Bluetooth SIG Eyeing Range Boost for Audio in Next Release of Bluetooth Specification

Bluetooth Smart, finalized in Bluetooth 4.0 in summer 2010, has had the “fastest wireless technology adoption ever,” Suke Jawanda, chief marketing officer for Bluetooth Special Interest Group, told us at a Bluetooth demo event in New York this week. Bluetooth Smart “appcessories” alone are expected to account for Bluetooth 4.0 chipset shipments of 220 million units this year, up from 80 million last year and 20 million in 2011, Jawanda said. He projected shipments will grow to a billion units by 2016. Appcessories include devices like fitness trackers that communicate data to Bluetooth Smart-enabled apps, he said.

Within 12 months of the adoption of Bluetooth 4.0, the first Bluetooth Smart-enabled products appeared and the technology took off after 18 months when Apple unveiled “hub” products including the Apple 4S, MacBook Air and Mac Mini that were Bluetooth Smart-ready, Jawanda said. “Virtually all” Apple devices now support Bluetooth Smart as do Windows 8 and 8.1 products, he said. Android’s latest version, 4.3, is now Bluetooth Smart-ready and future versions will support it, he said. “The scale sets the stage for all these things to talk to each other,” he said. Chip makers including Broadcom, Qualcomm and Texas Instruments introduced products early on, and now a new group of smaller chip makers including Nordic and Cambridge Silicon Radio are adding to the mix “because the volume is there,” Jawanda said.

Audio was the first “revolutionary” driver of Bluetooth technology, finding its way into portable speakers, headphones and soundbars. Appcessories enabled by smart technology in Bluetooth 4.0 are the second wave, Jawanda said. The role of Bluetooth has evolved from a point-to-point relationship to that of “feeding an application.” Bluetooth Smart-enabled medical devices send data to an app on a phone, tablet or PC that’s converted to useful information for the user, he said.

Bluetooth Smart is an “ultra-low-power” solution optimized for “little bursts of data” compared with high-power Bluetooth audio applications that have to transmit a steady stream of high-quality data such as voice and music, Jawanda said. Power is measured by how fast a radio can wake up, send data and go back to sleep, with power efficiency determined by how long a radio is “off,” he said. Wi-Fi and Bluetooth aren’t appropriate for appcessory devices because of the power draw, he said. The Wi-Fi power cycle takes roughly a second or “hundreds and hundreds of milliseconds,” he said, compared with basic Bluetooth used in audio products that’s less than 50 milliseconds. Bluetooth Smart radios cycle in three milliseconds, making them highly power efficient, Jawanda said.

Power efficiency translates to battery life, which is important to consumers. Jawanda cited Polar, a maker of stride sensors for runners, which introduced a device using Bluetooth “classic” a couple of years ago and then updated to Bluetooth Smart last spring. Under normal use the coin-cell battery in the first tracker lasted for several months, and with Bluetooth Smart, the battery can last “a couple of years,” he said.

While music applications will continue to require the higher data rate features of Bluetooth Enhanced Data Rate for high-quality data transfer, “almost anything else” isn’t sending a load of data that requires a continuous stream, Jawanda said. “That why Bluetooth Smart has exploded,” he said. Device makers had been waiting for a solution that was more power-efficient. He cited the example of a wearable baby monitor that can be in constant use for up to six months without a battery replacement.

Security has always been important in the Bluetooth world, but transmission of sensitive information such as health data made Bluetooth SIG “double down on security” in Bluetooth Smart with “military-grade” 128-bit AES encryption, Jawanda said. Additional security comes via adaptive frequency hopping, which breaks data into bits spread across a number of channels before being reassembled at the other end of the transmission, he said. Bluetooth Smart operates in the crowded 2.4 GHz frequency band along with Wi-Fi. In a high-traffic wireless setting such as a hospital, “if you're monitoring a patient’s vitals wirelessly, the data has got to get from point A to point B securely,” he said.

The proliferation of devices is making Bluetooth Smart implementation more affordable, Jawanda said. Volume has driven down hardware chip costs to under a dollar for a Bluetooth Smart radio, compared with early chipsets in the $1.50 range, he said.

The next release of Bluetooth 4.0 will be out before year-end and will be geared toward improving usability for consumers so products “just work without you having to do much,” Jawanda said. That won’t include eliminating the pairing step, he said. “We always want pairing” because it’s part of the security piece of Bluetooth, he said. “You've got a device that’s broadcasting and you don’t want just anything to talk to it,” he said. Bluetooth SIG wants pairing to be as simple as possible as long as consumers can explicitly approve their device communicating with another device. Another pillar of the next release of the Bluetooth spec will be around making use more flexible for developers, he said.

The third pillar of the next version of Bluetooth is to take Bluetooth to the Internet of Things, Jawanda said. Now Bluetooth devices talk to a phone, but there are instances where consumers would want information to go directly to the cloud, such as patient monitoring, he said. A body sensor that measures blood pressure should be sending data to the cloud “because the cloud is what’s monitoring you,” he said. In order for a doctor to be alerted to a patient’s status, “you need to be connected to the cloud,” he said. “You can’t always count on your phone to be on.”

Bluetooth SIG hopes its role in the Internet of Things will be the “low-power link,” Jawanda said. His vision includes toothbrushes, toys, medical devices and fitness trackers that today communicate with phone apps in the future sending data directly to the cloud.

On the audio side, Bluetooth has been limited to the roughly 30-foot range between a music source and a wireless speaker. That has left multi-room audio systems to rely on Wi-Fi for longer distances. Bluetooth SIG is “looking at range,” Jawanda said, and “I think you're going to see some really good things in the foreseeable future.” There are “different ways to skin that cat” in terms of increasing range for audio transmission, he said. “That’s clearly something we're looking at.”