Patent Publication Number: US-9854497-B2

Title: Method and apparatus for self configuration of LTE e-Node Bs

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. application Ser. No. 15/068,991, filed on Mar. 14, 2016, which is a continuation of U.S. application Ser. No. 14/601,332, filed on Jan. 21, 2015, now U.S. Pat. No. 9,320,066, which is a continuation of U.S. application Ser. No. 11/875,693, filed on Oct. 19, 2007, now U.S. Pat. No. 8,977,839, which claims the benefit of U.S. provisional Application No. 60/862,341, filed on Oct. 20, 2006, the contents of each are incorporated by reference herein as if fully set forth. 
    
    
     FIELD OF INVENTION 
     The present invention relates to wireless communication systems. 
     BACKGROUND 
     The Third Generation Partnership Project (3GPP) has initiated the Long Term Evolution (LTE) program to bring new technology, new network architecture, new configurations, and new applications and services to wireless cellular networks in order to provide improved spectral efficiency and faster user experiences. LTE also requires a low maintenance system in terms of network deployment and runtime service optimization. This is the background for the current LTE evolved universal terrestrial radio access network (E-UTRAN) Self Configuration and Self Optimization work effort. 
     Prior to LTE, the UTRAN architecture of the currently used 3GPP universal mobile telecommunications system (UMTS) is shown in  FIG. 1 . The radio access network or radio network system (RNS) or the UTRAN  10  comprises one or more radio network controllers (RNC)  11  and one or more Node-Bs  12 . The configurations and operations of deployed Node-Bs  12  currently are totally controlled by RNC  11  using explicit commands over Iub link  13 . Any configurations and service upgrades of Node-Bs  12  depend on RNC  11  and other cell engineering and planning efforts. Currently, there is no ability or requirements that exist for self configuration and optimization of Node Bs by the Node B. 
     Accordingly, a method and apparatus for self configuring LTE evolved Node-Bs (eNBs) are desired. 
     SUMMARY 
     A method and apparatus are disclosed for a self configuring eNB/UTRAN. The eNB/E-UTRAN interacts with the Evolved Packet Core (EPC) of the Long Term Evolution (LTE) network in order to complete the mutual authentication task between the eNB and the EPC, and other operating procedures in the eNB self configuration phase. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a block diagram of the current 3GPP UTRAN architecture; 
         FIG. 2  is a block diagram of an example Long Term Evolution (LTE) E-UTRAN network sharing architecture; 
         FIG. 3  is a block diagram of an example eNB; 
         FIG. 4  is an example signal diagram for primary operator serving access gateway (aGW) resolution and IP address acquisition; 
         FIG. 5  is an example block diagram of a Serving aGW in a non-primary operator&#39;s network; 
         FIG. 6  is an example diagram for eNB authentication with an aGW and Authentication Center (AuC); 
         FIG. 7  is an example signal diagram for eNB-location-Id for calculating XRES/RES; and 
         FIG. 8  is an example signal diagram for E-UTRAN Parameter Request. 
     
    
    
     DETAILED DESCRIPTION 
     Hereafter, a wireless transmit/receive unit (WTRU) includes but is not limited to a user equipment, mobile station, fixed or mobile subscriber unit, pager, or any other type of device capable of operating in a wireless environment. When referred to hereafter, a base station includes but is not limited to a Node-B, site controller, access point or any other type of interfacing device in a wireless environment. 
     An eNB is disclosed that is linked directly with the EPC and among other eNBs and performs the radio access network functionality for E-UTRAN. An example LTE system  20  including the disclosed self configuring eNB is illustrated in  FIG. 2 . LTE system  20  comprises an EPC network  80  and a radio access network (RAN) operator  100 . RAN operator  100  comprises one or more eNBs  30  (i.e.,  30   a ,  30   b  and  30   c.    
       FIG. 3  is an example of a functional block diagram of an eNB  30 . In addition to components included in a typical transceiver, eNB  30  includes a processor  125 , configured to perform self configuration, as disclosed below. The eNB further includes a receiver  126  in communication with the processor  125 , a transmitter  127  in communication with the processor  125 , and an antenna  128  in communication with the receiver  126  and the transmitter  127  to facilitate the transmission and reception of wireless data. 
     Referring back to  FIG. 2 , EPC  60  coupled to the one or more eNBs  30  through S1 link  40 , comprises one or more mobility management entities/User Plane Entities (MME UPEs)  50  and an access gateway (aGW)  70 . As those having skill in the art know, S1 link  40  provides support for load sharing of traffic across network elements in EPC  60 , MME UPEs  50  and aGWs  70 , by creating pools of MME UPEs  50  and aGWs  70  and allowing each eNB  30  to be connected to multiple MME UPEs  50  and aGWs  70  in a pool. MME UPE  50 , coupled to aGW  70 , assists EPC  60  in choosing a serving aGW for eNB  30 . Also coupled to MME UPE  50  is eNB  30  through S1 link  40 . 
     In accordance with the present teaching, eNBs  30  assume the radio access network (RAN) configuration, operation and management control functions as well as the radio interface configurations and operations. The eNBs further interact directly with EPC  60 , as well as, with neighboring eNBs  30  or other network nodes to directly handle WTRU Mobility management tasks. 
     Disclosed self configuring eNB  30  is coupled to one or more aGWs  70  and MME UPEs  50  belonging to different network operator/service providers  80 , either physically or logically. In the disclosed method, self configuring eNB  30  performs eNB authentication through the primary operator&#39;s serving aGW interface. 
     Primary network operators  80 , Operator  80   a  and  80   b  for example, may include more than one aGWs  70   a ,  70   b  (e.g.,  70   a   1  and  70   a   2 ,  70   b   1  and  70   b   2 , respectively) from an aGW pool currently connecting to eNB  30 . Each individual aGW  70   a ,  70   b  could potentially serve as the serving aGW for eNB  30 . It is the primary operator&#39;s responsibility for assigning one of the aGW to act as the serving aGW (towards this eNB) for the eNB upon initial configuration to the EPC  60 . eNB  30  is then able to interact with the designated serving aGW in the primary operator&#39;s network  80 , and through which eNB  30  performs the eNB authentication and E-UTRAN operating parameter acquisition. 
     For purposes of this disclosure, a primary operator is defined as the network operator or service provider that deploys the eNB in concert with the Public Land Mobile Network Id (PLMN-Id). A serving aGW is defined as the aGW that currently bridges to the network designated entity (such as an O&amp;M or an authentication center (AuC), not shown) and interacts over S1 C-plane of S1 links  40  with the eNB  30  for a specific task, such as eNB self configuration. 
     Preferably, eNB  30  belongs to the primary (deploying) operator, Operator A  80   a  in the example illustrated in  FIG. 2 , and therefore is self configured by its own operator, thereby serving not only the standardized functionalities to the LTE networks, (primary or non-primary operator&#39;s networks), but also the deploying operator&#39;s specific features or functionalities. 
     As such, the eNB authentication and E-UTRAN operating parameter acquisition in the eNB self configuration phase are conducted with the primary operator&#39;s serving aGW. The acquisition and authentication is performed only once with each eNB  30  power up session. The result of the actions with the primary operator network  80  shall enable eNB  30  to obtain information and policies regarding how to interact with the rest of non-primary operator&#39;s networks  80   b.    
     Given the multiplicity of S1 links  40  to an eNB  30 , a port/address/interface identity is used by eNB  30  to start the eNB authentication and E-UTRAN parameter acquisition. If the multiplicity is realized physically, (i.e. there are as many physical links/wires connecting to the eNB), each S1 link  40  ending at a different aGW  70 , a primary S1 link port, physically connecting the port to the primary operator&#39;s network  80  (may also be the primary operator&#39;s serving aGW for the eNB) may be used in one disclosed method of eNB authentication. The advantage of this architecture is that it avoids the overhead required when running a node resolution procedure, to be disclosed below. However, this architecture requires the installation be primary-operator-serving-aGW sensitive. 
     If the IP address (or a fully qualified domain name or URL) of the primary operator&#39;s serving aGW (for initialization) is pre-configured to the eNB (maybe together with all other aGWs), then in another disclosed method of eNB authentication self configuring eNB  30  may rely on the underlying IP network to connect the serving aGW given only the destination IP address. 
     In yet another method of authentication, the eNB parameters may be pre-configured and stored in an universal integrated circuit card (UICC) device, for example, for easy retrieval and update. 
     In a preferred method of eNB authentication, the multiple S1 links  40  are logically distinctive. As such, a node resolution method is preferably used to aid self configuring eNB  30  in identifying the primary operator&#39;s  80   a  serving aGW and to obtain necessary information regarding the connected aGWs  70 . 
     Upon power up and initialization, an upcoming eNB  30  reads the UICC device for its pre-configured identities, such as the eNB-Id and its deploying operator&#39;s identity, the public land mobile network (PLMN)-Id, as well as, certain of its security parameters such as the shared-secret-key among eNBs  30   a  and aGWs  70  for initial serving aGW resolution. The key shall be configured to eNB  30   a  with a UICC device or other secure methods. It is preferable that a self protecting UICC provide access with the required identity to operate and also be able to destroy or conceal all data and functions upon illegal access, such as pulling out of the card slot without proper release steps. 
       FIG. 4  illustrates an example signal diagram of a disclosed eNB method for primary operator serving aGW resolution and IP address requisition. Once eNB  30  has obtained its eNB-ID, PLMN-ID and the like, self configuring eNB  30  broadcasts to all connecting aGW interfaces, or sends to each aGW,  70   a   1 ,  70   a   2 , (Primary Operator  80   a )  70   b   1 ,  70   b   2 , (Non-primary Operator  80   b ) a “Serving aGW Resolution Request” message  400  with encoded (encoding with a shared-secret-key to prevent general identity steal by wire mapping) eNB-Id and PLMN-Id, for example. Other eNB credentials may also be used for encoding the request, including a request type (Req_Type) of one from &lt;Initial deployment, eNB restart, eNB relocation&gt; to identify the respective eNB self configuration scenarios. 
     Alternatively, an eNB location identity (generated by fresh global positioning system (GPS) measurement of longitude, latitude, and/or altitude and converted to a single eNB-location-Id and normalized) may also be included in the “Serving aGW Resolution Request” message to disclose the geographical location of eNB  30  at initial deployment or at eNB relocation to prevent the possible fraud of eNB impersonation. 
     Each aGW  70   a   1 ,  70   a   2 ,  70   b   1 ,  70   b   2  that receives the serving aGW Resolution Request then checks to see if the PLMN-Id matches its own PLMN-Id to determine whether it is eNB&#39;s  30   a  primary operator. aGW(s) ( 70   a   1 ,  70   a   2  in this example) with matching PLMN-Id will further check the eNB-Id to determine if it is the serving aGW (among many in the aGW pool) for requesting eNB  30   a  (up to the service distribution and assignment of the primary operator). The serving aGW will then gather operational information for the eNB. In the example illustrated in  FIG. 2 , the serving aGW is designated  70   a  for eNB  30   a.    
     Serving aGW  70   a  then replies to eNB  30   a  using a “Serving aGW Resolution Response” signal  403  with the field serving−aGW=TRUE. The reply may also include other identities and other parameters for subsequent procedures and operations. 
     In an alternative method, all other non-primary operators  80   b  and non-serving aGWs  70   b   1 ,  70   b   2  may also learn about the upcoming eNB  30   a  and reply with a serving aGW Resolution Response  402  with a field serving−aGW=FALSE and its identities such as the aGW-Id and the PLMN-Id, and the like. 
     As self configuring eNB  30   a  has received serving aGW&#39;s  70   a   1  positive response and its IP address derived, eNB  30   a  then activates the IPsec security setup with a Security Association and “Internet Key Exchange Protocol” procedures to the underlying IP layer to enable the secure link between eNB  30   a  and the serving aGW  70 . 
     Alternatively, via pre-arrangement, an aGW  70   b   1 ,  70   b   2  in non-primary operator network  80   b  may also respond to the “Serving aGW Resolution Request” from eNB  30   a  with a positive response (i.e. serving−aGW=TRUE). If there is not an aGW in the primary operator&#39;s network  80   a  responding with a claim of being the serving aGW, then self configuring eNB  30   a  may take the response of non-primary operator aGWs  70   b   1 ,  70   b   2  seriously and consider responding aGW  70   b   1  or  70   b   2  as the serving aGW for pursuing all subsequently described actions. As illustrated in  FIG. 5 , in accordance with this alternative method, eNB  30  serving a GW  70   b   1 , would pursue authentication and E-UTRAN operating parameter acquisition, for example. 
     To LTE system  20 , authentication of a new eNB  30   a , or a restarting eNB, is a necessary network security procedure. As those having skill in the art know, security threats to an eNB are not as great as those to a WTRU generally for the following reasons:
         the wired configuration provides point to point communication, which is much more difficult to perform free listening, tracking, security key and ciphering break. Therefore, the challenge and response authentication protocol used for a WTRU authentication shall be sufficient for eNB authentication;   unlike WTRUs, the geographical location of an eNB is generally fixed, and if it is detected as changed (except the first deploying moment or subsequent scheduled eNB relocation), it may be a sign of trouble (a security fraud usually is not committed at the same place in a visible open location of an eNB), a property that may be used as a security parameter; and   since the S1 link  40  interface is protected by the underlying IPsec, no specific security keys/ciphering agreement are needed over the S1 link at the application protocol level, and as a result, no LTE specific security key agreement is needed during the eNB-network authentication.       

     Given the above, a method for authenticating self configuring eNB  30   a  is disclosed. An example signal diagram of this disclosed method is illustrated in  FIG. 6 . AS disclosed above, eNB  30   a  establishes its service aGW through the sending of the serving aGW resolution request, which may include a Req_type, eNB-ID, PLMN-Id and/or a eNB-location-Id, and receiving from serving aGW  70   a   1  a serving aGW resolution response. eNB authentication is then initiated from serving aGW  70   a   1  at the triggering of any of the following:
         a new eNB self configuring or a eNB relocation start with a serving aGW request providing the eNB-location-Id (generated from the GPS on these two occasions); or   a restarting eNB or a relocating eNB transmitting a Serving aGW Resolution request.
 
Serving aGW  70   a   1  then sends an eNB Auth Data request  601  to the authentication center (AuC)  610  including eNB  30   a  identities, e.g., eNB-Id and eNB Location-Id. AuC  610  then generates the authentication parameters and sends them to serving aGW  70   a   1 , which are included in an E-NB Auth. Data Response signal  602 . Serving aGW  70   a   1  starts the authentication with self configuring eNB  30   a  by forwarding an E-NB Auth Request signal  603 , which includes a Random number (RAND).
       

     eNB  30   a  then computes an expected medium access control (MAC) (XMAC) and a Response (RES), checks the computed XMAC against a MAC, and sends the computed RES included in an E-NB Auth Response signal  604  to Serving aGW  70   a   1 . Serving aGW  70   a   1  checks the RES and sends an authentication complete signal, e-NB Auth Complete  606 , to eNB  30   a  and AuC  610  if RES is correct. Successful authentication completes with the authentication complete message. Authentication preferably fails if either one of the two checks fails, i.e., MAC or RES. 
     An alternative method of authenticating eNB  30   a  is disclosed, wherein an eNB location, preferably generated by a GPS location, may be included as a factor in the authentication calculation (RES against XRES) resulting in tighter network authentication against eNB  30   a .  FIG. 7  illustrates an example signal diagram of the disclosed authentication method using an eNB location Id. 
     Referring to  FIG. 7 , the disclosed method may be triggered by eNB  30   a  requesting to change its serving aGW, for example. Upon receipt of such a request, serving aGW  70   a   1  forwards an E-NB Auth Data Request  700 , which includes the eNB location-Id measured by eNB  30   a  and the eNB-ID, to AuC  610 . AuC  610  then generates a sequence number (SQN) and a random number (RAND). An authentication management field (AMF) is then determined, and a MAC and RES encoded. In accordance with the teachings of this method, the XRES generated by AuC  610  via shared secret key K and the random number RAND running f2 algorithm, as known to those having skill in the art, may either be encoded by the RAND or by the normalized eNB-location-Id. The decision to use the RAND or eNB-location-Id is preferably dependant on the value of AMF, which is used to convey the authentication protocol information. 
     A trigger for employing the eNB-location-Id for XRES/RES may originate from serving aGW  70   a   1  on special occasions, such as the serving aGW relocation, eNB initial deployment, restart or eNB relocation, or detection/report of unusual activities at the concerned eNB. 
     AuC  610  encodes the AMF for the XRES generation, using RAND, or using eNB-location-Id, in accordance with this method, and forwarded serving aGW  70   a   1  in an eNB Auth Data Response  701 . The AMF value, included in an E-NB Auth Request signal  702 , is then sent to eNB  30   a  for decoding the XMAC as well as for determining whether to use RAND or use eNB-location-Id for computing the RES value. Employing the eNB-location-Id (which is not transferred at the authentication request to eNB) in the XRES computation makes an attempt to impersonate an eNB very difficult. 
     Referring to  FIG. 7 , it should noted that the f1*, f2* and f5* functional blocks indicate the current f1, f2 and f5 algorithm functions used in UMTS can still be used for the same purpose. Alternatively, other security algorithms with the same inputs and outputs can also be used to calculate the (X)MAC, (X)RES and AK. 
     The disclosed self configuring eNB  30  retrieves operating parameters for the E-UTRAN in order to attach to, interact, and operate with E-UTRAN elements, for example. Other network operators  80   b  (and their aGWs  70   b   1 ,  70   b   2 ). When self configuring eNB  30   a  has successfully authenticated with the primary operator&#39;s network  80   a  (when it receives the authentication complete message), eNB  30   a  may request the other network operator&#39;s  80   b  operating parameters from serving aGW  70   a   1 . These include parameters for operating with non-serving aGWs  70   b   1 ,  70   b   2  (MME and their UPEs) as well as various neighboring eNBs  30   b ,  30   c  LTE or non-LTE.  FIG. 8  is an example signal diagram of a disclosed method for a self configuring eNB to retrieve the operating parameters. 
     Referring to  FIG. 8 , self configuring eNB  30   a  sends an E-UTRAN Parameter Request  800  to serving aGW  70   a   1  including the identities of the respective EPC/aGW and the identities of the eNB-Ids, for whom the interacting policies, and operating parameters are requested. Serving aGW  70   a   1  responds by sending an E-UTRAN Parameter Response signal  801  including the operating parameters for the respective aGWs and eNBs requested. Example categories of operating parameters may include the following:
         For the primary operator aGWs:
           U-plane traffic handling parameters;   CN-NAS specific information; and   LCS and MBMS operation information;   
           For Non-primary operator&#39;s aGWs
           Policies towards the non-primary aGWs such as charging policy, security settings, handover policies and settings;   U-plane traffic handling behaviors, routing priorities, throughput limit, handover behaviors; and   CN-NAS specific information towards that specific PLMN;   
           Neighboring eNB/Cell Information
           Information on the association among networks (PLMN-Id), tracking area (TA-Id) and neighboring cells (Cell-Id);   UE security parameters;   Neighboring cells policies such as base stations could have handover with (LTE eNBs with X2 links and 2G/3G cells whose SGSN has a S3 connection with a connecting aGW), base stations could only do cell reselection with, and the like; and   Cell operating frequency and cell bandwidth requirement, other RF related parameters, power parameters such as limits and thresholds, and the like.   
               

     Although the features and elements of the present invention are described in particular combinations, each feature or element can be used alone without the other features and elements or in various combinations with or without other features and elements. The methods or flow charts provided may be implemented in a computer program, software, or firmware tangibly embodied in a computer-readable storage medium for execution by a general purpose computer or a processor. Examples of computer-readable storage mediums include a read only memory (ROM), a random access memory (RAM), a register, cache memory, semiconductor memory devices, magnetic media such as internal hard disks and removable disks, magneto-optical media, and optical media such as CD-ROM disks, and digital versatile disks (DVDs). 
     Suitable processors include, by way of example, a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs) circuits, any other type of integrated circuit (IC), and/or a state machine. 
     A processor in association with software may be used to implement a radio frequency transceiver for use in a wireless transmit receive unit (WTRU), user equipment (UE), terminal, base station, radio network controller (RNC), or any host computer. The WTRU may be used in conjunction with modules, implemented in hardware and/or software, such as a camera, a video camera module, a videophone, a speakerphone, a vibration device, a speaker, a microphone, a television transceiver, a hands free headset, a keyboard, a Bluetooth® module, a frequency modulated (FM) radio unit, a liquid crystal display (LCD) display unit, an organic light-emitting diode (OLED) display unit, a digital music player, a media player, a video game player module, an Internet browser, and/or any wireless local area network (WLAN) module.