GPRS for Mobile Internet

U

UDP/IP path protocol, 105

UL-UNITDATA message, 295

Unconfirmed information (UI) frames , 357

Uniform resource locators (URLs), 48

Unrestricted digital information (UDI), 9

Update

cell , 328

combined RA and LA, 330-32

GPRS parameter, status, 334-35

inter-SGSN RA, 329-30

intra-SGSN RA, 329

normal RA, 329-30

RA, 328-29

radio access capability, 297

UPDATE PDP CONTEXT REQUEST message, 347, 348, 349

Uplink

adaptation, 267

multiplexing, 260-62

state flag (USF), 80, 81

Uplink power control, 115-18

closed-loop, 116, 117

open -loop, 116-17

parameters summary, 118

performance methods , 115-16

See also Power control

Uplink TBF, 78, 208

ACK/NACK request period, 264

contention resolution procedure, 226-29

modification, 225-26

release, 246-47

RLC data block transfer during, 241-43

Uplink TBF establishment, 209-29

access persistence control, 212-13

access request, 209-12

on CCCH, 213-19

on PCCCH, 219-24

RACH/PRACH phase, 209-13

trigger, 209

when downlink TBF is established, 224-25

See also Radio resource allocation

User datagram protocol (UDP), 66, 105

User plane, 355-87

GTP layer for, 380

interworking with external networks, 383-87

IP packet sending within GPRS PLMN, 381-83

packet transmission between MS and SGSN, 355-80