US 6,477,377 B2 · Cellular radiotelephone systems and methods that broadcast a common control channel over multiple radio frequencies

Abstract

Cellular radiotelephone systems and methods communicate with cellular radiotelephones via multiple base stations. Radiotelephone traffic channels are used by the base stations for radiotelephone communications with the telephones. A common control channel is transmitted by the base stations, to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels. The common control channel is transmitted by a first one of the base stations over a first radio frequency and is transmitted by a second one of the base stations over a second radio frequency that is different from the first radio frequency. By providing a common control channel, excess control channel capacity can be reduced, thereby conserving control channel radio spectrum. Moreover, by transmitting the common control channel using multiple radio frequencies, the radio frequencies can be selected to reduce and preferably eliminate interference.

Claims36

Dependent claims

A cellular radiotelephone system that communicates with a plurality of cellular radiotelephones, comprising:

a plurality of base stations;
a plurality of radiotelephone traffic channels that are used by the base stations for radiotelephone communications with the radiotelephones;
and
a common control channel that is transmitted synchronously by the base stations to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels, wherein the common control channel transmits the same information by the base stations;
and
the common control channel being transmitted by a first one of the base stations over a first radio frequency, and being transmitted by a second one of the base stations over a second radio frequency that is different from the first radio frequency.

3 more elements

A cellular radiotelephone system that communicates with a plurality of cellular radiotelephones, comprising:

a plurality of base stations;
a plurality of radiotelephone traffic channels that are used by the base stations for radiotelephone communications with the radiotelephones;
a common control channel that is transmitted synchronously by the base stations to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels, wherein the common control channel transmits the same information by the base stations;
a first one of the base stations comprising means for transmitting the common control channel over a first radio frequency;
and
a second one of the base stations comprising means for transmitting the common control channel over a second radio frequency that is different from the first radio frequency.

3 more elements

A method of controlling a cellular radiotelephone system including a plurality of radiotelephone traffic channels that are used by a plurality of base stations for radiotelephone communications with a plurality of radiotelephones, using a common control channel that is transmitted synchronously by the base stations to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels, wherein the common control channel transmits the same information by the base stations, the method comprising the steps of:

transmitting the common control channel from a first one of the base stations over a first radio frequency;
and
transmitting the common control channel from a second one of the base stations over a second radio frequency that is different from the first radio frequency.

A method of initializing a cellular radiotelephone system including a plurality of radiotelephone traffic channels that are used by a plurality of base stations for radiotelephone communications with a plurality of radiotelephones, using a common control channel that is transmitted by the base stations to control radiotelephone communications with the radiotelephones over the radiotelephone traffic channels, wherein the common control channel transmits the same information by the base stations, the method comprising the steps of:

determining whether the common control channel can be transmitted from the plurality of base stations over a first radio frequency without interference;
if the common control channel cannot be transmitted from the plurality of base stations over the first radio frequency without interference, identifying at least one of the base stations that cannot transmit the common control channel over the first radio frequency without interference;
and
assigning a second radio frequency that is different from the first radio frequency for transmission of the common control channel by the at least one of the base stations so identified.

1 more element

Dependencies are inferred from the claim text.

Cellular radiotelephone systems and methods that broadcast a common control channel over multiple radio frequencies

Life of this patent

Cellular radiotelephone systems and methods that broadcast a common control channel over multiple radio frequencies

Life of this patent

Abstract

Claims36