Browse Prior Art Database

AUTO REDIAL SERVICE IN THE CT2 TWO WAY SYSTEM

IP.com Disclosure Number: IPCOM000007469D
Original Publication Date: 1995-Jul-01
Included in the Prior Art Database: 2002-Mar-28
Document File: 4 page(s) / 169K

Publishing Venue

Motorola

Related People

Ng See Woon: AUTHOR

Abstract

Figure 1 shows the System Architecture of the CT2 Two Way Calling System. Currently in the CT2 Two Way Calling System, when a handset makes an out-going call to subscriber "B" and if the called party is busy, the user will have to hang up and attempt the same call later if he is still interested in contacting the wanted party.

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MmROLA Technical Developments

AUTO REDIAL SERVICE IN THE CT2 TWO WAY SYSTEM

by Ng See Woon

ler born having to manually redial the numbers, if Auto Redial is not implemented in the TBS, and frees him to do other things.

PRIOR ART

Figure 1 shows the System Architecture of the CT2 Two Way Calling System.

  Currently in the CT2 Two Way Calling System, when a handset makes an out-going call to subscriber "B" and if the called party is busy, the user will have to hang up and attempt the same call later if he is still interested in contacting the wanted party.

  The PSTN offers a service called Auto Redial which can be activated by pressing an encapsulation of the called number in a fixed key sequence, e.g. #560(phone number)#. If the number is free, the call will get through, in which case Auto Redial is not activated. If the number is engaged, a repeated tone indicating the wanted party is engaged can be heard and the call will be placed on Auto Redial. The exchange will make three attempts randomly within 10 minutes to try and reach the wanted party. When the connection is established, both phones will ring.

  This service though available, cannot be used in the CT2 Two Way Calling System. Unlike a normal telephone, the ISDN lines connected to the Telepoint Base Stations are not associated with any handsets. When a handset gets a link with the Base Station and makes a call, whatever BRI available is used for the call; there is no association of BRI to handset whatsoever. This renders subscription to Auto Redial service for the BRI not practical.

  To offer the service ofAuto Redial to CT2 hand- set users, the implementation of the service has to be in the Base Station. Like the service offered by the PSTN, the Base Station will automatically try to make the connection to the busy number for a predetermined number of times (e.g. 5 attempts spaced at 2 minute intervals). This relieves the cal-

  During the out-going call to a busy number, the PID originating the out-going call is stored in a AUTO-REDIAL table together with the busy called number. When this AUTO-REDIAL table is not empty, a 2 minute timer is set running, and upon time out, the PIDs in the AUTO-REDIAL table are polled to see ifthey are still in range (with- out alerting the handset) and not currently tied up on another link with the Base Station. For these handsets, attempts will be made to reach the corresponding busy numbers. If the connection is established, the Base Station will begin to poll the handset (with alerting signals) and transmits the called number to the handset at the same time. When either party picks up the call, they will hear the ring- ing tone until the other party connects. At that point, conversation between the two parties can proceed.

  If the called party is busy, retries are made at mrther 2...