Published on June 19th, 2019 📆 | 4993 Views ⚑0
6 Keys to Choosing Between WiFi or a Hub for Connecting Your Devices
If you want to make your home smarter, the first step is to choose a platform for connecting your smart devices. The choices are simple, but the decision may not be.
The simplest and least expensive approach is to use WiFi, a point-to-point wireless technology that consists of a router connected directly to a modem, along with a series of satellite nodes or modules placed around your home to provide complete coverage. The router shares data and enables all the devices on your network to communicate with each other, typically using a 2.4 GHz radio frequency (5 GHz for older routers). You are probably already using WiFi to provide access to the internet and streaming television.
The other option is to set up a hub to control your devices. For those who choose this option, Z-Wave and Zigbee are the dominant protocols and control most of the market. Both Z-Wave and Zigbee operate as mesh networks in which all nodes are interconnected and work together to route data efficiently. Mesh networks self-configure, distributing workloads dynamically. Their greatest advantage is that as you add more devices, your connection actually becomes stronger.
Range and Compatibility
For most people, WiFi is sufficient. You can add devices to what you already have at a low cost without buying any additional equipment.
However, if you want a truly smart ecosystem that can control your home’s temperature, lighting, security, audio, video and more, a hub may be necessary. While WiFi can connect, at most, a dozen or so devices into a network, Z-Wave and Zigbee can each connect more devices than you’re likely to ever need.
Zigbee can handle as much as 65,000 nodes, while Z-Wave can handle 232 nodes. A node is a connecting point (or “touch point,” since it’s wireless). Connections to smart devices, bridges, and switches are all nodes, so the number of nodes needed can add up.
Z-Wave and Zigbee have limitations, however. If you choose Zigbee, there are significant range limits. For Zigbee to function, all devices must be within a range of about 35 feet. Z-Wave has a range of 100 feet, while WiFi’s range is about 150 feet (although range extenders can increase that number significantly). In addition, when Z-Wave or Zigbee is used, all devices in your network must be compatible with your chosen platform.
WiFi is a communication standard. It’s based on technology that is continuously improving. Companies throughout the industry are constantly introducing new products designed for WiFi use.
Z-Wave is a proprietary protocol created by Zensys and now owned by Sigma Designs. Z-Wave offers both forward and backward compatibility, meaning that it’s compatible with all Z-Wave devices, including those no longer on the market. Sigma Designs also plans to keep it compatible with products that haven’t been launched yet, although that is subject to change. Other companies make products that are compatible with Z-Wave, but your choices for home automation will be limited to those products.
Zigbee compliance is more limited, as all devices must be certified compliant by the Zigbee Alliance, an association that includes promoters (e.g., Amazon and Comcast); participants, who are developing compliant products; and adopters, who receive access to Zigbee standards and specifications. Gaining certification from a standardization board is an added expense and takes time, so some manufacturers avoid it.
It’s possible to connect devices that are not compatible to your hub but doing so will require additional hardware and working around the compatibility issue can be difficult and frustrating.
A hub provides a common connection point for all devices in a network. It’s a central location for monitoring and managing all your electronic devices, so you can check and adjust everything according to your needs.
A hub can provide total control, while the ability for your devices in a WiFi system to communicate with each other is limited. Specific instances may not make much difference; it shouldn’t matter whether your smart garage door opener can communicate with your smart audio system, for example. But the ability for all devices to communicate with each other can be advantageous.
Let’s say you connect a water-leak sensor to your hub. You may have the ability to communicate with a smart water valve, so you can remotely shut off the water that is causing the leak. However, this involves extra cost (for the shutoff valve), set up time, and potential technical problems. Most water leaks are very minor (versus exploding pipes) and can wait a few hours to be addressed. In the case of a real emergency, it’s likely you can get a neighbor to go shut off the water, as many people have a key to their neighbor’s house.
Cost is another advantage of WiFi; everything runs through your router, so there’s no need to buy a separate hub or any other equipment. A hub can be relatively inexpensive, typically costing $50 to $150 (although the more functionality you’re looking for, the more you’re going to pay). It also costs less to develop smart products that work with WiFi than to make products compatible with Z-Wave or Zigbee, so there are more of them and they typically cost less than Z-Wave or Zigbee compatible devices.
You may have to purchase a higher quality router than the one provided by your internet service provider. In addition, WiFi uses more power than either Z-Wave or Zigbee. All devices in your WiFi network will need an ongoing supply of power or strong batteries (although many manufacturers of WiFi devices have put growing emphasis on increasing battery life).
Z-Wave is a low-power technology and Zigbee uses even less power. Both will use less power than WiFi and your batteries will generally last longer.
The more devices you connect to your WiFi router, the slower your connection may become. Most devices send infrequent commands that use little bandwidth, but some activities require significant bandwidth and can slow your WiFi down. Conversely, with a mesh network, the more devices you add, the stronger your connection becomes.
Another advantage of WiFi is that it is more difficult to hack into than a hub-based system. Devices on your WiFi network typically connect to the router only once or twice a day. A hacker would have to know when the connection takes place to hack into it.
Conversely, a completely wired smart home hub presents far greater opportunities for hacker mischief. Someone can hack in at any time and gain control over your home, silencing your alarm system, unlocking doors, and more.
Last year, Ken Munro and Andrew Tierney from Pen Test Partners found that they were smarter than the smart locks they tested that used the new Z-Wave S2 standard. They found decrypting the Z-Wave S2 standard to be “trivial,” as it could easily be downgraded to the previous Z-Wave S0 standard.
Zigbee is less secure than Z-Wave, because Zigbee does not require active confirmation when pairing a device. With active confirmation, the user presses a button on the hub to pair a device, and a button on the device to send out a signal authorizing the pairing. Without active confirmation, unwelcome users can gain access to your wireless protocol.
If you already have WiFi, you can keep your network intact and create a separate hub for any new devices, but you’ll need to be certain that they don’t interfere with each other.
Z-Wave and WiFi operate on different frequencies, so your Z-Wave hub won’t affect your WiFi network, regardless of how many devices you have on it. Of course, the devices on your WiFi network won’t be able to communicate with the devices on your Z-Wave network, but that may not matter to you. Zigbee, though, uses the same radio frequency as WiFi – 2.4 GHz – so they will likely interfere with each other.
WiFi, Z-Wave, and Zigbee are all well-established and continue to evolve. WiFi has been available since 1997. Z-Wave was introduced in 2001, initially for businesses that needed to connect many devices to a network. Zigbee became standardized in 2004.
Analyst firm Gartner predicts that products and services based on the Internet of Things (IoT) will generate $300 billion revenue by 2020, with sales of 26 billion devices. Given that home automation is a rapidly growing market, it’s unlikely that WiFi, Z-Wave, or Zigbee will become unavailable anytime soon.
New protocols are being introduced, but they will have to have competitive advantages to capture significant market share. However, the IoT is still in its early stages and a significant breakthrough could produce a new market leader.
So which protocol should you use? Your decision may be based on personal preference. If you’re a person who likes to have the latest technology and the smartest home in your neighborhood, you’ll likely want a hub solution. If you want the simplest and lowest cost solution, WiFi should be more than adequate to serve your needs.