Technical Articles
The task of Automated metering in large localities wherein meters are spread out is quite complex in terms of wiring as well as the architecture making it financially unviable. Wireless metering solution would be a way forward to simplify this problem.
Many existing deployed networks utilize a wireless mesh network architecture. In a mesh network, the individual end-nodes forward the information of other nodes to increase the communication range and cell size of the network. While this increases range, it also adds complexity, reduces network capacity.
LoRa technology is now being touted as the DNA of IoT with its simple long-range star architecture that makes the most sense for preserving battery lifetime when long-range connectivity can be achieved.
LoRa stands for Long Range. The advantage of LoRa is in the technology’s long-range capability. LoRa service providers can setup a public network with large single gateway or base station that can cover hundreds of square kilometers. Range highly depends on the environment or obstructions in each location. Also, LoRa operates on license free 865 – 867 MHz ISM band in India which means there is no spectrum fee on this frequency range.
LoRaWAN defines the communication protocol and system architecture for the network while the LoRa physical layer enables the long-range communication link.
LoRaWAN networks are laid out in a star topology in which gateways relay messages between end-devices and a central network server at the backend. Communication between end-devices and gateways is spread out on different frequency channels and data rates. The selection of the data rate is a trade-off between communication range and message duration, communications with different data rates do not interfere with each other. LoRa data rates range from 0.3 kbps to 50 kbps.
The image identifies LoRa and LoRaWAN spaces. For metering application, Class C offers lowest latency among the classes thereby ensuring highest reliability of data receptivity.
LoRa network allows the end-devices to individually use any of the possible data rates. This feature is used by the LoRaWAN to adapt and optimize the data rate of static end-devices. This is referred to as Adaptive Data Rate (ADR) and when this is enabled the network will be optimized to use the fastest data rate possible.
A typical network architecture for IoT requirements are shown below.
In a LoRaWAN network for metering solution nodes are associated with a specific gateway. Each gateway will forward the received packet from the end-node to the network server. The intelligence and complexity are pushed to the network server, which manages the network and will filter redundant received packets, perform security checks, schedule acknowledgments through the gateway, and perform adaptive data rate, etc.
Following components will form part of the solution:
These are whole current 10/60A, 20/80A or CT operated meters in Class 1 accuracy with V, A, PF, W, VA, Wh parameters. These dual source meters have dual energy registers - one for EB Wh and another DG Wh. In some cases where water or gas meters are required to be integrated, it is possible with a variant of this meter with 2DI.
The outdoor gateways can be configured with input on LoRaWAN and output as Ethernet or GPRS (4G). These gateways have an antenna which should be positioned to get highest signal receptivity. It can easily work in a radial range of 1 km without Line of Sight (LoS).
If GPRS route is used to connect to Head end system, then public static ip would be required.
Proper network optimisation by proper location of gateways and number of gateways can help in overall data acquisition from end nodes.
Typical devices that can be connected on one gateway are as follows:
* The final number of nodes wrt data interval will also depend upon the terrain in which the meters are installed along with the interferences.
The LoRaWAN Network Server provides the management of gateways and endpoints, authentication and authorization of endpoints, network encryption and decryption, data routing, adapting data rates, eliminating duplicate packets, and interfacing with applications.
The solution can be configured using two possible types:
1. Public Network Server
In India, TATA Communications leads in providing LoRaWAN access as service provider. The monthly billing cost incurred would depend upon the data packets sent and received.
2. Private Network server
If the application is local based, then a private network server can be used. The limitation for a private network is connection of maximum 5 gateways. There is no restriction for data transfer as there are no monthly rentals for data transfers.
UPS is always required for the network server as frequent power failures may lead the internal OS to crash.
The application server would include the broker services that oversees packet deliveries, Middle ware services and application software - SmartComm EMS. The application server collects data from network server in decrypted format. The application server and network server would be installed in the same location through Ethernet for higher security. This server runs the application software i.e SmartComm EMS that will offer data to customer in user understandable format.
SmartComm EMS is Energy Management software with a host of benefits for the user. It contains dashboard with trends and analytics showing energy consumption to user at the click of mouse. Dashboard contains bar graph energy consumption representation on hourly basis, monthly basis, yearly basis, TOD basis as well as yoy comparison. More details on this can be accessed at www.lntebg.com/ems
Two methods are available to achieve end to end solution.
Configuration of the meters i.e linking a set or cluster of meters to a specific gateway is done by scanning the barcode on these meters using LoRa config app. This ensures communication is done only with the gateways and meters that are linked. Maximum of 5 such gateways can be connected to the network server. The average distance is upto 1 kms without Line of Sight.
In future, for the same cluster of gateways and meters combination, if the number of meters to be installed increase then data interval period can be increased so that more meters can be brought under the ambit ensuring scalability of the system and architecture.
1. Private network architecture on Ethernet
2. Private Network architecture on GPRS
LoRaWAN is becoming one of the de-facto communication technology for the IoT world. Using this technology, existing constraints of wide area local wireless metering can be managed effectively using wireless metering solutions from L&T Electrical & Automation.
References:
[1] LoRaWAN™ 1.0.3 Specification, LoRa Alliance
[2] www.lora-alliance.org
Divyesh B. Vaghasiya,
Senior Product Management and Marketing professionalDivyesh B. Vaghasiya is a Senior Product Management and Marketing professional focused on Industrial IoT, Energy Management, and Smart Technologies. With 13+ years of experience in the electrical and automation industry, he combines deep technical knowledge with strategic business thinking. He shares perspectives on emerging technologies, product management, sustainability, and digital transformation, helping businesses navigate the evolving energy landscape.
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