Going significantly beyond the capacity and geographic reach of current cellular LTE coverage in cities requires to bring the cells to where the people are: Inside buildings. From a technical point of view small cells could do the job, they are now small enough to be installed just about anywhere. From a practical point of view, however, there are a number of major problems with that.
Competition Won’t Work Indoors
While I strongly believe in the current approach to have three or four network operators compete on the cellular macro level to achieve good coverage and capacity, this is unlikely to work indoors. This is because owners of large buildings such as shopping malls, cinemas, or even individual shops like restaurants and cafés are unlikely to be willing to install separate small cells of each network operator.
A way around this could be that all network operators that are interested in providing indoor coverage in a building share the same small cell. Again the technology for this is there, it can be done with MOCN. The problem with this is, however, that there is no competition and hence there will be only little incentive for network operators to spend money on a shared small cell and operating it. Also, when the small cell goes down there is no incentive to repair it quickly as all operators are down at the same time and hence, there is no business opportunity to be better than the others. In practice such problems are present today already, e.g. when common tunnel coverage fails.
Another issue is who will pay whom!?: Will network operators ask building owners to pay for the privilege to get in-house coverage, will building owners ask mobile network operators for the privilege to install coverage inside their building or will both be happy to share the costs because in the end they both benefit? I guess in practice this very question is the problem why installing coverage in railway and metro tunnels takes such a long time. For example, I’ve already complained back in 2013 that there is no UMTS or LTE coverage in the Paris metro and things haven’t gotten much better since. And Paris is by far not the only city where nothing seems to be moving. It’s a disgrace!
Alternative Approach – Wifi
Perhaps an alternative approach is required indoors as has also been suggested by William Webb in his book “The 5G Myth”: Wifi. The problem here is that the current approach is not seamless and not ubiquitous. Most venues offering Wifi today require users to sign-in and, in addition, often reserve themselves the right to track who’s coming and going and some even use the opportunity to insert advertisement in web pages that are still sent in the clear. In other words we’ve got a bit of a privacy issue here. Another problem is that such Wifis are usually not encrypted as this would require the user to know and enter a Wifi password the first time a network is used. Another thing that makes the process even more painful.
Eduroam(-like) Authentication To The Rescue!
Much better would be a universal sign-on mechanism. Sounds complicated? Well it is not at all and one flavor of such a system is already widely popular in academic circles: Eduroam. Eduroam allows devices to seamlessly use Wifi networks around the world, mostly at universities but also in places such as airports in Sweden and Norway!
Apart from being seamless and easy to use on notebooks and mobile devices, it is a distributed authentication system. Each organization such as a University that uses Eduroam has its own authentication server for its members (e.g. their students, staff, researchers). When an Eduroam user roams to another place that also offers Eduroam, the Wifi system detects that the user is from another institution and automatically forwards the authentication request there. Nothing has to be changed in the Wifi settings of mobile devices as authentication is based on Wi-Fi WPA2-professional that is supported by all PC and mobile operating systems today. A great and totally seamless system that works wonders in practice as I can personally attest as I’ve been using Eduroam access all over the world for quite some years now.
While authentication is distributed, Internet access is localized. This means that after authentication, the user is granted access to the Internet locally, there is no data roaming unlike in mobile networks.
The big question here is how such a universal and global authentication system could be set up? Or perhaps the use of Eduroam could be extended for this purpose? I guess in practice it will take many years before these ideas are be further explored because the mindset that we have a problem here and that an unconventional approach is needed to solve it is not really there in the industry and in governments at the moment.