One of the subjects that wasn’t discussed in detail in this blog about selecting a wireless protocol for your IoT design is what happens when you have designed it? i.e. roll-out. No matter how impressive your solution, let’s not forget that from an end customer perspective, this will be one of their most important concerns.
By Tim Bonnett, Director, Alpha Micro Components.
Let’s recap: The low throughput requirements of typical M2M and IoT applications require a different network solution to voice or text traffic. Low-Power, Wide-Area (LPWA) technologies answer this need, proposing low-cost and highly efficient networks that have been designed from the bottom up. With benefits that include power consumption, coverage and pricing over cellular and earlier M2M connectivity solutions, LPWA technologies aim to lower the barriers for designers to incorporate communication into their IoT devices.
Of the LPWA contenders, Sigfox is the most mature. Sigfox started building networks and working with chip suppliers back in 2009. Today, the French company has an impressive network of base stations that cover 17 countries across Europe, America and Asia. Oman, New Zealand and Australia are the latest implementations, and the company plans to cover 60 countries by 2020. There’s been lively discussion about Sigfox challengers recently, from LoRa and Weightless to low power LTE. Sigfox is still the primary contender, in my view, for two reasons: coverage and simplicity of roll-out.
First things first, it can’t be overstated that Sigfox is widely-deployable right now, whilst low power LTE is still being tested. Sigfox’s proprietary technology is based on Ultra Narrow-Band (UNB), employing the license-free ISM bands. One of the reasons why this option is low cost is because of the sensitivity of UNB devices: less base stations are needed to achieve wide area coverage, making it cheaper to install than equivalent GSM/CDMA cellular networks. The Sigfox network allows a bidirectional communication, with up to 140,12B uplink messages and 4, 8B downlink messages per day. With data rates of just 100b/s, this allows Sigfox-based nodes to run for over a decade from a single battery. Another plus, from a design point of view is that it can co-exist with other communication protocols. An example is LoRaWAN, which Libellium has used in combination with Sigfox for a smart parking device.
Let’s now take a closer look at what’s makes Sigfox simple for customers. A key advantage is its focus on providing a hassle-free way for new entrants to quickly design and deploy new devices. Sigfox gives away the hardware in the form of IP for modules or transceivers - such as the AX-SIGFOX SoC from ON Semiconductor - and it sells the software/network as a service. Partner equipment is validated by Sigfox through its certification program, meaning that Sigfox-ready silicon really is ‘ready to go’.
From an end customer perspective, Sigfox has a subscription-based approach whereby they sign up for a single contract to access global coverage and so as long as there’s a Sigfox network, products will work across different markets. In France and the U.S., Sigfox owns and operates the network, but elsewhere, an ecosystem of network partners - each with exclusivity in their country - sells the technology to customers, paying a royalty to Sigfox. Like some other LPWA technologies, another advantage is that Sigfox’s subscriber IDs are embedded, meaning there’s no SIM cards and no subscriber lifecycle management to handle.
An additional positive for end customers is that Sigfox has recently addressed the issue of data collection, analysis and storage by teaming up with Microsoft. Sigfox’s own cloud is now linked to Microsoft’s Azure cloud service, which has the capacity to connect and control millions of devices. Azure will help end customers develop the analytics in order to make sense of all the data being collected.
Of course, for Microsoft and other Cloud service providers, IoT is the ‘killer app’, but the Cloud is also the key enabler of IoT. Ultimately, what all IoT devices are about is being able to gather data from the world around us, so that we can understand it better and adapt more quickly. Sigfox is helping to forge this revolution, and by smoothing the roll-out path for end customers, is also smoothing the path to IoT acceptance in what must feel to many as uncharted territory, with all the potential hazards that brings.