Network Motifs

A REVIEW is given of some of the international technical standards activities and Recommendations of the International Radio Consultative Committee (CCIR) for radio communications. A new Recommendation for the digital coding of television signals provides a basis for a single world standard for video signals in broadcasting studios, recording, and exchange of programs. Work is underway on high-definition television and a standard for satellite direct broadcasting downlink. Fixed satellite earth-station antenna standards (developed earlier), and performance criteria for satellite links in the integrated services digital network are being improved. Digital microwave radio relay standards include allowable bit error ratio, channel arrangements, and baseband interconnection. Mobile service Recommendations include system standards for VHF/UHF automated radiotelephony, a future global maritime distress and safety system, and radio paging codes and formats. Standards for the use of ARQ in HF and maritime communications, and the use of Universal Coordinated Time (UTC) in international telecommunications, are based on CCIR Recommendations.