US 6,091,955 A · Increasing the capacity of a cellular radio network

Abstract

A cellular radio network and a method for increasing traffic carrying capacity in a cellular network in which the operating frequency spectrum of the cellular network has been divided so that typically both regular frequencies and super-reuse frequencies are employed in each cell. The regular frequencies use a conventional frequency reuse pattern to provide seamless overall coverage (overlay). A very tight frequency reuse pattern is used for the super-reuse frequencies to provide additional capacity (underlay). The cellular network controls the division of traffic into regular and super-reuse frequencies by radio resource allocation at the call set-up phase and later on during the call by handover procedure. The cellular network continuously monitors the downlink co-channel interference of each super-reuse frequency in the cell separately for each ongoing call. The call is handed over from a regular frequency to a super-reuse frequency when the co-channel interference level on the super-reuse frequency is sufficiently low. When the co-channel interference level on the super-reuse frequency deteriorates, the call is handed over from the super-reuse frequency back to the regular frequency.

Claims28

Dependent claims

A cellular radio network including allocated radio frequencies reused in cells, comprising:

said allocated radio frequencies being divided into regular radio frequencies for which lower frequency reuse is utilized to achieve a seamless overall coverage, and super-reuse frequencies to which high frequency reuse is applied to provide a high traffic carrying capacity;
at least some of said cells having both at least one regular frequency and at least one super-reuse frequency, so that said at least one regular frequency is intended to serve primary in cell boundary regions and said at least one super-reuse frequency is intended to serve primary in the vicinity of a base station;
and
a controller which controls traffic load distribution in a cell between said at least one regular and said at least one super-reuse frequency by intra-cell handovers induced by estimated interference on said at least one super-reuse frequency,
wherein a BCCH frequency of the cell is a regular frequency, and wherein a radio frequency assigned in call-setup and handover from another cell is always a regular frequency.

2 more elements

A method for increasing traffic carrying capacity in a cellular radio system, comprising:

dividing radio frequencies of said cellular radio network into regular radio frequencies for which lower frequency reuse is utilized to achieve seamless overall coverage, and super-reuse frequencies to which higher frequency reuse is applied to provide a high traffic carrying capacity;
allocating to at least some cells of said cellular radio network both at least one regular frequency and at least one super-reuse frequency so that said regular frequency is intended to serve primarily in cell boundary regions and said super-reuse frequency is intended to serve in a vicinity of a base station;
controlling traffic load distribution in a cell between said at least one regular and said at least one super-reuse frequency by intra-cell handovers induced by estimated interference on said at least one super-reuse frequency;
allocating a regular frequency as a BCCH frequency of said cell in each case;
and
always assigning a regular frequency in call set-up and in a handover from another cell in each case.

3 more elements

A cellular radio network including allocated radio frequencies reused in cells, comprising:

said allocated radio frequencies being divided into regular radio frequencies for which lower frequency reuse is utilized to achieve a seamless overall coverage, and super-reuse frequencies to which high frequency reuse is applied to provide a high traffic carrying capacity;
at least some of said cells having both at least one regular frequency and at least one super-reuse frequency, so that said at least one regular frequency is intended to serve primary in cell boundary regions and said at least one super-reuse frequency is intended to serve primary in the vicinity of a base station;
and
a controller which controls traffic load distribution in a cell between said at least one regular and said at least one super-reuse frequency by intra-cell handovers induced by estimated interference on said at least one super-reuse frequency,
wherein a BCCH frequency of the cell is a regular frequency, and
wherein a radio frequency assigned in call-setup is always a regular frequency.

3 more elements

A method for increasing traffic carrying capacity in a cellular radio system, comprising:

dividing radio frequencies of said cellular radio network into regular radio frequencies for which lower frequency reuse is utilized to achieve seamless overall coverage, and super-reuse frequencies to which higher frequency reuse is applied to provide a high traffic carrying capacity;
allocating to at least some cells of said cellular radio network both at least one regular frequency and at least one super-reuse frequency so that said regular frequency is intended to serve primarily in cell boundary regions and said super-reuse frequency is intended to serve in a vicinity of a base station;
controlling traffic load distribution in a cell between said at least one regular and said at least one super-reuse frequency by intra-cell handovers induced by estimated interference on said at least one super-reuse frequency;
allocating a regular frequency as a BCCH frequency of said cell in each case;
and
always assigning a regular frequency in call set-up in each case.

3 more elements

Dependencies are inferred from the claim text.

Increasing the capacity of a cellular radio network

Life of this patent

Increasing the capacity of a cellular radio network

Life of this patent

Abstract

Claims28