Channel selection and clarity improvement for digital cordless telephones operating in an overlapped range

Abstract

When a plurality of cordless telephones (e.g., digital cordless telephones) are used within range of one another, base units of one or more of the digital cordless telephones may receive transmissions from others of the digital cordless telephones. Conventionally, the base unit would simply ignore information relating to that received from an unintended remote handset, i.e., a remote handset having a security code which fails to match that of the receiving base unit. However, in accordance with the principles of the present invention, information regarding the unique security code received with respect to other remote handsets (i.e., those having security codes which do not match that of the receiving base unit), are logged and used in a way which provides a unique best available channel list to each of the digital cordless telephones so that similar digital cordless telephones operating in a similar environment do not attempt selection of channels in a similar way (causing channel inclarity and/or interference). In a first embodiment, the list of best available channels is randomized based on the unique security code of the relevant digital cordless telephone. In a second embodiment, the list of best available channels is randomized only when another digital cordless telephone becomes within transmission range of the relevant digital cordless telephone. In a third embodiment, a list of best available channels is uniquely indexed for each digital cordless telephone based on a ranking of the digital cordless telephones within transmission range of one another. For instance, the highest ranking digital telephone in an environment with three digital cordless telephones attempts use of, preferably in order, the 1 , 4 , 7 , 10 , etc. channels.