LAS VEGAS, Nev. - Manny Pacquiao and Floyd Mayweather hadn't even decided how much it would cost home viewers to watch their fight when the head of the Nevada Athletic Commission started planning security for their big bout.

Five times in the 10 weeks since the two welterweights set a date for their long-awaited fight, commission chief Francisco Aguilar has convened state, federal and local police, fire, tourism and fight officials for one thing: to keep hundreds of thousands of people outside the ring safe.

Boxing, particularly in big matches like this one, poses a special challenge to Las Vegas officials.

"We're not preparing for a fight night. We're preparing for a fight week," Deputy Las Vegas Police Chief Gary Schofield said, pointing to a series of events, including Friday's weigh-in at the MGM Grand hotel. As a security and crowd-control measure, advance tickets ($10 face value) will be required for the first time.

He described a security plan of concentric circles.

The Athletic Commission handles security inside the ring. The hotel and police have responsibility for the arena and hotel, which is Las Vegas' biggest, with 5,005 rooms.

Police, along with state and federal agencies, are in charge outside — "all the way out to the airport, Interstate 15 and the neighbourhoods," Schofield said.

"The overall goal is to maintain the integrity of the event," Aguilar said. "Las Vegas is a brand. To protect the brand, you have to protect the event."

Fight nights haven't always gone so smoothly.

In 1993, "Fan Man" James Miller guided his powered parachute to land next to a Caesars Palace outdoor ring where Evander Holyfield and Riddick Bowe were brawling. Ringside fans and security pummeled Miller, who was arrested for the stunt.

In 1996, rapper Tupac Shakur was killed in a drive-by shooting after Mike Tyson knocked out Bruce Seldon at the MGM.

In 1997, bedlam erupted inside and outside the ring when Tyson was disqualified for biting Evander Holyfield's ears. Thousands of people stampeded through the MGM Grand hotel lobby.

Last year, a scuffle in the elbow-to-elbow crowd leaving a Mayweather-Marcos Maidana fight — and a loud noise that officials blame on a partition falling to the floor, not a gunshot — spurred a panicked stampede in a food court area outside the arena. Officials said about 50 people were treated for minor injuries.

"We've had times when it doesn't quite go according to plan," Schofield acknowledged. "We've learned."

Officials won't say much about the details of how they'll protect the scene and the army of celebrities in town.

But Deputy Clark County Fire Chief Erik Newman said about 300 firefighters in his department will be on duty or stand-by.

"I think we'll have the most millionaires and billionaires in one place in the country," Newman said.

The Las Vegas Convention and Visitors Authority reported last week that virtually all 150,000 hotel rooms in the city were sold for fight weekend.

Las Vegas police have almost 2,500 sworn officers. They'll get help this week from the Nevada Highway Patrol, neighbouring Henderson and North Las Vegas police, and federal agencies ranging from the FBI to the Department of Homeland Security.

"We're a community that knows how to handle large events," Schofield said. "We do them a lot."

Indeed, Las Vegas draws 340,000 people for its annual New Year's Eve fireworks party on the Strip, 200,000 to a weekend-long Electric Daisy Carnival and almost 120,000 for a NASCAR race.

Tim Jeffery, vice-president of security for the MGM Grand Hotel & Casino, said fight fans and tourists will notice lots of security officers in bright yellow-green shirts on pedestals, but won't see behind-the-scenes preparation.

Ticket-holders won't be able to bring bags or backpacks and will pass through metal-detectors, Nevada Athletic Commission Executive Director Bob Bennett said.

People without a fight ticket will be cleared out of the shopping area between the arena and casino. Afterward, ticket-holders will be directed out of the arena through the closest door to their seat.

Newman, the deputy fire chief, said he sees after-fight events and overcrowding at clubs and hotels as the biggest security challenge.

"There will be a lot of people outside," Bennett said. "The access to alcohol and partying around town could create some turmoil."