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EETE SEP 2015

Microwave & RF circuits IoT network concerns By Rick Merritt The Internet of Things lacks a wide area network with broad coverage and low cost, according to a panel of experts working to bridge the gap to fuel IoT deployments. Today’s long range machine-to-machine networks generally use wired or cellular links that are widely available but too expensive to be profitable, said Syed Hosain, chief technologist at Aeris Communications Inc., an M2M carrier. In the next couple years, none of a handful of emerging technologies likely will have the coverage needed to spark widespread use, he said in a panel at the recent ESC SV event. People deploying IoT networks don’t want to have to think about whether a network is available in their area, said Hosain whose first customers were alarm and trucking companies offering services across the U.S. “I postulate that for the next ten years cellular is the only viable option for that kind of coverage,” Hosain said. “I’m not sure where we will get the dollars to deploy these new IoT networks,” he added. The LoRa Alliance led by Semtech has the best shot at being the first to have broad coverage, in part because it has backing from more than 90 companies including Cisco, IBM, Microchip and SK Telecom, Hosain predicted. One U.S. carrier is said to be close to signing a deal to deploy the 900 MHz LoRa net in one of its U.S. regional markets for applications such as smart buildings, agriculture and asset tracking. Sigfox (Toulouse, France) is widely thought to have an edge because it already has national networks in a handful of European countries and snagged more than $90 million last year to deploy a U.S. network. In February, Sigfox said it plans to 1,300 base stations in ten U.S. cities by the end of the year - including Houston, LA, New York, Portland San Francisco and Seattle - and as many as 4,000 base stations covering a total of 30 cities by the end of 2016. Hosain praised Sigfox for its simple API and network architecture, Low power wide area (LPWA) networks will make up just 14% of all M2M links by 2024. but said having coverage limited to 30 cities over the next year and a half was subpar. He also expressed concern SigFox may not be able to meet an FCC requirement to limit 900 MHz networks to 400 millisecond transmissions when deployed in urban environments. The FCC requirement is the reason Sigfox limits nodes to transmitting 140 12-byte messages and receiving four 8-bytes a day, Hosain said. In addition, he took issue with the Sigfox business model of charging a fixed cost per node, estimated at about 1-10 euros a year. A Sigfox representative was invited to the panel but was unable to attend and did not answer questions sent via email. Data plans of any sort are beyond the budget for many IoT applications, said Paul Peck, a representative of the 900 MHz NWave technology which is the basis for the Weightless-N specification. Most apps “just need to say a trash can is full or not, or let you know that the ground is moist or dry,” he said. Peck said the NWave network supports a 3-10 km range, depending on environment conditions, 20 byte payloads, with “virtually unlimited” daily updates, up to 7 years of autonomy on 3.6V lithium-chloride batteries and bidirectionality coming in a 3Q 2015 update, all at a $4,500 cost per base station, not including installation. By 2024, the emerging class of low power nets such as LoRa, Sigfox and NWave may carry nearly half the wide area IoT traffic, according to estimates by market watchers at Machina Research. However they will still only represent 14% of all IoT nets, the vast majority of which will be confined to short range links in the home or office typically using Bluetooth, Wi-Fi and Zigbee, it said. Wi-Fi in the equation Cellular and Wi-Fi proponents are not standing still when it comes to IoT, but they are not moving very quickly either. The specification for a so-called Cat-M version of LTE optimized for IoT networks will not be ready until sometime in the first half of next year. It could take more than a year for networks to enable it. The good news is Cat-M could enable building a power amplifier in CMOS for more integrated baseband chips, said Eran Eshed, co-founder and vice president of marketing and business development at Altair Semiconductor during a round table at this year’s Silicon Valley Embedded System Conference (ESC SV). The integrated chips could enable engineers to build $5 LTE modules, a Holy Grail for cellular M2M pricing, he said. Chip designers such as Altair and Sequans are banking on a market for such low power, lost cost LTE devices. At least one other cellular option is in the works, a variant of 2G or 3G networks known as cellular IoT. It has backing from giants such as Huawei and Qualcomm, but is still in an early stage of development, Eshed reported. In the meantime, companies such as Altair are sampling Rick Merritt is Silicon Valley Bureau Chief at EE Times - www.eetimes.com 38 Electronic Engineering Times Europe September 2015 www.electronics-eetimes.com


EETE SEP 2015
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