Portable radio telephone and methods of operation
AssigneeNokia Mobile Phones Ltd.
InventorsNguyen Quan Tat, Robert Stanley Saunders
Life of this patent
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Abstract
A portable radio telephone (5) communicates with base stations (1, 2) in a digital radio telephone system, such as DECT, employing TDMA transmission. The portable radio telephone is programmed with an algorithm which is operative to select a communication channel by storing a blind slot mask (7) representative of the time slots in each frame which are excluded. The algorithm is operative to check the time slots for availability in a predetermined sequence which corresponds to the temporal sequence of the slots (or the reverse thereof) to promote orderly filling of the time slots at the base stations.
Claims9
A portable radio telephone for communication with base stations in a digital cellular radio telephone system employing transmission by a plurality of carrier frequencies in frames each consisting of a predetermined number of time slots, wherein the portable radio telephone is operative to select for the radio telephone a communication channel, that is a combination of a carrier frequency and a time slot, by storing information concerning time slots in a list, the list including both non-excluded time slots and excluded time slots, the excluded time slots being excluded by the radio telephone or by a transmission from a communicating base station, and checking one channel on each of the non-excluded time slots in the list in a predetermined sequence until an available channel is selected.
A method of communicating between a portable radio telephone and base stations in a digital cellular radio telephone system employing transmission by carrier frequencies in frames each consisting of a predetermined number of time slots, comprising storing information concerning time slots in a list, the list including both non-excluded time slots and excluded time slots, the excluded time slots being excluded by the radio telephone or by a transmission from a communicating base station, and checking one channel on each of the non-excluded time slots in the list in a predetermined sequence until an available channel is selected.
A portable radio telephone for communication with a base station in a digital cellular radio telephone system, comprising:
- a processor for selecting an available communication channel for said portable radio telephone;
- a storage device coupled to said processor;
- and
- a communication channel list stored in said storage device, said communication channel list being logically ordered as a plurality of rows and a plurality of columns, wherein each row represents one of a plurality of carrier frequencies, and each column represents one of a predetermined number of time slots such that each intersection of a row and a column represents one of a plurality of communication channels;
- wherein said processor makes received signal strength measurements and stores information in said communication channel list which represents an amount of signal interference in individual ones of said communication channels;
- wherein said processor examines one channel in each time slot in a predetermined sequence until an available communication channel therein is selected for establishing communications with said base station.
Dependencies are inferred from the claim text.