fig7 is a functional block diagram of an architecture of a combined gan - gsm - femto access network 50 suitable for use in implementing the present invention . to develop an access solution with advantages over either the gan solution or the gsm - femto solution , one can combine the two solutions , utilizing the best properties of each . the combined solution allows existing mss to be utilized because the um - interface is used between the ms 11 and a modified femto cell cpe 51 . the femto cell cpe in the combined solution is modified to include a gan - client , enabling the up - interface to be used to connect the femto cell cpe 51 to the ganc 13 . the standardized up - interface requires some modifications , and thus a so - called up + interface is utilized . the ganc uses the normal gsm interfaces towards the cn 15 and the other support nodes as in the normal gan solution . fig8 is a protocol diagram illustrating a cs domain control plane architecture 60 related to the combined gan - gsm - femto access network of fig7 . the femto cell cpe 51 is extended both with bsc functionality 61 and with a gan - client 62 . the bsc functionality is needed to terminate the gsm rr protocol from the ms 11 and the gan - client is needed to interwork between gsm rr and the ga - csr protocol . the ganc 13 then interworks between the ga - csr and the bssap protocols . the security solution applied for the gan - gsm - femto network 50 is very similar to the solution used in gan and in gsm - femto . the femto cell cpe 51 establishes an ipsec tunnel to the segw 14 using the same mechanisms as in gan . the main difference towards gan is that the femto cell cpe contains the ( u ) sim card that is authenticated towards the aaa server 25 ( and this is exactly the same as in the gsm - femto solution ). fig9 is a functional block diagram of an architecture of a gan - wcdma - femto access network 70 suitable for use in implementing the present invention . in this case , the normal lu interface is utilized between the ganc and the mobile core network side and the air interface to the mss is the uu - interface . a modified femto cell cpe 71 is modified to include utran radio network controller ( rnc ) functionality . fig1 is a protocol diagram illustrating a cs domain control plane architecture 80 related to the wcdma - femto access network of fig9 . as noted , the modified femto cell cpe 71 is modified to include utran rnc functionality in the radio resource control ( rrc ) 81 , radio link control ( rlc ) 82 , and media access control ( mac ) 83 layers . fig1 is a signaling diagram illustrating two different types of gan registrations performed by the femto cell cpe 51 towards the ganc 13 . the two types of registrations are called cpe gan registration and ms gan registration . the cpe gan registration is performed when the femto cell cpe 51 is powered on and the associated femto cell is created . after the femto cell cpe 51 sends a ( cpe ) ga - rc register request message to the ganc 13 , the ganc returns a ( cpe ) ga - rc register accept message with gan system information needed for femto cell setup by the femto cell cpe . the ms gan registration is performed by the femto cell cpe 51 when it detects that an ms 11 is trying to access the femto cell . this normally happens when the ms performs a location updating procedure via the femto cell because the femto cell has a different location area identifier ( lai ) compared to macro cells in the area . after the femto cell cpe 51 sends a ( ms ) ga - rc register request message to the ganc 13 , the ganc returns a ( ms ) ga - rc register accept message with gan system information . after this , the ms can access services provided by the ganc , i . e ., the ms has access to both the msc and the sgsn . the ganc 13 is able to combine these two procedures . in other words , the ganc is able to find out that the ms gan registration relates to a specific cpe gan registration ( since the same ipsec tunnel is used ). the present invention relates to the use of common nodes in the different embodiments described above . the common nodes and related principles as follows : all the embodiments described herein utilize ipsec tunnels to access the network . these ipsec tunnels are established between the ms 11 and segw 14 ( in gan ) or between the home access point ( hap , e . g . femto cell cpe ) and the segw . this means that the segw is one common node between these embodiments . the different embodiments , however , have different types of security requirements that the segw must enforce on the ipsec tunnels . these requirements are related for example to the number of tcp connections / udp - streams in the tunnel or total bandwidth allowed in the tunnel . one clear reason for the differences is that in gan , there is a single ipsec tunnel for each ms , and in the other solutions , all the mss accessing one hap share the same ipsec tunnel . there are standardization efforts ongoing for solutions other than gan that use the segw 14 , and all solutions include some form of gateway or controller node for controlling ms registration . although the present invention is described herein in terms of the gan , it should be understood that the invention is applicable to any type of gateway or controller node that controls ms registration and communicates with the segw . the gan , the gan - gsm - femto network , and the gan - wcdma - femto network all contain the ganc 13 . there are however some functional differences in how the ganc functions for example towards a gan - enabled ms and a hap utilizing the gan . the ganc may apply some security settings towards gan - clients . another exemplary difference is related to the cipher mode control procedure as described in 3gpp ts 48 . 008 and used in the context of the “ gan a / gb ”. the cipher mode control procedure enables the msc 21 to pass cipher mode information to the ganc 13 to select and load the user data and signaling encryption device with the appropriate key . however , in gan mode , all the communication between the ms 11 and the segw 14 is encrypted using the ipsec tunnel and there is no need for the encryption keys . this means that when the ganc receives the cipher mode command message , it only sends the algorithm to be used and a “ key index ” to the ms , which stores the information for possible future use after a handover to geran . the cipher mode command message also includes the encryption key , called kc , that is normally used by the bsc and bts to encrypt the air interface towards the ms . as described above , however , the ganc does not forward the kc key . there is a different need in the gan - gsm - femto network for the handling of the cipher mode control procedure . in this case , the ipsec tunnel is only used to encrypt the traffic between the ganc 13 and the hap 71 . the air interface between the ms 11 and the hap is a standard gsm air interface and this means that the “ kc ” information is needed in the hap to be able to cipher / decipher this air interface towards the ms . thus , the ganc 13 needs to know whether the gan registration and all associated traffic - related procedures relate to a gan - ms or to an ms accessing via the hap 71 . there is no known solution for informing the common node segw 14 about the different user types . one possible solution for informing the common node ganc 13 of the user types is to extend the gan classmark information that is included in the ga - rc register request message to indicate “ hap ” or “ ms behind hap ”. the ganc may then use this information to act differently towards the gan - ms or “ ms behind hap ” ( and towards the “ hap ” as well ). this approach , however , has several problems . first , the approach depends on the ms ( or gan - client ) accessing the system to set this information correctly . this is not acceptable because a faked gan - client could set the setting to lower the security restrictions applied and to receive sensitive information ( like the “ kc ” from the network ). secondly , this approach does not provide the user - type indication to the segw 14 . to solve the second problem , a protocol may be implemented between the ganc 13 and the segw 14 so that the ganc can inform the segw about the user type based on the information the ganc received from the client . however , this would also be a security risk in the case of a malicious client . furthermore , such an approach would mean that the client has already accessed the network without the segw knowing the user type . since the segw is the entry point to the mobile network and the first point of contact where the user &# 39 ; s identity is verified , security settings need to be applied from the segw . in the present invention , the network is configured with information about an association between an ( u ) sim and the user type . for this reason , the network does not have to rely on the client indicating a specific user type . the invention enables the segw 14 to retrieve information about different user types and to apply specific security functions based on the user type . thus , the invention is applicable to all solutions where a component such as the segw 14 is used . for example , the inventive concepts described herein are applicable , at least , for the following solutions : interworking wlan ( i - wlan ); in this case the segw is the packet data gateway ( pdg ). untrusted non - 3gpp ip access in sae / lte ; in this case the segw is the evolved packet data gateway ( epdg ). gsm - femto , wcdma - femto , and lte - femto ; uma / gan ; and combination of uma / gan and gsm / wcdma - femto . different embodiments of the present invention are used to illustrate how the segw 14 becomes aware of the user - type information , and how the ganc 13 becomes aware of this information . the segw may be informed utilizing an hlr - based configuration , an aaa - based configuration , or an segw - based configuration . the ganc may be informed by the segw after the segw learns the information through one of the configurations noted . alternatively , the ganc may be informed utilizing a ganc - based configuration or a gan database - based configuration . it should also be noted that the above embodiments may be combined in different ways . fig1 is a signaling diagram illustrating an existing method of performing ikev2 signaling and eap - sim / aka authentication in the gan solution . the authentication procedure of fig1 is reproduced from figure a . 1 of the technical specification 3gpp ts 43 . 318 v8 . 0 . 0 , and will not be discussed further except in the context of modifications and extensions associated with the different embodiments of the present invention described below . the description below presumes that the different “ user types ” are coordinated between the different nodes . for example , the segw 14 and the ganc 13 are aware of the different user types and have predefined logic that is dependent upon the user type . user types may include , for example , “ home access point ”, “ gsm hap ”, “ wcdma hap ”, “ lte hap ”, and the like . table 1 above provides an example of how the segw 14 may be configured for the different “ user types ”. these examples define limitations for each ipsec tunnel . for example , the exemplary table can be read so that user type “ gsm hap ” is allowed to use a bandwidth of 200kbits / second . the ‘ user type ’ itself provides certain information about how the nodes should act . other information per user type may be related , for example , to security settings . exemplary settings for the ganc 13 are shown in table 2 below . these examples define limitations for each gan registration in the ganc . for example , the exemplary table can be read so that user type “ gsm hap ” is allowed to send 200 messages per second . fig1 is a signaling diagram illustrating an extension of fig1 to implement the hlr - based configuration for informing the segw 14 of different user types . a new “ user type ” indication 91 is created in the hss / hlr 26 and returned to the aaa server 25 together with the security information in step 10 . the “ user type ” indication 91 may be based on an individual imsi or on an associated imsi number series . methods of creating the user - type indication other than variations of the imsi - number series are also possible . the aaa server then returns the “ user type ” information to the segw in step 17 and the segw utilizes this information to differentiate between different user types . fig1 is a signaling diagram illustrating an extension of fig1 to implement the aaa - based configuration for informing the segw 14 of different user types . in this embodiment , the new “ user type ” indication 91 is created in the aaa server 25 rather than the hlr / hss 26 . again , the user type indication may be based on an individual imsi or an associated imsi number series , although other methods of creating the user - type indication are also possible . the aaa server then returns the “ user type ” information to the segw in step 17 and the segw utilizes this information to differentiate between different user types . in the embodiment utilizing an segw - based configuration , the new “ user type ” indication 91 is created in the segw 14 and , again , may be based on an individual imsi or an imsi number series . the segw utilizes this information to differentiate between different user types . one drawback with this approach would be the required o & amp ; m . typically a number of ( distributed ) segws would exist , and all of them would need to be configured with user - type information associated with different imsis or imsi number series and kept updated . fig1 is a signaling diagram illustrating an embodiment of the present invention for providing user - type information to the ganc 13 . fig1 is a signaling diagram illustrating an extension of the gan registration procedure of fig3 to implement the embodiment in which the segw 14 provides the user - type information to the ganc . at step 93 , the segw obtains the user - type indication 91 through one of the embodiments above . at step 94 , the segw provides the user - type information to the ganc . the ganc then utilizes this information to differentiate between different user types . in another embodiment of the present invention , the new “ user type ” indication 91 is created in the ganc 13 and , again , may be based on an individual imsi or an imsi number series . the ganc utilizes this information to differentiate between different user types . one drawback with this approach would be the required o & amp ; m . typically a number of gancs would exist , and all of them would need to be configured with user - type information associated with different imsis or imsi number series and kept updated . in another embodiment of the present invention , the new “ user type ” indication is created in a gan database that is accessible from the ganc 13 . the ganc queries the gan database during the gan registration procedure of fig3 . again , the user - type information may be based on an individual imsi or an associated imsi number series . the ganc then utilizes this information to differentiate between different user types . although preferred embodiments of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description , it is understood that the invention is not limited to the embodiments disclosed , but is capable of numerous rearrangements , modifications , and substitutions without departing from the scope of the invention . for example , although the exemplary embodiments described herein utilized the gan - gsm - femto access network of fig7 and 8 , the invention may also be implemented utilizing the gan - wcdma - femto access network of fig9 and 10 . the specification contemplates any and all modifications that fall within the scope of the invention defined by the following claims .