Abstract:
The delivery of content is improved from a user&#39;s perspective by encouraging the cache of user devices to maintain more current data prior to requesting web pages that would invoke the download of the more current data. A cache simulation of the cache in the user devices is maintained. When objects within the cache simulator are expected to require updating, actions are taken to encourage the user device to update the cache. The actions include modifying markup language files that are downloaded to the user device to invoke the update. For instance, artificial URL&#39;s that request the updated objects, embedded scripts, user selection objects, or the like are used to invoke an update process.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is being filed under 37 C.F.R. 1.53(b) as a non-provisional patent application and claiming the benefit of the filing date of U.S. Provisional Application for Patent filed on Aug. 4, 2006 and assigned an application Ser. No. 60/821,403. Such application is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates to data communication, and more particularly, to the field of browsing the Internet. 
     During the recent years, usage of data communication has increased. One popular method of data communication is surfing a network, such as but not limited to the Internet. The term “surfing” generally is defined as using a browser application to retrieve information embedded within web pages stored at one or more content servers. It should be noted that the terms “surfing” and “browsing” are used interchangeably herein. Surfing the Internet can be done by connecting a user to the Internet via an access network. An exemplary access network can be a wireless Internet service provider, a cellular service provider, satellite service provider, WiFi service provider, etc. A common data communication session can be based on a data communication protocol, such as but not limited to the Internet Protocol (IP). 
     A “Web page,” is a file or document created for use in the World Wide Web environment (hereinafter, “Web”). Web pages are typically located using a “URL,” which stands for Uniform Resource Locator, which is a form of address adapted for use in the distributed network environment of the Web. Web pages are typically encoded in a Markup Language (ML), such as but not limited to, Hyper Text Markup Language, or (HTML), Extensible Markup Language (XML), Wireless Markup Language (WML), XHTML, CHTML, WMLC, etc. Some of these languages can be used by cellular devices. A browser is a software application running on a user device that is adapted or functional to process Web documents. 
     In addition to web pages, other content pages may be created by using Markup Languages. These pages can be used over private networks, portals, organizational servers, etc. Henceforth, the description of the present invention may use the term ‘web page’ as a representative term for any of the above group or as general, displayable content created or defined by a Markup Language. 
     A common Web page includes a plurality of links to other pages or information. Some of the links are associated with objects of text as well as graphics, images, sound files, and perhaps video that belongs to the same web page. Usually those links are retrieved automatically by the browser while processing the current web page. The discloser of this application refers to those links as browser&#39;s links. Other links may be associated with other web pages, which are selected by the user according to his preference. Those links are referred as user&#39;s links or navigation links. 
     A common surfing session may start by requesting a home page of the portal that serves the user. For a user that uses a cellular device, for example, the home page of the portal can be the home page of the cellular service provider. In order to give a “homely” feeling to the surfer and to create a branding effect, the home page, as well as other pages of the portal, may have a stable site structure that may change infrequently. Furthermore, most of the pages in the portal include a logo that is associated with the portal, a similar navigation section, etc. that repeats in or is duplicated across two or more pages. In addition to the stable structure, changeable information may be added to the page. The changeable information can include items such as, but not limited to, news, advertising of local shops located close to the current location of the user, weather forecasting, etc. Fetching the home page and other pages of the portal may take a long time because a page can include images, graphics, etc. 
     To avoid re-fetching of the same information (repeating information) in next or future requested pages, a browser commonly uses a cache that stores the last received or most recently received information. However, common portal pages are configured to have a zero or very short expiration date, cache period, to reduce the risk of skipping and not displaying an update in the changeable information, such as in the news or advertisement. Therefore surfing the portal may take a long period of time, even though the portal may contain repeatable information. The long period of time adversely effects the user experience, especially when the user is connected via a long thin network (LTN). A LTN can represent a network having a limited bandwidth and/or high latency, such as but not limited to a cellular network, satellite, etc. 
     Therefore there is a need for a system and a method for enabling the use of cache within a user&#39;s device to eliminate the need for re-fetching of the same information of web pages and objects. Furthermore, there is a need for a technique for updating the information in the cache within a user&#39;s device, with changes to pages or information that occur between the times that the information is initially loaded into the cache of the user&#39;s device and the current time or the current status of the page at the portal. The operation of the system can be transparent to the user&#39;s device as well as to the web server that stores the web pages. 
     Such a new system can increase the quality of the user&#39;s experience by reducing the response time to a user&#39;s request. Accelerating the response can be achieved by updating its cache with the latest updates prior to requesting those updates. Pushing the updates can be done while the connection is not used for carrying a user&#39;s request or response to a last request. Transparent updates can be done during the time that a user reads a previously received page, for example. 
     BRIEF SUMMARY OF THE INVENTION 
     Different embodiments of the present invention solve the above-described needs by providing a system and/or method for managing a database housing an estimated replication of each one of the caches at the users&#39; devices. The estimated replication of a users&#39; caches can be referred to as a cache simulator. From time to time the cache simulator can be updated to include information that has been changed at a content server. The updated information can be rendered to update the user devices, and can be stored in the cache of the user devices prior to being requested by the user. 
     The system can intercept data communications between a surfer&#39;s device and a content server, such as but not limited to, a portal of the service provider. The system then modifies the expiration date of the page or object and sets it to a pre-configurable period, such as but not limited to tens of minutes up to a few days or even perpetual. The system then determines whether the cache of the user device requires updating and if so, pushes the required updated information toward the user device prior to receiving a relevant request. The updated information can be objects or pages. It should be noted that the terms “content server”, “web server”, “portal” and “server” may be used interchangeably herein. Henceforth, the description of embodiments of the present invention may use the term ‘server’ as a representative term for any of the above group or any other type of server that may be surfed by a user. 
     In one exemplary embodiment of the present invention, the process of checking whether a cache update session for a user&#39;s device is needed can be performed when a connection with the user&#39;s device is established. In alternate exemplary embodiment of the present invention, the decision can be performed periodically by examining the user&#39;s cache simulator, one after the other, in a cyclic mode. Yet in another embodiment of the present invention, the decision can be initiated by the server when a change in the server occurs, etc. 
     An exemplary embodiment of the present invention may push updated information (e.g. pages or objects) by reversing roles with the user device. Several methods can be used for pushing updated information. In one exemplary embodiment of the present invention, a transparent push method can be used. In a transparent push, a response to a requested web page may be modified to include a browser&#39;s link to a transparent object without adding a visual reference to this transparent object. The transparent object includes a URL that is not stored in the cache of the user&#39;s device. Therefore the transparent object will be requested by the browser of the user device. Upon receiving a request to deliver the transparent object, an embodiment of the present invention may deliver one or more objects that can be later requested, by the user, and are not included in the cache of the user device or the updated version of the one or more objects is not stored in the cache of the user device. 
     An alternate exemplary embodiment of the present invention may use a non-transparent-push method. When a non-transparent-push method is used, a requested web page is modified to include a selection object offering the user the option to update the cache of his device. Upon receiving a request to update the cache, an exemplary embodiment of the present invention responds by delivering one or more updated objects, using the multi-part option, or an ML file with a list of objects. 
     Other exemplary embodiments of the present invention may modify a response to a user&#39;s request and add a Java Script to the response. The Java Script is transparent to the user and automatically initiates a request for updates. 
     Furthermore, some embodiments of the present invention may learn the user&#39;s behavior in order to improve the user&#39;s experience. For example, an embodiment of the present invention may learn the time interval between consecutive requests of the user. A parameter, such as but not limited to, an average time interval between consecutive requests of the user can be used to define a maximum duration for pushing updates. 
     Additionally and/or alternatively, an embodiment of the present invention may learn the pattern of different flows. For example, one pattern reflects a common behavior of a user that goes from page ‘A’ to ‘B’, from ‘B to ‘D’ and from ‘D’ to ‘F’, etc. Based on such a pattern, an embodiment of the present invention may create an update cycle in the same order to deliver the most update information at the appropriate timing. Therefore when the user requests page ‘A’, the exemplary embodiment may update the cache with the new information embedded in page ‘B’, etc. Yet an alternative embodiment of the present invention may use any combination or all the above methods. Defining the combination may be dependent on the behavior of the user. Each user may have a different set of the above presented methods. 
     Exemplary embodiments can be transparent to the user&#39;s device as well as to the server. Other objects, features, and advantages of the present invention will become apparent upon reading the following detailed description of the embodiments with the accompanying drawings and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
         FIG. 1  illustrates a block diagram with relevant elements of an exemplary communication system that implements an exemplary embodiment of the present invention; 
         FIG. 2  illustrates a block diagram of relevant software modules of an exemplary embodiment of the present invention; 
         FIG. 3  illustrates a flowchart with relevant steps (processes) for handling a request cycle by an exemplary embodiment of the present invention; and 
         FIG. 4  illustrates a flowchart with relevant steps (processes) for handling a response cycle by an exemplary embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Turning now to the figures in which like numerals represent like elements throughout the several views, exemplary embodiments of the present invention are described. For convenience, only some elements of the same group may be labeled with numerals. The purpose of the drawings is to describe exemplary embodiments and not for production. Therefore features shown in the figures are chosen for convenience and clarity of presentation only. 
       FIG. 1  depicts a block diagram with the relevant elements of an exemplary communication system  100  that implements an exemplary embodiment of the present invention. A communication system  100  has been selected as an exemplary environment that is suitable for implementing exemplary embodiments of the present invention. The communications system  100  may be a cellular data communication network, satellite networks, access networks, Internet Service Provider (ISP), or other type of network or communication system. Within the context of this description, the terms cellular, satellites, wireless, and ISP may be used interchangeably and at times, may have the same meaning. 
     System  100  may comprise a plurality of terminals  110 ; communication links  120 ; a network operator center (NOC)  130 , a network  140  such as but not limited to the Internet, which can be referred also as the world wide web (WWW); and one or more Content Servers  142 . An exemplary NOC  130 , among other elements, may comprise a local communication unit  132 , a cache updater server (CUS)  134 , a router  138  and a portal  136  of the service provider. Exemplary embodiments of the present invention can refer to the portal  136  as one of the content servers  142 . Usually the data communication between the different elements of the NOC  130  is based on the Internet protocol. (IP). 
     It will be appreciated by those skilled in the art that depending upon its configuration and the needs, system  100  may comprise more than three Content Servers  142  and three terminals  110 . However, for purposes of simplicity of understanding, three units of each are shown. It should be noted that the terms “content server”, “web server” and “proxy server” may be used interchangeably herein. Henceforth, the description of embodiments of the present invention may use the term ‘server’ as a representative term for a content server a web server or a proxy server or any other type of server that may be surfed by a user. It should be noted that the terms “client”, “user&#39;s device”, “terminal”, “surfer” and “user” may be used interchangeably herein. 
     System  100  is based on the Internet Protocol (IP). System  100  may represent one or more networks segments, including but not limited to one or more Internet segments, one or more Intranets, etc. System  100  may run over one or more type of physical network, such as but not limited to, the Public Switched Telephone Network (PSTN), the Integrated Services Digital Network (ISDN), a cellular network (G2, G3 &amp; G3.5), a satellite network, etc. It may run also over a combination of these network types. System  100  may include intermediate nodes along the connection between a client  110  and a content server  142 . The intermediate node may include, but is not limited to, IP service provider servers, cellular service provider servers and other type of service providers equipments. 
     A plurality of terminals  110  may be served by the System  100  and capable of accessing the content servers  142  and/or the portal  136  via the NOC  130  and the Internet  140 . A common terminal  110  may run a browser software application in order to surf the network and to communicate with one or more content servers  142 / 136 . Exemplary, but not limited, browser applications can be the one available from Openwave Systems Inc. or OPERA MOBILE BROWSER, INTERNET EXPLORER, etc. Exemplary terminal  110  can be a personal computer (PC), a notebook computer, a cellular phone, handheld computer, a personal data assistant (PDA), or any other computing device with wire or wireless communication capabilities, etc. 
     The plurality of terminals  110  can be connected via a long thin network (LTN) of data links  120  to local communication unit  132  within the NOC  130 . The connection between the terminals  110  and the NOC  130  may be via intermediate nodes (such as a base station, etc.) not shown in  FIG. 1 . The local communication unit  132  acts as an access gateway between the network protocol that is used over the long thin network  120  and the IP network that is used over the NOC  130 . In some embodiments of the present invention, the local communication unit  132  may act also as an Authentication, Authorization, and Accounting (AAA) agent for the client  110 . Exemplary local communication unit  132  may be a Gateway GPRS Support Node (GGSN) or Packet Data Serving Node (PDSN) or any other similar network nodes. 
     Router  138  is the interface between the Internet  140  and the NOC  130 . Router  138  may route the upload communication toward the appropriate destination over network  140 . When the upload transportation is a request for content objects, router  138  routes the request to the appropriate content server  142 . In the download direction, the router  138  receives incoming packets from the different content servers  142  and distributes them to the appropriate modules of the NOC  130 . In a common NOC  130 , which does not utilize a CUS  134 , packets that are targeted toward a terminal are transferred to the local communication unit  132 . 
     An exemplary embodiment of cache updater server (CUS)  134  can intercept traffic being communicated between the local communication unit  132  and the router  138  and receive all the packets that are flowing between the local communication unit  132  and the router  138 . Therefore the CUS  134  receives the data transportation that is transferred between the plurality of terminals  110  and the plurality of the content servers  142 , as well as the data transportation that is transferred between the plurality of terminals  110  and the portal  136 . In one exemplary embodiment, the CUS  134  may be configured as the next hop for both sides of the NOC  130 , (i.e., for local communication unite  132  and for the router  138  as well as for the portal  136 ). 
     In another exemplary embodiment, the CUS  134  may physically reside between the local communication unit  132  and the router  138 . In both cases, the CUS  134  may be transparent to both sides of the connection, to the terminal  110  and/or to the content servers  142 / 136 . In an alternate exemplary embodiment of the present invention, the CUS  134  may use an HTTP proxy as an interface structure. In one embodiment, the HTTP proxy can be a transparent proxy. In an alternate exemplary embodiment, the HTTP proxy can be a non-transparent proxy. In such a case, the terminals  110  can be configured to communicate via the CUS  134 . Some exemplary embodiments of the present invention may use a redirector. The redirector can collect packets coming from the plurality of terminals  110  toward the plurality of the content servers ( 142 / 136 ) and redirect the packets toward the CUS  134 . An exemplary redirector can be a Content Inspection Director (CID) (a product of Radware Ltd, Israel). 
     The CUS  134  can manage a cache database that stores an estimated cache replication of the cache in terminals  110  (a cache simulator). From time to time the cache simulator can be updated to include information that has been changed at the one or more of the content servers  142  and or the portal  136 . The updated information can be rendered to the terminals  110 , thereby updating the cache within the terminals  110 , prior to the user making a request for the updated content from the content servers  142  or the portal  136 . 
     An exemplary CUS  134  can (a) intercept data communication between one or more of the terminals  110  and the one or more content servers  142 / 136 , such as but not limited to portal  136  of the service provider; (b) modify the expiration date of the requested or pre-fetched page or object to a pre-configurable period, such as but not limited to tens of minutes up to a few days or even forever; (c) determine whether the cache of the terminal  110  requires updating and pushing the required updated information toward the terminal  110  prior to receiving a relevant request from the terminal  110 . The updated information can include objects or pages. More information on the operation of the CUS  134  is depicted below in conjunction with  FIGS. 2, 3 &amp; 4 . 
       FIG. 2  is a block diagram depicting relevant elements of a cache updater server (CUS)  200  that operates according to an exemplary embodiment of the present invention. The illustrated CUS  200  may be associated with a NOC  130  ( FIG. 1 ) as an intermediate node between the local communication unit  132  and router  138 . In one exemplary embodiment of the present invention, the CUS  200  can be operative to follow sessions of surfing the portal  136  and/or one of the content servers  142 . The CUS  200  may record information that can be used for updating the content of the cache of the terminals  110  as well as information that may be used for scheduling or queuing pre-push updated objects or pages. Furthermore, the CUS  134  may modify downloaded markup language (ML) files that are targeted to the terminals  110 . Exemplary modifications can include, but are not limited to, (a) configuring the cache period value of relevant objects; and (b) adding additional browser&#39;s links to an ML file in order to force the browser applications, at the terminals  110 , to pre-fetch updated objects. 
     Among other modules, an exemplary CUS  200  may comprise an HTTP proxy  210 , a user&#39;s database (UDB)  250 , and a terminal cache application (TCA)  240 . An exemplary TCA  240  can be implemented as a web-application and among other logic modules, may comprise a learning module  244  and an ML file manipulator module (MMM)  244 . 
     In exemplary embodiments of the present invention in which the communication between the modules of the NOC  130  is based on IP, HTTP proxy  210  can be adapted to handle the first four layers of the OSI seven layer communication stack. The layers can be the Physical Layer 1, Link Layer 2, Network Layer 3, and the Transport Layer 4 (the TCP stack). In exemplary embodiments of the present invention, in which the CUS  200  is transparent to the terminal  110  ( FIG. 1 ), as well as to the content servers  136 / 142  ( FIG. 1 ), the HTTP proxy  210  may behave as a transparent proxy and may use a redirector, for example. The transparent HTTP proxy  210  can collect packets coming from the plurality of terminals  110  ( FIG. 1 ) toward the plurality of the content servers ( 142 / 136 ) and redirect requests and responses toward the web-application TCA  240 . In an alternate exemplary embodiment of the present invention in which the CUS  200  can be configured as an HTTP proxy at the terminals  110  ( FIG. 1 ), the redirector is not needed. 
     In the other direction (from the TCA  240 ), an exemplary HTTP proxy  210  can be adapted to get processed (modified) requests and/or responses from the TCA  240 ; to embed the modified requests and/or responses according to the communication protocol into IP packets and transmit the packets according to the destination address. The destination address can be the appropriate user via the local communication unit  132  ( FIG. 1 ). Alternatively, the destination address can be the portal  136  ( FIG. 1 ) or the appropriate content server  142  ( FIG. 1 ) via router  138 . 
     An exemplary UDB  250  can be a data base that can store an estimated replication of each one of the caches located in the terminals  110  (a cache simulator of each one of the terminals  110 ). The cache simulator can include the content of the objects that are assumed to be stored in the cache of the terminals  110 . In another embodiment of the present invention, a general cache is used as a logical part of the UDB  250 . The general cache stores (caches) the objects that were sent to all of the terminals  110 . In such an embodiment of the present invention, each cache simulator stores the location information, in the general cache, of objects that are assumed to be stored in the cache of each terminal  110 . 
     A user&#39;s table can be used for managing the UDB  250 . Each entry in the user&#39;s table can be associated with a user and may contain information such as, but not limited to, (a) an ID number of the terminal  110 , (b) the location in the UDB  250  that includes information that is relevant to the terminal  110 , (c) information on the current one or more connections, in which the user is currently involved; (d) the location of the user&#39;s cache simulator in the UDB  250 , etc. An exemplary ID number can be the MSISDN number. The MSISDN number can be retrieved from a notification that is sent by the local communication unit ( FIG. 1 ) to the appropriate modules of the portal  136  including the CUS  134 . Information on the relevant connection may include a URL that is associated with the connection. The UDB  250  and the user&#39;s table can be approached by different modules of the CUS  200  and is used in order to route information in between modules and to reach decisions during the operation of the CUS  200 . Therefore it may include status information, such as but not limited to: an indication on the updated data that needs to be pre-pushed to the user, an indication on the time to push an updated data, etc. 
     An exemplary TCA  240  can be adapted to check whether a cache of a user requires an update. The update decision can be based on an entry in the user&#39;s table that is associated with the terminal  110 . The user&#39;s cache table may contain information on the relevant objects that may exist in the cache of the terminal  110 . Each entry may have information, such as: (a) the URL of the object; (b) the date of the last update; (c) its cache period value; (d) the size of the object; (e) the location of the content of the object in the UDB, etc. Then, a decision is made whether the cache simulator for the terminal that is stored in the UDB needs an update of one or more stored objects. In one exemplary embodiment, the decision can be based on dates of the last update versus the cache period of each object. In another embodiment, an update can be done periodically. Yet in an alternate embodiment of the present invention the TCA  240  may re-fetch each stored URL, based on the user&#39;s table, from its original content server and then it may determine whether there are changes and whether an update is needed. Alternatively, or in addition, a content server, such as the portal  136  may inform the CUS  200  as to the changes. 
     Yet in another exemplary embodiment of the present invention, from time to time or in a cyclic mode, the TCA  240  may initiate an update task. The update task may retrieve the user&#39;s table and re-fetch the objects that are stored in the cache simulator in UDB  250 . An exemplary updating period can be few tens of minutes. Other embodiments may use any combination of the above-described methods, etc. 
     The TCA  240  receives requests and/or responses from the HTTP proxy  210  and analyzes the type of the request. The type can be a user&#39;s request for a page, an ML file that was sent as response to a request for a page, a request for an object, a response to an object request, etc. Based on the type of request, the TCA  240  may further process the requests or responses. Processing the requests or responses may include decisions on the surfing path that may be taken by the associated user. In order to determine an optional path, the TCA  240  may communicate with the LM  244  to collect information on the different options for next possible requests. The decision can be based on information that has been collected on the surfing procedure of the associated user. Such information can be retrieved from the relevant entry in the UDB  250 . For example, based on past experience the associated user may proceed from the NEWS web page to the SPORTS web page and from there to the FOOTBALL web page, etc. In addition, the decision may be based on a momentary trend that is relevant to the timing of the current surfing. For example, if the surfing occurs close to a certain huge event, then, although the user&#39;s common path is NEWS, SPORTS, FOOTBALL this time, the high probability will be NEWS and from there to the web page that reviews the huge event. 
     After reaching a decision on the best possible future requests, the requests or responses may be transferred toward its destination via the HTTP proxy  210 . If the data belongs to an ML file, information may be delivered by the LM  244  to the MMM  242  for further processing of the ML file. This information can be used later by the MMM  242  when determining which updated objects will be sent first. Then the ML file is transferred to the MMM  242  for further processing, etc. In addition, based on the type of the data, the TCA  240  may reach decisions about the cache that exists at the terminal  110 . 
     The MMM  242 , in its turn, may modify the ML file before forwarding it to the associated user. Several modifications can be performed on the ML file. One modification may include searching the ML file and changing the cache period value (the expiration date of the object) of the web page that is presented by the ML file as well as the cache period values of different objects that are embedded within the page. A second modification may be to add additional links (artificial links) to the ML file. The added links may point to URLs of objects that need to be pre-pushed in order to update the cache of the terminal  110 . The selected objects can be based on the information that was sent by the TCA  240 . Those updated objects are retrieved from the cache simulator for the terminal  110  in the UDB  250  and can be sent as an objects group (exemplary objects group can be multipart, archive, ZIP file, etc.) to the terminal  110  upon receiving a request to fetch an object from an artificial URL. In some embodiments of the present invention, future received ML files can be manipulated by the MMM  242  to include the artificial URLs. The artificial URLs can match the URL of the objects that were pushed to the cache of the terminal  110 . 
     In an alternate embodiment, the pre-fetched or updated objects can be sent as common objects and not as an objects group. The decision of using an objects group or a common object can depend on the type of browser being used at the terminal  110  (i.e., whether the browser can or can not handle objects group). 
     In one exemplary embodiment, the artificial links can lead to or address a transparent object without adding a visual reference to this transparent object. The transparent object has a URL that is not stored in the cache of the terminal  110 . Therefore, the artificial transparent object will be requested by the browser of the user device. The transparent URL can point to the location of the updated information in the cache simulator for the terminal  110  in UDB  250 . Upon receiving a request to deliver the transparent object, an embodiment of the present invention may deliver one or more objects that can be later requested, by the user and/or the browser running on the terminal  110 , and are not included in the cache of the terminal  110 ; or their updated version is not stored in the cache of the terminal. 
     Yet another exemplary embodiment of the present invention may use a non-transparent-push method. When a non-transparent-push method is used, a requested web page is modified by the MMM  242  to include a user selection object. The user selection object basically prompts or invites the user to select the selection object in order to update the cache. Upon receiving a cache update request, an exemplary embodiment of the present invention responds by delivering one or more objects that are needed for updating the cache of the terminal or by sending an ML file with a list of objects that are needed for the update. 
     The LM  244  may be used in order to collect browsing (surfing) procedures and trends and may include several predictive algorithms. The LM  244  may follow the browsing of a plurality of users  110  ( FIG. 1 ) and determine one or more optional browsing trees. The optional surfing paths, with or without their probability to be selected by a user, may be used by the TCA  240  to determine a queue of updated objects to be delivered to their associated users. More information on the operation of the TCA  240  is disclosed below in conjunction with  FIGS. 3 and 4 . 
       FIG. 3  illustrates relevant steps of an exemplary method  300  for handling a request cycle by an exemplary CUS  134  ( FIG. 1 ). Upon receiving a request, a decision is made  310  as to whether the request is an artificial one. An artificial request is a request that was initiated by a browser application, which is running at the terminal  110 , during a parse of a modified ML file in response to an artificial link that had been added by the MMM  242  ( FIG. 2 ) to the ML file. The decision can be based on the URL. If at step  310  it is an artificial request, then  316  the cache updated information that had been prepared by the TCA  240  ( FIG. 2 ) and had been stored in the artificial URL can be sent to the terminal via HTTP proxy  210  ( FIG. 2 ). In addition, information on this request can be transferred to the LM  244  in order to add information on the habits of the surfer. After sending the cache updated information the task can be terminated  320 . 
     If  310  it is not an artificial request, then  312  the request is transferred toward its destination (a content server  136 / 142 ,  FIG. 1 ). In addition, information on this request can be transferred  314  to the TCA  240  ( FIG. 2 ) in order to adapt the information on the cache of the terminal  110  accordingly and/or to the LM  244  ( FIG. 2 ). Information on such a request may indicate whether the user has changed his surfing habits—therefore the requested URL does not exist in his cache simulator, or that one of the assumptions on the cache in the terminal  110  is not correct (size of the cache for example) and is in need of being corrected. After updating the relevant modules the task can be terminated  320 . 
       FIG. 4  illustrates the relevant steps of an exemplary method  400  for handling a response cycle by an exemplary CUS  134  ( FIG. 1 ). Upon receiving a response, a decision is made  410  as to whether the response is a response to a CUS update request. A CUS update request is a request that was initiated by the CUS  200  ( FIG. 2 ) during a cache simulator update cycle. If  410  it is a response to a CUS update request, then  418  the information is stored in the cache simulator at an appropriate URL in the UDB  250  ( FIG. 2 ) and the TCA  240  ( FIG. 2 ) is updated accordingly. After storing the response in the cache simulator the task can be terminated  420 . 
     However, if the response  410  is not a response to a CUS update request, then  412  the response is stored in the cache database for the terminal (simulator) and the TCA  240  ( FIG. 2 ) is updated accordingly. If the response is an ML file of a requested web page, then the ML file can be manipulated  414  by the MMM  242  ( FIG. 2 ). Exemplary manipulations can modify the cache period value of the ML file itself and/or the cache period value of one or more embedded objects. Usually the cache period can be increased. In addition, one or more artificial browser&#39;s links can be added to the received ML file, as it is depicted above, in order to push the browser to fetch update objects in order to update the cache of the terminal  110 . In some embodiments of the present invention, the URL of objects that were pushed to the cache of the user device during an update session has a modified URL. In such embodiments, the manipulation of the ML file  414  may include searching for links to objects that have been pushed and replacing the original URL of the link to the modified one. The modified ML file is sent  416  toward the user via HTTP proxy  210  ( FIG. 2 ). If the response is not an ML file then method  400  skips step  414  and the response is sent  416  toward the terminal  110  without modification. After sending  416  the response, the task can be terminated  420 . 
     Furthermore, an exemplary embodiment of the present invention that includes a database with information on the cache of the terminal  110 , methods  300  and  400  may be modified. For example, method  300  may be modified to identify the type of terminal; to retrieve its parameters from the database and to adapt the operation of the TCA  240  ( FIG. 2 ) to match the parameters of the relevant cache. 
     Overall, this invention will improve the experience of a surfer during browsing the network and reduces the download time of a retrieved page. 
     In the description and claims of the present application, each of the verbs, “comprise” “include” and “have”, and conjugates thereof, are used to indicate that the object or objects of the verb are not necessarily a complete listing of members, components, elements, or parts of the subject or subjects of the verb. 
     In this application the words “unit” and “module” are used interchangeably. Anything designated as a unit or module may be a stand-alone unit or a specialized module. A unit or a module may be modular or have modular aspects allowing it to be easily removed and replaced with another similar unit or module. Each unit or module may be any one of, or any combination of, software, hardware, and/or firmware. It will be appreciated that the above-described modules may be varied in many ways, including, changing the number modules, combining two or more modules into one, dividing the operation of a certain module into two or more separate modules, etc. 
     It will be appreciated that the above described methods may be varied in many ways, including, changing the order of steps, and the exact implementation used. It should also be appreciated that the above described description of methods and apparatus are to be interpreted as including apparatus for carrying out the methods and methods of using the apparatus. 
     The present invention has been described using detailed descriptions of embodiments thereof that are provided by way of example and are not intended to limit the scope of the invention. The described embodiments comprise different features, not all of which are required in all embodiments of the invention. Some embodiments of the present invention utilize only some of the features or possible combinations of the features. Variations of embodiments of the present invention that are described and embodiments of the present invention comprising different combinations of features noted in the described embodiments will occur to persons of the art. The scope of the invention is limited only by the following claims.