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THE CPD ZONE
HOW DOES A NETWORK WORK? Geoff Meads, Network School Trainer for CEDIA, looks at how networks are configured and operate and explains why they’re the bedrock of a quality smart home installation. hen you think about a ‘smart home’, what do you imagine? Maybe it's a huge property with fancy lights, piped music, and a TV in every room? Perhaps there’s a sophisticated security system and curtains that open and close automatically? Even the most modest view of a smart home might include a video doorbell, wireless speakers and maybe a ‘smart’ thermostat. Whichever type of installation comes to mind, it will have one common technology as its backbone – an IP network. Once only found in the world of corporate IT systems, the IP (Internet Protocol) network found its way into homes with the introduction of internet access in the late 1990s. For many people, it’s just known as ‘the Wi-Fi’, an anonymous black box in the corner of a room downstairs or by the front door. Nowadays, a huge amount of pressure is put on this little black box, especially with the introduction of mobile devices and internet-based TV systems like Netflix, YouTube and BBC iPlayer. Because home networks are now so ‘busy’, venturing into smart home
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technology without IP networking knowledge is like trying to do electrical work without knowing your ‘twin and earth’ from your RCD. You might be able to make a guess as to how it all works, but disaster won't be far away without a bit of education underpinning your work. What is a network? So, what is an IP network? We can think of a network as an interconnected collection of devices. However, unlike simple point-to-point connections like traditional audio and video cables, network connections are different: they offer two-way communication, they split transmissions up into smaller chunks (rather than a continuous stream of data) for transmission, and information can travel through many other devices before reaching their destination. The way network traffic moves can be understood by looking at the patterns that devices form when they’re connected together. First is a ‘bus’ network. Just like busses on roads,
48 September 2024 PROFESSIONAL ELECTRICIAN
data can be exchanged along a common ‘road’. The ‘road’ can be a cable but, in modern times, the most common bus network is Wi-Fi, which uses the air around us as the ‘road’. The second pattern we find is called a ‘star’ network. Much like a roundabout, a star network uses a single, central point to bring several roads together, so traffic might move from one road to another in order to reach its final destination. Finally, we have a ‘mesh’ network. These are a little more complex, as each device has multiple incoming and outgoing connections. A full explanation of a mesh network is beyond the scope of this article but is covered in many network courses.