Abstract:
Methods and apparatus for obtaining web content are disclosed. The method includes identifying resources identified by domain name references that a user may request, obtaining a status of at least one operating condition that affects operations of the communication device, fetching, in advance of the user requesting the content, network addresses of the resources so as to resolve the domain name references, and adapting a level of the fetching based upon the at least one operating condition. The network addresses of the resources are cached so as to generate cached network addresses, and if the user requests the content, the cached network addresses are utilized to access the resources associated with the content.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to communication devices. In particular, but not by way of limitation, the present invention relates to communications between a communication device and a network to obtain web content. 
       BACKGROUND OF THE INVENTION 
       [0002]    The Internet is a global system of interconnected computer networks that use an Internet Protocol to serve billions of users worldwide. It is a network of networks that consists of millions of private, public, academic, business, and government networks, of local to global scope, that are linked by a broad array of electronic, wireless and optical networking technologies. 
         [0003]    An Internet Protocol address (IP address) is a numerical label assigned to each device (e.g., computer, smartphone, server, printer) participating in a computer network that uses the Internet Protocol for communication. An IP address serves two principal functions: host (or network interface) identification and location addressing. 
         [0004]    IP addresses, however, are numeric addresses that are not easy for people to use and remember. As a consequence, a Domain Name System (DNS) was developed to translate human-friendly computer hostnames into IP addresses. Users take advantage of this when they recite meaningful Uniform Resource Locators (URLs) and e-mail addresses without having to know how the computer actually locates them. 
         [0005]    In addition, the DNS system makes it possible to assign domain names to groups of Internet resources and users in a meaningful way, independent of each entity&#39;s physical location. Because of this, World Wide Web (WWW) hyperlinks and Internet contact information can remain consistent and constant even if the current Internet routing arrangements change or the participant uses a mobile device. The Domain Name System also stores other types of information, such as the list of mail servers that accept email for a given Internet domain. By providing a worldwide, distributed keyword-based redirection service, the Domain Name System is an essential component of the functionality of the Internet. 
         [0006]    The Domain Name System distributes the responsibility of assigning domain names and mapping those names to IP addresses by designating authoritative name servers for each domain. Authoritative name servers are assigned to be responsible for their particular domains, and in turn can assign other authoritative name servers for their sub-domains. 
         [0007]    When users request content via the Internet with the user-friendly URLs, a DNS query is initiated that sends a request to a name server, and the name server returns IP addresses for the content associated with the domain. This process of translating domain names to IP addresses (also referred to as DNS resolution), however, may be a significant fraction of the time it takes to download a webpage. As a consequence, techniques have been developed to prefetch IP addresses for content before a user actually requests the content. In this way, when the user requests the content, the DNS resolution has already been performed. 
         [0008]    Performing DNS prefetching, however, may adversely affect performance of the device that is accessing the content. For example, known DNS prefetching operations utilize a substantial amount of power that may especially affect the use of mobile devices. In addition, DNS prefetching may actually delay the transmissions of other traffic that is needed to render a webpage; thus degrading webpage download time. As a consequence, existing DNS prefetching techniques are often unsatisfactory and are potentially counterproductive. 
       SUMMARY OF THE INVENTION 
       [0009]    Illustrative embodiments of the present invention that are shown in the drawings are summarized below. These and other embodiments are more fully described in the Detailed Description section. It is to be understood, however, that there is no intention to limit the invention to the forms described in this Summary of the Invention or in the Detailed Description. One skilled in the art can recognize that there are numerous modifications, equivalents, and alternative constructions that fall within the spirit and scope of the invention as expressed in the claims. 
         [0010]    In accordance with several embodiments, the invention may be characterized as a method for obtaining web content on a communication device. The method in this embodiment includes identifying resources associated with content that a user may request, and obtaining a status of at least one operating condition that affects operations of the communication device. In addition, in advance of the user requesting the content, network addresses of the resources are fetched so as to resolve the domain name references, and a level of the prefetching is adapted based upon the at least one operating condition. The network addresses of the resources are cached, and if the user requests the content, the cached network addresses are used to access the resources associated with the content. 
         [0011]    Other embodiments may be characterized as a mobile device that includes an application that enables a user to request web content that includes resources residing on at least one remote server. In addition, the mobile device includes a domain name system (DNS) prefetch manager that requests, before the user requests the web content, network addresses of the resources that are identified by domain name references. A transmitter is configured to transmit the requests for the network addresses to a remote server that initiates a translation of the domain name references to the network addresses, and a receiver to receive the network addresses via a reverse communication link. In addition, an adaptive DNS module is configured to receive information about at least one operating condition that affects operations of the mobile device and control the DNS prefetch manager so the DNS prefetch manager alters a level of the requests for the network addresses based upon the at least one operating condition. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    Various objects and advantages and a more complete understanding of the present invention are apparent and more readily appreciated by reference to the following Detailed Description and to the appended claims when taken in conjunction with the accompanying Drawings where like or similar elements are designated with identical reference numerals throughout the several views and wherein: 
           [0013]      FIG. 1  is a block diagram of a communication network according to several embodiments of the present invention; 
           [0014]      FIG. 2  is a block diagram depicting physical components of an exemplary communication device; 
           [0015]      FIG. 3  is a flowchart depicting an exemplary method; and 
           [0016]      FIG. 4  is a flowchart depicting another method. 
       
    
    
     DETAILED DESCRIPTION 
       [0017]    Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect(s) may be practiced without these specific details. 
         [0018]    In general, several embodiments of the present invention are directed to adapting DNS prefetching operations on a communication device to one or more operating conditions so as to provide the benefits of DNS prefetching (e.g., reduced user-perceived latency) while reducing any unintended adverse consequences from the prefetching operations. For instance, the level of DNS prefetching operations may be adapted to the network conditions so that the DNS perfecting does not interfere with other important communication traffic. For example, if a data rate to the communication device falls below one or more thresholds (e.g., because a WiFi network is unavailable and/or an estimated reverse link (“RL”) rate is low), DNS prefetching operations are reduced or eliminated altogether so as to prevent the DNS prefetching from interfering with other communications that are more critical to a user&#39;s experience and/or more critical to other operations on the communication device. 
         [0019]    As another example, the level of DNS prefetching may be adapted to a level of available power on the communication device so that the DNS prefetching is reduced as the available power on the communication falls (e.g., below one or more thresholds). 
         [0020]    And in some implementations, DNS prefetching operations are assigned a priority based upon operating conditions (e.g., network conditions and/or power conditions) so that DNS prefetching takes a lower priority relative to other RL traffic (e.g., HTTP GETS, TCP ACKS) so that the DNS prefetching does not interfere with other operations that are more critical to maintaining a desirable user-experience. 
         [0021]    Referring first to  FIG. 1  for example, shown is a block diagram depicting an exemplary communication network  100  in which many embodiments of the present invention may be implemented. As shown, the communication network  100  includes a remote server depicted as a content server  102  and a DNS server  104  in communication with a communication device  110  via a network  125 . 
         [0022]    The content server  102  generally represents one or more remote servers that operate to serve content (e.g., web content) that is requested by the communication device  110  (and potentially many other devices) via the network  125 . The network  125  may include the Internet, local area networks, cellular networks (e.g., a CDMA network, a GPRS network, a UMTS networks), and other types of communication networks. 
         [0023]    Webpages, as one of ordinary skill in the art will appreciate, typically include main pages and resources (e.g., objects) that are constituent elements the main page. In many instances for example, each webpage may include over one hundred objects including text, images, audio content, animation, video, and other content, which may be distributed over several separate servers that are in communication via the network  125 . And as one of ordinary skill in the art will appreciate, the resources that are associated with a particular webpage are discovered by parsing the webpage to obtain the URLs of the resources. 
         [0024]    The DNS server  104  represents one or more DNS servers that generally operate as part of the Domain Name System (DNS) to provide IP addresses of webpages and resources to the communication device  110  responsive to requests from the communication device  110 . For simplicity, the distributed nature of the DNS system is not depicted in  FIG. 1 , but one of ordinary skill in the art will appreciate that the DNS system includes several distributed servers that operated collectively to translate addresses from the domain name hierarchy namespace to IP address namespace responsive to DNS queries. 
         [0025]    Generally, the communication device  110  enables a user to retrieve content from the content server  102 , and the communication device  110  may be realized by a wireless communications device (WCD) such as a smartphone, PDA, netbook, laptop computer and other wireless devices. But the communication device  110  may work in tandem with wireline and wireless communication devices. 
         [0026]    More specifically, the communication device  110  in this embodiment includes an application  112  that is adapted to request content from the content server  102 . The application  112  may be realized by any of a variety of applications that access content from the content server  102  including web browsers, weather apps, navigation apps, gaming apps, financial apps, educational apps, and utility apps. For simplicity, the constituent components that may be utilized by the application  112  to access the network  125  and process content from the content server  102  (e.g., network interface, resource loaders, HTML parsers, rendering, layout, JavaScript engines, etc.) are not depicted, but these components are well known those of ordinary skill in the art. 
         [0027]    Also depicted in communication with the application  112  is a DNS prefetch manager  114  that is in communication with a history store  116 , a DNS cache  118 , and an adaptive DNS module  120 . The DNS prefetch manager  114  generally functions to resolve domain names, and store the associated IP addresses in the DNS cache  118 , before a user of the communication device  110  attempts to access content that is associated with the domain names. As a consequence, when a user (e.g., using application  112 ) does navigate to domain names that have already been resolved, the user need not wait for the application  112  to communicate with the DNS server  104  to resolve the domain names. 
         [0028]    In some embodiments, the DNS prefetch manager  114  preemptively resolves domain names of frequently accessed URLs that are identified by accessing the history store  116 , which includes a history of previously accessed URLs. The history store  116  may include a history store that is utilized by a browser and/or another history store that may be maintained by the DNS prefetch manager  114 . In addition, the DNS prefetch manager  114  may preemptively resolve domain names of links in a webpage that a user is viewing so that if the user navigates to one of the links, the domain names of the links are already resolved. 
         [0029]    Also shown is an adaptive DNS module  120  that generally operates to adapt the operations of the DNS prefetch manager  114  to one or more conditions that affect the communication device  110 . For example, the adaptive DNS module  120  alters the operation of the DNS prefetch manager  114  when DNS prefetch operations would adversely affect operation of the communication device  110 . 
         [0030]    As shown, the adaptive DNS module  120  may receive N inputs  122  (where N is one or more) that are indicative of environmental or on-device conditions. For example, the adaptive DNS module  120  may receive one or more inputs that are indicative of network conditions that the communication device  110  is operating under, and may include an indication of available power that remains on the communication device  110 . 
         [0031]    For example, when a data rate to the communication device  110  is low, the DNS prefetch operations may delay other communication traffic (e.g., HTTP GETS and TCP ACK communications) that are more critical to maintaining a quality user experience (e.g., maintaining a relatively low HTTP page down load time). As a consequence, the adaptive DNS module  120  may utilize one or more indicators of network conditions, which may include a rate that data is received at the communication device  110 . For example, a network condition indicator may be an indicator of an estimated reverse link (RL) rate of a 3G or 4G cellular network that is utilized by the communication device  110 . Another network condition indicator may also be an indicator of whether the communication device  110  is utilizing a WiFi network and/or may include an indicator of download rates of the WiFi network. 
         [0032]    Moreover, the adaptive DNS module  120  may assign a priority to DNS prefetch operations based upon the indicator(s) of network conditions to the adaptive DNS module  120  so that relative to other traffic that is more important to the quality of the user&#39;s experience and/or operation of the communication device  110 , the DNS operations are subordinated. For example, if a reverse link rate is very low, the adaptive DNS module  120  may assign a priority level to the DNS prefetching operations that is lower than a priority of HTTP GET and TCP ACK traffic. 
         [0033]    Referring next to  FIG. 2 , shown is a block diagram depicting physical components of an exemplary embodiment of a mobile device  200 . As shown, a power management component  210 , display portion  212 , and nonvolatile memory  220  are coupled to a bus  221  that is also coupled to random access memory (“RAM”)  224 , a processing portion (which includes N processing components)  226 , and a transceiver component  228 . Also shown is an energy storage portion  222  that is coupled to the power management component  210 . Although the components depicted in  FIG. 2  represent physical components of the mobile device  200 ,  FIG. 2  is not intended to be a hardware diagram; thus many of the components depicted in  FIG. 2  may be realized by common constructs or distributed among additional physical components. Moreover, it is certainly contemplated that other existing and yet-to-be developed physical components and architectures may be utilized to implement the functional components described with reference to  FIG. 1 . 
         [0034]    In general, the nonvolatile memory  220  functions to store (e.g., persistently store) data and executable code including code that is associated with the functional components depicted in  FIG. 1 . In some embodiments for example, the nonvolatile memory  220  includes bootloader code, modem software, operating system code, file system code, and processor-executable code to facilitate the implementation of one or more portions of the application  112 , DNS prefetch manager  114 , history store  116 , and adaptive DNS module  120  described with reference to  FIG. 1 . 
         [0035]    In many implementations, the nonvolatile memory  220  is realized by flash memory (e.g., NAND or ONENAND™ memory), but it is certainly contemplated that other memory types may be utilized as well. Although it may be possible to execute the code from the nonvolatile memory  220 , the executable code in the nonvolatile memory  220  is typically loaded into RAM  224  and executed by one or more of the N processing components  226 . 
         [0036]    The power management component  210  in the embodiment depicted in  FIG. 2  generally operates to provide the power indicator input to the adaptive DNS module  120  described with reference to  FIG. 1 , and the power indicator may include power capability information based upon a status of the energy storage portion  222 . In addition, the power management component  210  may operate as a power source to regulate the application of power to hardware components of the mobile device  200  and regulate charging of the energy storage portion  222 . In many implementations the energy storage portion  222  includes one or more rechargeable batteries (e.g., lithium-ion batteries), but it is certainly contemplated that the energy storage portion  222  may include other types of energy storage technologies (e.g., fuel cell or other technologies). The power capability information may include an indication of the amount of energy (e.g., in milliampere-hours (mAh)) that is available in the energy storage portion  222 . 
         [0037]    The N processing components  226  in connection with RAM  224  generally operate to execute the instructions stored in nonvolatile memory  220  to effectuate functional components depicted in  FIG. 1 . As one of ordinarily skill in the art will appreciate, the processing components  226  may include a video processor, modem processor, DSP, graphics processing unit (GPU), and other processing components. 
         [0038]    The depicted transceiver component  228  includes N transceiver chains, which may be used in connection with the application  112  to communicate with the content server  102  via the network  125 . As shown, each of the N transceiver chains includes transceiver components and a modem, and each transceiver chain represents a transceiver associated with a particular communication scheme. For example, one transceiver chain may operate according to wireline protocols, another transceiver may communicate according to WiFi communication protocols (e.g., 802.11 protocols), another may communicate according to cellular protocols (e.g., CDMA or GSM protocols), and yet another may operate according to Bluetooth protocols. Although the N transceivers are depicted as a unitary transceiver component  228  for simplicity, it is certainly contemplated that the transceiver chains may be separately disposed about the mobile device  200 . In some embodiments, one or more of the modems provides the network condition indicator(s) that are input to the adaptive DNS module  120 . For example, one or more of the modems may provide an estimate of the reverse link rate to the adaptive DNS module  120  and an indicator of the network conditions. 
         [0039]    The display  212  generally operates to provide visual images to a user that may include a user interface and content that is received in connection with many embodiments of the present invention. Although not depicted for clarity, one of ordinary skill in the art will appreciate that other components including a display driver and backlighting (depending upon the technology of the display) are also associated with the display  212 . 
         [0040]    Referring next to  FIG. 3 , it is a flowchart  300  depicting a method that may be traversed in connection with the embodiments described with reference to  FIGS. 1 and 2 . Although reference is made to  FIG. 1  and/or  FIG. 2  as examples of the components that may be utilized to carry out the method depicted in  FIG. 3 , the method is certainly not limited to the embodiments of  FIGS. 1 and 2 . 
         [0041]    As shown, before content is obtained from the content server  102 , the application  112  identifies resources that are associated with content located at the remote server  102  (Block  302 ). In the context of implementations where the application  112  is realized by a web browser, an initial request may be needed to obtain a main web page, which is then parsed to identify resources that are necessary to render the webpage. But if the application  112  is realized by an app, the list of resources may already be available on the communication device  110  (e.g., the resources may be stored in association with the application  112  in nonvolatile memory  220 ). 
         [0042]    As shown, before DNS prefetching (Block  312 ) is carried out, a rate of the reverse link is checked (Block  304 ) to determine if the rate of the reverse link is below one or more thresholds (Block  306 ) and a utilization of the reverse link is checked to determine whether a utilization of the reverse link (by traffic other than DNS prefetching) exceeds one or more thresholds (Block  308 ). In many modes of operation, the check of the reverse link rate (Block  304 ) is utilized to determine whether DNS prefetching (Block  312 ) is an option at all. For example, if the reverse link rate is below a particular level, even if there is no other traffic, DNS prefetching (Block  312 ) may not be a viable option at all. 
         [0043]    In contrast to the check of the reverse link rate (Block  304 ), the check of the reverse link utilization (Block  308 ) provides an indication of whether other traffic exists on the reverse link. For example, the reverse link rate may be sufficient to enable DNS prefetching, but traffic other than DNS prefetching may occupy a large percentage of the reverse link rate, and as a consequence, DNS prefetching may adversely affect the rate of the other traffic. For example but not by way of limitation, if the reverse link rate is 500 kbps and the reverse link utilization indicates that traffic other than DNS prefetching accounts for 495 kbps, DNS prefetching (Block  312 ) may interfere with other traffic that is more preferable to maintain than the DNS prefetching. 
         [0044]    As a consequence, in the method depicted in  FIG. 3  (and in many variations of this method) a priority is assigned to DNS prefetching relative to other traffic (Block  310 ). In some modes of operation, the priority that is assigned to the DNS prefetching is assigned based upon a status of the reverse link (e.g., the reverse link rate and/or utilization of the available rate). In some implementations, for example, DNS prefetching is not constrained by any priorities when the reverse link has relatively little traffic and is limited (e.g., by traffic priority) when the reverse link is heavily utilized so that DNS prefetching may, to a certain extent, level the load (e.g., fill in gaps of low utilization) on the reverse link. 
         [0045]    As shown, DNS prefetching is carried out (Block  312 ) based upon any prioritization that is applied to the prefetching, and the prefetched DNS information is then used to obtain the requested content (Block  314 ). 
         [0046]    Referring next to  FIG. 4 , it is a flowchart  400  depicting another method that may be traversed in connection with the embodiments described with reference to  FIGS. 1 and 2 . Although the method depicted in  FIG. 4  is separately depicted from the method described with reference to  FIG. 3 , the two depicted methods are certainly not mutually exclusive. 
         [0047]    As shown, in this method, as in the method described with reference to  FIG. 3 , before content is obtained from the content server  102 , the application  112  identifies resources that are associated with content located at the remote server  102  (Block  402 ). But in this method, an availability of power to the communication device  110  is obtained (Block  404 ), and DNS prefetching operations are carried out based upon the power that is available to the communication device  110  (Block  406 ). And the prefetched DNS information is utilized to obtain content if the content is requested (Block  408 ). 
         [0048]    In some implementations, the number of DNS prefetch queries that are sent varies in a general relation to the level of available power. For example, if the communication device  110  is connected to an external power supply (that provides substantially unlimited power), DNS queries may be preemptively performed without constraint, but if the external power supply is removed, the number of DNS queries that are performed may be reduced as the available power falls. And in some variations, once the available power falls to a threshold level, no further DNS queries are preemptively performed. For example without limitation, once the available power on the communication device  110  reaches 25% of capacity, no further preemptive DNS queries are carried out. Again, the 25% threshold is merely an example and it is certainly contemplated that other thresholds may be utilized, and that the threshold(s) may be configurable. 
         [0049]    As discussed, the method depicted in  FIG. 4  is not mutually exclusive with the method previously described with reference to  FIG. 3 . For example, in some instances, even if the communication device  110  is at, or near, 100% of available power, the reverse link data rate may be low enough such that unconstrained DNS prefetching may interfere with other important traffic. As a consequence, DNS prefetching may be reduced or omitted completely regardless of power level. 
         [0050]    While the foregoing disclosure discusses illustrative aspects and/or aspects, it should be noted that various changes and modifications could be made herein without departing from the scope of the described aspects and/or aspects as defined by the appended claims. Furthermore, although elements of the described aspects and/or aspects may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and/or aspect may be utilized with all or a portion of any other aspect and/or aspect, unless stated otherwise.