Thread for Access Control and Smart Buildings
The electronic Access control (EAC) industry has been around for almost 5 decades now since the advent of magnetic swipe cards. The access technology at the door has evolved from Swipe cards to RFID based proximity cards to NFC cards and now smartphones. But one thing which has not changed in this industry is the back end communication between the readers and controllers. Wiegand protocol has been used for the last 4 decades. Weigand uses a two-wire interface to transmit data between the reader and the controller. This results in a very rigid hardware system that is very heavy on wiring, conducting and controller panel hardware. Recently the physical security industry has started showing acceptance to cloud-based systems and fully wireless topologies. Wireless mesh is one topology that can be used for a wireless access control system.
Wireless mesh for access control and building automation
Wireless access control system as a concept has been around for a few years now. Standalone solutions powered by Wifi have been deployed by a few manufacturers for small installations where local Wifi availability is there. In a wireless access control system typically the readers act as controllers making the decision of granting access to users. Such systems typically do not need a controller. But for a large commercial multi-tenant project Wifi is not a viable option. With no wires and no controllers, the only way to connect the readers to the access management software is by putting connectivity inside the readers. A wireless mesh topology is best suited for such cases where the readers can communicate with each other over a mesh network. A central edge device called a gateway can then be used as a node in the mesh network to create the connection to the Building LAN or Wifi network. Such systems are best managed using cloud-based software. Bluetooth Low Energy (BLE) Mesh, Zigbee and Thread are a few options available for providing mesh connectivity between readers. In this blog post, we will look at Thread as a connectivity option.
Any application layer which uses IP connectivity can run on top of the thread and this makes it really interesting because many building automation protocols like Bacnet over IP, KNX and DALI can now directly address Thread devices.
What is Thread
Thread is a low power, secure and IPv6 based mesh networking technology for home and commercial IoT products. This protocol was developed by Nest which was then acquired by Google. The Thread group alliance was formed in July 2014 as a working group to aid Thread in becoming an industry-standard by providing Thread certification for products. Thread is based on the 802.15.4 physical layer protocol and uses 6LowPAN for providing IP connectivity. The figure below shows the protocol stack for Thread.
What is Open Thread
Open Thread was released by Google as an open-source implementation of the Thread protocol and is freely available for developers on Github. This allows developers to develop products that can support the thread protocol. But all commercial products need to be certified by the Thread group before they can be used by customers.
Difference between BLE-mesh and Thread
BLE-mesh as a standard has been available since 2017 and has been used in the smart lighting space and Spintly has used its wireless access control solution. The major difference between BLE-mesh & Thread is that Thread is a fully IP based network where each note can be addressed using an IP address from the outside world, while BLE mesh devices have mesh addresses and Gateway is the only device that can recognize BLE-mesh devices. This works in the favour of Thread as many native IP based applications can now seamlessly communicate with thread devices.
Why Thread ?
Thread as a standard is driven by industry leaders like Google, Apple, Amazon and others to ensure interoperability. Thread is also a part of IP-Blis, which is a standard of standards. This allows wireless protocols like Thread or Zigbee to communicate with devices that are using existing standards like BACnet, KNX or DALI. Interoperability and backward compatibility are very important to gradually transition to a wireless solution.
About Spintly and Thread
All Spintly products currently support BLE-mesh technology for wireless communication. All new Spintly products will also support Thread in addition to BLE-mesh. This will allow Spintly products to communicate over other building protocols & standards currently being used. Spintly is currently a leader in wireless mesh-based access control and provides robust physical security solutions to its customers.
