Introduction to Telephones and Telephone Systems (3rd Ed.) by A. Michael Noll: A great system-level overview covering instruments, transmission media, switching, and signaling.
Understanding Telephone Electronics by Carr, Winder, & Bigelow: Focuses on the electronic components and workings of telephone systems.
Introduction to Telephones and Telephone Systems (3rd Ed.) by A. Michael Noll: A great system-level overview covering instruments, transmission media, switching, and signaling.
Understanding Telephone Electronics by Carr, Winder, & Bigelow: Focuses on the electronic components and workings of telephone systems.