Abstract:
A method manages an internet protocol address and time of validity. The method obtains ( 52 ) the IP address and validity time period for a mobile station ( 10 ). The IP address and validity time period are transmitted ( 53 ) to the mobile station ( 10 ). Prior to expiration of the validity time period the network ( 20 ) renews the IP address for a new validity time period.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    The present invention pertains to internet networks and more particularly to a method for managing dynamic internet address leasing.  
           [0002]    Mobile stations or handsets may connect to the internet to activate certain applications through various servers. To access the internet, an Internet Protocol address is required. Internet Protocol addresses are typically stored within the handset for a time period. These Internet Protocol addresses are leased, that is they are available for use for a certain time. Mobile handsets may go off the air for some time and not interconnect to reestablish a new Internet Protocol address before the old Internet Protocol address expires.  
           [0003]    Requiring the mobile handset to renew its address requires considerable amounts of air time and interface with the internet. Establishing or reestablishing a new Internet Protocol address is “expensive” in terms of air time required of a mobile handset.  
           [0004]    In addition, applications serving mobile handsets need a reliable validity time for Internet Protocol addresses dynamically assigned to handsets. And handsets need to know their own address validity time so they can provide the time in application registrations.  
           [0005]    Accordingly, what is needed is a method for managing Internet Protocol address lease time for mobile users.  
       
    
    
     DESCRIPTION OF THE DRAWING  
       [0006]    [0006]FIG. 1 is a block diagram of a handset interconnection for supporting mobile Internet Protocol in accordance with the present invention.  
         [0007]    [0007]FIG. 2 is a message flow diagram of an Internet Protocol address management by the network in accordance with the present invention.  
         [0008]    [0008]FIG. 3 is a message flow diagram of an Internet Protocol address request for a time extension in accordance with the present invention.  
         [0009]    [0009]FIG. 4 is a message flow diagram of a mobile unit request for an extension of time of an Internet Protocol address in accordance with the present invention.  
         [0010]    [0010]FIG. 5 is a message flow diagram of a network request to a handset for renewal of an extension of time for an Internet Protocol address in accordance with the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0011]    Referring to FIG. 1, a block diagram of a mobile handset  10  access to the network  20  is shown. Mobile station or handset  10  transmits a Packet Data Protocol (PDP) context activation  15  to get a dynamic Internet Protocol address from mobile network gateway (MNG)  20  (for GPRS services that is the Gateway GPRS Support Node or GGSN). In response MNG  20  may either allocate an address from a pool of addresses owned by the gateway or request an address  21  from a separate server such as a Dynamic Host Configuration Protocol (DHCP) server  50 . If the address is allocated from a pool of addresses owned by the gateway, the gateway determines the time limit on the address. If the address is retrieved from a separate server  50 , that server  50  provides the address and the time limit on the address.  
         [0012]    If the handset  10  provided a name to be registered, the gateway also makes a DNS registration request  25  to Domain Name Server  30 . The gateway includes the address and time limit with the handset name as part of the registration request.  
         [0013]    Internet ProtocolMobile network gateway  25  returns the internet address and time limit on the address via the activation link  15  to handset  10 . Handset  10  may then register for services with the application server/client via direct application level registration  45 . The handset  10  may also rely upon the application server/client  40  to retrieve the handset  10  Internet Protocol address and time from Domain Name Server  30  via a DNS query  35 . This query  35  will then provide application server/client with the Internet Protocol address of handset  10  and the time for which that Internet Protocol address is valid.  
         [0014]    When a handset requests a PDP activation, if a dynamic Internet Protocol address is assigned as part of the activation, then the present invention adds capability in the handset to receive the expiration time and to make requests of the network from (?) management of the IP address and the expiration time.  
         [0015]    Referring to FIG. 2, a message flow diagram for a mobile handset dynamic Internet Protocol address activation and management is shown. Handset  10  transmits an activate PDP context request  51  to the MNG  20 . The mobile network gateway  20  may already have a pool of IP addresses and if so, will send an address back to handset  10 . If the MNG  20  does not have a local pool of IP addresses, MNG  20  will retrieve an IP address and time of activation from Dynamic Host Configuration Protocol (DHCP) server  50  via a request for address  56 . This request will provide the IP address and a time for which the IP address is valid.  
         [0016]    If there is a name to be registered for this handset (either provided directly by the handset or provisioned into the mobile network), the MNG  20  will request registration  52  and provide the name, IP address and time for which the IP address is valid to the Domain Name Server (DNS) as part of the registration request.  
         [0017]    If either the MNG  20  had a pool of available IP addresses or received one from the DHCP server  50 , gateway  20  will respond to handset  10  with an activate PDP response  53  which includes the IP address and the time the address is valid.  
         [0018]    The handset  10  may register its IP address to applications  40  to contact the handset at a later time. This allows the application  40  to know the IP address required to communicate with the handset and the validity time for that address.  
         [0019]    As time passes, the validity of the handset  10  IP address is reaching the end of its time. Since the MNG  20  has been given the ability to store the handset name, IP address and expiration time, the MNG  20  will either renew the address time in its internal address pool or submit a renew address request to DHCP  50  via message  57 . If MNG  20  requested address time renewal from DHCP server  50 , server  50  will respond with an authorization for renewal and extension of time.  
         [0020]    After the address time has been renewed, if the handset has a name registration to maintain, MNG  20  will submit a renew address/name registration request to DNS  30  via message  54 .  
         [0021]    MNG  20  will then modify the PDP information and transmits to handset  10  via message  55  the new expiration time for the associated IP address when the handset is logged on to the network. Thereby the “lease time” for the Internet Protocol address has been extended without intervention of the handset  10 .  
         [0022]    Internet ProtocolThis invention would include passing the handset name, optionally, and returning the validity time of the IP address to the handset. As a result, the handset does not have to “log in” and “log off” to the network whenever its IP address time expires nor does the handset need to monitor the validity time of the IP address. This takes several interactions of the handset and considerable air time to achieve these administrative “log on” and “log offs”. As a result, air time is minimized and cost is saved. Also, battery life of the internet handset  10  may be extended.  
         [0023]    [0023]FIG. 3 is a message flow diagram of the lease time renewal for handset  10  IP address. MNG  20  transmits renewal address/name registration  61  to the Domain Name Server  30 . The registration renewal  61  includes the handset name, IP address and the previous time of expiration for handset  10 .  
         [0024]    Next, MNG  20  transmits a modify PDP message which gives the new expiration time for the IP address to handset  10 . The new expiration time selected for the IP address may be a default value; may be a percentage of the time associated with the initial request; based on a system parameter, such as capacity for example; or it may be based upon the user profile of the particular handset.  
         [0025]    Once the handset  10  has the new time for expiration of the IP address, handset  10  may communicate directly with application server/client  40  via an application registration  63 . Or, alternatively, application server client  40  may make a direct DNS query to retrieve the handset&#39;s IP address. If the application server client  40  made a DNS query, it will then receive a DNS reply which includes the IP address of the handset and the new time remaining  65 .  
         [0026]    [0026]FIG. 4 is a message flow diagram of a IP address lease renewal initiated by handset  10 . Handset  10  transmits a modify PDP request  71  to MNG  20 . This request will include the new lease time requested. If the MNG  20  is able to honor the request from its pool of IP addresses, it will do so. If the address was not allocated by the MNG or if the address pool is unavailable, MNG  20  will transmit a renew address request  77  to DHCP server  50 . This request will include the IP address in use by the handset and the time requested for validity of the IP address. DHCP server  50  will respond with the time granted and IP address to MNG  20  via response message  77 .  
         [0027]    If the handset has a name, MNG  20  will transmit a renew address/name registration  72  to Domain Name Server  30 . This message will include the handset name, the IP address of handset  10  and the time for validity of the IP address. Domain Name Server  30  will acknowledge the request to MNG  20  via response message  72 .  
         [0028]    MNG  20  will then return the new time validation to handset  10  via the modify PDP response  73 .  
         [0029]    Handset  10  may then directly make an application of registration  74  at the application server client  40 . Or an application server  40  can request a DNS query  75  of the Domain Name Server  30  at any time. Domain Name Server  30  will then provide a DNS reply  76  to application server providing the IP address of handset  10  and the valid time for that address.  
         [0030]    Again, the extended time granted by the MNG  20  or the DHCP server  50  may be based on a default value; percentage of the initial time request; based upon a system parameter, such as capacity for example; or based upon a particular user profile for the handset.  
         [0031]    As can be seen, the arrangement of FIG. 4 provides an alternate means of generating the request for a renewal of the time validity of the IP address. The handset  10  may directly control initiation of this as opposed to the previous method of permitting the MNG or network  20  to automatically control the time request.  
         [0032]    Referring to FIG. 5, a message flow diagram for an IP address management is shown. Similar to the previous method, handset  10  produces an activate PDP request  81  to MNG  20 . This request includes a request for time for the associated Internet Protocol address. MNG  20  either allocates an address from its own address pool or requests an address from the DHCP (Dynamic Host Configuration Protocol) server  50  with the time provided by the handset in Internet Protocoladdress request message  82 . DHCP server  50  then responds to MNG with the time granted via message  82 . MNG  20  then returns the IP address and expiration time back to the handset  10  via activate PDP response  83 .  
         [0033]    When the validity time of the IP address is about to expire, MNG  20  renews the address either using its own address pool or via renewal address message  84  to DHCP server  50 . Prior to the expiration of the IP address validity, MNG  20  sends a modify PDP message  85  including the new time the IP address is valid to handset  10 . If handset  10  either is not available to receive the modify message  85  or does not respond to the modify message  85 , MNG  20  initiates deactivation of the IP address.  
         [0034]    As can be seen from the above explanations, a number of methods have been shown for automatically or semi-automatically extending the time of an IP address for a mobile handset. This may be accomplished automatically by the network, automatically under direction of the handset or automatically by the network with verification of the handset&#39;s active status. Great amounts of system overhead, air time and costs may be saved as a result of these methods.  
         [0035]    Although the preferred embodiment of the invention has been illustrated, and that form described in detail, it will be readily apparent to those skilled in the art that various modifications may be made therein without departing from the spirit of the present invention or from the scope of the appended claims.