The city of San Francisco recently made headlines after the France-based firm Sigfox completed its installation of a wireless communication network that will be used exclusively for smart city systems and solutions that leverage Internet of Things (IoT) technologies to help make the city more efficient. San Francisco is the first city in the US to deploy a wireless network that’ll be 100% dedicated to IoT applications. And importantly, that network isn’t a wireless carrier’s LTE network. Instead, Sigfox has built a low-power wide-area (LPWA) network that relies on antennas that the company installed atop roofs throughout San Francisco.
The IoT industry is now trying to figure out the best way to enable all the “Things” in the Internet of Things to be able to communicate with one another. Sigfox’s solution is just one of a number of ways these devices can transmit data.
Building Blocks for the Internet of Things
In building out the network backbone for various IoT applications, there are four important considerations:
- Space: The Internet of Things comprises million and millions devices, and its scope will continue to grow exponentially as more IoT applications, devices and use cases emerge. It’s hard enough to handle the amount of the video data and demand across wireless networks now, both cellular and Wi-Fi. How will we have enough bandwidth for millions of connected appliances, street lights, fitness wearables, and other smart devices?
- Battery life: the Internet of Things will only be useful to consumers and companies if the ‘Things’ are able to communicate; for plugged-in appliances, power consumption is less of an issue, but battery life on other wireless devices is a huge consideration. For smart city initiatives, how will city governments keep up with switching out batteries on the hundreds of thousands of smart sensors they’ll want to deploy around town? The same can be said for companies looking to utilize IoT technology to help monitor production, for example, across sites and locations. And for consumers — who struggle now to keep up on battery changes for their smoke detectors — how often will they remember to change the batteries on their lawn irrigation monitors, or security devices, for example? And how useful is any personal connected T-shirt, watch or other device if its battery dies in the middle of the work day, for example, or when the consumer is away from a charging station? How many chargers will we need to carry in the future, to ensure all of our wireless devices are able to remain so?
- Range: Communication networks for IoT devices will need to be ubiquitous so that all the devices within a system can connect and communicate to one another. That being said, it’s likely that in the initial stages of IoT deployment, different types of IoT applications will utilize different types of wireless networks. For example, an industrial IoT system may want to use cellular or LTE, which can be made available in more remote regions; and a city like San Francisco may want to build its own wireless network to be used exclusively for city-related connected devices, in order to curb interference and assure functionality. And in-home IoT applications (as we will see below) may be able to perform their duties using other forms of communication — LED lights, for example — to communicate with one another without interfering with the home Wi-Fi network.
- Cost: whatever communication network a technology utilizes for IoT deployments, it will become effectively moot if the needed chips are too expensive to be added to the devices.
3GPP Standardizes on ‘NB-IoT’
The standards body 3GPP decided on narrow band LTE for its approved IoT devices and technologies. It’s referred to as NB-LTE for IoT, or more simply NB-IoT. Narrow band LTE has many advantages for industrial and network-wide IoT applications.
First, it’s a part of 4G LTE technology, which will serve to help future proof any connected devices. Most IoT applications available today utilize 2G technology, which will become obsolete in a few years, and render all those connected devices dead. NB-IoT requires less power consumption from the devices themselves, which helps to extend battery life to its fullest; it offers wider indoor coverage for the wireless carriers, low device cost, low delay sensitivity, and can support large numbers of low-throughput devices sending data; and wireless carriers will be able to deploy the technology using their existing resource blocks in their LTE networks and unused resource blocks in the guard band, it can be deployed on dedicated spectrum, and can be deployed on re-farmed GSM channels.
“We have now set a clear path in Release 13 to meet the needs of the 3GPP industry to further address the promising IoT market,” said Dino Flore, the chairman of 3GPP RAN. “After lengthy discussions, we came up with a harmonized technology proposal with very broad industry support,” Flore said, referring to the fact that some industry heavyweights, including Intel, Nokia and Ericsson, have officially stated their support for NB-IoT based chipsets and IoT applications.
Intel said recently it “intends to support commercial rollout of the technology with a roadmap for NB-LTE chipsets and product upgrades beginning in 2016 that will enable slim form factors,” and that “Nokia and Ericsson will provide the required network upgrades to support an extension of existing LTE networks with NB-LTE optimized for low-power machine-to-machine communication.”
LPWA Networks and ISM Bands
Companies, particularly those offering IoT solutions but who don’t own spectrum themselves, are looking at other means of communication between devices. Sigfox’s technology, for example, relies on a low-power wide-area (LPWA) network, which utilizes the unlicensed spectrum bands referred to as “Industrial, Scientific and Medical” (ISM) bands.
These bands have their own set of pros and cons. For starters, companies don’t need to own their own networks in order to build solutions that utilize unlicensed spectrum, which opens up the IoT playing field to companies such as Sigfox and others; on the other hand, applications that operate on ISM bands will be limited in their functionality by these bands’ inherent characteristics — lack of reliability or scalability, for starters.
LPWA solutions might be suitable for dedicated smart city infrastructure with limited geographic reach, for example, but not for global, or even nation-wide deployments of IoT solutions or services.
LED and Li-Fi Applications
Companies are also eyeing LED-based communication technologies as medium through which devices may connect and talk to one another. LED lights can be used to transmit binary data by being switched on and off at speeds too fast for the human eye to detect. Companies such as General Electric (GE) and Philips are already using data-transmitting LED lights — also referred to as “Li-Fi” — in their stores and warehouses, for example.
Disney’s research arm has been experimenting with toys that use LED light to communicate with one another and mobile devices. In September, Disney released a paper outlining its experiments, which involved a regular LED bulb, modified with a System on a Chip (SoC) running Linux, “LED light bulbs provide a foundation for networking using visible light as communication medium,” Disney said in its paper. “With visible light communication [VLC], LED light bulbs installed in a room can communicate with each other and other VLC devices.”
Disney added sensors to its LED bulbs, enabling them to both transmit and receive data from other LED lights, toys, mobile devices or other wearables through light, without the need for Wi-Fi or Bluetooth. These LED bulbs could also be used to create smart lighting networks.
“The initial prototype has not been optimized for performance, and a number of important issues deserve further investigation, but the system provides a proof of concept that indeed the IP stack and the proposed VLC protocols are flexible enough to inter-operate,” Disney said.
Here’s a video Disney released demonstrating some potential uses of the VLC technology.