Wireless network planning tool

• US 5,710,758 A
• Filed: 09/29/1995
• Issued: 01/20/1998
• Est. Priority Date: 09/29/1995
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Soliman, Samir S., Reynolds, Sheila M.
• Primary Examiner(s): Kizou, Hassan
• Assistant Examiner(s): Yao, Kwang Bin
• Application Number:
  US08/535,999
• Time in Patent Office: 844 Days
• Field of Search: 370/13, 370/18, 370/60.1, 370/95.1, 370/95.3, 370/241, 370/254, 370/320, 370/329, 370/342, 370/318, 455/33.1, 455/33.2, 455/38.3, 455/53.1, 455/54.1, 455/67.1, 455/67.2, 455/67.6, 379/58, 379/59, 379/63, 375/205, 395/500, 395/183.08, 395/183.09
• US Class Current: 370/241
• CPC Class Codes: H04B 17/391 Modelling the propagation channel
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

A novel and improved method and apparatus for planning a wireless telecommunications network. An electronic representation of wireless telecommunications system can be configured within a given market area and the operation of that wireless telecommunications system simulated. The simulation is performed using a set of databases that contain terrain and population information associated with the market area over which the wireless network in configured. To perform the simulation a composite propagation loss matrix and a demand and service vector are generated using the terrain and population information, as well as the configuration of the wireless telecommunications network. Once the composite propagation loss matrix and the demand and service vector are generated an analysis of the reverse link is performed. Subsequently, an analysis of the forward link is performed. During both the reverse and forward link analysis the multiple iterations of analysis are performed until a stable result is achieved. Upon completion of the reverse and forward link analysis, the results of the simulation are displayed in a graphical manner for examination.

Claims

1. A method for testing and optimizing a configuration of a wireless telephone network comprising the steps of:

(a) configuring a set of base stations over a market area having a population distribution;

(b) generating a composite propagation loss matrix containing a set of corresponding propagation loss values between said set of base stations and a set of locations within said market area;

(c) generating a demand and service vector having a population for each location using said population distribution;

(e) assigning each of said set of locations to a base station to which a propagation loss exists with a minimum value;

(f) calculating a sensitivity for each base station based on how many locations are associated with said base station, and said population associated with each location;

(g) determining for each location a base station to which a reverse link signal may be transmitted with minimal reverse link power so as to arrive at said base station with energy substantially equal to said sensitivity; and

(h) recalculating said base station sensitivity using said minimal reverse link power from each location.

2. The method as set forth in claim 1 wherein step (c) is comprised of the step of applying a Poisson random variable generation function to said population on a location by location basis.

3. The method as set forth in claim 1 wherein step (b) is comprised of the steps of:

(b.1) determining a set of locations located within a radius of each base station; and

(b.2) calculating a propagation loss from each location in said set of locations to said base station.

4. The method as set forth in claim 3 wherein step (b.2) is comprised of the step of repeatedly performing the steps of:

determining the distance of a location from said set of locations from said base station;

calculating a free space propagation loss for said location;

setting said propagation loss to said free space propagation loss if said location is in line of sight of said base station; and

calculating a diffraction loss for said location if said location is not in line of sight of said base station, and setting said propagation loss equal to said free space propagation loss plus said diffraction loss, until each point in said set of points has been processed.

5. The method as set forth in claim 1 further comprising the steps of:

(h) setting a received forward link power for each location to an initial value;

(i) determining for each location a set of base station from which a forward link signal is received with sufficient strength to allow demodulation of an associated pilot channel, and incrementing a number traffic channels at each base station from said set of base stations;

(j) calculating a forward link radiated power for each base station using said number of traffic channels; and

(k) calculating said received forward link power for each location using said forward link radiated power.

6. A method for simulating the operation of a wireless telecommunications system operating in accordance with code division multiple access signal modulation techniques, comprising the steps of:

(a) receiving a terrain database, a population database, and a base station configuration database;

(b.1) calculating a set of reverse link connections between said set of base stations and said set of locations requiring a minimum amount of reverse link effective radiated power;

(b.2) calculating a set of received reverse link power values corresponding to said set of base station using said set of reverse link connections;

(b.3) calculating a sensitivity for each base station using said set of received reverse link power values; and

(b.4) performing step (b.1) through (b.3) repeatedly until a stable result has been achieved; and

(c) simulating the forward link operation of the wireless telecommunications system.

7. The method as set forth in claim 6 wherein said terrain data base contains a set of locations and said base station configuration database contains a set of base stations, step (c) is comprised of the steps of:

(c.1) calculating a set of forward link connections between said set of base stations and said set of locations; and

(c.2) calculating a set of received forward link power values corresponding to said set of location using said set of forward link connections; and

(c.3) performing step (c.1 and c.2) repeatedly until a stable result has been achieved.

8. The method as set forth in claim 6 further comprising the steps of displaying said forward link and reverse link operation.

9. The method as set forth in claim 6 wherein step (b) is comprised of the steps of:

(b.1) setting a sensitivity for each base station to an initial value;

(b.2) determining for each location a base station to which a reverse link signal can be transmitted with a minimum reverse link radiated power so as to arrive at said base station with an energy level substantially equal to said sensitivity;

(b.3) calculating a received reverse link power at each base station using said minimum reverse link radiated power from each location; and

(b.4) calculating said sensitivity for each base station using said received reverse link power.

10. The method as set forth in claim 6 wherein step (c) is comprised of the steps of:

(c.1) setting a received forward link power for each location to an initial value;

(c.2) determining for each location a set of base station from which a forward link signal is received with sufficient strength to allow demodulation of an associated pilot channel, allocating a number of traffic channels for each base station from said set of base stations for each location;

(c.4) calculating a forward link radiated power at each base station using said number of traffic channels; and

(c.4) calculating said received forward link power for each location using said forward link radiated power.