**4.2 Data transport**

The MQTT employs a connection oriented communication given by TCP and the CoAP uses UDP. The TCP protocol uses more data to exchange messages between the client and the server in relation to UDP, thus having a higher. Both the MQTT, like CoAP are designed for limited networks like 6LoWPAN (IPv6 over low-power personal area networks). According to [9], if TCP or UDP are not needed, an alternative is to choose the MQTT-SN over 6LoWPAN (IPv6 over low power personal area wireless networks) 4 or even ZigBee, avoiding the complexity of the complete TCP/IP stack. The CoAP It is also designed for limited networks such as 6LoWPAN, in order to maintain short message overload, thus limiting the need for fragmentation that causes significant reduction in the probability of packet delivery.

Regarding the message format, both MQTT and CoAP are suitable to be used in limited bands. Both have a binary message format, different from protocols like AMQP (Advanced Message Queuing Protocol), which uses uses XML formatted messages, in this case requiring the use of more interpreters complex, increasing the hardware requirement.
