The Internet of Things and particularly energy constraint object revealed these last years some radio frequencies technologies which allow to realize wireless transmissions at long range and with low energy. This change of paradigm makes tip over the problems of multi-hop networks to multi-channel MAC networks. The LoRaTM technology arises from this sphere of influence by using the spread spectrum to reach the expected performances. This physical layer is very original compared with the physical layers used for a long time with the IEEE 802.15.4 standard. This article highlights the specificities of the LoRaTM physical layer to design new MAC layers for the ad hoc Internet of Things.