The Government of India is keen to adopt Machine-to-Machine (M2M) communications and therefore released an M2M roadmap last year to foster large scale deployment. India is a strong advocate of IPv6 and compliance to IPv6 is mandatory in today’s scenario. In addition, the Telecommunication Engineering Centre (TEC) released technical reports on M2M communications in sectors such as Power, Transport, Health, Safety & Surveillance and Gateway & Architecture the same day.
The Government is in the process of connecting 250,000 gram panchayats (A gram panchayat is the cornerstone of a local selfgovernment organisation in India of the Panchayati raj system at the village or small town level, and has a Sarpanch as its elected head.) on an optical fibre network for E-Governance, E-Learning, E-Health etc. In November 2014, two new schemes were launched, namely the Integrated Power Development Scheme (IPDS) and Deen Dayal Upadhyaya Gram Jyoti Yojana (DDUGJY) which, apart from other objectives, envisage the extension of NOFN to 33KV and above substations for providing a backbone network for smart grid applications.
The first attempt to inject communications into the power sector was the implementation of Automated Meter Reading (AMR) by distribution companies (DISCOMs) and SCADA/EMS by transmission companies (TRANSCOs). Now, many DISCOMs are also in the process of commissioning SCADA/DMS and many have already done so.Smart grid communications come under the purview of M2M communications wherein machines/devices/sensors communicate amongst themselves and also with the control centre/server for fulfilling the envisaged purpose.
How far we have come
After over a century of generating electricity centrally and building massive electric grids, the focus is now on decentralised generation and microgrids. This is causing the traditional boundaries
between generation, transmission and distribution to disappear. Consumers are becoming ‘prosumers’ by generatingelectricity locally and having an option of feeding it back to the grid. Hence, there is already a debate on whether to invest in decentralised generation plus storage plus local distribution or centralised generation plus transmission plus distribution.
The traditional electricity networks that were designed for unidirectional flow of electricity, revenue and information are on the threshold of a paradigm shift which will enable bidirectional flow of these elements. Before the advent of smart grids, communication networks were used tomonitor and control the power flow only up to the medium voltage along with low voltage substations using Supervisory Control and Data Acquisition (SCADA)/ Energy Management Systems (EMS). Smart grids will enable monitoring and controlling of the power flow in the low voltage grid
up to the end consumers using SCADA/ Distribution Management Systems (DMS). Advanced Metering Infrastructure (AMI) would enable remote reading, remote connection/disconnection, remote load control (based upon time of day or time of use prices), and early detection of outages using two-way communications.
Wide Area Monitoring, Protection andControl (WAMPAC) would offer a high degree of visibility in the electricity grid by synchronously measuring the phase of the current and voltage vectors for monitoring, controlling and protection of the high voltage grid. Electric vehicles would not only offer a cleaner mode of transport but also act as virtual power plants to reduce the demand and supply gap. Secure, reliable, scalable, interoperable and cost effective communication networks would be required for the above mentioned domains. It is believed that the grid willsoon emerge as a ‘Grid of Things’ just like the Internet has evolved as the ‘Internet of Things’. With billions of connected devices in a smart grid, cyber security and data analytics would also be vital for seamless operation.
Characteristics of M2M communications for the power sector
Different applications in the power sector have different bandwidth and latency requirements. For example, smart metering requires less bandwidth and has no severe latency conditions whereas substation automation requires higher bandwidth and improved latency. Apart from availability, reliability of the communication networks has become a major concern.
Using standards-based technologies will ensure a high degree of scalability and interoperability. The choice of operating frequency is vital for deciding the power consumption of the devices and range of the communications network. Having a long technology life-cycle, compliance to regulations and total cost of ownership are other key characteristics. Moreover, all communication technologies must possess the necessary measures to be resilient to cyber attacks.
Potential M2M Communication Solutions
A number of communication technologies are present today. For the last mile network, Neighbourhood Area Network (NAN), Field Area Network (FAN), 6LoWPAN-based RF mesh, ZigBee, Wi-Fi,
PLC, Ethernet and serial interfaces are popular candidates. For the Home Area Network (HAN), 6LoWPAN-based RF mesh, ZigBee, Wi-Fi, Bluetooth, Z-Wave, NFC, PLC, Ethernet, and serial interfaces are expected to be commonly used.
Depending upon the requirements, cellular communications, satellite communications, LPWA, Long Wave Radio, TVWS, Optical Fibre, Ethernet, PLC, DSL, Private Microwave Radio Links (both, P2P
and P2MP) could be used for the backhaul/Wide Area Network (WAN) and Backbonenetworks.
The selection of a technology will depend on the envisaged application. For mission critical applications (such as SCADA/DMS,SCADA/EMS, Substation Automation etc.),security, reliability and latency will be the key criteria for deciding a communication technology. Cost will be of least priority. For non-critical applications (such as AMI, electric vehicles etc.), cost will be the decisive factor.
Current spectrum scenario
At the present time, 433-434 MHz and 865-867 MHz are the un-licensed wireless frequency bands that could be used for M2M communications in India. To cater to the billions of devices that would be deployed in smart grids and smart cities in India, we may need to allocate additional spectrum for low power RF devices. Globally, countries have allocated a much wider band in order to accommodate such devices. The Department of Telecommunications is planning to allocate frequency bands for Power Line Carrier (PLC) communications as well.
Smart grids are set to transform the way electricity networks operate by injecting communications, automation and IT into the traditional grid. The power sector is already reaping the rewards of using M2M communications. Adopting IPv6 will enhance the performance of networks and also provide an additional layer of security via the IPSec protocol suite. The smart grid will be a heterogeneous network comprising multiple communication technologies, the selection of which will depend on the envisaged applications; and whether they are considered mission critical functions or non-critical applications.