The increasing WiFi oversupply does not provide more, but less power. Sebastian Richter, Senior Product Manager Operator Solutions at devolo explores the contribution that powerline and WiFi solutions can make.
Take a look at the available WiFi connections on your smartphone. The chances are, it’s a long list. Particularly in urban environments, it is not uncommon for dozens of different SSIDs (Service Set Identifier networks) to be competing.
Sometimes, this can be amusing. Neighbours are liable to give their networks entertaining names – many of us have lived near a ‘Martin Router King’ or a ‘LAN Solo’. But there are some unfunny potential consequences of the WiFi boom.
Heat maps of many large cities and urban areas show an oversupply of WiFi access points. Consider wigle.net, which provides a colour-coded overview of WiFi networks worldwide. Most urban areas display an astonishing density of routers and WiFi access points, appearing on screen as a thick sprinkling of purple dots. Entire city districts are illuminated several times over with wireless networks, colour-coded yellow throughout for the highest possible level of network density. Ultimately, because all of these networks transmit on the same frequency bands, there is a growing danger of so-called ‘WiFi infraction’
It is important to understand that these high levels of density are not just caused by professional WiFi, but also by private households upgrading their domestic networks with increasingly powerful routers, multiple access points and vast numbers of devices. After all, the average household now features multiple smartphones, tablets, laptops or desktops, connected entertainment systems like TVs or multi-room loudspeaker systems, and smart home equipment like intelligent kitchen equipment, security systems and smart meters. Consumers want to use this ever-increasing number of WiFi-enabled devices at the same time, and with increasingly high bandwidth demands.
This results in two core challenges: delivering high-speed, high-bandwidth WiFi throughout the home and ensuring that as many devices as possible can be used simultaneously.
Network coverage: More isn’t always helpful
Even now, a common challenge is for households to experience good WiFi coverage in some parts of their homes, but not everywhere. In response, many users are distributing ever more access points throughout their homes, thanks to new mesh systems. If their own WiFi weakens, perhaps because of concrete walls or reinforced ceilings blocking the signal, they simply add another access point.
But many purely WiFi-based mesh systems are dual-band systems that use the 5 GHz band for both data transport and coordination between individual access points – and this affects the performance and slows down the WiFi.
Even worse, the signal quality can actually deteriorate if many users in the neighbourhood use the same technique. As we have seen, WiFi network density in urban environments is already substantial. If three or four routers send signals on the same channel and work with three to four separate SSIDs, the traffic overhead for SSIDs alone can be as high as 50%. As a result, the air interface no longer offers sufficient capacity or time slots and the WiFi becomes slow for all users. They could change channels, but not all devices support every channel.
In addition, in Europe there are only three channels in the 2.4 GHz band that do not overlap, and only four in the 5 GHz band that support each device and for which there are no limits.
Simultaneous use of many terminals
Additionally, the more WiFi-enabled devices are used in the house, the more are used at the same time. The current WiFi 4 and 5 standards therefore have an increasing problem, especially because channel management via OFDM (Orthogonal Frequency Division Multiplexing) blocks a channel completely by the data transmission of a client, regardless of the size of the transmission. The new WiFi 6 standard will improve matters, because it uses the channel management method OFDMA (Orthogonal Frequency Division Multiple Access) and improved Multi User MIMO to ensure that more terminals can send and receive data at the same time and at higher speeds.
However, WiFi 6 has still not been fully adopted, and the first routers and WiFi 6-enabled terminals are only just coming onto the market. According to experts, it will still be a few years before WiFi 6 it reaches the mass market – and millions of WiFi 4 and WiFi 5 devices are still being sold today.
Less is more: Powerline as an intelligent solution
What, then, is the best way forward?
One solution is to combine powerline technology (PLC) with WiFi, because this enables a genuinely ‘more with less’ approach. With just a fewer powerline/WiFi devices, complete network coverage from the basement to the roof of a building can be achieved. Data is transmitted along a physical powerline to where each access point is required, meaning that ceilings and walls are no longer an obstacle, and additional mesh satellites are, for the most part, rendered superfluous. Ultimately, fewer satellites means less ‘digital air pollution’ – and less chance of a WiFi meltdown thanks to a drop in performance.
The current generation of G.hn-based PLC products is advancing into new speed dimensions. According to our analysis, 90% of our PLC-based connections achieve data rates that are necessary for bandwidth-intensive 4K virtual reality applications, for example. As bandwidth-hungry games and multimedia entertainment become the norm in homes all over the world, it will become increasingly important for consumers to look beyond mesh systems and multiple access points to power their home networks.