IoT_Lecture-4
Name 2 techniques which help to reduce energy usage of wireless nodes.
- IPv6 over Low Power Wireless Personal Area Networks (6LoWPAN) - Lowering transmission rate
For what application areas are the design of 6TiSCH targeting?
Industrial applications.
We can use both MQTT and CoAP for data exchange, what are the characteristics of these protocols? What are the pros and cons of these two protocols?
MQTT: - Use TCP - Guarantees the reliability of packet transmission - When the network environment is poor, it will retransmit the packet; this causes more network congestion CoAP: - Use UDP - The mechanism is easier and tolerate at packet loss - Data transmission is not reliable
Mention two reasons why the RESTful architecture is beneficial in the context of IoT.
REST allows data to flow over internet protocols and to delegate and manage authorization.
What is a RESTful protocol?
RESTful is a software architectural style that defines a set of constraints to be used for creating Web services. Web services that conform to the REST architectural style, termed RESTful Web services (RWS), provide interoperability between computer systems on the Internet. RESTful Web services allow the requesting systems to access and manipulate textual representations of Web resources by using a uniform and predefined set of stateless operations.
To assess various wireless technologies, what kind of factors/parameters can we use?
Range, data rate, power consumption, security
Wireless Local Area Networks (WLAN): Bluetooth
Range: 100-400m Data rate: <25Mbps Power consumption: Low, 1W
WLAN: Thread
Range: 100m Data rate: 250 kbps Power consumption: Low
WLAN: ZigBee
Range: 100m Data rate: 250 kbps Power consumption: Low
LPWAN LTE-M
Range: 11 km Data rate: 1 Mbps
LPWAN NB-IoT
Range: 15 km Data rate: 250 kbps
Based on these factors/parameters, what are the characteristics of the wireless communication technologies discussed in class: (LoRA,SigFox, NB-IoT,LTE-M, WiFi, Zwave, ZigBee.Thread, Bluetooth, BLE, IEEE 802.15.4 TSCH). Low-power wide-area network (LPWAN): LoRa
Range: 15 km Data rate: 50 kbps Lower power consumption than NB-IoT and LTE-M
WLAN: Z-Wave
Range: 30m Data rate: 40 kbps Power consumption: Low
LPWAN SigFox
Range: 50 km Data rate: 1 kbps
WLAN: Wi-Fi
Range: 50m Data rate: 600 Mbps; ax: 10 Gbps Power consumption: High
WLAN: BLE (Bluetooth Low Energy)
Range: > 100m Data rate: <20 Mbps Power consumption: Low, 0.01 - 0.5 W
Mention two methods that are used in 6LoWPAN to reduce the message (header) size.
Segmentation and compression
What protocols are building up the 6TiSCH stack?
The IETF 6TiSCH protocol stack, composed of IEEE 802.15.4, IETF 6P, 6LoWPAN, RPL and CoAP.
What kind of overhead will you experience for each of the protocols above?
The MQTT protocol provides a header of 2 bytes. While TCP has an overhead size of 20 bytes, the IP overhead depends on what version of the protocol used v4 or v6 which is 20 bytes or 40 bytes respectively and the Ethernet protocol takes 14 bytes.
How many bits will need to be transported over the air using IEEE 802.11 (WiFi), if MQTT and IPv6 is used.
The MQTT protocol uses 2 bytes while ipv6 has 40 bytes of header size and WiFi uses 2 bytes overhead. Meaning in total 44 bytes (+ whatever package size is sent)
Describe how a sample can be packaged and sent to the cloud (describe each of the protocols involved)?
The sample would first be packaged in some format like JSON, then use the mqtt protocol. Then use TCP in order to connect to the google cloud server. Then use the IP to find the right place on the internet. Then last if connected via ethernet it also uses the ethernet protocol to encapsulate the package.
