One of the key benefits of Thread we frequently promote, is that it’s able to deliver low-power, extended-range, mesh-networking capabilities, but without requiring a separate hub. But then, we talk about needing Thread Border Routers in order to connect your Thread devices to the network. Needless to say we get a lot of questions — and sometimes criticism — about this apparent contradiction.
To explain why this isn’t a contradiction, and how Thread expands the capabilities of your smart home, without expanding that jumble of cables and boxes under your cabinet, let’s talk first about the role a Thread Border Router plays in your network, and then about how it will actually show up in your home.
Bridges & Hubs
By now, many smart home users are familiar with bridges and hubs. Usually these are stand-alone devices — typically small white boxes hanging off plugs or stashed under your desk. Bridges often come with a particular vendor’s products. For instance you might get one with a set of light bulbs that use a protocol like Zigbee or Z-wave, or a door lock that uses Bluetooth. Or you might get a hub from a smart home platform or security system that lets you connect a number of products to them.
Often companies build or will build products with protocols like Zigbee or Z-Wave because they offer capabilities that Wi-Fi doesn’t, like low power or mesh networking. But these protocols aren’t able to send messages directly to the other devices on your network, or to the Internet, so they need bridges or hubs that can understand the protocols and messages, translate them to a completely different protocol on the other side, pass them along to their cloud or apps, and do the same in the other direction. Because each bridge or hub is specific to that vendor or smart home platform, and often only routes messages to their own app or cloud, you can quickly end up with a cabinet full of multiple bridges or hubs from different companies.
The difference is IP
Thread delivers on the benefits that some of those other protocols have provided, like low power consumption for extended battery life, long range, and increased reliability from mesh networking. However, it has one huge advantage — Thread is based on IP, or Internet Protocol.
One of the amazing things about the Internet is that we’re all able to communicate directly with each other, even as our messages travel over dozens of different networks, radios, and infrastructure. For instance, you and I might use the same app to send a message to each other, but our messages might travel seamlessly over cellular, fiber optic, satellite, ethernet, and Wi-Fi networks on their way to each other.
This is thanks to Internet Protocol (IP), the foundational protocol of the Internet, that allows messages to be transmitted end-to-end across different networks. The infrastructure between sender and receiver — like your Wi-Fi router, or cell tower — doesn’t need to read, process, understand, or translate those messages. It just needs to pass it from one side of the network to the other.
Thread achieves its low power and mesh networking performance by using a specialized radio technology, which isn’t able to communicate directly with Wi-Fi devices. However, because both Thread and Wi-Fi are built on IP, as long as those networks are connected by a router, devices on both networks can talk to each other and to the Internet.
Border Routers
A Thread Border Router is a device that joins a Thread network to the rest of your network, and allows messages to flow between them. That may mean it looks like a bridge or a hub when we draw one in a diagram, but with two important differences:
The first is that Border Routers don’t need to read, modify, or translate the messages that go through them. It simply forwards the message from devices on one side of the network, to their destination on the other side. That means that a Border Router is a generic part of the network — a Thread Border Router from any vendor can perform this function and route messages for any brand of Wi-Fi or Thread devices you might have.
The second — and the reason Thread doesn’t add to your smart home clutter — is that Thread Border Routers, particularly those for consumer applications, are usually built into other devices. Devices you may already own or want to get, like smart speakers, smart home displays, Wi-Fi routers, and yes even those smart home hubs you might have. Companies like Amazon, Apple, Google, Samsung, and others have already announced they’ll be turning on Thread Border Routers in many of their existing products with the launch of Matter. That means tens of millions of homes will be ready for Thread devices, and users can start taking advantage of the new capabilities their smart homes and devices offer, without needing another little white box under the cabinet.