Computer networks need novel communication theory for transmitting data from sources to destinations within a predetermined restrict period of time according to a given quality of service (QoS). This book provides an analysis of min-plus algebra that is applied to network calculus in computer networks. The key contribution of this book is to discuss the analytical expressions of identity in min-plus algebra. Overall, this book can be used as a reference for researchers, engineers and postgraduates in the fields of communication networks, internet studies and cyber-physical networking systems in the aspect of applied functional analysis, in addition to min-plus algebra used in network calculus for computer scientists.