The GSMA Mobile World Congress is a combination of the world's largest exhibition for the mobile industry and a conference featuring prominent executives representing mobile operators, device manufacturers, technology providers, vendors and content owners from across the world. The event, initially named as GSM World Congress and later renamed as the 3GSM World Congress, is still often referred to as 3GSM or 3GSM World.
The GSMA Mobile World Congress currently takes place in February at the Fira Gran Via venue in Barcelona, Catalonia, Spain. The annual attendance is generally between 60,000-70,000 people. Up until 2006 the event took place in Cannes and was known as 3GSM World. Attendees represent more than 200 countries from across the globe.
GSMA Mobile World Congress 2013 took place between February 25 and February 28, 2013. The theme was The New Mobile Horizon and was attended by more than 72,000 participants.
More info: http://en.wikipedia.org/wiki/Mobile_World_Congress