Telecommunications networks based on synchronous 64 kbit/s channels are too restrictive for the future realisation of integrated broadband networks. New switching and transmission techniques, particularly those based on asynchronous transfer modes (ATM), are required. Roke Manor Research Ltd. and Plessey Research Caswell Ltd. are actively developing these new techniques at a system and technology level under the auspices of the European Commission's RACE programme. The paper introduces the issues pertinent to ATM, highlighting the system and technology aspects of the work being carried out within a RACE project entitled 'Broadband Local Network Technology' (BLNT) and also describes previous ATM work relevant to the current research activities.