U

UA (User Agent), 320

UDP (see User Datagram Protocol)

UE (see User Equipment)

U-interface (DSL), 138,139

UMA (see Unliscensed Mobile Access)

UMTS (see Universal Mobile Telecommunications System)

Uncertainty, 9–13

calculation of, 12–13

in cellular networks, 4–6

and confidence, 10–12

defined, 320

in emergency services, 12,13

FCC standard for, 13

graphical representation of, 10f

in PIDF-LO, 38–46

Unified presence model:

for Geographic Location/Privacy, 35–37

for presence service, 35–36

Uniform Resource Identifier (URI):

defined, 320

and device callback, 320

fragment identifier, 292

in presence documents, 28

in wireless data networks, 208

Uniform Resource Locator (see Uniform Resource Identifier)

Uniform Resource Name (see Uniform Resource Identifier)

Universal Mobile Telecommunications System (UMTS):

defined, 320

GPRS for, 196

Universal Plug and Play (UPnP), 92–93, 320

Unliscensed Mobile Access (UMA), 203–205

Base Station Controller in, 203

in GSM, 203–205

Mobile Switching Center in, 203

Uplink TDOA (U-TDOA):

and ALE overlay, 191

defined, 320

UPnP (see Universal Plug and Play)

URI (see Uniform Resource Identifier)

URL (see Uniform Resource Identifier)

URN (see Uniform Resource Identifier)

Usage-rules,47-48

User Agent (UA), 320

User Datagram Protocol (UDP):

defined, 320

and DHCP relay, 109

User Equipment (UE):

defined, 321

in IMS emergency sessions, 210

User identity:

from access provider, 247–248

assertation of, 80–82

in cellular networks, 247

in HTTP Enabled Location Delivery, 80–82

User-entered location, 224

U-TDOA (see Uplink TDOA)