Zika virus, terrorism, and time differences - how the BBC is gearing up for the Rio Olympics

"One of the things we were warned about a couple of years ago from the World Cup here was that the phone networks are not brilliant, so I may cut out at any moment," the BBC's head of major events tells Business Insider on the phone from Rio.

Dodgy phone lines are just one of a truck load of challenges facing Ron Chakraborty, who is charged with delivering coverage of the world's biggest sports event to millions of Brits in a city 6,000 miles from home.

Much of the preparation for the Olympics is done up to three years in advance. The big stuff involves contingency planning for terrorist attacks and adverse weather conditions, but Rio has thrown up its own particular problems, not least the mosquito-spread Zika virus.

This close to the opening ceremony, Chakraborty is focused on making sure his team of 455 presenters, pundits, journalists, and producers are settled into their accommodation and able to get around the city. "Everything under the BBC's control, we're quite happy about. There are always teething problems with a major event, but it's nothing we haven't seen before," he says.

The BBC's presence in Rio is 40% lighter than it was in London and it is tiny in comparison to NBC, which will flood the International Broadcast Centre at the Barra Olympic Park with more than 2,000 employees (they even have their own McCafé). Not that this means the BBC will be able to cut corners.

Those 455 BBC staff will deliver 3,000 hours of coverage, 500 more than in 2012. TV channels BBC1 and BBC2 are the focal points of the event, but 24 HD live streams of all the major action will be available online and on any device.

Chakraborty explains: "This is our first overseas summer Olympics since London, but we won't have the same size team. It's similar to the size we had in Beijing, but we have still got to meet audience expectations. Everyone is having to work that little bit harder."

BBC Rio 2016 coverage in 'turmoil' over Zika virus.

Not everyone has travelled either. Last week, a headline in The Sun screamed that the BBC's Olympics coverage was in "turmoil" after some staff decided against travelling to Brazil over Zika virus fears. Chakraborty says the story was overstated. 

"We've been very clear with everyone early on, we gave them all the information from the World Health Organisation and International Olympic Committee, and said: 'It is your choice, you can pull out if you want'. It has not been a big issue for us. Single figures of people have said they don't want to risk it," he adds.

In a team that includes big name presenters like Gary Lineker and Clare Balding, the highest profile absentee is BBC sports news correspondent Richard Conway, while the rest are support staff. It is nothing new either. The BBC had to contend with bird flu when the Olympics were in Beijing in 2008.

Chakraborty seems more preoccupied with managing the four-hour time difference between Rio and Britain. It is the first Olympics in a time zone behind the UK since Atlanta 1996 and means that showpiece events, such as the 100-metre final, will not be on air in the UK until the early hours of the morning.

Chakraborty says the BBC has an "old school and a new school" solution. BBC2 will replay all the major sport in real-time from 9 a.m., while the broadcaster's online team will turn around a downloadable Rio Playlist highlights video every day.

But no amount of neatly-packaged summaries will enable the BBC coverage to hit the heady heights of 2012. The London Olympics were the most watched TV event in UK broadcasting history and were widely regarded as a triumph for the BBC.

"It was the happiest time in our BBC lives," reflects Roger Mosey, whose 33-year career at the BBC concluded not long after he was in charge of every aspect of the broadcaster's London 2012 output.

"We got everything working in harmony, whereas usually you've got turf wars with news not doing what sport wanted to do and drama not interested in sport. The Olympics transcended that and it was a very precious feeling."

The BBC also broke new ground in 2012 by launching 24 HD television channels to broadcast all the key action from the London Games. This approach has continued in coverage of other major events, including Glastonbury and Wimbledon, and lives on through the live online streams being planned for Rio.

Mosey, now the master of Selwyn College at Cambridge University, says the legacy of 2012 was "make big events bigger" at the BBC. Chakraborty agrees, explaining that his team talks about giving something the "2012 treatment" in a bid to bring the nation together.

BBC top brass believe this is crucial to keeping the broadcaster strong. It is why management fought hard to cling on to the Olympics beyond 2022 after US broadcasting giant Discovery Communications swooped for the pan-European TV rights last year. 

Chakraborty's phone line in Rio holds out long enough for him to underline this point. "The Olympics is one of our crown jewels, it's a really special event that you associate with the BBC. Getting those massive audiences and bringing the nation together is something only the BBC can do," he says.