Browse Prior Art Database

REDUCING PROCESSOR WORKLOAD USING SUBSCRIBER BEHAVIOR PROFILES

IP.com Disclosure Number: IPCOM000006283D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-20
Document File: 3 page(s) / 187K

Publishing Venue

Motorola

Related People

Patrick L. Reilly: AUTHOR

Abstract

In the GSM cellular architecture, authentication sets must be generated by the Home Location Register (HLR) for each subscriber, usually as a vector of 5 sets. The vector, or the authentication set pool, is then stored within the Visited Location Register (VLR) for use by the mobile subscriber.

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MOTOROLA INC. Technical Developments Volume 14 December 1991

REDUCING PROCESSOR WORKLOAD USING SUBSCRIBER BEHAVIOR PROFILES

by Patrick L. Reilly

THE PROBLEM

  In the GSM cellular architecture, authentication sets must be generated by the Home Location Register (HLR) for each subscriber, usually as a vector of 5 sets. The vector, or the authentication set pool, is then stored within the Visited Location Register (VLR) for use by the mobile subscriber.

  When the subscriber exhausts the sets within a vector, the VLR must request new authentication vectors be generated by the HLR. Such a practice, con- ducted in real time, presupposes high speed processing capability and nominal signalling t&Cc loads on the links connecting the HLR and VLRs. Unfortunately, such assumptions are not valid in reality, as will be demonstrated.

  Instead, the subscriber authentication vectors can be pre-calculated by the HLR during off-peak hours and stored for subsequent use by the subscriber during the normal business day. Furthermore, any real-time activ- ity that might reduce the subscriber's authentication set pool can be monitored and the pool adjusted based upon the subscriber's statistical behavior. In the usual situa- tion, the actual number of subscriber vectors to be gen- erated follows a bruteforceapproach:

Determine total number of subscribers in database and the total call attempts made during a typical business day. Determine average number of authen- tication sets needed by a subscriber:

sets needed = [total calls * (call attempts/sub + mobility mgmt. events per call)]/total subscribers

  Assuming an average of X bytes per authentication set, X bytes/set* total sets/subscr, day, would have to be stored in a database. The brute force method makes no provision for unique subscriber behavior in an attempt to optimize the storage space and/or any real-time processing required to generate daily subscriber authentication vectors.

e Motorola. I"C~ 1991

THE SOLUTION

  Unlike the brureforceapproach described before, this solution uses dynamic subscriber patterns of behavior to reduce the real-time processing times and database storage requirements for authentication vectors, while still providing the customary levels of network perform- ance. During the business day the number of authenti- cations actually used by the subscriber will be monitored as they are being drawh from the subscriber's authenti- cation set pool.

  There is essentially one situation that will spawn a real-time request for authentication sets during the busi- ness day. Each hour the subscriber's call attempts and mobility activity will require the VLR to draw authenti- cation sets from the subscriber's authentication pool. If at any time the number of authentication sets remaining in that pool are below some threshold, the VLR will request the HLR to generate a fresh supply of authenti- cation sets immediately, i.e., in real-time. Unfortunately, these real-time requests require the HLR...