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Spectrum & 3G services

Spectrum & 3G services. AUSPI Presentation to TRAI 01.08.06. UASL LICENSE & 3G. PRIME ISSUES. INTERFERENCE ISSUES. SUGGESTIONS. UASL LICENSE & 3G. 3G Policy !. UASL License permits provision of voice and data services and does not distinguish between 2G & 3G.

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Spectrum & 3G services

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  1. Spectrum & 3G services AUSPI Presentation to TRAI 01.08.06

  2. UASL LICENSE & 3G PRIME ISSUES INTERFERENCE ISSUES SUGGESTIONS AUSPI Proprietary

  3. UASL LICENSE & 3G AUSPI Proprietary

  4. 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 AUSPI Proprietary

  5. 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. AUSPI Proprietary

  6. PRIME ISSUES AUSPI Proprietary

  7. 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 AUSPI Proprietary

  8. 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 AUSPI Proprietary

  9. 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 AUSPI Proprietary

  10. 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!!! AUSPI Proprietary

  11. 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 AUSPI Proprietary

  12. 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 Does 2100 MHz for CDMA meet any of these criteria? The answer is NO AUSPI Proprietary

  13. 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. AUSPI Proprietary

  14. Mixed band • Mixed band allocation betweenIMT 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 AUSPI Proprietary

  15. 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? AUSPI Proprietary

  16. INTERFERENCE ISSUES AUSPI Proprietary

  17. Outline • Background and Requirement • Study on how to mitigate the effect of C2K Base Station Transmit on WCDMA Node-B Receive • Study on how to mitigate the effect of WCDMA Handset (UE) Transmit on C2K Handset Receive • Field Trial in India to demonstrate co-existence of WCDMA and CDMA in 1900MHz band AUSPI Proprietary

  18. US PCS 1900 MHz Band Spectrum Overlapping Zone 1850 1910 1930 1990 MHz Base station TX Mobile TX Base station TX Mobile TX IMT2000 2100 MHz Band 1920 1980 2110 2170 MHz 1850 1900 1950 2000 2050 2100 2150 2200 ITU 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 AUSPI Proprietary

  19. US PCS 1900 MHz Band 1900 1910 1980 1990 MHz Base Station TX Mobile TX Base Station TX Mobile TX IMT2000 2100 MHz Band 1920 1980 2110 2170 MHz 1850 1900 1950 2000 2050 2100 2150 2200 1980 MHz Boundary Possible Spectrum Allocation Plan around 2 GHz(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) AUSPI Proprietary

  20. Interference Issues in Mixed Band Plan(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 AUSPI Proprietary

  21. Case 1: Study on how to mitigate the effect of C2K Base Station Transmit on WCDMA Node-B Receive 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 AUSPI Proprietary

  22. CDMA BTS to UMTS BTS Interference Analysis Model AUSPI Proprietary

  23. CDMA BTS to UMTS BTS Interference Analysis 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. AUSPI Proprietary

  24. C2K BTS Tx Power Amplifier Out put in PCS band PA out RF spectrum chart of a C2K Carrier @ 1981.25 MHz 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. Duplexer Filter would provide further reduction to this OOBE Spurious emissions AUSPI Proprietary

  25. C2K 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. AUSPI Proprietary

  26. Out-of-band emission limits in 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 AUSPI Proprietary

  27. Isolation requirement for Out-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 AUSPI Proprietary

  28. WCDMA Node B Adjacent Channel Selectivity requirement Wanted signal mean power >-115dBm Interfering signal mean power < -52dBm AUSPI Proprietary

  29. Isolation requirement for WCDMA Node 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 AUSPI Proprietary

  30. Techniques 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 orientation AUSPI Proprietary

  31. 2.6 MHz 1.25 MHz First C2K Carrier Last WCDMA Carrier 3.85 MHz 1981.25 MHz 1977.4 MHz 1980 MHz boundary Examples of C-C spacing between the Last WCDMA and the first C2K carrier • With 3.85 MHz C-C Separation • GB=3.85-0.625-1.925=1.3MHz b) With 5 MHz C-C separation GB=5-0.625-1.925=2.45MHz 2.6 MHz 2. 4 MHz First C2K Carrier Last WCDMA Carrier 5 MHz 1977.4 MHz 1982.4 MHz 1980 MHz boundary AUSPI Proprietary

  32. 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 AUSPI Proprietary

  33. ~1.3 Mhz Suitable C2K BTS Tx Bandpass Filter Characteristics (with passband from 1980 to 1990 MHz) AUSPI Proprietary

  34. C-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 AUSPI Proprietary

  35. C-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. AUSPI Proprietary

  36. Antenna deployment strategy between 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 AUSPI Proprietary

  37. Formulae to calculate the Antenna Isolation availability AUSPI Proprietary

  38. Isolation Example Horizontal Isolation Vertical Isolation meter Gtx+Grx=30dB is nearly face to face installation. AUSPI Proprietary

  39. Free Space path loss model for the PCS band AUSPI Proprietary

  40. C2K 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 AUSPI Proprietary

  41. Comparison Table for the 3 Alternatives AUSPI Proprietary

  42. Case 2: Study on how to mitigate the effect of WCDMA Handset (UE) Transmit on C2K Handset Receive AUSPI Proprietary

  43. Some 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 AUSPI Proprietary

  44. 0 - 10 - 20 Relative Carrier Level in dBc - 30 - 40 - 50 - 10 - 8 - 6 - 4 - 2 0 2 4 6 8 10 Frequency Offset in MHz WCDMA 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 3.5 MHz to 7.5 MHz, - 35 – 1(Δf – 3.5) dBc / 1 MHz • For frequency offset from 7.5 MHz to 8.5 MHz, - 39 – 10(Δf – 7.5) dBc / 1 MHz • For frequency offset from 8.5 MHz to 12.5 MHz, - 49 dBc / 1 MHz 3.85MHz offset, - 35.4 dBc/1 MHz 5MHz offset, - 36.5 dBc/1 MHz AUSPI Proprietary

  45. Isolation 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 AUSPI Proprietary

  46. Isolation requirement for C2K Mobile Out-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 AUSPI Proprietary

  47. WCDMA Handset Tx affecting CDMA Handset Rx:Summary • 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 AUSPI Proprietary

  48. Field Trial in India to demonstrate co-existence of 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 AUSPI Proprietary

  49. Deliverable 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. AUSPI Proprietary

  50. Conclusion • 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. AUSPI Proprietary

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