Abstract:
Striped Multiplexing Download Queue software facilitates and increases throughput for client-server downloads through a limited communication device. In the “DS Download Station” application, this is used to queue many requests and to broadcast download segments to requesters seeking the same data. This works by employing a “download stripe” on both the server and client. The download stripe on the server side tracks acknowledgements from clients per download segment. On the client side, the stripe tracks received segments to account for duplicate data. Requesters are queued on a first-come first-serve basis. Requesters in the queue may receive segments of downloads while waiting in queue, if the client at the front of the queue is downloading the same file. This recursively saves waiting time for clients in the queue.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims the benefit of Provisional Application No. 60/774,195, filed Feb. 17, 2006, the entire content of which is hereby incorporated by reference in this application. 
    
    
     FIELD 
     The exemplary illustrative non-limiting implementations relate to systems and/or methods for distributing data to client devices. More particularly, the exemplary illustrative non-limiting implementations relate to systems and/or methods for distributing a game and/or other data to a plurality of client game devices for game play, or the like. 
     BACKGROUND AND SUMMARY 
     With the current availability of networking technology, many video games have been designed to allow a number of players to participate in a game from different locations using different machines. Players often will purchase a game, pay to use an online account, connect to a network using a network cable, and compete against other players in a network environment. 
     Unfortunately, this conventional model has several drawbacks. First, it often is difficult for a group of players to share a common environment and each play their own version of a game competitively against one another. For example, it often is difficult for a group of players to meet in someone&#39;s living room and each play their own version of the game against one another. Each machine would need to be provided with its own display, and each player would need a network connection. Alternatively, the players could play on one television using one game machine, but there are limitations on the number of players that can play the game. These conventional limitations occur because the display typically must to be split to show each individual perspective. Additionally, if a single display is used, each player can see the other players&#39; respective viewpoints, thus becoming aware of where those players are going and what those players are doing. 
     Recently, smaller handheld devices have been provided with wireless networking capabilities, solving the need for each player to have his own display. These devices may allow players to play a game over a local area network, and friends can gather and compete with one another. In the absence of a server, however, one or more of the wireless devices must act as a server, taking on the role of serving required game play information to all of the devices participating in the game. This distribution requirement can burden the devices, which often are designed to play games, rather than to serve requests from other devices. 
     Even if a server was provided, it often would be handling a plurality of simultaneous download requests from the devices. While a more expensive server might be able to quickly handle these requests more quickly, it nonetheless is desirable to provide an effective solution to this problem where a limited capability server can efficiently handle a plurality of requests without the need for high-priced hardware. 
     Another possible use of a server would be to provide that server with a plurality of game demonstrations. The server then could be used to respond to a number of game demonstration file requests. However, this arrangement may have the drawback of creating a bottleneck at the server when a large number of file requests are received in a relatively short period of time. 
     Problems may occur with conventional arrangements because a server typically will receive a number of requests for a game file and process the requests in the order received. This one-at-a-time processing makes the slowdown worse, because all other users must wait while all the requests ahead of them are served. Typically, the requests come at different times, and the server begins processing one request for a file as it is receiving other requests. Any machine later requesting the file has to wait in line until the preceding file requests have been processed by the server. 
     Thus, it will be appreciated that there is a need in the art to overcome one or more of the above-noted problems. According to one aspect of the exemplary illustrative non-limiting implementations, a download station and/or server is provided whereby a plurality of file requests can be received and processed in an efficient and effective manner. If a plurality of devices are requesting a single file, the server can send packets, or pieces of the file, to each device simultaneously. The devices can then combine these pieces to create the desired file. 
     Through this method, the server does not have to wait until it is completed processing a single file request before sending the file to a second device. If a device requests a file, the server will begin transmission. If a second device then requests the same file at a later time, the server will continue transmission of the file, and the second device can also receive the same transmission. The later requesting device will receive the packets relating to the presently untransmitted portions of the file, and then can have the previously transmitted portions of the file sent to it when the previous send request is completed. Thus, at the point where the second device moves up to first in a request queue, it has already received a portion of the file, and completing the file request takes a shorter period of time. Additionally, if a third device has then requested the file, the packets sent to complete the file on the second device can also be sent to the third device, and when that device has moved to the front of the request queue, it will then also have a partially completed version of the file in memory. 
     This method allows a server to process a plurality of requests for a similar file much more quickly than if the server had to send a full copy of the file to each device before it moved on to process the next file request. For example, if five users requested a file, each request coming at a different time, then the four later requesting users would receive all of the packets currently being sent to the first requesting user while the four users were waiting in the queue. Then, when the first user&#39;s request was complete, the three remaining later requesting users would also receive the “fill in” packets sent to the second requesting user&#39;s device. This method continues until the last user is the first in line, at which point that user&#39;s device already has a portion of the file stored therein, allowing completion of the file in a much shorter time. If additional users have subsequently requested the file, they also will receive pieces of the file sent to any users ahead of them in the queue, so the process can continue, potentially perpetually, eliminating the bottleneck associated with multiple file requests. 
     According to another aspect of the exemplary illustrative non-limiting implementations, a server is provided with a method of tracking file-receipt acknowledgements. This allows the server to know which packets a given device has received. Once the device has moved to the head of the queue, the server can then determine which packets that device needs to complete the file. This prevents the server from having to re-send the entire file each time and relying on the device to fill in the appropriate packets. 
     According to a further aspect of the exemplary illustrative non-limiting implementations, a client device is provided with a method of tracking received packets. This way, if a device is, for example, fifth in the queue, the device does not redundantly store duplicate information which may be broadcast to it as it moves up in the queue. Because the server is specifically sending out packets based on the needs of the first device in the queue, a device which is fifth will not have its individual packet needs addressed until it is first in the queue. Because more than one device ahead of it may need the same packets from the server, the server would send those packets out based on the needs of the devices ahead of the fifth device as the queue advanced. By tracking the received packets, the device does not attempt to store duplicate versions of the information as it is broadcasted out based on the needs of the preceding devices. 
     According to another aspect of the exemplary illustrative non-limiting implementations, packets are sent to a plurality of devices simultaneously. Each device will put in its request for a file, and then monitor a broadcast channel for packets pertaining to that file. Whenever a packet is detected, the device checks an internal list of received packets, and if the presently sent packet has not been received and stored, the device stores the packet and flags it as received. 
     One application for the exemplary illustrative non-limiting embodiments is use in a game demonstration distribution server. A store or other location provided with a plurality of operable game devices can run a server distributing demo versions of games to various devices. This application prevents a user from having to change a cartridge to demo a new game. Accordingly, the server will be able to provide multiple users with new games more quickly, encouraging users to demo and possibly buy multiple games. 
     While the application of the exemplary illustrative non-limiting embodiments has been discussed in terms of game systems, it will be appreciated that this method could be used in any distribution system where files are distributed from a central server to a plurality of requesting devices. 
     Certain exemplary illustrative embodiments relate to a method of distributing files from a server to a plurality of client devices in operable communication with the server. The method may comprise, for example, maintaining a queue of requests, with each request being associated with a client device and a client request for a file. One or more needed portions of the file associated with the request first in queue may be identified, with the one or more needed portions of the file corresponding to portions of the file that the client device associated with the request has not yet received. The needed portions of the file may be simultaneously sent for receipt by the client device associated with the request first in queue and for receipt by each client device also having requested the file. 
     Certain other exemplary illustrative embodiments relate to a system for distributing files. Such systems may comprise a server and a plurality of client devices. The server and the client devices may be in operable communication. Such systems may further comprise a database of files operably connected to the server. The server may be operable to maintain a queue of requests, each request being associated with a client device and a client request for a file; identify one or more needed portions of the file associated with the request first in queue, the one or more needed portions of the file corresponding to portions of the file that the client device associated with the request has not yet received; and simultaneously send the needed portions of the file for receipt by the client device associated with the request first in queue and for receipt by each client device also having requested the file. Each client device may be operable to receive the file portions sent to it by the server. 
     Yet further exemplary illustrative embodiments relate to a download station comprising a storage location storing a plurality of files for download to client devices and a processor. The processor may be operable to execute the following steps of: receiving requests for files from the client devices; enqueuing the requests in a queue; tracking the files the client devices have requested, portions of the files already downloaded by the client devices, and portions of the files yet to be downloaded by the client devices; and, simultaneously broadcasting at least a portion of the file for receipt by the client devices based in part on the files the client devices have requested, the portions of the files already downloaded by the client devices, and the portions of the files yet to be downloaded by the client devices. 
     In certain non-limiting implementations, the portions of the file are sent wirelessly, and in certain non-limiting implementations the portions of the file are sent via a single channel. The client devices may be portable game devices, and the files may be games executable by the client devices and/or game-related data interpretable by the client device. The portions of the files may be packets. A completed request may be dequeued based on a checksum of the file associated with the request. A server stripe may be maintained on the server. The server stripe may identify, for each request, downloaded portions of the file associated with the request and not yet downloaded portions of the file associated with the request. A request may be dequeued based on the server stripe. The client devices to which the file will be sent may be determined based at least in part on the server stripe. A client stripe on the client device may be maintained. The client stripe may include portions of the file already received by the client device. Portions of the file may be filtered based on the client stripe, the filtering being performed by the client device. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features and advantages will be better and more completely understood by reference to the following detailed description of exemplary illustrative embodiments in conjunction with the drawings, of which: 
         FIG. 1  shows an exemplary external view of an illustrative game device; 
         FIG. 2  shows a diagram illustrating an exemplary internal configuration of an illustrative game device; 
         FIG. 3  shows a representation of an exemplary game server and a plurality of illustrative devices communicating with the server; 
         FIG. 4  shows a representation of an exemplary client request queuing operation; 
         FIG. 5  shows a representation of an exemplary client request processing operation performed by a server; 
         FIG. 6  shows a representation of an exemplary server information receipt processing operation performed by a client; 
         FIG. 7A  shows an illustrative flowchart detailing an exemplary client request queuing operation; 
         FIG. 7B  shows an illustrative flowchart detailing an exemplary queue processing operation; 
         FIG. 8  shows an illustrative flowchart detailing an exemplary client request processing operation; and, 
         FIG. 9  shows an illustrative flowchart detailing an exemplary server information receipt processing operation. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now more particularly to the drawings,  FIG. 1  is an external view of a game device included in the wireless network system shown in  FIG. 3 . In  FIG. 1 , a game device includes a first liquid crystal display (LCD)  11  and a second LCD  12 . A housing  13  comprises an upper housing  13   a  and a lower housing  13   b . The first LCD  11  is disposed in the upper housing  13   a , and the second LCD  12  is disposed in the lower housing  13   b . Each of the first and second LCDs  11  and  12  has a resolution of 256 dots×192 dots. Although the present illustrative game device shows an example where LCDs are used as display devices, any other display devices, such as display devices using, for example, electroluminescence (EL) technology, can be used. Also, display devices of any level of resolution can be used. 
     The upper housing  13   a  has formed therein sound holes  18   a  and  18   b  for emitting sound from a pair of loudspeakers ( 30   a  and  30   b  in  FIG. 2 , which will be described below). The lower housing  13   b  is provided with input mechanisms, such as, for example, a cross switch  14   a , a start switch  14   b , a select switch  14   c , an “A” button  14   d , a “B” button  14   e , an “X” button  14   f , a “Y” button  14   g , an “L” button  14 L, and an “R” button  14 R. Also, a further input mechanism (touch panel  15 ) is mounted on the screen of the second LCD  12 . The lower housing  13   b  is provided with a power switch  19  and insertion slots for receiving a memory card  17  and a stylus  16 . The stylus  16  is used for input operations on the touch panel  15 . 
     The memory card  17  is a storage medium having stored therein a game program and a wireless communication program. The memory card is removably loaded into an insertion slot provided in the lower housing  13   b.    
     The internal configuration of the game device  10  will be described with reference to  FIG. 2 . In  FIG. 2 , a CPU core  21  is mounted on an electronic circuit board  20 , which is disposed in the housing  13 . Via a bus  22 , the CPU core  21  is connected to a connector  23 , an input/output interface circuit  25  (labeled “I/F CIRCUIT” in  FIG. 2 ), a first graphics processing unit (GPU)  26 , a second GPU  27 , a RAM  24 , an LCD controller  31 , and a wireless communication section  33 . The memory card  17  is detachably connected to the connector  23 . The memory card  17  includes a ROM  17   a , which has stored therein a game program and a wireless communication program, and a RAM  17   b , which has retrievably stored backup data stored therein. The game program and the wireless communication program, which are stored in the ROM  17   a  of the memory card  17 , are loaded on to the RAM  24 , and executed by the CPU core  21 . In addition to the game program and the wireless communication program, the RAM  24  stores temporary data, which is obtained by the CPU core  22  for executing the game program, and data for generating a game image. The I/F circuit  25  is operably connected to the touch panel  15 , a right loudspeaker  30   a , a left loudspeaker  30   b , and an operation switch section  14  (shown in  FIG. 1 , including the cross switch  14   a , the “A” button  14   d , etc). The right loudspeaker  30   a  and the left loudspeaker  30   b  are placed inside the sound holes  18   a  and  18   b.    
     Although the example illustrates an example where the game device  10  includes only one CPU core, the device is not so limited. For example, the game device may be provided with a plurality of CPU cores which share processes by the CPU core  21 . 
     The first GPU  26  is connected to a first video-RAM (VRAM)  28 . The second GPU  27  is connected to a second VRAM  29 . In accordance with an instruction from the CPU core  21 , the first GPU  26  generates a first game image on the basis of data used for image generation stored in the RAM  24 , and writes the image into the first VRAM  28 . Similarly, in accordance with an instruction from the CPU core  21 , the second GPU  27  generates a second game image, and writes the image into the second VRAM  29 . The first and second VRAMs  28  and  29  are connected to the LCD controller  31 . 
     The LCD controller  31  includes a register  32 . The register  32  stores a value of 0 or 1 in accordance with an instruction from the CPU core  21 . If the value in the register  32  is 0, the LCD controller  31  outputs to the first LCD  11  the first game image written on the first VRAM  28 , and also outputs to the second LCD  12  the second game image written on the second VRAM  29 . Alternatively, if the value of the register  32  is 1, the first game image written on the first VRAM  28  is output to the second LCD  12 , and the second game image written on the second VRAM  29  is output to the first LCD  11 . 
     The wireless communication section  33  is operable to exchange game process and other data with a wireless communication section  33  of another game device. In the present example device, it is assumed that a wireless communication section has a radio communication function in conformity with IEEE 802.11 wireless LAN standards, for example. 
     It will be appreciated that the above-described configuration of the game device  10  is merely illustrative and should not be construed as limiting. Also, the game program and wireless communication program may be supplied to the game device  10  not only via an external storage medium, such as the memory card  17 , but also via a wired or wireless communication channel. Alternatively or in addition, the game program and wireless communication program may be previously stored in a nonvolatile storage device within the game device  10 . 
     According to one aspect of the exemplary illustrative non-limiting implementations, as shown in  FIG. 3 , a server  291  is provided to serve out copies of files to one or more requesting devices  295 . The server  291  is configured to communicate wirelessly  293  with the devices  295 , and the devices  295  are also provided with wireless communication  297  capability. 
     According to an exemplary illustrative non-limiting embodiment, the server  291  receives requests from the devices and broadcasts packets pertaining to requested files. Devices that request a particular file monitor the broadcast channel and receive and store the broadcast packets, assembling them to complete the requested file. 
     An exemplary representation of a server queuing operation is shown in  FIG. 4 . As time passes, requests  301  are received from various clients. The server builds a client requests queue  303 , which is implemented as a first-in, first-out (FIFO) queue in this exemplary representation. If the request  305  from Client  1  is received first, it will be the first request processed. Although this exemplary representation shows a FIFO queue, any type of queue may be used instead of a FIFO queue, such as, for example, a LIFO queue, a priority queue, etc. Also, it will be appreciated that the queue may be implemented as a one or more stacks, as a heap, etc. In the example shown in  FIG. 4 , Clients  1  and  3  request File A, and Client  2  requests File B, all for download. 
       FIG. 5  shows an exemplary representation of a client request processing operation performed by a server. In this representation, a client first in the queue  303  has requested file A  305 . A client second in the queue has requested file B, and a client third in the queue also has requested file A. 
     In a conventional system, the server would process the requests in a designated order. For example, if a FIFO queue were implemented with such a conventional system, each client would receive their file in the order that they requested it. This means that the client also requesting file A and third in line would have to wait for A to be sent to the first client, for B to be sent to the second client, and then for A to be re-sent to the third client. 
     According to one aspect of the exemplary illustrative non-limiting implementations, once the first request for A  305  is being processed, the client third in line also can benefit from the processing of this request. Once the first request for A  305  is in, the server checks to see what information that client already has received. In this case, the information already received is designated by the “already sent” area  309 . Then, the server sends all information that had not yet been received by that client, designated by the “downloading file A” area  311 . However, because the server is broadcasting this information and the third client is monitoring the channel for information relating to file A, the third client also can store this information, partially completing the file requested by the third client. Once the server request for A is complete for the first client, the server then will move on and send file B  313 . Finally, after B is sent, the third client only needs to fill in the missing information designated by the “make up” area  315 . Because “make up” area  315  represents only a portion of the file, the client will not need to wait for the entire file to be re-sent in its entirety. Additionally, any other clients having subsequently requested file A will be able to receive the data that is being sent to the third client. This information corresponding to, for example, which clients have requested which files, the pieces of the files already received, and the pieces of the files yet to be received, is tracked in server stripe  307 , which may be located on the server. It will be appreciated that in certain other exemplary illustrative embodiments, other information in addition to and/or in place of the information described herein may be stored. Also, it will be appreciated that the server stripe (or corresponding information store) may be located on the client, in a separate database, etc., depending on the particular implementation. 
       FIG. 6  shows an exemplary representation of a server information receipt processing operation performed by a client. Because the requested files may be broadcasted to the client in a fragmented form, the client may need to track which packets have already been received. This tracking process allows the client to store the needed packets only once, and prevents a mistaken alteration of a checksum that may be used to check for file completeness. The client tracks the whole file  317 , and it can determine which packets have been received  319  and which packets are still needed  321 . If a packet is received that previously has not yet been received, the client saves the packet and updates the checksum and the marker for that packet. Once the checksum matches the expected sum, the client can stop downloading the file and can process it. It will be appreciated that in certain exemplary illustrative embodiments, the downloaded packets may be inserted into the ultimate file in the correct places, thus potentially eliminating the need to reorder the packet after all data has been received. It also will be appreciated that other data verification methods may be used apart from, or in addition to, checksums, such as wireless checksums. 
       FIG. 7A  shows a flowchart detailing an exemplary client request queuing operation. When the server receives a request from a client, the server needs to order those requests in some fashion. According to an exemplary representation, the server checks for incoming client requests  323 . If a request is received  325  the server adds the client request to the queue  327 . If no requests are received, or after the server has added the request to the queue, the server returns to looking for client requests  323 . 
       FIG. 7B  shows a flowchart detailing an exemplary queue processing operation. First, the server checks to see if there are any requests pending in the queue  329 . If the server finds a pending request  331 , the server processes that request and sends out the desired information. If the server does not find a request, or when the current request processing is complete, the server then checks the queue again for requests  329 . 
       FIG. 8  shows a flowchart detailing an exemplary client request processing operation. If the server finds a request pending in the queue, the server must then process that request. According to one aspect of an exemplary illustrative non-limiting implementation, the server checks markers which it has stored for a particular client. These markers may be set when earlier packets were broadcast while the current request was still pending in the queue. For example, if a file has ten packets, and packets two, three and seven have been sent while the current client was waiting in the queue, then markers corresponding to that client are set for those parts because the server has gotten a confirmation that the packets were received. Thus, the server knows which packets the client has not received and can send them out. In certain exemplary illustrative embodiments, alternatively, or in addition, the markers may be stored on the client side device. 
     Upon processing the client request, the server determines whether or not packets are still needed by this client  337 . If the file is complete, then the server can exit  339  processing for this particular request. If the client still needs packets, the server can send out a needed packet  341  and update the corresponding client marker  343 . The server must also check the queue to see if other clients were requesting the same file  349 . For example, if there were ten other clients requesting the same file, then the server would update the markers corresponding to those clients  351  so that when any of those clients reached the front of the queue, the server would not waste time re-sending a packet that that client had already received. The server then checks the packet markers for the current file  335  to determine again if any packets are additionally needed  337 . 
       FIG. 9  shows a flowchart detailing an exemplary server information receipt processing operation. According to one aspect of the illustrative exemplary non-limiting implementations, a client may use a checksum to verify that a file has been fully received. If the client updates this checksum based on the packets received, then it would be best if the client does not redundantly store a packet and mistakenly alter the checksum based on this redundant store. To that end, the client may be provided with a method to protect against redundant packet storage, an exemplary flow of which is shown in  FIG. 9 . 
     The client, which knows it is waiting for a request, checks for incoming data  353 . If incoming data is detected  355 , the client checks an internal set of data markers  357 . These markers are similar to the markers kept by the server and aid the client in determining which pieces of information still need to be stored. If the client determines that a particular packet is already present, the client does not store the packet and update the checksum. Using the example from above, the client would have markers two, three, and seven set, indicating that if packets two, three, or seven were detected, the client would not store that data again. If a particular packet does not need to be stored by a particular client, the client then goes back to checking for new incoming packets. 
     If the client does not yet have a detected packet, the client will store a copy of that packet  361  and adjust the checksum accordingly. The client then checks the checksum  363  to determine if the file is complete  365 . If the checksum matches the expected sum, then the file is complete and the client no longer needs to look for the file. If the file is not complete, then the client can update the corresponding data maker and continue to look for additional incoming packets. The client may also notify the server  371  that the piece of information was received. 
     While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.