IoT- Part- 4- IoT Communication Protocol

Implementation of IoT is of no use unless or until we overcome some existing problems. As we are very much familiar with the most widely used HTTP (HyperText Transfer Protocol) and its "request and response architecture", just imagine implementing this architecture for just sending the data of one bit to someone. Below is some point we can figure out from this protocol that will create a problem for us.

• Power Consumption.
• Range
• Data-rate
• Security
• Operational Cost

Most importantly we need an addressing format for the communication between two end-points over the internet which is IP address.

Let us see what are most widely protocol that is able to overcome with this problem.

6LowPan

• 6LowPan is a combination of the latest version of  IPv6 and 'Low Power Personal Area Network' which makes enable a small device to send data over internet protocol.
• Header Compression Mechanism is made lightweight, which means IP header is compressed in data packets before it is transmitted which also reduces the consumption of bandwidth during the transmission of RTP (Real-Time Transport Protocol) or TCP (Transmission Control Protocol).
• In Header Compression Mechanism at initial (head) of each data packet, information of destination is stored (IP address).
• Range - Approx 115 meters with a single antenna. 
• Data Rates - Fixed data-rate of 250 kbit/s.
• Standards - RFC 6282, CC2538, CC1200, CC2592, CC1190.
• These standards are having freedom from frequency bandwidth and physical layer i.e 6LowPan is not something related to hardware rather just a concept such as IPv4 and IPv6 so it can be used on global multi-communication platforms such as blue-tooth, WiFi, and Ethernet.

Wireless Communication Protocols:

Bluetooth

• Wireless technology designed for data transfer between two fixed devices at a short distance using UHF (Ultra High Frequency) wavelength.
• Standard:- Bluetooth 4.2 core specification.
• Frequency:- 2.4GHz ISM (Industrial Scientific Module).
• Range:- 100 - 110m (Class 1), upto 10m (Class 2) used in headset.
• Data rate:- 2 - 3 Mbps for Smart / BLE (Bluetooth Low Energy).
• Power Consumption:- 30mA approx.
• Used in:- phones, camera, tv, speaker, etc.

Wi-Fi (Wireless Fidelity)

• Member of wireless technology family designed to provide wireless internet and network-connections at high speed.
• Standard:- 802.11n.
• Frequency:- 2.4GHz & 5GHz (Most commonly used).
• Range:- up to 50m approx.
• Data rate: 600 Mbps, 802.11-ac - 500 Mbps to 1 Gbps.
• Power Consumption: For wifi router 2 - 20 watt (6-watt average).
• Used in:- wireless router, internet access, local area wireless network, etc.

ZigBee

• A small device designed for creating own personal area network for exchanging data between many to many devices.
• Standard:- Zigbee 3.0 based on IEEE 802.15.4.
• Frequency:- 2.4GHz.
• Range:- 10-100m approx.
• Data rate: 250 Kbps.
• Power Consumption: 18mA (while receiving), 25.8-33.6mA (while transmitting).
• Used in:- M2M Communication, communication between multiple sensors, etc.

Cellular

• A communication network where the last link is wireless and data is transmitted using at least one fixed-based transmitter station specially designed for transmitting voice, text, or other types of data. This transmitter provides the services to devices that are under coverage. 
• Standard:- GSM/ GPRS/ EDGE (2G), UMTS/ HSPA (3G), LTE(4G).
• Frequency:- 900/ 1800/ 1900/ 2100 MHz.
• Range:- 6-12 km (GSM), 3-6 km (HSPA), 35-72 km (LTE).
• Data rate: 9.6 Kbps (GMS), 42 Mbps max (HSPA), Uplink 100 Mbps Download 50 Mbps (LTE).
• Power Consumption: N/A.
• Used in:- Mobile phone for voice or other content data transfer, etc.

NFC (Near Field Communication)

• NFC is a modified version of RF-ID, which is a set of the communication protocols between two electronics devices any one of them being portable (smartphone) by bringing them closer up to 4cm, mainly developed for the contactless payment transaction.
• Standard:- ISO/ IEC 18000-3.
• Frequency:- 13.56 MHz (ISM).
• Range:- up to 10 cm max.
• Data rate: 100- 420 Kbps.
• Power Consumption: 40mA while active, 3-5mA while in sleep.
• Used in:- Wireless communication in mobile phones, payment transactions, etc.

SigFox

• Developed for long-range communication between IoT devices. Specially designed for many M2M (machine to machine) applications that require low level of data transfer because using WiFi range is too short and cellular is expensive also consumes too much power.
• Uses technology called UNB (Ultra Narrow Band) designed to handle low-data-transfer speeds of 10 to 1000 bps (bits per second).
• Standard:- Sigfox.
• Frequency:- 900MHz.
• Range:- 30-50m (rural), 3-10m (urban).
• Data rate: 10-1000 bps.
• Power Consumption: 50 µwatt also having standby time of 20 years with 2.5 Ah battery.
• Used in:- Electricity meters, smart watches, etc which need to run continuously for emitting small amount of data.

LoRaWAN (Long Range Wide Area Network)

• Lorawan is a competitor of SigFox. It is a media access control (MAC) layer protocol designed for large-scale public networks with a single operator. 
• Supports large network with millions of devices, highly used in the tracking system.
• Tata group of Industries has taken license to sell LoRa chips also it is only company deploying the LoRa network in India.
• Standard:- Lora Alliance.
• Frequency:- ISM band 868 MHz & 915 MHz.
• Range:- 2-5 km in dense urban, up to 15 km in suburban areas.
• Data rate: 0.3-50 Kbps.
• Power Consumption: Have deep sleep mode technology which extends battery life upto 10 years.
• Used in:- Mobile Network Operator, Single Coordinate network, Gateway framing, up-down link acknowledgment, etc.

NB-IoT (Narrow Band - IoT)

• Radio technology device developed for Low Power Wide Area Network (LPWAN).
• This wide range of devices & services is to be connected using cellular telecommunication bands.
• Standard:- 3GPP (Generation Partnership Project).
• Frequency:- Licensed LTE.
• Range:- up to 15 km approx.
• Data rate: 100 KBps.
• Power Consumption: 74-220mA (while transmitting), 46mA (while receiving).
• Used in:- Smart metering (Gas, water), Consumer (White Goods, Tracking), Agricultural (Land, Pollution, Animal Monitoring), Smart Cities (Street lights, Parking, Waste Management), Smart Building (Alarm Building, Access Control), etc.

Summary for LoRaWan, NB-IoT & LTE

Protocol	TX Current	RX Current	Ideal Current	Sleep Current
Lorawan	24-44 mA	12 mA	1.4 mA	0.1 µA
NB-IoT	74-220 mA	46 mA	6 mA	3 µA
LTE	100-490 mA	N/A	9 mA	8 mA

In next part we will begin with implementation of ESP-01 module with arduino.