This is a question that I am often asked. It’s understandable, most new smart home products we see advertised are wireless and yet we are still reliant on cabling. So when will everything be wireless? In my opinion never; let me explain.
Never you say!?
Yes, all wireless systems have one common fundamental issue, interference.
Issue 1: Interference
For every signal that is broadcast you add more interference to the area. The first few devices you connect work great but as you add more, issues start to arise. They could randomly drop connection or refuse to reconnect. Sure as WiFi has improved there are new and better ways to handle interference but WiFi is not the only culprit and wireless signals that are not part of WiFi cannot be controlled so easily. ZigBee, Z-Wave and Bluetooth all use the same frequency as WiFi and can cause issues.
Issue 2: Signal
The second main reason is signal strength. Each device connected to a wireless antenna draws a small amount of power from the antenna reducing range. Add more devices and those further away start to have issues, add more boosters and we’re back to the first issue, interference.
Issue 3: Speed
The third issue is speed or more accurately throughput. Imagine that the wireless transmitter is a sprinkler, the water is data and each device is a bucket. The first device you add can have a huge bucket, there’s lots of room. Second, 3rd, 4th devices can still have pretty big buckets so lots of data can reach them. By the time we get to 20, 30, 40+ devices we’ve run out of room, the buckets have to get smaller so the performance of all device suffers. To combat this we add more transmitters to share the load, see issue number one.
Issue 4: Power
Finally, we have the issue of power, to be truly wireless the devices must be battery powered. This is costly, replaceable batteries are very inefficient and environmentally unfriendly. Rechargeable batteries are better but you have more downtime whilst you recharge your devices. And let’s not forget all battery-powered devices must be easily accessible for maintenance. So we fix this by putting a power cable to the device. Wait a minute, now it’s not wireless. If we’re putting power to the device we may as well put data there too and avoid all the issues with wireless.
So where do we go from here?
Wireless isn’t all bad, if managed properly it can be a very easy and convenient way to add smart devices. We just need to be acutely aware that there can be issues and avoid wireless for ‘mission-critical’ areas. The future I think is more reliance on PoE powered devices, these get power from the data cable thus reducing the wiring needed whilst maintaining reliability. There are even gadgets out there that can send data and PoE power down two cores meaning old cabling can be easily repurposed for use with tech (2n 2wire).