“…Due to the multi-layered architecture, vendor-specific products/applications and different hardware and protocols required for each layer, it is difficult to provide inter-operability and homogeneity in IoT. As an example, an IoT environment may have Wi-Fi, Bluetooth, 6LoWPAN or Zigbee RATs for communication; EPC, uCode, IPv6, URIs for identification; MQTT, CoAP, AMQP, Websocket for messaging; Physical Web, mDNS, DNS-SD for discovery; JSON-LD, Web Thing Model for semantics; TR-069, OMA-DM for device management, etc [29].…”