Microsoft intends to bring together two communication technologies targeting the IoT landscape: AllJoyn and Thread.
Microsoft has recently joined the Thread Group, an alliance of organizations building Thread, an IP-based wireless networking protocol for connecting home devices. Thread was initially developed by ARM, Nest, Samsung, Yale, and several others, and has gathered the support of more than 100 manufacturers interested in bringing the power of IoT to their devices.
Thread is one communication layer in the OSI model, providing a resilient mesh network topology for devices to discover and interconnect in a secured way. It aims to connect more than 250 devices with no single point of failure, with very little power consumption, enabling them to run for years on a single AA battery. Thread runs on top of 802.15.4 radio waves but its data packets can be also transferred through WiFi networks or the Internet due to its use of IPv6. According to the Thread Group, “millions of existing 802.15.4 wireless devices already on the market can run Thread with just a software enhancement -- no new hardware required.”
IEEE 802.15.4 standardizes the physical layer for a wireless personal area network. It enables short range communication (10 meters) and a transfer rate of up to 250 kb/s. It is geared towards simplicity, low manufacturing costs and very low power consumption, being ideal for IoT devices.
Multiple protocols can run on top of Thread, one of them being AllJoyn. AllJoyn is a an application framework enabling the discovery and communication between various devices without regard to their manufacturer. AllJoyn constitutes the top layer of the OSI model, and can run on multiple protocols, including WiFi, Ethernet, power lines or serial. There are available libraries for C, C++, Objective-C and Java, running on multiple operating systems, including Android, Arduino, iOS, Linux, Mac OS, and Windows. It supports authentication and encryption.
Microsoft is already a member of the AllSeen Alliance, the organization overseeing AllJoyn, and has added support for AllJoyn to Windows 10. They demonstrated building a Universal Windows App using AllJoyn during BUILD 2015.
Microsoft joined the Thread Group with the intent to run AllJoyn over Thread, considering that the two communication channels complement each other, providing “interoperable, secure and robust communications for the expanding world of IoT devices.”