Nett incidence of License Fee, Spectrum Charges

Spectrum & 3G services

AUSPI Presentation to TRAI

01.08.06

1st August 2006 AUSPI Proprietary 2

UASL LICENSE & 3GUASL LICENSE & 3G

PRIME ISSUESPRIME ISSUES

INTERFERENCE ISSUESINTERFERENCE ISSUES

SUGGESTIONSSUGGESTIONS


UASL LICENSE & 3GUASL LICENSE & 3G


3G Policy !

• UASL License permits provision of voice and data services and does not distinguish between 2G & 3G.

• Flexibility to provide any service permitted under the license.• 3G is not a new service – no new policy required

• 3G in its simplistic form is nothing but enhanced data application along with multimedia - not a new service. Such services already exist (eg,: EDGE in GSM)

• Since TRAI considering the issue afresh- consider bringing level playing field between operators using different technologies; CDMA & GSM


3G Policy !

• No reservation of spectrum for BSNL/MTNL

• Present technology neutrality only to the extent that DOT does not enforce any technology.

• Establish technology neutrality in real sense and allocate spectrum– let operators use any technology to provide any service permitted under the licence.

• TRAI/DOT should make efforts to get the spectrum in India used for telecom services universally.


PRIME ISSUESPRIME ISSUES


Prime Issues

• What is 3G?

• Band Allocation– 2100 MHz for both CDMA & GSM operators– Appropriateness of 2100 MHz for CDMA operators

• Is 2100 MHz the only band for 3G?– Many options to TRAI for consideration for 3G Services

• Mixed band allocations and interference issues


3G – What is it?

• According to ITU, some key requirements of 3G service include– Improved system capacity– Backward compatibility with 2G systems– Multi media support and– High speed packet data services meeting the following

criteria• 2 mbps in fixed or in building environments

• 384 kbps in pedestrian or urban environments

• 144 kbps in wide area mobile environments

• Variable data base in large geographic area systems (satellite)

Present UASL licence permits all these features/ capabilities


3G – What is ITU saying?

3G is a term coined by global cellular community to indicate the next generation of mobile service capabilities (Higher capacity / Enhanced network Functionalities) that allow advanced services and applications, including multimedia – ITU


3G & ITUSome Key observations

• ITU Defines the capability of 3G and not the association of the same with any particular frequency band

• Ensuring economies of scale by use of global standards and meeting needs of mass market and international roaming

• As per ITU definitions and global best practices, 3G is a service that is agnostic to frequency band of use.

• CDMA2000 and WCDMA both qualify for 3G services and more importantly in any frequency band that they operate in.

• USA is an example for demonstration of operational 3G systems in non-2100MHz band

In the US, 3G services including WCDMA operate in non-2100 MHz bands; they operate in 850/900/1900 MHz band!!!


Is 3G band specific?

• NO• Equating 3G or for that matter WCDMA with 2100 is not appropriate• As defined by ITU and already practiced by some of the countries, 3G

is completely band-agnostic• In the US 3G services including WCDMA operate in 850/1900 MHz

band. • Similarly, incumbent GSM operators in the world in 900 & 1800MHz are

working out deployment options in 900 & 1800MHz! (Telstra is an example)

• Yet another example of WCDMA becoming applicable in 1800MHz is proven by already available commercial equipment availability – Huawei’s announced equipment availability in 1800MHz!

AUSPI would urge TRAI to take cognizance of these developments while arriving at spectrum decisions for WCDMA/3G allocations and NOT limit itself to analysis of 2100MHz


Band Allocation…Inappropriateness of 2100 MHz for CDMA

• Key criteria needed in selecting frequency band for any cellular operation

• Network equipment availability

• Handset availability [Consider dual band with existing freq (800MHz)]

• Global Roaming support

• Economies of scale

• Time to market

• Choice of vendors and wide range in models

The answer is NO

Does 2100 MHz for CDMA meet any of these criteria?


Band Allocation…Inappropriateness of 2100MHz for CDMA

• No vendor is making compatible equipment in 800 and 2100 MHz bands.

• Dual band handsets in 800 and 2100 MHz combination neither AVAILABLE nor do they figure in the manufacturing program of vendors.

• All International CDMA networks are in 800 and 1900 MHz. Global roaming support will be possible in these bands only.

• 2100MHz for CDMA fails on the account of lack of global economies of scale, choice in vendor selection.

• Allocation of 2100MHz for CDMA will put the operators at a disadvantage compared to GSM operators in terms

of appropriate time to market and parity with competition.


Mixed band

• Mixed band allocation between IMT bands B3 & B1

As per ITU Recommendation M.1036-2

– IMT-2000 systems can be deployed in any band- multiple bands have been identified for IMT-2000 systems

– Permit flexibility to administrations to deploy IMT-2000 systems even in bands other than those identified in the RR.

• Solution for India– Mixed band is the only practical solution in India which

ensures growth and evolution of both CDMA and GSM


Issues in Mixed band

• Does it lead to interference -Yes

• Is there a solution - Yes

• Is the solution technically feasible? - Yes

• Is it economically viable? -Yes

So what is the analysis and recommendations?


INTERFERENCE ISSUES


OutlineOutline

Background and RequirementBackground and Requirement

Study on how to mitigate the effect of C2K Base Study on how to mitigate the effect of C2K Base Station Transmit on WCDMA Node-B ReceiveStation Transmit on WCDMA Node-B Receive

Study on how to mitigate the effect of WCDMA Study on how to mitigate the effect of WCDMA Handset (UE) Transmit on C2K Handset ReceiveHandset (UE) Transmit on C2K Handset Receive

Field Trial in India to demonstrate co-existence Field Trial in India to demonstrate co-existence of WCDMA and CDMA in 1900MHz band of WCDMA and CDMA in 1900MHz band


ITU defined Band allocations near 2 GHzITU defined Band allocations near 2 GHz

• ITU band 1, commonly termed the “UMTS” band

– UL:1920- 1980/ DL:2110 -2170 MHz

• ITU band 3, commonly termed the “PCS” band

– UL:1850-1910/ DL:1930 - 1990 MHz

1850 1900 1950 2000 2050 2100 2150 2200

1850 1910 1930 1990 MHz

IMT2000 2100 MHz Band

US PCS 1900 MHz Band

1920 1980 2110 2170 MHz

Mobile TX Base station TX

Mobile TX

Spectrum Overlapping Zone

Base station TX


Possible Spectrum Allocation Plan around 2 GHzPossible Spectrum Allocation Plan around 2 GHz(Mixed Band Plan)(Mixed Band Plan)

• ITU band 1, commonly termed the “UMTS” band

– UL:1920- 1980/ DL:2110 -2170 MHz (60+60 MHz)

• ITU band 3, commonly termed the “PCS” band

– UL:1900-1910/ DL:1980 - 1990 MHz (10+10 MHz)

1850 1900 1950 2000 2050 2100 2150 2200

1900 1910 1980 1990 MHz

IMT2000 2100 MHz Band

US PCS 1900 MHz Band

1920 1980 2110 2170 MHz

Mobile TX

Base Station TX

Base Station TX

Mobile TX

1980 MHz Boundary


Interference Issues in Mixed Band PlanInterference Issues in Mixed Band Plan(at 1980 MHz Boundary)(at 1980 MHz Boundary)

• Major interference issues are:– PCS band (C2K) Base Station Transmit affecting UMTS band (WCDMA) Base

Station (Node B) Receive

– UMTS band (WCDMA) Mobile (UE) Transmit affecting the PCS band (C2K) Mobile (MS)

Receive


Case 1: Case 1:

Study on how to mitigate the effect of C2K Base Station Study on how to mitigate the effect of C2K Base Station

Transmit on WCDMA Node-B ReceiveTransmit on WCDMA Node-B Receive

Definition:Definition:

1. Isolation is the loss between the antenna sockets of the aggressor Tx and the

victim Rx

2. C-C spacing is different from GB, but is related in the following way:

C-C spacing = (A/2+B/2)+GB where A and B are assigned channel bandwidths

of adjacent carriers

3. Channel bandwidth is higher than occupied bandwidth based on the slope of

the stop band skirt

4. Guard band is therefore the edge to edge frequency separation


CDMA BTS to UMTS BTS Interference CDMA BTS to UMTS BTS Interference Analysis ModelAnalysis Model


CDMA BTS to UMTS BTS Interference CDMA BTS to UMTS BTS Interference Analysis PrincipleAnalysis Principle

• Principle I:

The received out-of-band emissions at WCDMA Node B from the CDMA BTS transmitter should be 10dB below the WCDMA Node B receiver noise floor.

• Principle II:

Carrier TX power of CDMA BTS should satisfy WCDMA ACS (Adjacent Channel Selectivity) requirements.

• 3rd order IMP is not a major interference source, specially under enough C-C spacing separation.


C2K BTS Tx Power Amplifier Out put in PCS bandC2K BTS Tx Power Amplifier Out put in PCS band

PA out RF spectrum chart of a

C2K Carrier @ 1981.25 MHz

Duplexer Filter would provide further reduction to this OOBE Spurious emissions

When PA output power is 45.4dBm[=29.40dBm+10×log10(1.250MHz/30kHz)],

Mark1—central of 1X carrier

Mark2—offset of 3.125MHz

Mark3– offset of 4. 375MHz

Mark4-- offset of 5.625MHz

Spurious emission is

-31.85dBm/30kHz, (Mark2)

-38.42dBm/30kHz, (Mark3)

-43.15dBm/30kHz (Mark4) individually.


C2K BTS Tx Duplexer Out put in PCS bandC2K BTS Tx Duplexer Out put in PCS band

Characteristics of a

Duplexer/Filter in C2K BTS

for 1980 to 1990 MHz range

For edge to edge Guard Band of 2.5MHz [=1983.12(Marker 3)-1980.625(Marker 5)],

=-1.7010-(-32.783) =31.082dB attenuation can be achieved by build-in filter in RFE Duplexer. And with additional filter extra attenuation of 30dB Is possible.


Out-of-band emission limits Out-of-band emission limits

in 3gpp2/ITU Spec for 1.9GHz CDMA Transmitterin 3gpp2/ITU Spec for 1.9GHz CDMA Transmitter

Table 4.4.1.3-2. Band Class 1, 4, 6, and 8 Transmitter Spurious Emission Limits of C.S0010-C_v1.0


Isolation requirement for Isolation requirement for Out-Of-Band (OOB) EmissionsOut-Of-Band (OOB) Emissions

• UMTS band of 3.84 MHz Noise Floor = K*T*B+NoiseFigure =10× log10(1.38×10-23×290×3.84×106)+4 = -134.2dBW = -104.2dBm(/3.84MHz)

• Acceptable interference is at least 10 dB below receiver noise floor in the band of

concern (3.84 MHz)

– - 104.2 – 10 = - 114.2 dBm/3.84 MHz

• As per the Out-of-band emission (OOBE) limit by 3GPP2 for PCS, CDMA BTS

transmit OOBE should not exceed - 13 dBm/MHz(-28.23 dBm /30KHz) beyond

1.625 MHz frequency offset from block edge

– For the UMTS band of concern it is - 13 + 10 log (3.84) = -7.2 dBm/3.84 MHz

• Hence, the worst case calculation for the OOBE isolation requirement from ITU

B3 CDMA to ITU B1 WCDMA should be

– - 7.2 - (- 114.2) = 107 dB (Worst Case)

– This isolation requirement =

CDMA BTS Duplexer filter + Additional TX filter + Antenna space isolation


WCDMA Node B Adjacent Channel WCDMA Node B Adjacent Channel Selectivity requirementSelectivity requirement

Wanted signal mean power >-115dBm

Interfering signal mean power < -52dBm


Isolation requirement for WCDMA Isolation requirement for WCDMA

Node B Rx BlockingNode B Rx Blocking • WCDMA Node-B Receiver can tolerate the adjacent channel (out-of-

band) signal level of around - 52 dBm and below.

• The maximum level of the CDMA BTS transmit signal in WCDMA

adjacent channel is 47.8 dBm (combined signal of 3 20W CDMA

carriers)

– 43dBm[20Watt]+10lg(3)=47.8dBm

• Hence, the worst case calculation for isolation requirement for receiver

blocking will be

– 47.8 - (- 52) = 99.8 dB = ~ 100dB

– From this result, it is observed that the Isolation requirement for

Receiver blocking (100 dB) is less than the isolation requirement

for the Out-of-band emissions (107 dB)

– Therefore, if we obtain the required isolation for OOBE that would

be sufficient against receiver blocking for interfering signals at +/- 5

MHz and beyond


Techniques to achieve the required IsolationTechniques to achieve the required Isolation

• Techniques to achieve the required Isolation in order

to combat the Interference effects (both OOBE and

Blocking) – Separation between WCDMA and C2K carriers

– Extra Bandpass filtering in the C2K Base Station transmit path

– Extra Bandpass filtering in the WCDMA Node-B receive path

– Antenna Isolation (between WCDMA and C2K base station

antennas) through physical separation and proper antenna

orientationC-C spacing Separation

Guard Band C2K Base Station transmit filtering

WCDMA Node-B receive filtering

Big (>6.35MHz) 3.8 MHz Low Cost Low cost

Small (3.85MHz) 1.3 MHz High cost High cost


Examples of C-C spacing between the Last WCDMA Examples of C-C spacing between the Last WCDMA

and the first C2K carrierand the first C2K carrier

1980 MHz boundary

2.6 MHz 2. 4 MHz

5 MHz

LastWCDMACarrier

First C2K

Carrier

1982.4 MHz1977.4 MHz

a) With 3.85 MHz C-C SeparationGB=3.85-0.625-1.925=1.3MHz

b) With 5 MHz C-C separation GB=5-0.625-1.925=2.45MHz

1980 MHz boundary

2.6 MHz 1.25 MHz

3.85 MHz

LastWCDMACarrier

First C2K

Carrier

1981.25 MHz1977.4 MHz


How much C-C Sep/Guard Band is really required?How much C-C Sep/Guard Band is really required?

• Required C-C separation can be decreased based on bandpass

filtering– With minimum C-C separation of 3.85 MHz, there is some inherent guard

band(1.3MHz) available between the last WCDMA and the first C2K carrier

– Cost of C2K special BTS TX filters would depend on the roll-off characteristics

– Steeper roll-off requirement would increase cost of the special filters

– Reasonable cost bandpass filters are available in the market that would

provide 60 dB attenuation (from pass band to stop band) within 1.3 MHz from

the edge of the pass band (See next slide for characteristics of such filter)

• As per the Out-of-band emission (OOBE) limit stipulated by 3GPP2 for

the PCS band operations, C2K BTS transmit OOBE would be less than -

13 dBm/MHz beyond 1 MHz of frequency offset

• Any extra guard band beyond 1 MHz would ease design cost on the

special filters in C2K BTS Tx path for OOBE interference reduction


Suitable C2K BTS Tx Bandpass Filter Characteristics Suitable C2K BTS Tx Bandpass Filter Characteristics

(with passband from 1980 to 1990 MHz)(with passband from 1980 to 1990 MHz)

~1.3 Mhz


C-C spacing RecommendationsC-C spacing Recommendations

• Alternative 1: With additional C2K BTS Tx Filter (that would provide

60 dB stop band attenuation) as well as WCDMA Node-B receive

Filter (with 40+ dB stop band rejection):

– Recommended C-C spacing is 3.85 MHz(GB=1.3MHz)

– Here, we get 7 C2K carriers in full 10+10 MHz of PCS band

• Alternative 2: With only C2K BTS Tx Filter and no WCDMA Node-B Rx

Filter

– Recommended C-C spacing is 5 MHz (GB=2.45MHz)

• One way to get is by shifting C2K carriers away from 1980 MHz boundary

– In this case, we get only 6 C2K carriers in PCS band

• Alternative 3: With no additional filters in both C2K BTS transmit and

WCDMA Node-B receive paths

– Recommended C-C spacing is 6.35 MHz (GB=3.8MHz)(with duplexer in

C2K BTS Tx)

– Any more separation beyond 6.35 MHz is not going to be effective

– With this allocation plan, we get only 5 C2K carriers in PCS band


C-C spacing Recommendations FiguresC-C spacing Recommendations Figures

Alternative 1: Additional filter attenuation in CDMA TX and WCDMA RX

Alternative 2: Additional filter attenuation only in CDMA TX path

Alternative 3: No additional filters in CDMA and WCDMA BTS

• WCDMA spectrum will not be effected by present of CDMA;

• In case of co-existence of WCDMA and CDMA operation in 1900MHz band, additional filtering attenuation of 40dB will be needed in the WCDMA RX path.


Antenna deployment strategy Antenna deployment strategy between C2K BTS and WCDMA Node Bbetween C2K BTS and WCDMA Node B

• Alternative1: With filters on both C2K and WCDMA BTSs

– If sharing the same antenna tower and site

• Vertical separation of > 1 m would give 50 dB of suppression

– Different antennas on the same site (Near Field)

• Horizontal separation of >12 m would give 50 dBm of

suppression (Gtx+Grx=10dB )

• H-V separation based on the formula shown in the next slide

• Alternative 2: With C2K Tx filter but no WCDMA Rx filter

– It is the same as the first case

• Alternative 3: With no filters in both C2K and WCDMA BTSs

– Around 800 m to 1 km of site separation (is not practical)

• Possibility of certification from all the major Infrastructure vendors that

they can include this filtering in the C2K base stations is required


Formulae to calculate the Antenna Formulae to calculate the Antenna Isolation availabilityIsolation availability


Isolation ExampleIsolation Example

0. 00

10. 00

20. 00

30. 00

40. 00

50. 00

60. 00

70. 00

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

h- i sol ati on Gtx+Grx=0(dB) h- i sol ati on Gtx+Grx=10(dB) h- i sol ati on Gtx+Grx=30(dB)

Gtx+Grx=30dB is nearly face to face installation.

v- i sol ati on(dB)

20. 00

30. 00

40. 00

50. 00

60. 00

70. 00

80. 00

90. 00

100. 00

110. 00

1 2 3 4 5 6 7 8 9 10

(meter)

Horizontal Isolation

Vertical Isolation

meter


Free Space Transmission Loss vs Distance (Assumes Isotropic Antennas)

-140

-130

-120

-110

-100

-90

-80

-70

-60

-50

0.01 0.10 1.00

Distance (Km)

Loss

(dB

)

1980 MHz 15.0 Meter BTS 15.0 Meter

Free Space path loss model for the PCS bandFree Space path loss model for the PCS band


C2K BTS to WCDMA Node-B Interference: SummaryC2K BTS to WCDMA Node-B Interference: Summary

• Up to 107 dB of isolation is required to mitigate interference due to CDMA

BTS TX affecting WCDMA Node-B RX, for both OOB emission and blocking

• In normal practice, around ~50 dB of antenna isolation is quite easy to get

with good installation practices, for both co-located and non co-located

cases

• With filters in both C2K and WCDMA BTSs, a min C-C frequency of 3.85 MHz

(GB=1.3MHz) is required to take care of the interference issues

– Band pass filter with 60 dB out-of-band rejection/attenuation in CDMA BTS

transmit path is realizable with 3.85 MHz of C-C separation

– Cost of band pass filters would go down with 5 MHz of C-C separation

• With filters in only C2K BTS Tx path, a min C-C separation of 5 MHz

(GB=2.45MHz) is required to take of the effect of IM products

• With no filters in both C2K and WCDMA BTSs, a min C-C separation of 6.35

MHz (GB=3.8MHz) and a site to site separation of around 800 meters is

required


Comparison Table for the 3 AlternativesComparison Table for the 3 Alternatives

Working C-C Separation >/=

Guard Band

Antenna separation requirement

Alternative 1: Filters in both BTSs

3.85 MHz 1.3MHz Practical antenna separation: for 50dB isolation >1m Vertical sep or >12m Horizontal sep for same site

Alternative 2: Filter in C2K BTS only

5 MHz 2.45MHz Practical antenna separation: for 50dB isolation >1m Vertical sep or >12m Horizontal sep for same site

Alternative 3: No filters in both BTSs

6.35 MHz 3.8MHz Unrealistic antenna / site separation


Case 2: Case 2:

Study on how to mitigate the effect of Study on how to mitigate the effect of

WCDMA Handset (UE) Transmit on C2K WCDMA Handset (UE) Transmit on C2K

Handset ReceiveHandset Receive


Some important observations with mobile behaviorSome important observations with mobile behavior

• Handset distribution and usage is highly stochastic in nature

– WCDMA UE and C2K MS both must be active for

interference to occur

– If WCDMA UE spurious emissions are better than standards

specified values, then the interference effect would also be

less

• In general, the maximum Tx power of a class 3 WCDMA UE is

around 10 dBm (which is 11 dB below its assigned peak power

of 21 dBm)

• Finally, it leads to the conclusion that UE to MS interference is

expected to occur in a relatively small percentage of the time


WCDMA UE Emission MaskWCDMA UE Emission Mask

• Minimum Spectrum mask Emission Requirement:

– For frequency offset from 2.5 MHz to 3.5 MHz, - 20 – 15(Δf – 2.5) dBc / 1 MHz



– For frequency offset from 8.5 MHz to 12.5 MHz, - 49 dBc / 1 MHz

- 10 - 8 - 6 - 4 - 2 0 2 4 6 8 10

Frequency Offset in MHz

Re

lati

ve

Ca

rrie

r L

ev

el

in d

Bc 0

- 10

- 50

- 20

- 30

- 40

3.85MHz offset, - 35.4 dBc/1 MHz5MHz offset, - 36.5 dBc/1 MHz


Isolation requirement for C2K Mobile RF BlockingIsolation requirement for C2K Mobile RF Blocking

• As per the OOBE specifications, at 3.85 MHz away from center frequency, WCDMA

OOBE would be - 35.4 dBc/1 MHz

– At 5 MHz frequency offset, WCDMA OOBE would be – 36.5 dBc/1 MHz

• The peak power of WCDMA UE is 21 dBm (for a class 3 device) @ 3.84 MHz, i.e., 15

dBm/1 MHz

• From the emission specifications we can derive:

– At 3.85 MHz frequency offset, WCDMA OOBE is -35.4 - (-15) = - 20.4 dBm/1 MHz

– At 5 MHz frequency offset, WCDMA OOBE is -36.5 - (-15) = - 21.5 dBm/1 MHz

• C2K Handset Adjacent Channel Selectivity (ACS) is - 68 dBm/ 1 MHz

– Amount of isolation required to take care of the de-sensitization of C2K Mobile

from the WCDMA UE TX signal is - 20.4 - (- 68) = 47.6 dB

• As per the 2 slope path loss model, we can get this 47.6 dB of path loss within less than

1 meter distance from the mobile transmitter antenna

– Hence, from RF blocking point of view, there is no interference problem from

WCDMA UE transmit signal to C2K MS receive


Isolation requirement for C2K Mobile Isolation requirement for C2K Mobile Out-of-band EmissionsOut-of-band Emissions

• From the emission specifications, at 3.85 MHz frequency offset, WCDMA OOBE

comes to - 20.4 dBm/1 MHz

• C2K Handset receive filter rejection specification for 3.85 MHz offset from its desired

signal would be around 37 dB

– WCDMA OOBE signal received by C2K mobile @ 3.85 MHz offset is (-20.4 - 37)

= - 57.4 dBm/1 MHz and @ 5 MHz offset it is - 58.5 dBm/1 MHz

• Acceptable interference at C2K mobile is - 116 dBm/1 MHz (10 dB below receiver

noise floor of -106 dBm /1 MHz)

– Amount of isolation required to take care of the OOBE for C2K Mobile from the

WCDMA UE TX signal is - 57.4 - (-116) = 58.6 dB

– Amount of isolation required to take care of the OOBE for C2K Mobile with 5

MHz frequency offset is - 58.5 - (- 116) = 57.5 dB

• As per the 2 slope path loss model, we can get this 58.6 dB of path loss with ~10 m

from the mobile transmitter antenna

– Hence, from OOBE point of view also, there is no interference problem from

WCDMA UE transmit signal to C2K MS receive if 10 m separation is maintained


WCDMA Handset Tx affecting CDMA Handset Rx:WCDMA Handset Tx affecting CDMA Handset Rx:SummarySummary

• From the RF blocking of the C2K MS receive by the WCDMA UE

transmit signal point of view

– with 3.85 or 5 MHz C-C frequency spacing of carriers, around 1 m

mobile separation is required

• From OOBE interference on the C2K MS receive by the WCDMA UE

transmit signal point of view

– with 3.85 or 5 MHz C-C frequency spacing of carriers, 10 m

separation is required

– Under 3.85 C-C frequency spacing, with <10 m , there will be C2K

Forward Link capacity degradation

• Hence, with < 10 m mobile separation and 5 MHz C-C frequency spacing

of carriers, there will be very negligible C2K DL capacity degradation


Field Trial in India to demonstrate co-existence of Field Trial in India to demonstrate co-existence of WCDMA and CDMA WCDMA and CDMA

CDMA frequency for testing : UL:1900-1910 MHz / DL:1980 - 1990 MHz (10+10 MHz)

WCDMA frequency for testing: UL:1920- 1980 MHz / DL:2110 -2170 MHz (60+60 MHz)

Guard Band between CDMA and WCDMA(edge to edge): 2.5MHz,3.75MHz,5MHz(Based on

test cases)

Distance between WCDMA and CDMA 2000 sites is 200m / 500m /1km based on test cases

Filtering attenuation in CDMA Tx and WCDMA Rx paths

CDMA Tx path: 60dB

WCDMA Rx path: 40dB

Antenna space isolation between CDMA and WCDMA BTSs: 50-60dB


Deliverable after Field Trial Test ResultDeliverable after Field Trial Test Result

Policy framework for deployment of 3G services using WCDMA/CDMA

technology in 1900MHz band.

Mitigation of capacity loss / Quality degradation of WCDMA/CDMA

network due to cross technology interference.

Guard band requirement between CDMA and WCDMA for co-

existence 1900MHz band.

Additional filter attenuation requirement in CDMA TX path and

WCDMA RX path for co-existence.

Antenna isolation requirement between CDMA and WCDMA BTS.


ConclusionConclusion

WCDMA(1920-1980 MHz for Node B reception) and CDMA(UL:1900-

1910MHz/DL:1980-1990 MHz) CAN co-exist in India under the following

easy-to-achieve conditions: An edge-to-edge Guard Band of min 1.3MHz using suitable filter in

the CDMA Tx path and WCDMA Rx path.

60dB antenna isolation between CDMA and WCDMA BTS.

10 meters separation between WCDMA and CDMA mobile or 10% DL

CDMA capacity degradation with 3.85MHz(GB=1.3 MHz) C-C

separation.


SUGGESTIONS


(1) Allocate additional 800 MHz (5 MHz from 889-894)

(2) Allocate 1900 MHz for existing expansion as well as 3G services

(3) Allocate appropriate spectrum and Allow flexibility to operators to provide any

service suitable to their requirements and as per the licence


(1) Additional spectrum in 800 MHz


Increase it from 20+20mhz

to 25+25mhz

Reconsider allocation to BSNL /MTNL

Two ways to increase spectrum in 800MHz

How to get Additional Spectrum in 800 MHz Band


Present Allocation in 800 MHz

Present Allocation in 800MHz

International India

824-849MHz / 869-894MHz(25+25 MHz)

824-844MHz / 869-889MHz(20+20 MHz)


Increase 800 MHz bandwidth from 20+20 MHz to 25+25 MHz– How to achieve?

• In India: 844-849 (5MHz)not allocated- wasted

• Why : corresponding downlink portion (889-894MHz) is earmarked for GSM.

• Path forward: shift GSM from this portion to DCS 1800 MHz band


Issues in shifting GSM to DCS 1800 MHz band

Arguments For : • CDMA operators have no other option- GSM operators have the

option to go to 1800MHz band• Known and established Compatibility between 900 and 1800 MHz• More than enough spectrum is available in 1800MHz band• Even presently this portion of 900 MHz band (889-894) is not

available to GSM operators at many places• TRAI recommended this portion to be vacated from existing users

and be allocated to the 4th cellular operators who have frequency in 1800 MHz band only which is against the license conditions of 4th Cellular operators [TRAI Reco of 13th May 2005 on Spectrum Related Issues para 3.5.4 at pages 69 & 70]

Arguments Against : • No argument


Reconsider allocation to BSNL/MTNL

• No reservation for BSNL/MTNL for the future.

• In GSM no. of subscribers of MTNL as on 30.6.06 is 2.17 Million and for CDMA about 1.5 lakh (Delhi + Mumbai).

• They have 4 CDMA carriers (5+5Mhz) in Delhi and Mumbai for less than 2 lakhs subscribers!

• Similarly in case of BSNL the GSM subscribers are 18.3 Million (all India) and for CDMA the number is about 2.6 Million (all India)

• Both BSNL&MTNL are concentrating on GSM and blocking spectrum for CDMA

• Both are not even entitled for 4 CDMA carriers since they are also using cor-DECT and according to the licence conditions those using cor-DECT are entitled for only 3 carriers in CDMA band.


(2)– Allocate 1900 MHz for expansion of existing

network as well as for 3G services

– Consider the utilisation of cor-DECT frequencies in India - occupies crucial portion of 1900 MHz PCS band {1880-1900MHz}

– In metro and large urban areas wherever cor-DECT is not used.

– This spectrum is wasted– Reconsideration required.


Suggested Spectrum Allocation

1900 MHz Band 1900 MHz Band

CDMA 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0

PCS 1900

1880 - 1910 / 1960 - 1990 1880 - 1910 1960 - 1990

800 MHz Band

CDMA 1 2 3 4 5 6 7 8 9 0

800824 - 849 / 869 -

894 824 - 849 869 - 894

*Wherever Cor-DECT frequency is not allocated


(3)– Allocate appropriate spectrum and allow flexibility

to operators top provide any service suitable to their requirements

– Licence is :• Technology neutral• Permits voice and data services • Permts all services which dio not require a separate licence.

– Within the allocated spectrum allow operators to use all evolving technologies.


• 2300-2400 MHz, 2500-2690 MHz, 3300-3800MHz and for Wi-MAX applications.

• Not to consider 700 MHz for Wi-MAX application.• Minimum assignment of 21 MHz contiguous band.• Make available sufficient spectrum for Wi-MAX & priority

allocation be given to existing UASLs on circle basis.• Pricing mechanism for Wi-MAX should be:

– Levy of revenue share as is done for access providers.– Amount should be <1% to cover the administrative cost.

Spectrum for Wi-MAX


Thank you!

Contact us at: [email protected]

Date post:	18-Jun-2015
Category:	Technology
Upload:	dominque23
View:	761 times
Download:	2 times