Vodafone and Irish energy company ESB are to invest €450m in a 100% fibre optic network across Ireland in an effort to make the nation one of the world's fastest broadband countries.The 50:50 joint venture between the two groups, subject to approval from the European Commission, will start rolling out the network across Ireland in the coming months, with the service expected to start in 2015.The network will initially reach 500,000 homes and businesses in 50 towns and deliver a 100% so-called 'fibre-to-the-building' broadband network, offering speeds from 200 megabits per second (Mbps) to 1,000Mbps.Some 43% of fixed broadband customers in Ireland currently receive speeds of less than 10Mbps.Vodafone said that giving them direct access to 100% fibre broadband of up to one gigabit per second "will transform the internet experience of small and medium businesses, remote workers and consumers"."With global internet traffic set to triple in the next five years, the speed and reliability delivered by 100% fibre broadband will ensure Irish customers can lead the digital lives they want."The fibre will be deployed on ESB's existing overhead and underground infrastructure.Anne O'Leary, Chief Executive of Vodafone Ireland, said: "With the number of devices per household anticipated to almost double over the next four years and more bandwidth-hungry services being developed, this new broadband service will enable a whole range of new services to be offered to Irish customers in the future from entertainment, security, teleworking to web-based gaming or home automation."Vodafone's share price rose after the announcement and was trading up 0.8% at 198.7p by 12:47.BC