- Rian Sullings
LPWAN & Smart Water Metering
The purpose of this article is to share an understanding of new wireless technologies that are opening new opportunities for smart water metering. It will also give an overview of these technologies and how they compare to one another in terms of technical capabilities and business models.
What is LPWAN?
Low Power Wide Area Network (LPWAN) is a category of wireless communication technologies. In the past few years new LPWAN technologies have emerged to fill a gap in the market where there is a need to send small messages over long distances with low power consumption and low cost. Many of these technologies cater to use cases beyond just water metering. This addresses the rapidly growing requirements of the Internet of Things (IoT) which is the concept of enabling internet connectivity for a wide range of ‘things’ from smart water meters to parking sensors, weather stations, GPS trackers, and countless other objects. The purpose of IoT is to deliver additional value from physical devices and objects through data collection, analytics, machine learning, and driving insights into usage behaviours. Smart water metering is a perfect example of IoT where it enables new labour, economic, and sustainability efficiencies.
Similar to other forms of wireless networks, LPWANs consist of devices with compatible radio modules to send and receive messages, radio receivers similar to those of mobile phone networks although often much more compact, and server infrastructure to manage and distribute data.
Unlike 3G, 4G, and WiFi which are designed to carry large volumes of data such as audio and video with great speed, LPWAN technologies cater to the efficient wireless delivery of relatively small packets of data such as meter readings and other sensor measurements.
All wireless technologies must strike a balance between 3 parameters: 1) Range and penetration: how far coverage extends and how well it penetrate through walls and underground pits 2) Power consumption: how much energy is required to send messages 3) Data-rate: the speed that data can be transferred and therefor the size of the messages which can be sent
LPWAN technologies achieve long range, signal penetration, and low power consumption but offer only relatively low data-rates. Cost is of course another factor and LPWANs address this through lower connectivity pricing and simpler, lower cost radio components than other wireless technologies.
LPWAN networks typically achieve 2 to 10 kilometres of maximum range in urban environments and further in rural areas, depending on geography, obstructions, positioning, and other factors such as interference, noise, and traffic on the spectrum.
One of the highest power consuming tasks of smart water meters is the wireless transmission of data. There are of course many factors which contribute to power consumption from one scenario to another but it is generally around 0.05mAh to 0.2mAh per transmission over common LPWAN networks. For reference, high quality AA batteries have around 1,200mAh of capacity which means that a typical LPWAN device is capable of sending around 6,000 to 24,000 messages on a single AA battery. Of course the actual power consumption of any device is dependent on a range of factors such as the design, network performance, and local constraints.
In terms of data-rate, LPWANs are relatively slow when compared to other common wireless technologies. Data-rates are generally in the area of 300 bits to 50 kilobits per second. This may seem slow when compared to the 20 to 40 megabits per second achieved by 4G for applications such as live video streaming but it is more than sufficient for sending small packet sizes such as water meter readings. By utilising lower data-rates, LPWAN technologies are able to achieve longer range and lower power consumption.
Smart Water Metering Requirements
There are many different technologies within in the category of LPWAN and it can be challenging to understand which ones to focus on. The use cases of smart water metering have certain requirements which can be used to determine which LPWANs are best suited for each unique project. While it is easy to get caught up in technical and commercial details, these requirements can be simplified down to just five basic truths.
Technical Capability: Smart water metering solutions must be capable of delivering value to utilities, users, and other stakeholders. This includes delivering the data required to gain insights into water use such as meter readings. Low power consumption must be ensured to achieve 8 to 10 or even more years of battery life from devices. In some cases more advanced functionality such as additional sensors and configuration changes over the air may be required.
Vendor Agnostic: Solutions must cater to multiple vendors to avoid scenarios where the utility or user is required to invest in implementing a single-vendor solution that cannot readily be used by other device manufacturers, network operators, or software applications. Any infrastructure investment should support a large ecosystem of partners beyond smart water metering. This brings economies of scale and improves the cost-benefit of the network. Large ecosystems also drive faster development and problem solving through global communities.
Reliable and Secure: Any system that is intended to operate for extended periods of time must be sufficiently reliable such that they do not require significant amounts of labour or unexpected costs to ensure proper operation. Solutions must be secure such that privacy of data is not breached, and operations or property cannot be effected or result additional costs to repair due to unwarranted interference or tampering.
Scalability: Solution must be readily scalable to cater for additional geographic coverage in both urban and rural areas, quantities of devices, quantities of users, and the range of applications and stakeholders which may utilise the data from the system now and into the future.
Capex and Opex: The solution must be economically viable to establish and to continue to operate. Water utilities face challenges in making business cases for smart water metering and the total cost of the solution is a key factor in determining its viability.
Overview of Key LPWAN Technologies
There are many LPWAN solutions which address some or most of the smart water metering requirements and some of these are great solutions in their own rights. In recent years however, three key technologies have emerged to stand out from the pack as truly fit for purpose while opening new opportunities. These are Sigfox, LoRaWAN, and NB-IoT. Each of these are unique in many aspects but all three address the key requirements of smart water metering, as well as readily enabling other use cases for water utilities, facilities, IoT, and smart cities.
All three technologies:
Offer sufficient capabilities to address the vast majority of smart water metering functionality and technical requirements
Are vendor agnostic, cater to a wide range of vendors for hardware, software and services, and do not require significant investments that lock users into single-vendor solutions
Provide the security required to ensure privacy of data and are resilient to tampering and malicious attacks
Are scalable in terms of the number of devices, users, vendors, software and services, and the areas of coverage
Can be established, maintained, and operated at low price points, due in part to their global scale
Sigfox is a global wireless communication provider and the name of the wireless network solution that it offers. Sigfox was founded as a company in France in 2009 and continues to rapidly roll out its wireless network across the world. As of March 2018, Sigfox operates in 45 countries and provides coverage to 803 million people across 3.8 million square kilometres.
In many countries Sigfox has partners which function as the local Sigfox Operator (SO). In Australia, the local SO is Thinxtra who have rolled out network coverage to approximately 80% of the Australian population as well operating networks in New Zealand and Hong Kong. From 2017 to date the Australian government has committed $10 million to Thinxtra through the Clean Energy Finance Corporation, effectively making the Australian government a stakeholder in the network.
Sigfox currently has a major advantage over other LPWAN technologies in Australia in that it has the lowest barriers to entry. The network is available in all major cities including many regional centres, radio modules are standardised and kept at absolute minimum prices, devices connect to networks automatically without users having to go through complicated registration processes, data is accessible from the network server by an API and through a range of other existing interfaces, and where coverage is not available there are solutions to establish new basestations including free deployment in exchange for sites such as rooftops or water reservoirs.
The Sigfox ecosystem is highly mature compared to other LPWANs and includes a range of radio module manufacturers, devices, integrated software, system integrators, and consultants. There are currently over 400 different devices commercially available for use on Sigfox networks from GPS trackers for livestock to defibrillators, and a wide range of sensors for water utilities.
A number of projects have already been undertaken with water utilities in Australia such as smart water metering and sewer choke alerting. Results have been very promising with many utilities looking to adopt or scale up the use Sigfox for metering and remote sensing applications.
One important consideration with Sigfox is that the protocol permits the smallest packet sizes of the three key networks. These packets are a maximum of 26 bytes including a 14 byte encrypted header containing device ID and other management and security features and up to 12 bytes for the payload. The implication of this is that very few meter readings can be sent in a single packet. Device designers must utilise these 12 bytes wisely in order to achieve more advanced functionality.
Due in part to its simplicity, Sigfox is one of the lowest power consuming of the three key technologies and battery life is not effected by signal quality or network coverage. Each transmission consumes practically the same amount of power which makes it much easier to manage the battery life of large fleets of water meters.
Sigfox is one of the simplest, most mature, and lowest cost LPWAN options available. While it has constraints for some applications such as small packet size, it is perfectly suited for most IoT use cases including simple and low cost smart water metering. I have written a detailed paper on Sigfox and Smart Water Metering and will be sharing detailed papers on other technologies in the near future.
The name LoRaWAN comes from Long Range Wide Area Network. LoRaWAN covers everything required between a physical device such as a smart water meter and the cloud including radio modules, gateways, protocols, and server interfaces. It is a wireless communication technology that includes the physical wireless communications, known as LoRa, and the protocol named LoRaWAN, by which the data from the physical world interfaces with server infrastructure.
In 2008 LoRa was developed by Cycleo for wireless communications inspired by military radio technologies. In 2012 Cycleo was acquired by Semtech who manufacture and licence LoRa radio chipsets. LoRaWAN was then developed as a protocol to interface the LoRa physical communications with network servers and software applications. It was first released as a Version 1.0 specification in 2015 and continues to be developed and promoted by the LoRa Alliance which is a global non-profit group of over 500 organisations including Bosch, Cisco, IBM, Orange, and ZTE.
LoRaWAN is an open framework on which solutions can be built and there are many providers of the devices and wireless and server infrastructure required to build end-to-end solutions. It is possible for anyone to build their own LoRaWAN devices, gateways, and cloud services. This is a key differentiator when comparing LoRaWAN to other technologies for smart water metering where key components are often proprietary and challenging to interoperate with components from other vendors. It also means that there are various business models which can be used to offer solutions including low cost annual connectivity fees per device, through to completely free to use public networks.
In Australia there are a number of organisations establishing and operating LoRaWAN networks. These include NNNCo (National Narrowband Network Co), who are building a utility-grade network across the country with high service levels, and Meshed, who are focused on providing community based networks in partnership with councils and other government and semi-government organisations. In many countries around the world, the traditional telecommunication providers are also offering LoRaWAN connectivity such as Orange in France and Spark in New Zealand.
In terms of technical capability, LoRaWAN is positioned between Sigfox and NB-IoT. While LoRaWAN enables more complex functions than Sigfox, particular care must be taken to ensure they are implemented in a manageable way. For example, LoRaWAN can send multiple meter readings in one transmission, but the quantity of readings that can be sent reliably varies depending on signal quality. This means that solutions must be designed to cater to varying scenarios. For these reasons, while anyone can build a LoRaWAN network and solution, it’s strongly advised to engage specialised experts such as network operators and system integrators to ensure expectations are met and reliable operation is achieved.
LoRaWAN is one of the most versatile and flexible LPWAN technologies available and is well suited to many applications and can be used through a range of different business models.
NB-IoT (Narrow Band Internet of Things) is a new wireless network globally standardised by the 3GPP who are the same industry group that standardised 3G and 4G. The standard was frozen in June 2016 and has been adopted by major network carriers around the world. It is operated in Australia by telcos such as Telstra, Vodafone, and Optus on top of their existing telecommunications infrastructure.
The NB-IoT technology can be described as similar to 3G and 4G however with improvements to cater to devices which need to send only small packets of data with long range, higher penetration, lower power consumption, and lower total costs. It achieves these improvements by reducing the transmission speeds and using more efficient connection, transmission and receive methods. Costs are reduced through new pricing plans intended to cater to huge quantities of devices, as well as simpler and lower cost radio modules.
Australia is home to one of the world’s first NB-IoT smart water metering projects. This is a pilot undertaken by the Melbourne utility South East Water with co-operation from telecommunication giants Huawei, Vodafone, and Optus, using meters from vendors including HZ Metering. More pilots and deployments are underway or in planning with other top tier and regional water utilities around the country.
Telstra announced the deployment of their NB-IoT network across all major cities in Australia including regional cities at CES in Las Vegas in January 2018, making it the largest LPWAN network in the country in terms of coverage. Vodafone and Optus also currently have live networks in parts of Sydney and Melbourne with national coverage expected to be announced this year. Public announcements of connectivity plans and pricing from all three operators are also expected to follow.
Most LPWANs use unlicensed spectrums which are frequencies that are open for free public use. Unlicensed spectrums may have limitations such as the number of connections per day or time on air, and may also be susceptible to interference. NB-IoT utilises licensed spectrum which is available only to those who pay for the license e.g. major telecommunication providers. This makes NB-IoT highly robust and reliable, even if congested environments.
Due to its higher data-rate than other LPWANs, NB-IoT can be used for more advanced functions such as larger data transfers to enable multiple meter readings to be sent in one transmission and also firmware over the air (FOTA). NB-IoT also enables the use of a range of application protocols (the format and conventions used to represent data) so that messages sent from the devices can be delivered directly to the applications which will utilise that data. The application protocol LwM2M (Lightweight Machine to Machine) has a standardised library for a wide range of devices including digital water meters.
NB-IoT is one of the most capable LPWAN options and requires very few if any compromises for countless IoT applications including advanced and robust smart water metering.
Comparison of LPWAN Technologies
The below is an unbiased comparison of the three key LPWAN technologies with a focus on smart water metering. While these figures give an overview of some of the most important details to consider, utilities and others who are looking to adopt LPWAN and smart water metering must consider what their specific requirements are before committing to one technology over another.
Many of these figures are indicative of what is found in smart water metering solutions in Australia. It is possible that in some circumstances, these figures could vary. For example, NB-IoT connectivity pricing has not yet been publicly announced in Australia, and LoRaWAN pricing may vary greatly from one network operator to another.
Determining which solutions will work for you can be a complex task with many aspects technical and commercial aspects to consider. To this extent it is important that the real requirements and opportunities to expand the value of digital water metering are clearly defined and that the chosen solution (or solutions) directly addresses these requirements.
Another important consideration is that multiple LPWAN technologies can co-exist within one water network, one project, and even within one geographic region. Meter Data Management Systems, analytics services, utility billing, and other applications should operate in a framework that is capable of, or at least has provisions for, handling data from multiple wireless networks. The best smart water metering systems, smart cities, and intelligent water networks are not just vendor agnostic, but also agnostic in regards to all wireless technologies.
Right now, there are significant incentives and benefits for utilities and other large scale smart water meter users in adopting LPWAN technologies. With these technologies changing the game for smart water metering and digital utilities, and being here to stay, the time to start preparing is now.
Original article by Rian Sullings
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