Patent Publication Number: US-9848433-B2

Title: Hybrid air-to-ground and satellite system traffic management

Description:
BACKGROUND 
     Field of the Invention 
     This disclosure relates to communications technology and more particularly to providing communications services to users on an aircraft. 
     Description of the Related Art 
     A typical communications system provides users with in-flight wide area network communications services, and, in some cases, also provides users on an aircraft with in-flight local area network communications services (e.g., a wireless local-area network (WLAN) based on the Institute of Electrical and Electronics Engineers&#39; 802.11 standards). Although terrestrial equipment may provide wide-area network communications services to user equipment while the aircraft is on the ground and aircraft equipment may provide wide-area network communications services via a satellite communications system to a user while in flight, satellite network capacity is limited and expensive and ground access to terrestrial WLAN networks is available for only a small portion of time that a user spends on the aircraft. Accordingly, improved techniques for providing communications services to users on an aircraft are desired. 
     SUMMARY OF EMBODIMENTS OF THE INVENTION 
     A technique for providing users with in-flight connectivity includes a method for operating a communications system on an aircraft comprising allocating to a communications session between equipment on the aircraft and other equipment, a first bandwidth allocation of a selected communications system selected from the group consisting of a satellite communications system and an air-to-ground communications system. The allocating is based on a latency tolerance of the communications session and a prioritization level of the communications session. The method includes communicating signals of the communications session using the first bandwidth allocation of the selected communications system. The air-to-ground communications system may be selected until the air-to-ground communications system bandwidth is approximately a threshold air-to-ground bandwidth allocation for the aircraft. The method may include allocating an aircraft-area bandwidth to the communications session based on at least one of capability of the equipment on the aircraft and subscription information associated with the equipment on the aircraft. The method may include communicating the signals of the communications session further using the aircraft-area bandwidth. The prioritization level may be selected from a plurality of prioritization levels based on a type of the equipment on the aircraft. The plurality of prioritization levels may include a prioritization level of aircraft passenger user equipment, a prioritization level of avionics equipment, a prioritization level of an in-flight entertainment system, and a prioritization level of aircraft personnel communications equipment. The selected communications system may be the satellite communications system in response to the communications session being tolerant of a high latency and the selected communications system is the air-to-ground communications system in response to the communications session being intolerant of the high latency. The communications session may be a transport layer session of an open systems interconnection model communications system. The method may include allocating aircraft-area bandwidth to the communications session according to the prioritization level of the equipment on the aircraft. The prioritization level may be selected from a plurality of prioritization levels based on a type of the equipment on the aircraft, the plurality of prioritization levels including a prioritization level of aircraft passenger user equipment, a prioritization level of avionics equipment, a prioritization level of an in-flight entertainment system, and a prioritization level of aircraft personnel communications equipment. The method may include communicating signals of the communications session using the aircraft-area bandwidth allocation. The selected communications system may be the satellite communications system and the method may include handing off the communications session from the satellite communications system to the air-to-ground communications system. The method may include communicating the signals of the communications session using a second bandwidth allocation of the air-to-ground communications system. The second bandwidth may be allocated based on the latency tolerance of the communications session and the prioritization level of the communications session. The method may include handing off the communications session from the air-to-ground communications system to the satellite communications system. The method may include communicating the signals of the communications session using a third bandwidth allocation of the satellite communications system, the third bandwidth being allocated based on the latency tolerance of the communications session and the prioritization level of the communications session. 
     The method may include handing off the communications session from the satellite communications system to a terrestrial communications system. The method may include communicating the signals of the communications session using a fourth bandwidth allocation of the terrestrial communications system. The fourth bandwidth is allocated based on the prioritization level of the communications session. The method may include allocating satellite communications system bandwidth to the aircraft according to aircraft altitude. The method may include allocating air-to-ground communications system bandwidth to the aircraft according to aircraft altitude. The first bandwidth may be allocated based on the satellite communications system bandwidth allocated to the aircraft and the air-to-ground communications system bandwidth allocated to the aircraft. 
     In at least one embodiment of the invention, an apparatus for communications on an aircraft includes a first modem, a second modem, and a controller configured to allocate to a communications session between equipment on the aircraft and other equipment, a first bandwidth allocation of a selected communications system selected from the group consisting of a satellite communications system and an air-to-ground communications system. The first modem is configured to process signals communicated with a non-terrestrial relay point. The second modem is configured to process signals communicated with a terrestrial relay point. The allocating is based on a latency tolerance of the communications session and a prioritization level of the communications session, the controller communicating signals of the communications session with the first modem and the second modem according to the first bandwidth allocation. The apparatus may include a wireless local area access node configured to communicate with user equipment on the aircraft. The apparatus may include a small cell access node configured to communicate with user equipment on the aircraft. The controller may be further configured to allocate an aircraft-area bandwidth to the communications session based on at least one of capability of the equipment on the aircraft and subscription information associated with the equipment on the aircraft. The controller may be configured to communicate the signals of the communications session further using the aircraft-area bandwidth. The prioritization level may be selected from a plurality of prioritization levels based on a type of the equipment on the aircraft, the plurality of prioritization levels including a prioritization level of aircraft passenger user equipment, a prioritization level of avionics equipment, a prioritization level of an in-flight entertainment system, and a prioritization level of aircraft personnel communications equipment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure may be better understood, and its numerous objects, features, and advantages made apparent to those skilled in the art by referencing the accompanying drawings. 
         FIG. 1  illustrates a functional diagram of an exemplary in-flight communications system. 
         FIG. 2  illustrates a functional block diagram of network elements of the in-flight communications network of  FIG. 1 . 
         FIG. 3  illustrates a functional block diagram of network architecture of an exemplary in-flight communications network. 
         FIG. 4  illustrates a functional block diagram of resources for communicating calls and texts using the exemplary in-flight communications network of  FIG. 3 . 
         FIG. 5  illustrates a functional block diagram of an exemplary in-flight communications network. 
         FIG. 6  illustrates a functional block diagram of an exemplary in-flight communications network configured for traffic classification based balancing. 
         FIG. 7  illustrates a functional block diagram of an exemplary in-flight communications network configured to partition traffic based on network layer information. 
         FIG. 8  illustrates a functional block diagram of an exemplary in-flight communications network configured to split traffic based on network layer information and bundle on an exemplary transmission control protocol (TCP) connection on one link. 
         FIG. 9  illustrates a functional block diagram of an exemplary aircraft communications system from  FIG. 5  configured to use multipath TCP on air-to-ground link. 
         FIG. 10  illustrates a functional block diagram of aircraft equipment architecture for the exemplary in-flight communications network of  FIG. 5 . 
         FIG. 11  illustrates a diagram of an exemplary in-flight communications network representation of a link budget based on aircraft altitude. 
         FIG. 12  illustrates an exemplary in-flight communications network implementing aircraft-specific resource allocation. 
         FIG. 13  illustrates exemplary information and control flows for radio resource management in an exemplary in-flight communications system. 
     
    
    
     The use of the same reference symbols in different drawings indicates similar or identical items. 
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , in-flight communications network  100  uses air-to-ground communications and satellite communications to provide in-flight wide area access to users on aircraft  102 . An exemplary air-to-ground system includes a terrestrial relay point (e.g., an up-tilted antenna coupled to an eNodeB, base transceiver station, or other communications system coupled to a network) that directly communicates with wireless handsets or other user equipment, scattered across a service area. When using satellite communications, aircraft  102  communicates with a non-terrestrial relay (e.g., satellite  104 ), which communicates signals to terrestrial network  110  via satellite band signal receiver  106  and associated equipment. Exemplary satellite band signals use a portion of the electromagnetic spectrum allocated to satellite communications, including signals operating in the Super High Frequency (SHF) band (e.g., 3 to 30 GHz), C band (e.g., 4 GHz to 8 GHz), G band (e.g., NATO G band of 4 GHz to 6 GHz, IEEE G band of 110 GHz to 300 GHz, or obsolete G band 140 MHz to 220 MHz), H Band (e.g., 6 GHz to 8 GHz), Ku band (e.g., 12 GHz to 18 GHz), Ka band (e.g., 26.5 GHz to 40 GHz), L band (e.g., 40 GHz to 60 GHz or 1 GHz to 2 GHz), X band (e.g., 7 GHz to 12 GHz), and F band (e.g., 3 GHz to 4 GHz), or other portions of the electromagnetic spectrum suitable for long-distance radio telecommunications. When using air-to-ground communications, aircraft  102  communicates with cell tower  108 , which communicates signals to terrestrial network  110 . Exemplary air-to-ground signals use sets of frequency ranges within the ultra high frequency band allocated for cellular phone use (e.g., 800 MHz). 
     Referring to  FIG. 2 , in at least one embodiment, in addition to the aircraft air-to-ground communications links and the satellite communications links  502 , the in-flight communications network includes in-cabin local area network (e.g., aircraft WiFi  504 ) equipment, a radio access network  506 , which is coupled to core network  526  and a back end system  532 , e.g., using antenna  508 , microwave antenna  514 , microwave terminal  520 , base station  522 , and terrestrial transport network  524 . Core network  526  includes one or more of Evolved Packet Core (EPC)  528  (e.g., the core network of the Long Term Evolution (LTE) system of the 3GPP core network architecture, also known as System Architecture Evolution (SAE) core, which is an All Internet Protocol Network (AIPN)), Internet Protocol (IP) Multimedia Subsystem (IMS) network  530 , or other suitable core network. Back-end system  532  provides policy, billing and support systems. The in-flight communications network includes one or more of the following services: advanced Mi-Fi puck, Internet, video, video calling, and voice/text (e.g. short message service (SMS) or voice calls to native applications or number). The in-flight communications network includes a wireless router that serves as a mobile WiFi hotspot, e.g., connects to core network  526  and provides Internet access for multiple devices on the aircraft. In addition, the in-flight communications network is compatible to various regional services (e.g., United States and European Union). 
     Referring to  FIG. 3 , exemplary in-flight communications network  300  uses an air-to-ground communications network separate from a satellite communications network and includes an evolved packet core network including mobility management entity  312 , serving gateway  314 , packet data network gateway  316 , and policy and charging rules function (PCRF)  318 . Mobility management entity  312  performs signaling and control functions to manage access to network connections by users on aircraft  302  and aircraft  304 , assignment of network resources to aircraft  302  and aircraft  304 , and mobility management functions, e.g., idle mode location tracking, paging, roaming, and handovers. Mobility management entity  312  controls all control plane functions related to subscriber and session management for air-to-ground service to users on aircraft  302  and aircraft  304 . In addition, mobility management entity  312  provides security operations including providing temporary identities for user terminals, interacting with home subscriber server  320  for authentication, and negotiation of ciphering and integrity protection algorithms. 
     As referred to herein, a session is an active communication of data over a network between two devices and may include a first data stream from a first device to the second device and a second data stream from the second device to the first device. It may be possible to have more than one session between two devices simultaneously. Mobility management entity  312  selects suitable serving and Packet Data Network (PDN) gateways, and selects legacy gateways for handover to other networks. Mobility management entity  312  manages a plurality (e.g., thousands) of eNodeB elements or evolved packet data gateway elements. Serving gateway  314  manages user plane mobility. Serving gateway  314  routes and forwards user data packets. Serving gateway  314  also behaves as a mobility anchor during inter-eNodeB handovers and as the anchor for mobility between LTE and other 3GPP technologies. Packet data network gateway  316  provides connectivity from user equipment on aircraft  302  and aircraft  304  to external packet data networks by being the point of exit and entry of traffic for the user equipment. Policy and charging rules function  318  interfaces with packet data network gateway  316  and supports service data flow detection, policy enforcement, and flow-based charging. Home subscriber server  320  is a central database that stores user-related and subscription-related information. Home subscriber server  320  provides mobility management, call and session establishment support, user authentication, and access authorization. 
     Referring to  FIG. 4 , implementation of WiFi calling and texting on the aircraft facilitates video or voice calls and texting from users in flight to terrestrial users. On the aircraft, an interim layer  706  converts a private IP address of the user on the aircraft to a public IP addressing scheme. For example, interim layer  706  may map multiple users on one aircraft to a single IP address for the aircraft. In the core implementation, gateway  710  assigns a dedicated communications channel or circuit to the IP address allows the user on the aircraft to communicate using Voice over Internet Protocol (VoIP) or to communicate to an endpoint having a terrestrial phone number through circuit-switched core  712 . 
     Referring back to  FIG. 3 , aircraft  302  and aircraft  304  may separately communicate with non-terrestrial relay points (e.g., satellites  303  and  305 ), which communicate with satellite core  311  and an IP multimedia subsystem to provide services to users. Although the non-terrestrial relay point is described herein as being a satellite relay point (e.g., stationary or geostationary satellite), other embodiments of the non-terrestrial relay point include low duration aircraft, long duration aircraft (e.g., high-altitude platform aircraft (HAPS) or similar system), aerostat, or other non-terrestrial relay point. Traffic from the non-terrestrial relay point is delivered to an appropriate terrestrial termination point or directly to another aircraft, thus allowing a user-to-user communication or aircraft-to-aircraft communication. Note that the satellite communications system and the air-to-ground communications system operate independently and a particular aircraft may utilize one, the other, or both at a particular time. 
     Referring to  FIG. 5 , a hybrid in-flight communications system integrates aircraft communications systems and traffic management of the aircraft air-to-ground communications and satellite communications to provide gate-to-gate connectivity to users on an aircraft. Virtual tunnel aggregator  322  establishes individual communications sessions using generic routing encapsulated (GRE) tunnel communications between the user on aircraft  304  using either the satellite communications system core or mobility core  1302 . As referred to herein, a user on an aircraft includes passengers, airline personnel, an in-flight entertainment system, and the avionics system. Virtual tunnel aggregator  322  may include one or more general-purpose processors and corresponding locations storing software or firmware instructions configured to execute on the one or more general purpose processors, and/or one or more application-specific integrated circuits configured to accomplish tasks set forth herein. 
     Referring to  FIGS. 5 and 6 , a session between user equipment  814  on aircraft  304  and a device coupled to mobility core  1302  may be established using virtual tunnel aggregator  322 , and a voice or text communications network  804  or an over-the-top (OTT) server  802 , i.e., a server that delivers audio, video, or other media over the Internet without a multiple-system operator (i.e., multi-system operation, e.g., cable operator) being involved in the control or distribution of the content. Data may be communicated between voice or text communications device  804  and user equipment  814  using aircraft equipment  822 , which includes network module/multi-link router  812  and aircraft access point  820 , and only one of satellite system  808  and air-to-ground system  810 . Aircraft access point  820  may be a small cell, a wireless access point, an in-flight entertainment system, or other user or user equipment interface that coupled to the in-flight network. Virtual tunnel aggregator  322  and the network module/multi-link router  812  establish a session based on traffic classification. High-latency intolerant sessions may be allocated air-to-ground bandwidth while high-latency tolerant traffic is allocated to the satellite communications system. 
     Referring to  FIGS. 5 and 7 , data may be communicated between OTT server  802  and user equipment  814  on an aircraft using virtual tunnel aggregator  322  and both satellite communications system  808  and an air-to-ground system  810  via aircraft equipment  822 , which includes network module/multi-link router  812  and aircraft access point  820 . Virtual tunnel aggregator  322  and network module/multi-link router  812  implement a network layer (i.e., layer  3  of the seven-layer Open Systems Interconnection (OSI) model of computer networking) solution that partitions the data traffic into a portion communicated over satellite communications system  808  and a portion communicated over the air-to-ground system  810  based on layer  3  information (e.g., link state and available bandwidth). However, this layer  3  solution TCP may have poor performance if packets arrive out-of-order and some applications may behave poorly under high jitter. 
     Referring to  FIGS. 5 and 8 , in another configuration of an in-flight communications system a transport layer (i.e., layer  4  of the seven-layer OSI model) solution partitions the data traffic into a portion communicated over satellite communications system  808  and a portion communicated over the air-to-ground system  810  based on layer  3  information (e.g., link state and available bandwidth) but also bundles all traffic of one TCP connection on one link. Referring to  FIGS. 5 and 9 , in another embodiment, a TCP proxy (e.g., TCP proxy  902  or TCP proxy  916 ) partitions the data traffic into a portion communicated over satellite communications system  808  and a portion communicated over the air-to-ground system  810  to another TCP proxy of virtual tunnel aggregator  322  and a multipath TCP connection that includes multiple paths. 
       FIG. 10  illustrates exemplary in-flight connectivity equipment included in aircraft equipment  822  of  FIGS. 5-9  that can provide simultaneous and coordinated communications services over air-to-ground and satellite communications systems. Note that as referred to herein, equipment on the aircraft includes equipment that is attached externally to any surface of the aircraft, equipment that is inside the aircraft, and/or equipment that is otherwise part of the aircraft. In-flight connectivity on-board equipment includes cabin equipment  1402 , aircraft system equipment  1410 , and external aircraft antennas  1460 . Users on the aircraft may communicate in-flight using a communications device (e.g., smartphone, laptop, tablet, gaming system, seatback display, wearable device, machine-to-machine (M2M) module, or other suitable equipment used by an end-user to communicate) that may be coupled to aircraft equipment  822  (e.g., a communications terminal in a seatback or armrest) by a transmission line or by a wireless interface configured to communicate using a wireless networking technology (e.g., Bluetooth, IEEE 802.11 wireless local area network technologies, Long-Term Evolution (LTE), second-Generation (2G), third-Generation (3G), fourth-generation (4G), LTE-Advanced, LTE in unlicensed spectrum (LTE-U), Global System for Mobile Communications (GSM), Enhanced Data rates for GSM Evolution (EDGE), High Speed Packet Access (HSPA), Universal Mobile Telecommunications System (UMTS), and Worldwide Interoperability for Microwave Access (WiMax) wireless communications, or other wireless communications protocols, which use one or more of Code Division Multiple access (CDMA), Time Division Multiple Access (TDMA), Frequency Division Multiple Access (FDMA), Wideband CDMA (WCDMA), Orthogonal Frequency Division Multiple Access (OFDMA), or other suitable communications techniques). The wireless interface includes one or more antennas. For example, the aircraft cabin may include antenna  1404  coupled to a radio access node compliant with a wide-area network standard, antenna  1406  coupled to a WiFi radio access point  1414 , or other antenna (e.g., an antenna in seat display terminal  1408  coupled to receive signals over a short range). Note that individual antennas may provide wireless service within the aircraft using distributed antenna system including a network of spatially separated antenna nodes coupled to an access point via a transport medium. 
     In at least one embodiment, aircraft system equipment  1410  includes small cell  1412 , which is a low-powered radio access node that operates in a predetermined spectrum (licensed or unlicensed spectrum) on the aircraft. Small cell  1412  may be compliant with LTE, 2G, 3G, 4G, LTE-Advanced, LTE-U, GSM, EDGE, HSPA, UMTS, and WiMax wireless communications, or other wireless protocol typically used for wide-area networking that uses one or more of CDMA, TDMA, FDMA, WCDMA, OFDMA, or other suitable communications techniques. Small cell  1412  facilitates use of personal equipment of passengers being used, unchanged, on the aircraft, and reduces the need for additional handsets to be provided on the aircraft by an aircraft operator. Additional small cells (not shown) and corresponding antennas may be included to facilitate use of personal equipment compatible with various different wide-area networking standards and/or small cell  1412  may be compliant with multiple standards. Aircraft system equipment  1410  may also include access point  1414  that is compliant with a local area network protocol (e.g., WiFi) and that serves as an aircraft hotspot to user personal equipment configured compliant with such communications standards. Access point  1414  facilitates use of user personal equipment over regular communications spectrum on the aircraft and reduces the need for additional handsets to be provided by the aircraft operator. Additional access points and corresponding antennas may be included to facilitate use of personal equipment compatible with various different local-area networking standards. 
     In at least one embodiment, aircraft system equipment  1410  includes seat display terminals in the seat-backs or other suitable portion of the aircraft cabin. Each seat display terminal  1408  is coupled to in-flight entertainment system  1428 , which may provide various types of programming to users including one or more of interactive direct-broadcast satellite television, Internet, and audio programming, without requiring use of a user&#39;s own personal user equipment. In addition, user equipment may directly connect to the in-flight entertainment system using a port in a seat display terminal or other portion of the aircraft cabin. Aircraft system equipment  1410  may also include interface  1416 , which includes one or more interface for avionics and crew. Interface  1416  may communicate with one or more of the electronic systems used on the aircraft, including communications, navigation, global positioning systems, and/or other electronic systems of the aircraft to an aircraft operator, air traffic control, or other recipient (e.g., nearest local or government authorities). Avionics and crew interface  1416  may also provide crew with configuration and override access to other services being provided by aircraft system equipment  1410 . For example, the crew may manually disable and/or configure small cell  1412 , access point  1414 , in-flight entertainment system  1428 , modems (e.g., digital units  1432 ,  1434 ,  1436 , and  1437 ) and/or components of power amplifier shelf  1438  for the entire aircraft and/or for individual user access. Avionics and crew interface  1416  may also provide a communications interface for crew to the aircraft operator, air traffic control, or other recipients (e.g., nearest local or government authorities). 
     Still referring to  FIG. 10 , aircraft system equipment  1410  includes in-flight connectivity controller  1418 . The control functions may be performed by a stand-alone controller or distributed across multiple computers, microprocessors, or other suitable devices. In-flight connectivity controller  1418  includes router  1420 , server  1422 , storage  1424  and may include an additional management functions control unit  1426 . Each of the elements of in-flight connectivity controller  1418  may include one or more general-purpose processors and corresponding locations in storage facility  1424  storing software or firmware instructions configured to execute on the one or more general purpose processors, and/or one or more application-specific integrated circuits configured to accomplish tasks set forth herein. In addition, storage facility  1424  may include data associated with operation of in-flight connectivity controller  1418 , e.g., routing information and other in-flight connectivity system configuration information. Router  1420  forwards data packets between the aircraft communications systems (e.g., avionics and crew interface  1416 , small cell  1412 , access point  1414 , and in-flight entertainment system  1428 ) and transceivers for communications external to the aircraft. Note that access points  1412 ,  1414 , and other wireless access points may communicate with user equipment using different power levels, different frequencies, different channels, different power spectral density masks, and/or different communications protocols. Management controller  1426  establishes routing encapsulation tunnels (e.g., generic routing encapsulation tunnels) between the users of the in-flight connectivity services and services provided by terrestrial communications systems. 
     In general, router  1420  receives and assembles or disassembles packets before forwarding them on to an internal or external network, respectively. In addition, management controller  1426  may perform registration of user equipment on the aircraft to the in-flight communications network, encryption, e.g., secure shell encryption, transport layer security, or secure sockets layer encryption, and Doppler shift compensation based on signal frequency and velocity of the aircraft received from the avionics. In other embodiments, the Doppler shift compensation is performed by digital units  1432 ,  1434 ,  1436 , and  1437  based on information received from the avionic directly or indirectly via in-flight connectivity controller  1418 . In addition, in-flight connectivity controller  1418  allocates aircraft-area bandwidth (e.g., bandwidth for communications using the in-flight communications network in regions internal or proximate to the aircraft including the aircraft cabin, the aircraft cockpit, cargo area, and other regions internal or proximate to the aircraft within range of signals transmitted using cabin equipment  1402 ) to individual sessions on the airplane (i.e., between a user and management controller  1426 ) according to the prioritization level of equipment on the aircraft. The prioritization level may be based on a type of the equipment on the aircraft. The prioritization levels may include a prioritization level of aircraft passenger user equipment, a prioritization level of avionics equipment, a prioritization level of an in-flight entertainment system, and a prioritization level of aircraft personnel communications equipment. 
     In at least one embodiment, aircraft system equipment  1410  includes air-to-ground digital unit  1432 , satellite digital unit  1434 , and additional satellite digital unit  1436 , which perform modulation and demodulation of signals communicated between in-flight connectivity controller  1418  and relay points external to the aircraft (e.g., a terrestrial relay point or a non-terrestrial relay point). Air-to-ground digital unit  1432  may be compliant with one or more wide-area network standards (e.g., LTE, 2G, 3G, 4G, LTE-Advanced, LTE-U, GSM, EDGE, HSPA, UMTS, and WiMax wireless communications, or other wireless protocol typically used for wide-area networking that uses one or more of CDMA, TDMA, FDMA, WCDMA, OFDMA, or other suitable communications techniques). Satellite digital unit  1434  may be compliant with one or more of Super High Frequency (SHF) band (e.g., 3 to 30 GHz), C band (e.g., 4 GHz to 8 GHz), G band (e.g., NATO G band of 4 GHz to 6 GHz, IEEE G band of 110 GHz to 300 GHz, or obsolete G band 140 MHz to 220 MHz), H Band (e.g., 6 GHz to 8 GHz), Ku band (e.g., 12 GHz to 18 GHz), Ka band (e.g., 26.5 GHz to 40 GHz), L band (e.g., 40 GHz to 60 GHz or 1 GHz to 2 GHz), X band (e.g., 7 GHz to 12 GHz), and F band (e.g., 3 GHz to 4 GHz), frequency band mobility network communications. Additional digital unit  1436  includes transmitter and receiver digital circuitry for other frequency bands (e.g., 14 GHz frequency band or other frequency bands that are separately regulated). Air-to-ground digital unit  1432 , satellite digital unit  1434 , and additional digital unit  1436  include circuits that implement digital signal transmitter operations and digital signal receiver operations. 
     Power amplifier shelf  1438  includes radio units that correspond to the standards implemented by the various digital units. Each of radio units  1440 ,  1442 ,  1444 , . . . ,  1452  includes circuits (e.g., transceivers) that perform analog transmitter and analog receiver operations for signals communicated to and from one or more corresponding antennas  1462 ,  1464 ,  1466 , . . . ,  1474 . Exemplary operations include digital-to-analog conversion, analog modulation, mixing with a carrier signal, power amplification, sampling, analog demodulation, filtering, applying a power-spectral density mask, and/or other suitable radio frequency communication operations. Note that the receivers may process multiple signals from Multiple-Input Multiple-Output (MIMO) embodiments or multiple signals received over multiple antennas using diversity combining or other diversity techniques. An individual antenna may be shared by multiple radio bands or a multi-band antenna, antenna switch, combiner or other suitable technique may be used. Radio units  1440 ,  1442 ,  1444 , and  1446  perform those transmit and receiver operations for the frequency bands that correspond to the different air-to-ground standards, e.g., S frequency band, C and D blocks of the WCS frequency band, A, B, C, and D blocks of the WCS frequency band, and mobility frequency bands, respectively using corresponding antennas on the aircraft (antennas  1462 ,  1464 ,  1466 , and  1468 , respectively). Note that in one embodiment of air-to-ground communications system, the C and D frequency bands are used as primary frequency bands and additional bands (e.g., A and B frequency bands) are used for communications with a Remote Radio Head (RRH) of the distributed base station. Similarly, radio unit  1448  performs transmit and receive operations for communications between antenna  1470  and satellite digital unit  1434  and the 14 GHz radio unit  1450  performs transmit and receive operations for communications between antenna  1472  and additional digital unit  1436 . 
     In at least one embodiment, aircraft system equipment  1410  includes short range wireless digital unit  1437  and short-range wireless radio unit  1452  coupled to antenna  1474 . Those elements facilitate communications and updates of the in-flight entertainment system using short-range wireless communications (e.g., WiFi), without requiring separate equipment. In addition, those elements may be used to provide communications services to users while an aircraft is on the ground (e.g., parked at a gate) using a terrestrial WiFi system coupled to the Internet. Additional digital units, radio units, and antennas may be included to provide other coverage, e.g., to provide regular terrestrial communications to a terrestrial wireless communications system. In embodiments of an in-flight connectivity system, additional eNodeBs are located close to or on airport property to facilitate communications from the aircraft while parked at an airport gate. In at least one embodiment of the in-flight connectivity system, multiple frequency bands share the same antenna or a multi-band antenna, antenna switch, combiner or other suitable technique may be used. In addition, note that although only one antenna is illustrated per frequency band, multiple antennas may be used for each frequency band, each antenna being strategically located on the fuselage to provide more continuous communications coverage based on the aircraft orientation with respect to a terrestrial antenna. For example, the antennas may have different angles with respect to a terrestrial antenna to increase coverage during aircraft banking. Cabin equipment  1402 , aircraft system equipment  1410 , and external aircraft antennas  1460  facilitate multiple streams of data being communicated to/from users of an aircraft (e.g., seat display terminal  1408 , user equipment using small cell  1412 , user equipment using access point  1414 , and aircraft avionics and crew interface  1416 ) and virtual tunnel aggregator  322  using air-to-ground and satellite communications systems. In at least one embodiment, aircraft antennas are implemented using multi-band antennas. 
     Referring to  FIG. 12 , management controller  1426  establishes routing encapsulation tunnels (e.g., generic routing encapsulation tunnels) between the users of the in-flight connectivity services and virtual tunnel aggregator  322  of  FIG. 5 . In response to a registration operation of aircraft  302  using an aircraft identity stored in storage  1424 , virtual tunnel aggregator  322  allocates bandwidth to upstream and/or downstream communications with aircraft  304 . That bandwidth allocation may be partitioned between the air-to-ground system, the satellite communications system, and/or other communications system based on a link budget, aircraft identity type, traffic characteristics, a subscription profile for the aircraft, or other suitable aircraft status and location. 
     Referring to  FIG. 11 , a link budget for aircraft  304  accounts for all of the gains (e.g., due to antenna diversity and frequency hopping schemes) and losses from the transmitter and the receiver through the atmosphere. The link budget accounts for attenuation of transmitted signals due to propagation, as well as antenna gains, feedline, and miscellaneous losses. Since losses due to the atmosphere vary with altitude, the link budget may be estimated based on a single sector view of a particular radius of the position of the aircraft with respect to the cell tower (e.g., center point to 75 kilometers from the cell tower), using a maximum altitude, although the losses may be reduced for aircraft flying at lower altitudes. In at least one embodiment, a communications network bases the aircraft link budget on multiple predetermined sectors (e.g., maximum altitude to approximately 10,000 feet and approximately 10,000 feet to approximately ground). In addition, the link budget accounts for gain due to the number of antennas used, e.g., a multiplication factor for 2×2 multiple-input, multiple output (MIMO). 
     In at least one embodiment of the in-flight connectivity network, a communications system (e.g., the air-to-ground communications system or the satellite communications system) allocates bandwidth to a particular aircraft according to aircraft type. For example, each aircraft includes a subscriber identity module that indicates the aircraft type, e.g., a commercial jet having capacity for n passengers, a private jet having capacity for m passengers, a military aircraft, a drone aircraft, or other type of aircraft. Mobility management entity  312  of  FIG. 5  may allocate bandwidth to a particular aircraft by prioritizing an aircraft with a greater number of actual passengers (e.g., aircraft  304  of  FIG. 12 ) over a smaller aircraft transporting fewer passengers (e.g., aircraft  302  of  FIG. 12 ). Other prioritization schemes may be used, e.g., prioritization based on subscription services of one or more aircraft operators associated with individual aircraft, or other suitable schemes. 
     Once an aircraft is allocated bandwidth of a particular communications system, in-flight connectivity controller  1418  of  FIG. 10  allocates that bandwidth to user equipment associated with individual users on the aircraft. As referred to herein, a user is one of a passenger, a crew member, the aircraft avionics system, or the in-flight entertainment system. Each user and/or user type may be granted different priority for its associated equipment. For example, aircraft avionics may be granted highest priority and equipment associated with passengers may be granted lowest priority. In at least one embodiment, in-flight connectivity controller  1418  prioritizes use of any air-to-ground bandwidth allocated to the aircraft over satellite system bandwidth due to lower latency characteristic and/or lower cost of the air-to-ground communications as compared to the latency and cost of satellite communications. That is, in-flight connectivity controller  1418  may allocate all of the air-to-ground communications bandwidth before allocating any satellite communications bandwidth or partitions bandwidth amongst different users (e.g., allocates satellite communications bandwidth to the in-flight entertainment system and then to other users). 
     Referring to  FIG. 13 , air-to-ground communications system and a satellite communications system grant bandwidth to in-flight connectivity controller  1418  ( 202 ) and in-flight connectivity controller  1418  prioritizes the air-to-ground bandwidth. For example, in-flight connectivity controller  1418  determines whether sufficient air-to-ground system bandwidth is available for sensor data transmission from the aircraft ( 204 ), i.e., whether the total used air-to-ground bandwidth is less than or equal to a threshold, e.g., the maximum air-to-ground bandwidth allocated to the aircraft. If the air-to-ground bandwidth is insufficient, in-flight connectivity controller  1418  determines whether it is economical to transmit the sensor data from the aircraft using satellite communications system bandwidth allocated to the aircraft ( 208 ). If use of satellite bandwidth is economical, in-flight connectivity controller  1418  throttles user Internet services and/or other services otherwise allocated to satellite communications system (e.g., via the in-flight entertainment system) ( 218 ) to provide bandwidth for the sensor data transmission. In-flight connectivity controller  1418  determines whether any remaining air-to-ground bandwidth is sufficient for avionics data communications ( 206 ). If the air-to-ground bandwidth is insufficient, in-flight connectivity controller  1418  determines whether it is economical to send the flight-deck data transmission using satellite communications system bandwidth ( 208 ). If use of satellite bandwidth is economical, in-flight connectivity controller  1418  throttles user Internet services and/or other services allocated satellite communications system bandwidth ( 218 ) to provide bandwidth for avionics data transmission. 
     In addition, in-flight connectivity controller  1418  determines whether any air-to-ground bandwidth allocation is sufficient for flight crew services data transmission ( 210 ). If the air-to-ground bandwidth is insufficient, in-flight connectivity controller  1418  determines whether it is economical to send the flight crew services data transmission using any remaining satellite communications system bandwidth ( 208 ). If use of satellite bandwidth is economical, in-flight connectivity controller  1418  throttles user Internet services and/or other user services allocated satellite communications system bandwidth ( 218 ) to provide bandwidth for flight crew services data transmission. In-flight connectivity controller  1418  then determines whether the air-to-ground system bandwidth is sufficient for supporting other Internet service, e.g., to other user equipment on the aircraft ( 212 ). If not, then in-flight connectivity controller  1418  throttles the user Internet services ( 214 ). If the bandwidth is sufficient, then, all of the Internet services are communicated using an air-to-ground modem ( 216 ). Otherwise, in-flight connectivity controller  1418  throttles the other user Internet services and allocates any remaining service requests to the satellite system, if possible ( 214 ). Note that while the single air-to-ground transmission pipe is managed based on a particular prioritization scheme, and relies on the satellite transmission in cases of insufficient bandwidth, other prioritization schemes may be used. In at least one embodiment of in-flight connectivity controller  1418 , an override selection may be made that gives absolute priority to aircraft avionics under certain circumstances (e.g., emergency communications). In at least one embodiment, in-flight connectivity controller  1418  prioritizes different passenger services. For example, the in-flight entertainment system that is delivered to seat display terminals may be granted higher priority than other services being provided to user equipment in the aircraft cabin. 
     Referring back to  FIG. 5 , in at least one embodiment, the air-to-ground communications system is used for communications sessions that have relatively high-latency intolerance (e.g., video, voice-over-Internet-protocol, chatting, and gaming). However, under certain circumstances, the air-to-ground communications system may have poor performance (e.g., when the aircraft is located over a large body of water or performs a banking turn or engages in other orientation that degrades the air-to-ground signal quality), and in-flight communications system (e.g., in-flight connectivity controller  1418  of  FIG. 10 ) coordinates a hand-off of a communications session from the air-to-ground communications system to the satellite communications system. Any suitable handover technique may be used. The air-to-ground system views one or more satellite systems as just other eNodeBs and uses simultaneous tunnels for the same user. However, when the air-to-ground communications system signal quality improves, another handoff occurs to restore the communications session to the air-to-ground communications system. Note that under other circumstances, satellite communications may be selected and handoff to the air-to-ground communications system may occur in response to degradation of the satellite communications system or improvement to the air-to-ground signal quality. Accordingly, when the satellite communications system performance improves, another handoff occurs to restore the communications session from the air-to-ground communications system to the satellite communications system. In situations where bandwidth of a selected communications system is insufficient to satisfy a minimum required capacity of a particular communications session, in-flight connectivity controller  1418  queues the communications session. In addition, in-flight connectivity controller  1418  adjusts bandwidth allocated to any particular communications session in response to an event having a prioritization level higher than the prioritization level of the communications session (e.g., avionics or crew communications needing additional bandwidth for emergency communications). 
     Structures described herein may be implemented using software executing on a processor (which includes firmware) or by a combination of software and hardware. Software, as described herein, may be encoded in at least one tangible computer readable medium. As referred to herein, a tangible computer-readable medium includes at least a disk, tape, or other magnetic, optical, or electronic storage medium. 
     The description set forth herein is illustrative, and is not intended to limit the scope of the following claims. Variations and modifications of the embodiments disclosed herein may be made based on the description set forth herein, without departing from the scope and spirit of the following claims.