Patent Publication Number: US-2021176226-A1

Title: System and method for providing a content delivery network via a motor vehicle

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 16/158,845 filed on Oct. 12, 2018, which is a continuation of U.S. patent application Ser. No. 14/993,396 (now U.S. Pat. No. 10,104,054), filed on Jan. 12, 2016, which is a continuation Ser. No. 14/574,011 (now U.S. Pat. No. 9,264,904), filed Dec. 17, 2014, which is a continuation of U.S. patent application Ser. No. 13/159,976 (now U.S. Pat. No. 8,937,903), filed Jun. 14, 2011, The contents of each of the foregoing is/are hereby incorporated by reference into this application as if set forth herein in full. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure generally relates to communications networks, and more particularly relates to content delivery networks. 
     BACKGROUND 
     Packet-switched networks, such as networks based on the TCP/IP protocol suite, can distribute a rich array of digital content to a variety of client applications. One popular application is a personal computer browser for retrieving documents over the Internet written in the Hypertext Markup Language (HTML). Frequently, these documents include embedded content. Where once the digital content consisted primarily of text and static images, digital content has grown to include audio and video content as well as dynamic content customized for an individual user. 
     It is often advantageous when distributing digital content across a packet-switched network to divide the duty of answering content requests among a plurality of geographically dispersed servers. For example, popular Web sites on the Internet often provide links to “mirror” sites that replicate original content at a number of geographically dispersed locations. A more recent alternative to mirroring is content distribution networks (CDNs) that dynamically redirect content requests to a cache server situated closer to the client issuing the request. CDNs either co-locate cache servers within Internet Service Providers or deploy them within their own separate networks. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       It will be appreciated that for simplicity and clarity of illustration, elements illustrated in the Figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements are exaggerated relative to other elements. Embodiments incorporating teachings of the present disclosure are shown and described with respect to the drawings presented herein, in which: 
         FIG. 1  is a block diagram illustrating a communications network in accordance with an embodiment of the present disclosure; 
         FIG. 2  is a block diagram illustrating a content distribution network that can be used in conjunction with the communications network of  FIG. 1 ; 
         FIGS. 3 and 4  are flow diagrams illustrating a method for providing a mobile cache server within a content distribution network; and 
         FIG. 5  is an illustrative embodiment of a general computer system. 
     
    
    
     The use of the same reference symbols in different drawings indicates similar or identical items. 
     DETAILED DESCRIPTION OF THE DRAWINGS 
     The numerous innovative teachings of the present application will be described with particular reference to the presently preferred exemplary embodiments. However, it should be understood that this class of embodiments provides only a few examples of the many advantageous uses of the innovative teachings herein. In general, statements made in the specification of the present application do not necessarily limit any of the various claimed inventions. Moreover, some statements may apply to some inventive features but not to others. 
       FIG. 1  shows a geographically dispersed network  100 , such as the Internet. Network  100  can include routers  102 ,  104 , and  106  that communicate with each other and form an autonomous system (AS)  108 . AS  108  can connect to other ASs that form network  100  through peering points at routers  102  and  104 . Additionally, AS  108  can include client systems  110 ,  112 ,  114 , and  116  connected to respective routers  102 ,  104 , and  106  to access the network  100 . Router  102  can provide ingress and egress for client system  110 . Similarly, router  104  can provide ingress and egress for client system  112 . Router  106  can provide ingress and egress for both of client systems  114  and  116 . 
     AS  108  can further include a Domain Name System (DNS) server  118 . DNS server  118  can translate a human readable hostname, such as www.att.com, into an Internet Protocol (IP) address. For example, client system  110  can send a request to resolve a hostname to DNS server  118 . DNS server  118  can provide client system  110  with an IP address corresponding to the hostname. DNS server  118  may provide the IP address from a cache of hostname-IP address pairs or may request the IP address corresponding to the hostname from an authoritative DNS server for the domain to which the hostname belongs. 
     Client systems  110 ,  112 ,  114 , and  116  can retrieve information from a server  120 . For example, client system  112  can retrieve a web page provided by server  120 . Additionally, client system  112  may download content files, such as graphics, audio, and video content, and program files such as software updates, from server  120 . The time required for client system  112  to retrieve the information from the server  120  normally is related to the size of the file, the distance the information travels, and congestion along the route. Additionally, the load on the server  120  is related to the number of client systems  110 ,  112 ,  114 , and  116  that are actively retrieving information from the server  120 . As such, the resources such as processor, memory, and bandwidth available to the server  120  limit the number of client systems  110 ,  112 ,  114 , and  116  that can simultaneously retrieve information from the server  120 . 
     Additionally, the network can include cache servers  122  and  124  that replicate content on the server  120  and that can be located more closely within the network to the client systems  110 ,  112 ,  114 , and  116 . Cache server  122  can link to router  102 , and cache server  124  can link to router  106 . Client systems  110 ,  112 ,  114 , and  116  can be assigned cache server  122  or  124  to decrease the time needed to retrieve information, such as by selecting the cache server closer to the particular client system. The network distance between a cache server and client system can be determined by network cost and access time. As such, the effective network distance between the cache server and the client system may be different from the geographic distance. 
     When assigning cache servers  122  and  124  to client systems  110 ,  112 ,  114 , and  116 , the cache server closest to the client can be selected. The closest cache server may be the cache server having a shortest network distance, a lowest network cost, a lowest network latency, a highest link capacity, a lowest load, or any combination thereof. Client system  110  can be assigned cache server  122 , and client systems  114  and  116  can be assigned to cache server  124 . The network costs of assigning client system  112  to either of cache server  122  or  124  may be substantially identical. When the network costs associated with the link between router  102  and router  104  are marginally lower than the network costs associated with the link between router  104  and router  106 , client  112  may be assigned to cache server  124 . 
     Client system  112  may send a request for information to cache server  124 . If cache server  124  has the information stored in a cache, it can provide the information to client system  112 . This can decrease the distance the information travels and reduce the time to retrieve the information. Alternatively, when cache server  124  does not have the information, it can retrieve the information from server  120  prior to providing the information to the client system  112 . In an embodiment, cache server  124  may attempt to retrieve the information from cache server  122  prior to retrieving the information from server  120 . The cache server  124  may retrieve the information from the server  120  only once, reducing the load on server  120  and network  100  such as, for example, when client system  114  requests the same information. 
     Cache server  124  can have a cache of a limited size. The addition of new content to the cache may require old content to be removed from the cache. The cache may utilize a least recently used (LRU) policy, a least frequently used (LFU) policy, or another cache policy known in the art. When the addition of relatively old or less popular content to the cache causes relatively hot or more popular content to be removed from the cache, an additional request for the relatively hot content can increase the time required to provide the relatively hot content to the client system, such as client system  114 . To maximize the cost and time savings of providing content from the cache, the most popular content may be stored in the cache, while less popular content is retrieved from server  120 . 
       FIG. 2  shows a content distribution network  200  that can be used in conjunction with communications network  100 . The content distribution network  200  includes a base station  202 , cache servers  204  and  206 , client devices  208 ,  210 ,  212 , and  214 , and the content server  120  of the AS  108 . The cache server  204  can be incorporated into a motor vehicle  216 , such that the cache server can be mounted within the motor vehicle. The cache server  204  can use an access point  218  built into the motor vehicle to create localized coverage areas  220  and  220   a , which can be micro cells within the content distribution network  200 . The cache server  206  can be incorporated into a motor vehicle  222 , such that the cache server can be mounted within the motor vehicle. The cache server  206  can use an access point  224  built into the motor vehicle to create localized coverage area  226 , which can be a micro cell within the content distribution network  200 . 
     The localized coverage areas  220  and  220   a  can be wireless networks created by the access point  218 , and the localized coverage area  226  can be created by the access point  224 . Depending on the wireless technology, a micro cell can be referred to as a femtocell, or as a hot spot in case of Wireless Fidelity (WiFi) or Bluetooth technologies. The base station  202  is in communication with the content server  120  of AS  108 , with the cache server  204 , and with the cache server  206 . The base station  202  is in communication with the cache servers  204  and  206  via cellular connections  228  of a cellular network  230 . The cache server  204  can communicate with the client devices  208  and  210  when the client devices are within the localized coverage area  220 . The cache server  204  can also communicate with the client devices  212  and  214  when the client devices are within the localized coverage area  220   a . The cache server  206  can communicate with the client device  214  when the client device is within the localized coverage area  226 . 
     The cache servers  204  and  206  can receive popular content from the content server  120  in the AS  108 , such as news websites, commonly accessed songs or videos, and the like. The popular content can be determined based on information obtained by the content server  120 , such as a number of times that specific content is requested. The content server  120  can push the popular content to the cache servers  204  and  206  via the cellular connection  228  of the cellular network  230  serviced by the base station  202 . The cellular connection  228  can be a cellular link between the cache server  204  and the content distribution network  200 . In an embodiment, the cache server  204  can receive the popular content at night, during periods of low loads on cellular link  228 , and the like. 
     As the motor vehicle  216  moves around the distribution network  200 , the hot spot created by the access point  218  can move from the localized coverage area  220  to the localized coverage area  220   a , and to any area along the path traveled by the motor vehicle. In an embodiment, the cache server  204  can activate the access point  218  to create the localized coverage area  220  when the motor vehicle is turned off, such that the localized coverage area is not provided while the motor vehicle  216  is moving through the content distribution network  200 . The localized area of coverage  220  or  220   a  can be a hot spot for a particular Internet and cellular telephone service provider. That is, the client devices  208 ,  210 ,  212 , and  214  associated with the particular Internet and cellular telephone service provider can detect the localized coverage area  220  or  220   a  as a hot spot or femtocell, and can connect to the access point  218  of the cache server  204 . The localized coverage area  220  can encompass an outdoor coverage area or an indoor coverage area near the motor vehicle  216 , such as a parking lot, park, library, hospital, retail store, residence, and the like. For example, if the motor vehicle has stopped and has been turned off next to a park, the localized coverage area  220  may extend into the park. The size of the localized coverage areas  220  and  220   a  can be determined at least in part by a transmission power of the access point  218 , as well as path loss, shadowing, and the like on a wireless signal from the access point. 
     In an embodiment, the localized coverage area  220   a  of the cache server  204  can overlap with the localized coverage area  226  of the cache server  206 , such that the cache servers can detect each other. The cache servers  204  and  206  can then pass authentication information to each other so that the cache servers can mutually authenticate that each of the cache servers are associated with the same service provider. The cache server  204  can determine whether the cache server  206  has new content, which can be updates to content currently cached in the cache server  204 , content that is different than the content currently cached in the cache server  204 , and the like. When the cache server  204  determines that the cache server  206  has new content, the cache server  204  can utilize the new content to increase the amount of content available in the localized coverage areas  220  and  220   a.    
     For example, the cache server  204  can provide the client devices  208 - 214  with access to the new content. The cache server  204  may receive the new content from the cache server  206 , and cache the new content in a memory of the cache server  204 . Alternatively, the cache server  204  may create a look up table associating an IP address for the cache server  206  with the new content. Thus, the cache server  204  can then either have a copy of the new content to provide to the client devices  208 - 214 , or have the location of the new content stored in the look up table. 
     The client devices  208 - 214  can be multimode devices, such that the client devices can communicate with both the base station  202  via the cellular connection  228 , and with the access point  218  via a Bluetooth or WiFi signal. When the client device  208  enters the localized coverage area  220 , the client device can attempt to connect to the access point  218  via transmission and reception of attachment signaling. In an embodiment, a connecting signaling from a client device can include a Location Area Update (LAU) and/or Routing Area Update (RAU), or any other synchronization procedure compatible with the wireless technology of the localized coverage area  220 , such as WiFi, Worldwide Interoperability for Microwave Access (WiMAX), Enhanced General Packet Radio Service (Enhanced GPRS), Long Term Evolution (LTE), Ultra Mobile Broadband (UMB), Zigbee, or the like. 
     The client device  208  can also provide authentication information to cache server  204 . The authentication information can include universal subscriber identification module ((U)SIM) based credentials or the like for the client device  208 . The cache server  204  can then utilize the cellular connection  228  and the base station  202  to send the authentication information to an authentication server  232 , which can remotely verify credentials of the client device  208 . In another embodiment, the cache server  204  can receive and store a list of authentication information including the authentication information for each client device associated with the particular Internet and cellular telephone provider from the authentication server  232 . The cache server  204  can then compare the authentication information provided by the client device  218  with the authentication information of the list of authentication information stored within the cache server to verify that the client device can connect to the access point  218 . 
     When the client device has been authenticated and connected to the access point  218 , the cache server  204  can receive a content request from the client device. If the content request is associated with the popular content cached in the cache server  204 , the content can be provided to the client device. Additionally, the cache server  204  can verify that the requested content has not been updated since the content was cached in the cache server before the cache server provides the requested content to the client device  208 . If the content has been updated, the cache server  204  can connect to the AS  108  via the cellular connection  228  and the base station  202  to retrieve the most recent content. If the cache server  204  has not cached the requested content, the cache server can connect to a content server, such as content server  120 , that has the content via the cellular connection  228 , and can receive the requested content. Alternatively, if the cache server  204  has not cached the requested content, the cache server can utilize the look up table and return an IP address of a cache server, such as cache server  206 , that does have the requested content to the client device  208 . The cache server  204  can provide the client device  210  with popular content in a similar fashion as discussed for client device  208 . 
     In an embodiment, if the client device  208  is in the process of downloading content from the cache server  204  and the motor vehicle  216  drives away, the client device can then connect to the base station  202  via the cellular connection  228  of the cellular network  230  to receive the remainder of the content. In another embodiment, the client device  214  may be utilizing the cellular connection  228  of the cellular network  230  to download content when the motor vehicle  216  with the cache server  204  stops near the client device  214 . The motor vehicle  216  can then be turned off, and the cache server  204  can activate the access point  218  to create the localized coverage area  220   a . If the client device  214  is located within the localized coverage area  220   a , the client device can detect the coverage area as a hot spot. The client device  214  can then connect with the access point  218 , and can switch from the cellular network  230  to the localized coverage area  220   a  to download the remainder of the content. Thus, the client devices  208 - 214  can utilize the localized coverage areas  220  and  220   a  created by the access point  218  of the cache server  204  to download content instead of utilizing the cellular connection  228  of the cellular network  230 . 
       FIGS. 3 and 4  illustrate a method  300  for providing a mobile cache server within a content distribution network. At block  302 , popular content is received by the cache server from the content distribution network when a load of a cellular link to the content distribution network is low. The cache server can be located within a motor vehicle. In an embodiment, the motor vehicle can be a rental car, a service vehicle of an Internet and cellular telephone service provider, or the like. The popular content can include news websites, commonly accessed songs, and commonly accessed videos. The popular content can be received via a cellular data connection, such as the cellular link, of a cellular network. At block  304 , the popular content is cached in the cache server. A determination is made that the motor vehicle is turned off at block  306 . At block  308 , a wireless signal is broadcast as part of a wireless network when the motor vehicle is turned off. The wireless network can be a localized coverage area, such as a femtocell, a hot spot, or the like, from an access point of the cache server. At block  310 , a determination is made whether a second cache server is detected. If the second cache server is not detected, the flow continues below at block  316 . 
     Now referring to  FIG. 4 , if the second cache server is detected, the cache server and the second cache server mutually authenticate each other at block  310 . The cache server can authenticate each other by passing authentication information to each other, and verifying the authentication information via an authentication server or with authentication information stored in the cache servers. At block  312 , a determination is made that the second cache server has new content. The new content can be updates to content already stored on the cache server, content that is not currently stored in the cache server, and the like. The new content is received from the second cache server at block  314 . In another embodiment, the cache server can create a lookup table to identify that the new content is located in the second cache server without receiving and storing the new content in the cache server. 
     Referring back to  FIG. 3 , a request to join the wireless network is received from a device at block  316 . The device can be a smart cellular telephone, a portable computer, a tablet computer, a personal digital assistant, or the like. Authentication information is received from the device at block  318 . At block  320 , a determination is made whether a list of authentication information is received at the cache server. An authentication file including a list of authentication information for each of a plurality of devices can be received when the load on the cellular link to the content distribution network is low. If the list of authentication information is received at the cache server, the authentication information of the device is compared to the list of authentication information at block  322 . At block  324 , a determination is made that the authentication information of the device is valid when the authentication information of the device matches the list of authentication information. 
     However, if the list of authentication information is not received in the cache server, the authentication information is transmitted to an authentication server within the content distribution network via the cellular data connection or link of the cellular network at block  326 . At block  328 , a notification signal indicating a verification of the authentication information is received at the cache server via the cellular data connection or link of the cellular network. At block  330 , the device is authenticated at the cache server. Access to the popular content cached in the cache server is provided via the wireless network after the device is authenticated at block  332 . 
       FIG. 5  shows an illustrative embodiment of a general computer system  500 . The computer system  500  can include a set of instructions that can be executed to cause the computer system to perform any one or more of the methods or computer based functions disclosed herein. The computer system  500  may operate as a standalone device or may be connected, such as by using a network, to other computer systems or peripheral devices. 
     In a networked deployment, the computer system may operate in the capacity of a server or as a client user computer in a server-client user network environment, or as a peer computer system in a peer-to-peer (or distributed) network environment. The computer system  500  can also be implemented as or incorporated into various devices, such as a personal computer (PC), a tablet PC, an STB, a personal digital assistant (PDA), a mobile device, a palmtop computer, a laptop computer, a desktop computer, a communications device, a wireless telephone, a land-line telephone, a control system, a camera, a scanner, a facsimile machine, a printer, a pager, a personal trusted device, a web appliance, a network router, switch or bridge, or any other machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. In a particular embodiment, the computer system  500  can be implemented using electronic devices that provide voice, video or data communication. Further, while a single computer system  500  is illustrated, the term “system” shall also be taken to include any collection of systems or sub-systems that individually or jointly execute a set, or multiple sets, of instructions to perform one or more computer functions. 
     The computer system  500  may include a processor  502 , such as a central processing unit (CPU), a graphics processing unit (GPU), or both. Moreover, the computer system  500  can include a main memory  504  and a static memory  506  that can communicate with each other via a bus  508 . As shown, the computer system  500  may further include a video display unit  510  such as a liquid crystal display (LCD), an organic light emitting diode (OLED), a flat panel display, a solid state display, or a cathode ray tube (CRT). Additionally, the computer system  500  may include an input device  512  such as a keyboard, and a cursor control device  514  such as a mouse. The computer system  500  can also include a disk drive unit  516 , a signal generation device  518  such as a speaker or remote control, and a network interface device  520  to communicate with a network  526 . In a particular embodiment, the disk drive unit  516  may include a computer-readable medium  522  in which one or more sets of instructions  524 , such as software, can be embedded. The computer-readable medium can be a non-transitory computer readable medium, such as a hard disk drive, a flash memory, a read-only memory, a compact disk, a digital versatile disk, a cache, a random-access memory, and the like. Further, the instructions  524  may embody one or more of the methods or logic as described herein. In a particular embodiment, the instructions  524  may reside completely, or at least partially, within the main memory  504 , the static memory  506 , and/or within the processor  502  during execution by the computer system  500 . The main memory  504  and the processor  502  also may include computer-readable media. 
     The illustrations of the embodiments described herein are intended to provide a general understanding of the structure of the various embodiments. The illustrations are not intended to serve as a complete description of all of the elements and features of apparatus and systems that utilize the structures or methods described herein. Many other embodiments may be apparent to those of skill in the art upon reviewing the disclosure. Other embodiments may be utilized and derived from the disclosure, such that structural and logical substitutions and changes may be made without departing from the scope of the disclosure. Additionally, the illustrations are merely representational and may not be drawn to scale. Certain proportions within the illustrations may be exaggerated, while other proportions may be minimized. Accordingly, the disclosure and the FIGs. are to be regarded as illustrative rather than restrictive. 
     The Abstract of the Disclosure is provided to comply with 37 C.F.R. § 1.72(b) and is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description of the Drawings, various features may be grouped together or described in a single embodiment for the purpose of streamlining the disclosure. This disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may be directed to less than all of the features of any of the disclosed embodiments. Thus, the following claims are incorporated into the Detailed Description of the Drawings, with each claim standing on its own as defining separately claimed subject matter. 
     The above disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover all such modifications, enhancements, and other embodiments which fall within the true spirit and scope of the present disclosed subject matter. Thus, to the maximum extent allowed by law, the scope of the present disclosed subject matter is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.