Post on 05-Apr-2018
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OCTOBER 2004
WFI/o2 Workshop
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Isaac OMOTAYO
Project Manager (WFI)
Jeremy RONNEVIGSenior Tools Support Officer (WFI)
Sandy LIENSenior UMTS Optimisation Engr (WFI)
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OBJECTIVE OF WORKSHOP Audience:
Delegates should be RF Engrs/Managers with good knowledge of UMTS Technology.
At the end of the course delegates will be able to: Understand basic UMTS network interfaces/protocols and UTRAN elements.
Understand the factors that can limit/hinder effective optimisation activity.
Understand UMTS optimisation process
Understand why RF Build Audit is essential
Understand Cell Shakedown/Site Verification
Define Cluster Define and Understand difference between Optimisation and Acceptance route
Understand Cluster and inter-cluster optimisation
Understand why good neighbour definition is important
Analyse/Post process data using TEMS
Understand basic layer 3 messages
Identify and Plot Areas of Concern
High Active Set
Low Ec/Io
Low RSCP
Recommend Changes
Analyse and diagnose problem calls
Drop Calls
Failures
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Network Architecture
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UMTS Initial Deployment
BSS
PSTN
A IuCS
GMSC
VLRB
MSC
VLRB
MSC
PSTN PSTN
Gs
G
E
MS
CNGb
Uu
Um
Iur
IuPS IuPSIuCS
RNC
Node BNode B
RNS
lubis
GGSN
SGSN
BSS
BTSBTS
BSC
Abis
Node B
RNC
Node B
RNS
lubis
ME
USIMCu
Um
BTSBTS
BSC
Abis
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UTRAN network elements and interfaces
RNS
RNC
RNS
RNC
Core Network
Node B Node B Node B Node B
Iu Iu
Iur
Iub IubIub Iub
All shown interfaces (Iu, Iub and Iur) are standardisedin order to allow multi vendor networks
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UMTS Glossary
UTRA: UMTS Terrestrial Radio Access Refers to the UMTS radio interface only.
AN: Access Network
The network that consists of all the BSS
RNS: Radio Network System
Equivalent to BSS
RNC: Radio Network Controller
Equivalent to BSC
UTRAN: UMTS Terrestrial Radio Access
Refers to the UMTS BSS
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UMTS Glossary
Core Network
NSS, with both the CS domain (inherited from MSc side), and the IP domain(inherited by the GPRS side)
UE: User Equipment
MS
Iu interface or reference point
Interface between the AN and CN: It has two real interfaces based on similar
principles: the Iucs, for circuit switched, connects top the MSC, and the Iups,for packet switched, connects to the SGSN
Serving RNC
The RNC that has the RRC connection towards the terminal, and also the Iuconnection
Drift RNC
RNC that supports the serving RNC with radio resources when theconnection between the WCDMA RAN and the UE needs to use a cell orcells controlled by this RNC. This is a role that an RNC can take with respectto a specific connection. A drift RNC is connected to a serving RNC throughthe Iur interface.
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UMTS Glossary
Uu
Interface between the UE and Node B
Iub
Interface between a RNC and its Node Bs. Equivalent to Abis Iur
New interface connecting two RNCs
Iu
Interface between RNC and CN.
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UMTS Glossary
Uu
Interface between the UE and Node B
Iub
Interface between a RNC and its Node Bs. Equivalent to Abis Iur
New interface connecting two RNCs
Iu
Interface between RNC and CN.
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UTRAN services to the Core Network
UTRAN is responsible for RRM UTRAN is responsible for the radio connection mobility
UTRAN is responsible for providing Radio AccessBearers on the UTRAN to Core Network Interface, the Iu
interface
UTRAN is also responsible for the following functions: User Equipment (UE) location positioning (used in e.g. LCS)
Security functions
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Channel and Protocol Description
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Radio Interface Protocol Architecture
Radio
Interface
Protocol
Architecture
Transport Channel (SAP)
Physical Channels
Logical Channel
L3
control
control
control
control
Logical
Channels
Transport
Channels
C-plane signalling U-plane information
PHY
L2/MAC
L1
RLC
DCNtGC
L2/RLC
MAC
RLCRLC
RLC
RLC
RLCRLC
RLC
Duplication avoidance
UuS boundary
BMCL2/BMC
RRC
control
PDCPPDCP L2/PDCP
DCNtGC
Packet Data Convergence Protocol:
Is only for PS domain services.
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Radio Interface protocol architecture
L2/MAC
L2/RLC
L1
RLC
MAC
L3RRC
PHY
TransportChannels
LogicalChannels
C-plane signallingU-plane information
GC Nt DC
RLCRLC
RLC
GC
NTDCRRCRLCMAC
General Control
NotificationDedicated ControlRadio Resource ControlRadio Link ControlMedium Access Control
UTRA Protocol Architecture
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Main MAC (Medium Access Control) functions
Mapping between logical channels and transport channels.
Selection of appropriate transport format for each transport channeldepending on instantaneous source rate.
Priority handling between data flows of one UE.Achieved by selecting high bit rateand low bit rateTransport formats for different for
different data flow.
Scheduling of broadcast, paging and notification messages.
Identification of UEs in common transport channels.
Multiplexing/demultiplexing of higher layer PDUs into/from transportblocks delivered to/from the physical layers on common transportchannels.
UTRA Protocol Architecture
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Main RLC (Radio Link Control) functions
Performing establishment, release, and maintenance of a RLCconnection.
Segmentation and reassembly of variable-length higher layer PDUsinto/from smaller RLC PDUs.
Protocol error detection and recovery
In-Sequence delivery of higher layer PDUs (Protocol Data Unit).
Flow control.
Ciphering.
UTRA Protocol Architecture
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UTRA Protocol Architecture
Main RRC (Radio Resource Control) functions
Broadcast of system information.
Establishment, release and maintenance of an RRC connectionbetween the UE and UTRAN.
Establishment, reconfiguration and release of radio access
bearers in the user plane.
Assignment, reconfiguration and release of radio resources for theRRC connection.
Control of requested QoS.
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Channel Definitions
Transport Channel:
the services offered by Layer 1 to higher layersTransport channel defines the method and the characteristicsby which data are transferred over the air-interface
Physical Channel:
Physical channel, usually consisting of radio Frames andtimeslots, is the mechanism with which the data aretransferred over the physical resources such as code,
frequency, phaseand time.
Logical Channel:
MAC layer provides data transfer services on Logicalchannels
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Logical Channel Structure
Synchronisation Control Channel (SCCH)
Broadcast Control Channel (BCCH)
Paging Control Channel (PCCH)
Dedicated Control Channel (DCCH)
Common Control Channel (CCCH)
Control Channel (CCH)
Dedicated Traffic Channel (DTCH)Traffic Channel (TCH)
ODMA Dedicated Control Channel (ODCCH)
ODMA Common Control Channel (OCCCH)
ODMA Dedicated Traffic Channel (ODTCH)
Common Traffic Channel (CTCH)
Shared Channel Control Channel (SHCCH)
(TDD)
(ODMA)
(ODMA)
(TDD)
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Transport Channels
Common Transport ChannelCommon Transport Channels require inband identification ofthe UEs when addressing particular UEs.
Dedicated Transport Channels:
Dedicated Transport Channels require the UEs to beidentified by the physical channel , i.e. code and frequencyfor FDD (code, frequency and timeslot for TDD).
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Transport Channels
Broadcast
Channel (BCH)(Downlink)
Transport Channels
Common ChannelsDedicated Channels
Downlink SharedChannel(DSCH)(Downlink)
Common Packet
Channel (CPCH)(Uplink)
Forward-Access
Channel (FACH)
(Downlink)
Paging
Channel (PCH)(Downlink)
Random-Access
Channel (RACH)
(Uplink)
Dedicated Channel (DCH)
(Down & uplink)
Fast uplink Signaling
Channel (FAUSCH)
(Uplink)
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Transport Channels
Common Transport Channels BCH:The Broadcast Channel (BCH) is a downlink transport channel that is used to
broadcast system- and cell-specific information. The BCH is always transmitted over theentire cell with a low fixed bit rate.
FACH:The Forward Access Channel (FACH) is a downlink transport channel. The
FACH is transmitted over the entire cell or over only a part of the cell using beam-forming antennas. The FACH uses slow power control.
PCH:The Paging Channel (PCH) is a downlink transport channel. The PCH is alwaystransmitted over the entire cell. The transmission of the PCH is associated with thetransmission of a physical layer signal, the Paging Indicator, to support efficient sleep-mode procedures.
RACH:The Random Access Channel (RACH) is an uplink transport channel. TheRACH is always received from the entire cell. The RACH is characterised by a limitedsize data field, a collision risk and by the use of open loop power control.
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Channels
Logical Channels:
Broadcast Control Channel (BCCH), Downlink (DL)Paging Control Channel (PCCH), DLDedicated Control Channel (DCCH), UL/DL
Common Control Channel (CCCH), UL/DLDedicated Traffic Channel (DTCH), UL/DLCommon Traffic Channel (CTCH), Unidirectional (one to many)
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Channels
Transport Channels:
Dedicated Transport Channel (DCH), UL/DL, mapped to DCCH and DTCHBroadcast Channel (BCH), DL, mapped to BCCH
Forward Access Channel (FACH), DL, mapped to BCCH, CCCH, CTCH,DCCH and DTCHPaging Channel (PCH), DL, mapped to PCCHRandom Access Channel (RACH), UL, mapped to CCCH, DCCH and DTCHUplink Common Packet Channel (CPCH), UL, mapped to DCCH and DTCHDownlink Shared Channel (DSCH), DL, mapped to DCCH and DTCH
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Channels
Physical Channels:
Primary Common Control Physical Channel (PCCPCH), mapped to BCHSecondary Common Control Physical Channel (SCCPCH), mapped to FACH, PCHPhysical Random Access Channel (PRACH), mapped to RACHDedicated Physical Data Channel (DPDCH), mapped to DCHDedicated Physical Control Channel (DPCCH), mapped to DCH
Physical Downlink Shared Channel (PDSCH), mapped to DSCHPhysical Common Packet Channel (PCPCH), mapped to CPCHSynchronisation Channel (SCH)Common Pilot Channel (CPICH)Acquisition Indicator Channel (AICH)Paging Indication Channel (PICH)
CPCH Status Indication Channel (CSICH)Collision Detection/Channel Assignment Indication Channel (CD/CA-ICH)
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PROTOCOLS
Network Protocols carried over Iu, Iur and Iub interfaces:
RANAP, RNSAP and NBAP
Radio Interface Protocols - radio protocol stack between the UEand RNC through Node B
RRC, RLC, MAC and PDCP
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NETWORK PROTOCOLS
NBAP (Node B Application Protocol) Is carried over the Iubinterface (b/w RNC and Node B).
Cell Config mgt
System info mgt
Resource Event mgt
Commom Transport channel mgt
Radio Link mgt and supervision
Measurement on common resources
Measurement on dedicated resources
RANAP (Radio Access Network Application Protocol) Is carried overthe Iu interface (b/w RNC and Core Network)
Relocation functions
RAB mgt Transport of non access stratum signalling messages (DTAP).
Paging functions
Security functions (Authentication, Ciphering and Integrity chaeck)
CN info broadcast
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NETWORK PROTOCOLS
RNSAP Radio Network Subsystem Application Protocol) Iscarried by Iur interface
Radio link mgt
Measurement reporting function
Transfer of Uplink and Downlink functions
Power control
Load mgt
Paging functions
Relocation functions.
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Some definitions
Radio Bearer
A service provided on top of the RLC layer Radio Bearers have characteristics which depend essentially on the type of
RLC which is used and the underlying physical channel
Logical channels
A service provided by MAC to RLC
The underlying physical/transport channel may change in time Transport Channels
A service provided to the MAC layer by Layer 1.
is almost equivalent to Logical channels in GSM!
Coded Composite Transport Channels
A multiplex of transport channels in the physical layer
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RRM : Downlink Power Control
Inner loop : TPC command bits sent by UE
SIR est > SIR target => TPC command 0 SIR est < SIR target => TPC command 1
Downlink outer loop function in UE or RNC : sets and updates the SIRtarget, based on quality measurements.
RNC
Node B
UE
TPC
SIR
target Inner loop
Quality Measurements
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RRM : Uplink Power Control
Inner loop : TPC command bits sent by NodeB
SIR est > SIR target => TPC command 0 SIR est < SIR target => TPC command 1
Uplink outer loop function in RNC : sets and updates the SIR target, basedon quality measurements received from the NodeB(s)
RNC
Node B
UE
TPC
SIR
target
Inner loop
uality Measurements
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UTRAN Network Elements
NN Node B
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NN Node B
Functions:Network InterfaceCall ProcessingSignal processingFrequency up/downconversion
Functions:Tx amplificationCoupling
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NODE B
NN has two types of Node B
OTSR (Omni Tx sector Rx) Low Cost and limited capacity
STSR (sector Tx sector Rx)
High capacity
The functions of Node B are:
Air interface Transmission / Reception
Modulation / Demodulation
CDMA Physical Channel coding
Micro Diversity
Error Handing
Closed loop power control
OTSR - Omni Transmit Sector Receive
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OTSR - Omni Transmit Sector Receive
Transmit path :
1 cell, 3 antennas Receive path :continuous
softer handover
1Watt
1Watt1Watt
TRM
DDM
Tx Splitter
PA
DDM DDM
DDM Dual Duplexer module (for Main and Diversity)Tx and Rx out of band filteringIsolation b/w Tx and Rx frequency bandsVSWR alarm monitoring capabilityTMA DC supplying
STSR - Sectorial Transmit Sector Receive
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STSR - Sectorial Transmit Sector Receive
Transmit path :3 cells, 3 antennas
Evolution from OTSR to STSR : no coverage re-engineering
TRM
DDM
PA
DDM DDM
PAPA
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NN RNC
- RANAP - Iu FP
- RNSAP - Iur FP
- NBAP
- Qaal2.CS1
Control Plane User Plane
Network Interface Protocol termination
Radio Resource ManagementRRC termination
RRM strategy
QoS management
UTRAN OA&M
RNC OA&M
Network Interface Protocol termination
- Iub FPs Combining / Splitting
Compression
Ciphering
Radio Protocols
RLCMACATM QoS mgt
Functions:Physical connectivity with
other UMTS nodesRadi protocol terminationUTRAN PS functions
Functions:Control plane ProtocolterminationRRM
iRNC OA&MNode B logical OA&MCall Processing
RNC Applicative Functions
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RNC
RRC
Management of radio resources (establishment, release and termination)
Management of RRC connection of RRC connection between the UE andnetwork (establishment, release)
RRM
The RRM is the most critical resource in wireless systems.
It is in charge of allocating and managing radio resources in the mosteffective way.
QoS
High QoS (ensuring subscribers satisfaction)
High spectrum efficiency (maximum operator revenue)
Easy (re)configuration (lowering operational costs)
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Link Budget Overview
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Link Budget
The object of the link budget design is to calculate maximum cell size under
given criteria:
Type of service (data type and speed)
Type of environment (terrain, building penetration)
Behavior and type of mobile (speed, max power level)
System configuration (Node B antennas, Node B power, cable losses,handover gain)
Required coverage probability
Financial and economical factors (use of more expensive and betterquality equipment or not the cheapest installation method) and to match
all of those to the required system coverage, capacity and quality needswith each area and service.
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Link Budget
Eb/NoProcessingGain
PA Powerdiversity(Tx, Rx)
...
BTSNode B
Eb/NoProcessingGain
PA Powerdiversity(Tx, Rx)
...
MSMS
ServiceService
Cablelossesantennassite configuration(bi, tri-sectorial)
...
SiteSite
marginspropagationmarginspropagation
CellRange TrafficofferedpercellCellRange Trafficofferedpercell
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LB @ X% loadDesign assumptions
ComparisonDecision
Final number of sites
Cell size Cell capacity
# sites for coverage # sites for traffic
adjustload
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All of the design assumptions are correlated
Services
Coverage types
Service areas of coverage
Capacities
Quality of coverageRadio network design results are highly dependant of the design
assumptions :
Any change of one of the assumptions implies to redo the design work !
O2 Link Budget (2000)
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O2 Link Budget (2000)
Maximum path loss for UMTS planning On-Street In-Car In-Build (Dense urban) In-Build (suburban) In-Build (rural) In-train (open line) In-train (cutting)
Units Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze
Soft Handoff Gain dB 4 4 4 3 3 3 4 4 4 4 4 4 3 3 3 3 3 3 3 3 3
Penetration Loss dB 0 0 0 2.3 2.3 2.3 18 18 18 5 5 5 5 5 5 0 0 0 0 0 0
Overall standard dev for measurements dB 5.68 5.68 5.68 7.84 7.84 7.84 5.68 5.68 5.68 8.26 8.26 8.26 8.26 8.26 8.26 10.81 10.81 10.81 11.50 11.50 11.50
Fade Margin dB 9.38 7.27 5.91 12.93 10.03 8.15 9.38 7.27 5.91 13.64 10.58 8.59 13.64 10.58 8.59 17.84 13.84 11.25 18.98 14.72 11.96
Maximum path loss dB 145 148 149 139 142 143 127 130 131 136 139 141 135 138 140 136 140 143 135 139 142
Link Budget Units Uplink Service 64LCD
Environment Vehic. A
Service Rate (Average throughput for packet) 64000
BS antenna height (m) 25
MS antenna height (m) 1.5
Frequency (MHz) 2000Power limit in the DL (if 0, there is no limit) NA
Transmitter
UL/DL load factor (from pole capacity) 60%
% Power of the BS used for common ch NA
% Power used for soft handoff NA
Maximum Total Tx power dBm 21
Maximum Tx power per traffic channel dBm 21
Power used in the Cell (DL) NA
Body Loss / Cable Loss dB 1
Tx antenna gain dBi 0
EIRP dBm 20.00Receiver
Rx antenna gain dBi 16
Body Loss / Cable Loss dB 3
Receiver Noise Figure dB 3.3
Thermal Noise Density dBm/Hz -174
Noise rise due to Interference dB 3.98
No+Ior+Ioc dBm/Hz -166.72
Information Rate dBHz 48.06
Target Eb/(No+Io) dB 3.8
MHA Gain dB 3
Receiver Sensivity dBm -117.86
Cell size On-Street In-Car In-Build (urban) In-Build (suburban) In-Build (rural) In-train (open line) In-train (cutting)Units Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze Gold Silver Bronze
Cell radius Km 2.24 2.59 2.85 2.89 3.54 4.04 0.42 0.48 0.53 1.17 1.45 1.66 1.44 1.79 2.05 2.40 3.18 3.82 2.22 2.99 3.63Cell area Km2 9.76 13.10 15.86 16.25 24.40 31.76 0.34 0.45 0.55 2.67 4.09 5.40 4.06 6.23 8.23 11.28 19.76 28.42 9.62 17.46 25.71
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Coverage vs Interference Control
Li k B d t
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Link Budget
Cell range & cell capacity are limited by the same parameters: Interference in uplink
Power in downlink
Cell breathing phenomenon
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Coverage Vs Interference
WHAT IS THE PILOT POLLUTION ?
Area where the SIR (Signal interference ratio) is too low and below the expectedvalue (Ec/Io >= -12 dB), there is too much interference => the mobile cannotunderstand the pilot channel
HOW TO REDUCE THE PILOT POLLUTION PROBLEM ?
Maximise the signal inside the best server
Minimise the energy overshoot to the neighbor cells with some RF consideration(tilt, azimuth,)
Good Design Bad Design
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a1b1g1a2b2g2
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C i t f
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Coverage vs interference
RF design optimisation for capacity
Multi-Carriers solution
Adding new sites
RF design optimisation for coverage
When the sites are placed, it is necessary to verify that the both UL&DLquality of coverage are reached for each service.
The coverage optimisation is performed on
Site position
Antenna tilt and azimuth
Adding new sites if necessary
Continuous process
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Coverage vs Interference
UMTS network radio design is highly dependant of the designs
assumptions
Optimum network radio design requires accurate design assumptions interms of services, coverage, capacity, and quality of service
UMTS network radio dimensioning is a very complex task, the multi-service capacity and coverage should be treated together, since theyshare the single and the same radio resource.
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BREAK
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Cell Selection and Reselection
Call Setup Process
and
Call Establishment Steps
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Call Establishment Steps
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UE Node B RNC
CCCH / RACH RRC Connection Request
Radio Link Setup Request
Radio Link Setup Response
DL Synchronisation
UL Synchronisation
CCCH / FACH RRC Connection Setup
DCCH RRC Connection Setup Complete
RRC Connection Establishment
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Cell selection and Reselection
Network Selection
Mobile in idle mode acquires the best received UMTS cell and identifies itsscrambling code
Mobile in idle mode selects the PLMN
Cell Selection
Mobile in idle mode selects the cell to camp on according basic criteria
Cell Reselection Mobile in idle mode selects a cell according to parameters broadcasted on the
current cell
Location Registration
The mobile in idle mode informs the network about a change of location area
Handover Mobile in active mode in one cell is handed over to another cell
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Initial Cell Search
The initial Cell Search is carried out in three steps:
Step 1: Slot synchronisation - using the primarysynchronisation channel.
Step 2: Frame synchronisation and code-group identification-using the secondary synchronisation channel.
Step 3: Scrambling-code identification-identified through symbol-
by-symbol correlation over the primary CCPCH with allthe scrambling codes within the code group.
M bil B h i
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Mobile Behaviour
Mobile is switched ON
Does the UE have in memory
the frequency used previously ?
Mobile is searching for P-
SCH on this frequency
YesNo
Mobile is scanning the band from
the lower UMTS Frequency
P-SCH Found No P-SCH
Scanning next
frequency
P-SCH Found
No P-SCH
Cell Selection Cell Selection
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Slot Synchronization
P-SCH1
P-SCH3
P-SCH2
P-SCH1S-SCH1 P-CCPCH P-CCPCH
P-SCH2S-SCH2 P-CCPCH P-CCPCH
P-SCH3S-SCH3 P-CCPCH P-CCPCHP-CCPCH
1 Slot = 667ms
UE synchronizes on the strongest correlation peak
F S h i ti P SCH
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Frame Synchronization
..
2560 chips
acp
Slot # ?
P-SCH acp
Slot #?
16 11S-SCH
acp
Slot #?
2Group 4Slot 12,13,14
slot numberScramblingCode Group #0 #1 #2 #3 #4 #5 #6 #7 #8 #9 #10 #11 #12 #13 #14
Group 0 1 1 2 8 9 10 15 8 10 16 2 7 15 7 16
Group 1 1 1 5 16 7 3 14 16 3 10 5 12 14 12 10
Group 2 1 2 1 15 5 5 12 16 6 11 2 16 11 15 12
Group 3 1 2 3 1 8 6 5 2 5 8 4 4 6 3 7Group 4 1 2 16 6 6 11 15 5 12 1 15 12 16 11 2
Group 61 9 10 13 10 11 15 15 9 16 12 14 13 16 14 11
Group 62 9 11 12 15 12 9 13 13 11 14 10 16 15 14 16
Group 63 9 12 10 15 13 14 9 14 15 11 11 13 12 16 10
256 chips
S-SCH
P-SCH
512 Primary Scrambling Codes divided into 64 groups
S bli C d Id tifi ti
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Scrambling Code Identification
P-SCH
S-SCH
P-CPICH
P-CPICH: Predefined sequence (20 bits) spread with Cch,256,0 scrambled with the primary SC
x OVSFCch,256,0
x SC #i Symbol by SymbolCorrelation ?
Primary DL Scrambling CodeKnown (best correlation peak)
For i = 1 to 8
YesNo
Mapping between group and Scramblingcodes defined in TS 25.331
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Cell Information
P-SCH: Coverage indication, Slot SynchronizationS-SCH: Frame Synchronization, Group identification
P-CPICH: Scrambling Code Identification
P-CCPCH: System Information Broadcast
Logical Channel
BCCH
Transport Channel
BCH
Physical Channel
P-CCPCH
OVSF Cch,256,1Primary Scrambling Code
Transmitted during 9/10th slot
Bit Rate: 12.3 kbps RLC Mode: transparent
Mac-B: transparent
Cell Selection Procedure
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Cell Selection Procedure
Definitions:
Acceptable Cell:
Cell on which UE can obtain limited services (emergency calls)
Suitable Cell:
Cell on which the UE can obtain a normal service
UE States for cell Selection / Reselection:
Camped on any cell:
UE monitors System Information but has chosen a cell irrespective of PLMN
identity Camped on a cell:
UE monitors System Information and paging information
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Cell Selection Parameters
Parameter Object Range Default Value Recommended Value Class
qQualMin CellSelectionInfo Int [-24..0]
(dB)
-10 -16 C2
qRxLevMin CellSelectionInfo Int [-115..-25]
Step = 2 (dBm)
-45 -115 C2
maxAllowedUlTxPower UlUsPowerConf Int [-50..33]
(dBm)
33 33 C3
P_Max = maximum UE output power (dBm) according to its class
Power Class Maximum Output Power (dBm)
1 33
2 27
3 24
4 21
C ll R l ti P d
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Cell Reselection Procedure
?2G
3GFreq. 2
3GFreq. 1
General Description:
On a cell, the UE listens to system information andperforms radio measurements
The network controls what the UE shall measure andsends the system information data concerning theneighboring cell
The UE then uses an algorithm to select a better cell The Inter-Frequency algorithm uses a set of broadcast
parameters :
a criteria for searching Inter-frequency cells andperforming measurements
a criteria S to assess whether the cells are eligible
a criteria R for ranking eligible cells and determining
the best one
3G can be favoured compared to 2G by playing on engineering parameters
Cell Reselection Proced re
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Cell Reselection Procedure
Squal
SintraSearch
SinterSearch
SinterRATMeasurement on
same frequency Measurement on
other frequencies Measurement on
other RAT
If Squal = CPICH_Ec/No qQualMin < ThresholdAssociated measurements are performed
Thresholds are broadcasted in SIB 11
In UMTS02, 2 types of measurements are done: Intra frequency and inter RAT
Threseholdsgivenasexample
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Cell Reselection Parameters
Parameter Object Range Default Value Recommended Value Class
qHyst1 CellSelectionInfo Int [0..40] (dBm)Step = 2
10 4 C2
qHyst2 CellSelectionInfo Int [0..40] (dB)Step = 2
4 6 C2
qOffset1sn GSMCell Int [-50..50] (dB) 0 TBD C0
qOffset2sn UMTSFDDNeighbouring Int [-50..50] (dB) 0 TBD C0qualMeas CPICH_EcNo or
CPICH_RSCPCPICH_EcNo N.A. Static
tReselection CellSelectionInfo Int [0..31] (s) 31 6 C2
M bilit i Idl M d St t
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Mobility in Idle Mode Strategy
Target:Staying in UMTS as much as possibleUMTS cells
GSM cells
Squal
No Intra frequency measurements
Intra frequency measurements performedNo Inter frequency measurements
Inter frequency measurements performed
No Inter System measurements
Inter system measurements performed
Sintrasearch
Sintersearch
SsearchRAT
Measurement Trigger:
Sintrasearch > SsearchRAT
For the serving cell Rs = Qmeas,s + qHyst
For the neighboring cells
Rn = Qmeas,n - qOffset
Cell Ranking CriteriaQoffset (3G cell) < Qoffset (2G cells)
Qhyst set to a high value
qRxLevMin setting not too low to avoid too many 2G eligible cells
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Cell Access Restrictions
Parameter Object Range Default Value Recommended Value Class
accessClassBared FDDCell List 0..15Barred/notbarred
N.A. N.A. C0
barredOrNot FDDCell BarrednotBarred
notBarred notBarred C0
cellReservedForOperatorUse FDDCell ReservednotReserved
notReserved notReserved C0
cellRservationExtension FDDCell ReservednotReserved
notReserved notReserved C0
intraFreqCellReselectInd FDDCell AllowednotAllowed
Allowed Allowed C0
tBarred FDDCell barredS10, barredS20, barredS40,barredS80, barredS160, barredS320,barredS640, barredS1280
BarredS160 TBD C0
The following parameters allow to restrict access to some cells. They prevent to send the
initial access message, but there is no impact on cell selection/reselection
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Measurements
Measurements
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The different types of air interface measurements are:
Intra-frequency measurements: measurements on downlink physical channels at thesame frequency as the active set. A measurement object corresponds to one cell.
Inter-frequency measurements: measurements on downlink physical channels atfrequencies that differ from the frequency of the active set. A measurement object
corresponds to one cell.
Inter-RAT measurements: measurements on downlink physical channels belonging toanother radio access technology than UTRAN, e.g. GSM. A measurement objectcorresponds to one cell.
Measurements
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Measurements
Traffic volume measurements: measurements on uplink traffic volume. Ameasurement object corresponds to one cell.
Quality measurements: Measurements of downlink quality parameters, e.g.downlink transport block error rate. A measurement object corresponds to onetransport channel in case of BLER. A measurement object corresponds to onetimeslot in case of SIR (TDD only).
UE-internal measurements: Measurements of UE transmission power and UEreceived signal level.
UE positioning measurements: Measurements of UE position.
The UE supports a number of measurements running in parallel. The UE alsosupports that each measurement is controlled and reported independently ofevery other measurement.
Handover (Handoff)
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Handover (Handoff)
There are following categories of handover (also referred to as handoff):
Hard handover means that all the old radio links in the UE are removed beforethe new radio links are established. Hard handover can be seamless or non-seamless. Seamless hard handover means that the handover is not perceptible tothe user. In practice a handover that requires a change of the carrier frequency(inter-frequency handover) is always performed as hard handover.
Soft handover means that the radio links are added and removed in a way thatthe UE always keeps at least one radio link to the UTRAN. Soft handover isperformed by means of macro diversity, which refers to the condition that severalradio links are active at the same time.
Softer handover is a special case of soft handover where the radio links that areadded and removed belong to the same Node B (i.e. the site of co-located basestations from which several sector-cells are served.
Handover (Handoff)
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Handover (Handoff)
The most obvious cause for performing a handover is that due to itsmovement a user can be served in another cell more efficiently (like less
power emission, less interference). It may however also be performed forother reasons such as system load control.
Active Set is defined as the set of Node-Bs the UE is simultaneouslyconnected to (i.e., the UTRA cells currently assigning a downlink DPCH to
the UE constitute the active set).
Cells, which are not included in the active set, but are included in theCELL_INFO_LIST belong to the Monitored Set.
Cells detected by the UE, which are neither in the CELL_INFO_LIST nor inthe active set belong to the Detected Set. Reporting of measurements of thedetected set is only applicable to intra-frequency measurements made byUEs in CELL_DCH state.
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SOFT HO
It applies to dedicated physical channeland is only applicable when a DTCH isallocated. It is a case when more than onebase station (Node B) has acommunication link established with theUE. The UE is connected to a set of cellsknown as the active set.
The maximum active set size at the RNC is determined by theparameter MaxAciveSetSize
Intra Node B
Inter Node B
Intra RNC Inter RNC
Soft HO diagram
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SOFTER HO
It is a case where the cellscommunicating with the UE are part ofthe same base station (Node B).
Softer HO diagram
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SOFT HO (Intra RNC)
Intra RNC soft HO
The cells involved in the processbelong to different Node Bs that areconnected to the same Serving RNC(SRNC).
Soft HO (Intra RNC)
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Soft HO (Inter RNC)
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This is when the Drift and Serving RNCcomes into play.
The Serving RNC is in charge of theRNC connection to the mobile (UE)
The drift RNC controls the Node B thatdoes not belong to the Serving RNC
and for which a radio link needs to beestablished with the mobile.
An Iur, link between the SRNC andDRNC is required to perform the interRNC soft HO. If this link is not present,
a HO will take place.
From the SRNC to the UTRANtransport perspective the, the DRNCacts as a router.
Inter RNC soft HO
SOFT HO (Inter RNC)
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SOFT/SOFTER HO ALGORITHM
The purpose of the Soft HO algorithm (also referred toas active set update algorithm) is to ensure that thestrongest cells in the UE environment will be part of itsactive set i.e supporting the call and carrying the user
information.
PRIMARY CELL ELECTION ALGORITHM
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(MONITORED SET UPDATE)
The primary cell election algorithmapplies to soft HO. It is used for
monitored set determination and a pointerto mobility parameter.
The Monitored Set should be updatedeach time the primary cell of active setchanges. A measurement controlmessage is sent (with measurement
commend set to modify) is sent to the UEin order to update the monitored set. Themessage contains the cell to add/removefrom the monitored and should follow theACIVE SET UPDATE message.
The primary cell algorithm is called from
SHO algorithm; therefore it is performedeach time a MEASUREMENT REPORT isreceived by the SRNC.
Measurement control used for monitored set update
CS - UE Originating - Call setup
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CS UE Terminating - Call setup
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CS UE Originating - Call release
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CS Network Originating - Call release
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PS UE Originating PDP Context Activation
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PS UE Originating PDP Context DeActivation
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g g
Inter-System Handover
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The RANAP signalling used on the UMTS side is the relocation signalling. It is used forCS scenarios but also for PS scenarios where the relocation can be initiated by thenetwork. The signalling on the GSM side is the BSSMAP handover signalling. Thesignalling on the GPRS side is the GMM routing area update signalling.
Conversions The 3G MSC needs to convert RANAP to BSSMAP so that it can support
handovers from UMTS to GSM. For GSM to UMTS handovers it also has toconvert BSSMAP messages to RANAP messages.
The UE-CN signalling is very similar in 2G or 3G. No conversion is needed to
accommodate the differencies.
Inter System Handover
Handovers for CS-domain: key interfaces
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UE
GSMBSS
RANAP,
BSSMAPSignallingMEGACO
UTRAN
PSTNG/W
WirelessGateway
Iu
ISUP 2G-MSC
UE
UMTS CallServer
3G to 2G handover (CS domain)
UE
GSMBSS
2G-MSC
UE
UTRAN
PSTNG/W
WirelessGateway
Iu
ISU
P
ISUPMEGACO
UMTS CallServer
RANAP,BSSMAPSignallingMEGACO
2G to 3G handover (CS domain)
ISUPMEGACO
Call is
anchoredat WirelessGateway
Present inUMTS 2d
release only
3G to 2G Handover (UE connected to CS domain moves to GSM)UE UTRA G MSC BSS
UMTSWireless PSTN
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RN: Relocation command
RN: Iu release command
RN: Relocation Required
Classmark 2, Classmark 3
Source RNC to target
RNC transparent container
BM: Handover request (CM2,CM3, old BSS to new BSS)
PS Domain Routing Area Update if required
UE UTRAN
Key to protocol name abbreviations:
RRC - Radio Resource ControlRN - RANAPBM - BSSMAP
2G-MSC BSS
MAP: Prepare HandoverRequest (CM2, CM3, oldBSS to new BSS info)
MAP: Prepare HandoverResponse
BM: Handover request Ack
RN: Iu release complete
RRC: Handover command
BM: Handover detect
BM: Handover complete
RRC: Handover Complete
MAP: Send End SignalRequest
UMTSCall Server
The UMTS Call Server convertsRANAP to BSSMAP and sendsBSSAP messages to the 2G-MSC,with BSSMAP messagesencapsulated.
This conversion includes conversionfrom transparent container used inUMTS to the old BSS to new BSS IE
in BSSMAP.
The UMTS Call Server uses 2Gciphering keys for relocation to 2Gand sends the ciphering informationvia MAP.
e essGateway/SGSN
SGateway
Q2630.1 REL
Q2630.1 RLC
ISUP: IAM
ISUP: ACM
ISUP: ANM
Hard handover from UMTSto GSM
Anchor retained in UMTSnetwork - UMTS call
control and servicesthroughout call
Backwards compatible withGSM network elements
Also possible when GSMcells are connected to theUMTS core network
Gateway andBackbone controlsignalling
Q.AAL2signalling
BSSMAPmessage
encapsulated
Contains GSMinformation forBSS (08.08)
Only includedwhen target is
GSM
RANAP to BSSMAPConversion
This is MEGACOsignalling in UMTSrelease 2 with the
PSTN GatewayThis is BSSMAPsignalling in UMTSrelease 1; no PSTNGateway
2G to 3G Handover (UE connected to GSM moves to UMTS)G SC
WirelessUMTSUTRAN
PSTN
Contains allthe
BSSMAP
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BM: Handovercommand
BM: Clearcommand
BM: HandoverRequired
Old BSS to newBSS info
Source RNC totarget RNCcontainer
RN: Relocation request (Source RNC to target RNC transparent container)
PS Domain Routing Area Update
UE BSS 2G-MSC Gateway/SGSN
Call ServerUTRAN
MAP: Prepare HandoverRequest (BSS-APDU)
MAP: Prepare HandoverResponse
RN: Relocation request Ack
BM: Clear complete
RRC:Handovercommand
RN: Relocation detect
RN: Relocation complete
RRC: Handover Complete
MAP: Send End Signal
Request
The UMTS Call Serverconverts BSSMAP messagesencapsulated in BSSAP to
equivalent RANAP messagesfor the Iu interface.
The ciphering keys receivedfrom the 2G-MSC areconverted into 3G cipheringkeys by the UMTS call server.The keys are then applied tothe UTRAN.
Q.2630.1 ERQ
Q.2630.1 ECF
Gateway
ISUP: IAM
ISUP:ACM
ISUP:ANM
Anchor retained in GSMnetwork - GSM call controland services throughoutcall
Backwards compatible withGSM network elements
Also possible when GSMcells are connected to theUMTS core network
Q.AAL2signalling
GatewayandBackbone
controlsignalling
Contains UEcapability info
messageBSSMAP to
RANAPconversion
ISUP:ACM
Additions toBSSMAPmessages forhandover toUTRAN isunder way
Handovers for PS-domain: key interfaces
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UE
GSMBSS
UTRAN
3G-SGSN
GGSN
Iu 2G-SGSN
UE
3G to 2G handover (PS domain)
UE
GSMBSS
2G-SGSN
UE
UTRAN
GGSN
3G-SGSN
Iu
GTP
2G to 3G handover (PS domain)
GTP
Gn
Gn
GTP GT
P
3G to 2G Handover (UE connected to PS domain moves to GPRS)UE UTRAN 2G-SGSN BSS3G-SGSN GGS
HLR
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U
The trigger for the handover can bethe UE. Or, the serving RNC cantrigger the handover to GPRS basedon UE measurements. In any case theUE stops sending UL to 2G
Key to protocol name abbreviations:
GMM - GPRS Mobility ManagementGTP - GPRS Tunnelling protocolRN - RANAP
GTP: SGSN Context Request
GTP: SGSN Context Response(MS network capabilities)
RN: Iu release complete
RN: SRNS Context Request
RN: SRNS Context Response
GTP: SGSN Context Ack
N-PDU Data Transfer
N-PDU Data Transfer
GMM: Routing Area Update Request (MS radio access capabilities)
N
GTP: Update PDP Context Request
GTP: Update PDP Context Response
GMM: Routing Area Update Accept
GMM: Routing Area Update Complete
handover from UMTS toGPRS
Backwards compatible withGPRS network elements
Also possible when GSMcells are connected to theUMTS core network
The 3G-SGSN does theQoS mapping. By movingto 2G, the UMTS QoSservices are lost
Data forwarding
The source RNC instructs the CN aboutDL/UL GTP/PDCP PDU sequence
numbers for lossless relocation
Contains MSGPRS/UMTS
cipheringcapabilities
RN: SRNS data forward command
3G-SGSNstarts a timer
Timer expiry
MAP: Update GPRS location
RN: Iu release command
MAP: Cancel location
MAP: Cancel location ack
MAP: Insert subscriber data
MAP: Insert subscriber data ack
RRC: Handover command
UTRAN addsCGI (RAC, LAC)
TLLI and P-TMSI usage in GMM/GTP messages to be checked
UTRAN stopssending DL to
UE
Security functions
The 3G-SGSN converts the 3Gciphering keys into 2G keys (see33.102). These keys are sent in the
GTP:SGSN context responsemessage.
When doesthe packetforwarding
stop?
Compressed Mode
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Compressed Mode
During inter-frequency handover the UEs must be given time to make the
necessary measurements on the different WCDMA carrier frequency. 1 to 7slots per frame can be allocated for the UE to perform this intra frequency(hard handover).
Why is compressed mode needed?
In UTRAN FDD, transmission/reception by the mobile is continuous : no idle periods areavailable for monitoring other frequencies if the UE has only a single receiver
How is it done?
Transmission gaps are created in the radio frame in DL and/or UL to allow the UE toswitch to another frequency, perform measurements on another carrier (FDD, TDD orGSM) and switch back
Transmission gaps are positioned in one radio frame or at the boundary of 2 radio framesin regular intervals referred to as a transmission gap pattern sequence no more than 7 slots are used in any one radio frame to create the transmission gap.
Compressed Mode
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How is it done?
Two approaches can be taken in creating the transmission gaps of the
transmission gap pattern sequence Modifiy the physical layer parameters (by puncturing or spreading factor reduction) to allow all
information bits to be transmitted.
Restrict the bit rate (by higher layer scheduling) to match the fewer available transmission slots in acompressed radio frame.
In both approaches, the goal is to not loose transmission frames
Compressed Mode
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Compressed Mode
Who controls it?
Compressed mode is under the control of the UTRAN
Compressed mode is configured by the RNC per UE in the form oftransmission gap pattern sequences given to the UE via RRC signalling
given to the node B via NBAP signalling
a transmission gap pattern sequence is associated with a specific measurement purpose: FDD measurements,
TDD measurements,
GSM initial BSIC identification, GSM BSIC reconfirmation,GSM RSSI measurement
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OPTIMISATION
Optimisation - Optimisation Process
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Server
Route definition
Data Collection
Data AnalysisSignal PropagationAnalysis
FTP
Drive Team A Drive Team B
Drive Team C
FTP
Aspirational Goals for Optimisation
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Aspirational Goals for Optimisation
Three type of RF Optimisation Targets
CPICH_RSCP: Optimisation will aim to provide Dense Urban or Suburban CPICH signal
levels according to the criterion presented in next slide.
CPICH_Ec/Io:
Optimisation will aim to provide a CPICH_Ec/Io >= -11 dB in 100% of the bins
where the CPICH_RSCP target is met.
Optimisation will aim to provide a CPICH_Ec/Io >= -9 dB in 95% of the binswhere the CPICH_RSCP target is met.
For the areas where the target CPICH_RSCP can not be met, optimisationwill aim to maximise the number of bins where CPICH_Ec/Io >= -9 dB.
Number of Cells within a 7 dB window from the best server: Optimisation will aim to obtain at maximum 4 cells (including best server)
within the window for 95% of the bins where the CPICH_RSCP target is met.
Optimisation will aim to maximise the number of bins where the number ofcells within the window is at maximum 4 (including best server) for areaswhere the CPICH_RSCP target is not met.
RF Build Audit
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Why do you need to carry out RF Build Audit ? To ensure accurate and correct planning tool database
To verify site installation/build is consistent with design
To ensure that as-built drawing is correct and up-to-date
To limit unnecessary time wasting during optimisation
To ensure that optimisation changes recommendation are effective.
Cluster Definition
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Cluster Size
Cluster is a group of sites.
It could be defined subject to availability of sites (small cluster e.g 5 sites)
It could be defined subject to time constraints (large cluster) Cluster size should be limited to 20-30 sites to allow faster optimisation.
Cluster drive test survey should not exceed 1.5 to 2 days.
Cluster Definition rules
A site can only belong to one cluster The cluster boundary should be a polygon that minimises the boundaries with neighbouring
clusters.
If possible, cluster borders shall be defined along natural barriers for the RF propagation
The urban centres shall be kept as close as possible the centre of a cluster.
Key roads and rail routes should be avoided as cluster boundaries.
Identified boomer sites, high sites or sites with poor RF quality shall, whenever possible, belocated close to the centre of the cluster.
Open areas such as stretches of water or sides of valleys where propagation would beenhanced cannot be considered in isolation and a cluster shall include the whole open area.
Optimisation Route Definition
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Optimisation Route definition rules
Drive test to be done in 1 day (small cluster) and 2 days max. (large cluster).
All sectors in every site in the cluster should be covered by the drive route.
Drive routes shall be defined to cross the edges of 3G coverage (i.e. when the mobile hands
over to 2G), to ensure that the 3G edge of coverage is crossed whilst drive testing.
Routes should be defined around key business centres, shopping centres, tourist attractions
and railway stations.
Route must include major roads: Motorways, A roads, B roads and other important road.
The routes should be laid out to gain a clear footprint of each cell (that can be achieved within
1 day), such that close-in problems such as low transmit power as well as far-off problems
such as spill-over can be observed.
Acceptance Route Definition
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Acceptance Route Definition Rules
The Drive Test Routes for Cluster Acceptance shall be a sub-set of the optimisation route.
Drive test to be done in 1 day (small cluster) and 2 days max. (large cluster).
All sectors in every site in the cluster should be covered by the drive route.
Drive routes shall be defined to cross the edges of 3G coverage (i.e. when the mobile hands
over to 2G), to ensure that the 3G edge of coverage is crossed whilst drive testing.
Routes should be defined around key business centres, shopping centres, tourist attractions and
railway stations.
Route must include major roads: Motorways, A roads, B roads and other important road.
The routes should be laid out to gain a clear footprint of each cell (that can be achieved within 1
or 2 days), such that close-in problems such as low transmit power as well as far-off problems
such as spill-over can be observed.
Inter Cluster Optimisation Definition
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Objective:
The objective of network optimisation is tooptimise all clusters covering an entire
region.
Process:
refer to Cluster Optimisation guidelines.
Focused on the areas affected by cells with
cross-cluster effects Optimisation Drive Test Routes will cover all
cells belonging to cluster B and buffer areasin clusters A and C.
The optimisation of 1st and 2nd tier sectorsof clusters A and C pointing to cluster B will
be done at this stage.
Cell Shakedown/Site verification
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Objective
The objective of the cell shakedown is to ensure that sites are operating properly.
Cell Shakedown is the last check after integration and prior to optimisation to detect any residual
issues affecting effective site operation.
Sector
g
CarrierCode gPower
g
Sector
a
CarrierCode aPower
a
Sector
bCarrierCode bPower
b
(Pre-requisites)Antenna sweep tests must be
successfully completed
Integration tests must be passedand accepted
RNS, NSS and WG datafillparameters must be verified indetails.
Cleared spectrum
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Cell Shakedown
Purpose To test Call Setup (Voice and FTP) in each cell
To test Handoffs (Soft and Softer) between Cells
Verify antenna orientation
Primary Pilot Ec/Io
Scrambling Code for each cell
UE transmit power
Path Balance
Method
By driving clockwise and anticlockwise within a designated route around thethe base station (about 30% of the site coverage area).
Optimisation - Atoll Neighbour List generation
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Atoll Mapper
Neighbour List Generated
Effective neighbor listplanning, save unnecessary
drive test
Neighbour List Generationis base on :-
Atoll coverageprediction to generate abaseline neighbor list
automaticallyMapper neighborverification wereconducted base on localknowledge and terrainprofile analysis
NOTE: This is an example as o2 is using Odyssey planning tool.
Neighbouring Plan Optimisation (2G Neighbours)
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Neighbouring Plan Optimisation (2G Neighbours)
Thresholds for analysis of outdoor measurements
1. Outdoor areas where the 3G coverage is insufficient
CPICH_RSCP
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The 3G to 2G HHO is considered to be necessary in 3 RF Scenarios:
1. Outdoor areas where the 3G coverage is insufficient
These regions will be identified using the 3G RSCP outdoor measurements considering the
cpichRscpThresholdused to trigger the compress mode and the hard handover to 2G. Within theseregions the 2G measurements done in active mode will be analyzed. The top 2G cell will be
considered as a neighbour as long it provides enough signal strength and dominance.
2. Areas where the Ec/Io is lower than the target for 3G/2G handover
These regions will be identified using the 3G EcIo measurements considering the
cpichEcNoThresholdused to trigger the compress mode and the hard handover to 2G. Within these
regions the 2G measurements done in active mode will be analyzed. The top 2G cell will be
considered as a neighbour as long it provides enough signal strength and dominance.
3. Indoor
These regions will be identified using the 3G RSCP outdoor measurements considering the
cpichRscpThresholdused to trigger the compress mode and the hard handover to 2G corrected with
the deep indoor penetration margin. Within these regions the 2G measurements done in active mode
will be analyzed. The top 2G cells will be considered as a neighbour as long they provide enough
signal strength and dominance
Note: Due to current software limitations only 16 2G neighbours can be define per 3G cell. Whenever this number
proves to be insufficient, the cluster exit reports will include a list of the necessary but undefined 2G neighbours
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Optimisation
Scanner data vs UE data analysis
Antenna Configuration Change
Identifying area of concern due to poorEc/Io, Active set, RSCP
Recommending optimisation changes
Neighbour list definition
Analysing Problem Calls (Voice, Data andVideo).
Diff b t S d t & UE
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Difference between Scanner data & UEData Collection
Scanner
Primary Common Pilot Channel (P-CPICH)scrambling code measurements
Continuous Wave (CW) measurements
Spectrum analysis
Synchronization Channel (SCH) code wordmeasurements
UE Data/Voice/Video Calls
Layer 3 messages logging
Layer 2 messages logging (Transportchannel)
RRC State logging
UE Transmit Power
SIR
Serving Cell / Active Set / Monitored Set
Events
GSM neighbor measurements
Difference in data collectionAntenna
Cable
Sampling
Solution: Perform a calibration drive.
S d UE D t P t P i
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Scanner and UE Data Post-Processing-Export Logfile Export Logfile
Log file => export logfile
S d UE D t P t P i R t
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Scanner and UE Data Post-Processing-ReportGenerator
Report Generator
Log file => Report Generator
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Antenna Configuration Change
A t C fi ti Ch
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Antenna Configuration Change
A cell broadcasts channels with
different frequencies and orslots.1. The neighbouring cellsutilise
different group of frequencies,which helps mitigate inter-cellinterference. This is achieved by
the frequency planning process.
Both of the options are not
available in WCDMA.
Solution:Techniques such as down-tilt and
azimuth changes, which direct RFenergy from undesired areas to
desired areas, are likely to becrucial in controlling pilot pollutionand maximising capacity.
GSM WCDMA
Whyuse it widely for WCDMA?
Antenna Configuration Change (example)
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Antenna Configuration Change (example)
View from Site 869 along approximate sector 2 azimuth
Antenna Configuration Change
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Antenna Configuration Change(example), Cont.
RSCP plot for sector 2 of site 869 (SC 104) with 6EDT
neighbor relations
Antenna Configuration Change
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Antenna Configuration Change(example), Cont.
RSCP plot for cell sector 2 of site 869 (SC 104) with 6EDTand 4MDT
TEMS Scanner WCDMA and UE (applications)
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TEMS Scanner WCDMA and UE (applications)
Neighbor list optimization Best servers according to Serving Cell / Active Set / Monitored Set
Increase scanning capability, e.g. scan on different frequencies
Missing neighbor detection (application)
Optimization of neighbor relations Turn interferer into useful link, (Include interfering cell in neighbor list Interferer will turn into a wanted signal in SHO)
Distance between cells suitable for neighbours should be considered
Increased numbers of soft handovers can cause capacity problems
TEMS Scanner WCDMA and UE (applications)
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TEMS Scanner WCDMA and UE (applications)
An overview of cluster performancebased on scanner Best ServingCPICH RSCP and Ec/Io measureddata.
An overview of cluster performancebased on UEs perceived Best Serving
CPICH RSCP and Ec/Io measured data.
Data are used to assist detailedvoice/video/data call analysis.
Events
Handover
Blocked call
Drop call
Poor Coverage
Missing Neighbours Pilot Pollution (overshooting or poor
coverage)
Scanner UE
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Optimisation Example 1 Scannerv.s. UE data
Scanner Best Serving CPICH RSCP Plot
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Scanner Best Serving CPICH RSCP Plot
Measured Scanner Best Server CPICH RSCP Plot.
UE Best Serving CPICH RSCP Plot
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UE Best Serving CPICH RSCP Plot
Measured UE Active Set Best Server CPICH RSCP Plot
Scanner Best Serving CPICH Ec/Io Plot
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Scanner Best Serving CPICH Ec/Io Plot
Measured Scanner Best Server CPICH Ec/Io Plot
UE Best Serving CPICH Ec/Io Plot
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UE Best Serving CPICH Ec/Io Plot
Measured UE Active Set Best Server CPICH Ec/Io Plot
Note: The Ec/Io of UE isworse than Scanner due
to missing neighbours(some are caused byovershooting cells)
UE Best Serving CPICH Ec/Io Plot
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UE Best Serving CPICH Ec/Io Plot
Measured UE Active Set Best Server CPICH Ec/Io Plot
Identify problem areas
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Optimisation Example 1 Cont.Poor Ec/Io
Identifying area of concern Poor Ec/Io e.g due to
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Identifying area of concern Poor Ec/Io e.g due toOvershooting
Both SC27 & SC43from site 53 areovershooting the area
Identifying area of concern Poor Ec/Io Poor e.g.
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Identifying area of concern Poor Ec/Io Poor e.g.due to Overshooting-Cont.(TEMS Map)
Geographical Location for drop call near site 32472
Poor Ec/Io Poor Ec/Io due to Overshooting-Cont.
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Poor Ec/Io Poor Ec/Io due to Overshooting Cont.
Individual SC RSCP Plot for SC27 Individual SC RSCP Plot for SC43
Site 53 has 2 cells, 30 meters high and with no tilt.
Overshooting, Cont. (another area)
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Overshooting, Cont. (another area)
Geographical Location for drop call near site 3855
Caused by Overshooting site 53 (SC27)
Overshooting, cont.(SC27 P-CPICH RSCP plot)
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Overshooting, cont.(SC27 P CPICH RSCP plot)
Individual SC RSCP Plot for overshooting cell(SC27)
Recommending Optimisation changes
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Recommending Optimisation changes
Apply 4 degrees down tilt to Both Sector 1& 3 of site 53
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Optimisation Example 1 cont.Active Set
Optimisation Example Cont..-Pilot Pollution
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(Active Set related)
Lack of Dominant Cell
but margin o.k. Ec/Iofor SC171, SC155,SC99 in AS.
SC43 has strong RSCP & Ec/Ioand is overshooting the area.
Recommending Optimisation changes
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g p g
Once again, apply 4 degrees down tilt to SC43 (sector 3 of site 53)
Then re-drive the area and check dominate serving P-CPICH and Ec/Io of the area.
Tips: The report generator can also show an event call more than 3 strong SCswhich indicates there can be pilot pollution issue.
Optimisation Example 1 cont.
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p pPoor Coverage
Poor RSCP and Ec/Io forServing Cell (SC150) andMonitoring Cells (SC53 &SC94).
Recommending Optimisation changes
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g p gfor Example on Poor Coverage
Location of Poor Coverage Area nearplanned sites 31061 & 34800
Solution:
Need planned sites 34800to be on air
planned sites
Neighbour Planning
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g g
3G->3G Use planning tool (e.g. Atoll) to assist on initial neighbour planning.
Select cells with overlapping coverage to serving cell (e.g. other cells inthe serving cell site & the first tier cells around the serving cell).
Special cases: motorway (high speed drive).
Add neighbour relations mutually.
Priorities neighbour list.
Avoid long list of neighbours.
Avoid 2nd order SC clashes.
Drive test and perform drop call analysis after initial neighbour lists are on
the network. Add missing neighbours and re-drive test the area.
Neighbour Planning -Avoid long list of
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g g gneighbours
When Soft/Softer Handover is executed, a new Active Set is created.
According to the new Active Set, the new list of neighbours (modification)is sent to the UE in a new MEASUREMENT CONTROL message.
If the new list of neighbour is greater than max allowable numbers of
neighbours for one cell (e.g. 32 neighbours), the excessive numbers ofneighbours will be truncated.
To avoid this, prioritise the neighbour list.
Also, keep neighbour list short. (e.g. 16 neighbours per cell).
Neighbour Planning-Motorway example
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g g
Car speed drivewould pass severalcells quickly, thusmay need more moreneighbours along the
motorway.
Neighbour Planning-Avoid 2nd order SC
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clashes
Cell B and D have the same SC
UE in soft handover between Cell Aand C
If the UE is in softhandover between cells Aand C, and cells B and Dhave the same PSC thenthe UE will be sent thisPSC twice.
This will prevent the UEfrom being able toaccurately report on thesePSCs and make handoverdecisions.
Solution: Avoid use sameSC in nearby cells.
Neighbour Planning
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3G->2G
Since the 2G network is more mature than the 3G network, most likely, a3G site would have a 2G equivalent site.
If so, use same 2G neighbour list for 3G (including the 2G equivalent cell).
If not, apply same principle for 3G neighbour planning to 2G. Each 3G cell and specify that a mutual 3G relation is to be added on the
2G cell.
Neighbour Planning (TEMS Map), Cont.
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Click on theserving cell to
show its defined3G neighbours.
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Lunch!
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Analysing problem calls
Common Problem Summary
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Description Category
Overshooting Parameter
No coverage RF
Missing neighbouring relationship Parameter
Call dropped after active set update UE
PDP Context Activation Failure Core Network problem
Missing neighboring relationship
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Symptom:
Before connection drop, the CPICH_Ec/No of the serving cell gets worse and
detected neighbour has better Ec/No. After connection drop, when a new call is
established, the UE will connect to another cell with better CPICH_Ec/No, which is
not in the previous monitored set.
Possible solution:
Add the missing neighbour relationship to the neighbouring list.
Remove that cell coverage if it is an overshooting cell.
Missing neighboring relationship, cont.
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Before dropped call:Detected Neighbour has good
RSCP level.
Missing neighboring relationship, cont.
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UE keeps sendingMeasuerment Reportsreporting (event 1a forSC83) but no responsefrom UTRAN.
Missing neighboring relationship, cont.
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After dropped call:
UE is connected to the missing neighbour cell (SC 83)
Missing neighboring relationship, cont.
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dark blue = footprint W00528021
light blue = footprint W10646031
Planned site
Recommending Optimisation changes
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Add SC83 SC19
as neighbours Note: site 3978 is a
planned site.
Use .cel file to help tosee existingneighbour relations
Planned site
No coverage
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Symptom:
All radio performance are very bad performance
Best serving CPICH_RSCP is low, e.g. < -105dBm
Best serving CPICH_Ec/No is low, e.g. < -16dB
UE_Tx_PWR is high.
Normally, the UE releases the connection by itself.
After connection drop, the UE cant find any suitable cell for a while.
Possible solution:
The unique solution is to add new site.
No coverage,cont.
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Poor RSCP Level andEc/No Level
Drop after active set update
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Symptom:
Normally, the observed sequent messages in the UE side are:
UTRAN -> UE: Active set update (to request the UE to remove a cell, e.g.
SC281)
UE -> UTRAN: Active set update complete
UTRAN -> UE: Measurement Control (update neighbour list)
UE -> UTRAN: Measurement report (to propose to add7)
UTRAN -> UE: Active set update (to request the UE to add SC 137)
DROP.......(since no Active set update completion was sen after 12 secs )
The radio performances no matter DL and UL are very good.
Possible solution: No solution, check this problem with UE vendor.
Soft/Softer HandoverRadio Link Addition
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Radio Link Addition
and Radio LinkRemoval.
Reference:User Description and Engineering Guidelines75/1551-HSD 101 02/1 Uen B2
Ericsson AB 2003 - All Rights Reserved
Drop after active set update, Cont.
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BLER is getting worse
RF condition
is o.k.
Drop after active set update, Cont.
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No Active SetCompletion was sentafter Active SetUpdate.
PDP Context Activation Failure
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Symptom:
All radio performance are good
However, PDP Context Reject by
UTRAN.
Possible solution: No solution, check
this problem with Network equipment
vendor.
Good RFcondition
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BACKUP
RRC States
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CELL_DCH: In this state the UE has a dedicated connection to the Radio Access
Network. It is used: For services requiring Conversational QoS, like voice and video call, because the
strict time delay constraints can only be achieved through a dedicated connection.
For High bit rate PS services because these can only be achieved through adedicated connection
In this state the UE is in constant contact with the network which knows itsposition on cell level, because it communicates (via cell update) every time it
changes cell
CELL_FACH:In this state the UE does not have a dedicated connection to thenetwork relying instead on common channels (RACH./FACH) which it shares withother users It is used
For PS services that require the transfer of low amounts of data. If more capacity is
required the UE is promoted to CELL_DCH For signalling with the network
In this state the UEs position is known by the network on cell level
RRC States
CELL DCH: In this state the UE has a dedicated connection to the Radio Access
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CELL_DCH: In this state the UE has a dedicated connection to the Radio AccessNetwork. It is used:
For services requiring Conversational QoS, like voice and video call, because thestrict time delay constraints can only be achieved through a dedicated connection.
For High bit rate PS services because these can only be achieved through adedicated connection
In this state the UE is in constant contact with the network which knows itsposition on cell level, because it communicates (via cell update) every time itchanges cell
CELL_FACH:In this state the UE does not have a dedicated connection to thenetwork relying instead on common channels (RACH./FACH) which it shares withother users It is used
For PS services that require the transfer of low amounts of data. If more capacity isrequired the UE is promoted to CELL_DCH
For signalling with the networkIn this state the UEs position is known by the network on cell level
RRC States
CELL_DCH: In this state the UE has a dedicated connection to the Radio AccessNetwork It is used:
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Network. It is used:
For services requiring Conversational QoS, like voice and video call, because the
strict time delay constraints can only be achieved through a dedicated connection. For High bit rate PS services because these can only be achieved through a
dedicated connection
In this state the UE is in constant contact with the network which knows itsposition on cell level, because it communicates (via cell update) every time itchanges cell
CELL_FACH:In this state the UE does not have a dedicated connection to thenetwork relying instead on common channels (RACH./FACH) which it shares withother users It is used
For PS services that require the transfer of low amounts of data. If more capacity isrequired the UE is promoted to CELL_DCH
For signalling with the network
In this state the UEs position is known by the network on cell level
RRC States
CELL_DCH: In this state the UE has a dedicated connection to the Radio AccessNetwork It is used:
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Network. It is used:
For services requiring Conversational QoS, like voice and video call, because the
strict time delay constraints can only be achieved through a dedicated connection. For High bit rate PS services because these can only be achieved through a
dedicated connection
In this state the UE is in constant contact with the network which knows itsposition on cell level, because it communicates (via cell update) every time itchanges cell
CELL_FACH:In this state the UE does not have a dedicated connection to thenetwork relying instead on common channels (RACH./FACH) which it shares withother users It is used
For PS services that require the transfer of low amounts of data. If more capacity isrequired the UE is promoted to CELL_DCH
For signalling with the network
In this state the UEs position is known by the network on cell level
Physical layer AspectsCompressed Mode Methods
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Three methods are available to create transmission gaps
Puncturing: additional puncturing/fewer repetitions are performed comparedto normal mode to be used only in DL
to be used only in the case of mapping to fixed positions
scrambling and channelisation code remain unchanged
Spreading Factor Reduction: SF is divided by 2 can be used in UL and DL
can be used with mapping to flexible positions
to be used only when SF>4
only 2nd DTX insertion and physical channel mapping is modified
may lead to channelisation code shortage and the need to use a secondary scrambling code
Physical Layer AspectsCompressed Mode Methods
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Higher Layer Scheduling: only a subset of the TFCS is used during a compressed radio
frame to create the gaps can be used in UL and DL
can be used with fixed and flexible mapping
to be used only for radio bearers that allow some buffering, e.g interactive and background classes
rate matching remains as in normal mode
Use of Multiple Methods in Parallel There are generally no restrictions within the standard on the use of different methods when multiple pattern
sequences are used in parallel, however, some precautions must be taken. E.g., Compressed mode by puncturing affects the rate matching across the longest TTI in the CCtrCH while compressed mode by
higher layer scheduling works on a radio frame basis. For these two methods to co-exist, there must necessarily be a restriction thatthey do not attempt to put transmission gaps within the same time interval defined by the longest TTI of the CCtrCH.
Physical Layer AspectsPower Control (UL)
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Inner loop power control in compressed mode some commands are lost due to the transmission gap, aim is to recover
as fast as possible after the transmission gap
Initial Transmit Power (ITP) ITP = 0 : power after the transmission gap = power before the transmission gap
ITP = 1 : power after the transmission gap = average power before the transmission gap
Recovery Period Power control (RPP) RPP = 0 : same algorithm and step size applied as in normal mode
RPP = 1 : algorithm 1 is used with step size DRP-TPC = min(3dB, 2DTPC) during RPL slots = min (7 slots,transmission gap length) after the transmission gap
Physical Layer AspectsPower Control (UL)
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Outer loop power control in compressed mode
deltaSIR: offset to apply on UL SIR target during compressed frames
deltaSIR_after: offset to apply on UL SIR target one frame after the compressedframe
DPDCH/DPCCH power offsets are altered to keep the power on the pilotbits and information bits constant
Configuration ProceduresNBAP Procedures
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Compressed mode pattern sequences are configured in the Node B by the
RNC using the RADIO LINK SETUP REQUEST message
several compressed mode pattern sequences can be configured at thesame time
configuration can be done separately from activation
Activation is done either at Radio Link Setup or with a specific message
COMPRESSED MODE COMMAND
Reconfiguration is done with synchronised reconfiguration procedures
Configuration ProceduresRRC Procedures (Principles)
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Ke