StandardsMetricsTransmission ModeTransmission Media

Network StandardizationWhos Who in the Telecommunications WorldWhos Who in the International Standards WorldWhos Who in the Internet Standards World

ITUMain sectorsRadiocommunicationsTelecommunications StandardizationDevelopmentClasses of MembersNational governmentsSector membersAssociate membersRegulatory agencies

IEEE 802 StandardsThe 802 working groups. The important ones are marked with *. The ones marked with are hibernating. The one marked with gave up.

Metric UnitsThe principal metric prefixes.

Simplex

Half-Duplex

Full-Duplex

Transmission MediaMedia carries transmission signals Guided wire/fiber/coaxial cable Unguided wireless (radio/infrared/microwave)Characteristics and quality of a data transmission is determined by the characteristics of the medium and the type of signal used.For guided, the media is more important in determining the limitations of transmission.For unguided, the bandwidth of the signal produced by the transmitting antenna is more important than the medium in determining transmission characteristics.Key concerns are data rate and distance

Design Factors related to the transmission media

Bandwidth of mediaHigher bandwidth gives higher data rateTransmission impairmentsAttenuation/distortionInterferenceNumber of receiversIn guided media (not a factor in unguided)More receivers (multi-point) introduce more attenuation

8/1/03Chapter 4: Transmission Media*Electromagnetic Spectrum

Chapter 4: Transmission Media