There are 6 core networking technologies used in the modern smart home:
Ideally, you would try and minimise the number of technologies in your home but, you will struggle to avoid using these five in practice. The main reason to focus on one single mesh-networking technology, is to ensure you have a mesh network with enough nodes to work reliably, providing diverse routing paths through it and to ensure all nodes are well connected.
With all wireless networking technologies, you will eventually reach its limitations in terms of bandwidth, latency and the number of devices supported though.
In most home, you are going to be already using Ethernet cables and Wi-Fi but how you use these networking technologies is really important.
The main choice is deciding between ZigBee and Z-Wave for the connection of battery-powered sensors and for control of lighting and appliances. In reality, even if you choose to focus on using Z-Wave in your smart home (as we have done), you will quite likely end up using ZigBee in some form. As an example, we use some Philips Hue lighting in our @smartest_home and this uses ZigBee networking.
It is also very hard to avoid Bluetooth, as it is used on Smartphones and tablets to connect to wireless speakers, wearable technology, vehicles, etc. There are some manufacturers of smart home sensors and devices also using Bluetooth too.
By far the most important aspect of Internet connectivity for most people is its speed but, usually this is because they don't have enough! With the advent of fibre-based broadband connections in the UK, many people do get a fast Internet connection but coverage in many rural areas is still lacking. Many people are still reliant on ADSL technology and for some 4G is a better option (5G still has very limited coverage)
In some countries Internet Service Providers (ISPs) are now offering (claimed) Gigabit Internet connectivity (but in reality it is slower than this) but, this is simply a ploy for ISPs to sell you more bandwidth than you need and hence charge you more for a service that you don't really need and can't really use. There are very few applications that can utilise these kinds of speeds and none that are useful to most people. There are many other bottlenecks deeper in the network will be the limiting factor, long before you even get close to these kinds of speeds. Most servers in the network will not deliver content at these kinds of speeds.
Modems, switches, routers, hubs, etc. all require power. This means that if you want to keep the network operating when the mains power is removed (i.e. a power cut), then you need to maintain this power using a Uninterruptible Power Supply (UPS).
There are other networking standards and many proprietary networking technologies used by smart home installers, manufacturers and suppliers:
LoRa.
Wireless Gigabit Alliance (WiGig) is an organisation promoting the adoption of multi-gigabit speed wireless communications technology operating over the unlicensed 60 GHz frequency band. This implies a relatively low power and thus limited range, shorter than current Wi-Fi standards. 10m line of sight is the claimed maximum so far. Introduce barriers and walls and it will be less. It is thus complimentary to Wi-Fi and is certainly not a competitor to 3G and 4G networking. One of the key applications envisaged for WiGig is wireless high-speed video transmission, e.g. wireless HDMI.
WiGig has been designed as a low-power technology and claims to be five times more energy efficient than Wi-Fi. It uses beam-forming to focus the radio beams for best performance, reducing congestion and effectively pointing the radio signal where it needs to go.
There is a very good TED talk on this subject:
Li-Fi has been in the news again (October 2013) after a a team of researchers in China reported that they have successfully created an LED lightbulb that can deliver data as fast as 150 megabits per second.
Power line communication carries data over the cables in your home used to distribute mains power. Power line adapters typically come in pairs. One is plugged into the mains power network near your router and is connected to it via an Ethernet cable. The remote end is also plugged into the mains power network and then also connected to your device using an Ethernet cable. Typically these are often used to network a Set-Top Box (STB) or Personal Video Recorder (PVR). It is possible to use a switch at the remote end, to connect multiple devices. You can use more than two powerline adapters but the standards have evolved over the years and you need to ensure different brands and models are compatible.
Power line can work well in many homes but, it is sensitive to the layout of the wiring, the devices plugged into the power sockets and the electrical filters and circuits used within them. Whilst running technology trials, we have seen many homes where this technology simply will not work or has poor performance. The rated speed of these devices is the maximum theoretical speed possible under ideal conditions. In real-world installations the speeds achieved will be a lot lower than the quoted speed rating.
Some adaptors have a mains pass-through socket, which effectively gives you back the mains power socket that the adaptor would otherwise be occupying.
Do not use the default passwords on powerline adapters. You may well find that your connect to a neighbours network, if they use the same devices and same default passwords.
Network Segmentation is the physical act of grouping devices using switches and other networking hardware to reduce traffic across network segments and improve security. All of our smart home hardware is connected to it's own network segment that can be physically isolated from the Internet by disconnection just one cable.
Another approach is to create a Virtual Local Area Network or VLAN. VLANs allow networks and devices to kept separate whilst sharing the same physical cabling, improving simplicity, security, and traffic management.
Our contextual smart home is also monitoring our home network, looking for devices connecting and disconnecting via wired and wireless technologies. It also models networked devices and tracks how long they have been connected and disconnected. Devices like our TomTom 6200 satellite navigation devices connecting provide useful information and context that can be used to better understand what is happening in and around our home.
