6LoWPAN

Introduction
6LowPAN ( IPv6 over Low power Personal Area Networks) has been developped to define the IPv6 adaptation and the way to transport the IP datagramms on IEEE 802.15.4 based networks. The main function is the encapsulation and the header compression. The task is facilitate because there is no impredictable field (for exemple the cheksum or the id).

Mode of operation
The 6LoWPAN can work under 2 network achitecture.

Route-over mode
Most of the elements are routers. the routing will be done on the entire adresses (128 bits). a routing table (build with a protocol as RPL or LOADng) will associate to each adress a next "jump" to a next neighboor device in range. In this mode, the adress can be anything because (with different prefix), as they are in the routing table. Each router must decompress the packet to build the destination adress, find the next jump then re-compress the packet to send it to the right device.

Mesh-under mode
This mode hide on the third level the data about the sub-network. The adressing rules make than every devices use the same prefix, the compression is made when the data is sent and the decompression when it is received. The intermediate routers will process with the compressed header. This is why 6LoWPAN include some more headers allowing the data diffusion toward all the connected device, a header indicating the source and the destination of the packet.

Open IP standard

 * Open Standards inclding TCP, UDP, HTTP, COAP, MQTT and websockets
 * End-to-end IP adressable nodes
 * No gateway needed. A router connects the 6LowPAN network to IP

Mesh routing

 * One-to-many and many-to-one routing
 * Robust and scalable
 * Self-healing
 * Mesh routers can route data destined to others, while host are able to sleep for long periods of time.

Multiple PHY support

 * Freedom of frequency band and physical layer
 * Us across multiple communication platforms (i.e. Ethernet / Wi-Fi® / 802.15.4 / Sub-1GHz ISM)
 * Interoperability at the IP level.