Method for determination of the minimum distance between frequency channels within pre-selected base station cells

• US 6,987,973 B2
• Filed: 12/04/2001
• Issued: 01/17/2006
• Est. Priority Date: 05/23/2001
• Status: Expired due to Fees

• Current Assignee: Polska Telefonia Cyfrowa Sp. Z O.O. (Deutsche Telekom AG)
• Original Assignee: Polska Telefonia Cyfrowa Sp. Z O.O. (Deutsche Telekom AG)
• Inventors: Wawrzynski, Pawel, Lehmann, Grzegorz
• Primary Examiner(s): Perez-Gutierrez, Rafael
• Assistant Examiner(s): Karikari, Kwasi
• Application Number:
  US10/478,972
• Publication Number:
  US 20040157615A1
• Time in Patent Office: 1,505 Days
• Field of Search: 455/450, 455/446, 455/447, 455/296, 455/134, 455/67.3
• US Class Current: 455/450
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

The method consists in the use of the average network traffic data and a series of measurements taken within a part of a network, along with the recording of the signals, received from all base stations within reach of a given point. The measurement area is divided into polygonal sections, relating to specific P measurements and the total area of such section represents the weight of a given measurement. Subsequently, based on the most powerful signal criterion, individual P measurements are assigned to specific network cells. Further on, the based on the differences between signal power value calculated, measurement weights and the assumed distances between channels, values of certain formulae are calculated, which then provide the basis for determination of the minimum distances between channels.

Claims

1. Method for determination of the minimum distances between channels of pre-selected mobile telephony network cells, characterised by comprising of the steps:

defining at least two specific Z_i distances, to which a specific signal power delta value is then assigned;

taking a series of measurements (P_i) along a pre-defined measurement routes located within area of the cells of pre-selected base stations, and recording for each of these measurements (P_i);

a) reference numbers of the channels carrying the signals received,

b) power of the signal within each channel and base station IDs,

c) geographic co-ordinates of a point where the measurement is taken;

registering for each cell average peak traffic and average daily traffic;

registering for each pair of cells average peak- and daily number of calls handed over from cell 1 to cell 2 and vice versa;

determining for each P_i measurement a sector, where a distance between any point therein and the point of the P_i measurement is shorter than a distance between such point and the point of other P_i measurement;

determining a W_i weight of each P_i measurement, equal to the area of each such sector;

assigning each P_i measurement to a particular S_i serving cell, selecting that with the most powerful signal as received in a given location;

calculating for each P_i(S) measurement assigned to a pre-selected S serving cell a difference between the signal power from the S cell and the power of each of the other signals received from other cells, referred to as K_i(S) cells;

computing for each of the defined Z_i distances SUM_SK(Z_i) sums of the W_i(S) weights for all types of those P_i(S) measurements, for which the calculated power difference is smaller than the signal power delta assigned to the specific Z_i distance;

calculating for each of the K_i(S) cells a q_SK(Z_i) ratio of interference with a pre-selected S_i serving cell, equal to the quotient of SUM_SK(Z_i) and the total W_i(S) weights for all P_i(S) measurements applicable to this same S_i serving cell;

calculating, for each K_i(S) analysed cell, a value of the following formula;

(α

*T_T(S)+β

T_B(S)+δ

*H_T(S)+γ

*H_B(S))*q_SK(Z_i)

 

where α

, β

, δ

i γ

represent non-negative ratios selected by the system operator, T_T(S) represents the average daily traffic in the S_i cell, T_B(S) represents the average peak traffic in the serving cell, H_T(S) represents the daily average number of calls, handed over between the S and K(S) cells, and H_B(S) stands for the peak average number of such handed over calls; and

assigning for each K_i(S) cell a minimum distance between a channel in such K_i(S) and a channel in the pre-selected S serving cell, equal to the largest Z_i distance for which the value of the above formula is smaller than, or equals one.