Browse Prior Art Database

REMOTE SITE CALL REQUEST QUEUEING DURING CONTROLLER OVERLOAD

IP.com Disclosure Number: IPCOM000008459D
Original Publication Date: 1997-Dec-01
Included in the Prior Art Database: 2002-Jun-17
Document File: 2 page(s) / 92K

Publishing Venue

Motorola

Related People

Jerald M. Gard: AUTHOR

Abstract

SmartZone and Omnilink are wide area, multisite, wireless communications systems. These systems are designed such that centralized computers, which will be referred to as Zone Controllers, perform the critical operations required to establish communica- tions in the wireless network. At times the Zone Controller can become overloaded due to unusually high network trafftc or due to a network interrup- tion. If no action is taken to counteract the overload condition, the Zone Controller may not be able to continue to process calls correctly.

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MO-LA Technical Developments

REMOTE SITE CALL REQUEST QUEUEING DURING CONTROLLER OVERLOAD

by Jerald M. Gard

BACKGROUND AND PROBLEM

  SmartZone and Omnilink are wide area, multisite, wireless communications systems. These systems are designed such that centralized computers, which will be referred to as Zone Controllers, perform the critical operations required to establish communica- tions in the wireless network. At times the Zone Controller can become overloaded due to unusually high network trafftc or due to a network interrup- tion. If no action is taken to counteract the overload condition, the Zone Controller may not be able to continue to process calls correctly.

  There are existing methods that can be used to "ride through" the overload condition, however, these methods are insufficient and could further exacerbate the overload condition. Once the over- load condition is detected, the Zone Controller can simply start dumping subsequent call requests. This action causes the subscriber units to retry their call requests for an amount of time. The retries will in turn put even more load on the Zone Controller, since the Zone Controller will have to process each retried request.

  Another option the system has is to inform the subscriber units to not issue any more call requests. This is generally accomplished by the system issu- ing a status word on the outbound control channel which indicates that the system is temporarily not accepting any more service requests. This solution works tine until the infrastructure attempts to return to its normal operating mode. When the status word is updated to indicate that service requests are again allowed, there could potentially be many subscriber units waiting to transmit a service request on the

inbound control channel. All of these subscriber units are going to try to send in th...