Update, Dec 19: Since yesterday's announcement that Apple, Google, Amazon and Zigbee have joined forces to create a first smart home standard, there have been some new developments. First, Apple has provided "parts" of the HomeKit Accessory Development Kit (ADK) in open source format that developers can use to prototype non-commercial smart home accessories (a license is still required for commercial devices). In a blog post, Apple said that the HomeKit ADK "Open Sourcing Process to Accelerate Development of the New Universal Standard", which it developed in collaboration with the CHIP working group, will be used. CHIP has been ranked as a combination of the best from Apple, Amazon, Google and Zigbee. Parts of this HomeKit-ADK in the new CHIP standard are probably used.
The second development is that Google has a second blog entry on CHIP with some more details. Google went into a little security and said that by using the proven Internet Protocol (IP), CHIP enables direct, private and secure end-to-end communication between devices, mobile phones and cloud services with familiar and consistent features – and programming model that makes it easier for developers to use their experience and solutions in all of these areas. This approach reduces vulnerabilities and vulnerabilities that would otherwise end and restore security. "
enlarge / Google's CHIP pyramid. Note that IPv4 is not supported. RIP.
Google shared this entertaining pyramid chart of the CHIP concept model. According to this diagram, the network only uses IPv6 and IPv4 is not supported. Once you've got IP up and running, CHIP communication can go through pretty much anything, with Google basically listing all of the common network technologies below. Google argues that "IP-based solutions can use a standard network infrastructure that can be shared by many applications and products. This helps reduce the cable clutter and pucks that gateways and hubs nowadays have in many smart home solutions caused."
As we have indicated below, Google sees a certain strength in each of the three most important home networks supported by CHIP. Wi-Fi is fast and the "way to cell phones, internet and cloud services". Thread is used here for efficiency, since the 802.15.4-based network is extremely energy efficient and sensors can be operated with one battery for months. Bluetooth Low Energy is here for "practical reasons" since phones support BTLE almost everywhere. It doesn't sound like Bluetooth is putting a lot of weight. According to Google, it offers "an easy way to connect and set up devices" and "to serve as a direct connection to the mobile environment".