Low-power Wi-Fi modules target IoT - Embedded.com

Low-power Wi-Fi modules target IoT

PARIS — Among wireless technologies powering Internet of Things (IoT) connectivity, Wi-Fi has been conspicuously absent from Silicon Labs’ IoT product portfolio — until now. The Austin, Texas, company is formally joining the Wi-Fi in-crowd with home-grown low-power Wi-Fi transceivers and Wi-Fi modules designed for battery-operated IoT devices. The company is making the announcement Monday (Feb. 26) at a trade show in Nürnberg, Germany.

Silicon Labs is touting its Wi-Fi solution’s “exceptionally low transmit (TX: 138 mA), and receive (RX: 48mA) power, along with 200 µA average Wi-Fi power consumption will enable ultra-low system power for IoT devices.”

Silicon Labs' WFM200 Wi-Fi Module (Source: Silicon Labs)  Click here for larger image

Silicon Labs' WFM200 Wi-Fi Module (Source: Silicon Labs)

Daniel Cooley, senior vice president and general manager of IoT products at Silicon Labs, told us, “We’ve been thinking of how to enter the Wi-Fi market, when to do it and what makes sense for us to do it,” especially after “tons of money already invested into Wi-Fi chip companies over the last 20 years.”

Wi-Fi for battery operated devices
So, why Wi-Fi now?

First, this is all about ubiquity. Wi-Fi is the most widely deployed wireless technology in the world, said Cooley. “When a consumer walks into McDonald’s, he expects to have a Big Mac and Wi-Fi,” he said. More specifically, Wi-Fi access points are already installed everywhere, he added.

Second, the IoT market is facing requirements to enable transmission of more and more data. “There are more IoT apps — like IP cameras — that need to pump a lot of data,” said Cooley. In parallel, those who build IoT systems also demand a fatter pipe for more frequent software updates, especially when patching security updates.

However, as IHS Markit’s senior analyst Christian Kim noted, despite Wi-Fi’s geographic spread, Wi-Fi’s high-power consumption compared to other wireless standards has “made it prohibitive for line-powered/battery powered applications” to embrace Wi-Fi on IoT devices.

Silicon Labs is hoping that a low-power Wi-Fi technology that meets the tight power budget of battery-operated devices will change the landscape.

IHS Markit predicts that the market for Wi-Fi devices in low-power IoT end-node applications to grow from 128 million units per year in 2016 to 584 million by 2021.

But now, given the glut of Wi-Fi chips on the market, how exactly will “Wi-Fi for IoT devices” differ?

Wi-Fi chips today “don’t respect network or data,” said Cooley. “Wi-Fi has notorious protocols that flood the network with packets. If the other device didn’t get a packet, it keeps chirping and chattering away — with no respect for the network where other wireless protocols exist.”

IHS Markit’s senior analyst Kim agreed. “Traditional Wi-Fi chips constantly connect to the network bringing the network performance down,” Kim said. Low-power apps need “low-power Wi-Fi chips,” he noted. The low-power Wi-Fi chips are designed to remain disconnected to the network and reconnect to the network only when the network has enough bandwdith available.

More specifically, “Clients will let go” of packets and try re-sending them later, said Cooley. Clients know effective throughputs, so once the network starts degrading, it backs off and lets others use the network. When it clears, it re-sends packets at a higher data rate. Cooley said, “Some access points manage the network better, as they started to embrace such flexible schemes.”

Silicon Labs also noted the company’s core RF performance improves the sensitivity and link budget of its Wi-Fi solution, resulting in a link budget of 115dBm for long-range Wi-Fi transmission.

Continue to page two on Embedded's sister site, EE Times: “Silicon labs juices Wi-Fi in IoT portfolio.”

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