3CO(Supersizing CDMA) v1.2

8/8/2019 3CO(Supersizing CDMA) v1.2

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3G Capacity Optimization-3CO(SUPERSIZING CDMA)

In mobile originated calls, mobile terminated calls, handoffs, and the receiving & transmitting of SMS on TCH,traffic channels or any other resource can not be successfully assigned which will foster a call assignment

failure/blocking. Following are the Blocking reasons at BTS level with quick short term and long term remedies.

Caution: Parameter setting recommendations given in this document should first conform to vendor guidelines, andvalidation testing is needed after every change to verify the objective is achieved without causing other side-effects.

1) Spreading CodesShortage (Walsh Codes)Make sure that we have max # of WC resources available that is allowed by the standard and are not restricted byconfiguration Management.

1) Inhibiting high soft HO ratio (analyzed through (CE Erl- TCH Erl)/TCH Erl)a. Physical Optimization (down tilt), maintain pilot dominance (check through drive test).b. Enable the Dynamic Soft Handoff Thresholds by setting proper values for SOFT_SLOPE (2 dB to 3

dB), ADD_INTERCEPT (0 dB to 3 dB), and DROP_INTERCEPT (0 dB to 3 dB).c. If Dynamic Soft Handoff Thresholds are not enabled, set higher values for T_ADD, T_DROP, and

T_COMP; and set a lower value for T_TDROP for highly loaded sectors. For example, set -12 dB forT_ADD and -14 dB for T_DROP, and set T_TDROP to 2 seconds for the highly loaded sectors in anembedded network.

2) Inhibiting Softer HO ratio (analyzed by (WC Erl-CE Erl)/CE Erl)a. Physical opt. especially increasing the azimuth angle between sectors with softer HO ratio> 30%.b. Checking the terrain for any increased reflections back which sets antenna to self oscillation.

3) QOF (Quasi-Orthogonal Functions)a. It enlarges the number of code channels on the Fwd link. Though they reduce the ortho space. Using

a total ofMmasks with Walsh codes of length n, the Forward link code signal set size is (M+1)n.CDMA2000 uses M=3. i.e. WC can be increased to 256 by using this inherent feature of Rel 0.

4) RRM/LC Algorithm Inter-working:a. One 16X data service call occupies the resources equal to approximately 20 voice subscriber

services. Higher data rate channels use shorter length Walsh codes to maintain a constant chip rate.Using one of the shorter Walsh codes precludes using all longer codes that contain the bit pattern ofthe shorter code. So, decrease of the rate of high-speed data service can effectively reduce the celloverload when the cell is overloaded. This is something that overload control algo (discussed later)needs to incorporate and verify.

b. We have to check if RRM & RRC algorithms are working harmoniously i.e. Forward/Rev SCHadmission algorithm & SCH distribution strategy (discussed later).

5) Walsh Code Tree Managementa. Also see if vendor is using some proprietary algorithm for WC tree management

6) Sector splittingThere might be cases where adding sector is resorted to pump in more Walsh. Unlike theconventional 2G technology of which tele-traffic bearing capacity is limited by frequency (channel)allocation, the tele-traffic bearing capacity for CDMA is limited by interference.

a. S11 sites to S111 (no problem)b. S111 to S1111.

i. Care needs to be made as the effect of adding more WC will be nullified by high softer erl asazimuth angle is reduced between sectors. Needs to use smaller beam width antenna. In turn,narrower beam width antenna provides higher gain and better link budget and largercoverage area.

ii. Morphology factor: This sort of sector addition is more suitable for rural case, but for urbanareas more sectors will generate infect more interference between sectors and trueadvantage cant be used effectively. Also in rural areas we have more PN reserveassignments as compared to Urban.

c. S111 to S111111


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i. From the air interface standpoint, a 6-sector configuration provides almost double the Erlangcapacity than the tri-sectored scheme. The benefit suffers from a diminishing return due tothe additional interference. From the Erlang capacity standpoint, no trunking efficiency can berealized from this deployment. Hence it is not at all recommended.

7) Add new carriersa. Limited by carriers bought during initial auction. If all carriers assigned are already in use then may be

new carrier can be bought from other operators/regulator. This is the best solution as it will increaseoverall capacity of entire region and may swayed away any requirement for new BTS site which offcourse has lot of capital expenditure involved.

b. From a capacity standpoint, even an un-orchestrated multiple carriers deployment multiplies thecapacity of the network. With intelligent resource allocation scheme, the traffic loading among multiplecarriers can be intelligently managed to increase the trunking efficiency of the network. It results inmuch higher aggregated Erlang capacity and better system redundancy.

8) Add new sites (cell splitting)a. Long Term solution. The decision to add a site in an area where already there is a CDMA cell site is

a tricky one and needs to consider long term traffic trend plus inputs from sales/marketing.

2) Power Amplifier Blocking (Improving Forward Soft Capacity)To understand your PA resources you need to see how PA mechanism is implemented. What are the technical specsof PA i.e. minRatedTxpwr, de-rated maxTXpwr, ratedmaxTXpwr, protection features etc. They following solutions aredifferent ways to improve forward link soft capacity within fixed PA allocation.

1) Inhibiting High Soft HO ratiosa. An appropriate range exists that balances quality and capacity vs. power requirements. However, if

that balance isn't maintained, the imbalance "chews up" system resources trying to deal with thehandoff process. The way to tackle this problem is already discussed.

2) Overhead Power Check:a. The pilot power should not occupy too much of the power(20%), If a base station sector lacks HPA

power on traffic channels but RF coverage is sufficient, one can consider reducingMinPilotToTotalPowerRatio between 0.5 dB to 1 dB.

b. Other Overhead channels should have the power assignment at level defined in Qualcommrecommendations.

3) Improper forward power control Settinga. For sectors running out of forward linkcapacity, one can consider lowering the FPC_FCH_{INIT, MIN,

MAX}_SETPT settings to {2 dB, 3 dB, 7 dB}, respectively. Setting the FPC_FCH_MIN_SETPT toolow (1 dB) is not recommended because it increases recovery time if amobile moves out of good RFcoverage too quickly and unnecessary droppedcalls might occur.

4) Forward Quality Parametera. As forward link is stronger than reverse, we can relax the FER requirements on forward link from 1%

to say 2~3%. This will ease the forward power/TCH.b. Forward interference (eliminate interference). This can also effect power control performance as MS

will have problems hearing BTS and Fwd closed loop will increase the forward TXPO. Typicalsignature is reasonable RX and very bad EcIo.(needs to do DT).

5) Equipment aging with timea. Antenna Aging Checks: Carry out basic RF CDMA test on current antenna to gather its aging affect

e.g. Beam Squint, Beam Tracking, Sector Power Ratio, Null filling, antenna roll off.b. Antenna inter-modulation: Make sure that your system's antennas are designed robustly enough

that their inter-modulation (IM) performance does not decrease with time. The IM performance ofdesigns using multiple cables and solder joints are susceptible to deterioration once the antennas areplaced in an outdoor environment. Many antennas do not even meet their advertised IM specificationbefore being placed on a site

c. Feeder path problemThis can also affect the ERP. Use site master to check the VSWR is within limits. Too high VSWRcan also limit the HPA performance.

d. Antenna Efficiency CheckVSWR tells us how well the product's impedance matches to (absorbs) a transmitters signal, and it iseasy to measure in the field. Unfortunately, VSWR does not reveal an antenna's efficiency (how well


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it radiates the signal). This measurement (an antenna's radiation pattern) is more difficult to performin the field. We may presume that match bandwidth and pattern bandwidth are equal, but this is notalways true.

1. Judging any degradation in the antenna pattern. It is a good idea to documentperformance upon installation. This is usually done by choosing a remote site andmeasuring the signal level received from the transmitter. Periodic measurements atthat same location will reveal the amount of any degradation so that corrective actionmay be taken

e. HPA Aging: You will have too frequent HPA blocking whereas HPA never reaches the max ratedpower. This can also be due to continuously bad VSWR which can be measured by Site master.

i. BSC Power tracing function: We need to run real time power trace to see its behaviorduring BH. If it is constantly above 44dBm for 60% of time during BH and there is as such nooverload protection applied and we actually have PA blocking during that time then thisneeds to be addressed.

ii. BTS Tester OTA measurements: Verify that the Avg Amp Cap is < 75 %(15W=41.7dBm)and the Avg Util is < 12.5 %.(if not then problem). This condition indicates that a significantamount of RF amplifier capacity is being allocated to a low number of mobile units.

6) Overshooting Sectors-Link Imbalancea. As per Plan: Please see the initial design and drive test results, if site is showing more coverage than

it was originally designed for, then needs to do physical opt.

b. Boomer Site: Link imbalance areas typically can be identified if the forward link coverage is sufficient(good pilot Ec/Io) but call setup failure is high due to exhausted mobile transmit power on the reverselink. Needs to act accordingly by doing Physical Opt.

c. Applying Attenuation: Apply attenuation loss to the BTS antenna (by using pads or parametersettings such as TxPowerLimitOffset)

7) Improving RF Environment:a. Pilot Pollution mitigation: Optimization effort needs to be put in to improve RF environment for

subscribers. We should try to have areas of pilot dominance and try to min pilot pollution regions. Toavoid pilot pollution, operators can use antenna down tilt, azimuth rotation and careful horizontalbeam width selection. Other methods of reducing pilot pollution used less extensively includelowering cell site heights, lowering cell site power and using repeaters.

i. Better EcIo on fwd translates into improved forward capacity For higher combined Ec/Io,lower traffic channel Ec/Ior is required and more BTS HPA power is conserved to

accommodate more users in the samesector. Typically, a 1 dB BTS Tx power reduction foreach voice channelincreases RF capacity by approximately 15% for any given BTS sector.

b. Improving indoor coverage Too many indoor users can consume too large power resources on fwdlink. To help this situation we need to use specialized indoor active/passive repeaters, micro sites.

8) Overload Control Algorithma. Gain Clipping Algo

i. Following is the condition for this algoSCH_Setup < Call_SETUP < T_HO < T_PWRUP,

If the Tx power (RFPower) in a carrier sector meets the following condition, the sector willenter level 1 overload CELL_PWR*T_SETUP/100 < RFPower CELL_PWR*T_HO/100 (i.e18


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means when power has crossed MAXTXPWR and power limiting algo/attanuation has beenapplied (to reduce the HPA power-) but still the power reqd keeps on increasing and wereach max att setting. Now it cannot be att any further. This is max wilting. Beyond this pointHPA can be damaged. Now it needs to blossom to come down to 43dBm.(some callsdopped). Are we using attanuation settings in our system to do cell wilting/blossoming whenHPA power limit is crossed

9) Load balancing Algoa. Intrafreq Inter site load balancing (cell breathing):

i. Load control module performs timing statistics on the load. When load level of certain onepilot exceeds the threshold, the system will judge the load of the pilots neighbor pilot. If theneighbor pilot is in under-load status, the system will increase the power of neighbor pilot anddecrease the transmitting power of this pilot. When the pilot overload disappears, the systemwill recover them. Forward link will be reduced to cater for cell shrinkage on reverse link(reduced Rx sensitivity) due to increased loading. This feature can be enabled at BSC.

ii. However we should make sure that sufficient overlaps so that not clear holes whenshrink(30% SHO)

iii. Breathing should always be disabled for boundary sectors.Breathing of boundary sectorsmay result in uncertainties of which target sector a mobile station should handoff too.Boundary sectors will be unlikely be heavily loaded in most cases

b. HASH Algo: Also check if HASH is on to automatically balance the load between different carriers of

same site.c. Inter Carrier Wave Intra Site Load balance algorithms (Vendor specific)

i. ZTE two parameters for overload control and load balancing are Carrier call threshold (ofcurrent carrier)=15, Threshold of changing carrier(interfreq assignment threshold)=3. It isnecessary to first make an admission judgment before the channel assignment.

ii. We can disable access/paging on one carrier and hence it cant be assigned the firsttime(made least favorable). But after primary carrier is filled with some traffic then interCarrier assignments start. (vendor implementation).

d. Targeting Orientation based on traffic stats-Raw Load balancing techniquei. Changing antenna beam-widths and orientations is also used to balance the loading on a

particular site. For instance, on a three-sectored site, one sector might be facing directly at acongested highway interchange, while another sector on the same site faces a little-usedpark area. By widening the beamwidth of the little used sector and narrowing the beam-width

of the heavy sector, the number of simultaneous users per sector can be more evenly spreadout, allowing for more capacity on the site as a whole.

10) Trunked PA:a. If vendor supports it then this is very good solution for supporting PA requirements of heavy sectors.b. But still how much a sector can get needs to be optimized to keep up the fwd/rvs balance.

11) Dual Receive Antenna:a. Forward link capacity can be expanded through dual receive antennas in the mobile terminals. If is

fully implemented in all mobiles, it is possible to realize a forward link voice capacity gain of nearly 2.5dB(80%). Terminal receiver diversity improves C/I. Better C/I results in lower base station powerallocation to each user. Also it depends on whether Minimal Mean Square Error (MMSE) combiningscheme or Maximal Ratio Combining (MRC) scheme, is implemented.

12) Transmit Diversity Techniquesa. Orthogonal Transmit Diversity (Rel 0) Using transmit diversity in the base station would yield some

capacity gains, but at the cost of additional transmit chain requirements. The transmit diversityschemes would provide better gains in astationary or pedestrian environment.b. Space Time Spreading (Rel A) Space Time Spreading (STS) is a Forward link transmission method

that transmits all Forward link channel symbols on multiple antennas and spreads the symbols withcomplementary Walsh or Quasi-orthogonal Functions. This results in a lowerEc/Ioat low velocities,particularly with one path Rayleigh fading. It requires special Space Time Spreading [STS] Pilots,auxiliary Pilots,

c. Which is better: OTD uses two antennas witheach antenna transmitting half the data, whereas STSuses two antennas with each antenna transmitting all data. The STS scheme appears to havesuperiorperformance, but that comes with higher complexity and cost.


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3) Channel Element ChockingIt cannot assign the CE because BTS is short of CE resource. We need to see directly from system what is the actual# of CE available per carrier level and not rely on BoQ numbers.1) Under-planned CE

a. The channels are not well planned, traffic model assumptions no more remain true

2) High Soft HO ratioa. The soft handoff ratio is so high that too many CEs are occupied (than planned for). Normally if a sitehas 50% SHO ratio and its carrying 60 Erl TCH/carrier group then there might be chances of SHOassignment failure due to CE shortage.

3) CCM wait timer timeouta. For the intra-BS soft handoff and the inter-BS soft handoff, the insufficient channels in the traffic

measurement may also result from the CCM wait timer timeout and unsuccessful resourceassignment due to other exceptional causes. Do consult its value from the vendor.

4) CE board problema. Might be some HW or SW problem which is inhibiting the use of certain CEs or all CEs per board. We

have to run a proper trace or board replacement to verify it.b. CE inhibited during OCNS, but operator has forgotten to re-inhibit it.

5) CE sharing across carriersa. It can reduce the strict requirement of configuring equal # of CE /carrier in a site. But this has to

implement with load balancing mechanism to balance traffic between 2 carriers.b. Even with load equalization, there might be a possibility that all high data users have been assigned

one carrier. In that case, congestion can be mitigated by using this approach.

4) Insufficient Reverse Capacity (Maximizing Reverse Soft Pole Capacity)The following solutions are to improve reverse link soft capacity. This is the area which has gained maximum

attention of researchers. This is where the commonly used capacity, coverage, quality tradeoff of CDMA lies.1) Reverse Call admission control-Voice(CAC):

a. "Load Forcast/prediction" Algo :When the system assigns channels, it will first predict the totalequivalent RC3 voice subscribers, and then judge if the number of the total RC3 voice subscribersexceeds REV_MAX_USER (static/ dynamic) (reverse subscriber admission threshold=Huawei,Callcomthreshold=ZTE). If so, the channel assignment will fail and the system will be considered thereverse power is insufficient in the traffic measurement

b. Cell breathing & CAC inter-working Extent of cell breathing can be controlled by CAC, which decideon the basis of cell Noise Rise which calls can be accepted.

2) Call Admission Control - Data (SCH distribution Strategy)a. Forward SCH Allocation Algo

i. Perform admission control according to load admission threshold under the rates for center area,middle area and border area respectively.

1. Border area(4x max): Ec/Io < BORDER_PLT_THRESH2. Middle area(8x max): BORDER_PLT_THRESH =< Ec/Io < CENTER_PLT_THRESH3. Center area(16x): Ec/Io >= CENTER_PLT_THRESH

b. Reverse SCH Admission(like Voice)-Normalization methodi. Normalization subscriber method is used. It normalize all current calls and soft handoff tributaries

to DC3 voice subscriber number according to RC, rate and service types (voice service or dataservice). Reverse SCH admission judgment: if the sum of the existing channel normalization

subscriber number + newly distributed channel normalization subscriber number is lower thanREV_MAX_USER, the admission is successful; otherwise, the admission fails

3) Reverse power overload control algo:a. ROC(RSSI only-no call if measured ROT crosses some fixed threshold say 6dB)b. IROC (A specialized algo that considers Walsh code assigned RFER and Reverse ROT simultaneously.

If say there are fewer number of users, and/or if the RFER is low, then a greater RSSI rise over NoiseFloor is allowed before any blocking conditions are implemented.)


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4) Access Parameter adjustmenta. We can see the product of # of access probes to Num_Step should be equal to the max TXPO capability

of the MS. If not then MS may not be able to tx at its peak power during access.5) Reverse closed loop power control settings:

a. We can optimize the initial, min and max set points used in Rev closed loop power control.b. Outer loop parameters also need to be checks like EbNt adj step, FER reporting

6) Quality settings (RFER)a. By easing the RFER requirement we can fill in more user within the interference margin configured.

(ROC algo).e.g. changing from 1% FER to 2% FER can actually increase the # of users on reverse link(keeping within the NR margin) to 50%(depending on user distribution).

7) Silent re-originationa. The mobiles will autonomously re-originate calls that failed in their access attempt without user

intervention. This is akin to an automatic redial on access failures.8) Techniques to improve Access Probability

All these techniques will come in handy whenever there is some signaling failure during a call setup due to badRF link, reselect better PN during access. Hence reduces the prob of Congestion failure due to rev power.

a. Access Entry HO (Before sending an Origination Message or Paging Response, the MS performs apilot search and hands off to the adjacent BSS with better pilot strength. On the new BSS, the MS thensends an Origination Message or Paging Response .i.e paging on one pilot and response on anotherpilot.)

b. Access probe HO (sends the Access probes to different sectors or different Base Stations. The Accessattempt remains in progress until the mobile receives an acknowledgment to any probe sent during theAccess attempt or until the maximum # of probes is sent)

c. Access HO (act of transferring reception of the Paging Channel from one Base Station to another whilethe mobile is in the System Access State, but after an Access attempt. Mobiles are allowed to listen toanother (stronger) sector, other than the primary sector, for the Extended Channel Assignment Messagefrom the cell site. The mobiles will report the"" Access Handoff List"" on the Page Response Message orthe Origination Message listing all the strong pilots it measured. This list of pilots forms the secondarypilots. The cell site will subsequently transmit the Channel Assignment Message over the primary sectoror may be the secondary sectors. If an Access Channel handoff occurs, a new access sub attempt isstarted.)

9) Interference Margin optimization-soft blocking Limit(Static case-ROC algo)a. For coverage limited cases smaller interference margin is suggested while in capacity limited cases a

larger interference margin is suggested.b. We can set different Noise Rise limit for different sectors. For remote site set it to 8dB, urban=6dB

10) Reverse interferencea. Out cell Interference (from heavy loaded NHBR sites- Needs to balance load across sites)b. External Interference (Can eat up lot of reverse capacity- Needs to identify the source)

11) Diversity Techniquesa. Space diversity In rural areas space diversity is preferred over polarization diversity as different links

are more de-correlated at greater distance than can be provided by bipolarization antenna alone. Alsonormally signal doesnt arrive at difficult geometry angles.

b. 2-way/4 Way receive diversity Reverse link capacity can beenhanced through 4-way receive diversityin the base station. In reverse link capacity of 60% to 70% (around 2 dB capacity gain) can be achievedusing 4-branch/way receive diversity in the base station. A 4-branch cross-polarization (x-pol) diversityscheme would improve the pilot signal-to-noise ratio (SNR) by an average of 2.2 dB. For best

performance, the QUALCOMM CSM6800 (and above) chipset supports 4-way receive diversity in theinfrastructure. The QUALCOMM CSM5000 chipset also supports this feature, but with sub-optimalperformance.

12) Reverse pilota. Advantage:

Reverse pilot will eases reverse link so to increase the capacity in reverse link.. Reverse pilot can help alot in the initial call setup signaling to save the call at marginal RF coverage and it may be operating ingated mode to conserve power.

a. 1/8th rate gating on the reverse fundamental channel (control hold mode) If the CDMAoperator observes a capacity imbalance through reverse linkcapacity limitations in their network,


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the immediate solution is to implement 1/8thrate gating on the reverse link traffic channels.Gating can be enabled ordisabled on an MSC-wide basis. During gating, the mobiles transmitduty cycle is 50% and both reverse pilot and fundamental channels (R-PICH and R-FCH) aregated. Gating is not allowed during reverse supplemental channel assignment. 1/8th-rate gatingprovides reverse link capacity gains and increases the talk time of the mobile (by reducing powerconsumption during talk mode). The only drawback of this feature is some loss in the forward linksystem capacity due to the reduced forward power control (FPC) update rate. When gating isenabled, the power control rate is reduced by one-half, which yields a slight increase in the BTSpower allocation per traffic channel. Gating increases handset talk time by approximately 10%.Assuming 40% voice activity, 1/8th-rate gating would provide about 0.8 dB of improvement (up to15% capacity gain) to the reverse link Ec/Nt values.

13) Receiver Chain optimizationa. MHA (Mast Head Amplifier)

i. To reduce the Noise figure at BTS side and hence improve the RX sensitivity. In effect this willimprove the reverse link coverage area. The Tower Mounted Amplifier system solves thisproblem by improving system sensitivity by as much as 5 dB, thus increasing the base stationsector range by as much as 40%

b. Super Filtersi. An increasingly popular solution, with around 12 dB of gain and a noise figure of .4 dB, is

superconductor-based receive filters and ultra low noise amplifier systems, also called cryogenic

receiver front-ends (CRFE) or Super filters. These sharp filtering systems eliminate out-of-bandenergy that might have generated an in-band intermodulation product as well as add gain withan extremely low noise figure.

c. Duplexeri. Duplexers are generally at the front of the receive chain and have an enormous impact on quality

of service if their noise figure and isolation are not ideal. Different manufacturers' duplexers andcomponents may have noise figure differences of only tenths of dBs, but these losses add up,and quietly steal capacity, range and quality of service. Even if the difference from one vendor toanother is only .5 dB, this difference on a very heavily loaded multiple CDMA channel basestation can mean very noticeable degradations in performance.

14) F/R-DCCH for data/signaling(Rel 0)a. It is discontinuous, or DTX, and the data rate is fixed. The advantage of this type of operation is that the

channel is only transmitted when there is data to send. This generates less interference in the system,

which raises the overall capacity.

5) Other causes (Floor link/Interface congestion)1) A(A1/A2) interface transmission link establishment failure

a. Transmission fault, interrupted transmission, unstable DRS/microwaveb. CIC mismatches while defining links at both officesc. Insufficient capacity of A interface linksd. SS7 link capacity reached

2) Abis interface transmission link establishment failure:a. same as above

3) A3 interface transmission link establishment failure:a. During the inter-BS soft handoff, the target BSC needs to connect A3 interface and Abis interface to

realize the service transmission between MS and BSC after receiving the A7-Handoff Request message

at A7 interface. The failure may be caused by the improper setting of CCM_T_WT_BOOK_TIE_CNFtimer or the transmission link fault.


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Advanced Capacity Enhancements Solutions1) MS enhancements

a. 2-way/4-way receive antenna diversityi. Already discussed

b. Quasi-Linear Interference Cancellation (QLIC) (increase soft capacity by 30%)i. In CDMA networks, the pilot consumes a sizeable fraction (15% to 20%) of the total transmit

power, and it is fairly easy to learn the pilot symbols pattern. Understanding the spreading codesof signals coming from different sectors on the forward link can be used for interferencecancellation. Hence, the Pilot Interference Cancellation (PIC) technique is fairly easy to apply.Moreover, forward link interference cancellation on all channels would enhance the interference-limited capacity of the forward link. Thus, it is advantageous to implement interferencecancellation on all channels. Quasi-Linear Interference Cancellation (QLIC) is a proprietaryscheme used for of both pilot interference cancellation and traffic interference cancellation. ThisQLIC feature is expected to be available in future releases of the QSC chipset product line.

c. 4GV Vocoders (On fwd=40%, on Rev=23% soft capacity increase)i. What it does: select the best average Vocoders rate at a given time of the day, to address

varying demands with optimal quality of service. This enables CDMA operators to controlcapacity and voice quality, based on the time of the day (variable) demand. The number of voicecalls in a sector with 4GV is equal to the number of voice calls in a sector with EVRC times thePower Margin increase due to rate reduction.

ii. Implementation: QUALCOMM chipsets MSM 6100 and above, except for the QUALCOMMSingle Chip (QSC), support 4GV. It is expected that by the end of 2006, very low end (VLE)CDMA2000 mobiles with QSC (MSM6000, MSM6020, and MSM6030) would support the 4GVVocoders. From a network infrastructure perspective, the BSC needs only a software upgrade tosupport 4GV.

2) BTS enhancementsa. Transmit diversity (OTD/STS)

i. Already Discussedb. 4GV Vocoders,

i. Already Discussedc. Interference cancellation-Multi-user Detection

i. By using this technique we can de-spread multiple users at the same time instead of single userdetection technique conventionally used. Advantage is that by using Walsh Codes that were

assigned in that sector, we can get the actual users (simultaneous). Hence BTS can separateNoise generated from the cell to the one coming from out of cell.

d. Smart Antennasi. No deployment as such anywhere. But it is a concept of spot beam and requires auxiliary pilot

(Rel A) which will be spotted to individual user hence improving its demodulation condition.3) Suggestion for using advanced enhancements:

a. Combination of 4GV, QLIC, and 1/8th-rate gating would be a good choice for initial phase capacity gains,which may provide nearly balanced links.

b. For second phase capacity gains, the Mobile Receive Diversity would be an excellent choice if performedin conjunction with 4-way receive diversity in the BTS.

Note:The final report will not contain any vendor names but only their generic algo will be discussed.

Note:This document is by far not comprehensive in its subject matter nor provides all possible solutions tothe capacity optimization issue for 3G. The author would appreciate if the reviewer, based on theirexperience, can recommend more solutions to tackle specific resource maximization. Pointing any slip-ups inthe context will also help make this document error free, so that it can be submitted for publication by CDG.Note:This paper is just a quick outline. The Final paper will discuss these points as well as any new points(that might come up from reviewers) in more detail. Plus it will also include other areas such as 10 StepCapacity Management Plan for CDMA, Capacity Checkers that needs to be provider by the Gear maker (forproper resource analysis), Key Capacity Indicators with mathematical derivations etc.

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3CO(Supersizing CDMA) v1.2