Computer-implemented inbuilding prediction modeling for cellular telephone systems

• US 6,338,031 B1
• Filed: 09/23/1999
• Issued: 01/08/2002
• Est. Priority Date: 07/31/1997
• Status: Expired due to Term

• Current Assignee: Cellco Partnership, Inc. (Verizon Communications Inc.)
• Original Assignee: Cellco Partnership, Inc. (Verizon Communications Inc.)
• Inventors: Lee, Jau Young, Lee, William Chien-Yeh
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): Broda, Samuel
• Application Number:
  US09/404,022
• Time in Patent Office: 838 Days
• Field of Search: 703/1, 703/2, 703/6, 703/13, 703/22, 702/57, 455/62
• US Class Current: 703/13
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04B 17/3913 Predictive models, e.g. based on neural network models
• CPC Class Codes: H04W 16/20 for indoor coverage or short range network deployment

Abstract

A computer-implemented modeling tool for cellular telephone systems predicts signal strength under real conditions within a building, by considering the effects of inter-building and intra-building structures on transmitted signals. The modeling tool gives more accurate predictions under line of sight conditions, when obstructions occur due to inter-building and intra-building structures.

Claims

1. A method for modeling a communications system comprising a transmitter having an antenna and a receiver having an antenna located at a distant location from the transmitter antenna, comprising the steps of:

determining a line-of-sight signal strength between the transmitter antenna and the receiver antenna; and

computing enhancements and degradations to the line-of sight signal strength from at least one structure between the transmitter antenna and the receiver antenna;

wherein the computing step further comprises the step of computing a strength P_r of a signal received at the receiver antenna from the transmitter antenna, wherein the strength P_r is computed as;

2. The method of claim 1, wherein the computing step further comprises the steps of:

(1) calculating a line of sight loss L_los for each segment d_i;

$L_{\mathrm{los}}=\frac{4<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>d_i}{\mathrm{\lambda <br><br>}}$

where n is a number of segments, λ

is a wavelength of a transmitted signal, and d_i is a length of segment I; and

(2) accumulating the line of sight loss L_los for all segments d_i as L_los.

3. The method of claim 1, wherein the computing step further comprises the steps of:

(1) calculating a standard room loss L_room of each segment i that intersects a standard room as;

4. The method of claim 1, wherein the computing step further comprises the steps of:

(1) calculating a special room loss L_specialroom of each segment i that intersects a special room as;

5. The method of claim 1, wherein the computing step further comprises the steps of:

(1) calculating an outside loss L_outside of each segment i that is outside the building as;

6. An article of manufacture comprising a program storage medium readable by a computer having a memory, the medium tangibly embodying one or more programs of instructions executable by the computer to perform method steps for modeling a communications system, the method comprising the steps of:

determining a line-of-sight signal strength between the transmitter antenna and the receiver antenna; and

computing enhancements and degradations to the line-of sight signal strength from at least one structure between the transmitter antenna and the receiver antenna;

wherein the computing step further comprises the step of computing a strength P_r of a signal received at the receiver antenna from the transmitter antenna, wherein the strength P_r is computed as;

7. The article of manufacture of claim 6, wherein the computing step further comprises the steps of:

(1) calculating a line of sight loss L_los for each segment d_i;

$L_{\mathrm{los}}=\frac{4<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>d_i}{\mathrm{\lambda <br><br>}}$

where n is a number of segments, λ

is a wavelength of a transmitted signal, and d_i is a length of segment I; and

(2) accumulating the line of sight loss L_los for all segments d_i as L_los.

8. The article of manufacture of claim 6, wherein the computing step further comprises the steps of:

(1) calculating a standard room loss L_room of each segment i that intersects a standard room as;

9. The article of manufacture of claim 6, wherein the computing step further comprises the steps of:

(1) calculating a special room loss L_specialroom of each segment i that intersects a special room as;

10. The article of manufacture of claim 6, wherein the computing step further comprises the steps of:

(1) calculating an outside loss L_outside of each segment i that is outside the building as;

11. A computerized apparatus for modeling a communications system, comprising:

a computer;

means, performed by the computer, for determining a line-of-sight signal strength between the transmitter antenna and the receiver antenna; and

means, performed by the computer, for computing enhancements and degradations to the line-of sight signal strength from at least one structure between the transmitter antenna and the receiver antenna;

wherein the means for computing further comprises means for computing a strength P_r of a signal received at the receiver antenna from the transmitter antenna, wherein the strength P_r is computed as;

12. The apparatus of claim 11, wherein the means for computing further comprises:

(1) means for calculating a line of sight loss L_los for each segment d_i;

$L_{\mathrm{los}}=\frac{4<br><br>\mathrm{\pi <br><br>}<br><br>\text{\hspace{1em}<br><br>}<br><br>d_i}{\mathrm{\lambda <br><br>}}$

where n is a number of segments, λ

is a wavelength of a transmitted signal, and d_i is a length of segment I; and

(2) means for accumulating the line of sight loss L_los for all segments d_i as L_los.

13. The apparatus of claim 11, wherein the means for computing further comprises:

(1) means for calculating a standard room loss L_room of each segment i that intersects a standard room as;

14. The apparatus of claim 11, wherein the means for computing further comprises:

(1) means for calculating a special room loss L_specialroom of each segment i that intersects a special room as;

15. The apparatus of claim 11, wherein the means for computing further comprises:

(1) means for calculating an outside loss L_outside of each segment i that is outside the building as;