Post on 03-Apr-2018
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Enhanced Uplink Dedicated Channel (EDCH)
High Speed Uplink Packet Access (HSUPA)
EDCH Background & Basics
Channels/ UTRAN Architecture
Principles: scheduling, handover
Performance Results
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UMTS Networks 2Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Background
E-DCH is a Rel-6 feature with following targets
Improve coverage and throughput, and reduce delay of the uplink
dedicated transport channels Priority given to services such as streaming, interactive and background
services, conversational (e.g. VoIP) also to be considered
Full mobility support with optimizing for low/ medium speed
Simple implementation
Special focus on co-working with HSDPA
Standardization started in September 2002
Study item completed in February 2004
Stage II/ III started in September/ December 2004
Release 6 frozen in December 2005/ March 2006
Various improvements have been introduced in Rel-7 & Rel-8
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UMTS Networks 3Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH Basics
E-DCH is a modification of DCH Nota shared channel, such asHSDPA in the downlink !!
PHY taken from R99
Turbo coding and BPSK modulation
Power Control
10 msec/ 2 msec TTI
Spreading on separate OVSF code, i.e. code mux with existing PHYchannels
MAC similarities to HSDPA
Fast scheduling
Stop and Wait HARQ: but synchronous
New principles
Intra Node B softer and Inter Node B soft HO should be supported forthe E-DCH with HARQ
Scheduling distributed between UE and NodeB
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UMTS Networks 4Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH Scheduling
UE sends scheduling information
MAC-e signaling
On E-DPCCH: happy bit
NodeB allocates the resources
Absolute/ relative scheduling grants
Algorithms left open from standards
Depending on the received grants, UE decides on transmission
Maintains allocated resources by means of internal serving grants Selects at each TTI amount of E-DCH data to transmit
Algorithms fully specified by UMTS standard
DATA
UE NodeB
UE detects
data in buffer
Scheduling information
Schedulertakes UE for
scheduling
Scheduling grant
Scheduling information
Scheduling grant
Scheduling grant
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UMTS Networks 5Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
UMTS Channels with E-DCH
Cell 1
UE
Cell 2
R99 DCH (in SHO) UL/DL signalling (DCCH) UL/DL CS voice/ data
Rel-5 HS-DSCH (not shown) DL PS service (DTCH) DL signalling (Rel-6, DCCH)
Rel-6 E-DCH (in SHO)
UL PS service (DTCH)
UL Signalling (DCCH)
= ServingE-DCH cell
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UMTS Networks 6Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH Channels
E-DPDCH
Carries the data traffic
Variable SF = 256 2 UE supports up to 4 E-DPDCH
E-DPCCH
Contains the configuration as used on E-DPDCH
Fixed SF = 256
E-RGCH/ E-HICH
E-HICH carries the HARQ acknowledgements
E-RGCH carries the relative scheduling grants
Fixed SF = 128
Up to 40 users multiplexed onto the same channel by using specificsignatures
E-AGCH
Carries the absolute scheduling grants
Fixed SF = 256
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UMTS Networks 7Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Timing Relation (UL)
E-DPDCH/ E-DPCCH time-aligned to UL DPCCH
Uplink DPCCH
Subframe #0
E-DPDCH/
E-DPCCH
3 Tslot (2 msec)
Subframe #1 Subframe #2 Subframe #3 Subframe #4
10 msec
CFN
15 Tslot (10 msec)
CFN+1
0.4 Tslot(1024 chips)
148chips
Downlink DPCH
10 msec TTI
2msec TTI
CFN
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UMTS Networks 8Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
HSUPA UE Categories
When 4 codes are transmitted, 2 codes are transmitted with SF2 and 2 with SF4
UE Category 7 supports 16QAM
E-DCHCategory
Max. num.Codes
Min SF EDCH TTI Maximum MAC-eTB size
Theoretical maximum PHYdata rate (Mbit/s)
Category 1 1 SF4 10 msec 7110 0.71
Category 2 2 SF4 10 msec/2 msec
14484/2798
1.45/1.4
Category 3 2 SF4 10 msec 14484 1.45
Category 4 2 SF2 10 msec/
2 msec
20000/
5772
2.0/
2.89
Category 5 2 SF2 10 msec 20000 2.0
Category 6 4 SF2 10 msec/2 msec
20000/11484
2.0/5.74
Category 7(Rel.7)
4 SF2 10 msec/2 msec
20000/22996
2.0/11.5
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UMTS Networks 9Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH UTRAN Architecture
MAC-c/sh
MAC-d
RLC
RRC PDCP
Logical Channels
Transport Channels
MAC-b
BCH
BCCHDCCHDTCH
SRNC
CRNC
NodeB
DCH
Upper phy
DSCH
FACH
Evolution from Rel-5
E-DCH functionality isintended for transport ofdedicated logicalchannels (DTCH/ DCCH)
MAC-hs
HS-DSCH
w/oMAC-c
/sh
MAC-dflows
MAC-e
MAC-es
MAC-dflows
EDCH
E-DCH in Rel-6
Additions in RRC toconfigure E-DCH
RLC unchanged(UM & AM)
New MAC-es entity withlink to MAC-d
New MAC-e entity located
in the Node B MAC-e entities from
multiple NodeB may serveone UE (soft HO)
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UMTS Networks 10Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
MAC-e/es in UE
MAC-e/es Functions
Priority handling
Per logical channel
Multiplexing
MAC-d flow concept
Mux of data from multipleMAC-d flows into singleMAC-e PDU
Scheduling
Maintain scheduling grant
E-TFC selection HARQ handling
Cf. 25.309
MAC-es/e
MAC Control
Associated Uplink Signalling:E-TFCI, RSN, happy bit
(E-DPCCH)
To MAC-d
HARQ
MultiplexingE-TFC Selection
Associated SchedulingDownlink Signalling
(E-AGCH / E-RGCH(s))
Associated ACK/NACKsignaling
(E-HICH)
UL data(E-DPDCH)
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UMTS Networks 11Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
MAC-e in NodeB
MAC-e Functions
Per user
HARQ handling:ACK/ NACKgeneration
De-multiplexing
E-DCH control:Rx/ Tx controlsignals
E-DCH scheduling for allusers
Assign resources
(scheduling grants)
Iub overload control
Cf. 25.309
MAC-e
MAC Control
E-DCH
AssociatedDownlinkSignalling
AssociatedUplink
Signalling
MAC-d Flows
De-multiplexing
HARQ entity
E-DCH
Control
E-DCHScheduling
Common RG
UE #2
UE #N
UE #1
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UMTS Networks 12Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
MAC-es in SRNC
MAC-es
MAC Control
FromMAC-e inNodeB #1
To MAC-d
Disassembly
Reordering QueueDistribution
Reordering QueueDistribution
Disassembly
Reordering/
Combining
Disassembly
Reordering/
Combining
Reordering/
Combining
FromMAC-e inNodeB #k
MAC-d flow #1 MAC-d flow #n
MAC-es Functions
Queue distribution
Reordering
Per logical channel
In-sequence delivery
Macro-diversity
combining:
frame selection
Disassembly
Cf. 25.309
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UMTS Networks 13Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Data Flow through Layer 2
MAC-es PDUMAC-e header
DATAHeader
DATA
DATA
DDI N Padding(O t)
RLC PDU:
MAC-e PDU:
DDI N DATA
MAC-d PDU:
DDI
RLC
MAC-d
MAC-e/es
PHY
TSN DATA DATAMAC-es PDU:
DATA
DDI: Data Description
Indicator (6bit)
MAC-d PDU size
Log. Channel ID
Mac-d flow ID
N: Number of MAC-d PDUs
(6bit)
TSN: Transmission Sequence
Number (6bit)
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UMTS Networks 14Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Hybrid ARQ Operation
N-channel parallel HARQ with stop-and-wait protocol
Number of HARQ processes N to allow uninterrupted E-DCH transmission 10 msec TTI: 4
2 msec TTI: 8
Synchronous retransmissions
Retransmission of a MAC-e PDU follows its previous HARQ (re)transmissionafter N TTI = 1 RTT
Incremental Redundancy via rate matching
Max. # HARQ retransmissions specified in HARQ profile
New Tx 2 New Tx 3 New Tx 4 Re-Tx 1 New Tx 2 Re-Tx 3 New Tx 4 Re-Tx 1 Re-Tx 2New Tx 1
ACK
ACK
NACK
NACK
NACK
NACK
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UMTS Networks 15Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH UE Scheduling
UE maintains internal serving grant SG
SG are quantized Maximum E-DPDCH/ DPCCH power ratio (TPR), which are
defined by 3GPP Reception of absolute grant: SG = AG
No transmission: SG = Zero_Grant
Reception of relative grants: increment/ decrement index of SG in the SGtable
AG and RG from serving RLS can be activated for specific HARQ processes for
2msec TTI UE selects E-TFC at each TTI
Allocates the E-TFC according to the given restrictions
Serving grant SG
UE transmit power
Provides priority between the different logical channels
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UMTS Networks 16Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Scheduling Grant Table
Index Scheduled
Grant37 (168/15)
2*6
36 (150/15)2*6
35 (168/15)2*4
34 (150/15)2*4
33 (134/15)2*4
32 (119/15)2*4
31 (150/15)2*2
30 (95/15)2*4
29 (168/15)2
14 (30/15)2
13 (27/15)2
12 (24/15)2
11 (21/15)2
10 (19/15)2
9 (17/15)2
8 (15/15)2
7 (13/15)2
6 (12/15)2
5 (11/15)2
4 (9/15)2
3 (8/15)2
2 (7/15)2
1 (6/15)2
0 (5/15)2
Scheduling grants are max.
E-DPDCH/ DPCCH power ratio (TPR traffic to pilot ratio)
Power Ratio is related to UE datarate
Relative Grants
SG moves up/ down when RG = UP/DOWN
Absolute Grants
SG jumps to entry for AG
2 reserved values for ZERO_GRANT/INACTIVE
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UMTS Networks 17Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Timing Relation for Scheduling Grants
AG and RG associated with specific uplink E-DCH TTI, i.e. specific HARQ process
Association based on the timing of the E-AGCH and E-RGCH.Timing is tight enough that this relationship is un-ambiguous.
Example: 10msec TTI
1 2 3 4 1 2 3
E-RGCH
E-AGCH
E-DCH
HARQ process
number
Scheduling
decision
Load
estimation, etc
AG applied to this
HARQ process
RG interpreted relativeto the previous TTI inthis HAR rocess.
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UMTS Networks 18Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Scheduling Information
Happy bit signaling
One bit status flag send on E-DPCCH at each TTI
Criterion for happy bit
Set to unhappy if UE is able to send more data than given withexisting serving grant
Otherwise set to happy
Scheduling Information Reporting
Content of MAC-e report Provides more detailed information (log. channel, buffer status,
UE power headroom)
Will be sent less frequently (e.g. every 100 msec)
Parameters adjusted by RRC (e.g. reporting intervals, channels toreport)
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UMTS Networks 19Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
HSUPA Scheduling
EDCH NodeB Scheduler
QoS ParametersThroughput bounds
Feedback from UE
Scheduling InformationReports
Other constraintsNodeB decoding capabilities
Iub bandwidth limit
UE capabilities
Radio resourcesUL Load (interference)
Allocate (absolute/ relative) SchedulingGrants (max. allowed power offsets)
UE allocates transport formats according tothe allocated grants
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UMTS Networks 20Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
NodeB Load Scheduling Principle
E-DCH scheduler constraint
Keep UL load within the limit
Scheduler controls:
E-DCH load portion of non-serving
users from other cells
E-DCH resources of each serving user
of own cellPrinciples:
Rate vs. time scheduling
Dedicated control for serving users
Common control for non-serving
users
Note: Scheduler cannot exploit fast fading !
Non E-DCH
Non-servingE-DCH users
ServingE-DCH users
UL Load UL Loadtarget
UE #1
UE #m
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UMTS Networks 21Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Rate Scheduling
UEs are continuously active
Data rate is incremental increased/decreased by relative scheduling grants
No synch between UEs required
Load variations can be kept low
For low to medium data rates
Time Scheduling
UEs are switched on/ off by absolutescheduling grants
UEs should be in synch
Load variations might be large
For (verry) high data rates
E-DCH Scheduling Options
time
rate
time
rate
UE1UE2 UE3 UE1
UE1
UE2
UE3
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UMTS Networks 22Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Non-scheduled Mode
Configured by the SRNC
UE is allowed to send E-DCH data at any time
Signaling overhead and scheduling delay are minimized
Support of QoS traffic on E-DCH, e.g. VoIP & SRB
Characteristics
Resource given by SRNC:
Non-scheduled Grant = max. # of bits that can be included in a MAC-e PDU
UTRAN can reserve HARQ processes for non-scheduled transmission
Non-scheduled transmissions defined per MAC-d flow
Multiple non-scheduled MAC-d flows may be configured in parallel
One specific non-scheduled MAC-d flow can only transmit up to the non-
scheduled grant configured for that MAC-d flow
Scheduled grants will be considered on top of non-scheduled
transmissions Scheduled logical channels cannot use non-scheduled grant
Non-scheduled logical channels cannot transmit data using Scheduling Grant
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UMTS Networks 23Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH Operation in Soft Handover
Macro-diversity operation on multiple NodeBs
Softer handover combining in the same NodeB
Soft handover combining in RNC (part of MAC-es)
Independent MAC-e processing in both NodeBs HARQ handling rule: if at least one NodeB tells ACK, then ACK
Scheduling rule: relative grants DOWN from any NodeB haveprecedence
NodeB 1 NodeB 2
UE
scheduling grant
HARQ ACK/ NACK
scheduling grant
HARQ ACK/ NACK
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UMTS Networks 24Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Mobility Handling
The UE uses soft handover for associated DCH as well as for E-DCH
Using existing triggers and procedures for the active set update
(events 1A, 1B, 1C) E-DCH active set is equal or smaller than DCH active set
New event 1J: non-active E-DCH link becomes better than active one
The UE receives AG on E-AGCH from only one cell out of the E-DCHactive set (serving E-DCH cell)
E-DCH and HSDPA serving cell must be the same
Hard Handover, i.e. change of serving E-DCH cell
Using RRC procedures, which maybe triggered by event 1D
Could be also combined with Active Set Update
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UMTS Networks 25Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Mobility Procedures
Inter-Node B serving E-DCH cell change within E-DCH active set
Note: MAC-e still established in both NodeBs !
NodeB NodeB
MAC-e
NodeB NodeB
MAC-e
ServingE-DCHradio link
ServingE-DCH
radio link
s t
SRNC SRNC
MAC-es MAC-es
MAC-e MAC-e
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UMTS Networks 26Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Serving E-DCH Cell Change
SRNC=
DRNC
Target serving
E-DCH cell
UE
RL Reconfiguration Prepare
RL Reconfiguration Ready
Radio Bearer Reconfiguration
Radio Bearer Reconfiguration Complete
Source serving
E-DCH cell
If new NodeB
Synchronous
Reconfiguration
with TactivationRL Reconfiguration Commit
Serving E-DCH cell
change decision
i.e. event 1D
RL Reconfiguration Prepare
RL Reconfiguration Ready
RL Reconfiguration Commit
UE receives now
AG & dedicated RG
from target cell
Handover of E-DCH scheduler control No changes in UL transport bearer No MAC-es RESET
Handover of HS-DSCH serving cell DL transport bearer setup MAC-hs RESET
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UMTS Networks 27Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH RRM Principle
E-DCH resources controlled by
UL load target E-DCH non-serving load portion
NodeB schedules E-DCH usersaccording to RNC settings
Priority for non E-DCH traffic
RNC still controls non E-DCH loadportion
By means of e.g. admission/congestion control
Based on an estimate of non-EDCH loadNon E-DCH
Non-servingE-DCH users
ServingE-DCH users
UL Load UL Loadtarget
Non E-DCHload portion
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UMTS Networks 28Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
0
200
400
600
800
1000
1200
200 400 600 800 1000 1200 1400 1600
Aggregated Cell Throughput [kbps ]
UserThrough
put[kbps]
10ms TTI, unlimited CE dec. rate 2ms TTI, next release
User Throughput vs. Aggregate Cell Throughput
36 cells network
UMTS composite channel
model
FTP traffic model (2 Mbyte
upload, 30 seconds thinking
time)
Maximum cell throughputreached for about 78 UEs
per cell
Cell throughput drops if #UEs
increases further since the
associated signaling channel
consume UL resources too
#UEs/cell1
2
3
4
5
6
7
8
910
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UMTS Networks 29Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Single User Performance
Average user throughput
(RLC layer) for differentchannel profiles
1 UE in the network
1 target HARQ transmission
For AWGN channel
conditions:
10ms TTI: up to 1.7 Mbps
(near theoretical limit of 1.88
Mbps)
2ms TTI: up to 3 Mbps
(below theoretical limit 5.44
Mbps)
E.g. due to restrictions
from RLC layer (window
size, PDU size)
0
500
1000
1500
2000
2500
3000
3500
AWGN P edA3 P edA30 VehA30 VehA120Scena r io
Average
UserThrou
ghput[kbps]
2ms, 1Tx 10ms, 1Tx
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UMTS Networks 30Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
E-DCH Summary
New uplink transmission concept
Optimized for interactive, background and streaming, support of
conversational Full support of mobility with optimizing for low/ medium speed
Improved PHY approach
New UL transport channel: E-DCH
Additional signalling channels to support HARQ and E-DCH scheduling
MAC-e/es entity located in NodeB/ SRNC
Distributed E-DCH scheduling between UE and NodeB E-DCH supports soft/ softer HO
Radio Resource Control procedures similar to HSDPA
E-DCH Resource Management
Cumulated resources managed by Controlling-RNC
Re-use of principles for DCH control (handover, state transition)
Significant improved performance
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UMTS Networks 31Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
References
Papers
A. Ghosh et al: Overview of Enhanced Uplink for 3GPP W-CDMA, Proc.
IEEE VTC 04/ Milan, vol. 4, pp. 22612265 A. Toskala et al: High-speed Uplink Packet Access, Chapter 13 in
Holma/ Toskala: WCDMA for UMTS, Wiley 2010
H. Holma/ A. Toskala (Ed.): HSDPA/ HSUPA for UMTS, Wiley 2006
Standards
TS 25.xxx series: RAN Aspects
TR 25.896: Feasibility Study for Enhanced Uplink for UTRA FDD
TR 25.808: FDD Enhanced Uplink; Physical Layer Aspects
TR 25.309/ 25.319 (Rel.7 onwards): Enhanced Uplink: Overall
Description (Stage 2)
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UMTS Networks 32Andreas Mitschele-Thiel, Jens Mckenheim Nov. 2011
Abbreviations
ACK (positive) Acknowledgement
AG Absolute Grant
AM Acknowledged (RLC) Mode
AMC Adaptive Modulation & Coding
BO Buffer Occupancy
CAC Call Admission Control
CDMA Code Division Multiple Access
DBC Dynamic Bearer Control
DCH Dedicated Channel
DDI Data Description Indicator
DPCCH Dedicated Physical Control Channel
E-AGCH E-DCH Absolute Grant Channel
E-DCH Enhanced (uplink) Dedicated Channel
E-HICH E-DCH HARQ AcknowledgementIndicator Channel
E-RGCH E-DCH Relative Grant Channel
E-TFC E-DCH Transport Format Combination
FDD Frequency Division Duplex
FEC Forward Error Correction
FIFO First In First Out
FP Framing Protocol
GoS Grade of Service
HARQ Hybrid Automatic Repeat Request
IE Information Element
MAC-d dedicated Medium Access Control
MAC-e/es E-DCH Medium Access Control
Mux Multiplexing
NACK Negative Acknowledgement
NBAP NodeB Application Part
OVSF Orthogonal Variable SF (code)
PDU Protocol Data Unit
PHY Physical Layer
PO Power Offset
QoS Quality of Service
QPSK Quadrature Phase Shift Keying
RB Radio Bearer
RG Relative Grant
RL Radio Link
RLC Radio Link Control
RLS Radio Link Set
RRC Radio Resource Control
RRM Radio Resource Management
RV Redundancy Version
SDU Service Data Unit
SF Spreading Factor
SG Serving Grant
SI Scheduling Information
TNL Transport Network Layer
TPR Traffic to Pilot Ratio
TTI Transmission Time Interval
UM Unacknowledged (RLC) Mode