Method for controlling indoor electromagnetic signal propagation

• US 5,496,966 A
• Filed: 06/12/1991
• Issued: 03/05/1996
• Est. Priority Date: 06/12/1991
• Status: Expired due to Term

• Current Assignee: Bellsouth Intellectual Property Corporation (AT&T, Inc.)
• Original Assignee: BellSouth Corporation (AT&T, Inc.)
• Inventors: Hightower, Neale C., O'Neil, Douglas R.
• Primary Examiner(s): Ledynh, Bot L.
• Application Number:
  US07/713,858
• Time in Patent Office: 1,728 Days
• Field of Search: 174/35 R, 174/35 MS, 361/800, 361/816, 361/817-818, 307/89-91
• US Class Current: 174/353
• CPC Class Codes: H01Q 1/007 specially adapted for indoor communication
• CPC Class Codes: H01Q 15/0013 said selective devices working as frequency-selective reflecting surfaces, e.g. FSS, dichroic plates, surfaces being partly transmissive and reflective
• CPC Class Codes: H05K 9/0003 Shielded walls, floors, ceilings, e.g. wallpaper, wall panel, electro-conductive plaster, concrete, cement, mortar

Abstract

A system for the establishment and control of an electromagnetic signal propagation environment containing a particular set of desirable radio frequency characteristics within a bounded area. The bounded area is typically either a business office environment or a residential environment. The electromagnetic signal propagation control system provides interference rejection by preventing electromagnetic interference signals from entering an enclosure to interfere with an enclosed communications system or by preventing signals generated by the enclosed communications system from exiting the enclosure and interfering with another nearby communications system. The system also customizes the electromagnetic signal environment to improve communications within interior areas otherwise blocked from signal propagation and to absorb signal reflections from interior surfaces that may cause interference for the enclosed communications system. In addition, the system selectively rejects or accepts electromagnetic signals passing into and exiting from the enclosure to permit desired radio frequency communications between a communications system inside the enclosure and a second system outside the enclosure. The system is installed by utilizing aesthetically appealing building materials comprising conductive, absorptive, reflective, or frequency selective electromagnetic characteristics.

Claims

1. Method for selective control of the propagation of electromagnetic signals including the signals of at least one communications system operating within a certain frequency range throughout a bounded region, the method comprising the steps of:

attenuating said signals within said certain frequency range that enter or leave said bounded region; and

permitting the relatively unattenuated passage across the boundary of signals in at least one second frequency range outside said certain frequency range,

so that users of each communications system within said bounded region can communicate therein without interfering with or interference from another communications system using the same frequency range and located outside said bounded region, and also can communicate through said boundary and outside said bounded region with an exterior communications system operating in said second frequency range.

2. The method of claim 1 and further comprising the step of:

leveling selected signals in said certain frequency range and within said bounded region such that the propagation of said selected signals is relatively uniform throughout said bounded region so as to provide effective communications operations by said communications system operating within said certain frequency range.

3. Method for selective control of the propagation of electromagnetic signals including the signals of a communications system operating within a certain frequency range throughout a bounded region defining a space enclosed by structural means, the method comprising the steps of:

attenuating to a predefined noninterference level said signals within said certain frequency range that enter or leave said bounded region;

permitting the relatively unattenuated passage across the boundary of signals in at least one second frequency range outside said certain frequency range; and

customizing selected signals in said certain frequency range and within said bounded region such that the propagation of said selected signals is relatively uniform throughout said bounded region so as to provide effective communications operations by said communications system operating within said certain frequency range,

so that users of each communications system within said bounded region can communicate therein without interfering with or interference from another communications system using the same frequency range and located outside said bounded region, and also can communicate through the boundary and outside said bounded region with an exterior communications system operating in said second frequency range.