Method for dynamically mapping channels for new GSM frequency bands

A method for providing for a dynamic mapping of channel numbers to physical frequencies for some cells of a cellular telephone system, the method for use in case of a cellular telephone system representing physical frequencies by channel numbers and providing a fixed mapping of channel numbers to physical frequencies, the cellular telephone system composed of a plurality of public land mobile networks each of which provide coverage in a different set of cells of the cellular telephone system, the dynamic mapping to be used by a particular public land mobile network and so for all the cells for which cellular communication is provided by the particular public land mobile network, the method comprising the steps of:

• a) selecting a set of physical frequencies;
• b) selecting from the channel numbers a set of channel numbers sufficient in number to correspond, one-to-one, to the selected physical frequencies;
• c) determining a dynamic mapping of the selected physical frequencies to the selected set of channel numbers;
• and
• d) providing to mobile phones in the cells of the public land mobile network an information element indicating the dynamic mapping, the information element including information sufficient to determine the first and last channel number of the dynamic mapping and the first and last physical frequency of the dynamic mapping;
• wherein the step of providing the information element indicating the dynamic mapping is performed in a way that is compatible with an existing channel numbering space, and so allows keeping unchanged any existing signaling messages;
• and further wherein to provide for a change in a dynamic mapping being used by a public land mobile network, a duplicated mapping is broadcast by the public land mobile network in which two non-overlapping sets of channel numbers are mapped, the broadcasting being continued for a predetermined time period assumed to be of sufficient extent that any mobile phones operating in the cells of the public land mobile network will have decoded the duplicated mapping.

An apparatus for providing a dynamic mapping of channel numbers to physical frequencies for some cells of a cellular telephone system, the apparatus for use in case of a cellular telephone system representing physical frequencies by channel numbers and providing a fixed mapping of channel numbers to physical frequencies, the cellular telephone system composed of a plurality of public land mobile networks each of which provide coverage in a different set of cells of the cellular telephone system, the dynamic mapping to be used by a particular public land mobile network and so for all the cells for which cellular communication is provided by the particular public land mobile network, the apparatus comprising:

• a) means for selecting a set of physical frequencies;
• b) means for selecting from the channel numbers a set of channel numbers sufficient in number to correspond, one-to-one, to the selected physical frequencies;
• c) means for determining a dynamic mapping of the selected physical frequencies to the selected set of channel numbers;
• and
• d) means for having the public land mobile network provide to mobile phones in the cells of the public land mobile network an information element indicating the dynamic mapping, the information element including information sufficient to determine the first and last channel number of the dynamic mapping and the first and last physical frequency of the dynamic mapping;
• wherein the information element indicating the dynamic mapping is provided in a way that is compatible with an existing channel numbering space, and so allows keeping unchanged any existing signaling messages.

An apparatus for providing for a dynamic mapping of channel numbers to physical frequencies for some cells of a cellular telephone system, the apparatus for use in case of a cellular telephone system representing physical frequencies by channel numbers and providing a fixed mapping of channel numbers to physical frequencies, the cellular telephone system composed of a plurality of public land mobile networks each of which provide coverage in a different set of cells of the cellular telephone system, the dynamic mapping to be used by a particular public land mobile network and so for all the cells for which cellular communication is provided by the particular public land mobile network, the apparatus comprising:

• a) means for selecting a set of physical frequencies;
• b) means for selecting from the channel numbers a set of channel numbers sufficient in number to correspond, one-to-one, to the selected physical frequencies;
• c) means for determining a dynamic mapping of the selected physical frequencies to the selected set of channel numbers;
• and
• d) means for having the public land mobile network provide to mobile phones in the cells of the public land mobile network an information element indicating the dynamic mapping, the information element including information sufficient to determine the first and last channel number of the dynamic mapping and the first and last physical frequency of the dynamic mapping;
• wherein the information element indicating the dynamic mapping is provided in a way that is compatible with an existing channel numbering space, and so allows keeping unchanged any existing signaling messages;
• and further wherein to provide for a change in a dynamic mapping being used by a public land mobile network, the apparatus includes means for having the public land mobile network broadcast a duplicated mapping in which two non-overlapping sets of channel numbers are mapped, the broadcasting being continued for a predetermined time period assumed to be of sufficient extent that any mobile phones operating in the cells of the public land mobile network will have decoded the duplicated mapping.