Patent Publication Number: US-6993577-B2

Title: System and method for migration of subscriber data

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention is directed to automatically relocating private data in a communication network having a distributed architecture to increase the efficiency of the network and, more particularly, to moving subscriber records within that network based on pattern analysis of location data indicating when access to the information services requires retrieval of subscriber records from remote locations. 
   2. Description of the Related Art 
   There are many types of communication systems that have distributed architecture in which data that is frequently accessed is desirably located close to the initial port of access. For example, information about subscribers to cellular telephone systems is stored in a home location register (HLR) that must be accessed each time a call is made by or to a subscriber. Typically, the information is initially stored at the HLR closest to where the service is initiated or the residence or business address of the subscriber 
   When a cellular telephone is used outside the home area, the system controlling communication with the cellular phone accesses the HLR and stores the subscriber data in a visitor location register (VLR). The subscriber data in the VLR is used as long as the phone stays within the area service that is serviced by the VLR. The subscriber data in the VLR is removed if the phone is unused beyond a designated period of time. 
   Another example of a communication system with a distributed architecture is an enhanced services systems that provide messaging services to subscribers of telephone systems, both wireline and wireless systems. Such systems are examples of information services systems and may include facsimile servers, e-mail servers, unified messaging servers, providing financial services, news and sports reports, video on demand, music downloads, business information including addresses, telephone numbers, hours of operation, etc. Information services systems that are distributed over a wide geographic area, such as those that provide services to subscribers of a national or regional wireless telephone network, such as Sprint PCS®, AT&amp;T Wireless, Cegetel (France), T-Mobil (Germany), etc., allow their subscribers to access services through access ports that are distributed throughout the coverage area. The access ports store subscriber records that typically must be accessed to provide the services. To minimize use of network resources when the subscriber record is accessed, it is preferable to keep the subscriber record at the location that is closest to the access port first used by the subscriber. 
   Conventionally, subscriber records or profiles are relocated in response to notices received from a subscriber that the subscriber&#39;s primary location has moved, or by manual analysis of access to the services provided by the information services system. Known techniques for automatically relocating subscriber profiles and other private data associated with subscribers, e.g., messages stored for the subscriber, are only performed for purposes of load balancing, such as when a new server is installed, as disclosed in U.S. Pat. No. 5,909,483, incorporated herein by reference. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to improve efficiency of communication systems by automatically relocating subscriber records in a geographically distributed database. 
   Another object of the present invention is to reduce the use of network resources, such as transmission bandwidth, in accessing subscriber profiles and other private data in a geographically distributed database. 
   A further object of the present invention is to improve the quality of service to subscribers of information services systems. 
   The above objects are attained by providing a method of relocating data in a distributed communication system, including generating an activity log file of location data and identifiers, each identifier associated with one of a communication device and a person using the communication system; automatically performing pattern analysis based on the location data and the identifiers; and relocating private data, associated with one of the identifiers, from a first location to a second location within the communication system when the pattern analysis indicates that service can be provided more efficiently from the second location. 
   These objects, together with other objects and advantages which will be subsequently apparent, reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like reference numerals refer to like parts throughout. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a block diagram of a distributed information services system. 
       FIG. 2  is a block diagram of an information server in a distributed information services system. 
       FIG. 3  is a flowchart of a method according to the present invention. 
       FIG. 4  is a flowchart of pattern analysis and relocating subscribers&#39; private data. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   Although the present invention can be applied to many different types of communication systems, as an example an embodiment of the invention will be described in which the communication system is an information services, or enhanced services system having a distributed architecture. A block diagram of a portion of a distributed information services system  10  is illustrated in  FIG. 1 . Access to information services is provided by access units, specifically information servers  12 , four of which are illustrated in  FIG. 1 . An actual information services system could have 100 or more information servers  12 . The information servers  12  are interconnected by a data communication network  14 , such as a wide area network (WAN), and a public switched telephone network (PSTN) or public land mobile network (PLMN)  15  and sometimes to the Internet  16  via a firewall unit (FWU)  17  (see  FIG. 2 ). A management center  18  is also connected to the data communication network  14  to manage overall operation of the distributed information services system  10 . Typically, the information services system  10  is provided for subscribers of a single telecommunication network (e.g., a large regional or national cellular telephone network, such as Sprint PCS®). Under these circumstances, a host computer  20  of the telecommunication network company may be connected to the management center  18  to provide access to the operational information stored therein by the employees of the telecommunication network company. 
   An example of an information server  12  illustrated in  FIG. 2  is a TRILOGUE™ INfinity™ from Comverse Network Systems of Wakefield, Mass. However, it should be understood that the present invention is not limited to information servers having the architecture illustrated in  FIG. 2  and any suitable architecture may be used. Major components that may be included in an information server  12  include units providing basic messaging services  22 , such as voice mail and facsimile, unified messaging services, such as e-mail, and short message services. The short message service messages are conventionally communicated by cellular telephone network(s) in the PSTN/PLMN  15  or transmitted via a public data communications network, such as the Internet  16 . 
   The basic messaging services  22  are provided by a plurality of multi-media units (MMUs)  30 , connected to voice trunks in the PSTN/PLMN  15 , that perform voice signal processing functions and a plurality of messaging and storage units (MSUs)  32  that store the subscriber records and hosts application logic. The MMUs  30  can be provided by computers controlled by single or multiple microprocessors, such as Pentium-based computers, manufactured by Comverse Network Systems, Inc. of Wakefield, Mass., with 1 MB memory, 4 GB system disk storage, network interface cards and voice processing cards. The MSU  32  is similar computer having up to 18 GB additional storage for private subscriber information. A call control server (CCS)  34  interfaces with call signaling trunks, such as SS7, system message desk interface (SMDI), etc. in the PSTN/PLMN  15  to provide information on the calling number, etc. The CCS  34  may be a similar Pentium-based computer made by Ulticom Corp. of Mount Laurel, N.J. with network interface cards. Overall control of messaging services is performed by central management unit (CMU)  36  which is connected to the MMUs  30 , MSUs  32  and CCS  34  by high-speed backbone network (HSBN)  38 , such as a switched Ethernet supporting 10BaseT and 100BaseT. The CMU  36  may be an Alpha-based computer made by Compaq of Houston, Tex., with interfaces to the HSBN as well as to the host management computer of the network operator. 
   When a subscriber calls an information server, such as information server  12   a , the call reaches an MMU  30  that interacts with the subscriber record stored on the subscriber&#39;s home MSU  32 . The CMU  36  performs address resolution to identify the home MSU  32  and communicates with CMUs  36  in other information servers, e.g.  12   b ,  12   c  via routers  40  and data network  14  when the required home MSU  32  is located at one of the other information servers  12   b ,  12   c . If the subscriber&#39;s call reaches an MMU  30  with his home MSU  32  located on the same information server  12   a , that is local access. If the home MSU  32  is located on another information server  12   b  or  12   c , that is considered remote access. Remote access is less efficient, uses more network resources and potentially provides lower quality of service as compared to local access. 
   As illustrated in  FIG. 3 , the preferred embodiment relies upon information that is recorded  82  by the MSU  32  when a subscriber accesses the information services system  10  via one of the information servers  12 . Conventionally, information servers  12  such as the TRILOGUE® INfinity®, create activity logs that store information regarding voice mail, including all calls that create a message for subscribers, all calls by subscribers and outgoing calls to subscribers. In addition, the activity log tracks messages sent, transferred and replied to; message retrieval, receipt, duplication and deletion; etc. The activity log is used for billing purposes, statistical analysis, trouble shooting and other administrative functions. Similar logs of activity are typically kept by telephone and data communication equipment. Thus, it is expected that the call information required to implement the present invention is available in many types of access units and therefore the present invention is not limited to distributed information services systems utilizing the TRILOGUE® INfinity®. 
   To make use of the raw data accumulated in the activity log, the CMU  36  periodically collects  84  the data stored by each MSU  32  and stores the data in files for further processing. The processing may occur at individual information servers, such as when an information services system has only a single TRILOGUE® INfinity® or similar platform. In a distributed information services system  10  like that illustrated in  FIG. 1 , the collection  84  of data usually includes transmitting data from the information servers  12  to the management center  18  via data communication network  14 . The process of transmitting data from the information servers  12  to the management center  18  may use any conventional technique, such as polling by the management center  18  or pushing from the information servers  12 . 
   To implement the present invention, the data transmitted to the management center  18  (or analyzed by the information server  12 ) must include location data corresponding to subscriber calls and identifiers of the subscribers. The location data has two elements: the identity of the information server  12  on which the subscriber call has arrived and the identity of the information server  12  containing the home MSU  32 . In the preferred embodiment, the data is analyzed by the management center  18  and the location data need only specify which information server  12  sent the data to the management center  18 . It is also possible to perform the analysis described below in the information servers  12  in which case the location data is implicit in any data accumulated by the information server  12  in which the analysis is being performed. The subscriber identifier may be a voice mail box number, a telephone number of a mobile telephone, an email address, an IP address, etc. 
   After an activity log file containing the location data and identifiers has been generated, pattern analysis is performed  86  on the activity log file to determine which subscribers have accessed the distributed information services system  10  from a location remote from their home information server  12 . Optionally, there may be verification  88 , e.g., by human operators, of the subscribers selected for relocation. However, the present invention may be completely automatic with relocation  90  of private data occurring upon identification of a group or a single set of private data to be relocated. 
   A simplified example of pattern analysis is illustrated in  FIG. 4 . First, the collected call data is analyzed to detect  92  each time a subscriber has used an information server  12  whether the information server  12  has  94  the subscriber profile or other private data associated with the subscriber stored in its MSU  32 , or needs  96  to refer to private data stored by a different information server. This can be detected by comparing the location data for subscribers with a record of where the subscribers&#39; “home” information server  12  is located, by detecting messages sent between information servers  12  to send private data of subscribers from the home information server to the information server handling the call by the subscriber, or by similar techniques. After accumulating  94 ,  96  occurrences of subscribers accessing the distributed information services systems via home and non-home information servers for all of the data that has been collected, it is determined  98  whether a subscriber has more than a predefined number of access from a non-home information server. If so, the percentage of “non-home” accesses to “at-home” access is compared  100  with a predefined percentage. In the example illustrated in  FIG. 4 , the percentage is 75%, but the present invention is not limited to any particular percentage. 
   Other criteria may also be used to identify subscribers whose private data should be relocated. For example, the pattern analysis is preferably performed  86  periodically. If the period is as short as a week, the results of the pattern analysis may be accumulated before subscribers are moved, to avoid one- or two-week vacations, for example. Based upon a long term analysis of activity log files, it is possible to develop appropriate criteria for relocating subscribers. 
   The results of the pattern analysis are used to determine subscribers whose private data, such as subscriber profile data and optionally, messages, should be transferred from the current home information server to a new home information server. The subscriber data are preferably transferred at times that are determined to be “quiet” times for the information services system  10  so as not to create excessive load. This transfer may be performed automatically or under control of authorized employees of the telecommunications operator. 
   For example, as illustrated in  FIG. 4 , the identifiers of subscriber profiles may be batched  102  by current information servers. The identifiers for each batch are then sent  104  to the current information server storing the subscriber profiles for that batch. The current information server becomes an origination information server for the transfer  106  of subscriber profiles to at least one destination information server. The batches may be specific, such that all subscriber profiles in a batch go from the origination information server to a single destination information server, or may be routed to several destination information servers. In the preferred embodiment, the transfer  106  is coordinated by management center  18  which performs the analysis and sends the batches to the origination information servers. The management center  18  may also inform the destination information servers to prepare for receipt of the subscriber profiles, or this may be handled by communication directly between the origination information servers and the destination information servers. 
   Alternatively, the pattern analysis may be performed by each of the information servers  12 . For example, if non-home information servers always contact the home information server whenever handling an access by a “visiting” subscriber, the home information server can compare the number of such requests with the number of requests for access it has handled for the subscriber and determine when it is appropriate to transfer the subscriber to a different information server. Alternatively, subscriber profiles may be held by non-home information servers for “visiting” subscribers and after it is determined  98  that the number of accesses by the visiting subscriber exceeds the first threshold for a given period of time, the non-home information server could query the home information server (or the management system  18 ) to find out how many times that subscriber accessed its home information server directly and request the transfer of the subscriber profile if the second threshold is met  100 . If the analysis is performed by the information servers  12 , the subscriber profiles may be transferred with or without batching. 
   Many of the known techniques for transferring data within a distributed information processing system can be used to transfer the subscribers&#39; private data. Examples include the techniques disclosed in U.S. Pat. Nos. 5,627,877; 5,909,483; and 6,067,456, incorporated herein by reference. Most known techniques typically require some type of human identification of what private data should be transferred. As indicated above, this is unnecessary in the present invention. However, when the present invention is implemented in a voice mail system operated by a telephone company, the telephone company may desire to verify  88  the transfers before they occur. This can be accomplished by the connection between the communication network operator&#39;s host  20  and the management center  18 . 
   The many features and advantages of the present invention are apparent from the detailed specification, and thus it is intended by the appended claims to cover all such features and advantages of the system that fall within the true spirit and scope of the invention. Further, numerous modifications and changes will readily occur to those skilled in the art from the disclosure of this invention, thus it is not desired to limit the invention to the exact construction and operation illustrated and described. Accordingly, modifications and equivalents may be resorted to as falling within the scope and spirit of the invention.