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 
     This application is a continuation of U.S. patent application Ser. No. 10/822,502, filed on Apr. 12, 2004 and Ser. No. 10/328,623, filed Dec. 23, 2002, which claims the benefit of U.S. provisional application No. 60/392,211 filed on Jun. 28, 2002, which is incorporated by reference as if fully set forth. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to wireless communication systems. In particular, the invention relates to database processing of information for user equipment (UE) handover. 
     BACKGROUND 
     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. 
     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 
     The present invention employs a technique for obtaining and updating data relating to neighboring wireless systems. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         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. 
         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 
       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. 
       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. 
     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 . 
     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. 
     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 .