US 5,915,221 AGranted

Neighbor cell list creation and verification in a telecommunications system

AssigneeTelefonaktiebolaget LM Ericsson

InventorsFrancois Sawyer, Andre Beliveau

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Abstract

A method and system for neighbor cell list creation and verification in a telecommunications system is provided. Over a period of time measurements are performed on signals transmitted and received on measurement channels of cells neighboring the cell for which a neighbor cell list is being created. The results of the signal measurements are used to create an ordered list of the measurement channels on which the measurements were done. A neighbor cell list containing a desired number of cells is then created by placing a certain number of cells having the most interfered measurement channels in the neighbor cell list. The invention also presents a method and system for verifying an existing neighbor cell list. In the method and system measurements are performed on measurement channels of neighbor cells over a period of time. Periodically the measurement results are checked to determine if cells should be added to or deleted from the existing neighbor cell list.

Claims16

Dependent claims

In a cellular telecommunications system comprising a plurality of mobile stations, a first cell, and a plurality of neighbor cells, said neighbor cells each comprising at least one base station transmitting and receiving on one or more measurement channels, a method of creating a neighbor cell list for said first cell, said neighbor cell list used for transmission to mobile stations thereby enabling mobile stations to select candidate cells for handoff from said first cell, said method comprising the steps of:

establishing a first neighbor cell list for said first cell;
over the course of a plurality of calls by mobile stations within said first cell:
measuring by those mobile stations in said first cell of signal strength on measurement channels of a group of neighbor cells including cells not in the first neighbor list;
and
sending the signal strength measurements by those mobile stations to the cellular telecommunications system;
and
processing by the cellular telecommunications system after the plurality of calls of the mobile station sent signal strength measurements, said step of processing including the steps of:
creating an ordered list of said measurement channels, said list ordered according to said signal strength measurements obtained by the mobile stations over the course of the plurality of calls;
determining one or more of the measurement channels from said ordered list having highest signal strength;
and
modifying said first neighbor cell list for said first cell to include the neighbor cells associated with said determined one or more measurement channels having highest signal strength.

8 more elements

In a cellular telecommunications system comprising a plurality of mobile stations, a first cell and a plurality of neighbor cells, each of said neighbor cells comprising a base station transmitting and receiving on one or more measurement channels, a method of verifying a neighbor cell list for said first cell, said neighbor cell list used for transmission to mobile stations thereby enabling mobile stations to select candidate cells for handoff from said first cell, said method comprising the steps of:

assigning a first group of said neighbor cells to said neighbor cell list;
over the course of a plurality of calls by mobile stations within said first cell:
measuring by those mobile stations in said first cell of signal strength on a measurement channel of each of said neighbor cells including cells not in the first group;
and
sending the signal strength measurements by those mobile stations to the cellular telecommunications system;
and
processing by the cellular telecommunications system after the plurality of calls of the mobile station sent signal strength measurements, said step of processing including the steps of:
creating an ordered list of said neighbor cells, said list ordered according to said signal strength measurements obtained by the mobile stations over the course of the plurality of calls;
and
reconfiguring said neighbor cell list according to said created ordered list, said step of reconfiguring comprising the steps of:
determining if any of said neighbor cells on the created ordered list have a signal strength measurement above a threshold value;
and
assigning those neighbor cells from the created ordered list having a signal strength measurement above said threshold value to said neighbor cell list.

10 more elements

In a cellular telecommunications system comprising a plurality of mobile stations, a first cell, and a plurality of neighbor cells, said neighbor cells each comprising at least one base station transmitting and receiving on one or more measurement channels, a method for creating a neighbor cell list for said first cell, said neighbor list for transmission to mobile stations thereby enabling mobile stations to select candidate cells for handoff from said first cell, said method comprising the steps of:

establishing a first neighbor cell list for said first cell;
over the course of a plurality of calls by mobile stations within said first cell:
measuring by a base station for the first cell of signal strength on measurement channels of a group of neighbor cells including cells not in the first neighbor list;
and
sending the signal strength measurements by the base station to the cellular telecommunications system;
and
processing by the cellular telecommunications system after the plurality of calls of the base station sent signal strength measurements, said step of processing including the steps of:
creating an ordered list of said measurement channels, said list ordered according to said signal strength measurements obtained by the base station over the course of the plurality of calls;
determining one or more of the measurement channels from said ordered list having highest signal strength;
and
modifying said first neighbor cell list for said first cell to include the neighbor cells associated with said determined one or more measurement channels having highest signal strength.

8 more elements

In a cellular telecommunications system comprising a plurality of mobile stations, a first cell and a plurality of neighbor cells, each of said neighbor cells comprising a base station transmitting and receiving on one or more measurement channels, a method for verifying a neighbor cell list for said first cell, said neighbor cell list used for transmission to mobile stations thereby enabling mobile stations to select candidate cells for handoff from said first cell, said method comprising the steps of:

assigning a first group of said neighbor cells to said neighbor cell list;
over the course of a plurality of calls by mobile stations within said first cell:
measuring signal strength by a base station for said first cell on measurement channels of each of said neighbor cells including cells not in the first group;
and
sending the signal strength measurements by the base station to the cellular telecommunications system;
and
processing by the cellular telecommunications system after the plurality of calls of the base station sent signal strength measurements, said step of processing including the steps of:
creating an ordered list of said neighbor cells, said list ordered according to said signal strength measurements obtained by the base station over the course of the plurality of calls;
and
reconfiguring said neighbor cell list according to said created ordered list, said step of reconfiguring comprising the steps of:
determining if any of said neighbor cells on the created ordered list have a signal strength measurement above a threshold value;
and
assigning those neighbor cells on the created ordered list having a signal strength measurement above said threshold value to said neighbor cell list.

10 more elements

Dependencies are inferred from the claim text.