Abstract:
A wireless communication system includes a base station that receives information regarding neighboring wireless systems and updates and stores this information for use in handover of user equipments (UEs).

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. patent application Ser. No. 11/405,088, filed on Apr. 17, 2006, which is a continuation of U.S. patent application Ser. No. 10/822,502, filed on Apr. 12, 2004, which issued as U.S. Pat. No. 7,058,405, which is a continuation of U.S. patent application Ser. No. 10/328,623, and filed Dec. 23, 2002, which issued as U.S. Pat. No. 6,735,443, which claims priority from U.S. Provisional Application No. 60/392,211 filed on Jun. 28, 2002, all of which are incorporated by reference as if fully set forth. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to wireless communication systems. In particular, the invention relates to database processing of information for user equipment (UE) handover. 
       BACKGROUND 
       [0003]    User equipment (UE) in wireless communication systems are beginning to provide functionality for internet/public service telephone network (PSTN) access via multiple wireless systems (such as (WLANs), Bluetooth® a registered trademark for a wireless network, universal mobile telecommunications system (UMTS), general packet radio service (GPRS), etc.). Hence, there is a growing need for these systems to work with each other in order for a UE to handover from one technology to another. 
         [0004]    To assist in a handover, a wireless communication system base station can relay to a UE the information pertaining to outside systems. Thus, a base station needs to retain and constantly update information about the other systems. Retrieval of the information about another system is possible through secure inter-system connections (such as via an IP-cloud, for example) under roaming agreements. However, it is a deployment challenge to maintain and update such information about other systems. Hence there is a need for an alternate source to assist the base station in supplying the outside system information in order to eliminate the need for explicit inter-system connections and communications for this purpose. 
       SUMMARY 
       [0005]    The present invention employs a technique for obtaining and updating data relating to neighboring wireless systems. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES  
         [0006]      FIG. 1  is a simplified diagram showing a plurality of wireless systems and user equipments within the wireless systems, which may employ the technique and principles of the present invention to great advantage. 
           [0007]      FIG. 2  is a flow diagram useful in explaining the principles of the present invention and a method to implement such a system. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0008]      FIG. 1  shows a multimode UE  101  operating within a wireless system  102  having an associated base station (BS)  102   b,  while also being able to detect multiple surrounding wireless systems  103 - 105 . Upon detection of information from wireless systems  103 - 105 , UE  101  sends the current information to BS  102   b  of system or systems  103 - 105 . BS  102   b  can then update its database based on this new information from UE  101 . Likewise, subsequent handovers of UE  101  to other base stations can provide base station database updates. For example, after handover to wireless system  103 , UE  101  sends information pertaining to the most recently resident system (i.e., system  102 ), to base station (BS)  103   b,  which then updates its database accordingly. 
         [0009]      FIG. 2  shows a process flow diagram for the exchange of information between BS  102   b  and UE  101 . Although this process is shown with a single UE for simplicity in explanation, multiple UEs may interact with BS  102   b  at the same time. System information that is sent from a UE to the BS and vice versa may include, but is not limited to: geo-location of a UE, new system, congestion at the network and failure to detect a network. 
         [0010]    At UE-S 1 , UE  101  obtains information relating to network  104 , for example. At step UE-S 2 , UE  101  transmits its identity to BS  102   b.  At step BS-S 1 , BS  102   b  receives the identity of UE  101 . At BS-S 2  BS  102  first authenticates the identity of UE  101 . This ensures that BS  102   b  will not accept information about other systems from malicious UEs. Next, at step UE-S 2 , responsive to the authentication, the information is protectively encoded for integrity by UE  101  and, at step UE-S 3 , the protected information is transmitted by UE  101  to BS  102   b.  A preferred method of protective encoding is via message authentication codes. Encryption may also be used to protect the information from being eavesdropped. At step BS-S 3 , BS  102   b  verifies the integrity of the information. At step BS-S 4 , BS  102   b  accepts the information and updates its databases. Now that BS  102   b  has updated its database, BS  102   b,  at step BS-S 5 , may communicate with adjacent systems  103 - 105  at regular intervals or triggered instants of time to validate the information updates received from UE  101 . Corrections to the database, if needed are made at step BS-S 6 . 
         [0011]    System efficiency can be gained by BS  102   b  taking a proactive role in letting UE  101  know of its surrounding systems, at step BS-S 7 . Hence, UE  101  need not send any information if its resident system is on the list provided by BS  102   b.  This reduces radio traffic due to multiple UEs sending similar information. 
         [0012]    This database stored in each BS is used for cell re-planning and system layover during deployment of additional networks. For example, consider a UMTS system overlaid over disjointed WLANs. The information gathered at the UMTS base station is used for planning WLAN network in that area. System  102  gets geo-locations of different UEs as they communicate about other systems (say System  103 ). The operator can use the geo-location of each UE that reported about system  103  to approximate the coverage of system  103 . This approximate coverage area can be used to plug coverage holes or future deployment planning of system  103 .