1. ISCO Proteus™:Optimization of UMTS900 Spectral Efficiency Through Node B Uplink Adaptation 24 February 2011

2. Agenda 2 ISCO: Who we are and what we do. Guard bands, transition zones, and UMTS900 spectral efficiency. Proteus Technical Discussion: The benefits of an adaptive UMTS uplink. Proteus platform, roadmap, and product integration.

4. Enhanced spectrum efficiency

5. Improved site performance metrics

6. Higher and more reliable data throughput

8. We are a privately held American company.

9. We are headquartered in the greater Chicago area.

10. We have demonstrated over 20 years of leadership in the research and development of cutting-edge signal conditioning technology.

11. We have become a trusted supplier to the largest North American wireless operators, and are committed to pursuing international growth.

15. Employs novel adaptive RF DSP techniques to remove the effects of interference

16. Maximizes utilization and performance of available spectrum

19. Filters and duplexers

21. InstallationsISCO’s Wireless Solutions 6

22. ISCO’s Proteus: Is a completely digital, tunable platform incorporating ISCO’s PurePass™ RF digital signal processing algorithms Provides a completely flexible platform for shaping, dynamically adapting, and optimizing the uplink signal prior to demodulation Incorporates three distinct functions: Adaptive Interference Mitigation (AIM): Automatically adapts response to minimize the effects of uplink co-channel interference. Reacts within microseconds to changes in the input signal to remove dynamic interference. User-defined Band Reject (UBR): Allows adjustable bandwidth, high-isolation band reject filters to be set anywhere within the spectrum. Carrier Select Conditioning (CSC): Allows adjustable bandwidth, high-isolation bandpass filters to be set anywhere within the spectrum. Proteus™ Core Features and Benefits

29. GSM/UMTS Band Sharing: Benefits and Challenges Deployment of UMTS in the GSM900 MHz band provides: Additional data capacity vital to supporting relentless traffic growth Most efficient use of capital due to superior RF propagation (~60% less sites needed relative to 2100 MHz, improved indoor QoS) BUT… A mixed channel plan is inevitably a compromise between: Keeping the most GSM channels possible in service Minimizing the mutual interference between and GSM/UMTS.

30. Conventional Techniques for Managing Spectrum Refarming Conventional solutions minimize mutual interference in refarmed spectrum in two ways, via: Guard Bands “sandwich” type GSM/UMTS/GSM frequency planning in refarmed areas, which minimizes adjacent channel interferenceby maintaining wide GSM-to-UMTS guard bands. Transition Zones At geographical boundaries between refarmed areas and GSM only areas, a reserved zone is maintained between the two areas, where in a portion of the spectrum neither GSM nor UMTS is deployed. Propagation loss across the zone is relied on to minimize co-channel interference. Both solutions compromise the spectral efficiency of the network from a kbps/Hz/km2 perspective. (From QCOM 80-W1044-1 Rev A)

31. GSM/UMTS Adjacent Channel Interference: A Closer Look UMTS UE UMTS Node B GSM MS GSM BTS Of the four possible GSM/UMTS adjacent channel interference scenarios in refarmed spectrum… GSM BTS to UMTS UE UMTS Node B to GSM MS GSM MS to UMTS Node B UMTS UE to GSM BTS

32. GSM/UMTS Adjacent Channel Interference: A Closer Look UMTS UE UMTS Node B GSM MS GSM BTS Of the four possible GSM/UMTS adjacent channel interference scenarios in refarmed spectrum… GSM BTS to UMTS UE UMTS Node B to GSM MS GSM MS to UMTS Node B UMTS UE to GSM BTS …GSM MS interference on the UMTS uplink is the capacity bottleneck†, and is hence the determining factor in guard band requirements. †3GPP R4-030869

33. GSM/UMTS Adjacent Channel Interference: A Closer Look UMTS UE UMTS Node B GSM MS GSM BTS Poor spectral efficiency from akbps/Hz/km2 perspective Of the four possible GSM/UMTS adjacent channel interference scenarios in refarmed spectrum… GSM BTS to UMTS UE UMTS Node B to GSM MS GSM MS to UMTS Node B UMTS UE to GSM BTS …GSM MS interference on the UMTS uplink is the capacity bottleneck†, and is hence the determining factor in guard band requirements. †3GPP R4-030869

34. Co-channel Interference and Transition Zones Urban Core Transition Area Blanket UMTS900 area At boundaries between the GSM core and refarmed areas, an isolation zone 20 km wide or more is required to prevent GSM from interfering with UMTS900, if propagation loss alone is relied on to attenuate co-channel GSM transmissions. >20 km (145 dB) isolation zone

35. Co-channel Interference and Transition Zones Urban Core Transition Area Blanket UMTS900 area At boundaries between the GSM core and refarmed areas, an isolation zone 20 km wide or more is required to prevent GSM from interfering with UMTS900, if propagation loss alone is relied on to attenuate co-channel GSM transmissions. Poor spectral efficiency from akbps/Hz/km2 perspective >20 km (145 dB) isolation zone

36. Co-channel Interference and Borders Asynchronous transitions to refarmed spectrum at international borders (due to differences in regulatory status or deployment strategy) lead directly to co-channel interference.

38. Minimize guard bands between GSM and UMTS in refarmed spectrum

39. Reduce isolation zones between GSM core and refarmed areas

40. Minimize GSM capacity loss when refarming spectrum

41. Eliminate UMTS capacity loss due to adjacent channel GSM interference

42. Maximize network spectral efficiencyAdvanced Interference Management With RF DSPs

43. Agenda 19 ISCO: Who we are and what we do. Guard bands, transition zones, and UMTS900 spectral efficiency. Proteus Technical Discussion: The benefits of an adaptive UMTS uplink. Proteus platform, roadmap, and product integration.

44. 1. Example UMTS carrier power spectrum Proteus Co-channel Interference Mitigation Explained

45. 2. A GSM or other source appears co-channel 3. The interferer degrades the C/I ratio 4. The Node B commands the mobiles to increase Tx power to maintain target Eb/N0 Proteus Co-channel Interference Mitigation Explained

46. 5. The Proteus DSP filtering is dynamically applied to co-channel GSM interferer, removing a small amount of signal power (processing gain) and a large amount of interference power… 6. … effectively bringing the UMTS carrier back to the original, interference free power levels Proteus Co-channel Interference Mitigation Explained

47. Proteus Performance Against Co-channel GSM Transmissions Single GSM Timeslot Burst Comparison (Frequency Domain) Unprocessed

48. Proteus Performance Against Co-channel GSM Transmissions Single GSM Timeslot Burst (Frequency Domain) Unprocessed Proteus †One UMTS carrier, 3.84 MHz monitor BW, 3 notches enabled, 210 μs group delay, bandwidth factor 1

49. Proteus Performance Against Co-channel GSM Transmissions Single GSM Timeslot Burst Comparison (Time Domain) Unprocessed Proteus Optimized filter bandwidth provides high attenuation of GSM signals. Tunable group delay assures that the attenuation is present instantly.

50. Multi-TRX Performance Case 1: Three simultaneous bursts at 600 kHz spacing Unprocessed Proteus †One UMTS carrier, 3.84 MHz monitor BW, 3 notches enabled, 210 μs group delay, bandwidth factor 1

51. Multi-TRX Performance Case 2: Three sequential bursts at 600 kHz spacing Unprocessed Proteus †One UMTS carrier, 3.84 MHz monitor BW, 3 notches enabled, 210 μs group delay, bandwidth factor 1

52. Multi-TRX Performance Case 2: Three sequential bursts at 600 kHz spacing Unprocessed Proteus †One UMTS carrier, 3.84 MHz monitor BW, 3 notches enabled, 210 μs group delay, bandwidth factor 1

53. Isolation Zone Management Benefits Proteus Conventional Isolation Zone †Maximum GSM uplink co-channel power at Node B constrained to -105 dBm maximum. Proteus: one UMTS carrier, 3.84 MHz monitor BW, 3 notches enabled, 210 μs group delay, bandwidth factor 1, Propagation Model: Hata-COST Rural, GSM MS Tx PWR 33 dBm, 15 dB antenna gain, 20 m antenna height, 7.5 dB body loss, 3 dB feed loss.

54. Isolation Zone Management Benefits Proteus-equipped Node Bs tolerate reductions in isolation zone widths of up to 75% relative to relying on propagation loss alone Proteus Conventional Isolation Zone †Maximum GSM uplink co-channel power at Node B constrained to -105 dBm maximum. Proteus: one UMTS carrier, 3.84 MHz monitor BW, 3 notches enabled, 210 μs group delay, bandwidth factor 1, Propagation Model: Hata-COST Rural, GSM MS Tx PWR 33 dBm, 15 dB antenna gain, 20 m antenna height, 7.5 dB body loss, 3 dB feed loss.

55. Proteus: Spectral Efficiency Improvements Summarized

56. Agenda 32 ISCO: Who we are and what we do. Guard bands, transition zones, and UMTS900 spectral efficiency. Proteus Technical Discussion: The benefits of an adaptive UMTS uplink. Proteus platform, roadmap, and product integration.

58. Digital Signal Processing

60. Local – LCD touchscreen

62. DHCP or static IP

63. Dry contact alarms

65. User-Defined Band-Reject

67. Proteus Configuration Interface Provisioning of all signal processing functions (AIM, UBR, CSC) is done through a simple web interface. Unit can interface via Ethernet to a remote operations location for provisioning, monitoring, alarming, etc.

68. Proteus Configuration Interface UBR filter bandwidth can be set to virtually any desired value by simply setting a parameter in the provisioning UI.

69. Product Roadmap 2011 New Proteus frequency bands (ongoing) 700, 900, 2100, 1700 Proteus One (Q3) Outdoor enclosure, NEMA compliant Single sector, 2-paths 3GPP Compliant Compact (~15 liter) package Simple, MHA-style integration with RRHs Proteus 4G for LTE (Q3) Rx and Tx versions Optimize the forward link in-band group delay PurePass RF Digital Signal Processing for the receive path Pass only desired carriers Create user defined band rejection Mitigate narrow band uplink co-channel interference

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