Multicast downloading of software and data modules and their compatibility requirements

Abstract

A system for downloading different versions of software or data modules into a plurality of terminals having different compatibility interfaces includes an authoring component for generating the different module versions, a downloading source including a descriptor table which associates each module version with a list of compatibility requirements needed to download the module, and a plurality of terminals coupled to the downloading source. The downloading source transmits the descriptor table to each terminal and also continuously transmits the modules over the network. Each terminal extracts the descriptor table and, based on a match between an entry in the descriptor table and an internally stored table, determines which version of a particular module should be downloaded. The system avoids the need for two-way communication between each terminal and the downloading source.

1 . A system for downloading information, comprising: 
 a downloading source comprising a plurality of different modules each corresponding to a different set of terminal compatibility requirements which must be satisfied in order for the module to be downloaded by a terminal, a module descriptor table which associates each of the plurality of different modules with a set of descriptors which describe the different set of compatibility requirements, and means for transmitting the module descriptor table and the plurality of different modules over a network; and    a plurality of terminals each configured to receive the module descriptor table and the plurality of different modules transmitted from the downloading source, each terminal comprising means for extracting one or more sets of descriptors from the module descriptor table, finding a match between the one or more sets of descriptors and a terminal table which defines compatibility interfaces of the terminal, and downloading one of the plurality of modules associated with the matched set of descriptors.    
     
     
         2 . The system of  claim 1 , wherein at least one of the plurality of different modules is compatible with one of the plurality of terminals but is not compatible with the others.  
     
     
         3 . The system of  claim 1 , wherein each of the plurality of different modules comprises a different version of a common application program which is to be executed in one or more of the plurality of terminals.  
     
     
         4 . The system of  claim 1 , wherein each of the plurality of different modules comprises a different version of a common operating system which is to be executed in one or more of the plurality of terminals.  
     
     
         5 . The system of  claim 1 , wherein the transmitting source comprises a headend in a cable television network including means for broadcasting the module descriptor table over the cable television network, and wherein each of the plurality of terminals comprises a home communications terminal (HCT) coupled to the cable television network.  
     
     
         6 . The system of  claim 1 , wherein the module descriptor table comprises a plurality of comparison indicators, each comparison indicator comprising an operator selected from the set consisting of “equal to”, “greater than or equal to”, and “don't care, and wherein each terminal finds the match by applying one of the comparison indicators to one of the plurality of descriptors and to an entry in the terminal table.  
     
     
         7 . The system of  claim 1 , wherein one of the descriptors in the module descriptor table indicates a terminal hardware manufacturer in relation to an entry in the terminal table of each of the plurality of terminals.  
     
     
         8 . The system of  claim 1 , wherein one of the descriptors in the module descriptor table indicates an operating system version number in relation to an entry in the terminal table of each of the plurality of terminals.  
     
     
         9 . The system of  claim 1 , wherein one of the descriptors in the module descriptor table indicates an amount of memory in relation to an entry in the terminal table of each of the plurality of terminals.  
     
     
         10 . The system of  claim 1 , wherein at least one of the plurality of terminals extracts the transmitted module descriptor table after booting up and, responsive to a determination that a more recent version of an operating system is included in the transmitted module descriptor table, downloads one of the plurality of modules corresponding to the more recent version of the operating system.  
     
     
         11 . The system of  claim 1 , wherein the terminal table comprises a first entry indicating the hardware model number of the terminal and a second entry indicating the operating system version number of the terminal, and wherein each of the plurality of terminals compares descriptors from the transmitted module descriptor table with the first and second entries to find the match.  
     
     
         12 . The system of  claim 1 , wherein each of the plurality of terminals extracts one or more sets of descriptors from the module descriptor table in response to selection of an application program at the terminal.  
     
     
         13 . A terminal compatible with a broadcast network, comprising: 
 a terminal table comprising one or more fields which define compatibility interfaces of the terminal;    means for receiving from the network a table of entries each of which associates one of a plurality of downloadable modules with a plurality of terminal compatibility interfaces, comparing one of the fields in the terminal table with one of the entries in the table received from the network and, responsive to a determination that a match exists, downloading the one downloadable module corresponding to the matched entry.    
     
     
         14 . The terminal according to  claim 13 , wherein the one or more fields of the terminal table comprise a hardware manufacturer model number and an operating system version number.  
     
     
         15 . The terminal according to  claim 13 , wherein the one or more fields of the terminal table comprise a memory capacity of the terminal.  
     
     
         16 . The terminal according to  claim 13 , wherein the terminal comprises a home communication terminal (HCT) which is compatible with a subscription television network, and wherein the terminal downloads the one downloadable module over the subscription television network.  
     
     
         17 . The terminal according to  claim 13 , wherein the table of entries comprises a plurality of comparison indicators, each comparison indicator comprising an operator selected from the set consisting of “equal to”, “greater than”, and “don't care”, and wherein the terminal finds the match by applying one of the comparison indicators to one of the fields in the terminal table and to one of the entries in the received table.  
     
     
         18 . The terminal according to  claim 13 , wherein the terminal receives the transmitted table after booting up and, responsive to a determination that a more recent version of an operating system is included in the received table, downloads one of the plurality of modules corresponding to the more recent version of the operating system.  
     
     
         19 . The terminal according to  claim 13 , wherein the downloaded module comprises an application program which is subsequently executed in the terminal.  
     
     
         20 . The terminal according to  claim 13 , wherein the terminal downloads the one downloadable module corresponding to the matched entry from a location determined by data contained in the table of entries received from the network.  
     
     
         21 . A method of downloading a module across a network, comprising the steps of: 
 (1) providing a table which associates each of a plurality of downloadable modules with a plurality of compatibility descriptors, each compatibility descriptor indicating a terminal compatibility required in order to download the associated downloadable module;    (2) transmitting the table to a plurality of terminals in the network;    (3) receiving the transmitted table in one of the plurality of terminals; and    (4) comparing an entry in the table received in step (3) with a terminal table identifying terminal compatibilities and, responsive to a determination that a module can be downloaded based on the comparison, downloading the module over the network.    
     
     
         22 . The method of  claim 21 , wherein step (4) comprises the step of comparing an entry in the received table with a hardware identifier in the terminal table and with a software identifier in the terminal table.  
     
     
         23 . The method of  claim 21 , wherein step (4) comprises the step of downloading the module from a location determined by data contained in the table transmitted in step (2).