The case for Wi-Fi in the Internet of Things
Whether it’s the "connected home" or the "Internet of Things," many everyday home appliances and devices will soon feature some form of Internet connectivity. What form should that connectivity take? Ars Tecnica sat down with Edgar Figueroa, president and CEO of the Wi-Fi Alliance, to discuss his belief that Wi-Fi is the clear choice.
Options are plentiful when it comes to the Internet, but some are easily disregarded for most Internet of Things designs. Ethernet and other wired solutions require additional equipment or more cabling than what is typically found in even a modern home. Cellular connectivity is pointless for stationary home goods and still too power-hungry for wearable items. Proprietary and purpose-built solutions, like ZigBee, are either too closed off or require parallel paths to solutions that are already in our homes.
Bluetooth makes a pretty good case for itself, though inconsistent user experiences remain the norm for several reasons. The latest Bluetooth specifications provide very low power data transfers and have very low overhead for maintaining a connection. The result is that the power profile for the connection is low whether you’re transacting data or not. Connection speeds are modest compared to the alternatives. But the biggest detractor for Bluetooth is inconsistency. Bluetooth has always felt kludgy; it's an incomplete solution that will suffice until it improves. It's helpful that Bluetooth devices can often have their performance, reliability, and features improved upon through software updates, but the experience can still remain frustrating.
Then there’s Wi-Fi.
Figueroa wanted to highlight a few key points from a study the Alliance commissioned. “Of those polled, more than half already have a non-traditional device with a Wi-Fi radio,” he said. Here, “non-traditional” falls among a broad swath of products that includes appliances, thermostats, and lighting systems. Figueroa continued, “Ninety-one percent of those polled said they’d be more likely to buy a smart device if it came equipped with Wi-Fi.” Alliance’s point: everyone already has a Wi-Fi network in their home. Why choose anything else?
One key consideration the study seems to ignore is power draw, which is one of Bluetooth’s biggest assets. Wi-Fi connections are active and power-hungry, even when they aren’t transacting large amounts of data. A separate study looking at power consumption per bit of data transferred demonstrated that Wi-Fi trumps Bluetooth by orders of magnitude. Where Wi-Fi requires large amounts of constant power, Bluetooth requires almost no power to maintain a connection.
In response to a question on the preference for low-power interfaces, Figueroa said simply, “Why?” In his eyes, the connected home isn’t necessarily a battery-powered home. Devices that connect to our Wi-Fi networks traditionally have plugs, so why must they sip almost no power?
Bluetooth has its place in devices whose current draw must not exceed the capabilities of a watch battery. But even in small devices, Wi-Fi’s performance and ability to create ad hoc networks and Wi-Fi Direct connections can better the experience, even if it's at the risk of increasing power draw and battery size.
In the end, the compelling case for Wi-Fi’s use in the mobile space has more to do with what we want from our experiences than whether one is more power-hungry. Simplicity in all things is preferred. Even after all these years, pairing Bluetooth is usually more complex than connecting a new device to your existing Wi-Fi network. Even in the car, where Bluetooth has had a long dominance, the ability to connect multiple devices over Wi-Fi’s wide interface may ultimately be preferred. Still, despite Figueroa’s confidence, it's an increasingly green (and preferably bill-shrinking) world looking to adopt an Internet of Things lifestyle. Wi-Fi may ultimately need to complete its case by driving power down enough to reside in all our Internet of Things devices, from the biggest to the smallest.
Source: Ars Technica. Read more here.