What is Phase Two?

Field tests. These will take place in a football stadium chosen by the technology system provider. Testers will conduct a greater volume of shots on an empty goal, shots against an impact wall, shots on a goalkeeper, and the sled test, also used on Phase 1 testing, where a ball is placed on a sledge and moved along the goal-line. Training sessions . A series of simulated scenarios on the field using players will assess the systems with an increased number of players in and around the goalmouth. Laboratory tests. Both systems will be tested against a variety of conditions. This will include simulating different climatic conditions (including rain, smoke/fog and heat/humidity), testing against the impact of proximity to mobile phone transmitters or other magnetic field distortions (eg TV cameras, LED advertising boards) and tests on the watches which would be worn by the match officials. Real 'live' matches . To ensure that every eventuality has been considered in the two testing phases, each company is also required to have its system tested in two separate 'live' matches.

Goal-line technology gets 2014 World Cup go-ahead

Blatter also insisted video technology was a "necessity" after a controversial incident in England's 1-0 win over Euro 2012 opponents Ukraine helped eliminate the co-hosts. Ukraine forward Marko Devic's shot crossed England's goal-line but a goal was not awarded. Both Goalref and Hawkeye were used at the Club World Cup and have Fifa approval. Goalref works by using magnetic sensors to determine whether the ball crossed the line, while Hawkeye uses a number of cameras. Two German firms are also likely to bid, with the tender expected to be awarded by early April. A Fifa statement said: "After a successful implementation of Goal-Line Technology (GLT) at the Club World Cup in Japan in December 2012, Fifa has decided to use GLT at the 2013 Confederations Cup in Brazil and the 2014 World Cup in Brazil. "The aim is to use GLT in order to support the match officials and to install a system in all stadia, pending the successful installation, and pre-match referee tests."