The typical way that Ethernet, HomePlug, Wi-Fi and similar network infrastructure technologies are marketed by their adherents is that they have to be the only or primary link technology for your network. This also includes the market expectation of a network-enabled device like a BD-Live Blu-Ray player having to be equipped with Wi-Fi connectivity as the preferred connection means for example. In some cases, this leads to certain technologies being sidelined when it comes to providing support for them in a network product or standard.
How I see the different infrastructure technologies is that they complement rather than compete with each other. This is because each of the different technologies have strengths and weaknesses that suit particular situations and applications.
For example, Category 5 Ethernet is able to sustain very high link speeds and bandwidths but requires new cabling to be laid. It may suit the creation of “arterial data links” as part of electrical works that are performed when you build or renovate a house or similar building. This also includes inter-building data links that are put in place when an outbuilding like a bungalow or barn is constructed or wired for electricity.
Another example is that Wi-Fi wireless networks have the inherent advantage of being wireless and working with devices that are inherently portable like laptops, tablet computers and smartphones. The main disadvantage with this technology is that it is radio-based and signal quality can suffer due to the relative position of the access point to the client device.
Yet another example is HomePlug AV which uses a building’s AC wiring. This has limitations with interference generated by particular appliance types and doesn’t yield the highest network speed. But it has the inherent advantage of the power outlet being a network outlet, thus allowing for increased location flexibility for network devices without the radio-reception hassles that Wi-Fi has.
When I work out what technologies to use in a network, I would make sure I use a “new wires” and/or “no new wires” wired backbone technologies alongside one or more Wi-Fi wireless segments. For example, if I wanted to save data wiring costs on a new building or renovation by cutting back on Ethernet outlets, I would make sure that there is an Ethernet link that reaches each end of the house or between floors of a multi-storey house. As well I would then keep a pair of “homeplugs” on hand to provide wired network connectivity to parts of the house not reached by the few Ethernet outlets. This would work alongside a wireless router that is working at the network’s Internet “edge” connected to the Ethernet and HomePlug segments. This would also mean that if there isn’t adequate wireless coverage through the premises, I could deploy a wireless access point in the “dead zone” and connect it to the Ethernet or HomePlug segment as a backbone.
So this is why I would not stick with one particular network-infrastructure technology for a home network but would suggest the use of a mix of different technologies that use different media. It is also why I suggest and advocate on this site network setups that use one or more of the different technologies.