Patent Publication Number: US-9426512-B2

Title: Aircraft in-flight entertainment system having a dual-beam antenna and associated methods

Description:
RELATED APPLICATION 
     This application is a continuation of U.S. patent application Ser. No. 12/252,272 filed Oct. 15, 2008, the entire contents of which are incorporated herein by reference; and this application claims the benefit of continuation-in-part U.S. patent application Ser. No. 12/047,349 filed Mar. 13, 2008, the entire contents of which are incorporated herein by reference; and this application claims the benefit of U.S. Provisional Application Ser. No. 60/980,298 filed Oct. 16, 2007, the entire contents of which are incorporated herein by reference. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to the field of aircraft systems, and more particularly, to an aircraft in-flight entertainment (IFE) system having a dual-beam antenna for satellite communications. 
     BACKGROUND OF THE INVENTION 
     Commercial aircraft carry millions of passengers each year. For relatively long international flights, wide-body aircraft are typically used. These wide-body aircraft include multiple passenger aisles and are considerably larger and have considerably more space than typical so-called narrow-body aircraft. Narrow-body aircraft carry fewer passengers shorter distances, and include only a single aisle for passenger loading and unloading. Accordingly, the available space for ancillary equipment is somewhat limited on a narrow-body aircraft. 
     Wide-body aircraft may include full audio-on-demand and video-on-demand in-flight entertainment systems for passenger enjoyment during relatively long flights. Typical wide-body aircraft in-flight entertainment systems may include cabin displays, or individual seatback displays. Movies or other stored video programming is selectable by the passenger, and payment is typically made via a credit card reader at the seat. For example, U.S. Pat. No. 5,568,484 to Margis discloses a passenger in-flight entertainment system with an integrated telecommunications system. A magnetic stripe credit card reader is provided at the telephone handset and processing to approve the credit card is performed by a cabin telecommunications unit. 
     In addition to prerecorded video entertainment, other systems have been disclosed including a satellite receiver for live television broadcasts, such as disclosed in French Patent No. 2,652,701 and U.S. Pat. No. 5,790,175 to Sklar at al. The Sklar at al. patent also discloses such a system including an antenna and its associated steering control for receiving both RHCP and LHCP signals from direct broadcast satellite (DBS) services. The video signals for the various channels are then routed to a conventional video and audio distribution system on the aircraft which distributes live television programming to the passengers. 
     In addition, U.S. Pat. No. 5,801,751 also to Sklar at al. addresses the problem of an aircraft being outside of the range of satellites, by storing the programming for delayed playback, and additionally discloses two embodiments: a full system for each passenger and a single channel system for the overhead monitors for a group of passengers. The patent also discloses steering the antenna so that it is locked onto RF signals transmitted by the satellite. The antenna steering may be based upon the aircraft navigation system or a GPS receiver along with inertial reference signals. 
     Current aircraft in-flight entertainment systems may also provide television programming and Internet data. Such systems may include a shared satellite antenna for receiving the television programming and the Internet data, headend electronic equipment at a central location in the aircraft, a cable distribution network extending throughout the passenger cabin, and electronic demodulator and distribution modules spaced within the cabin for different groups of seats. Many systems require signal attenuators or amplifiers at predetermined distances along the cable distribution network. In addition, each passenger seat may include an armrest control and seatback display. In other words, such systems may be relatively heavy and consume valuable space on the aircraft. 
     Space and weight are especially difficult constraints for a narrow-body aircraft. U.S. Pat. Nos. 6,741,841 and 7,321,383 both disclose an aircraft in-flight entertainment system providing television programming and Internet data using a shared satellite antenna. The satellite antenna may be a multi-beam or dish antenna, for example. However, these patents fail to disclose the specifics of implementing a multi-beam phased array antenna operating as part of an in-flight entertainment system for simultaneously receiving television programming and Internet data. 
     SUMMARY OF THE INVENTION 
     In view of the foregoing background, an object of the present invention is to provide an aircraft in-flight entertainment (IFE) system having a dual-beam antenna for receiving television programming and Internet data. 
     This and other objects, advantages and features in accordance with the present invention are provided by an in-flight entertainment (IFE) system comprising a radome to be carried by the aircraft, and a dual-beam satellite antenna and at least one positioner coupled thereto to be carried by the aircraft and protected by the radome. The dual-beam satellite antenna may generate dual antenna beams for television programming and Internet data from respective spaced apart satellites. The dual-beam satellite antenna may comprise a first aperture for receiving the television programming, and a second aperture adjacent the first aperture for receiving the Internet data. A television programming distribution system may be carried by the aircraft and coupled to the dual-beam satellite antenna to provide television programming within the aircraft. At least one access point may be carried by the aircraft and coupled to the dual-beam satellite antenna to provide a wireless local area network (WLAN) within the aircraft for the Internet data. The first aperture may comprise a first phased array, and the second aperture may comprise a second phased array. 
     The at least one positioner may comprise a first positioner to position the first aperture toward one of the spaced apart satellites, and a second positioner to position the second aperture toward the other one of the spaced apart satellites. A controller may be coupled to the positioners. 
     The dual-beam satellite antenna may simultaneously generate the dual antenna beams, with each antenna beam having a respective antenna beam boresight. The dual-beam satellite antenna may also be configured to transmit to the satellite providing the Internet data. 
     The first and second apertures may have an antenna beam offset between their respective antenna beams. The at least one positioner may comprise a common positioner for positioning both the first and second apertures at a same time while maintaining the antenna beam offset. The IFE system may further comprise an offset controller to be carried by the aircraft and coupled to the first and second apertures for adjusting the antenna beam offset. 
     The first and second apertures may each have different orthogonal polarizations associated therewith. The first aperture may provide two orthogonal polarizations toward one of the satellites, and the second aperture may provide two different orthogonal polarizations toward the other satellite. The IFE system may further comprise at least one polarization correction module to adjust at least one of the polarizations based upon aircraft position. More particularly, the first aperture may provide orthogonal polarizations toward one of the satellites and the second aperture may provide different orthogonal polarizations toward the other satellite. The aircraft IFE system may further comprise a first polarization correction module associated with the first aperture for adjusting the corresponding polarizations based upon aircraft position, and a second polarization correction module associated with the second aperture for adjusting the corresponding polarizations based upon aircraft position. 
     The first aperture may be configured to operate within a frequency range of 12 to 18 GHz, and the second aperture may be configured to operate within a frequency range of 20 to 30 GHz. The television programming distribution system may comprise cabling extending throughout the aircraft, and at least one video display coupled to the cabling for displaying the television programming. The at least one access point may communicate with personal electronic devices (PEDs) within the aircraft. The at least one access point may comprise a pico-cell, and the WLAN may comprise at least one of an 802.11 WLAN and an 802.16 WLAN. 
     Another aspect is directed to a method for operating an aircraft in-flight entertainment (IFE) system for an aircraft and comprising a radome to be carried by the aircraft, a dual-beam satellite antenna to be protected by the radome, at least one positioner to be carried by the aircraft and coupled to the dual-band satellite antenna, a television programming distribution system to be carried by the aircraft and coupled to the dual-beam satellite antenna to provide television programming within the aircraft, and at least one access point to be carried by the aircraft and coupled to the dual-beam satellite antenna to provide a wireless local area network (WLAN) within the aircraft. The method comprises controlling the at least one positioner so that the dual-beam satellite antenna generates dual antenna beams for television programming and Internet data from respective spaced apart satellites. The dual-beam satellite antenna may comprise a first aperture for receiving the television programming, and a second aperture adjacent the first aperture for receiving the Internet data. The method may further comprise providing the television programming to aircraft passengers via the television programming distribution system, and providing the Internet data to the aircraft passengers via the WLAN. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram of an air-to-ground communications network in accordance with the present invention. 
         FIG. 2  is a schematic diagram of another embodiment of the air-to-ground communications network with passenger carried equipment on the aircraft in accordance with the present invention. 
         FIG. 3  is a schematic diagram of another embodiment of the PED shown in  FIG. 2  with the translator device integrated therein. 
         FIG. 4  is a schematic diagram of the air-to-ground communications network in which predetermined web pages are transmitted over an airport data link for storage on the aircraft in accordance with the present invention. 
         FIG. 5  is a screen shot from a PED of an interactive map corresponding to the flight path of the aircraft in accordance with the present invention. 
         FIG. 6  is a screen shot from a PED of an interactive map corresponding to the destination of the aircraft in which different information categories are displayed in accordance with the present invention. 
         FIG. 7  is a schematic diagram of the air-to-ground communications network in which network selection controllers are used for selecting between satellite or air-to-ground communications in accordance with the present invention. 
         FIG. 8  is a schematic diagram of the air-to-ground communications network in which hard handoff controllers are used for handing off the aircraft between base stations in accordance with the present invention. 
         FIG. 9  is a schematic diagram of the different content delivery channels available for distribution to the aircraft passengers in accordance with the present invention. 
         FIG. 10  is a schematic diagram of the aircraft illustrating the different ranges in which data communications is received in accordance with the present invention. 
         FIG. 11  is a schematic diagram of an aircraft in-flight entertainment system operating with a satellite antenna in accordance with the present invention. 
         FIGS. 12A and 12B  are more detailed schematic block diagrams of an embodiment of the in-flight entertainment system as shown in  FIG. 11 . 
         FIG. 13  is a schematic rear view of a seatgroup supporting the in-flight entertainment system as shown in  FIG. 11 . 
         FIG. 14  is a more detailed schematic block diagram of a first embodiment of an antenna-related portion of the in-flight entertainment system as shown in  FIG. 11 . 
         FIG. 15  is a side elevational view of the antenna mounted on the aircraft of the in-flight entertainment system as shown in  FIG. 11 . 
         FIG. 16  is a more detailed schematic block diagram of a second embodiment of an antenna-related portion of the in-flight entertainment system as shown in  FIG. 11 . 
         FIG. 17  is a schematic diagram of the overall components of an aircraft in-flight entertainment system including a multi-beam antenna for interfacing with two different satellites in accordance with the present invention. 
         FIG. 18  is a more detailed schematic block diagram of one embodiment of an electrically steered multi-beam phased array antenna in accordance with the present invention. 
         FIG. 19  is a schematic block diagram of the polarization correction module as shown in  FIG. 18 . 
         FIG. 20  is a block diagram of one embodiment of the phased array antenna in accordance with the present invention. 
         FIG. 21  is a block diagram of another embodiment of the phased array antenna in accordance with the present invention. 
         FIG. 22  is a more detailed schematic block diagram of another embodiment of an electrically steered multi-beam phased array antenna in accordance with the present invention. 
         FIG. 23  is a block diagram of a top plan view one embodiment of a mechanically steered dual-beam antenna in accordance with the present invention. 
         FIG. 24  is a block diagram of a side elevation view of the mechanically steered dual-beam antenna as shown in  FIG. 23 . 
         FIG. 25  is a block diagram of a top plan view of another embodiment of the mechanically steered dual-beam antenna as shown in  FIG. 23 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Like numbers refer to like elements throughout, and prime notation is used to indicate similar elements in alternative embodiments. 
     Referring initially to  FIG. 1 , an air-to-ground communications network  100  will be discussed in which passengers within an aircraft  120  are able to communicate over an air-to-ground interface  200  using their own personal electronic devices (PEDs)  130 . PEDs  130  include personal mobile smart phones or telephones (cellular and PCS), personal digital assistants, wireless email devices, wireless equipped laptop computers having Wi-Fi/WiMax capability, air cards, or WiFi equipped MP3 players, for example. 
     As will be discussed in greater detail below, the air-to-ground communications network  100  may be considered as a data-based network as compared to a terrestrial voice-based network that also supports data. A data-based network supports emails and text messaging without having to specifically take into account the additional requirements (including latency) associated with traditional two-way, full duplex live conversational voice. However, the air-to-ground communications network  100  supports voice capability, as VoIP, and can send multimedia in the form of streaming video, multimedia web surfing, still pictures, music, etc. As a result, hard handoffs may be used between the ground-based base stations  140  as the aircraft  120  is in flight. Soft handoffs are often used for voice-based networks, which negatively impacts the amount of frequency spectrum needed for a handoff. 
     The air-to-ground network  100  is not constrained to use air interfaces deployed for terrestrial networks. An air interface that is not used for terrestrial networks may be used. The air-to-ground interface  200  is used to communicate with the ground-based base stations  140 . Each base station  140  illustratively interfaces with the public switched telephone network (PSTN)  141  and an Internet service provider (ISP)  142  through a switch  143  for providing email and text messaging services. The PSTN  141  and the ISP  142  are illustrated for only one of the base stations  40 . Alternatively, an Internet connection  42  could only be provided and not a PSTN connection  41 . 
     In the United States, for example, there are approximately 100 base-stations  140  positioned to directly support the air-to-ground communications network  100  disclosed herein. This is particularly advantageous since the frequency band of the air-to-ground interface  200  is different than the frequency bands associated with cellular mobile telecommunication systems. In the illustrated example of the air-to-ground communications network  100 , the allocated frequency spectrum of the air-to-ground interface  200  is based on a paired spacing of 851 MHz and 896 MHz, with 0.5 MHz available at each frequency. 
     In contrast, one portion of the radio spectrum currently used for terrestrial wireless communications companies is in the 824-849 MHz and 869-894 MHz bands. PCS is a wireless communications network that operates at a radio frequency of 1.9 GHz. Internationally, other frequencies and bands have been allocated for licensed wireless communications, but they do not operate using the paired spacing of 851 MHz and 896 MHz. 
     In the illustrated embodiment, equipment has been installed on the aircraft  120  so that the aircraft appears as a hotspot or intranet to the PEDs  130 . Nodes or access points  160  are spaced throughout the cabin area of the aircraft  120  providing 802.11 services (i.e., Wi-Fi) or 802.16 services (i.e., WiMax), for example. In addition, access to the network  100  could be through an on-board pico-cell in which the PEDs  130  communicate therewith using cellular or PCS functions. A pico-cell is analogous to a Wi-Fi or WiMax access point  160 . 
     The access points  160  are illustratively connected to an on-board server  162  and an air-to-ground transceiver  152 . The server  162  includes a data memory cache  155  and a data traffic controller  158 . An air-to-ground antenna  154  is coupled to the air-to-ground transceiver  152 . An optional control panel  164  is illustratively coupled to the server  162 . The data memory cache  155  is for storing common data accessible by the PEDs  130  during flight of the aircraft  120 , as well as caching web pages for web browsing by a PED  130 . The data memory cache  155  also stores information during hard handoffs between base stations  140  as part of a store-and-forward capability. In addition to the cache memory  155  scheme, the server  162  includes a memory supporting a pass-through scheme, as readily appreciated by those skilled in the art. 
     The aircraft-based data traffic controller  158  is for selectively allocating data communications channel capacity between the PEDs  130  and the ground-based base stations  140 . Selectively allocating data communications channel capacity may also be alternatively or additionally performed on the ground using a ground-based data traffic controller  148  coupled to the PSTN  141  and the ISP  142 . The respective controllers  148 ,  158  control the IP traffic that will be allowed over the air-to-ground network  200 . 
     The respective controllers  148 ,  158  thus operate as filters, which may be static or dynamic. Their operation depends on whether the network  100  is lightly loaded or heavily loaded. For example, an email (from the aircraft  120 ) with a very large attachment would be limited or restricted by the aircraft-based data traffic controller  158 , whereas an Internet request resulting in a large number of web pages being sent to a PED  130  (from a ground-based base station  140 ) would be limited by the ground-based data traffic controller  148 . 
     By selectively allocating the data communications channel capacity, a greater or maximum number of passengers on the aircraft  120  can communicate over the air-to-ground interface  200  using their own PEDs  130 . For a given PED  130 , the aircraft-based data traffic controller  158  may thus limit data communications from exceeding a predetermined portion of the data communications channel capacity. 
     Allocation of the data communications channel capacity may be based on a number of different factors or metrics. For example, the respective data traffic controllers  148 ,  158  may allocate the data communications channel capacity based on a priority of service. For example, credit card information used for on-board purchases/shopping could have a higher priority over e-mail. The data communications may comprise flight operational data and non-flight operational data. Certain types of traffic may have priority over other types of traffic. Personnel having PEDs  130  include passengers, as well as other individuals supporting operation of the aircraft. Personnel with PEDs  130  supporting operation of the aircraft would be associated with flight operational data, and this may be assigned a higher priority. 
     PEDs  130  that are cellular or PCS devices and are also Wi-Fi compatible are known as dual-mode devices. One of the modes is cellular communications, with the other mode being Wi-Fi communications. Many laptop, personal computers, and PDAs are Wi-Fi/WiMax compatible, which are also classified herein as PEDs. After a connection is made to the on-board server  162  via Wi-Fi or WiMax, each PED  130  can transmit and receive emails and text messages over the air-to-ground interface  200 . 
     The dual-mode PEDs  130  carried by the passengers thus support multiple air interfaces, i.e., a terrestrial network and Wi-Fi or WiMax. Example terrestrial networks include any one of the following: 1) PCS, 2) the GSM family including EDGE, GPRS, HSDPA, HSDPA, and 3) the CDMA family including IS-95, CDMA2000, 1xRTT, EVDO. The terrestrial network may also operate based on other network interfaces standards, as will be readily appreciated by those skilled in the art. To reduce the cost of the dual-mode PEDs  130 , a software radio may be used wherein the radio is configured to the air interface standard that is available. If more than one air interface standard is available, different metrics may be evaluated to determine a preferred air interface. 
     Referring now to  FIGS. 2 and 3 , as an alternative to aircraft installed equipment, a respective translator device  50  may be used to interface between each PED  30  and a ground-based base station  40  over the air-to-ground interface  20 . The translator device  50  comprises an air-to-ground transceiver  52  with an air-to-ground antenna  54  coupled thereto. 
     In the illustrated embodiment, no additional equipment may need to be installed in the aircraft  12  since the translator devices  50  would be brought on-board by the passengers. Each translator device  50  may interface with the PED  30  via a wired or wireless connection. The wireless connection may be a Wi-Fi connection ( 802 . 11 ) or a WiMax connection ( 802 . 16 ), for example. The wired connection may be a USE interface  55 . 
     Alternatively, the translator device may be integrated directly into the PED  30 ′, as illustrated in  FIG. 3 . The PED  30 ′ would further include a controller  56 ′ for selecting between the ground-based transceiver  58 ′ or the air-to-ground transceiver  52 ′ associated with the translator. A separate antenna  59 ′ is coupled to the ground-based transceiver  58 ′. Instead of separate antennas  54 ′ and  59 ′, a shared antenna may be used. The controller  56 ′ may perform the selection automatically based on one or more monitored metrics, or the selection may be based on input from the user. 
     Referring again to  FIG. 1 , another aspect of the illustrated embodiment is directed to a method for operating a communications system  100  for an aircraft  120  carrying at least some personnel having PEDs  130  for wireless data communications outside the aircraft with a ground-based communications network. The communications system  100  includes an access point  160  in the aircraft  120  for providing a WAN for data communications with the PEDs  130 , and an air-to-ground transceiver  152  in the aircraft  120  cooperating with the access point  160  for data communications with the ground-based communications network. The method may comprise selectively allocating data communications channel capacity between the PEDs  130  and the ground-based communications network using at least one data traffic controller. The at least one data traffic controller may be an aircraft-based data traffic controller  158  and/or a ground-based data traffic controller  148 . 
     Referring now to  FIG. 4 , another aspect will be discussed with respect to the data memory cache  155  cooperating with the access point  160  for storing common data accessible by the PEDs  130  during flight of the aircraft  120 . The common data may be in the form of web pages in which passengers can browse via their PED  130 . 
     One of the functions of the data memory cache  155  is for caching predetermined web pages to be browsed. Instead of the aircraft  120  receiving the web pages while in-flight, the web pages are received while the aircraft is on the ground. Nonetheless, the web pages may be alternatively or additionally updated or refreshed while in flight. As an alternative to the data memory cache  155 , streaming video or audio could be real time or stored as provided from a satellite, including via a preexisting satellite based IFE system on the aircraft  120 . 
     The stored web pages may be directed to a particular topic or theme, such as services and products. The services may also be directed to advertisements, for example. A purchase acceptance controller  190  cooperates with the WLAN to accept a purchase from the PEDs  130  responsive to the common data related to the services and products. 
     For example, the web content may be directed to an electronic retail supplier so that any one of the passengers on-board the aircraft  120  can shop for a variety of different items using their FED  130 . Once a passenger selects an item for purchase, the transaction can be completed in real time while being airborne via the purchase acceptance controller  190  communicating over the air-to-ground link  200 . This form of on-board shopping may also be referred to as air-commerce. Alternatively, the transaction could be initiated on-board the aircraft  120  via the purchase acceptance controller  190  but the actual purchase could be forwarded via the ground data link  174  once the aircraft  120  is on the ground. 
     The data memory cache  155  may be configured to push the common data related to the services and products to the PEDs  130 . Also, the data memory cache  155  may permit the PEDs  130  to pull the common data related to the services and products therefrom. 
     In addition to products and services, the common data is directed to interactive maps, as will now be discussed in reference to  FIGS. 5 and 6 . When an interactive map is displayed on a PED  130 , the passenger is able to scroll or zoom in and out using a scroll or zoom bar  201 , as illustrated by the screen shot  203  from their PED  130 . The interactive maps preferably correspond to the flight path  203  of the aircraft  120 , and are updated or refreshed via the ground data link  174  when the aircraft  120  is parked on the ground at the airport  170 . 
     While in flight, the current location of the aircraft  120  can be displayed. Flight information  205  may also be displayed. The current location of the aircraft  120  may be provided by a position determining device/flight path determining  191 , such as a GPS system carried by the aircraft. Alternatively, the position of the aircraft  120  can be determined on the ground and passed to the aircraft over the air-to-ground link  200 . The final destination of the aircraft  120  can also be displayed prior to arrival at the destination. In addition, destination information such as the arriving gate number, connecting gate numbers, baggage claim information, hotels, rental car agencies, restaurants, etc. could also be displayed. 
     Data associated with the destination  209  may also be made available to the passengers. As illustrated by the screen shot  207  from a PED  130 , data categories titled Hotels  211 , Rental Cars  213 , Restaurants  215  and Entertainment  217  are available for viewing by the passenger. 
     If the passenger does not already have a hotel reservation, then a desired or preferred hotel associated with the destination of the aircraft  120  can be selected from the Hotels category  211 . The communications system  100  advantageously allows the passenger to make a hotel reservation while in flight. Likewise, a rental car reservation can also be made while in flight if a car is needed. Other points of interest or services (such as restaurants and entertainment) associated with the destination of the aircraft  120  can also be made available to the passengers, including reservations, coupons and other available discounts, for example. 
     Referring back to  FIG. 4 , when the aircraft  120  is parked on the ground at the airport  170 , a wireless airport data link  172  is used to transmit the web content pages to the data memory cache  155  via a ground data link receiver  174  carried by the aircraft  120 . A ground data link antenna  176  is coupled to the ground data link receiver  174 . The ground data link interface  180  may be compatible with 802.11 or 802.16, for example. The ground data link interface  180  may be Wi-Fi or WiMax for the aircraft  120 . Other interface standards may be used as will be readily appreciated by those skilled in the art. These interfaces also include cellular and PCS compatibility, for example. 
     When the aircraft  120  lands at a different airport, the web pages can be updated or refreshed over the ground data link interface  180 . In addition, email and text messaging by the PEDs  130  may be continued after the aircraft is on the ground. Since the air-to-ground interface  200  may not be available when the aircraft  120  is on the ground, the ground data link interface  180  would then be used. 
     Once the web pages are stored in the data memory cache  155 , a passenger using their Wi-Fi or WiMax enabled PED  130  can access and browse the web pages for on-board shopping while the aircraft  120  is airborne. The data memory cache  155  is sufficiently sized for storing a large amount of information, as will be readily appreciated by those skilled in the art. 
     The on-board shopping just described is for items that are not carried on the aircraft  120 . On-board shopping may also be provided to the passengers for a limited number of products. For example, when watching a movie or listening to music, passengers have the option of receiving standard headphones or they can purchase a different set of headphones, such as high quality noise suppression headphones. These transactions can also be completed via the passenger&#39;s PED  130  using the web-based pages stored in the data memory cache  155 . 
     Another aspect of the illustrated embodiment is directed to a method for operating a communications system  100  for an aircraft  120  carrying at least some personnel having personal electronic devices (PEDs) for wireless data communications outside the aircraft with a ground-based communications network. The communications system  100  may include an access point  160  in the aircraft  120  for providing a wireless local area network (WLAN) for data communications with the PEDs  130 , and an air-to-ground transceiver  152  in the aircraft  120  cooperating with the access point  160  for data communications with the ground-based communications network. The method may comprise storing common data accessible by the PEDs  130  during flight of the aircraft  120  using an aircraft data memory cache  155  in the aircraft and cooperating with the access point  160 . 
     The PEDs  130  are not limited to receiving and transmitting information over the air-to-ground interface  200 . Referring now to  FIG. 7 , signals may be transmitted from satellites  220 ,  230  to a multi-beam satellite antenna  240  coupled to a satellite receiver  242  carried by the aircraft  120 . This is in addition to transmitting and receiving signals over the air-to-ground interface  200  via the ground-based network and the air-to-ground transceiver  152  carried by the aircraft  120 . 
     In the illustrated embodiment, an aircraft-based network selection controller  192  is associated with the air-to-ground transceiver  152  and the access points  160 . The aircraft-based network selection controller  192  determines whether data communications should be sent to the PEDs  130  through the air-to-ground transceiver  152  or the satellite receiver  242 . This is accomplished by appending data to return via a satellite. 
     In addition or in lieu of the aircraft-based network selection controller  192 , a ground-based network selection controller  194  is coupled between a ground-based satellite transmitter  145  and the ground-based base stations  140 . The ground-based network selection controller  194  also determines whether to send data communications to the PEDs  130  through the air-to-ground transceiver  152  or through the satellite receiver  242 . 
     Satellite  220  provides television and digital radio signals for an in-flight entertainment (IFE) system on the aircraft  120  over satellite link  254 . Even though only one satellite is represented, the television and digital radio signals may be provided by separate satellites, such as a DirectTV™ satellite and an XM™ radio satellite. In addition, a third satellite may be used to provide email and text messaging, multimedia messaging, credit card transactions, web surfing, etc. The illustrated satellite antenna  240  supports communications with all three satellites, i.e., the DirectTV™ satellite, the XM™ radio satellite, and the email-text messaging satellite. 
     An example IFE system is disclosed in U.S. Pat. No. 7,748,597. This patent is assigned to the current assignee of the present invention, and is incorporated herein by reference in its entirety. The television and digital radio signals are sent through the on-board server  162  to seat electronic boxes (SEBs) spaced throughout the aircraft for selective viewing on video display units (VDUs). Passenger control units (PCUs) are used to control the VDUs. The digital radio signals are also distributed to the SEES for reception via passenger headphones. 
     Of particular interest is that additional information can be obtained from the satellite  220  which can then be made available to the PEDs  130 . For example, the satellite  220  may provide information including sports scores, stock ticker, news headlines, destination weather and destination traffic. The satellite signals received by the satellite receiver  242  are provided to the on-board server  162  for repackaging this particular information for presentation to the PEDs  130  via the access points  160 , as will be readily appreciated by those skilled in the art. 
     When available, satellites with or without leased transponders may also provide additional information to be repackaged by the on-board server  162 . The other satellite  230  may be a fixed satellite service (FSS) for providing Internet access to the PEDs  130 , for example. For example, satellite television and satellite radio signals may be provided to the passengers on their PEDs  130  via Wi-Fi. 
     In this configuration, a message for web pages requested by the passenger (via their PED  130 ) is provided over the air-to-ground interface  200 . The message on the ground would then be routed to an appropriate ground-based network selection controller  194 , which would then transmit the request to the FSS satellite  230 . The satellite link between the appropriate ground-based transmitter  145  and the satellite  230  is represented by reference  250 . The FSS satellite  230  then transmits the requested web pages to the aircraft  120  over satellite link  252  upon receiving the request from the ground. 
     Since the satellites may be somewhat close together in a geospatial arc, transmitting the return link over the air-to-ground link  200  instead of over the satellite links  252 ,  254  avoids causing interference from the aircraft  120  to neighboring satellites. Nonetheless, the request could be transmitted directly from the aircraft  120  to the satellite  230  using a steerable or directional satellite antenna. 
     The request provided by the PED  130  is often referred to as the return link. The information from the satellites  220 ,  230  to the aircraft  120  is often referred to as the forward link. The air-to-ground interface  200  is a narrow band interface, which is acceptable for making a request since such a request is typically narrower band than the forward link. In contrast, satellite links  252  and  254  are wide band interfaces, which are ideal form providing the requested web pages that are typically wide band data. 
     Each of the network selection controllers  192 ,  194  may be used to determine whether to send data communications to the PEDs  130  through the air-to-ground transceiver  152  or the satellite receiver  242  based on a needed channel capacity of the data communications to be sent or congestion on a link. Data communications with a higher needed channel capacity is typically sent with a high bandwidth using the satellite receiver  242 , and data communications with a lower needed channel capacity is typically sent with a low bandwidth using the air-to-ground transceiver  152 . Alternatively, the high and low broadband data communications links may be reversed. Alternatively, the network controllers could determine that the aircraft  120  is out of the coverage area for the air-to-ground network or the air-to-ground network is at capacity in the location for that aircraft. In this case, the network selection controllers could route the traffic over the satellite network. Alternatively, the network selection controllers could route some traffic types over one network and other traffic types over the other network, as readily appreciated by those skilled in the art. 
     One of the network selection controllers  192 ,  194  may determine to send data communications to the PEDs  130  through the air-to-ground transceiver  152  or through the satellite receiver  242  based on received signal strength of the data communications, or a position of the aircraft. The current location of the aircraft  120  may be provided by a position determining device/flight path determining  191 , such as a GPS system carried by the aircraft. Alternatively, the position of the aircraft  120  can be determined on the ground and passed to the aircraft over the air-to-ground link  200 . If the aircraft  120  is to fly over the ocean, then data should be received through the satellite receiver  242 . By monitoring signal strength of the received signals or the position of the aircraft, a determination can be made on when the ground-based base stations  140  are no longer available, and communications should be received via the satellite receiver  242 . 
     The network selection controllers  192 ,  194  thus determine whether to send static and dynamic web pages through the satellite-based communications network  145 ,  230  to the PEDs  130 . Dynamic web pages include streaming video, for example. Each network selection controller  192 ,  194  may determine to send requests for at least one of the static and dynamic web pages from the PEDs  130  through the access points  160  and the air-to-ground transceiver  152 . 
     As noted above, predetermined web pages are stored in the data memory cache  155  when the aircraft  120  is parked on the ground (i.e., electronic retailer shopping and on-board shopping, as well as advertisements). Since the satellite links  252 ,  254  are wide band, the requested web information may also be downloaded for storage or refreshed in the data memory cache  155  while the aircraft is in flight. 
     Another aspect of the illustrated embodiment is directed to a method for operating a communications system  100  for an aircraft  120  carrying at least some personnel having personal electronic devices (PEDs)  130  for wireless data communications outside the aircraft. The communications system  100  includes a ground-based communications network, a satellite-based communications network, and at least one access point  160  in the aircraft  120  for providing a WLAN for data communications with the PEDs  130 . An air-to-ground transceiver  154  in the aircraft  120  may cooperate with the at least one access point  160  for data communications with the ground-based communications network, and a satellite receiver  242  in the aircraft may cooperate with the at least one access point for data communications with the satellite-based communications network to the PEDs. The method includes determining whether to send data communications to the PEDs  130  through the air-to-ground transceiver  152  or the satellite receiver  242 . 
     Referring now to  FIG. 8 , another aspect is directed to handoff of the aircraft  120  from one ground-based base station  140  to an adjacent ground-based base station, or between azimuth or elevation sectors on one base station. Since the air-to-ground network  100  may be optimized for data instead of voice, delays or latencies can be tolerated without the end user having the perception that the call is being dropped as is the case with voice. Consequently, soft handoffs are needed for voice-based networks. 
     In contrast, data can be stored on the ground or on the aircraft while the aircraft  120  is between cell coverage areas for a hard handoff. Once the aircraft  120  is within coverage of the next cell, the data can then be forwarded. 
     Hard handoffs can thus be used to make the connection from one base station  140  to an adjacent base station in support of the air-to-ground communications network  100 . Messages being communicated between a PED  130  and the ground can be stored in a buffer or memory  157 . The buffer  157  may be part of the data memory cache  155 , or alternatively, the buffer may be a separate memory as illustrated. Each base station  140  has a hard handoff controller  147  associated therewith. Moreover, with the aircraft  120  typically flying at speeds over 500 mph, the delay is relatively short. 
     To support a soft handoff, as would be necessary with voice, twice the spectrum resources would be needed. With a hard handoff, the spectrum is preserved at the expense of having sufficient memory for storing data in the buffer  157  (or on the ground) during a handoff while the aircraft  120  is between base stations  140 . 
     The base stations  140  define respective adjacent coverage areas and comprise respective hard handoff controllers  147  for implementing a hard handoff of a data communications channel with the air-to-ground transceiver  152  as the aircraft  120  moves from one coverage area to an adjacent coverage area. 
     An aircraft hard handoff controller  149  may cooperate with the hard handoff controllers  147  on the ground. The aircraft hard handoff controller  149  cooperates with ground-based hard handoff controllers  147  by monitoring metrics. The metrics include a received signal strength of the data communications channel, or available capacity at the base station  140 , for example. 
     In another embodiment for implementing an aircraft hard handoff, the aircraft hard handoff controller  149  implements the hard handoff of a data communications channel with the air-to-ground transceiver  152  as the aircraft  120  moves from one coverage area to an adjacent coverage area. This implementation may be based on metrics collected in the aircraft. These metrics include a Doppler shift of the data communications channel, a signal-to-noise ratio of the data communications channel, or a received signal strength of the data communications channel. This implementation may also be based on position of the aircraft  120 , as readily appreciated by those skilled in the art. 
     The buffer  157  may be separate from the aircraft hard handoff controller  149  or may be integrated as par the hard handoff controller. The first and second hard handoff controllers  147  may implement the hard handoff based on the following metrics: a Doppler shift of the data communications channel, a signal-to-noise ratio of the data communications channel, or a received signal strength of the data communications channel, as will be readily appreciated by those skilled in the art. 
     In other embodiments, a position/flight determining device  191  on the aircraft  120  cooperates with the ground-based hard handoff controllers  147  for implementing the hard handoff based upon a position of the aircraft. The position/flight path determining device  191  may be a GPS or other navigational device. 
     The base stations  140  may be configured with selectable antenna beams for performing the hard handoff, as will now be discussed. In one embodiment, one or more of the base stations  140  include selectable antenna beams  97 , with each antenna beam having a same pattern and gain but in a different sector as compared to the other antenna beams. The different sector may also be defined in azimuth and/or elevation. Each antenna beam  97  may be optimized in terms of gain and beam width. The minimally overlapping antenna beams  97  thus provide complete coverage in the different sectors. 
     In another embodiment, one or more of the base stations  140  include selectable antenna beams  98  and  99 , with at least two antenna beams being in a same sector but with a different pattern and gain. Antenna beam  99  is high gain with a narrow beam width for communicating with the aircraft  120  at an extended distance from the base station  140 . When the aircraft  120  is closer in range to the base station  140 , antenna beam  98  is selected, which is low gain with a wide beam width. 
     As noted above, there are a number of different metrics to monitor to determine when airborne users (i.e., PEDs  130 ) within an aircraft  120  are to be handed off to a next base station  140 . In terms of Doppler, the Doppler shift on the MAC addresses of the signals received by each base station  140  are examined. The Doppler metric is to be factored into the handoff algorithm at each base station  140 . 
     When using GPS coordinates, each base station  140  receives GPS coordinates of the aircraft  120 , and based upon movement of the aircraft, the base stations coordinate handoff of the aircraft accordingly from base station to base station. 
     Along the same lines, sectorized antennas at the base station  140  may be used for communicating with the aircraft  120 . The antennas at each base station  140  may provide a high gain/narrow beamwidth coverage sector and a low gain/broad beamwidth coverage sector. The high gain/narrow beamwidth coverage sector may be used when link conditions with the aircraft  120  are poor. Sites could be sectorized in azimuth, elevation or both. These sectors could be static or dynamic. 
     If the link conditions with the aircraft  120  are good, then the low gain/broad beamwidth coverage beam is used. In one embodiment, the coverage sectors are selected based upon the link conditions with the aircraft  120 . Alternatively, the coverage sectors are fixed at the base station  140 . For example, the high gain/narrow beamwidth coverage sector may be used for aircraft  120  that are farther away from the base station  140 , whereas the low gain/broad beamwidth coverage sector may be used for aircraft flying near the base station. 
     Lastly, a ground selection algorithm may be used to select a ground-based base station  140  based on the flight path and the base stations in proximity to the flight path. If the aircraft  120  is about to exit a cell, transmitted email and text messages for a PED  130  are stored until the aircraft is in the next coverage area. This advantageously allows a longer continuous connection, which makes use of the limited spectrum resources more efficiently. The ground selection algorithm could use ground-based location information or GPS data on the location of the aircraft  120  and known ground site locations to optimize connection times. The resulting system may thus be considered a store-and-forward architecture. 
     Another aspect of the illustrated embodiment is directed to a method for operating a communications system  100  for an aircraft  120  carrying at least some personnel having personal electronic devices (PEDs)  130  for wireless data communications outside the aircraft with a ground-based communications network. The communications system  100  includes a plurality of spaced apart base stations  140 , and at least one access point  160  in the aircraft  120  for providing a wireless local area network (WLAN) for data communications with the PEDs  130 . An air-to-ground transceiver  152  in the aircraft  120  may cooperate with the at least one access point  160  for data communications with the ground-based communications network. The method may include operating first and second base stations  140  to define respective first and second adjacent coverage areas, with the first and second base stations comprising respective first and second hard handoff controllers  147 . The respective first and second hard handoff controllers  147  are operated for implementing a hard handoff of a data communications channel with the air-to-ground transceiver  152  as the aircraft  120  moves from the first coverage area to the second adjacent coverage area. Alternatively, the handoff decision can be implemented by an aircraft hard handoff controller  149  in the aircraft  120 . This implementation may be based on metrics collected in the aircraft  120 . 
     To summarize example on-board content deliveries to the aircraft  120  from the various sources, reference is directed to  FIG. 9 . When in flight, the air-to-ground interface  200  provides connectivity for features that include email, text messaging, credit card transactions, multimedia messaging, web surfing and RSS as indicated by reference  300 . To use RSS, the PED  130  has an RSS news reader or aggregator that allows the collection and display of RSS feeds. RSS news readers allow a passenger to view the service selected in one place and, by automatically retrieving updates, stay current with new content soon after it is published. There are many readers available and most are free. 
     The airport data link  172  may be used to provide the best of YouTube™ as indicated by reference  302 . The XM™ satellite  220  may provide sports scores, stock ticker, news headlines and destination traffic as indicated by reference  304 . DirectTV™ may also be provided by satellite  220  which can be used to provide additional information as indicated by reference  306 . For future growth, two-way communications may be provided by a satellite as indicated by reference  308 , such as with DirecWay or Hughesnet, for example. The airport data link  172  may also be used to provide cellular/PCS/WiMax services as indicated by reference  310 . 
     The above content is provided to the on-board server  162  which may include or interface with the data memory cache  155 . The data is provided to passenger PEDs  130  using Wi-Fi or WiMax distribution via the access points  160 . Video and data is provided to an Ethernet distribution  320  for distributing throughout the aircraft as part of the in-flight entertainment system. 
     In terms of transmission distance or proximity to the aircraft  120  for the above-described on-board content deliveries, reference is directed to  FIG. 10 . Circle  350  represents information provided by the airport ground data link  172  when the aircraft  120  is parked at the airport  170  or moving about the airport with weight on wheels. When airborne, circle  352  represents information provided via the air-to-ground interface  200 , and circle  354  represents the information provided by the satellites  220 ,  230 . The information as discussed above is summarized in the respective circles  350 ,  352  and  354 . 
     In view of the different air interface standards associated with the aircraft  120 , the on-board server  162  may be configured to recognize the available air interface standards. As a result, the on-board server  162  selects the appropriate air interface standard based on proximity to a particular network. This decision may also be based on the bandwidth that is available, location of the aircraft  120  as determined by GPS, and whether the aircraft is taking off or landing. For example, when the aircraft  120  is on the ground, the ground data link interface  180  is selected. When airborne, the network selection controllers  192 ,  194  select either the air-to-ground interface  200  or a satellite interface  252 ,  254  depending on traffic demands, or both, for example. 
     Depending on the airline rules and regulations, the cellular mode of a dual mode cellular/Wi-Fi device may not be operated on an aircraft below a certain altitude, such as 10,000 feet. To support this requirement, the on-board server  162  and the Wi-Fi access points  160  may have enough pico-cell capability to drive the cellular radio in dual mode devices to minimum power or even to turn the cellular radios off. The connection to the wireless onboard network could be WiFi or WiMax. The Pico-cell function would be to drive cellular/PCS output power to a reduced/minimum or off condition. This turns the cellular/PCS transmitter “off” while on the aircraft, while allowing Wi-Fi transmission and reception. 
     Another metric to monitor on the aircraft  120  is related to priority of service. This is due to the fact that that aircraft  120  can receive information over a wide band link from a satellite, for example, and transmit requests for the information over a narrow band link. If someone tries to send a large attachment on their email over the narrow band link, or they are video/audio streaming, then access will be denied or throttled or charged for a premium service for large data transfers by the data traffic controllers  158 ,  148 . It could also be possible to use pico-cells to connect cellular/PCS mobile phones (FED)  130  to the onboard systems. 
     Therefore, traffic is monitored in terms of metrics to make quality of service and priority of service decisions. This decision may be made on-board the aircraft  120  for any traffic leaving the aircraft  120 . This decision may also be made on the ground, which monitors if someone on the ground is sending to large of an attachment, and if so, then access will also be denied or throttled or charged for a premium service for large data transfers. These criteria for decisions could by dynamic or static. 
     Priority of service also relates to quality of service. Various metrics and traffic conditions can be monitored to provide connectivity to a greater or maximum number of airline passengers on a flight. Operations and cabin passenger entertainment (email, text messaging, web browsing, etc.) data can be multiplexed on a variable latency link. Operational and passenger data may also be multiplexed with multiple priorities of service allowing some data to be handled at a higher priority than other data. 
     Yet another aspect of the aircraft air-to-ground communications network  10  is with respect to advertisements. The advertisements are used to generate revenue from the air to ground, hybrid air to ground/satellite, or satellite communications network. For example, when a passenger opens up their laptop computer  130  on the aircraft  120 , a decision is made whether or not to use the 802.11 Wi-Fi or 802.16 WiMax network. If the decision is yes, then an advertisement is displayed while accessing the network. 
     In addition, when portal pages are viewed, advertisements will also be displayed. Since the advertisements are used to generate revenues, passengers are allowed access to the air-to-ground communications network  100  without having to pay with a credit card or touchless payment method, as was the case for the Connexion by Boeing SM  system. While looking at different web pages, the passengers will see advertisements interspersed or sharing the same screen. 
     Another function of the aircraft  120  is to use the air-to-ground communications network  100  for telemetry. Telemetry involves collecting data at remote locations, and then transmitting the data to a central station. The problem arises when the data collection devices at the remote locations are separated beyond line-of-sight from the central station. Consequently, one or more towers are required to complete the telemetry link. To avoid the costly expense of providing telemetry towers, the aircraft  120  may be used to relay the collected information from the remote locations to the central station when flying overhead. 
     Yet another function of the aircraft  120  is to use the air-to-ground communications network  100  for ground-based RFID tracking. Similar to using the aircraft  120  for telemetry, the aircraft may also be used for tracking mobile assets on the ground, such as a fleet of trucks, for example. The trucks transmit RFID signals that are received by the aircraft  120  as it flies overhead. The information is then relayed to a central station. The RFID signals may be GPS coordinates, for example. 
     Another aspect of the air-to-ground communications network  100  is to provide video on demand on the aircraft  120 . This feature has been partially discussed above and involves providing television signals on demand to passengers on the aircraft. The television signals may be terrestrial based or relayed via a satellite, In particular, the return to make the request is not the same as the forward link providing the video. The return link is a low data rate link, and may be provided by the aircraft passenger&#39;s PED  130  over the air-to-ground interface  200 . The forward link is a high data rate link received by a terrestrial or satellite based receiver on the aircraft, The video is then routed through the aircraft in-flight entertainment system to the passenger, or to the passenger&#39;s PED  130  via Wi-Fi. Alternatively, the video or audio can be stored in the server  162  and displayed when requested by a passenger. 
     The major components of an in-flight entertainment system  430  will now be discussed with reference to  FIGS. 11 through 13 . In particular, the illustrated system  430  is discussed with respect to a television programming distribution system. For discussion purposes, the illustrated system  430  does not include the access points  160  as discussed above. 
     The in-flight entertainment system  430  includes a satellite antenna system  435  to be mounted on the fuselage  432  of the aircraft  431 . The satellite antenna system  435  supports reception of television programming and Internet data from separate satellites, as will be discussed in greater below. However, for discussion purposes, reception will be focused on receiving the television programming from the illustrated DES satellite  433 . 
     The system  430  includes one or more multi-channel receiver modulators (MRMs)  440 , a cable distribution network  441 , a plurality of seat electronic boxes (SEBs)  445  spaced about the aircraft cabin, and video display units (VDUs)  447  for the passengers and which are connected to the SEBs. In the illustrated embodiment, the system  430  receives, distributes, and decodes the DBS transmissions from the DBS satellite  433 . In other embodiments, the system  430  may receive video or TV signals from other classes of satellites as will be readily appreciated by those skilled in the art, including Internet Data from an FSS satellite. 
     The satellite antenna system  435  delivers DES signals to the MRMs  440  for processing. For example, each MRM  440  may include twelve DBS receivers and twelve video/audio RF modulators. The twelve receivers recover the digitally encoded multiplexed data for twelve television programs as will be appreciated by those skilled in the art. 
     As shown in the more detailed schematic diagram of  FIGS. 12A and 12B , an audio video modulator (AVM)  450  is connected to the MRMs  440 , as well as a number of other inputs and outputs. The AVM  450  illustratively receives inputs from an external camera  452 , as well as one or more other video sources  454 , such as videotape sources, and receives signal inputs from one or more audio sources  456  which may also be prerecorded, for example. A PA keyline input and PA audio input are provided for passenger address and video address override. Audio for any receiver along with an associated keyline are provided as outputs from the MRM  440  so that the audio may be broadcast over the cabin speaker system, for example, as will also be appreciated by those skilled in the art. In the illustrated embodiment, a control panel  451  is provided as part of the AVM  450 . The control panel  451  not only permits control of the system, but also displays pertinent system information and permits various diagnostic or maintenance activities to be quickly and easily performed. 
     The AVM  450  is also illustratively coupled to a ground data link radio transceiver  457 , such as for permitting downloading or uploading of data or programming information. The AVM  450  is also illustratively interfaced to an air-to-ground telephone system  458  as will be appreciated by those skilled in the art. 
     The AVM  450  illustratively generates a number of NTSC video outputs which may be fed to one or more retractable monitors  461  spaced throughout the cabin. Power is preferably provided by the aircraft 400 Hz AC power supply as will also be appreciated by those skilled in the art. Of course, in some embodiments, the retractable monitors may not be needed. 
     The MRMs  440  may perform system control, and status monitoring. An RF distribution assembly (RDA)  462  can be provided to combine signals from a number of MRMs, such as four, for example. The RDA  462  combines the MRM RF outputs to create a single RF signal comprising up to 48 audio/video channels, for example. The RDA  462  amplifies and distributes the composite RF signal to a predetermined number of zone cable outputs. Eight zones are typical for a typical narrow-body single-aisle aircraft  431 . Depending on the aircraft, not all eight outputs may be used. Each cable will serve a zone of seatgroups  465  in the passenger cabin. 
     Referring now more specifically to the lower portion of  FIG. 12B  and also to  FIG. 13 , distribution of the RF signals and display of video to the passengers is now further described. Each zone cable  441  feeds the RF signal to a group of contiguous seatgroups  465  along either the right or left hand side of the passenger aisle. In the illustrated embodiment, the seatgroup  465  includes three side-by-side seats  466 , although this number may also be two for other types of conventional narrow-body aircraft. 
     The distribution cables  441  are connected to the first SEB  445  in each respective right or left zone. The other SEBs  445  are daisy-chained together with seat-to-seat cables. The zone feed, and seat-to-seat cables preferably comprise an RF audio-video coaxial cable, a 400 Hz cycle power cable, and RS 485 data wiring. 
     For each seat  466  in the group  465 , the SEE  445  tunes to and demodulates one of the RF modulated audio/video channels. The audio and video are output to the passenger video display units (VDUs)  468  and headphones  470 , respectively. The tuner channels are under control of the passenger control unit (PCU)  471 , typically mounted in the armrest of the seat  466 , and which also carries a volume control. 
     Each VDU  468  may be a flat panel color display mounted in the seatback. The VDU  468  may also be mounted in the aircraft bulkhead in other configurations as will be appreciated by those skilled in the art. The VDU  468  will also typically include associated therewith a user payment card reader  472 . The payment card reader  472  may be a credit card reader, for example, of the type that reads magnetically encoded information from a stripe carried by the card as the user swipes the card through a slot in the reader as will be appreciated by those skilled in the art. In some embodiments, the credit card data may be processed on the aircraft to make certain processing decisions relating to validity, such as whether the card is expired, for example. As described in greater detail below, the payment card reader  472  may also be used as the single input required to activate the system for enhanced user convenience. 
     The cable distribution system is modeled after a conventional ground based cable TV system in terms of signal modulation, cabling, drops, etc. Certain changes are made to allocate the available channels, such as forty-eight, so as not to cause potential interference problems with other equipment aboard the aircraft  431  as will be appreciated by those skilled in the art. In addition, there are basically no active components along the cable distribution path that may fail, for example. The cable distribution system also includes zones of seatgroups  466 . The zones provide greater robustness in the event of a failure. The zones can also be added, such as to provide full service throughout the cabin. 
     At least one entertainment source is installed on the aircraft. The entertainment source may include a satellite TV source, such as provided by the DES antenna system  435  and MRMs  440  described above. A plurality of spaced apart signal distribution devices is installed, each generating audio signals for at least one passenger in an audio-only mode, and generating audio and video signals to at least one passenger in an audio/video mode. These devices may be the SEBs  445  described above as will be readily appreciated by those skilled in the art. 
     The cable network is installed on the aircraft  431  connecting the at least one entertainment source to the signal distribution devices. In other words, the MRMs  440  are connected to the SEEs  445  in the various equipped zones throughout the aircraft  431 . 
     Turning now additionally to  FIGS. 14 and 15 , advantages and features of the satellite antenna system  435  are now described in greater detail. The satellite antenna system  435  includes an antenna  536  which may be positioned or steered by one or more antenna positioners  538  as will be appreciated by those skilled in the art. In addition, one or more position encoders  541  may also be associated with the antenna  536  to steer the antenna to thereby track the DES satellite or satellites  533 . Of course, a positioning motor and associated encoder may be provided together within a common housing, as will also be appreciated by those skilled in the art. In accordance with one significant advantage, the antenna  536  may be steered using received signals in the relatively wide bandwidth of at least one DES transponder. 
     More particularly, the satellite antenna system  435  includes an antenna steering controller  542 , which, in turn, comprises the illustrated full transponder bandwidth received signal detector  543 . This detector  543  generates a received signal strength feedback signal based upon signals received from the full bandwidth of a DBS transponder rather than a single demodulated programming channel, for example. Of course, in other embodiments the same principles can be employed for other classes or types of satellites than the DBS satellites described herein by way of example, such as for receiving Internet data from an FSS satellite. In addition, the detector could operate on a portion of the transponder bandwidth but not the full transponder bandwidth. 
     In the illustrated embodiment, the detector  543  is coupled to the output of the illustrated intermediate frequency interface (IFI)  546  which converts the received signals to one or more intermediate frequencies for further processing by the MRMs  440  as described above and as will be readily appreciated by those skilled in the art. In other embodiments, signal processing circuitry, other than that in the IFI  546  may also be used to couple the received signal from one or more full satellite transponders to the received signal strength detector  543  as will also be appreciated by those skilled in the art. 
     A processor  545  is illustratively connected to the received signal strength detector  543  for controlling the antenna steering positioners  538  during aircraft flight and based upon the received signal strength feedback signal. Accordingly, tracking of the satellite or satellites  433  is enhanced and signal service reliability is also enhanced. 
     The antenna steering controller  542  may further comprise at least one inertial rate sensor  548  as shown in the illustrated embodiment, such as for roll, pitch or yaw as will be appreciated by those skilled in the art. The rate sensor  548  may be provided by one or more solid-state gyroscopes, for example. The processor  545  may calibrate the rate sensor  548  based upon the received signal strength feedback signal. 
     The illustrated satellite antenna system  435  also includes a global positioning system (GPS) antenna  551  to be carried by the aircraft fuselage  432 . This may preferably be provided as part of an antenna assembly package to be mounted on the upper portion of the fuselage. The antenna assembly may also include a suitable radome, not shown, as will be appreciated by those skilled in the art. The antenna steering controller  542  also illustratively includes a GPS receiver  552  connected to the processor  545 . The processor  545  may further calibrate the rate sensor  548  based upon signals from the GPS receiver as will be appreciated by those skilled in the art. 
     As will also be appreciated by those skilled in the art, the processor  545  may be a commercially available microprocessor operating under stored program control. Alternately, discrete logic and other signal processing circuits may be used for the processor  545 . This is also the case for the other portions or circuit components described as a processor herein as will be appreciated by those skilled in the art. The advantageous feature of this aspect is that the full or substantially full bandwidth of the satellite transponder signal is processed for determining the received signal strength, and this provides greater reliability and accuracy for steering the antenna  536 . 
     Another advantage of the antenna system  435  is that it may operate independently of the aircraft navigation system  553  which is schematically illustrated in the lower right hand portion of  FIG. 14 . In other words, the aircraft  431  may include an aircraft navigation system  553 , and the antenna steering controller  542  may operate independently of this aircraft navigation system. Thus, the antenna steering may operate faster and without potential unwanted effects on the aircraft navigation system  553  as will be appreciated by those skilled in the art. In addition, the satellite antenna system  435  is also particularly advantageous for a single-aisle narrow-body aircraft  431  where cost effectiveness and low weight are especially important. 
     Turning now additionally to  FIG. 16 , another embodiment of the satellite antenna system  435 ′ is now described which includes yet further advantageous features. This embodiment is directed to functioning in conjunction with the three essentially collocated geostationary satellites for the DIRECTV® DBS service, although the satellite antenna system  35 ′ is applicable in other situations as well. For example, the DIRECTV® satellites may be positioned above the earth at 101 degrees west longitude and spaced 0.5 degrees from each other. Of course, these DIRECTV® satellites may also be moved from these example locations, and more than three satellites may be so collocated. Considered in somewhat broader terms, these features are directed to two or more essentially collocated geostationary satellites. Different circular polarizations are implemented for reused frequencies as will be appreciated by those skilled in the art. 
     In this illustrated embodiment, the satellite antenna  536 ′ is a multi-beam antenna having an antenna boresight (indicated by reference B), and also defining right-hand circularly polarized (RHCP) and left-hand circularly polarized (LHCP) beams (designated RHCP and LHCP in  FIG. 16 ) which are offset from the antenna boresight. Moreover, the beams RHCP, LHCP are offset from one another by a beam offset angle α which is greatly exaggerated in the figure for clarity. This beam offset angle α is less than the angle β defined by the spacing defined by the satellites  433   a ,  433   b . The transponder or satellite spacing angle β is about 0.5 degrees, and the beam offset angle α is preferably less than 0.5 degrees, and may be about 0.2 degrees, for example. 
     The beam offset angle provides a squinting effect and which allows the antenna  536 ′ to be made longer and thinner than would otherwise be required, and the resulting shape is highly desirable for aircraft mounting as will be appreciated by those skilled in the art. The squinting also allows the antenna to be constructed to have additional signal margin when operating in rain, for example, as will also be appreciated by those skilled in the art. 
     The multi-beam antenna  536 ′ may be readily constructed in a phased array form or in a mechanical form as will be appreciated by those skilled in the art without requiring further discussion herein. Aspects of similar antennas are disclosed in U.S. Pat. No. 4,604,624 to Amitay et al.; U.S. Pat. No. 5,617,108 to Silinsky et al.; and U.S. Pat. No. 4,413,263 also to Amitay et al.; the entire disclosures of which are incorporated herein by reference. 
     The processor  545 ′ preferably steers the antenna  536 ′ based upon received signals from at least one of the RHCP and LHCP beams which are processed via the IFI  546 ′ and input into respective received signal strength detectors  543   a ,  543   b  of the antenna steering controller  542 ′. In one embodiment, the processor  545 ′ steers the multi-beam antenna  536 ′ based on a selected master one of the RHCP and LHCP beams and slaves the other beam therefrom. 
     In another embodiment, the processor  545 ′ steers the multi-beam antenna  536 ′ based on a predetermined contribution from each of the RHCP and LHCP beams. For example, the contribution may be the same for each beam. In other words, the steering or tracking may be such as to average the received signal strengths from each beam as will be appreciated by those skilled in the art. As will also be appreciated by those skilled in the art, other fractions or percentages can also be used. Of course, the advantage of receiving signals from two different satellites  433   a ,  433   b  is that more programming channels may then be made available to the passengers. 
     The antenna system  435 ′ may also advantageously operate independent of the aircraft navigation system  553 ′. The other elements of  FIG. 16  are indicated by prime notation and are similar to those described above with respect to  FIG. 14 . Accordingly, these similar elements need no further discussion. 
     Another aspect relates to the inclusion of adaptive polarization techniques which may be used to avoid interference from other satellites. In particular, low earth orbit satellites (LEOS) are planned which may periodically be in position to cause interference with the signal reception by the in-flight entertainment system  430 . Adaptive polarization techniques would also be desirable should assigned orbital slots for satellites be moved closer together. 
     Accordingly, the processor  545 ′ may preferably be configured to perform adaptive polarization techniques to avoid or reduce the impact of such potential interference. Other adaptive polarization techniques may also be used. Suitable adaptive polarization techniques are disclosed, for example, in U.S. Pat. No. 5,027,124 to Fitzsimmons et al; U.S. Pat. No. 5,649,318 to Lusignan; and U.S. Pat. No. 5,309,167 to Cluniat et al. The entire disclosures of each of these patents is incorporated herein by reference. Those of skill in the art will readily appreciate the implementation of such adaptive polarization techniques with the in-flight entertainment system  430  without further discussion. 
     A multi-beam phased array antenna  635  and control circuitry  640  associated therewith for simultaneously communicating with two different satellites  220 ,  230  will now be discussed in reference to  FIGS. 17-22 . Satellite  220  may be a direct broadcast satellite (DES) for providing television programming (i.e., satellite TV) to the aircraft  120 , and satellite  230  may be a fixed satellite service (FSS) for providing Internet data (i.e., satellite Internet) to the aircraft  120 . The illustrated link  254  between the DBS satellite  220  and the aircraft  120  is receive only, whereas the illustrated link  252  between the FSS satellite  230  and the aircraft is transmit and receive. 
     Both of these satellites  220 ,  230  are geosynchronous earth orbit (GEG) satellites that are separated along an equatorial arc around the earth. 
     The satellites  220 ,  230  may be at the same orbital slot assignment or at two distinctly different slot assignments. The multi-beam phased array antenna  635  and control circuitry  640  simultaneously generates dual antenna beams  650  and  660 , with each antenna beam having a respective antenna beam boresight. Alternatively, the dual antenna beams  650  and  660  may be directed at the same satellite if the satellite is a combined DBS/FSS satellite. 
     A radome  637  protects the phased array antenna  635 . In addition, the radome  637  is tuned to reduce RF signal degradation, specifically scattering loss and polarization degradation. The tuning is based on the operating frequencies of the phased array antenna  635  and the range of expected incidence angles, as will be readily appreciated by those skilled in the art. 
     A satellite transceiver  242  coupled to the phased array antenna  635  and to the control circuitry  640  is configured to simultaneously receive the television programming from the DBS satellite  220  and transmit/receive the Internet data to/from the FSS satellite  230 . Although not illustrated, the satellite transceiver  242  includes a receiver for the television programming, and a receiver (e.g., a modem) for the Internet data. The receivers may correspond to the MRMs  440  illustrated in  FIG. 14 . 
     Intermediate frequency interfaces (IFI)  546  as also illustrated in  FIG. 14  may be used to convert the received satellite signals to one or more intermediate frequencies for further processing by the MRMs  440 . The IFIs  546  thus translate the received modulated signals in frequency and perform amplification. For the transmitter portion of the satellite transceiver  242 , a transmitter provides the modulated signals to a block up converter (BUC) within the transmit signal path. The BUC performs an up-conversion and amplification of the modulated signals to be transmitted by the phased array antenna  235  and control circuitry  640 . 
     The link  252  between the FSS satellite  230  and the aircraft  120  may be used as an uplink for requesting the Internet data directly from the FSS satellite. Alternatively, the request for the Internet data may be made over the air-to-ground interface  200  as discussed above with respect to the network selection controller  192 , which is then relayed to the FSS satellite  230 . 
     A server  162  is connected to the satellite transceiver  242 . The server  162  includes a data memory cache  155  and a data traffic controller  158 . An air-to-ground antenna  154  is coupled to the air-to-ground transceiver  152 , which is also connected to the server  162 . An optional control panel  164  is illustratively coupled to the server  162 . 
     A television programming distribution system is coupled to the phased array antenna  635  and control circuitry  640  via the server  162  to provide television programming within the aircraft  120 . The television programming distribution system includes cabling  670  and at least one display  672  coupled thereto. Alternatively, the television programming distribution system may include SEBs  445  and VDUs  447  spaced throughout the cabin area of the aircraft  231  as illustrated in  FIG. 17 . Access points  160  are also coupled to the phased array antenna  635  and control circuitry  640  via the server  162  to provide a WEAN within the aircraft  120  for the Internet data. 
     The phased array antenna  635  has been divided into 8 array segments or sub-arrays  738 ( 1 )- 738 ( 8 ), as illustrated in  FIG. 18 . The actual number of sub-arrays can vary as readily appreciated by those skilled in the art. The outputs of the sub-arrays  738 ( 1 )- 738 ( 8 ) are provided to corresponding signal splitters  760 ( 1 )- 760 ( 8 ) within the control circuitry  640 . A respective sub-array and signal splitter will be generally referred to by references  738  and  760 . 
     The television programming may be receive only from the DES satellite  220 , whereas the Internet data may be transmit and receive with respect to the FSS satellite  230 . For the receive side of the phased array antenna  635  and control circuitry  640 , each signal splitter  760  splits signals received by a corresponding sub-array  738  into first and second output signals. The first output signals are provided to a first set of phase shifters  789 ( 1 )- 789 ( 8 ), and the second output signals are provided to a second set of phase shifters  790 ( 1 )- 790 ( 8 ), as illustrated in  FIG. 18 . 
     The respective first and second phase shifters will be generally referred to by references  789  and  790 . The first output signals correspond to received television programming from the DES satellite  220  via antenna beam  650 , and the second output signals correspond to received Internet data from the FSS satellite  230  via antenna beam  660 . The second phase shifters  790  may also be used for forming the antenna beam  660  to transmit a request to the FSS satellite  230  for Internet data, as will be discussed in greater detail below. 
     Even though phase shifters  789 ,  790  are illustrated for directing the desired antenna beams  650  and  660 , amplitude weights may be used in place of the phase shifters. Alternatively, a combination of phase shifters and amplitude weights may be used as will be readily appreciated by those skilled in the art. The term phase array antenna thus includes phase shifters and/or amplitude weights for directing the desired antenna beams  650  and  660 . The term antenna beam shaping elements will be used to include phase shifters and/or amplitude weights. 
     A controller  710  is coupled to the phase shifters  789  and  790  to vary the phase shifts, and thus vary the direction of the antenna beams  650  and  660 . If the control circuitry  640  included amplitude weights as noted above, then the controller  710  would control the amplitude weights accordingly. 
     The controller  710  may operate as discussed above for controller  142 ,  142 ′ for tracking position of the satellites  220  and  230 , as will be readily appreciated by those skilled in the art. In other embodiments, the tracking may be based on position of the aircraft versus the position of the satellites  220  and  230 . The tracking may be an open loop pointing system based on GPS and/or inertial rate sensors, for example. 
     The first output signals from the first phase shifters  789  correspond to the television programming, which is receive only from the DBS satellite  220 . The outputs of the phase shifters  789  are provided to low noise amplifiers  791 ( 1 )- 791 ( 8 ). The respective low noise amplifiers will be generally referred to by reference  791 . The amplified signals from the low noise amplifiers  791  are collectively provided to a DBS combiner  780 ( a ) via signal paths  770 ( 1 )- 770 ( 8 ). For purposes of simplifying the drawing, connections A-H at the outputs of the low noise amplifiers  791  respectively connect with connections A-H at the inputs of the DES combiner  780 ( a ). 
     Similarly, the second output signals from the second phase shifters  790  correspond to received Internet data. The received Internet data is provided to a set of circulators  793 ( 1 )- 793 ( 8 ). The respective circulators will be generally referred to by reference  793 . The circulators  793  isolate transmit and receive Internet data from their intended transmit and receive signal paths, as will be readily appreciated by those skilled in the art. 
     On the receive side of the Internet data, the second output signals from the circulators  793  are provided to low noise amplifiers  795 ( 1 )- 795 ( 8 ). The respective low noise amplifiers will be generally referred to by reference  795 . The amplified signals from the low noise amplifiers  795  are collectively provided to an Internet-receive combiner  781 ( a ) via signal paths  771 ( 1 )- 771 ( 8 ). 
     On the transmit side of the phased array antenna  635  and control circuitry  640 , an Internet-transmit splitter  782 ( a ) provides the uplink request to high power amplifiers  797 ( 1 )- 797 ( 8 ) via signal paths  773 ( 1 )- 773 ( 8 ). The respective high power amplifiers will be generally referred to by reference  797 , and the respective signal paths will be generally referred to by reference  773 . The high power amplifiers  797  provide the amplified signals to the second phase shifters  790 . The phase shifted signals to be transmitted are then directed back through the splitters  760  to the respective sub-arrays  738  via the circulators  793 . 
     When the television programming is transmitted from the DES satellite  220 , two different orthogonal polarizations are used. To support receiving television programming in both polarizations, the phased array antenna  635  and control circuitry  640  provide more than one antenna polarization. 
     The phased array antenna  635  includes eight sub-arrays  738  for one polarization and another eight sub-arrays for an orthogonal polarization for a total of 16 sub-arrays. The sub-arrays for the orthogonal polarization are not illustrated to simplify  FIG. 18 . The illustrated sub-arrays  738  form antenna beam  650  for receiving television programming at one polarization. Although not illustrated, the other eight sub-arrays form another antenna beam for receiving television programming at an orthogonal polarization. 
     To support receiving television programming at the orthogonal polarization, another set of splitters and phase shifters are required in the control circuitry  640 , which are also not illustrated. However, the control circuitry  640  illustrates a DES combiner  780 ( a ) for one polarization, and a DES combiner  780 ( b ) for the orthogonal polarization. In other words, the second set of sub-arrays, splitters and phase shifters supporting the orthogonal polarization would be coupled to DES combiner  780 ( b ). 
     To correct the polarization based on the attitude of the aircraft  120 , the combined television programming from one polarization output from DBS combiner  780 ( a ) and the combined television programming from an orthogonal polarization output from DES combiner  780 ( b ) are provided to a polarization correction module  800 . The polarization correction module  800  includes an amplitude/phase trimmer  810  coupled to the DES combiner  780 ( a ) and an amplitude/phase trimmer  811  coupled to the DES combiner  780 ( b ), as illustrated in  FIG. 20 . The outputs from both of the amplitude/phase trimmers  810 ,  811  are summed by a summer  812 . A polarization controller  813  controls or adjusts the respective amplitude/phase trimmers  810 ,  811  based on the attitude of the aircraft  120 . The attitude of the aircraft  120  may be provided by the independent aircraft navigation system  553 , for example. The output of the summer  812  is provided to the satellite transceiver  242 . 
     When the Internet data is transmitted from the FSS satellite  230 , two different orthogonal polarizations are also used. One may be vertical polarization (VP) and the other may be horizontal polarization (HP), for example. The illustrated sub-arrays  738  form antenna beam  660  for receiving VP Internet data, for example. The other eight sub-arrays (not illustrated) form another antenna beam that is orthogonal to antenna beam  660  for receiving HP Internet data, for example. 
     To correct the polarization based on the attitude of the aircraft  120 , the combined VP Internet data output from Internet combiner  781 ( a ) and the combined HP Internet data output from Internet combiner  781 ( b ) are provided to a polarization correction module  801 . The polarization correction module  801  is similar to the polarization correction module  800  for the television programming. 
     A polarization correction module  802  is also used when transmitting from the phased array antenna  635  to the FSS satellite  230 . One output of the polarization correction module  802  is provided as input to the Internet splitter  782 ( a ), and the other output is provided as input to the Internet splitter  783 ( b ). On the transmit side, the Internet splitters  782 ( a ),  782 ( b ) split the signal to be transmitted for requesting the Internet data, whereas on the receive side, the Internet combiners  781 ( a ),  781 ( b ) combined the received Internet data. 
     For the multi-beam phased array antenna  635  to receive television programming from the OBS satellite  220  and Internet data from the FSS satellite  230 , the antenna beams for the composite satellite TV signal and the composite satellite Internet signal are thus different. The multi-beam phased array antenna  635  and the control circuitry  640  simultaneously generate the dual antenna beams  650  and  660 , with each antenna beam having a respective antenna beam boresight. When orthogonal polarization is taken into account, four antenna beams may be simultaneously generated, with each antenna beam having a respective antenna beam boresight. 
     The antenna beam shaping elements introduce a phase and/or amplitude shift. The phase shift may be introduced by dedicated phase shifters  789 ,  790  for the signal paths  770 ,  771  and  773 . The phase shifts may be fixed or adjustable. Alternatively, the phase shifts may be provided based on the delay introduced by the length of the signal paths  770 ,  771  and  773  so that the illustrated discrete phase shifters  789  and  790  may be representative of the phase shift created by the RF signal traces. Similarly, the amplitude shift may be introduced by dedicated amplitude weights for the signal paths  770 ,  771  and  773 . 
     In one embodiment, the phased array antenna  635  includes a substrate  680  and a plurality of antenna elements  682  thereon, as illustrated in  FIG. 20 . The phased array antenna  635  is not limited to this particular embodiment. Other embodiments include waveguides or dipoles, for example. 
     In yet another embodiment of the phased array antenna  635 ′, the antenna receives at two different frequencies as will now be discussed in reference to  FIGS. 21 and 22 . As a result, the splitters  760  are not required. In one embodiment, the antenna elements  782 ( 1 )′ and  782 ( 2 )′ are different sizes. A first plurality of antenna elements  782  ( 1 )′ is sized to operate at a first frequency, and a second plurality of antenna elements  782  ( 2 )′ is sized to operate at a second frequency different from the first frequency. 
     The first plurality of antenna elements  782 ( 1 )′ support the Ku frequency band, whereas the second plurality of antenna elements  782  ( 2 )′ support the Ka frequency band, for example. The different sized antenna elements  782 ( 1 )′,  782  ( 2 )′ may be interspersed with one another. As noted above, signal splitters are not needed. The remaining control circuitry  640 ′ is the same. 
     The frequency of the satellite TV signals received by the multi-beam phased array antenna  635  is within a frequency range of 10.7-12.75 GHz or 20-30 GHz for the DES satellite  220 . The frequency range of the satellite Internet signals can be between 4-6 GHz, 11-14 GHz and 20-30 GHz for the FSS satellite  230 . The illustrated phased array antenna  635  is configured to operate within the 10.7-18 GHz, which corresponds to the Ku band. The Ku band supports both reception of the satellite TV signals and the satellite Internet signals (when the satellite Internet signals are within the 11-14 GHz range). 
     As an alternative to electrically steering a phased array antenna, a mechanically steered antenna may be used. The mechanically steered antenna may be a phased array antenna as discussed above or may be a parabolic antenna, for example. Referring now to  FIGS. 23 and 24 , a dual-beam satellite antenna  835  includes a first aperture  837  for receiving the television programming, and a second aperture  839  adjacent the first aperture for receiving the Internet data. 
     A side view of the two apertures  837 ,  839  is provided in  FIG. 23 , and a top view of the two apertures is provided in  FIG. 24 . Although not shown, both of the apertures  837 ,  839  fit under the same radome  637 . By having two separate apertures  837  and  839 , the same or different frequencies can be supported and with different antenna beam pointing directions. 
     A first positioner  847  is coupled to the first aperture  837  to position toward the DES satellite  220 , for example. A second positioner  849  is coupled to the second aperture  839  to position toward the FSS satellite  230 , for example. Each aperture  837 ,  839  thus has its own positioner  847 ,  849 . A controller  850  is coupled to the positioners  847 ,  849  for control thereof. The controller  850  may operate as discussed above for controller  142 ,  142 ′ for tracking position of the satellites  220 ,  230  as will be readily appreciated by those skilled in the art. 
     The controller  850  may operate as discussed above for controller  142 ,  142 ′ for tracking position of the satellites  220  and  230 , as will be readily appreciated by those skilled in the art. In other embodiments, the tracking may be based on position of the aircraft versus the position of the satellites  220  and  230 . The tracking may be an open loop pointing system based on GPS and/or inertial rate sensors, for example. 
     As an alternative to each aperture  837 ′,  839 ′ having its own positioner, a common positioner  848 ′ may be used, as illustrated in  FIG. 25 . The first and second apertures  837 ′,  839 ′ have a fixed or variable antenna beam offset (electrical or mechanical) between their respective antenna beams. In one embodiment, the common positioner  838 ′ is used to position the first aperture  837 ′ so the antenna boresight associated therewith is pointed toward the DBS satellite  220 , and an offset controller  850 ′ is used to adjust the boresight of the second aperture  839 ′ associated therewith so that it is pointed at the FSS satellite  230 . 
     The offset controller  850 ′ may be configured to operate as a positioner. In other embodiments, the offset controller  850 ′ may vary the antenna beam shaping elements (i.e., phase shifters and/or amplitude weights) when the apertures are configured as phased array antennas. Alternatively, the offset controller  850 ′ may adjust the position of just one of the apertures with respect to the other aperture for obtaining the desired offset so that when common positioner  838 ′ is operated, the antenna beam offset between the two apertures is maintained. 
     In yet another embodiment, the common positioner  838 ′ points the respective antenna boresights associated with the first and second apertures  837 ′,  839 ′ so that both boresights are between the DBS and FSS satellites  220 ,  230 . The offset controller  850 ′ may then offset the antenna beams by half. 
     As with the phased array antennas  635  and  635 ′, different orthogonal polarizations may be supported by the first and second apertures  837 / 839  and  837 ′/ 839 ′. Consequently, polarization correction would be required to compensate for the attitude of the aircraft  120 , as discussed above for the polarization correction modules  800 ,  801  and  803 . 
     As noted above, the satellite TV signals provided by the DES satellite  220  are within a frequency range of 10.7-12.75 GHz or 20-30 GHz. Consequently, aperture  837 ,  837 ′ supports the Ku or Ka bands, which includes this frequency range. The other aperture  839 ,  839 ′ may be configured to support at least a portion of the frequency range within 10.7-30 GHz. This also corresponds to the Ku or Ka bands. Alternatively, both of the apertures  837 / 839  or  837 ′/ 839 ′ may operate in the same frequency range, such as the Ku band or Ka band, or one could operate in the Ku band whereas as the other one operates in the Ka band. 
     For the aperture  839 ,  839 ′ supporting the satellite Internet signals, the aperture may be used as an Internet forward channel. For the Internet reverse channel, a satellite channel may be used or an air-to-ground link from the aircraft  120  to the ground may be provided by an air-to-ground communications network  100 , as discussed above. Such an air-to-ground communications network  100  may comprise at least one personal electronic device (FED)  130  to be operated on the aircraft  120 . There is at least one access point  160  in the cabin of the aircraft  120  for providing a local area network for communicating with the FED. The air-to-ground transceiver  152  may be in the aircraft  120  and may be coupled to the at least one access point  160  for interfacing between the FED and the air-to-ground interface  200 . 
     Spaced apart ground-based base stations  140  may be used for communicating with the aircraft air-to-ground transceiver  152  over the air-to-ground interface  200 . The request for an Internet page (i.e., Internet reverse channel) by the PED  130  operating in the aircraft  120  is transmitted to the ground over the air-to-ground interface  200 . The request provided by the PED  130  is often referred to as the return link. The information from the FSS satellite  230  to the aircraft  120  is often referred to as the forward link. 
     The air-to-ground interface  200  is a narrow band interface, which is acceptable for making the Internet return or reverse link traffic since this request is typically a narrower band than the forward link. In contrast, the satellite link  252  is a wide band interface, which is ideal for providing requested web pages that are typically wide band data. 
     As noted above, the air-to-ground interface  200  is used to communicate with the ground-based base stations  140 . Each base station  140  interfaces with the public switched telephone network (PSTN)  141  and/or an Internet service provider (ISP)  142  through a switch  143  for providing data services that could include email and text messaging services. In this configuration, the web pages requested by a passenger would be performed using their PED  130  that communicates over the air-to-ground interface  200 . The message on the ground would then be routed to an appropriate ground based transmitter  145  (separate from the ground based base stations) for transmitting the request to the FSS satellite  230 . The FSS satellite  230  then transmits the web pages to the aircraft  120  over a satellite link  252  upon receiving the data from the ground. 
     Any of the above described embodiments for the antenna system can also be combined with a low gain switchable L-band antenna for L-band satellite connectivity service, with Iridium satellite communications being an example. The aircraft L-band antenna may be included in the same radome used for the satellite TV and Internet apertures as discussed above. For example, the L-band antenna may communicate via a satellite, or separate L-band antennas may be on the lower half of the aircraft for direct air-to-ground communications. 
     Many modifications and other embodiments of the invention will come to the mind of one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. In addition, other features relating to the aircraft communications system are disclosed in copending patent application filed on Oct. 15, 2008 assigned U.S. Ser. No. 12/252,296 and assigned to the assignee of the present invention and is entitled AIRCRAFT IN-FLIGHT ENTERTAINMENT SYSTEM HAVING A MULTI-BEAM PHASED ARRAY ANTENNA AND ASSOCIATED METHODS, the entire disclosure of which is incorporated herein in its entirety by reference. Therefore, it is understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included as readily appreciated by those skilled in the art.