Will Sony march away from mobile?

It is one of the best known names in consumer electronics, the firm which brought us the Trinitron TV, the Walkman and the PlayStation - and of course it has a huge presence at the Mobile World Congress trade fair.

But it's now worth asking the question: Why is Sony still making mobile phones? Because it really isn't working.

Sony makes perfectly nice, rather classy Android phones.

One of the stars of this year's MWC, Pebble Watch founder Eric Migicovsky, told me you'd have to prise his Xperia from his cold dead hands.

Sony has launched another good-looking, though unremarkable phone and an ultra-slim tablet in Barcelona. What it has failed to do is make any real impact on the market.

Sony's M4 Aqua has a plastic rather than metal casing to make it cheaper to manufacture

Two years ago, when I met Sony chief executive Kazuo Hirai at this event, he was bullish about claiming at least the number three spot in the smartphone market.

But after briefly making progress in some European countries, Sony is now counted amongst "others" in research firm IDC's figures on market share, way behind Samsung and Apple, and overtaken by three Chinese firms.

What's more, its mobile division is a major factor in huge losses at Sony.

So, when I met Mr Hirai again, I gently suggested that it might be time to give up. He wasn't having it - not yet, at least.

"It's fair to say it's a very dynamic, competitive and rapidly changing market," he told me, admitting that in some areas, "we just couldn't keep up."

He went on: "We need to keep a closer eye on the return on capital, what the competition is doing... But that's not to say we're getting out of the business."

Sony has also been throwing good money after bad when it comes to wearable technology, launching smartwatches and intelligent fitness bands with gay abandon.

Kazuo Hirai pointed at his own band as we sat down for our interview and insisted it was delivering all sorts of useful data, revealing, for instance, that he never sleeps well on Wednesday nights.

(I pondered whether Thursday was the day when he had to tell board meetings how much more money had been wasted on devices that few are buying.)

But he argued that nobody had made a breakthrough wearable device yet and that the market "is still trying to figure out what actually is the product that resonates with customers".

Sony is testing a new pair of smart glasses, modelled here by Rory

Having had a quick go with the prototype Sony Smart EyeGlass, I can confidently predict that this won't be that product.

It makes Google Glass look stylish - and its technology already feels very last year.

A few weeks ago, Kazuo Hirai tacitly acknowledged that mobile technology was not key to Sony's future, betting instead on the company's entertainment division as the engine of future growth.

Sony Pictures may have been a source of huge embarrassment when its secrets were laid bare in a hacking attack - but movies still look an easier way of making money than mobile phones.

In his two years at the top, Sony's amiable chief executive has already shown that he can be ruthless when necessary and that's helped the share price, if not the profits, recover.

Sony's Xperia Z4 Tablet is the latest in a line of waterproof gadgets from the firm

I asked him whether he could guarantee Sony would still be in the mobile business five years from now.

"There is no guarantee that we will be in any business in five years' time," he responded.

"That's just the nature of the electronics business."

Five years ago, Nokia and Blackberry were two huge, even dominant forces in mobile phones.

Now one has gone and the other is barely visible.

Don't be surprised if Sony does not turn up at the 2020 Mobile World Congress.