6LoWPAN protocol stack

To enable 6LoWPAN on a form of communication media such as 802.15.4 there is a set of recommended features necessary to support an IP protocol. These features include framing, unicast transmission, and addressing. As shown in the following figure, the physical layer is responsible for receiving and converting data bits over the air. For this example, the link layer we speak to is IEEE 802.15.4. On top of the physical layer is the data link layer, responsible for detecting and correcting errors on the physical link. Detailed information on the physical and data link layer of 802.15.4 are covered earlier in this chapter. Here is the comparison between the 6LoWPAN stack and the OSI model:

By enabling IP traffic at a sensor level, the relationship between the device and the gateway would use some form of application layer to convert data from the non-IP protocol to and IP-protocol. Bluetooth, Zigbee, and Z-Wave all have some form of conversion from their base protocol to something that can communicate over IP (if the intent is to route the data). The edge routers forward datagrams at a network layer. Because of this, the router does not need to maintain application state. If an application protocol changes, a 6LoWPAN gateway doesn't care. If an application protocol changes for one of the non-IP protocols, the gateway will need to change its application logic as well. 6LoWPAN provides an adaptation layer within layer three (network layer) and on top of layer two (data link layer). This adaptation layer is defined by the IETF.