Patent Publication Number: US-7587734-B2

Title: Aircraft in-flight entertainment system including a registration feature and associated methods

Description:
FIELD OF THE INVENTION 
   The present invention relates to the field of aircraft systems, and more particularly, to an aircraft in-flight entertainment system and associated methods. 
   BACKGROUND OF THE INVENTION 
   Commercial aircraft carry millions of passengers each year. For relatively long international flights, wide-body aircraft are typically used. These aircraft include multiple passenger aisles 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 and video entertainment systems for passenger enjoyment during relatively long flights. Typical wide-body aircraft 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 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 et al. The Sklar et 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 et 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. 
   A typical aircraft entertainment system for displaying TV broadcasts may include one or more satellite antennas, 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. 
   Published European patent application no. 557,058 for example, discloses a video and audio distribution system for an aircraft wherein the analog video signals are modulated upon individual RF carriers in a relatively low frequency range, and digitized audio signals, including digitized data, are modulated upon an RF carrier of a higher frequency to avoid interference with the modulated video RF carriers. All of the video and audio signals are carried by coaxial cables to area distribution boxes. Each area distribution box, in turn, provides individual outputs to its own group of floor distribution boxes. Each output line from a floor distribution box is connected to a single line of video seat electronic boxes (VSEB). The VSEB may service up to five or more individual seats. At each seat there is a passenger control unit and a seat display unit. Each passenger control unit includes a set of channel select buttons and a pair of audio headset jacks. Each display unit includes a video tuner that receives video signals from the VSEB and controls a video display. 
   A typical cable distribution network within an aircraft may be somewhat similar to a conventional coaxial cable TV system. For example, U.S. Pat. No. 5,214,505 to Rabowsky et al. discloses an aircraft video distribution system including amplifiers, taps and splitters positioned at mutually distant stations and with some of the stations being interconnected by relatively long lengths of coaxial cable. A variable equalizer is provided at points in the distribution system to account for different cable losses at different frequencies. The patent also discloses microprocessor-controlled monitoring and adjustment of various amplifiers to control tilt, that is, to provide frequency slope compensation. Several stations communicate with one another by a separate communication cable or service path independent of the RF coaxial cable. The patent further discloses maintenance features including reporting the nature and location of any failure or degradation of signals to a central location for diagnostic purposes. 
   There is a need for the seat electronic boxes (SEBs) to be registered in an in-flight entertainment system. Registration involves identifying a location of each SEB. Registration should be done on a regular basis, particularly when SEBs are being replaced or repaired. In fact, the replacement or repair of a single SEB usually requires the registration of all the SEBs installed on an aircraft. In some cases, this may be hundreds of units. 
   One method of registering SEBs requires maintenance or installation personnel to manually enter the corresponding serial numbers into a computer using a keyboard. This process can take several minutes, or even hours, depending on the number of personnel available. Even semi-automated registration sequences, in which maintenance personnel operate passenger control units (PCUs) associated with each SEB, require manual intervention and are generally slow and labor intensive. 
   SUMMARY OF THE INVENTION 
   In view of the foregoing background, it is therefore an object of the present invention to reduce the amount of time required for registering seat electronic boxes (SEBs) in an in-flight entertainment (IFE) system. 
   This and other objects, advantages and features in accordance with the present invention are provided by an aircraft in-flight entertainment system comprising a plurality of seat electronic boxes (SEBs) spaced throughout the aircraft, with each SEB being configurable for passing a registration token along to an adjacent SEB. Cabling may connect the SEBs together in a daisy chain configuration, and registration circuitry may be connected to the cabling for identifying a location of each SEB based upon passing of the registration token among the plurality of SEBs. 
   In particular, the registration circuitry may perform the following for identifying the location of each SEB. The plurality of SEBs are polled for a first SEB and a response is received from the first SEB, and registration confirmation is sent to the first SEB. The first SEB then passes the registration token to a next sequentially ordered SEB based upon the received registration confirmation. The plurality of SEBs may be polled for the next sequentially ordered SEB having the registration token, and a response is received therefrom. The registration circuitry may repeat the sending of registration confirmation and the polling for the next sequentially ordered SEB until a last sequentially ordered SEB has been registered. 
   The registration circuitry in accordance with the present invention advantageously reduces the amount of time required for registering SEBs in an in-flight entertainment system. Faster registration shortens the time that an in-flight entertainment system is down, thus increasing the availability and reliability of the system. 
   The registration circuitry, before polling the plurality of SEBs for the first SEB, may send a broadcast command to the plurality of SEBs for clearing any existing registrations in the registration circuitry. The registration circuitry may comprise a memory for storing a seating layout image of the aircraft. The location of the first SEB may be assigned based upon the stored seating layout image, and the location of the next sequentially ordered SEB may be determined with respect to the assigned location of the first SEB. 
   The registration circuitry may further comprise a control panel display, and a processor. The processor may be for displaying on the control panel display the seating layout image of the aircraft with respective locations of each SEB, and for generating information relating to operation of the SEBs. 
   The first SEB may include a ground pin connected to the cabling so that this SEB is identified as the first SEB. The response from each SEB may include a serial number associated therewith. The registration circuitry may assign a passenger row number and an aircraft side to each registered SEB. The aircraft side is with respect to the left or right side of the passenger aisle, for example. 
   In addition, the aircraft in-flight entertainment system further may comprise an entertainment source connected to the cabling, at least one video display unit (VDU) connected to each SEB, and a respective passenger control unit (PCU) associated with each of the video display units. The entertainment source may comprise at least one of a direct broadcast satellite (DBS) receiver, a terrestrial television (TV) receiver, and a satellite radio receiver for receiving radio signals. 
   Another aspect of the present invention is directed to a method for registering a plurality of SEBs for an aircraft IFE system, with the SEBs being connected together by cabling in a daisy chain configuration. The method comprises passing a registration token among the plurality of SEBs to thereby identify a location of each SEB. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a schematic diagram of the overall components of the aircraft in-flight entertainment system in accordance with the present invention. 
       FIGS. 2A and 2B  are a more detailed schematic block diagram of an embodiment of the in-flight entertainment system in accordance with the present invention. 
       FIG. 3  is a schematic rear view of a seatgroup of the in-flight entertainment system of the invention. 
       FIG. 4  is a flowchart for a first method aspect relating to the in-flight entertainment system of the invention. 
       FIG. 5  is a flowchart for a second method aspect relating to the in-flight entertainment system of the invention. 
       FIG. 6  is a more detailed schematic block diagram of a first embodiment of an antenna-related portion of the in-flight entertainment system of the invention. 
       FIG. 7  is a side elevational view of the antenna mounted on the aircraft of the in-flight entertainment system of the invention. 
       FIG. 8  is a more detailed schematic block diagram of a second embodiment of an antenna-related portion of the in-flight entertainment system of the invention. 
       FIGS. 9-11  are simulated control panel displays for the in-flight entertainment system of the invention. 
       FIG. 12  is a schematic diagram of a portion of the in-flight entertainment system of the invention illustrating a soft-fail feature according to a first embodiment. 
       FIG. 13  is a schematic diagram of a portion of the in-flight entertainment system of the invention illustrating a soft-fail feature according to a second embodiment. 
       FIG. 14  is a schematic diagram of a portion of the in-flight entertainment system of the invention illustrating a moving map feature according to a first embodiment. 
       FIG. 15  is a schematic diagram of a portion of the in-flight entertainment system of the invention illustrating a moving map feature according to a second embodiment. 
       FIG. 16  is a schematic diagram of a portion of the in-flight entertainment system illustrating registration circuitry in accordance with the invention. 
       FIG. 17  is a flowchart of a method for registering seat electronic boxes for an in-flight entertainment system in accordance with the invention. 
       FIG. 18  is a schematic diagram of a portion of the in-flight entertainment system including digital radio receivers at the headend unit in accordance with the invention. 
       FIG. 19  is a schematic diagram of an aircraft illustrating another embodiment of the in-flight entertainment system illustrated in  FIG. 18 . 
       FIG. 20  is a more detailed block diagram of a seat electronic box illustrated in  FIG. 18 . 
       FIG. 21  is a more detailed block diagram of a passenger control unit illustrated in  FIG. 18 . 
       FIG. 22  is a schematic diagram of a portion of the in-flight entertainment system including digital radio receivers at the seat electronic boxes in accordance with the invention. 
       FIG. 23  is a more detailed block diagram of the seat electronic box illustrated in  FIG. 22 . 
       FIG. 24  is a schematic diagram of an aircraft illustrating another embodiment of the in-flight entertainment system illustrated in  FIG. 22 . 
       FIG. 25  is a schematic diagram of a portion of the in-flight entertainment system illustrating a distributed memory in accordance with the invention. 
       FIG. 26  is a more detailed block diagram of the seat electronic box illustrated in  FIG. 25 . 
       FIG. 27  is a schematic block diagram of a portion of the in-flight entertainment system illustrating operation of a portable wireless device with an aircraft in-flight entertainment system in accordance with the invention. 
       FIG. 28  is a flowchart of a method for operating a portable wireless device with an aircraft in-flight entertainment system in accordance with the invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   The present invention will 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 alternate embodiments. 
   The major components of an in-flight entertainment system  30  in accordance with the present invention are initially described with reference to  FIGS. 1 through 3 . The system  30  receives television and/or audio broadcast signals via one or more geostationary satellites  33 . The geostationary satellite  33  may be fed programming channels from a terrestrial station  34  as will be appreciated by those skilled in the art. 
   The in-flight entertainment system  30  includes an antenna system  35  to be mounted on the fuselage  32  of the aircraft  31 . In addition, the system  30  also includes one or more multi-channel receiver modulators (MRMs)  40 , a cable distribution network  41 , a plurality of seat electronic boxes (SEBs)  45  spaced about the aircraft cabin, and video display units (VDUs)  47  for the passengers and which are connected to the SEBs. In the illustrated embodiment, the system  30  receives, distributes, and decodes the DBS transmissions from the DBS satellite  33 . In other embodiments, the system  30  may receive video or TV signals from other classes of satellites as will be readily appreciated by those skilled in the art. 
   The antenna system  35  delivers DBS signals to the MRMs  40  for processing. For example, each MRM  40  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. 2A and 2B , an audio video modulator (AVM)  50  is connected to the MRMs  40 , as well as a number of other inputs and outputs. The AVM  50  illustratively receives inputs from an external camera  52 , as well as one or more other video sources  54 , such as videotape sources, and receives signal inputs from one or more audio sources  56  which may also be prerecorded, for example. A PA keyline input and PA audio input are provided for public address and video address override. Audio for any receiver along with an associated keyline are provided as outputs from the MRM 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  51  is provided as part of the AVM  50 . The control panel  51  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  50  is also illustratively coupled to a ground data link radio transceiver  57 , such as for permitting downloading or uploading of data or programming information. The AVM  50  is also illustratively interfaced to an air-to-ground telephone system  58  as will be appreciated by those skilled in the art. 
   The AVM  50  illustratively generates a number of NTSC video outputs which may be fed to one or more retractable monitors  61  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  40  may perform system control, and status monitoring. An RF distribution assembly (RDA)  62  can be provided to combine signals from a number of MRMs, such as four, for example. The RDA  62  combines the MRM RF outputs to create a single RF signal comprising up to 48 audio/video channels, for example. The RDA  62  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  31 . Depending on the aircraft, not all eight outputs may be used. Each cable will serve a zone of seatgroups  65  in the passenger cabin. 
   Referring now more specifically to the lower portion of  FIG. 2B  and also to  FIG. 3 , distribution of the RF signals and display of video to the passengers is now further described. Each zone cable  41  feeds the RF signal to a group of contiguous seatgroups  65  along either the right or lefthand side of the passenger aisle. In the illustrated embodiment, the seatgroup  65  includes three side-by-side seats  66 , although this number may also be two for other types of conventional narrow-body aircraft. 
   The distribution cables  41  are connected to the first SEB  45  in each respective right or left zone. The other SEBs  45  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 cycle power cable, and RS 485 data wiring. 
   For each seat  66  in the group  65 , the SEB  45  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)  68  and headphones  70 , respectively. The tuner channels are under control of the passenger control unit (PCU)  71 , typically mounted in the armrest of the seat  66 , and which also carries a volume control. 
   Each VDU  68  may be a flat panel color display mounted in the seatback. The VDU  68  may also be mounted in the aircraft bulkhead in other configurations as will be appreciated by those skilled in the art. The VDU  68  will also typically include associated therewith a user payment card reader  72 . The payment card reader  72  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  72  may also be used as the single input required to activate the system for enhanced user convenience. 
   Having now generally described the major components of the in-flight entertainment system  30  and their overall operation, the description now is directed to several important features and capabilities of the system in greater detail. One such feature relates to flexibility or upgradability of the system as may be highly desirable for many airline carriers. In particular, the system  30  is relatively compact and relatively inexpensive so that it can be used on narrow-body aircraft  31 , that is, single-aisle aircraft. Such narrow-body aircraft  31  are in sharp contrast to wide-body aircraft typically used on longer overseas flights and which can typically carry greater volumes and weight. The narrow-body aircraft  31  are commonly used on shorter domestic flights 
   The system  30 , for example, can be first installed to provide only audio. In addition, the first class passengers may be equipped with seat back VDUs  68 , while the coach section includes only aisle mounted video screens. The important aspect that permits upgradability is that the full cable distribution system is installed initially to thereby have the capacity to handle the upgrades. In other words, the present invention permits upgrading and provides reconfiguration options to the air carrier for an in-flight entertainment system and while reducing downtime for such changes. 
   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  31  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  66 . 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. 
   Referring now additionally to the flow chart of  FIG. 4 , a method for installing and operating an aircraft in-flight entertainment system in accordance with the invention is now described. After the start (Block  80 ), the method preferably comprises installing at least one entertainment source on the aircraft at Block  82 . The entertainment source may include a satellite TV source, such as provided by the DBS antenna system  35  and MRMs  40  described above. The method at Block  84  also preferably includes installing a plurality of spaced apart signal distribution devices, 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  45  described above as will be readily appreciated by those skilled in the art. The SEBs  45  include the capability for both audio and video when initially installed to thereby provide the flexibility for upgrading. 
   At Block  86  the cable network is installed on the aircraft  31  connecting the at least one entertainment source to the signal distribution devices. In other words, the MRMs  40  are connected to the SEBs  45  in the various equipped zones throughout the aircraft  31 . Operating the aircraft in-flight entertainment system  30  at Block  88  with at least one predetermined signal distribution device in the audio-only mode, permits initial weight and cost savings since the VDUs  68 , for example, may not need to be initially installed for all passengers as will be appreciated by those skilled in the art. For example, a carrier may initially decide to equip first class passengers with both video and audio entertainment options, while coach passengers are initially limited to audio only. Hence, the cost of the VDUs  68  for the coach passengers is initially deferred. 
   Installing the cabling  41  and SEBs  45  at one time will result in substantial time and labor savings as compared to a piecemeal approach to adding these components at a later time as needed. Accordingly, should an upgrade be desired at Block  90 , this may be readily accomplished by connecting at least one VDU  68  to the at least one predetermined signal distribution device, or SEB  45 , to operate in the audio/video mode and while leaving the cable network unchanged (Block  92 ). Accordingly, the downtime experienced by air carrier is greatly reduced over other systems which require significant recabling and other difficult equipment installation operations for upgrading. The method is particularly advantageous for a single-aisle narrow-body aircraft  31  as shown in the illustrated embodiment, where cost effectiveness and low weight are especially important. 
   As noted above, the entertainment source may preferably comprise a DBS receiver. The step of later upgrading may further comprise leaving the at least one predetermined signal distribution device, such as the SEB  45 , unchanged. The step of installing the cable network  41  may comprise installing coaxial cable, power cable and data cable throughout the aircraft as also described above. The step of later upgrading may include installing at least one VDU  68  in the aircraft  31 , such as on backs of passenger seats  66 . 
   Of course, the aircraft  31  in some embodiments may include different seating classes as will be appreciated by those skilled in the art. Accordingly, another important aspect of the invention relates to offering different entertainment services based upon the different seating classes at Block  94 . In addition, the different seating classes may be reconfigurable, and the step of reconfiguring offered entertainment services may then be based upon reconfiguring of the seating classes. The offering of different entertainment services may comprise offering different packages of television channels, for example. In addition, the step of offering different entertainment services may comprise offering audio-only and audio/video modes of operation based upon seating classes. 
   Yet another aspect of the invention relates to a method for operating an aircraft in-flight entertainment system  30  for an aircraft  31  when seating classes are reconfigured. Continuing down the flowchart of  FIG. 4 , this aspect of the method preferably comprises determining whether a reconfiguration is desired at Block  96 , and reconfiguring offered entertainment services based upon reconfiguring of the seating classes at Block  98  before stopping at Block  100 . For example, the step of offering different entertainment services may include offering different packages of television channels. Alternatively, the step of offering different entertainment services may comprise offering audio-only and audio/video modes of operation based upon seating classes. In either case, the reconfiguring can be readily accomplished using the existing cable distribution network  41  and distribution devices, that is, SEBs  45  as will be appreciated by those skilled in the art. 
   The various upgrading and reconfiguring aspects of the in-flight entertainment system  30  can be performed in a reverse sequence than that illustrated in  FIG. 4  and described above. Of course, the upgrade steps may be practiced without the later reconfiguring steps as will be appreciated by those skilled in the art. 
   To further illustrate the method aspects, the flowchart of  FIG. 5  is directed to the subset of offering different services and later reconfiguring those services based upon reconfiguring seating. More particularly, from the start (Block  110 ), the in-flight entertainment system  30  is installed at Block  112  and operated (Block  114 ) offering different services based upon seating class, such as offering video to first class passengers, and offering only audio to non-first class passengers. If it is determined that the seating should be reconfigured at Block  116 , then the in-flight entertainment system  30  can be readily reconfigured at Block  118  before stopping (Block  120 ). 
   Turning now additionally to  FIGS. 6 and 7 , advantages and features of the antenna system  35  are now described in greater detail. The antenna system  35  includes an antenna  136  which may be positioned or steered by one or more antenna positioners  138  as will be appreciated by those skilled in the art. In addition, one or more position encoders  141  may also be associated with the antenna  136  to steer the antenna to thereby track the DBS satellite or satellites  33 . 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 of the present invention, the antenna  136  may be steered using received signals in the relatively wide bandwidth of at least one DBS transponder. 
   More particularly, the antenna system  35  includes an antenna steering controller  142 , which, in turn, comprises the illustrated full transponder bandwidth received signal detector  143 . This detector  143  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. 
   In the illustrated embodiment, the detector  143  is coupled to the output of the illustrated intermediate frequency interface (IFI)  146  which converts the received signals to one or more intermediate frequencies for further processing by the MRMs  40  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  146  may also be used to couple the received signal from one or more full satellite transponders to the received signal strength detector  143  as will also be appreciated by those skilled in the art. 
   A processor  145  is illustratively connected to the received signal strength detector  143  for controlling the antenna steering positioners  138  during aircraft flight and based upon the received signal strength feedback signal. Accordingly, tracking of the satellite or satellites  33  is enhanced and signal service reliability is also enhanced. 
   The antenna steering controller  142  may further comprise at least one inertial rate sensor  148  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  148  may be provided by one or more solid state gyroscopes, for example. The processor  145  may calibrate the rate sensor  148  based upon the received signal strength feedback signal. 
   The illustrated antenna system  35  also includes a global positioning system (GPS) antenna  151  to be carried by the aircraft fuselage  32 . 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  142  also illustratively includes a GPS receiver  152  connected to the processor  145 . The processor  145  may further calibrate the rate sensor  148  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  145  may be a commercially available microprocessor operating under stored program control. Alternatively, discrete logic and other signal processing circuits may be used for the processor  145 . 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 of the invention 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  136 . 
   Another advantage of the antenna system  35  is that it may operate independently of the aircraft navigation system  153  which is schematically illustrated in the lower righthand portion of  FIG. 6 . In other words, the aircraft  31  may include an aircraft navigation system  153 , and the antenna steering controller  142  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  153  as will be appreciated by those skilled in the art. In addition, the antenna system  35  is also particularly advantageous for a single-aisle narrow-body aircraft  31  where cost effectiveness and low weight are especially important. 
   Turning now additionally to  FIG. 8 , another embodiment of the antenna system  35 ′ 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 invention 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 of the invention 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 antenna  136 ′ 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. 8 ) 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  33   a ,  33   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  136 ′ 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  136 ′ 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  145 ′ preferably steers the antenna  136 ′ based upon received signals from at least one of the RHCP and LHCP beams which are processed via the IFI  146 ′ and input into respective received signal strength detectors  143   a ,  143   b  of the antenna steering controller  142 ′. In one embodiment, the processor  145 ′ steers the multi-beam antenna  136 ′ based on a selected master one of the RHCP and LHCP beams and slaves the other beam therefrom. 
   In another embodiment, the processor  145 ′ steers the multi-beam antenna  136 ′ 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 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  33   a ,  33   b  is that more programming channels may then be made available to the passengers. 
   The antenna system  35 ′ may also advantageously operate independent of the aircraft navigation system  153 ′. The other elements of  FIG. 8  are indicated by prime notation and are similar to those described above with respect to  FIG. 6 . Accordingly, these similar elements need no further discussion. 
   Another aspect of the invention relates to the inclusion of adaptive polarization techniques that 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  30 . Adaptive polarization techniques would also be desirable should assigned orbital slots for satellites be moved closer together. 
   Accordingly, the processor  145 ′ 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  30  in accordance with the present invention without further discussion. 
   Other aspects and advantages of the in-flight entertainment system  30  of the present invention are now explained with reference to  FIGS. 9-11 . The system  30  advantageously incorporates a number of self-test or maintenance features. As will be appreciated by those skilled in the art, the maintenance costs to operate such a system  30  could be significantly greater than the original purchase price. Accordingly, the system  30  includes test and diagnostic routines to pinpoint defective equipment. In particular, the system  30  provides the graphical representation of the aircraft seating arrangement to indicate class of service, equipment locations, and failures of any of the various components to aid in maintenance. 
   As shown in  FIG. 9 , the system  30  includes a control panel display  51 , and a processor  160  connected to the control panel display. The control panel display  51  and processor  160  may be part of the AVM  50  ( FIG. 1 ), but could be part of one or more of the MRMs  40  ( FIG. 1 ), or part of another monitoring device as will be appreciated by those skilled in the art. The control panel display  51  may be touch screen type display including designated touch screen input areas  163   a - 163   d  to also accept user inputs as would also be appreciated by those skilled in the art. 
   More particularly, the processor  160  generates a seating layout image  170  of the aircraft on the control panel display  51  with locations of the signal distribution devices located on the seating layout image. These locations need not be exact, but should be sufficient to direct the service technician to the correct left or right side of the passenger aisle, and locate the seatgroup and/or seat location for the defective or failed component. In addition, the locations need not be constantly displayed; rather, the location of the component may only be displayed when service is required, for example. 
   The processor  160  also preferably generates information relating to operation of the signal distribution devices on the display. The signal distribution devices, for example, may comprise demodulators (SEBs  45 ), modulators (MRMs  40 ), or the video passenger displays (VDUs  68 ), for example. Accordingly, a user or technician can readily determine a faulty component and identify its location in the aircraft. 
   As shown in the illustrated embodiment of  FIG. 9 , the representative information is a failed power supply module of the #4 SEB of zone  5 . In  FIG. 10 , the information is for a failed #4 MRM. This information is illustratively displayed in text with an indicator pointing to the location of the device. In other embodiments, a flashing icon or change of color could be used to indicate the component or signal distribution device requiring service as will be appreciated by those skilled in the art. 
   This component mapping and service needed feature of the invention can be extended to other components of the system  30  as will be readily appreciated by those skilled in the art. For example, the processor  160  may further generate information relating to operation of the entertainment source, such as the DBS receiver, or its antenna as shown in  FIG. 11 . Again, the technician may be guided to the location of the failed component from the seat image layout  170 . 
   Returning again briefly to  FIG. 9 , another aspect of the invention relates to display of the correct seating layout  170  for the corresponding aircraft  31 . As shown, the display  51  may also include an aircraft-type field  171  that identifies the particular aircraft, such as an MD-80. The corresponding seating layout data can be downloaded to the memory  162  or the processor  160  by a suitable downloading device, such as the illustrated laptop computer  161 . In other embodiments, the processor  160  may be connected to a disk drive or other data downloading device to receive the seat layout data. 
   The seat layout data would also typically include the data for the corresponding locations of the devices installed as part of the in-flight entertainment system  30  on the aircraft as will be appreciated by those skilled in the art. Accordingly, upgrades or changes in the system  30  configuration may thus be readily accommodated. 
   Another aspect of the invention relates to a soft failure mode and is explained with reference to  FIGS. 12 and 13 . A typical DBS system provides a default text message along the lines “searching for satellite” based upon a weak or missing signal from the satellite. Of course, an air traveler may become disconcerted by such a message, since such raises possible questions about the proper operation of the aircraft. In other systems, a weak received signal may cause the displayed image to become broken up, which may also be disconcerting to the air traveler. 
   The system  30  as shown in  FIG. 12  of the present invention includes a processor  175  which may detect the undesired condition in the form of a weak or absent received signal strength, and cause the passenger video display  68  to display a substitute image. More particularly, the processor  175  may be part of the AVM  50  as described above, could be part of another device, such as the MRM  40 , or could be a separate device. 
   The processor  175  illustratively includes a circuit or portion  176  for determining a weak received signal strength as will be appreciated by those skilled in the art. Suitable circuit constructions for the weak received signal strength determining portion or circuit  176  will be readily appreciated by those skilled in the art, and require no further discussion herein. The threshold for the weak received signal strength determining portion or circuit  176  can preferably be set so as to trigger the substitute image before substantial degradation occurs, or before a text default message would otherwise be triggered, depending on the satellite service provider, as would be appreciated by those skilled in the art. In addition, the substitute image could be triggered for a single programming channel upon a weakness or loss of only that single programming channel, or may be generated across the board for all programming channels as will be readily appreciated by those skilled in the art. 
   In the illustrated system  30  of  FIG. 12 , a substitute image storage device  178  is coupled to the processor  175 . This device  178  may be a digital storage device or a video tape player, for example, for causing the passenger video display  68  to show a substitute image. For example, the image could be a text message, such as “LiveTV™ Service Temporarily Unavailable, Please Stand By”. Of course, other similar messages or images are also contemplated by the invention, and which tend to be helpful to the passenger in understanding a loss of programming service has occurred, but without raising unnecessary concern for the proper operation of the aircraft  31  to the passenger. 
   This concept of a soft failure mode, may also be carried forward or applied to a component malfunction, for example. As shown in the system  30 ′ of  FIG. 13 , a component malfunctioning determining portion or circuit  177 ′ is added to the processor  175 ′ and can be used in combination with the weak received signal strength determining portion  176 ′. Of course, in other embodiments the malfunction determining circuit portion  177 ′ could be used by itself. Again, rather than have a disconcerting image appear on the passenger&#39;s video display  68 ′, a substitute image may be provided. Those of skill in the art will appreciate that the weak received signal strength and component malfunction are representative of types of undesired conditions that the present system  30  may determine and provide a soft failure mode for. The other elements of  FIG. 13  are indicated by prime notation and are similar to those described above with respect to  FIG. 12 . Accordingly, these similar elements need no further discussion. 
   Yet another advantageous feature of the invention is now explained with reference to  FIG. 14 . Some commercial aircraft provide, on a common cabin display or overhead monitor, a simulated image of the aircraft as it moves across a map between its origin and destination. The image may also include superimposed data, such as aircraft position, speed, heading, altitude, etc. as will be appreciated by those skilled in the art. 
   The in-flight entertainment system  30  of the invention determines or receives the aircraft position during flight and generates a moving map image  195  of the aircraft as a flight information video channel. Various flight parameters  196  can also be displayed along with the moving map image  195 . This flight information channel is offered along with the DBS programming channels during aircraft flight. In the illustrated embodiment, the passenger may select the flight information channel to be displayed on the passenger video display  68  using the passenger control unit (PCU)  71  which is typically mounted in the armrest as described above. In other words, the flight information channel is integrated along with the entertainment programming channels from the DBS system. 
   As shown in the illustrated embodiment, the moving map image  195  including other related text, such as the flight parameters  196 , may be generated by the illustrated AVM  50  and delivered through the signal distribution network  41  to the SEB  45 . Since the antenna steering controller  142  ( FIG. 6 ) includes circuitry for determining the aircraft position, etc., these devices may be used in some embodiments for generating the moving map image as will be appreciated by those skilled in the art. 
   For example, the GPS receiver  152  and its antenna  151  can be used to determine the aircraft position. The GPS receiver  152  is also used to steer the antenna in this embodiment. In other embodiments a separate GPS receiver may be used as will be appreciated by those skilled in the art. As will also be appreciated by those skilled in the art, the inertial rate sensor(s)  148  of the antenna steering controller  142  may also be used in some embodiments for generating flight information. 
   The processor  190  illustratively includes a parameter calculator  191  for calculating the various displayed flight parameters  196  from the position signal inputs as will be appreciated by those skilled in the art. For example, the parameter calculator  191  of the processor  190  may determine at least one of an aircraft direction, aircraft speed and aircraft altitude for display with the map image. Information may also be acquired from other aircraft systems, such as an altimeter  197 , for example, as will be appreciated by those skilled in the art. Also, the illustrated embodiment includes a map image storage device  192  which may include the various geographic maps used for the moving map image  195 . 
   Weather information may also be added for display along with the moving map image  195 . Further details on the generation and display of moving map images may be found in U.S. Pat. No. 5,884,219 to Curtwright et al. and U.S. Pat. No. 5,992,882 to Simpson et al., the entire disclosures of which are incorporated herein by reference. 
   Referring now briefly additionally to  FIG. 15 , another embodiment of the system  30 ′ including the capability to display a flight information channel among the offered DBS or satellite TV channels is now described. In this embodiment, a moving map image generator  198 ′ is added as a separate device. In other words, in this embodiment, the flight channel signal is only carried through the distribution cable network  41 ′ and delivered via the SEB  45 ′ to the passenger video display  68 ′, and there is no interface to the components of the antenna steering controller  142  as in the embodiment described with reference to  FIG. 14 . In this embodiment, the moving map image generator  198 ′ may include its own position determining devices, such as a GPS receiver. Alternatively, the moving map image generator  198 ′ may also receive the position data or even the image signal from a satellite or terrestrial transmitter. 
   Another aspect of the invention relates to an in-flight entertainment (IFE) system  300  comprising registration circuitry  302  for identifying a location of each SEB  345   a - 345   n  within the aircraft, as illustrated in  FIG. 16 . The IFE system  300  comprises a plurality of seat electronic boxes (SEBs)  345   a - 345   n  spaced throughout the aircraft, with each SEB being configurable for passing a registration token along to an adjacent SEB. The SEBs are arranged from a first SEB  345   a  to a last SEB  345   n . Cabling  341  connects the SEBs  345   a - 345   n  together in a daisy chain configuration. In addition, video display units (VDUs)  347  and passenger control units (PCUs)  371  for the passengers are connected to the SEBs  345   a - 345   n . In the illustrated embodiment, each SEB supports three passengers. 
   The registration circuitry  302  is carried by a headend unit  320 , and is connected to the cabling  341  for identifying a location of each SEB  345   a - 345   n  based upon passing of the registration token among the plurality of: SEBs. The registration circuitry  302  includes a control panel display  304 , a processor  306  connected to the control panel display, and a memory  308  connected to the processor. 
   The registration circuitry  302  may be a standalone unit, or it may be part of the other electronic equipment on-board the aircraft. For instance, the illustrated headend unit  320  may also include an audio/video modulator (AVM)  350 , at least one multi-channel receiver/modulator (MRM)  340  and an RF distribution assembly (RDA)  362  as discussed above. This electronic equipment interfaces between an entertainment source  330  and the cabling  341 . Instead of a standalone unit, the registration circuitry  302  may be part of the AVM  350 , the MRM  340  or the RDA  362  as will be appreciated by those skilled in the art. 
   The processor  306  displays on the control panel display  304  the seating layout image of the aircraft with respective locations of each SEB  345   a - 345   n , and generates information relating to registration of the SEBs. Data related to the seating layout image of the aircraft is stored in the memory  308 , which may be separate from the processor  306 . Alternatively, the memory  308  may be embedded within the processor  306 . The corresponding seating layout data can be downloaded to the memory  308  by a suitable downloading device, such as a laptop computer  338 . The locations of the SEBs  345   a - 345   n  need not be exact, but should be sufficient to communicate to the service technician where on the aircraft each registration SEB is located, i.e., on the left or right side of the passenger aisle, and the seat group and/or seat location of each registered SEB. 
   In the control panel display  304 , the locations of the registered SEBs  345   a - 345   n  need not be constantly displayed. The location of the SEBs  345   a - 345   n  need only be displayed when registration is being performed. Information relating to registration of the SEBs  345   a - 345   n  may be in tabular form in lieu of a seating layout image of the aircraft, as will also be appreciated by those skilled in the art. 
   Referring now additionally to the flowchart of  FIG. 17 , a method for registering the plurality of SEBs  345   a - 345   n  for the aircraft IFE system  300  will be discussed. From the start (Block  352 ), the method initially comprises connecting the plurality of SEBs  345   a - 345   n  together in a daisy chain configuration using cabling  341  at Block  354 , with each SEB being configurable for passing a registration token along to an adjacent SEB. 
   A broadcast command is sent at Block  356  from the registration circuitry  302  to the SEBs  345   a - 345   n  for clearing any existing registrations. The processor  306  then polls each SEB  345   a - 345   n  at Block  358  to determine the first SEB  345   a , and a response is received from the first SEB. It is necessary to determine the first SEB  345   a  within the sequence of the SEBs as defined by the daisy chain configuration. The first SEB  345   a  thus becomes a known point of reference for continuing the registration process. 
   In other words, the processor  306  matches the known point of reference with respect to the seating layout image of the aircraft stored within the memory  308 . For example, the first SEB  345   a  may be located in the first row on the left hand side of the passenger aisle. Alternatively, the first SEB  345   a  may be located in the last row on the right hand side of the passenger aisle, for example. 
   When the SEBs  345   a - 345   n  are polled at Block  358  to determine the first SEB  345   a , a serial protocol may be used. The serial protocol may be an RS-485 serial protocol, for example. Of course, other protocols may be used. For instance, an Ethernet network may be used as readily appreciated by those skilled in the art. The registration token is active within the first SEB  345   a  via a ground pin  346  connected to ground. The ground pin  346  may be connected to the ground associated with the cabling  341 . 
   As part of the polling process, the registration circuitry  302  sends a broadcast “electronic registration token” request command to all of the SEBs  345   a - 345   n . The SEB having the registration token responds with a “registration token acknowledgement” response that contains its corresponding serial number. The electronic registration token is an electronic flag that provides a way of identifying the physical location of the SEB being interrogated. When active, the electronic registration flag or token signal indicates that any SEB is the next sequentially ordered SEB in the chain to be registered by the registration circuitry  302 . 
   Since any previous registrations of the SEBs  345   a - 345   n  have been cleared in Block  356 , the first active registration token signal to be detected is associated with the first SEB, which in the illustrated example is SEB  345   a . This SEB  345   a  is the first SEB because it is the only one with an active token signal due to its ground pin  346  being grounded to the cabling  341 . The registration circuitry  302  determines the corresponding row number and aircraft side based on the fact that the location of the first SEB is predetermined. 
   Once the registration circuitry  302  receives a response from the first SEB  345   a , the registration circuitry sends registration confirmation to the first SEB and the electronic registration token is passed to the next sequentially ordered SEB  345   b  in the daisy chain in the direction from the first SEB to the last SEB  345   n  at Block  360 . At Block  364 , the SEBs  345   a - 345   n  are polled for the next sequentially ordered SEB having the registration token, and a response is received from the SEB having the registration token. The sending of registration confirmation and the polling for the next sequentially ordered SEB are repeated at Block  366  until a last sequentially ordered SEB  345   n  has been registered. Once the last SEB  345   n  has been registered, the method ends at Block  368 . 
   During the registration process, all SEBs  345   a - 345   n  without the registration token ignore the polling command, i.e., they do not respond. Registration includes adding the serial number, row number, and aircraft side of each SEB to a database stored in the memory  308 . The registration circuitry  302  determines the row number and aircraft side of the responding SEB based on the known location of the first SEB  345   a , and from which the responding SEB received the token signal. 
   As described above, a ground or selection pin  346  is used in the automatic registration sequence as a way for the registration circuitry  302  to electronically locate the first SEB  345   a  and begin the automatic registration sequence. The SEBs  345   a - 345   n  are typically divided into zones, with each zone including a set of SEBs. In an alternative embodiment, each set of SEBs (within a zone) has its own first SEB. Consequently, the first SEB in each zone has a plurality of pins associated therewith, and the plurality of pins are grounded to represent a distinct number for identifying a first SEB in one zone from a first SEB in a different zone. The registration token is still passed within each zone, as well as being passed from zone to zone as part of the registration process. In addition, a ground pin may be used to identify which side of the aircraft the equipment is on. 
   In another embodiment, the ground pin  346  may be eliminated. In this embodiment, the controls of a corresponding PCU  371  may be manually activated to allow the registration circuitry  302  to electronically locate the first SEB  345   a  and begin the automatic registration sequence. 
   As noted above, manual and semi-automated processes for registering the SEBs  345   a - 345   n  require maintenance personnel to operate the corresponding PCUs  371  in sequence during the registration process. Operation of several PCUs  371  may be a time-intensive and complex process. Registration of SEBs  345   a - 345   n  in accordance with the present invention advantageously eliminates the need for maintenance personnel to operate the PCUs  371 , and thus simplifies the registration process. 
   As a result of the reduced time necessary for registering all of the SEBs  345   a - 345   n , individual SEBs and other components of IFE system  300  can be repaired and/or replaced quickly during short aircraft layovers, thereby reducing the time necessary to service the IFE system. This reduced repair time helps to increase both the availability and the reliability of the IFE system  300 . 
   Turning now additionally to  FIG. 18 , another feature of the present invention is directed to an in-flight entertainment (IFE) system  400  receiving live audio broadcasts from a satellite  433 . The IFE system  400  includes a headend unit  402  and a plurality of seat electronic boxes (SEBs)  445  spaced throughout the aircraft. The headend unit  402  comprises a plurality of digital satellite radio receivers  404 . A local area network (LAN)  441  connects the digital satellite radio receivers  404  to the plurality of SEBs.  445  for providing digital satellite radio signals thereto. Instead of a plurality of digital satellite radio receivers  404  in the headend unit  402 , there may be one digital satellite radio receiver for providing the desired channels. 
   In lieu of an aircraft, the entertainment system receiving live audio broadcasts from a satellite  433  is also applicable to an area other than an aircraft. The area, which may be a building or office complex for example, may be divided into a plurality of zones and each electronic box is within a respective zone. 
   The LAN  441  preferably comprises an Ethernet network, which may be configured by a twisted pair wire, a coaxial cable or a fiber optic cable. The LAN  441  may be a wired LAN as illustrated, or a wireless LAN as illustrated in  FIG. 19 , or a combined wired/wireless interface. In the wireless LAN, the headend unit  402 ′ includes a radio module and an antenna  449 ′ connected thereto for providing the digital satellite radio signals to the SEBs  445 ′. Each SEB  445 ′ has an antenna  448 ′ associated therewith for receiving the digital satellite radio signals. The wireless LAN is based upon the 802.11 protocol, for example, and each SEB  445 ′ has a different address associated therewith, as readily understood by those skilled in the art. 
   The digital satellite radio receivers  402  are connected to an antenna  436  receiving the digital satellite radio signals, and are compatible with at least one of a variety of digital satellite radio satellites  433 , such as a Sirius radio satellite, an XM radio satellite or a WorldSpace satellite, for example. For purposes of illustrating the present invention, the XM radio satellite will be used as an example. The XM radio satellite transmits 101 channels of digital satellite radio signals within the frequency range of 2.33 to 2.34 GHz. Since each digital satellite radio receiver  404  supports 4 to 6 channels, the IFE system  400  typically comprises between 17 to 25 digital satellite radio receivers. The digital satellite radio receivers  404  may be implemented as a chip set, as readily appreciated by those skilled in the art. 
   The headend unit  402  further comprises a processor  406  for receiving the digital satellite radio signals from the digital satellite radio receivers  404 . The digital satellite radio signals are provided to the processor  406  via a bus  407 . The processor  406  outputs the digital satellite radio signals to the LAN  441 . 
   Transmission of the digital satellite radio signals on the LAN  441  is based upon a uniform data protocol (UDP). Other protocol types may be used, but the UDP format advantageously allows the processor  406  to broadcast the digital satellite radio signals to the SEBs  445  without having to receive acknowledgments therefrom. Consequently, the headend unit  402  may be considered a dumb terminal. 
   In addition, the headend unit  402  further comprises a video server  430  for providing streaming video to the LAN  441 . The streaming video is also based upon the UDP format. The streaming video advantageously permits passengers to view movies over the LAN  441 , as will be discussed in greater detail below. 
   Depending on the size of the aircraft, passenger seating is preferably divided into passenger seating zones, and each SEB  445  is within a respective passenger seating zone. For example, a narrow-body aircraft may be divided into 8 passenger seating zones. To support the 8 passenger seating zones, a multi-port input/output (I/O) switch  408  interfaces between the processor  406  and the LAN  441 . 
   The multi-port I/O switch  408  may be a 16 port switch, for example, with each port being a dual input/output (I/O) port. The output of the processor  406  providing the digital satellite radio signals is connected to one of the 16 I/O ports. Within the switch  408 , the digital satellite radio signals are routed to 8 other I/O ports, with each I/O port supporting a respective passenger seating zone. If necessary, the remaining ports may be used to support additional passenger seating zones on larger aircraft. 
   In addition, the output of the video server  430  is also connected to a different one of the 16 I/O ports. Within the I/O switch  408 , the streaming video is provided to each of the 8 I/O ports all ready receiving the digital satellite radio signals. Consequently, the LAN  441  provides both the streaming video and the digital satellite radio signals to the SEBs  445  associated therewith. 
   Moreover, another one of the I/O ports may be used as a maintenance port for downloading data to the IFE system  400 . For example, movies may be downloaded to the video server  430  via the maintenance port. A suitable downloading device, such as the illustrated laptop computer  412 , may be used. The maintenance port may also be used for uploading data from the IFE system  400 , such as system diagnostic data or data associated with the video server  430 . Alternatively, one of the I/O ports may be connected to a wireless data link  414 , which may also be used for uploading/downloading data. The wireless data link  414  provides a wireless communications link between the IFE system  400  and a central control network on the ground. The link may use a standard 802.11 protocol or any other suitable protocol. 
   In the illustrated embodiment of an SEB  445  provided in  FIG. 20 , three passengers are supported. More passengers may be supported depending on the size of the aircraft. In particular, the SEB  445  includes a network switch  447  that interfaces with the LAN  441 . The network switch  447  advantageously permits the three passengers to simultaneously access the LAN  441 . Alternatively, the network switch  447  may be a router, as readily appreciated by those skilled in the art. 
   A network switch control processor  448  is connected to the network switch  447  for control thereof. The network switch  447  is considered a smart switch in the sense that it can prevent a passenger from “hacking” onto the LAN  441 . 
   For instance, each passenger has the option of connecting a laptop computer  453  (for viewing the streaming video provided by the video sever  430 ) to an auxiliary output  451  on the SEB  445 . The network switch  447  prevents a passenger from flooding the LAN  441  with an excessive amount of data resulting in the other passengers not being able to receive the digital satellite radio signals or the streaming video. The network switch  447  thus makes the IFE system  400  more secure as compared to the use of a hub or router. 
   In the aircraft, the auxiliary outputs  451  extend to the respective armrests of the passenger seating supported by the SEB  445 . The auxiliary output  451  provides an RJ-45 connector for interfacing with the laptop computer  453 . Processing of the streaming video is based upon the laptop computer  453  executing the appropriate media player software, as readily appreciated by those skilled in the art. 
   Since each SEB  445  supports three passengers, there are three passenger processors  449 . Each passenger processor  449  is used for decoding the digital satellite radio signals. A respective passenger control unit (PCU)  471  is connected to each passenger processor  449 , and permits passenger selection of the digital satellite radio signals to be decoded. 
   Each PCU  471  includes a set of control buttons, such as channel select buttons  460 , volume select buttons  462  and category select buttons  464 , as illustrated in  FIG. 21 . The PCU  471  also includes an alpha-numeric display  466  for displaying a limited amount of text to the passenger. The display  466  may be an LCD, for example. 
   The category select buttons  464  allow the passenger to scroll up or down through all available music categories provided by the digital satellite radio satellite  433 . These categories relate known entertainment categories such as rock, news, jazz, classical, country or decades. Text relating to these categories is displayed to the passenger via the LCD  466 . Alternatively, text may be displayed on a video display unit (VDU)  493  or on a laptop computer  453  connected to an auxiliary output  451 . 
   Once the passenger selects a category, multiple channels relating to the selected category are provided from which the passenger may choose via the channel select buttons  460 . The channel select buttons  460  allow the passenger to scroll up or down through all available audio channels. The volume select buttons  462  allow the passenger to adjust the volume at the headset  470 . In the aircraft, the headset jacks  480  extend to the respective armrests of the passenger seating supported by the SEB  445 . 
   As noted above, the LCD  466  displays a limited amount of text that is initially transmitted as part of the digital satellite radio signals. Additional or supplemental data may be stored in a memory  455  within each SEB  445 . This supplemental data is used to provide enhanced graphics for certain audio channels. For example, if the passenger selects via the PCU  471  a sporting event, such as a football game, then the supplemental data may be a football field showing the names of the two teams in their respective end zones. A football icon may also be displayed on the football field to illustrate who has the ball, and what yard line they are on. In addition, player statistics are provided, and these statistics are updated as the game progresses. 
   To display the supplemental graphical data, a video display unit (VDU)  493  other than the display  466  of the PCU  471  may be used. In this embodiment of the invention, each passenger has a respective seatback video display unit  493  in front of them. The video display unit  493  is also connected to the passenger processor  449  (along with the corresponding PCU  471 ) in the SEB  445 . 
   The IFE system  400  may also include other entertainment sources. For example, the IFE system  400  may include a satellite television (TV) receiver  415  for generating a plurality of TV programming channels. Additional electronic equipment may be necessary for providing the TV programming channels to the LAN  441 , as readily understood by those skilled in the art. 
   Each SEB  445  also comprises a headphone detection circuit  482  connected to a corresponding headphone jack  480  and to a respective passenger processor  449 . The headphone detection circuit  482  sets an audio volume of the digital satellite radio signals to a predefined level when removal of the headphones  470  has been detected. This feature of the invention advantageously prevents a new passenger from damaging their hearing when first listening to the digital satellite radio signals if a previous passenger had the volume turned up to loud. In addition, the headphone detection circuit  482  may be used to detect a failure of the headphones  470 . 
   The headend unit  402  further comprises a public address (PA) circuit  450  so that the pilot and/or the flight attendants can address the passengers. The PA circuit  450  has a keyline input  452  for activating the PA circuit, and an audio input  454 . The PA circuit  450  is connected to the processor  406 . When addressing the passengers, it is necessary for the PA circuit  450  to mute the audio signals being output to the SEBs  445 . Consequently, the audio signals are muted within the I/O switch  408  in response to the keyline input  452  being selected. 
   The audio output from the PA circuit  450  is provided to the SEBs via a path  456  that is separate from the LAN  441 . This configuration requires the passengers to have their headphones  470  plugged-in. Alternatively, the separate path may be connected to an overhead cabin speaker system instead of to the SEBs  445 . Yet another approach for providing the audio to the passengers is to transmit the audio over the LAN  441 . 
   The digital satellite radio signals may also be organized into channel maps defining available audio channels to be selected by each respective PCU  471 . In other words, channel maps may be used to block certain channels. For instance, selected premium channels may be blocked until a payment is made by the passenger. The desired channel maps may be downloaded to the IFE system  400  via the maintenance port of the I/O switch  408  in the headend unit  402 . The memory  455  in each SEB  445  stores the channel maps. 
   The above discussion of the IFE system  400  receiving live audio broadcasts from a satellite  433  is based upon the digital satellite radio receivers  404  being collocated in the headend unit  402 . Another embodiment of the IFE system  500  will now be discussed with reference to  FIGS. 24-26 . This particular embodiment is based upon the digital satellite radio receivers  502  being located in the SEBs  545 . In other words, the digital satellite radio signals are down converted to a baseband signal at the SEBs  545  instead of at the headend unit  502 . 
   The IFE system  500  comprises an antenna  536  for receiving the digital satellite radio signals, a receiver/intermediate frequency (IF) down converter  504  is connected to the antenna  536  for down converting the digital satellite radio signals to an intermediate frequency, and a plurality of SEBs  545  are spaced throughout the aircraft. Each SEB  545  comprises at least one IF tuner  520 . Cabling  541  connects the receiver/IF down converter  504  to the plurality of SEBs  545  for providing the digital satellite radio signals at the intermediate frequency to each IF tuner  520 . The cabling  541  comprises a coaxial cable, for example. 
   For purposes of illustrating this embodiment of the invention, the antenna  536  receives the digital satellite radio signals from an XM radio satellite  533  within the frequency range of 2.33 to 2.34 GHz. The digital satellite radio signals are passed to a first stage RF receiver, i.e., the receiver/IF down converter  504 , for outputting the digital satellite radio signals at an IF of 2.0 MHz, for example. The digital satellite radio signals at the 2.0 MHz IF are passed to an IF distribution unit  506 . 
   The aircraft is divided into passenger seating zones and each IF tuner  520  is within a respective passenger seating zone. The IF distribution unit  506  includes a plurality of outputs for outputting the digital satellite radio signals at the 2.0 MHz IF to the IF tuners  520  within a respective passenger seating zone. The IF distribution unit  506  also amplifiers the digital satellite radio signals for maintaining acceptable signal strength. 
   The illustrated IFE system  500  also includes a video server  530  for providing video channels. The output of the video server  530  is connected to a modulator  532  for modulating the video channels to an intermediate frequency for transmission over the cabling  541 . In lieu of the video server  530  or in addition to it, a satellite TV receiver  515  may be included to receive live TV programming channels. The output of the satellite TV receiver  515  is also connected to an IF down converter  517  so that the programming channels can be transmitted over the cabling  541 . 
   A combiner  508  is used for sending the digital satellite radio signals, the video channels and the programming channels over the cabling  541 . The combiner  508  has a first input for receiving the digital satellite radio signals at the intermediate frequency from the IF distribution unit  506 , and a second input for receiving the video channels from the video server  530 , and a third input for receiving the programming channels from the satellite TV receiver  515 . The combiner  508  has a plurality of outputs connected to the cabling  541  associated with the different passenger seating zones. 
   To down load movies to the video server  530 , a suitable downloading device, such as the illustrated laptop computer  512 , may be used. The laptop computer  512  may also be used for uploading data from the IFE system  500 , such as system diagnostic data or data associated with the video server  530 . Alternatively, a wireless data link  514  may also be used for uploading/downloading data. 
   The headend unit  502  further comprises a public address (PA) circuit  550  so that the pilot and/or the flight attendants can address the passengers. The PA circuit  550  has a PA keyline input  552  for activating the PA circuit, and a PA audio input  554 . The PA circuit  550  is connected to the combiner  508 . When addressing the passengers, it is necessary for the PA circuit  550  to mute the audio signals being output to the SEBs  545 . The audio output from the PA circuit  550  may be provided to the SEBs  545  via the cabling  541  or via a separate path, such as an overhead speaker system, for example. 
   In the illustrated embodiment of an SEB  545  provided in  FIG. 23 , the SEB supports three passengers. In particular, the SEB  545  includes an RF splitter  547  connected to the cabling  541 . The illustrated RF splitter  547  includes 7 outputs. Of the 7 outputs, 3 outputs provide the video channels/programming channels to the respective video/TV tuners  522 , and 3 outputs provide the digital satellite radio signals at the 2.0 MHz IF to the respective IF tuners  520 . 
   The remaining output of the splitter  547  provides the combined video/programming channels and digital satellite radio signals at the 2.0 MHz IF (i.e., they are not split) to an amplifier  542 . The amplifier  542  amplifies the signals before passing them to an RF splitter  547  in an adjacent SEB  545  within the same passenger seating zone. Alternatively, each RF splitter  547  may be directly connected to the cabling  541 . 
   A video display unit (VDU)  593  is connected to each video/TV tuner  522 . The VDU  593  may be a seatback video display unit  493  in front of the passenger. A respective on-screen display device  525  is between each video/TV tuner  522  and a corresponding VDU  593 . The on-screen display device  525  is under the control of the processor  548  in the SEB  545 , and generates text messages so that they may appear on the corresponding VDU  593 . The text messages may be generated by each on-screen display device  525  in lieu of the output of the video/TV tuner  522  or may be overlaid upon the output of the associated tuner. 
   The processor  548  handles communication to and tuning of the video/TV tuners  522  and the IF tuners  520 . The processor  548  also handles operation of the control buttons on the PCUs  571  and the output text to the VDUs  593  via the on-screen display units  525 . A memory  549  is connected to each processor  548 , and serves as a local storage for information specifically relating to its associated SEB  545 . This information may include hardware status information pertaining to each specific PCU  571  and VDU  593  connected to the processor  548 , and the channel map generated by the headend unit  502 . 
   Each PCU  571  is a dual use device because it can operate in a video mode for controlling the video/TV tuner  522  and in an audio mode for controlling the IF tuner  520 . Each SEB  545  also comprises at least one auxiliary output  551  for providing the video channels to at least one external display. The external display may be a laptop computer  553 , for example. 
   The output of each IF tuner  520  performs a D/A conversion for converting the digital output of the tuners to an analog signal suitable for driving a standard headset  570 . There is a corresponding headphone detection circuit  582  connected between an IF tuner  520  and its associated headset jack  580 . The headphone detection circuit  582  allows the processor  548  to set an audio volume of the audio signals to a predefined level when removal of the headphones  570  has been detected. 
   Referring now to  FIG. 24 , another embodiment of the digital satellite radio receivers being located in the SEBs will be discussed. The headend unit  602  is connected to an antenna  636  for receiving the digital satellite radio signals from an XM radio satellite  633 . Instead of transmitting the digital satellite radio signals at the intermediate frequency being transmitted over a cable connected to the SEBs  645 , a leaky coaxial cable  641  is used. A leaky coaxial cable  641  is slotted on its outer conductor for allowing functioning as a signal transmission line and antenna of electromagnetic waves, as readily understood by those skilled in the art. 
   The leaky coaxial cable  641  is connected to the output of the combiner and extends through the aircraft  31 . Each SEB  645  has an antenna  648  connected thereto for receiving transmissions from the leaky coaxial cable  641 . Depending on the bandwidth of the signals that can be transmitted from the leaky coaxial cable  641  to the respective SEBs  645 , the video channels/programming channels may also be provided via the leaky coaxial cable  641 . Alternatively, the combiner  508  may be connected to an RF module and a corresponding antenna(s) for providing the entertainment related data to the SEBs  545  as readily understood by those skilled in the art. 
   Another feature of the present invention is directed to an in-flight entertainment (IFE) system where available space is limited and weight is a concern, as is typical for narrow-body aircraft. Referring now to  FIGS. 27 and 28 , an aircraft IFE system  700  comprising a plurality of SEBs  745  are spaced throughout the aircraft, with each SEB comprising a memory  755  including a shared memory portion  755   a  for storing entertainment related data and an unshared memory portion  755   b . Cabling  741  connects the plurality of SEBs  745  together so that the entertainment related data in the shared memory portion  755   a  of each SEB  745  is available for at least one other SEB. 
   The cabling  741  connects the plurality of SEBs  745  together in a daisy chain configuration. The shared memory portion  755   a  of each SEB  745  may be connected together in a local area network (LAN). The LAN may comprise an Ethernet network, which may be configured by a twisted pair wire, a coaxial cable or a fiber optic cable. 
   The entertainment related data includes a plurality of video programming channels and music (i.e., MP3 files), for example. Instead of having a video server in the headend unit  702  storing the entertainment related data, the data is advantageously stored throughout the aircraft in the shared memory portions  755   a  in each SEB  745 . 
   The entertainment related data in each shared memory portion  755   a  may comprise at least a portion of a video program and/or a plurality of MP3 files. In other words, each video program may be a different movie, for example, and a size of the shared memory portion  755   a  in each SEB  745  may not be sufficient to store the entire movie. Consequently, the movie is divided into sections, and each section is stored in a different SEB  745 . Depending on the size of the shared memory portions  755   a,  3 to 6 movies may be stored throughout the SEBs  745 . When a passenger selects a particular video program, retrieval of the different sections of the movie is transparent to the passenger. 
   The shared memory portions  755   a  in each of the SEBs  745  advantageously provides entertainment related data to the passengers without requiring a dedicated video server. Such a video server would increase the weight of the aircraft, and moreover, would require installation space that may not be available in the headend unit  702 . 
   In fact, one embodiment of the IFE system  700  may be provided without a headend unit  702 . In this particular embodiment, one of the SEBs  745  would function as a master SEB, and the entertainment related data would be loaded through this master SEB to the other SEBs. 
   The size of the memory  755  varies depending on the amount of entertainment related data being stored. For instance, if the entertainment related data includes 3 to 6 movies, a size of the shared memory portion  755   a  may be 100 Mb, for example. The unshared memory portion  755   b  is sized to store data specific to its SEB  745 . Examples of specific data include graphics to be displayed, and an operating system associated with the entertainment related data being shared as network files. An example size of the unshared memory portion  755   b  is 30 Mb. Moreover, the shared and unshared memory portions  755   a ,  755   b  may be configured as separate memories or as a single memory as readily appreciated by those skilled in the art. 
   In another embodiment of the IFE system  700 , the IFE system may include a headend unit  702 . The headend unit  702  includes an input/output (I/O) switch  708  connected to the cabling  741 . The I/O switch  708  includes a maintenance port for downloading the entertainment related data to the IFE system  700 . A suitable downloading device, such as the illustrated laptop computer  712 , may be used. The maintenance port may also be used for uploading data from the IFE system  700 , such as system diagnostic data. Alternatively, one of the I/O ports may be connected to a wireless data link  714 , which may also be used for uploading/downloading data. The wireless data link  714  provides a wireless communications link between the IFE system  700  and a central control network on the ground. The link may use a standard 802.11 protocol or any other suitable protocol. 
   In the illustrated embodiment of an SEB  745  provided in  FIG. 26 , three passengers are supported. More passengers may be supported depending on the size of the aircraft. In particular, the SEB  745  includes a network switch  747  that interfaces with the cabling  741 . The network switch  747  advantageously permits the three passengers to simultaneously access the entertainment related data. 
   A network switch control processor  748  is connected to the network switch  747  for control thereof. The network switch  747  is considered a smart switch in the sense that it can prevent a passenger from “hacking” onto the LAN  741 . The memory  755  is connected to the network switch control processor  748 . 
   Each passenger has the option of connecting a laptop computer  753  to an auxiliary output  751  on the SEB  745  for viewing the video programming channels. The network switch  747  prevents a passenger from flooding the LAN  741  with an excessive amount of data resulting in the other passengers not being able to receive the video programming channels. The network switch  747  thus makes the IFE system  700  more secure as compared to the use of a hub or router. 
   In the aircraft, the auxiliary outputs  751  extend to the respective armrests of the passenger seating supported by the SEB  745 . The auxiliary output  751  provides an RJ-45 connector for interfacing with the laptop computer  753 . Processing of the video programming channels is based upon the laptop computer  753  executing the appropriate media player software, as readily appreciated by those skilled in the art. 
   Since each SEB  745  supports three passengers, there are three passenger processors  749 . Each passenger processor  749  is used for decoding the video programming channels. A respective passenger control unit (PCU)  771  is connected to each passenger processor  749 , and permits passenger selection of the entertainment related data to be decoded. 
   Each PCU  771  includes a set of control buttons, such as channel select buttons and volume select buttons. The PCU  771  may also include an alpha-numeric display for displaying a limited amount of text to the passenger. The display may be an LCD, for example. Volume select buttons allow the passenger to adjust the volume at the headset  770 . In the aircraft, the headset jacks  780  extend to the respective armrests of the passenger seating supported by the SEB  745 . 
   The IFE system  700  may also include other entertainment sources. For example, the illustrated IFE system  700  includes a satellite television (TV) receiver  715  for generating a plurality of TV programming channels. Consequently, other electronic equipment (not shown) is necessary for providing the programming channels to the cabling  741 , as readily understood by those skilled in the art. 
   Each SEB  745  also comprises a headphone detection circuit  782  connected to a corresponding headphone jack  780  and to a respective passenger processor  749 . The headphone detection circuit  782  sets an audio volume of the entertainment related data to a predefined level when removal of the headphones  770  has been detected. 
   The headend unit  702  further comprises a public address (PA) circuit  750  so that the pilot and/or the flight attendants can address the passengers. The PA circuit  750  has a PA keyline input  752  for activating the PA circuit, and a PA audio input  754 . The PA circuit  750  is connected to one of the ports of the I/O switch  708 . When addressing the passengers, it is necessary for the PA circuit  750  to mute the audio signals being output to the SEBs  745 . Consequently, the audio signals are muted within the I/O switch  708  in response to the PA keyline input  752  being selected. 
   The audio output from the PA circuit  750  is provided to the SEBs  745  via a path  756  that is separate from the cabling  741 . Alternatively, the separate path may be connected to an overhead cabin speaker system instead of to the SEBs  745 . Yet another approach for providing the audio to the passengers is to transmit the audio over the cabling  741 . 
   Referring now to  FIGS. 29 and 30 , yet another feature of the present invention is directed to an in-flight entertainment (IFE) system  800  in which portable wireless devices  811  are permitted to operate while the aircraft is in flight. Portable wireless devices  811  include cellular telephones, pagers and personal data assistants that receive e-mail messages, for example. The cellular telephones may operate according to GSM, TDMA, CDMA, FDMA, AMPS or other standard or proprietary communications protocol. 
   The aircraft IFE system  800  comprises an antenna  836 , an external communications transceiver  804  connected to the antenna for communicating external the aircraft, and a plurality of seat electronic boxes (SEBs)  845  spaced throughout the aircraft. At least one of the SEBs  845  comprises an internal communications transceiver  806  for communicating with a portable wireless device  811  carried by a passenger. 
   Each portable wireless device  811  is selectively operable in a normal power mode and a low power mode, with the low power mode being selected for communicating with the internal communications transceiver  806 . Cabling  841  connects the external communications transceiver  804  to the plurality of SEBs  845  so that the portable wireless devices  811  communicate external the aircraft while operating in the low power mode. 
   The low power mode of each portable wireless device  811  may be selected by the passenger, or by the internal communications transceiver  806 . The illustrated portable wireless devices  811  include a normal power mode module  813  and a low power mode module  815  for controlling the transmit power of the transmitter  817 . For example, the transmit power for a cellular telephone operating in a normal power mode may be 600 watts, whereas the transmit power for a cellular telephone operating in a low power mode may be 200 watts. Of course, the actual transmit power in the low power mode will be selected ahead of time so that operation of the cellular telephone will not interfere with the aircraft electronics. 
   The internal communications transceiver  806  in each SEB  845  may be considered an access point, and is able to communicate with more than one portable wireless device  811  at a same time. Communications between the external communications transceiver  804  and the internal communications transceiver  806  is based upon the Ethernet. Wireless communications between the internal communications transceiver  806  and the portable wireless device  811  is based upon the 802.11 protocol, whereas the wired communications between the external and internal communications transceivers  804 ,  806  is based upon the 802.3 protocol. Of course, other acceptable protocols may be used, as readily appreciated by those skilled in the art. For instance, the internal communications transceiver  806  may comprise an infrared transceiver for communicating with the portable wireless device  811 . 
   Each internal communications transceiver  806  is connected to an antenna  812 . Likewise, each portable wireless device  811  includes an antenna  814 . The internal communications transceiver  806  communications with each portable wireless device  811  based upon a temporary address. To establish a communications channel with a portable wireless device  811 , the internal communications transceiver  806  may broadcast a low power mode signal for placing any portable wireless devices  811  within range in the low power mode. This broadcast may be continuous or intermittent throughout the flight. 
   If the portable wireless devices  811  cannot be placed in the low power mode, then the internal communications transceiver  806  will not establish communications with the portable wireless device  811 . Confirmation that the portable wireless device  811  is operating in the low power mode may be confirmed by the internal communications transceiver  806  or confirmation may be provided by the portable wireless device  811  itself. 
   The internal communications transceiver  806  includes a signal strength measurement circuit  810  for measuring the strength of the signals transmitted from a portable wireless device  811  operating in close proximity. Even if the portable wireless device  811  provides confirmation that it is operating in the low power mode, the signal strength measurement circuit  810  may still measure the strength of the transmitted signal as a precaution to insure that the aircraft electronics will not be affected. This measurement may be periodically performed throughout the communications session. 
   The illustrated external communications transceiver  804  is carried by a headend unit  802 . The headend unit  802  further carries an entertainment source  820  connected to the cabling  841  for providing entertainment related data to the passengers. If the entertainment related data is in a digital format, then the same cabling  841  is used. Otherwise, a separate cable is necessary if the entertainment related data is in an analog format. At least one video display unit (VDU)  893  is connected to each SEB  845 , and a respective passenger control unit (PCU)  871  is associated with-each of the VDUs. The entertainment source  820  may comprise a direct broadcast satellite (DBS) receiver, a terrestrial television (TV) receiver, or a satellite radio receiver for receiving radio signals, for example. 
   As readily appreciated by those skilled in the art, the present invention may also be directed to an aircraft communication system that does not provide entertainment related data. In other words, such an aircraft communications system comprises an antenna  836 , and an external communications transceiver  804  connected to the antenna for communicating external the aircraft. At least one internal communications transceiver  806  establishes a communications link between the external communications transceiver  804  and a portable wireless device  811  carried by a passenger internal to the aircraft. In this embodiment, the internal communications transceiver  806  commands the portable wireless device  811  into a low power mode. 
   A method for operating portable wireless devices  811  with an aircraft IFE system  800  is provided by the flow chart illustrated in  FIG. 28 . As discussed above, each portable wireless device is selectively operable in a normal power mode and a low power mode. The IFE system comprises an antenna  836 , an external communications transceiver  804  connected to the antenna for communicating external the aircraft, and a plurality of SEBs  845  spaced throughout the aircraft. Each SEB  845  comprises an internal communications transceiver  806 , and cabling  841  connecting the external communications transceiver  804  to the plurality of SEBs. 
   From the start (Block  860 ), the method comprises selectively placing each portable wireless device  811  in the low power mode in Block  862  for communicating with the internal communications transceiver  806  in a corresponding SEB  845 . The internal communications transceiver  806  confirms that the portable wireless device  811  is in the low power mode at Block  864 . A communications session is established over the cabling  841  at Block  866  between the internal communications transceiver  806  and the external communications transceiver  804  so that the portable wireless device  811  communicates external the aircraft while operating in the low power mode. The method ends at Block  868 . 
   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 in-flight entertainment system are disclosed in copending patent applications filed concurrently herewith and assigned to the assignee of the present invention and are entitled AIRCRAFT IN-FLIGHT ENTERTAINMENT SYSTEM INCLUDING LOW POWER TRANSCEIVERS AND ASSOCIATED METHODS, Ser. No. 11/023,758; AIRCRAFT IN-FLIGHT ENTERTAINMENT SYSTEM INCLUDING DIGITAL RADIO SERVICE AND ASSOCIATED METHODS, Ser. No. 11/024,072; AIRCRAFT IN-FLIGHT ENTERTAINMENT SYSTEM WITH A DISTRIBUTED MEMORY AND ASSOCIATED METHODS, Ser. No. 11/023,891; AIRCRAFT IN-FLIGHT ENTERTAINMENT SYSTEM INCLUDING A DISTRIBUTED DIGITAL RADIO SERVICE AND ASSOCIATED METHODS, Ser. No. 11/023,728; and AREA ENTERTAINMENT SYSTEM INCLUDING DIGITAL RADIO SERVICE AND ASSOCIATED METHODS, Ser. No. 11/023,730, the entire disclosures of which are incorporated herein in their entirety by reference. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are intended to be included within the scope of the appended claims.