Which communication system would you choose for the elevator?
First off:

Just because a company patented a technology doesn't mean it turned out to be a good idea. You have to patent things before you try them out in large scale or on the market. There's a lot of useless patents.

Anyway, the prime considerations for a system of this kind are:


reliability
cost


From the cost perspective, wireless would probably win these days – a transceiver is way cheaper than flexible cabling that can withstand years of operation.

From a reliability point of view, it's actually hard to compete with wired systems, seeing that elevators don't usually fail due to reliability problems in the controls. Overall, they fail very seldom.

However, there's no inherent advantage of cabling over wireless communications – both are subject to adverse effects. Where, in wireless systems, that is mainly interference (and noise), in wired systems, that would be cable wear and things like rodents, water leaks. Both would be suspectible to controller failure on each end.

So, if you'd actually plan to replace the established wired cabling scheme with wireless, you'd be the one in charge of making a very detailed estimate on the outage probability of your two systems. 

Now, reliable wireless is not really a new topic, however, there's not millions of simple devices that have the same operational "run time" as cabled elevator systems. Still, there's modules and standards for robust narrowband communications. I don't see why these wouldn't work here, reliably, too. Spread spectrum, frequency hopping, highly repetitive transmitters would do the job with a "outage probability far below any level of significance". 

It's definitely possible to interfere with a radio signal in a elevator tower, but it's also definitely possible to mess with cables.

In fact, I know there's companies that currently are developing wireless, low-latency, life-critical-quality local links. Their vision is that, through rigorous engineering, you can make a car where the break pedal wirelessly connects to the brake controllers, and it would be at least as reliable as a car where that is done electrically.

I don't really think for a nearly perfect channel such as the elevator tunnel, you should be using relay stations. Multihop doesn't improve reliability here, and distances are relatively short, and you get a line of sight. 

Notice that in industrial productions, there's devices that run around on large floors and communicate with the controller via an antenna running along a slotted waveguide. So it's not really wireless communication, it's more like wired communication using RF to avoid physical contacts that can wear out, or cables that can flex too much and break.


in conclusion: this is an exercise in designing and evaluating reliable systems. It might not be the easiest thing to do for someone without a lot of product design and reliability experience (I certainly wouldn't think I could foresee all relevant risks and assess them; I do understand outage probabilities of wireless communications); so, if in doubt, stick with what is proven to work.