The Prior Art Database and Publishing service will be updated on Sunday, February 25th, from 1-3pm ET. You may experience brief service interruptions during that time.
Browse Prior Art Database

Automatic SMS Generation Service

IP.com Disclosure Number: IPCOM000011040D
Original Publication Date: 2003-Feb-11
Included in the Prior Art Database: 2003-Feb-11
Document File: 2 page(s) / 28K

Publishing Venue


Related People

Salomon Serfaty: AUTHOR [+3]


A way of disabling some or all of the functionality of a subscriber in a given environment is proposed.

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 50% of the total text.

Automatic SMS Generation Service

by Salomon Serfaty, Joseph Ziv and Rafi Carmon


A way of disabling some or all of the functionality of a subscriber in a given environment is proposed.


Problem To Be Solved

In some public areas such as concert halls, restaurants, hospitals, etc. the use of wireless communication devices, especially those supporting dispatch, high volume calls, is annoying to surrounding people and/or undesirable.

We propose here a way of disabling some or all of the functionality of a subscriber in a given environment using some of the features of the communication protocol and/or modification to it with the corresponding software support in the subscriber.

There have been suggestions to interfere with the control channel of the system so as to make it unavailable in certain areas by transmitting a continuous signal at the control channel frequency in the confined areas. This method totally disables the communication system.

Proposed Solution to the Problem

We propose to use, in such confined areas, a subscriber that is able to listen to the control channel of the system in the coverage area and capable to transmit at the same frequency as the control channel. This can readily be done, for example, in new Tetra subscribers that have sufficient bandwidth for this purpose.

This subscriber could be located in one of the walls of this confined area.

The subscriber listens to the control channel and synchronizes to it both in frequency and time. The subscriber also measures the received signal strength for the control channel. By taking into account the C/I characteristics of the modulation and the area it needs to cover, the subscriber can estimate what is the power it needs to transmit so that it can mask the control channel signal to any subscriber in the area. We call this subscriber the ‘disabling subscriber’.

As an example, we first consider speaker disabling, which in subscribers supporting dispatch, could be annoying in ‘quiet environments’ such as concert halls, public libraries, etc.

Every T seconds, where T should be a parameter, the ‘disabling subscriber’ with the exact timing of the broadcast channel of the control channel of the system, sends out a command (broadcast mode) to all subscribers in the area to disable their speaker for a period of say N*T seconds.

Since the ‘disabling subscriber’ is synchronized both in time and frequency to the control channel, any other subscriber...