Nowadays, when technology buffs talk about Wi-Fi, they (we..) are generally referring to the 802.11ac standard found in our latest smartphones and home routers, or possibly 802.11p in the automotive space. However, recently more of these conversations have centered around an older Wi-Fi standard that, thanks to the Internet of Things, is making a resurgence in a big way.
802.11n, which has started shipping in products almost 8 years ago, is now making its way into wearables such as smart glasses and smart watches. In previous generations of wearables, most of the connectivity element was focused on Bluetooth, for power consumption reasons. Wi-Fi, after all, is supposed to consume anywhere between 5x to 50x the power required for BLE.
With the introduction of their smart watch, Apple was the first to rock the boat, integrating both Bluetooth and Wi-Fi 802.11n connectivity. In doing so, the Apple Watch manages to perform data transmission MORE efficiently than a wearable just deploying Bluetooth! This is achieved through combining the strengths of both standards – using Bluetooth to initiate and manage the connection and using Wi-Fi in short bursts to transmit data and immediately turning it off once transmission is complete. As a result, the Apple Watch consumes less energy per transmitted bit compared to using a Bluetooth link for transmission. In turn, this is now driving the integration of Wi-Fi into more IoT and wearable devices.
In addition, the coexistence of Bluetooth and WiFi (both sharing the same 2.4GHz band) can clearly impact the performance and reliability of both wireless interfaces. Apple has decided to rely on Broadcom to solve that coexistence for their Watch.
Are we about to witness a WiFi 802.11n resurrection? And how would SoC vendors approach WiFi+BT coexistence?