Abstract:
A method and apparatus is provided for implementing initial network entry procedures by a Femto access point which is required to be authenticated by the WiMAX network prior to becoming active and operational. The method includes implementing a DNS query to discover an associated server and gateway in an associated Femto network service provider domain and obtaining an IP address for the server and an IP address for the gateway. The method also includes authenticating the Femto access point with the associated Femto network service provider and establishing a secure IP tunnel between the Femto access point and the gateway. The method further includes interacting with a default self organizing network server to perform location authorization, wherein the self organizing network server is configured to auto configured the Femto access point with preliminary radio parameters. The method also includes executing registration with a Femto gateway. The apparatus includes associated components for implementing the method described above.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The present invention is directed to a system and method for performing initial network entry procedures of an integrated or non-integrated femto access point (WFAP), wherein the WFAP is required to be authenticated by a WiMAX network prior to becoming active and operational. 
         [0003]    2. Description of the Related Art 
         [0004]    An embodiment of the WiMAX network architecture for femtocell systems is based on the WiMAX basic reference network model that differentiates the functional and business domains of network access providers (NAPs) from those of the network service providers (NSPs).  FIG. 1  illustrates a prior art representation of network operators relationships in the WiMAX basic reference network model. Each NAP  102  is a business entity that provides WiMAX radio access infrastructure to one or more NSPs  104 . Each NSP  104  is a business entity that manages users&#39; subscriptions and provides IP connectivity and WiMAX services to subscribers according to negotiated service level agreements. To provide these services, each NSP  104  establishes contractual agreements with one or more NAPs  102 . An NSP  104  may also establish roaming agreements with other NSPs and contractual agreements with third party application service providers (ASPS)  106  for providing IP services to subscribers. 
         [0005]    Logical network entities for NSP  104  and NAP  102  include a connectivity serving network (CSN) and an access serving network (ASN), respectively. NAP  102  is deployed as one or more ASNs, which are composed of ASN gateways and base stations. NSP  104  is deployed as CSN and may include a home agent, authentication, authorization, and accounting (AAA), and other relevant servers and databases. 
         [0006]    In a WiMAX network supporting a femtocell, a femto-NSP is responsible for the operation, authentication, and management of femto access points (WFAPs). The femto-NSP is logically separated from the conventional WiMAX NSPs responsible for mobile stations subscriptions, and it includes femto-AAA and femtocell management/self-organizing network (SON) subsystems. (See  FIG. 2  below for further discussion of a WiMAX network supporting a femtocell) 
         [0007]    The necessary procedure for attaching a WFAP to the WiMAX network is dependent on the physical composition of the WFAP associating with a broadband access device (e.g. DSL or Cable modem). The procedure for attaching the WFAP to the WiMAX network is also dependent on the Femto-NSP and the Femto-NAP network operational policies. If the WFAP is an integrated WFAP, and the broadband access operator is the same operator as the Femto-NSP, the Femto-NSP may prefer to by-pass the WFAP mutual authentication process with the WiMAX network during the initial network entry procedure. This is because the WFAP would have been authenticated and authorized during prior broadband access network entry procedures. As is known to those skilled in the art, an integrated WFAP integrates the WFAP functions with a broadband interface (e.g. DSL or Cable Modem) into a single physical device. 
         [0008]    In a non-integrated WFAP, the WFAP and the broadband interface (e.g. DSL or Cable Modem) are maintained as two different physical devices. The connection between the WFAP and the broadband device is based on an opened interface. A Non-WiMAX Authenticated WFAP is an integrated WFAP which is not required to be authenticated over the WiMAX network by the Femto-NSP. Note that, an integrated WFAP does not imply that it is not required to be authenticated over the WiMAX network by the Femto-NSP. The decision to authenticate an integrated WFAP, by the Femto-NSP, is an operator based decision, depending on deployment. A WiMAX Authenticated WFAP can be an integrated WFAP or a non-integrated WFAP which is required to be authenticated by the Femto-NSP over the WiMAX network. 
         [0009]    A problem to be solved by embodiments of the present invention is directed to the initial network entry procedures of an integrated or non-integrated WFAP which is required to be authenticated by the WiMAX network prior to becoming active and operational. 
       SUMMARY OF THE INVENTION 
       [0010]    An embodiment of the present invention is directed to the initial network entry procedures of the WFAP, integrated or non-integrated WFAP, which is required to be authenticated by the WiMAX network prior to becoming active and operational for associated Femto subscribers. 
         [0011]    An embodiment of the present application is directed to a method and apparatus for implementing initial network entry procedures by a Femto access point which is required to be authenticated by the WiMAX network prior to becoming active and operational. The method includes implementing a DNS query to discover an associated server and gateway in an associated Femto network service provider domain and obtaining an IP address for the server and an IP address for the gateway. The method also includes authenticating the Femto access point with the associated Femto network service provider and establishing a secure IP tunnel between the Femto access point and the gateway. The method further includes interacting with a default self organizing network server to perform location authorization, wherein the self organizing network server is configured to auto configured the Femto access point with preliminary radio parameters. The method also includes executing registration with a Femto gateway. The apparatus includes associated components for performing the described method. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  illustrates a prior art representation of network operator relationships in a WiMAX basic reference network model; 
           [0013]      FIG. 2  illustrates an embodiment of WiMAX Femto network reference model with SON functions; and 
           [0014]      FIG. 3  illustrates the steps implemented in an embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0015]      FIG. 2  illustrates an embodiment of WiMAX Femto network reference model with SON functions. As illustrated in  FIG. 2 , mobile station  201  is connected to the NAP  202  of the femtocell through femto access point (WFAP)  205 . As noted above, a femto-NSP  204  is responsible for the operation, authentication, and management of WFAPs  205 . Femto-NSP  204  is logically separated from the conventional WiMAX NSPs  104  which is responsible for mobile stations subscriptions. Femto-NSP  204  includes femto-AAA  207  and femtocell management/self-organizing network (SON)  208  subsystems. 
         [0016]    According to an embodiment of the present invention, the general call flow for WiMAX authenticated WFAP  205  includes four phases: (1) Configuration Server Discovery Phase, (2) WFAP WiMAX Authentication Phase, (3) SON Location Authorization and preliminary radio system parameters Auto-Configuration Phase, and (4) Femto-GW Registration Phase. 
         [0017]    In Phase  1  or the Configuration Server Discovery Phase, if a serving DHCP server and the serving SeGW  206 , associated with WFAP  205  for the corresponding the Femto-NSP  207  have not been pre-configured to WFAP  205 , the serving DHCP server and the serving SeGW  206  in the Femto-NSP domain is discovered via the support of DNS. Optionally, the SON server  208  may also be discovered in this phase. Note that, the network access identifier and the full qualified domain name (NAI/FQDN) would have been available for WFAP  205  to trigger the DNS query. 
         [0018]    According to an embodiment of the invention, in this phase, WFAP  205  is connected to the IP broadband backhaul and uses DHCP specific procedure to acquire the IP address configured by the IP broadband operator to get access to the Internet. During this procedure, WFAP  205  may acquire the default SeGW  206 , and optionally the default SON server&#39;s  208  IP, but it is out of WiMAX femto scope. WFAP  205  performs the discovery procedures for the associated serving DHCP server and serving SeGW  206  corresponding to Femto-NSP  204  via the support of DNS and WFAP  205  obtains the default serving SeGW&#39;s IP address, and the default serving DHCP server&#39;s IP address. WFAP  205  may optionally obtain the default serving SON Server&#39;s IP address. 
         [0019]    As noted above, the NAI/FQDN would have been available for the WFAP to trigger the DNS query. It should be noted that if the WFAP obtains more than one SeGW IP addresses in this phase, then WFAP  205  may choose one of them as the default SeGW  206 . Similarly, if WFAP  205  gets more than one SON server (SON Function) IP addresses in this phase, and then WFAP  205  may choose one of them as the default SON server  208 . 
         [0020]    In Phase  2  or the WFAP WiMAX Authentication Phase, WFAP  205  is authenticated by the Femto-NSP  204  through the support of SeGW  206  which hosts the Anchor Authenticator of WFAP  205 . In this phase, through the support IKEv2, an IPSec tunnel is established between WFAP  205  and SeGW  206 . In an embodiment of the present invention, in this phase, the WFAP connects to the default serving SeGW  206  which hosts the Anchor Authenticator of WFAP  205 , and performs the authentication with the Femto-AAA  207 . In the first step of this phase, the authentication process is performed between WFAP  205  and the Femto-AAA  207  via SeGW  206 . Femto-AAA  207  checks whether WFAP  205  is an authorized subscriber based on the WFAP identification pre-assigned NAI. During the authentication procedure, Femto-AAA  207  may assign a SON server (SON Function)  208  to WFAP  205  if no SON server has been assigned to WFAP  205 . The Femto-AAA may also assign a Femto-GW  210  to the WFAP. It should be noted that after Femto-AAA  207  assigns a SON server to WFAP  205 , WFAP  205  uses the assigned SON server as the default SON server  208 . 
         [0021]    In the second step of this phase, after the successful completion of authentication between WFAP  205  and Femto-AAA  207 , the IPSec tunnel establishment process is performed between WFAP  205  and SeGW  206 . It should be noted that when WFAP  205  tries to connect to the default SeGW  206 , the SeGW redirection procedure may happen (e.g. due to load balancing) and then WFAP  205  will connect to a new SeGW. It should also be noted that if WFAP  205  is a WiMAX non-authenticated WFAP, then the entire phase  2  can be omitted for WFAP  205 . 
         [0022]    In Phase  3  or the SON Location Authorization and preliminary radio system parameters Auto-Configuration Phase, an optional SON Server Discovery via the configuration provided by DHCP server or by Femto-AAA  207  may be performed. A WFAP Location Authorization, via the support of the SON function, and preliminary radio system parameters auto-configuration, via the support of the SON function, are also performed. According to an embodiment of the invention, in this phase, the WFAP performs SON server discovery and connects to the default SON server residing in the Femto-NSP  204  to perform the location authorization and to auto-configure the preliminary radio parameters. 
         [0023]    In Step  1 , the WFAP may obtain another IP address configured by Femto-NSP  204  to operate within the Femto-NSP  204  network domain. During this procedure, WFAP  205  may also be assigned a SON server  208  (SON function), if none has been assigned to the WFAP, in the Femto-NSP domain, and optionally, the serving Femto-GW  210  may also be assigned if none has been assigned. Note that if WFAP  205  does not need a Femto-NSP configured IP address, but if WFAP  205  obtains neither the default SON server (SON function) IP address nor the FQDN, WFAP  205  can also trigger the DHCP specific procedure with the serving DHCP server to acquire a SON server (SON function) IP address. 
         [0024]    In Step  2 , if WFAP  205  has the SON server FQDN, but not the IP address, then WFAP  205  can perform the DNS query procedure with the DNS server which resides in the Femto-NSP domain. During this procedure, WFAP  205  can get the SON server IP address. 
         [0025]    In Step  3 , WFAP  205  interacts with the default SON server in Femto-NSP  204  to perform the WFAP&#39;s location authorization, and based on the location information of WFAP  205 , SON server  208  may assign a Femto-GW  210  to WFAP  205 . 
         [0026]    In Step  4 , SON server  208  can auto-configure WFAP  205  with preliminary radio parameters. It should be noted that based on the location authorization, SON server  208  in the Femto-NSP can determine to which NAP WFAP  205  should connect. The location authorization function which is a part of the SON function should reside in the Femto-NSP domain. 
         [0027]    In Phase  4  or the Femto-GW Registration Phase, (1) Femto-GW  210  assignment to the WFAP  205  can be specified by the configuration parameters provided by the serving DHCP server, by the serving Femto-AAA  207  or by the serving SON function; and (2) WFAP R6-F establishment with Femto-GW  210  is completed. In this stage, WFAP  205  connects to the appropriate Femto-GW  210  to execute the Femto-GW registration. After this stage, the WFAP will go into the base station mode. 
         [0028]    In Step  1 , NAP (SON function in the NAP) coordinates with the Femto-NSP (SON function in the NSP) to perform auto-configuration. In Step  2 , WFAP  205  performs Femto-GW registration with the default Femto-GW  210 . Then Femto-GW  210  becomes WFAP  205  serving Femto-GW. In addition, the Femto-GW may redirect WFAP  205  to another Femto-GW for the purpose of the load balancing or other optimization reasons. Note that during the Femto-GW registration, the Femto-GW may need to contact WFAP&#39;s SON function which resides both in NAP and Femto-NSP to exchange some information. 
         [0029]      FIG. 3  illustrates the steps implemented in an embodiment of the present invention. In Step  1  of Phase  1 , if a serving DHCP server and the serving SeGW  206  have not been pre-configured to WFAP  205 , the serving DHCP server and the serving SeGW  206  in the Femto-NSP domain is discovered via the support of DNS. 
         [0030]    In Step  1  of Phase  2 , WFAP  205  is authenticated by the Femto-NSP  204  through the support of SeGW  20 . 6  which hosts the Anchor Authenticator of WFAP  205 . In Step  2  of Phase  2 , after the successful completion of authentication between WFAP  205  and Femto-AAA  207 , the IPSec tunnel establishment process is performed between WFAP  205  and SeGW  206 . 
         [0031]    In Step  1  of Phase  3 , WFAP  205  may obtain another IP address configured by Femto-NSP  204  to operate within the Femto-NSP  204  network domain. In Step  2  of Phase  3 , if WFAP  205  has the SON server FQDN, but not the IP address, then WFAP  205  can perform the DNS query procedure with the DNS server which resides in the Femto-NSP domain. In Step  3  of Phase  3 , WFAP  205  interacts with the default SON server in Femto-NSP  204  to perform the WFAP&#39;s location authorization, and based on the location information of WFAP  205 , SON server  208  may assign a Femto-GW  210  to WFAP  205 . In Step  4  of Phase  3 , SON server  208  can auto-configure WFAP  205  with preliminary radio parameters. 
         [0032]    In Step  1  of Phase  4 , Femto-GW  210  assignment to the WFAP  205  can be specified by the configuration parameters provided by the serving DHCP server, by the serving Femto-AAA  207  or by the serving SON function. In Step  2  of Phase  4 , WFAP  205  connects to the appropriate Femto-GW  210  to execute the Femto-GW registration. 
         [0033]    Although the present invention has been shown and described with respect to certain embodiments, it should be understood by those skilled in the art that various modifications can be made to the inventive apparatus and the method of operating the same of the invention without departing from the scope and spirit of the invention. It is intended that the present invention cover modifications and variations of the inventive device and method provided they come within the scope of the appended claims and their equivalents.