free space

1. A theoretical region of space utterly devoid of physical matter, gravitational fields, and electromagnetic fields. 2. A region devoid of physical obstructions that might hinder the propagation of electromagnetic signals. See also free space transmission.

• ultra high frequency (UHF)
• ultralong wavelength band (U-Band)
• ultraviolet (UV) light
• UL (Underwriters Laboratories)
• UMA (Unlicensed Mobile Access)
• UMTS Terrestrial Radio Access Time Division Duplex 1.28 Mega chips per second Option
• UMTS (Universal Mobile Telecommunications System)
• unbalanced
• Unbundled Network Elements Platform (UNE-P)
• Unbundled Network Element (UNE)
• unbundled service
• underground cable
• Underwriters Laboratories (UL)
• undocumented feature
• undocumented feature
• (UN/EDIFACT)
• UN/EDIFACT (United Nations/Electronic Data Interchange For Administration, Commerce,
• UNE-P (Unbundled Network Elements-Platform)
• UNE (Unbundled Network Element)
• UNE (Unbundled Network Element)
• unibit
• unicast
• unicast address
• Unicode Consortium
• Unicode Transformation Format (UTF)