How does communication protocols work?

Wired Communication Protocol (major) :

UART – Universal Asynchronous Receiver & Transmitter

• Very Basic Communication Protocol.

• Full Duplex.

• Size of the data frame is limited to only 9 bits.

• Parity bit to allow for error checking.

• Cannot use multiple master systems and slaves.

• Baud rates of each UART must be within 10% of each other to prevent data loss.

• Low Speed.

• Less Distance.

• Cheap Cost.

SPI – Serial Peripheral Interface

• High Speed comparably UART.

• Full Duplex.

I2C – Inter Integrated Circuit

• Two Lines used. (SDA and SCL)

• SDA means Serial Data Line and SCL means Serial Clock Line.

• High Speed.

• Half Duplex.

Major used wireless communication protocols in IoT :


• LPWAN is a type of wide area network which connects devices over large area and allows long range communication at a lower bit rate, low cost and greater power efficiency.

• LPWAN supports a large number of devices over wide area in comparison to cellular services. Examples of LPWAN are NB-IoT, LoRa, SigFox etc

Why Zigbee?

• I am sure that you are familiar with short-range wireless networking technologies like Wi-Fi and Bluetooth which are used to connect devices. These technologies are fairly mainstream today and are used in specific use cases.

• For example, if you want to stream audio you likely to use Bluetooth likewise, if you are streaming video or large files, you are likely to use Wi-Fi.

• But let us think of a use case where we have to connect a large number of battery operated devices.

• Is it ok to operate using Wi-Fi or Bluetooth? The answer is clearly NO. Because Wi-Fi consumes a lot of power and is therefore not ideal for battery operated devices. Most of the Wi-Fi devices like your mobile phones or your laptop are usually changed on a daily basis.

• Then what about Bluetooth? You  may say well. Bluetooth consumes less power than Wi-Fi so would that not be ideal for our use case? But you can connect only a limited number of devices to a Bluetooth network and therefore Bluetooth is not ideal for our use case as well.

• So, what could be a better solution to connect a large number of battery operated devices? ZigBee.


• Zigbee, like Wi-Fi and Bluetooth, is a short-range wireless protocol

• Long battery life.

• Low Cost.

Data Rate: 250kbps.

Range: 10 – 20 meters.(indoors)

Security: 128bit AES algorithm to encrypt and authenticate.

• In fact the Swedish city Gothenburg is a giant zigbee network where over 250000 homes are connected together for the purpose of remote energy metering.


We need a wireless network that consumes very low power, but also operates over distances larger than those of say, Wi-Fi. Is such a network even possible? Yes, That one is LoRa.


• LoRa – Long Range communication.

• Introduced by SEMTEC.

• Technology: Radio Modulation.

• Aim: Data transfer in low power and long range.

• Distance: 15 to 20km.

• Cellular based communication.

• LoRa Bit rate is quite Low. 10kb per second.


• The IoT revolution is yet to reach its peak, but SigFox just announced that they aim for 1 billion devices connected to its network by 2023. so what is this technology? SigFox.

•This technology remotely interfaces battery operated devices and sensors to the internet.

• SigFox uses less power and is effective over long distances compared to connection protocols such as Bluetooth and Wi-Fi, which work best in the short range and use more power.

• Present in 72 countries & Regions.

• 2020 Range Covered: 5.7km.

• 0 to 140 message sent per device per day.

• Data Range: 100 to 600bps.

SigFox Work Flow:

• Objects — Base Station — SigFox Cloud — Internet, API and Call-backs.


• NB-IoT or Narrow Band IoT is a standards based LPWAN that can be rolled out on top of the existing cellular network infrastructure.

• Cellular networks today allow us to transfer large volume of data at high speeds with low latency over very large distances.

• That trade off is that cellular devices consume a lot of power and are relatively expensive.

• No Gateway.

• NB-IoT operates via cellular carrier networks in one of the following 3 ways.

  1. GSM Carrier.

  2. LTE Channel.

  3. Independent.

• IoT through cellular network.

• Data Rate: 20kbps – 5Mbps.

• Transmission Range: <35km.

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