MAC Layer
Daniel Chew · 2018
This chapter focuses on the background theory necessary to understand the media access control (MAC) layers for wireless Internet of things (IoT) protocols. It relates those theories to actual wireless IoT examples. What specific functions are encapsulated in the MAC layer varies from protocol to protocol. These functions include, but are not limited to, multiple access techniques, the synchronization of spread spectrum, and error correction. These error-checking functions may involve forward error correction (FEC) and cyclic redundancy checks (CRC). Spectrum planning avoids collisions and contention in the spectrum between multiple services by allocating locations and frequencies to those services. A national regulatory authority allocates licenses to services for the use of portions of the spectrum. When developing an IoT application, the wireless IoT developer must choose a method to manage spectrum access. Spread-spectrum techniques can provide methods of multiple access.