     Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated to achieve the same purpose, may be substituted for the specific embodiments shown. Therefore, it is manifestly intended that this invention be limited only by the claims and the equivalents thereof.