ΛD-IIOC FI1-K DKMVK Y SYSTEM AND METHOD
KACKfiROUND
The preseπl invention t elates generally to data disu ihution systems and methods, ami more paitieulatly. to ad-hoe file delivery systems and methods Ionise with a one way data distribution system that distributes data files to person l computers. Che assignee of the present invention has developed a satellite based one way data distribution system thai is used ιo distnhuie data from l oiiicnt piovidurs to client personal computers by way of a satellite. Certain clients require downloading of data files on a daily or weekly basts, for example, which may be deliveied unscheduled limes. The present invention addresses the need lor a deliver) service thai delivers requested files on an ad-hw basis according to predefined tune periods.
II would be an improvement (o hav ad-hoc file delivery systems and methods for use with a one way data distribution system thai distributes data files to personal computers.
SUMMARY OF THE INVENTION
The present invention provides for ad-hoc file delivery systems and methods (service) for use with a data disuibution system thai delivers files from a content provider to one or more ehent personal computers. Λ server receives one or more files transmitted from the content provider that contains a request tor delivery in one or more prescribed tune deiivety periods A priority-based service queue stores the one or more file:, prior in transmission The files may be Moral in a manner that corresponds to the requested time delivery period. A broadcast server retrieves the one or more files from the service queue and transmits them on one of a number of available broadcast channels to the one or more client personal computers.
The ad-hoc file delivery system and method provides for a non-scheduled file delivery service that delivers files to requested locations within one or more prescribed periods. Any suitable delivery time period may be employed. For example, exemplary periods include two hour, four hour, eight hour, and twenty-four hour periods. In addition, there is a best effort service that delivers the file on a best-effort basis not to exceed seven days. The ad-hoc delivery systems and methods are implemented such that a content provider submits content (one or more files) to the network operations center for delivery and requests delivery within one of the prescribed time periods. The content is submitted to a (file transfer protocol) server at the network operations center, and after complete receipt, the content is retrieved from the server and placed into a priori ty- based queue for transmission. The priorities are assigned according the delivery time that is requested by the client.
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, wherein like reference numerals designate like structural elements, and in which:
Fig. 1 illustrates an exemplary data distribution system in which ad-hoc delivery service in accordance with the principles of the present invention is used; Fig. 2 illustrates an exemplary ad-hoc delivery method in accordance with the principles of the present invention;
Fig. 3 illustrates ad-hoc service channel management; Fig. 4 illustrates an exemplary service data flow diagram; and Fig. 5 is a flow diagram illustrating an exemplary embodiment of the ad-hoc file delivery service.
DETAILED DESCRIPTION
Referring to the drawing figures, Fig. 1 illustrates an exemplary data distribution system 10, illustrated as a satellite broadcast data distribution system 10. in which ad-hoc delivery method 30 or service in accordance with the principles of the present invention is used. The exemplary system 10 is designed to distribute data (content) derived from one or more content providers 1 1 by way of a satellite 14 to client personal computers 16. The system 10 uses Internet protocol (IP) addressing to distribute the data to the personal computers 16.
The system 10 comprises a network operations center 13 that includes a data broadcast subsystem (DBS) 21, a subscriber management subsystem (SMS) 22, a network management subsystem (NMS) 23, and a content management subsystem (CMS) 24. One or more content providers 11 communicate by way of a direct line 12a or the Internet 12, for example, to the network operations center 13. The network operations center 13 communicates by way of the satellite 14 to the client personal computers 16. The client personal computers 16 interface to the satellite 14 using satellite receiver PC cards (not shown) disposed in the client personal computers 16. Alternatively, the client personal computers 16 are connected to a local area network 17 and interface to the satellite 14 using a PC card disposed in a server computer 15 coupled to the local area network. The client personal computers 16 are also coupled by way of a modem 18 to the network operations center 13. The modem 18 provides a low-rate return path that is used to transmit requests from the client personal computers 16 to the network operations center 13 in order to download data derived from the content providers 11.
Each of the client personal computers 16 includes software that interfaces to the network operations center 13 and the content providers 1 1. The software is used to browse the Internet 12. send requests for data, control data download sessions, schedule delivery of data, and download streaming audio, video and data to the client personal computers 16in real time, for example.
The system 10 and the software cooperate to establish a virtual private multicast network between the content providers 1 1 and the client personal computers 16. The system 10 and the software cooperate to provide managed electronic data delivery to multiple client personal computers 16. The system 10 and the software cooperate to provide both video and data download services with high efficiency.
Referring now to Fig. 2, it illustrates an exemplary ad-hoc file delivery system 20 and service 30 in accordance with the principles of the present invention. A content provider 1 1 delivers (transmits) their content (data file 52) to a server 25, such as an ftp (file transfer protocol) server 25, for example, which is loaded into a pre-established directory 31 for that provider 1 1. In particular, the content provider 1 1 delivers the file 52 into an ad-hoc delivery sub-directory 32. The sub-directory 32 may contain folders for each of the response times. File delivery may be accomplished using a content submission utility, for example. The content submission utility may be a web-based application that provides a tool to submit content to the server 25 and which may include a series of screens, menus and/or dialog boxes that take the user through the submission process.
A content acquisition management server (CAMS) 26 moves the content from the ftp server 25 into an ad-hoc directory 34 of a service queue 33 associated with the response time (illustrated by the dashed arrow). The content acquisition management server 26 monitors the directories 34 of the service queue 33, and if a file 52 appears within one of the service sub-directories 34 (e.g., <2 hour ad-hoc, etc.), the CAMS server 26 opens a session 42 (Fig. 3) on a multicast server 35 and begins transmission of the file 52 on one of a number of available multicast channels. One of the key elements of the ad-hoc service 30 is the use of multiple channels to serve the service queue 33. Multiple channels are necessary to permit different rates of transmission, yet still preserve total service throughput. Fig. 3 illustrates this concept.
More particularly, Fig. 3 illustrates ad-hoc service channel management implemented in the ad-hoc file delivery service 30 provided by the present invention. Fig. 3 shows multiple conditional access (CA) channels 41 serving the service queue 33. The service queue 33 detects that a file 52 has arrived that requires <2 hour ad-hoc delivery. This is considered a first priority and is placed at the bottom of a Priority 1 queue 34 (<2 hour ad-hoc delivery) as shown in Fig. 3. If no other Priority 1 files 52 are ahead of it, the service queue 33 looks for an available channel 41. If one is available, a multicast session 42 is opened on that channel 41 and the file 52 is broadcast using a multicast server 27 and a broadcast queue 36.
On the client side, each site subscribing to the ad-hoc delivery service 30 is entitled to receive ad-hoc conditional access services. The CyberStar announcement stream announces the multicast stream address that is used by the channel 41 , and together with a CyberStar™ catalog that functions to describe the schedule, recipient list, services, and entitlements for an individual site, the client can filter the data destined for that site.
Another aspect of the ad-hoc delivery system 20 and service 30 is the management of reliable delivery. Three types of reliable broadcast are provided. including single broadcast, reliable broadcast (i.e., a three times carousel), and reliable with rain-fade mitigation (Fig. 3). The service queue 33 handles the single broadcast and reliable broadcast by replicating the transmission within the data broadcast network (DBN) 21. Managing the rain-fade mitigation, however, requires special processing. This is accomplished using a separate rain fade delay queue 37 used by the multicast server 27. In particular, to provide rain-fade mitigation, the file 52 is broadcast, then delayed a minimum of about twenty minutes, then returned to the service queue and broadcast a second time. This significantly reduces the impacts of rain-fades on the delivery of the files 52.
Referring now to Fig. 4, it shows the data flow associated with the ad-hoc delivery service 30. Fig. 4 illustrates the detailed processes used in the ad-hoc delivery service 30. These processes include a receive file process 51 , a process file process 53. a process queue process 58, a broadcast files process 59, a monitor queue process 56, and a process queue status requests process 55.
The receive file process 51 detects the receipt of a file 52 in a content provider's directory 31. Upon reading the file management information contained in the file 52, the file 52 is placed into the appropriate folder and an alarm or alert is sent to the process file process 53.
The process file process 53 receives the alarm or alert from the receive file process 51 and moves the file 52 from the content provider folder within the ftp data into an appropriate ad-hoc folder on the CAMS server 26. The particular folder is determined by the priority of the file 52. Priority 1 files 52 represent the highest priority for transmission and priority 4 represents the lowest priority. Within each priority folder, the files 52 are arranged in time-of-arrival order (i.e., first-come, first- served).
The process queue process 58 functions to prioritize and prepare the appropriate data for broadcast. The broadcast files process 59 functions to broadcast the files 52 over the available channels. The monitor queue process 56 functions to monitor the service, broadcast and rain fade delay queues 33, 36, 37 (Fig. 2) to monitor the integrity and status of the queues 33, 36, 37. This information is displayed to an operator 60 at the network operations center 13. The process queue status requests process 55 functions to provide an analysis of the efficiency of the processes described in the broadcast files process 59, to improve parameters associated with the process queue process 58.
Thus, the ad-hoc file delivery system 20 and method 30 provides for a non- scheduled file delivery service that delivers files 52 to requested locations within a prescribed time period. Four exemplary periods are preferably employed, including two hours, four hours, eight hours, and twenty-four hours. In addition, a best effort service delivers the files 52 on a best-effort basis not to exceed seven days.
For the purposes of completeness, Fig. 5 is a flow diagram illustrating an exemplary embodiment of the ad-hoc file delivery method 30. The ad-hoc file delivery system 20 and method 30 is implemented such that a content provider 1 1 submits
(transmits 61 ) content comprising one or more files 52 to the network operations center 13 for delivery and requests delivery within one of the prescribed time periods. The one or more files 52 are submitted to the server 25 at the network operations center 13, and after complete receipt, the one or more files 52 are retrieved from the server 25 and placed into (stored 62 in) the priority-based service queue 33 for transmission. The priorities are assigned according the delivery time that is requested by the client. The broadcast server retrieves 63 the one or more files 52 from the service queue 33 and transmits 64 the one or more files 52 on one of a number of available broadcast channels to the one or more client personal computers 16.
A data dictionary is used in the ad-hoc delivery method 30 is given in the following table. The data dictionary is used to describe the algorithms of the processing queues 33, 36, 37.
Name Type Definition ftp data DS Temporary storage location for the content provider's data. It maintains the data in a predefined directory structure: { Scheduled-!- Ad- Hoc+On-demand } Thus, ad-hoc file delivery systems and methods for use with a one way data distribution system that distributes data files to personal computers have been disclosed. It is to be understood that the described embodiments are merely illustrative of some of the many specific embodiments that represent applications of the principles of the present invention. Clearly, numerous and other arrangements can be readily devised by those skilled in the art without departing from the scope of the invention.