In this paper, we review advanced synchronization techniques for the internet of things. Our study can be directly applied to the single-carrier IEEE 802.15.4 and IEEE 802.15.6 standards. In particular we display the advantages of using a Code-Aided approach and a Bayesian packet-oriented approach. The performances of several phase-locked loop techniques are compared to different Cramer Rao Bounds so that one can see the advantage of respectively the Bayesian approach compared to the on-line approach and of the Code Aided technique compared to the Non Data Aided/ Data Aided approach.