Case study of WCDMA R99/HSPA for planet v5.2

Peter CheungTechnical Consultant,Mentum HK10 Aug 2010 (updated 20Feb2011)

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Summary• Set and configure soft launch site/sectors• Define subscriber setting

• equipment, service, subscriber type• Define environment• Create traffic map based on #sub or throughput demand• Run Monte Carlo for R99 and HSDPA carriers• Analyze Monte Carlo results

• # served subscriber• Throughput per sector• Examine unserved subscriber reasons

• Apply Monte Carlo cell load and re-run Network analysis• CPICH pollution• Area coverage % of different bearer

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backup• HSPA+ extra feature• HSPA/HSPA+ UE category• Bearer selection• MC setting

• Subscriber spreading• Activity factor• primary/secondary throughput

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1a – soft launch site/sectors group

Group “Mongkok_ wcdma” (green)

•Each sector has carrier 1 and 3, both R99 + HSPA carriers•Activate carrier 1 as R99 ONLY•Activate carrier 3 as HSPA ONLY

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1b – configure sectors for R99 carrierUse max 472 OVSF for R99 only traffic for carrier 1, with #R99 users = 100

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1c – configure sectors for HSPA carrierUse max 472 OVSF for R99 only traffic for carrier 3 with max # HS-DSCH codes=10 and max # HSPA user = 2#R99 OVSF codes = max #OVSF codes – 32* #HS-DSCH codesMax #OVSF codes = 512 – 40 = 472 [by default, with #OVSF for CCH = 40]

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1d – config site setting

Max pooled DL (i.e., traffic) per site for ALL carriers• split for CS and PS service throughput• represent offered backhaul transmission capacity• used for MC new subscriber served threshold

Total CE used for UL and DL per site• split for primary pooled throughput (i.e., traffic) and SHO for R99• used for MC new subscriber served threshold• represent baseband logical unit per site per carrier

Total CE = CE for primary pooled + CE for SHO

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2a – setup R99 and HSPA bearerDefine R99 DL and UL bearer for required Eb/No at FER=xxx%

Define HSDPA DL bearer à HS-DSCH Ec/NtDefine HSUPA UL bearer à E-DCH Ec/Nt

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2b – setup equipment

Both HSPA equipment, where• WCDMA-R99 MS has ALL R99 bearer but no HSDPA bearer• WCDMA-data-dongel has ALL R99 bearer + HSDPA bearer

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2c – setup services2x CS services (12.2K voice and 64K data) with specified individual loading and DL activity factor=50%

3x PS services (164K/128/384K data) with specified individual loading and DL activity factor=100%

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2d – setup subscriber typesR99 subscriber for outdoor usage for CS services with higher priority (1)

HSPA subscriber for indoor usage for PS services with lower priority (2)

10x scaling factor for BOTH subscriber type to “over-spread” subscriber from traffic map (i.e., to spread as many subscriber as possible)

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3 – setup environment• Enter fast/slow fading margin• map default 4x planet clutter type to clutter names from map• e.g., disable some clutter, no indoor for water clutter• set clutter dependent DL orthogonal % (100% = no intra-cell interference, 0% = intra is same as inter-cell interference)

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4a – Create traffic map

Tabulate site ID/sector ID/ # of sub as an excel file (ie.. Traffic target per sector)

Import excel file to planet and map column

Import excel to operational data

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4b – Create traffic map

Create CPICH best server

Create traffic map with unit #sub/km2 and select CPICH best server within mongkok area

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4c – Create traffic map

assign different weight factor per clutter class and generate traffic map

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5a – Run Monte Carlo

Run MC for 2x subscriber type within mongkok test area, and wait for MC run to converge within 5%

• Distribution of spread subscriber after MC runs converged

• after MC result is checked OK, apply cell loading (i.e., write traffic power % and noise rise back to sector config)

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5b – Examine Monte Carlo results• Subscriber per sector/carrier à examine block reason and # served/unserved subscriber• compare unserved % with KPI

CDF of # served subscriber

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5b – Examine Monte Carlo results

Global throughput MC report for different service/environment

PDF of throughput

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5c – Examine Monte Carlo results

Sort # served subscriber (from largest to smallest) for 1 combination of carrier/sub type/service/environment

Create sector display scheme to represent # served sub, apply to sector on map windows

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6a – CPICH pollution at environment xx and subscriber equipment xx

CPICH pollution between cells (at low CPICH Ec/Io, where no dominant CPICH presents), typically resolve by increasing antenna downtilt

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6b – coverage % for different bearer

Create statistics report based on HS-DSCH max achievable data rate and with • Analysis area = mongkok_area• Classified grid = best server grc file• Traffic map = xxx• Step size of data rate = 32k, 64k, 128k, 384k, 1M, 2M, 3M as different ranges

Optional map input to add extra columns in statistics report (e.g., best server grc, traffic map)

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6c – coverage % for different bearer

e.g., top 10x sector with highest coverage area % within polygon within 2M~3M data rate range

e.g., area coverage % for different bearer of HS-DSCH

backup

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Example of WCDMA network design

KPI Min/max target % areaCPICH Ec -100dBm min -85dBm 80CPICH Ec/Io -15dB min -10dB 90SHO overhead 40% max 30% 902 way HO 25% max 20% 903 way HO 12% max 8% 90DL coverage (based on highest throughput)

70% 90% 90

# CPICH polluter 5 max 0 90

Interference problem• CPICH Ec/Io à cell isolation/interference, commonly resolve by Etilt and antenna type• CPICH polluters à non-dominant CPICH with Ec/Io > threshold, • CPICH coverage is independent of loading %• common for indoor and high/umbrella site (also needs to reserve PSC for those sites)

Coverage problem• limit on DL power and CPICH RSCP, as traffic increase

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HSPA+ extra feature (1)HSPA+ support if • carrier supports HSPA/HSDPA• HSPA is activated in respective sector• HSPA+ terminal is defined in HSDPA terminal category (extra cat 13~24 for HSDPA and cat 7 for HSUPA)

Extra HSPA+ feature (3GPP rel 7)• 64QAM (UE cat 13, 14, 17~20, 23, 24)• DC-HSDPA (for UE cat 21~24) if adjacent carrier is available• 2x2 MIMO (for UE cat 15~20)

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HSPA+ extra feature (2)

2x2 MIMO

• 2 Tx NodeB antenna and 2 Rx UE antenna• depending on HS-DSCH Ec/Nt, data rate gain is tabulated (i.e., open loop MIMO)

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HSPA+ extra feature (3)

Common layer “DC-HSDPA data rate” is generated as sum of 2 highest HSDPA data rate for adjacent carriers

64QAM modulation is supported for specified UE category if sector has 64QAM enabled for HSPA+ capable carrier

Ec/Nt = Eb/No – 10*log10 ( 3840 / bearer service data rate)

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HSDPA UE category

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HSUPA UE category

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HSDPA TFRC and HSUPA FRC

HSDPA TFRC

HSUPA FRC

e.g., max 16QAM 15codes throughput = 3.84/16x4x15=14.4Mbps (SF=16 fixed)

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Sector loading All loading parameter are used for network analysis calculation and is obtained by• initial guess for scenario planning• MC output result

Tradeoff between coverage and capacityUL loading % = 1- 10^ (-UL noise rise/10)

Traffic power loading % for DPCH (R99) and HS-DSCH (HSDPA/HSPA) is relative to available traffic power

• represent bursty nature of HSDPA PS tx• used as scaling factor to calculate

HS-DSCH Ec/Nt

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Sector power partitionDL total power = PA power

= CPICH + SCH/P-CCPCH + other common control

+ DPCH min..DPCH max (R99)

+ HS-SCCH (HSDPA)

+ HSUPA ctrl (HSPA)

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Concept of channel element• For voice bearer

• Typically 1 CE for 1x 12.2kbps voice bearer• For each sub, add 1 CE to best server and all HO sectors• Same process for both UL and DL

• For data bearer• Add #CE from bearer definition LUT• For each sub, add #CE to best server and all HO sectors• Same process for R99 DL, R99 UL, HSDPA UL• No CE concept for HSDPA DL and HSUPA UL

• Repeat until total # CE at NodeB runs out (e.g., sub can be blocked by CE even for good channel conditions)

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MIMO for HSPA+ (cat. 15~20)

HSPA+ (release 7) only supports 2x2 MIMO• 2 tx antenna at NodeB• 2x Rx antenna at UE• depending on HS-DSCH Ec/Nt, apply throughput gain LUT relative to SISO• NOTE: in current planet v5 version, 64QAM is disabled in cat 17/18 if used

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DC-HSDPA for HSPA+ (cat 21~24)

DC-HSDPA• supports only if it is enabled in HSPA activated technology • represent sum of 2 highest throughput of adjacent carrier in the same network analysis• NOTE: dual band HSDPA is not supported in current planet v5 version

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Soft/softer HO

Soft HO if• for R99 carrier sector ONLY• up to max of 7 HO sectors can be supported by UE (i.e., # of RAKE fingers)• sectors considered for SHO if

• sector CPICH Ec within HO margin• sector CPICH Ec/Io > target CPICH Ec/Io• softer HO is within max intra-site servers

• affect layers for HO status, SHO gain and # active server counts• tradeoff à more # HO servers, UE can reduce Ptx, decrease UL noise rise BUT increase NodeB Ptx and DL SHO overhead CE

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Comparison of bearer• Release 99: Dedicated channels in Downlink and Uplink

• HSDPA (Release 5)• Shared downlink channel (TDMA), implementing new techniques• Uplink remains unchanged

• HSUPA (Release 6)• Downlink identical to HSDPA• Implementing the same techniques (more or less) in the Uplink

DL DPCH 1

UL DCH 1

DL DPCH 2

UL DCH 2

HS-DSCH

UL A-DCH 1

HS-DSCH

UL A-DCH 2

HS-DSCH

UL E-DCH 1

HS-DSCH

UL E-DCH 2

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Comparison of HSDPA/HSUPA

HS-DSCH Ec/Nt, where

Ec = HS_DSCH power from best server available for HSDPA usersNt = out-of-cell interference (from ALL sector /ALL channels except best server)

+ in-cell interference x (1- orthogonal %) + thermal noise

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R99 bearer settingDL bearer setting UL bearer setting

Target FER % defined per service, if not found, interpolate to extract required Eb/No

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HSDPA bearer setting HSDPA DL with multi-codes with required HS-DSCH Ec/Nt MCS tablee.g., to convert to vendor SINR MCS table [e.g., ericsson] = Ec/Nt + 10log (SF16 * M) = Ec/Nt + 12dB + 3dB (for QPSK) = Ec/Nt [planet table]+ 15dB for QPSK for 1 code

HSDPA UL with for 64/128/384kbps with Eb/No for target FER %

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HSUPA bearer setting

NOTE• ALL MCS table does not consider log-normal fading (i.e., 50% cell coverage prob).

• During calculation of HS-DSCH max throughput, its coverage prob of each MCS based on log normal std.dev is compared with target cell edge prob

• max achievable data rate = highest MCS with its coverage prob > target cell edge prob

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HSDPA scheduler

Schedule gain curve • relative to equal time round-robin (i.e. 100% gain)• increase overall sector throughput at the expense of serving sub fairness• gain “flat-out” when # sub increase to some threshold• proportional-fair scheduler increase gain from 100% to 200% for first 10~16 sub in urban environment by serving a sub with better channel conditions (i.e., “upfade”), BUT have large data rate fluctuations between different users

Different scheduler gain curve

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MC – bearer selection• Bearer is selected if

• Supported by carrier type (e.g., R99 UE not supported in HSDPA or HSPA)

• DL Service data rate within min/max range• UL service data rate within min/max range

• DL/UL activity factor• Associated with min required data rate of service• Primary direction = DL if

• (DL AF x min DL throughpu)t > (UL AF x min UL throughput)• Otherwise primary direction = UL

• Service and carrier dependent, eg R99+HSPA carrier• PS service carried by HSDPA bearer first• CS service carried by R99 bearer first• For multiple service, sort by sub service priority• NOTE: if different CS/PS service with same priority, R99 sub service

should get served first (i.e., generate UL DPCH noise rise)?

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MC – bearer negotiation • Overall

• Process of reducing data rate from maximum MCS given radio channel conditions

• Apply for both CS and PS service• If GSM sector is available, sub may downgrade from WCDMa to

GSM. If no GSM is supported, sub is dropped by priority• # served users in MC result

• Non-negotiated # served users• Both DL/UL services use highest throughput bearer

• DL negotiated # served users• DL bearer negotiated to lower throughput, but UL bearer is at highest

throughput• UL negotiated # served users

• UL bearer negotiated to lower throughput, but DL bearer is at highest throughput

• Negotiated # served users• Both DL and UL bearer negotiated to lower throughput

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MC – traffic class for negotiation

Different traffic class have different data negotiation rules

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Example (1) – CS384 service with HSPA UE

MC Input• Carrier has R99+HSPA• UE has R99 + HSPA+ bearer enabled• CS service 32~384k (DL), 32~64k (UL) @FER/PER=1%• target cell edge prob = 85%• all DL/UL R99 bearer enabled (12.2~384k) and HSDPA UL bearer

MC output• CS service served by R99 bearer first• no HS-DSCH bearer used in this case• R99 DL/UL bearer used in primary (traffic with best server)• R99 DL/UL bearer used in secondary (traffic with SHO)

Throughput MC result for different environment

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Example (1) – CS384 service with HSPA UE Negotiation status

Sub blocked reason

e.g., blocked by UE PA power (UL coverage prob below target)

e.g., UL negotiated and reduce data rate from R99 384k bearer (max) to 32k (achieved)

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Example (2) – PS384 service with HSPA UE Throughput MC result for different environment

MC Input• Carrier has R99+HSPA• UE has R99 + HSPA+ bearer enabled• PS service 32~384k (DL), 32~64k (UL) @FER/PER=1%• target cell edge prob = 85%• HSDPA UE category class 5

MC output• PS service served by HSDPA bearer• HS-DSCH for DL and A-DCH for UL• no R99 bearer used in this case• HSDPA DL/UL bearer used in primary (traffic with best server)• HSDPA DL/UL bearer used in secondary (traffic with SHO)

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Example (2) – PS384 service with HSPA UE Negotiation status

Sub blocked reason

e.g., Sub block by HS-SCCH power

e.g., Sub block by CPICH power (i.e., RSCP below target)

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Example (2) – PS384 service with HSPA UE Negotiation status

Sub blocked reason

e.g., DL negotiated and reduce HSDPA data rate from HSDPA UE class 5 4320k bearer (max) to 1280k (achieved) according to HS-DSCH Ec/Nt values

HSDPA bearer DL negotiation

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Example (3) – mixture of CS/PS service with R99 UE and R99+HSPA UE

MC Input

• Carrier has R99+HSPA• 3 sub type with different priority• sub type 1 = R99 UE + CS12.2k service• sub type 2 = R99+HSPA UE HSDPA cat 5 + CS384k service• sub type 3 = R99+HSPA UE HSDPA cat 5+ PS384k service

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Example (3) – mixture of CS/PS service with R99 UE and R99+HSPA UE

PS service served by HSDPA bearer (HS-DSCH)

PS service served by HSDPA UL bearer (A-DCH)

• SS service served by R99 UL/DL for primary (traffic) and secondary (SHO) sectors