Unsolved problems of applied information theory

Fast development of wireless networks created a large number of new challenges and problems. Many authors note growing decrease of a capability of modern communications and information theory to impróve the PHY layer performance. The paper discusses the sources of these difficulties and new information measures permitting to solve at least part of them using feedback channels. The backgrounds of original analytical approach to the accurate evaluation and impróvement of the spectrał and energy efficiency of wireless sensor networks are discussed also. Examples of new approach applications are given.