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Browse Prior Art Database

Preventing Wireless LAN Access outside intended area

IP.com Disclosure Number: IPCOM000015914D
Original Publication Date: 2002-May-17
Included in the Prior Art Database: 2003-Jun-21
Document File: 4 page(s) / 59K

Publishing Venue

IBM

Abstract

1. Introduction

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Preventing Wireless LAN Access outside intended area

1. Introduction

Wireless LANs [1] are an easy to install alternative to wired LAN solutions. Connection to the LAN is done by a WLAN Card connecting wirelessly to one or more access points (APs, antennas). These antennas have to be placed in such a way, that any location inside, e.g. the companies buildings, is able to give access to at least one AP. Since the antenna signal is distributed radically there is typically also access to the APs near to borders from the outside of the buildings. This situation could cause a security problem, if the area does not belong to the company, or if it can easily be accessed by others
(e.g. parking facilities for customers). Intruders can wirelessly tap in on the company's network.

2. Problem statement

Following the above mentioned security issues the problem is to avoid access to WLANs outside the intended areas.

3. Solution

The present invention provides an antenna system on the walls of the buildings for disabling any access to the WLAN from the outside.

WLAN uses special frequency bands to establish the communication. The present invention consists of a set of paraboloic antennas (like satellite receiver antennas) sending out noise over the complete spectrum of the WLAN bands. Because of the paraboloic shield the noise can be directed in a specific angle (e.g. 180° for sections of walls without corners). The present solution consists of placing noise antennas on the outside or even the inside (!) of the building walls directed to the outside covering the complete area outside the building. This allows for restricting the access to the WLAN to the inside of the building even though APs will have to be placed near the walls of the building.

Figure 1 illustrates the radial areas covered outside the building for a WLAN in standard mode of operation, which we want to avoid.

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AP3

Figure 1: An exam...