Method for determining the spatial distribution of the traffic volume within a mobile radio communications network

• US 6,085,095 A
• Filed: 02/12/1998
• Issued: 07/04/2000
• Est. Priority Date: 02/14/1997
• Status: Expired due to Fees

• Current Assignee: Alcatel SA (Nokia Corporation)
• Original Assignee: Alcatel SA (Nokia Corporation)
• Inventors: Collmann, Ralf
• Primary Examiner(s): Urban, Edward F.
• Assistant Examiner(s): Gesesse, Tilahun
• Application Number:
  US09/023,409
• Time in Patent Office: 873 Days
• Field of Search: 455/456, 455/457, 455/453, 455/226.2, 455/67.4, 455/67.6, 455/422, 455/435, 455/423, 455/446
• US Class Current: 455/453
• CPC Class Codes: H04B 17/3911 Fading models or fading generators
• CPC Class Codes: H04M 3/36 Statistical metering, e.g. recording occasions when traffic exceeds capacity of trunks
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

For determining the spatial distribution of the traffic volume within a radio cell of a cellular mobile radio communications network, a test signal transmitter is usually installed at a test location. Each mobile station which receives the test signal, measures and reports the receive level to a computer for evaluating the test location. The test location is deemed to be suitable for the installation of a new base station if the majority of the mobile stations receives a test signal of sufficient strength. In order to provide a simple method for determining the spatial distribution, it is proposed to first subdivide the radio cell (RC1) into several segments or sections (A1, A2, A3, . . . , D4) and to associated respective reference values (e.g. reference receive levels) with these segments or sections. The reference values are calculated with the help of a Radio Communications Network Planning Tool, wherein the distances from the segment or section (C2) to at least two of the base stations (BS1, BS2) can be derived from the reference values. Subsequently, measured values (e.g. the actual receive level) which depend on the length of the radio transmission paths, are determined for each mobile station (MS). After the reference values are compared with the actual values, the respective segment or section (C2) in which the mobile station (MS) is currently located, is determined. A counter state indicating the traffic volume in this segment or section (C2) is then incremented for this segment (C2). A test signal transmitter is not required, because that section (C2) of the cell which has the highest count state, representing the highest traffic volume, has been shown to be a desirable location for a reliever base station, without having to put a test transmitter there.

Claims

1. A method (100) of determining spatial distribution of traffic volume within respective radio cells (RC1 . . . ) of a cellular mobile radio communications network (MRN) with a plurality of base stations (BS1, BS2, BS3), which each serve a respective one of the radio cells (RC1, RC2, RC3), the method comprising the steps of:

determining (130), for each mobile station (MS) within the radio cell (RC1), at least two measured values (M1, M2) which depend on lengths of respective radio transmission paths from the mobile station (MS) to said at least two base stations (BS1, BS2), wherein the radio cell (RC1) is subdivided into several sections (A1, A2, A3, . . . B1, B2, . . . ) wherein with each section (C2) there is associated a reference data set (DS) comprising at least two reference values (RL1, RL2) which specify, for spatial coordinates of the section (C2), radio propagation requirements for radio transmission paths to at least two of the base stations (BS1, BS2), said reference values being characteristic of respective spatial separations from the section (C2) to the at least two base stations (BS1, BS2);

forming (140) from the measured values (M1, M2) an actual data set (DS'"'"'), comparing said actual data set with the reference data sets (DS), wherein each of said reference data sets (DS) is associated with exactly one of the sections (A1, A2, A3, . . . B1, B2, . . . );

determining (150) which section (C2) has a reference data set (DS) which most closely matches the actual data set (DS'"'"') ; and

incrementing (160), for the matching section (C2), a counter state (CNT) which represents traffic volume in the matching section (C2).

2. A method according to claim 1, further comprising the step of

comparing, after a presettable time interval, counter states (CNT) for the respective sections (A1, A2, A3, . . . B1, B2, . . . ), representing respective traffic volumes therein, and identifying that section (B1) with a highest counter state (CNT) as a desirable location for a new base station for the mobile radio communications network (MRN).

3. A method according to claim 1, wherein

said step of determining (130) the measured values comprising measuring signal strength receive levels (M1, M2) which are reduced by attenuation along the radio transmission paths, and thus are a function of the lengths of the paths.

4. A method according to claim 1, wherein said step of determining (130) the measured values comprises measuring signal propagation times of radio signals transmitted on respective radio transmission paths.

5. A method according to claim 1, further comprising the steps of

determining the measured values (M1, M2) of each mobile station (MS) (130) when radio signals transmitted by the base stations (BS1, BS2) are received, and

subsequently transmitting the measured values to the base station (BS1) which services the radio cell (RC1),

and feeding the measured values (M1, M2) as input data to a computation unit (COMP) which is connected to the base station (BS1) and determines mobile station location therefrom.

6. A method according to claim 5, wherein

the input data formed from the measured values (M1, M2) are combined in the computation unit (COMP) into the actual data set (DS'"'"'), and wherein the actual data set (DS'"'"') is compared in the computation unit (COMP) with a reference data set (DS) whose reference values (RL1, RL2) are stored in a database (DE).

7. A computation unit (COMP) for determining the spatial distribution of traffic volume within a radio cell (RC1) of a cellular mobile radio communications network (MRN), wherein the radio cell (RC1) is subdivided into a plurality of sections (A1, A2, A3, . . . B1, B2, . . . ) wherein

the computation unit (COMP) is connected with base stations (BS1, BS2, BS3) with each base station servicing a respective radio cell (RC1, RC2, RC3),

the computation unit (COMP) is connected to a database (DB) storing reference data sets (DS), with each reference data sets (DS) uniquely identifying one of the sections (C2) and comprising at least two reference values (RL1, RL2) which indicate, for the spatial coordinates of the section (C2), radio transmission conditions for radio transmission paths to at least two of the base stations (BS1, BS2) and which make it possible to derive the spatial distances from the section (C2) to the at least two base stations (BS1, BS2),

the computation unit (COMP) within the radio cell (RC1) forms, for each mobile station, at least one actual data set (DS'"'"') from at least two measured values (M1, M2) which depend on the respective lengths of the radio transmission paths between the mobile station (MS) and the at least two base stations (BS1, BS2), and compares the actual data set (DS'"'"') with the reference data sets (DS), and

the computation unit (COMP) indicates the respective section (C2) whose reference data set (DS) is in closest agreement with the actual data set (DS'"'"'), thereby locating the mobile station, and increments for the respective section (C2) a counter state (CNT) which represents the traffic volume for the respective section.

8. A computation unit (COMP) according to claim 7, which after a presettable time interval compares the counter states (CNT) for the sections (A1, A2, A3, B1, B2, . . . ) with each other and identifies a section having a highest counter state (CNT) as a desirable location for a base station to be added to the mobile radio communications network (MRN).

9. A mobile radio communications network (MRN) with a computation unit (COMP) for determining the spatial distribution of the traffic volume within a radio cell (RC1) of a cellular mobile radio communications network (MRN), wherein

the radio cell (RC1) is subdivided into a plurality of sections (A1, A2, A3, . . . B1, B2, . . . ),

the computation unit (COMP) is connected with base stations (BS1, BS2, BS3), with each base station servicing a respective radio cell (RC1, RC2, RC3),

the computation unit (COMP) is connected to a database (DB) for storing reference data sets (DS), with each of the reference data sets (DS) uniquely identifying one of the sections (C2) and comprising at least two reference values (RL1, RL2) which indicate, for the spatial coordinates of the section (C2), radio transmission conditions for radio transmission paths to at least two of the base stations (BS1, BS2) and which make it possible to derive the respective spatial separations from the section (C2) to the at least two base stations (BS1, BS2),

the computation unit (COMP), for each mobile station (MS) within the radio cell (RC1), forms at least one actual data set (DS'"'"') from at least two measured values (M1, M2) which depend on the lengths of the radio transmission paths between the mobile station (MS) and the at least two base stations (BS1, BS2), and compares the actual data set (DS'"'"') with the reference data sets (DS), and the computation unit (COMP) indicates that respective section (C2) whose reference data set (DS) is in closest agreement with the actual data set (DS'"'"'), and increments, for the respective section (C2), a counter state (CNT) which represents the traffic volume for the respective section.

10. A mobile radio communications network (MRN) according to claim 9, wherein, after a presettable time interval, the computation unit (COMP) compares the respective counter states (CNT) for the sections (A1, A2, A3, . . . B1, B2, . . . ) with each other and identifies the respective section (B1) with the highest counter state (CNT) as a desirable location for a base station to be added to the mobile radio communications network (MRN).