[U]

U-M IT Communications Advisory Committee – A committee with cross campus representation that makes recommendations to IT Communications Services on product direction.

U-M Backbone Interconnect Network(UMBIN) – The network which attaches Ann Arbor campus backbones to each other and the Internet.

UMnet – The portion(s) of the University of Michigan data network administered by ITD. At this time it includes the ITD FDDI Backbone, ITD Off Campus Backbone and UMBIN.

UMnet Admin – UMnet Administration. The ITD group that administrates UMnet.

Unattended operation – Transmission and/or reception that is controlled automatically and does not require a human operator.

Uniform call distributor (UCD) – Device located at the telephone office or with a PABX which distributes incoming calls evenly among stations or agents.

Uniform service order code (USOC) – Information encoded for billing purposes by the local telephone company; typically used on service orders and service equipment records.

Unipolar – (1) Neutral transmission of teletypewriter signals, where current indicates a mark and no current means a space signal. (2) Logical opposites are represented by the same electrical voltage polarity.

Universal product code (UPC) – Printed bar-code label format on product packages.

Usage – (1) Measure of trunk or equipment occupancy in telephone traffic engineering. [One trunk busy for an hour carries one erlang of traffic. Usage is measured in CCSs (hundred-call seconds) where 36 CCS per hours = one erlang.] See erlang.

Usage sensitive pricing (USP) – Charge for service based on the amount of use.

Usage sensitive service – Pay-for-what-you-use method of charging for local calls.