It's been around a while now, some 20 years or so, Bluetooth is about to get a significant upgrade so it can use Mesh networking. The idea behind this is to make it much more usable for Smart Home and IOT applications.
"Bluetooth is a wireless technology standard for exchanging data over short distances (using short-wavelength radio waves) from fixed and mobile devices, and building personal area networks (PANs). Invented by telecom vendor Ericsson in 1994, it was originally conceived as a wireless alternative to RS-232 data cables" from Wikipedia
So what is mesh networking? it's simply whereby each point or node (thing if you like) acts as a potential relay unit for network data/signals. It was invented by the military to make sure that if one node or point was destroyed data could still pass through the network. basically each piece of hardware acts as a mini-router, data can take the fastest way through the network and doesn't matter if pieces of the network are missing.
Verge have an article on the upgrade;
"There’s a long-running fight between wireless standards to be the one and only to connect all the smart devices in your home. And with an upgrade today, Bluetooth is making a good case for itself.
Bluetooth SIG, the group that oversees the Bluetooth standard, is today releasing the specification for Bluetooth Mesh. If you’re familiar with mesh networking, Bluetooth Mesh is pretty much exactly what it sounds like: it allows low-power Bluetooth devices to create and act like a mesh network.
If you’re not familiar with mesh networking, here’s what it means: most wireless communications go straight from one point to another — say, from your router to your laptop and back again. If your laptop is too far out of range, then you’re just out of luck.
DEVICES CAN WORK TOGETHER TO SEND DATA A LONGER DISTANCE
But mesh networks have a useful trick to help data travel longer distances: communications can hop between devices. So if a signal can’t reach its destination on the first try, another device on the network can re-transmit the message, sending it out even farther in hopes of finding the device it’s trying to get in touch with. And this can happen again and again, until the message finally gets where it needs to go.
This is particularly useful for smart home tech, because it allows a device in one corner of the home to send a message that reaches smart devices in all the far nooks and crannies of a house. So a garage door opener, for example, could send a message to turn on the upstairs bedroom lights when you arrive home from work, with the message hopping from one smart light to another in order to reach the distant bulbs.
Mesh networking is also important because many of these devices need to run on very little energy. Sending out a fast signal that stretches from one side of a house to another requires a lot of power, but mesh devices can send out lower-power signals because they’ll get picked up and repeated. That’s important for a device like a battery-powered temperature sensor, so that it can stay running for longer without needing its batteries to be replaced.
Bluetooth SIG is accounting for a bunch of different types of devices using Mesh. It won’t require all devices on a network to rebroadcast signals, for instance, so that they can save even more power. In some cases, really low-power devices may only wake up every few hours and ping a “friend” device (say, a temperature sensor reaching out to a thermostat) to receive any pending messages, like an update to the temperature range it’s supposed to track. The Mesh standard also requires all communications to be encrypted.
BLUETOOTH MESH DOESN’T REQUIRE NEW HARDWARE, BUT YOUR DEVICE MIGHT NOT GET AN UPGRADE
Unfortunately, your existing Bluetooth devices aren’t going to suddenly get these abilities overnight — or, potentially, at all. Bluetooth Mesh can be added to any device that already supports Bluetooth 4.0 or 5.0, which is good because it means new hardware isn’t required, so a lot of devices can get support. But whether current devices receive it depends on if their manufacturers release an update.
Bluetooth SIG says that it usually expects to see new Bluetooth standards starting to enter the market about six months after they’re released. In this case, it expects Bluetooth Mesh to show up even sooner, since new hardware isn’t required. So there’s a good chance your next Bluetooth device will support mesh, but there’s no guarantee your current ones will.
That said, Bluetooth SIG is preparing for some devices to not get an upgrade. It’s allowing some mesh devices to act as “proxies,” which allow other Bluetooth products to connect to and control devices on the network. That way a phone might be able to connect to a mesh proxy and tell some lights to turn on.
BLUETOOTH WON’T BE THE ONLY STANDARD, BUT IT COULD BECOME AN EVEN MORE POPULAR ONE
While these changes make Bluetooth far more useful for smart home devices, that doesn’t mean they’re going to end the standards battle anytime soon. For one, we have to wait for a good number of mesh devices to arrive to make the feature useful. Then, we have to see how well Bluetooth Mesh actually works — though Bluetooth has improved in recent years, it’s had reliability and connection issues in the past. If that’s the case here, then Mesh will be a nonstarter.
On top of that, Bluetooth still isn’t perfect for everything. It’s not trying to replace Wi-Fi for high-speed connections, so some devices will still support that. Other products, like Philips’ Hue lights, rely on mesh networking standards, like ZigBee, that are already in use, albeit with far less name recognition and widespread compatibility. Meanwhile, the group that creates Wi-Fi is working on a low-power spec to start going after Bluetooth’s turf, continuing the fight.
It’s never seemed like there would be one and only one wireless standard, no matter how hard these standards groups try. But with the addition of mesh features, Bluetooth is becoming a significantly better option for smart home devices. And thanks to its name recognition and already popular use, there’s a real possibility that Bluetooth will start to push out the smaller mesh standards that are already in use."