Bigger is better?  Not for the Internet of Things…

In my last article, we talked about the Need for Speed and discussed MIMO streaming technology to increase throughput.  While extremely important for applications that require large amounts of data to be transferred, this isn't always on the forefront of an engineer’s mind when designing new products.

More and more, especially with the Internet of Things, the objective is to be smaller, lighter, and less expensive.  These new generations of radios are focused on low power and cost over features like throughput and range.

In this article, we’ll look at compact, lightweight, and power efficient wireless technologies, as well as discuss some of the broad challenges in this new market.

But First, Some Background…

Most people remember that Wi-Fi was originally developed for the desktop PC.  As the technology has matured, become more cost effective, and required lower power, it has migrated to more applications.  Printers, TVs, digital cameras, and Network Attached Storage devices (to name a few) have all integrated Wi-Fi into previously hard-wired peripherals.

And the trend continues.

As the Internet of Things becomes more popular, Wi-Fi will move into air conditioners, refrigerators, water heaters, lights, thermostats, and every other home appliance and service you could imagine. However, there are some significant challenges still left to achieve such vision.

No Standard Protocol…

Wi-Fi’s origins as a PC based protocol have significantly impacted the standard connection procedure.  In the past, a user connected directly to a website through a terminal.  For example, because I’m writing this blog post on my laptop, I may open Google Chrome to connect to the Internet and research information.  Now, let’s say that I move to my phone.  I no longer open Chrome, but rather connect to Wikipedia through an App.

Now, let’s move one step further and think about how I would connect to the internet if I was a home audio receiver.  I want to automatically find and access content stored on a Network Attached Storage (NAS) device.  How do I do this?

One such standard exists to accomplish this called DLNA.  Developed originally by Sony, this propriety standard has become relatively well adopted throughout home audio peripherals.  Or, I could use a number of other protocols, such as SLP, UpnP, WSDP, mDNS, etc.  And that’s the problem.

More than 50 such major protocols exit, as well as a number of minor ones.  There are too many standards available to use, effectively negating the concept of a standard.  And that’s just for home audio.

Let’s say I’m now a washing machine.  No such standard exists if I wanted to communicate with a dryer, or in general, automatically initiate any other similar Machine to Machine connections.  This needs to be addressed as we move forward with the Internet of Things vision.

Direct Connections…

Again, because of the origins of Wi-Fi, the normal mode of operation has been to have a number of clients (laptops, phones, etc.) connected to one host (router or Access Point).  But what if you only want to share information directly between two devices?

In the past, the only option was to establish an Ad-hoc network for point to point communication.  This method comes with a number of disadvantages outside the scope of this blog post, but the important point is that Ad-hoc networks were never widely adopted due to these limitations.

In response to this, the Wi-Fi alliance has established a protocol called Wi-Fi Direct, which allows the client to work as a simple Access Point to create a point to point wireless network.  This new standard allows for direct connection to modules that normally operate in client mode.  Normally used for configuration, this concept also has widespread applications in computer peripherals such as mice and keyboards, as well as in applications that have no display and rely on a mobile phone for configuration.

Lower Power Consumption…

Traditional embedded Wi-Fi products operate at approximately 1.5Watts; 1W when receiving and 2W when transmitting.  This is extremely high for an embedded home environment and where the other typical radios, like Bluetooth or 802.11.4, operate around 0.1 W.

Wi-Fi has remained high power to accommodate higher throughput and longer range, but since this is no longer a necessary requirement for some, a new generation of low power, low data rate modules are coming on the market.

One such module is the SX-ULPAN from Silex Technology.  Using the incredibly power efficient Qualcomm QC4004 radio and operating with standby current in the uA range, this device is geared towards filling the need of a low cost, low power, low data rate application.

Speaking of Lower Cost…

Higher volume dictates a lower price, but in the case of Wi-Fi, it’s a chicken and egg game.  As long as Wi-Fi is an optional PC module, the demand will not dictate the lower pricing that is required to adopt into the Internet of Things.

Wi-Fi chip makers who develop their modules to be soldered down next to a high power processor (like a cell phone) have the volume to dictate a low price, but represent another inherent problem.

If module makers are aiming to be in air conditioners or refrigerators, the first generation of solder down modules that attach to a high powered processor aren’t enough.  This is because a washing machine uses a CPU equivalent to that of a 20 year old graphing calculator.  Such devices are not geared to accommodate the traditional driver/radio setup and need something new – a processor and radio integrated into a single chip solution.  This is where the QCA4000 family from Qualcomm and the development of the SX-ULPAN module come in.

In Conclusion…

A few chip vendors, like Qualcomm, are beginning to address the need of the low cost, low power market.  Even so, this first generation of Internet of Things devices has a bit further to go before cost, ease of development, and functionality are addressed enough to  see widespread adoption.