Wireless Protocols for IoT Applications

By: J.R.Rana (jitendrarana@jnec.ac.in)
Date: 19^th April 2021

The corona pandemic conditions have changed the entire world. Social distancing, work from home, home tutoring, webinars, virtual classrooms are new generation words. In pandemic disease isolation is the only key precaution as of today. In isolation or lock down conditions many activities such as scanning of the passengers at airport, railway station, bus stand, shopping malls, multiplex, etc. is necessary for stopping the spread of virus. Wireless sensors network can be used for scanning at public places, getting data of infected persons, analysis of data, finding locality of infected person, providing health care, hospitalization to the patient can be executed using IoT Applications.

The implementation of any kind of automation is done by using IoT. In system IoT, Sensor network may be used along with wireless protocol modules which will act as a trans receiver. The collected data can be intimated to the health care department, hospitals, police station etc. for necessary action. As the complete system works on wireless, principle bulk data can be effectively collected without making people to wait for scanning in queue. Thermal scanner, thermocouples, temperature measurement guns, coughing detection with microphone all these sensors can be used to identify the symptoms of the disease; the camera can be used to capture the image of infected person only for record and tracking purpose. The scanning process can be implemented using tunnel or zone of scanning area. Recorded data can be processed using wireless sensor network system. The control room will collect and share the data to the necessary regulatory departments. The future system will help in identification of sick persons effortlessly without affecting the health of medical health workers. It will help to identify the seek person, keep record of the persons, taking necessary administrative and medical action for the person, maintaining social distancing while scanning and may help in reducing the spread of virus.

In developing medical support system using electronic sensors, latest wireless technologies will play an important role. If we want to develop a system for group/mass temperature measurement for example, then we need a trans-receiver module which can send and receive data bits. The block diagram represented here is divided into two parts. The transmitter blocks include Power Supply, IR sensor array, Camera and Wireless protocol unit. The scanning zone may have the facility to install the sensor at appropriate distance for effective scanning of people. The receiver unit will have power supply, control unit, data processing block and control signal unit for different authorities. The collected information will be continuously sent to control unit. The scanning of data will also take place at the same time. If the temperature detected of person fall under the sensitive category, then immediately control unit will send the signal for image capturing to the camera. The information will be shared to different authorities as and when required.

TEMPERATURE SENSOR
The temperature sensing can be done using thermometer, thermocouples, temperature infrared gun or a recent camera-based IR array-based sensor called MLX90640 IR array sensor. The sensor is a calibrated 32x24 pixels thermal IR array. It is developed as per industry standard 4-lead TO39 package which also has digital interface. The sensor contains 768 FIR pixels. The sensor can represent dynamic thermal images. It is used for the temperature range between -40℃ to 300℃.

The features of the MLX90640 IR array sensor are,

• It is a small size sensor available at low cost.
• The sensor can be integrated easily with system.
• The sensor is developed with Industry standard 4.0
• The sensor is well calibrated at manufacturing end.
• Operating temperature is -40℃ to 300℃.
• It has I2C compatible digital interface.
• The sensor has programmable refresh rate 0.5Hz to 64Hz.
• It operates at 3.3V supply voltage 23mA Current.

• Highly accurate non-contact temperature sensing.
• It is used for presence detection, localization of person with temperature sensing element for smart building air conditioning.
• It finds application as a thermal comfort sensor in automobile Air Conditioning system.
• Sensor is used to perform industrial temperature control of moving parts.
• Visual IR thermometers, Intrusion / Movement detection.

WIRELESS PROTOCOLS
The second thing which we need to avoid contact of infected person to a system is a wireless protocol which will send or receive information using contactless communication. There are many wireless protocols available for executing such tasks. Few of the wireless protocol even work on low power supply of a battery for years. The sensors should have features like, a long range of data transmission, low power consumption of device, data security, efficiency of device, accuracy, and precision of data transmission etc. Here are few wireless protocols which can be used for development of IoT Applications.

1. LoRa WAN
The SEMTECH Company manufactured wireless protocol SX1272 LoRa Transceiver module has following features,

• Programmable bit rate of 300kbps.
• Operating temperature range -40 to +85 degree.
• Frequency Range of 860-1020MHz.
• Spreading factor 6-12.
• Bandwidth 125-500KHz.
• Sensitivity is 117 to -137dBm.
• MLQP 28 pins lead package.
• Supply voltage 1.8V to 3.7V.
• Integrated synthesizer with resolution of 61Hz.
• LoRa works as a Modem.

2. Z Wave
The silicon lab manufactured wireless protocol Z wave 700 series module has following features,

• Programmable bit rate up to 100kbps.
• Operating temperature range -40 to +85 degree.
• Current required from9.8mA to 13.3mA
• Frequency range of 865.-925.3MHz
• Sensitivity 97.5 to 97.9dBm.
• Supply voltage from 1.8V to 3.8V.
• Low power mode.
• It is a 64 pin IC package.

3. NFC (Near Field communication)
The near filed communication is a contact less communication which has following features,

4. Bluetooth
Well known wireless protocol, which is used for mobile file transfer, connecting audio devices, headset etc has following features,

• Bluetooth is IEEE 802.15.1 wireless protocol.
• Operating frequency is 2.400GHz to 2.485GHz.
• Low Power consumption protocol.
• Range limitation up to100 meters.
• Data transfer rate up to 24Mbps.
• Useful for low range data transfer.

5. Wi-Fi
Another well-known wireless protocol for communication is Wi-Fi has following features,

• Wi-Fi is IEEE 802.11 wireless protocol.
• Operating frequency 2.4GHz to 5.0GHz
• High power consumption protocol.
• Limited range up to 150 meters in radius.
• Data transfer rate 3.46Gbps.
• Useful for low range data transfer.
• Useful for wide range data transfer.

6. ZigBee
ZigBee specifically used for home automation has following features,

• ZigBee IEEE 802.15.4 wireless protocol.
• Operating frequency 2.4GHz.
• Low power consumption protocol.
• Range up to 1500 meters in line of sight.
• Data transfer rate 1Mbps.
• Useful for long range data transfer.

APPLICATIONS
Depending upon the applications and desired features we can select any wireless protocol mentioned above. The wireless protocols can be used for IoT based smart city applications for home automation, industry automation as well as pandemic conditions,

1. Home Automation
2. Industry Automation.
3. Patient monitoring.
4. Screening of patient.
5. Surveillance.
6. Public place safety.
7. Food and drugs supply.

(Author is Assistant Professor from Department of Electrical Engineering of Jawaharlal Nehru Engineering College which is constituent college of MGM University, Aurangabad.)