Electronic – Can you recommend a book on wireless protocol design

The standard IPC-2221, "Generic Standard on Printed Board Design" is quite complete - it covers:

• General Requirements
• Materials
• Mechanical/Physical Properties
• Electrical Properties
• Thermal Management
• Component and Assembly Issues
• Holes/Interconnections
• General Circuit Feature Requirements
• Documentation
• Quality Assurance

It is intended to

establish design principles and recommendations that shall be used in conjunction with the detailed requirements of a specific interconnecting structure sectional standard ... to produce detailed designs intended to mount and attach passive and active components.

(and you can check out the other IPC dependencies related to specific subjects such as rigid/flex circuits, high speed design etc...)

I believe that the wireless mice and keyboards only transmit when an event happens, while BLE has an ongoing "pairing" traffic. TX-on-demand moves the power consumption to the reciever (which is not on battery) but it makes it impossible to tell when the keyboard has gone out of range.

They're also single-direction (apart from keyboard LEDs, which may not be present), while BLE can exchange data in both directions.