Thursday, January 21, 2016

New 802.11ah standard for IoT comes with tempered expectations

This year's annual Consumer Electronics Show (CES) announced details around a very important new standard for managing the Internet of Things - 802.11ah, also known as HaLow.

HaLow extends the consumer WiFi radio frequency spectrum to include sub-1 GHz frequencies at low-power. The lower, 900 MHz frequency enjoys longer range (roughly twice the distance of current 2.4 and 5.0 GHz frequencies used in consumer WiFi) at the expense of throughput, as well as lower power ratings. As these devices connect on separate, 900 MHz channels, adopting them onto your network theoretically means less contention and interference with existing smart phones, laptops, and tablets already dominating the 2.4 and 5.0 GHz frequencies.

However, it's worth noting that there are plenty of devices out there already living in the 900 MHz space. Wireless internet service providers, for example, often utilize 900 MHz connections in areas where trees and other obstacles make a 2.4 or 5 GHz signal impossible. AV equipment, blue-tooth, and cordless phones are also often found utilizing 900 MHz for their wireless functionalities.

Power needs represent another potential concern with adding an additional 900 MHz radio to access points already sporting 2.4 and 5.0 GHz radios - particularly for those rated for Wave 2 802.11ac. Access points certified for the wave 2 ac standard require a lot of power. In fact, a whole new standard for POE (power over ethernet) was adopted to support them called 802.3at or PoE+. While the power footprint of a 900 MHz radio is less severe on it's own, it still isn't clear if an already power-hungry dual-band wave 2 ac access point can handle a third radio on the existing 802.3at power standard. A third power standard may also be needed to allow such a device to powered over ethernet.

It's worth bearing in mind that even the best guidelines and standards for WiFi aren't fool-proof, and there's no shortage of devices out there that while technically abide by a given WiFi standard, still sport wonky radio behaviors, shoddy security capabilities, or poorly implemented network drivers. These poor practices can't be solved by a new standard and spectrum option, and time will tell if consumer device manufacturers are mindful of these dynamics as they begin to release IoT devices for 802.11ah.

We're not likely to see many HaLow compliant devices for another year or two, which gives administrators and WLAN designers time to familiarize themselves with appropriate spectrum plans that include 900 MHz. However, device manufacturers are the ones who really need to get it right first, or even the best admins will be facing unpleasant complications by 2018.

No comments:

Post a Comment