US 2003/0073441 A1Published application

Method of and apparatus for creating constraint matrices

AssigneeSociete Francaise du Radiotelephone

InventorImad Fattouch

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Abstract

A method for generating constraints matrices to be used in planning a cellular, wireless telephone network, wherein, for a given number of specified carrier frequencies (fi, fj) to be allocated to a plurality of radio base stations (11-14) of specified positions and transmission powers that act as a server cell or an interfering cell, said method comprising the following stages: predicting the field strength C of the field received in a mesh in the service zone at one of the predetermined frequencies (fi) of the server cell, computing, in each of the meshes, the strength I of the interference field generated by each of the other cells deemed interfering cells, calculating the value of the ratio C/I for the “server” cell where I is the field strength of the interfering field received in the mesh and larger than a predetermined value of the “MINI_INTERFERENCE_FIELD”, by integrating over the entire service zone, determining the global interference proportion tbij which shall be displayed or stored in a constraints matrix.

Claims19

Dependent claims

A method of creating constraint matrices to be used in planning a cellular wireless telephone circuit whereby, when there is a given number of predetermined carrier frequencies (fi, fj) to be allocated to a plurality of base radio stations having specific transmission powers with a service zone in order to manage a corresponding plurality of radio cells acting as server or interfering cells, comprising the following steps:

according to the positions of each mesh of a server cell, causing a computing system to work out a prediction of the field strength C received in this mesh of the service zone at one (fi) of the predetermined server cell frequencies,
for each of these meshes, causing the computing system to calculate the field strength I of the interfering field generated by each of the cells other than the cell which is deemed to be the cell interfering with the cell in turn deemed to be the server cell by the computing system,
for each of these meshes, causing the computing system to calculate the ratio C/I at the “server” cell, where I is the strength of the interference field generated by each of the other interference cells of the service zone and wherein the strength I of the interference field received in the mesh exceeds a given “MINI_INTERFERENCE_FIELD” value stored by the computing system,
by integrating over the full service zone, causing the computing system to ascertain the global interference rate tbij caused by the interference cells in the server cell, these values thereupon being displayed or stored in a so-called initial constraints matrix by displaying or storing field strengths (Ki, Li, Mi) at the intersections of the rows designating server cells and the columns designating interfering cells,
based on this so-called “initial” constraints matrix, the system determines initialization probabilities of service that represent the probability a given cell shall be the server cell feeding the highest field strength to the cellular phone, the probability of service being inferred from the gap between the predicted field strength and the modifiable value of the “MINI_FIELD” strength stored in a file “Frequencies.txt”.

2 more elements

Apparatus for generating constraints matrices in order to use them in a system with which to plan a cellular wireless telephone network wherein a data system is fitted with means allocating a given number of predetermined carrier frequency values (fi,fj) to be allocated to a plurality of radio base stations (11-14) having specified positions and transmitted powers within a service zone and stored in a database of which the data shall manage a corresponding plurality of radio cells (1-4) that act as server or interfering cells, said apparatus also including means which shall work out, according to the positions of each mesh (P) of a server cell, a predicted value C of received field strength within this mesh of the service zone at one of the predetermined frequencies (fi) of the server cell, further including

means calculating the field strength I of the interference field lo for each of the said meshes and created by each of the cells that the system deems being interfering cell(s) with respect the cell in turn deemed being the server cell by the computing system, and means storing said field strengths I,
means calculating with respect to each of said meshes the value of a ratio C/I with respect to the “server cell”, where I is the interference field strength caused by each of the other interfering cells of the service zone, the value of the received interference field strength I received in the mesh being larger than a predetermined “MINI_INTERFERENCE-FIELD” strength initially stored by the computing system,
means integrating over the full service zone, the computing system calculating the global interference proportion tbij of the server cell caused by the interfering cells;
said values then may be displayed or stored by appropriate means in the so-called initial constraints matrix by displaying or storing field strengths (Ki, Li, Mi) at the intersections of the rows designating server cells and the columns designating interfering cells,
means which, based on said so-called “initial” constraints matrix, shall determine initialization service probabilities that represent the probability that a given cell shall be the server cell feeding the highest field strength to the cell phone, the probability of service being inferred from the gap between the predicted field strength and the modifiable field strength of a “MINI_FIELD” field strength stored in a file “Frequencies.txt”.

2 more elements

Dependencies are inferred from the claim text.