Abstract:
Line or shop replaceable units (LRUs or SRUs) of a vehicle entertainment system are programmed as microservers to receive and carry out requests for testing the LRUs/SRUs from a browser connected to the LRUs/SRUs over a communications network of the vehicle entertainment system. Test results are transmitted back to the browser for display. The browser may be part of the vehicle entertainment system or remotely connected to the communications network of the vehicle entertainment system. Hyper-Text Transfer Protocol (HTTP) is used as the protocol for transporting the requests and the execution results over the communications network, and so, the programming of the LRUs and the SRUs may be achieved with a standard HTTP server program and the browser may be any HTTP-compliant browser such as Netscape Navigator™ and Internet Explorer™.

Description:
REFERENCE TO RELATED APPLICATION 
     This application is related to, and being filed concurrently with, an application by Douglas Infiesto, David Frankenbach, and Joe Winston, entitled “Vehicle Entertainment System Having Seat Controller Cards Programmed to Operate as Both Browser and Server,” the contents of which are incorporated herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a vehicle entertainment system, and more particularly, to a vehicle entertainment system in which built-in test environment servers are provided for replaceable units of the vehicle entertainment system to locally manage remote test requests that are transmitted in compliance with HyperText Transport Protocol (HTTP). 
     2. Description of the Related Art 
     Hypertext documents are computer files containing text and images with links, more commonly referred to as hyperlinks, to other hypertext documents. The coding language that is used to create hypertext documents is known as HyperText Markup Language (HTML). The protocol for moving hypertext documents across an interconnected network of computers, e.g., across the Internet or an intranet, is known as HyperText Transport Protocol (HTTP). This protocol requires an HTTP client program on one end and an HTTP server program on the other end. The HTTP client program is known as a browser. It is the software that displays hypertext documents and manages inputs thereto. The two most popular types of browsers are Netscape Navigator™ and Internet Explorer™. The communications protocol that is used in the interconnected network of computers, e.g., the Internet or intranet, is Transmission Control Protocol/Internet Protocol (TCP/IP). 
     Each hypertext document has an address associated therewith. This address is known as a Uniform Resource Locator (URL). Generally, a user requests hypertext documents using the browser by either typing in the URL, or by maneuvering a cursor to a position on the displayed hypertext document that corresponds to a hyperlink to the URL and actuating the mouse button. The latter method is commonly referred to simply as “clicking on the hot-spot” or “clicking on the hyperlink.” When the user types in the URL or clicks on the hyperlink, the browser transmits the URL corresponding to the requested hypertext document to an HTTP server computer in which the requested hypertext document resides. The server computer retrieves this document and transmits it back to the browser. 
     Although the URL is typically associated with a hypertext document, it may be associated with an executable program instead. If a URL that is associated with an executable program is specified by a browser, the server computer in which the executable program resides executes the program using any input data received from the browser, and the output of the program is transmitted back to the browser, typically in the form of a hypertext document. 
     An in-flight entertainment (IFE) system providing Internet or intranet access is proposed in co-pending U.S. patent application Ser. No. 09/085,180, filed May 26, 1998, entitled “Passenger Entertainment System, Method and Article of Manufacture Having Improved Area Distribution Equipment,” the contents of which are incorporated by reference herein. In this system, client computing capabilities are provided at every seat by equipping each seat with an input device (a passenger control unit and a touch screen), an output device (a display unit), and a processor programmed with a browser. The connection to the Internet is provided by a satellite uplink and downlink. The system may also function as an airborne intranet to permit the passenger to select and control product ordering services, passenger services, and entertainment and communications services without connecting to the Internet. 
     When providing either Internet or intranet access, the above-described system employs a system file server, which is referred to as a cabin file server (CFS) in an IFE system. In the case of Internet access, the CFS functions as a proxy server to manage the connections to other server computers over the Internet. In the case of intranet access, the CFS functions as an HTTP server computer to directly manage requests for hypertext documents and program executions. 
     In the above-described IFE system, although the Internet or intranet access is available, the testing of the components of the IFE system is not carried out using the Internet or intranet. Rather, a built-in test environment (BITE) tester, which is specially configured to carry out the testing operations on the IFE system, is provided. As a result, none of the advantages of the Internet or intranet access is realized by the IFE system during testing operations. For example, in the above-described IFE system, the operator interface for controlling the BITE tester is customized to the special configurations of the BITE tester and is accessible only at a terminal that is directly interfaced with the BITE tester. The operator interface cannot be accessed from other locations using a standard graphical user interface, such as a browser, even though they are networked with the BITE tester over the Internet or intranet. 
     A centralized control of the testing operations at the BITE tester is undesirable for two additional reasons. First, when several test requests reach the BITE tester at about the same time, the requests will have to be queued, causing undesirable delays. Second, if the BITE tester is down for maintenance or repair, the BITE tester will be unable to process any pending test requests until the maintenance or repair has been completed. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide a vehicle entertainment system in which testing of line or shop replaceable units (LRUs or SRUs) is controlled over the Internet or intranet. 
     Another object of the invention is to provide a vehicle entertainment system in which testing of LRUs and SRUs is decentralized. 
     Still another object of the invention is to provide an LRU or SRU for a vehicle entertainment system that is programmed to test itself in response to a test request received over a communications network of the vehicle entertainment system. 
     Yet another object of the invention is to provide a method of testing LRUs and SRUs over the Internet or intranet from a remote location. 
     The above and other objects of the invention are achieved with a vehicle entertainment system having LRUs and SRUs that are programmed as microservers to receive and carry out test requests that are transmitted from a browser connected to the LRUs/SRUs over a communications network of the vehicle entertainment system. Test results are transmitted back to the browser over the communications network for display. The browser may be a part of the vehicle entertainment system or connected to the communications network of the vehicle entertainment system from a remote location. Hyper-Text Transfer Protocol (HTTP) is used as the protocol for transporting the requests and the execution results over the communications network, and so, the programming of the LRUs and SRUs may be achieved with a standard HTTP server program and the browser may be any HTTP browser such as Netscape Navigator™ and Internet Explorer™. 
     Additional objects, features and advantages of the invention will be set forth in the description of preferred embodiments which follows. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The various features and advantages of the present invention may be more readily understood with reference to the following detailed description taken in conjunction with the accompanying drawings, and in which: 
     FIG. 1 is a block diagram of a networked IFE system having a plurality of line and shop replaceable units; 
     FIG. 2 illustrates software components of a system file server and a seat controller card of the IFE system according to FIG. 1; 
     FIG. 3 is a block diagram of a seat controller card of the networked IFE system; and 
     FIG. 4 is a diagram illustrating a hypertext document and one or more executable programs that are stored locally in a line or shop replaceable unit of the networked IFE system. 
    
    
     The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate presently preferred exemplary embodiments of the invention, and, together with the general description given above and the detailed description of the preferred embodiments given below, serve to explain the principles of the invention. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the description provided below, a description of some of the details of a vehicle entertainment system has been omitted for clarity. Such details may be found in the copending U.S. patent application Ser. No. 09/085,180. Further, although an aircraft is depicted, the system according to the invention may be implemented in any vehicle having a passenger entertainment system. Some of the examples include buses, boats, trains, and jet foils. 
     FIG. 1 is a block diagram of an in-flight entertainment (IFE) system  10  operating in an intranet environment. The intranet server computer includes a cabin file server (CFS)  20  and the client computers include seat controller cards (SCCs)  70  each having a processor  71  (see FIG. 3) that is programmed with a browser and connected to a display  81  and a touch screen  82 . Hypertext documents are displayed on the display  81  and a passenger provides inputs using the touch screen  82 . A RF cable network  55  connect the CFS  20  to the SCCs  70 . 
     The CFS  20  may also operate as a client computer when operating in the Internet environment or when one or more of the SCCs  70  are programmed as an HTTP server. For this purpose, a primary access terminal  15  is interfaced with the CFS  20  and the processor of the CFS  20  is programmed with a browser. The primary access terminal  15  typically includes a display and an input device, usually a keyboard and a mouse (or a touch screen). Hypertext documents are displayed on the display of the primary access terminal  15  and a system operator provides inputs using the input device. 
     In the IFE system  10 , a plurality of micronets are configured within the intranet environment. A micronet is illustrated in FIG.  2 . It constitutes an HTTP connection between a microserver  91 , which operates as the HTTP server program, and a browser  92 , which operates as the HTTP client program. The intranet, by contrast, constitutes an HTTP connection between the CFS  20 , which operates as the intranet server, and the browser  92 . The communications protocol for both the intranet and the micronet is TCP/IP. 
     The microserver  91  and the browser  92  are two software components of the SCC  70 . The microserver  91  constitutes a processor  71  programmed with an HTTP server program and the browser  92  constitutes the processor  71  running an HTTP browser program such as Netscape Navigator™ and Internet Explorer™. The microserver  91  and the browser  92  are preferably stored in a random access memory (RAM)  72   a.    
     The other software components of the SCC  70  include a core application  94  and low-level drivers  95 . The core application  94  includes an operating system for the SCC  70  and an application software for managing the low-level drivers  95 . The low-level drivers  95  control the hardware components of the SCC  70  and external equipment under control of the passenger, such as overhead lights, headphones, attendant call switch, etc. The core application  94  and the low-level drivers are stored in a flash memory  72   b.    
     The RAM  72   a  and the flash memory  72   b  are represented as a memory  72  in FIG.  3 . The RAM  72   a  further stores hypertext documents and executable programs that are managed by the microserver  91 . They include the home page of the microserver  91  with the URL “scc.com/main.htm” and all other hypertext documents and executable programs having the URL “scc.com” as the root address. Some example of such hypertext documents and executable programs are illustrated in FIG.  4 . 
     FIG. 1 also illustrates a video modulator  30 , a passenger entertainment system controller (PESC)  40 , and an area distribution box  50 . The video modulator  30  is a device that receives multiple RF inputs and modulates the multiple RF inputs into a single RF signal having multiple RF channels. Only a single input from the CFS  20  is shown in FIG. 1 for clarity. The video modulator  30  actually receives other inputs from other devices, such as video cassette players (not shown) and a media file server (not shown). The multi-channel RF signal is supplied to the PESC  40  and the area distribution box  50 , and the area distribution box  50  distributes the multi-channel RF signal to the SCCs  70  over the RF cable network  55 . A plurality of attenuators and amplifiers (not shown) are arranged in the RF cable network  55  to automatically optimize signal quality under software control. Other functions of the PESC  40  and the area distribution box  50  are described in the co-pending U.S. patent application Ser. No. 09/085,180 and are omitted herein. 
     At the SCCs  70 , a tuner  73  (see FIG. 3) is used to extract a desired channel from the multi-channel RF signal and the extracted signal is either demodulated using an analog demodulator  74  or a QAM demodulator  75 . The demodulated output is supplied to a video card  76  which controls the display  81  to display the demodulated output. In addition to the RF cable network  55 , a token passing bus network  56  using RS-485 protocol, known as ARCNET, is used to pass control signals between the CFS  20  and the SCCs  70 . The ARCNET network  56  is illustrated in FIG. 1 in dotted lines. Through this network, the CFS  20  informs the SCC  70  of the RF channel to which it should tune. This network  56  is also used to transmit browser requests from the SCC  70  to the CFS  20 . 
     Line replaceable units (LRUs) of the vehicle entertainment system  10  comprise the PESC  40  and the area distribution box  50 , and shop replaceable units (SRUs) of the vehicle entertainment system  10  comprise the CFS  20  and the SCCs  70 . Other LRUs and SRUs, such as audio-visual units, are omitted in FIG.  1  and this description for clarity. In the present invention, each LRU/SRU includes a memory and a processor. The memory of the LRU/SRU contains an executable program having a series of program instructions for testing that LRU/SRU. FIG. 4 shows some examples. The memory of the SCC  70  contains executable programs for testing the display (video), headphones (audio), overhead lights, and the tuner. The memory of the CFS  20  contains therein executable programs for testing the download card and the system clock. The memory of the PESC  40  and the area distribution box  50  contains executable programs for running a diagnostic check of all of the hardware components. The memory of the LRU/SRU further contains a hypertext document that includes a hyperlink to the executable program or programs. This hypertext document is illustrated in FIG. 4 as “cfs.com/test.htm,” “pesc.com/test.htm,” “adb.com/test.htm,” and “scc.com/test.htm” for the CFS  20 , the PESC  40 , the area distribution box  50 , and the SCC  70 , respectively. 
     The processor for the LRU/SRU is programmed with an HTTP server program, i.e., as a microserver, and locally manages any test requests it receives over the ARCNET network  56 . This microserver operates as the built-in test environment server for the LRU/SRU. Typically, a test request is initiated using an HTTP browser displayed on the primary access terminal  15 . For example, if the system operator desires to run a diagnostic test of the area distribution box  50 , the system operator inputs into the browser a URL corresponding to testing of the area distribution box, i.e., “adb.com/test.htm.” The browser of the CFS  20  transmits a request for this URL to the area distribution box  50 . Since the area distribution box  50  is programmed as a microserver, it is able to receive this request, retrieve this hypertext document from its memory, and deliver the retrieved hypertext document to the primary access terminal  15 . As a result, the hypertext document “adb.com/test.htm” is displayed on the primary access terminal  15 . 
     Then, the system operator clicks on the hyperlink “test” (or touches the screen at that location if a touch screen is used) to request the diagnostic test. The browser of the CFS  20  transmits a request for the corresponding URL “adb.com/cgi/test.exe” to the area distribution box  50 , which retrieves the executable program, executes it, and returns the execution results to the requestor in the form of a hypertext document. The testing of an LRU/SRU may be initiated using the HTTP browser displayed on the primacy access terminal  15  as illustrated above or it may be initiated from any of the SCCs  70  using the browser programmed therein. 
     Although the IFE system  10  of FIG. 1 is illustrated as operating in an intranet environment, it may be configured to also have access to the Internet by way of a satellite uplink and downlink in the manner shown in the co-pending U.S. patent application Ser. No. 09/085,180. In such a system, the CFS  20  operates as a proxy server when a URL that is not part of the intranet or the micronet is accessed, e.g., URL that does not have the root address “scc.com” or the root address “cfs.com.” In addition, the testing of an LRU/SRU may be initiated from a remote location, e.g., from a computer that is connected to the Internet and to the communication network of the vehicle entertainment system  10  over the satellite uplink and downlink. 
     A description of a single SCC  70  and a single micronet resident in the SCC  70  has been provided above for clarity. The description of the single SCC  70  and its respective micronet is, however, representative of all other SCCs  70  of the IFE system  10 . When all of the SCCs  70  are considered, the resulting IFE system  10  will include a plurality of micronets interconnected over the RF cable and ARCNET networks  55 ,  56 . Also, each SCC  70  will have its own unique address. The URLs of the different SCCs  70  may be distinguished from one another by using a numerical suffix “###” to form the address “scc###.com.” 
     While particular embodiments according to the invention have been illustrated and described above, it will be clear that the invention can take a variety of forms and embodiments within the scope of the appended claims.