Presentation on theme: "Key Technical Provisions of the White Paper and Protections Afforded to ITFS Licensees. National ITFS Association Annual Conference February 16 th – 19."— Presentation transcript:
Key Technical Provisions of the White Paper and Protections Afforded to ITFS Licensees. National ITFS Association Annual Conference February 16 th – 19 th, 2004 Fort Lauderdale FL Harry Perlow
2 Table of Contents The Mid Band Segment Interference Mitigation Downconverters NTSC Video and Guard Bands Frequencies and Interference Spectral Masks Rule Changes in the MBS Part 74.x Conclusions
3 Interference Mitigation - MBS What are the issues? Brute Force Overload (BFO). From Cellular Operations to ITFS Receive Sites. Out of Band Emissions (OOBE). From Cellular Operations to ITFS Receive Sites. Flexible Use 2500 25662620 High Power Operations 25722614 Flexible Use 2686 I Band
4 Interference Mitigation - MBS Brute Force Overload ITFS Receive Sites in proximity to Cellular Base Stations must not be allowed to receive high amplitude signals from the LBS and UBS. Unable to predict the locations of future receive sites. Can design around existing ITFS receive sites. High Power Operations 42 MHz GUARDGUARD A4 B4 C4 D4 E4 F4G4 GUARDGUARD Flexible Use I Band
5 Interference Mitigation - MBS MBS Downconverters Filters are built-in. Attenuate signals from the LBS and UBS. Guard Bands are sufficient to allow filters to be effective. Higher Output Capability – IP3. Prevents Brute Force Overload !!! High Power Operations 42 MHz GUARDGUARD A4 B4 C4 D4 E4 F4G4 GUARDGUARD Flexible Use I Band
6 Interference Mitigation - MBS NTSC Video Power Spectral Density varies across bandwidth and decreases rapidly away from Video Carrier. Interference becomes increasingly perceptible. Undesired signals can “mix” in TV tuner. Color Sound 3.58 MHz 4.5 MHz Video 1.25 MHz
7 Interference Mitigation - MBS NTSC Video Power Spectral Density varies across bandwidth and decreases rapidly away from Video Carrier. Interference becomes increasingly perceptible. Undesired signals can “mix” in TV tuner. Color Sound 3.58 MHz 4.5 MHz Video 1.25 MHz
8 Interference Mitigation - MBS Guard Bands Provide for 6 MHz separation in the MBS. Signals that are not NTSC, are high in amplitude and less than 6 MHz away from an NTSC Analog Video signal will cause destructive interference. High Power Operations 42 MHz GUARDGUARD A4 B4 C4 D4 E4 F4G4 GUARDGUARD
9 Interference Mitigation - MBS Frequencies and Co Channel Interference NTSC Analog Video signals – Unequal spectral density and peak power at visual carrier. All NTSC Visual Carrier Frequencies must be the same in every market !!! MBS must be the same size everywhere !!! A4B4C4D4E4F4G4
10 Interference Mitigation - MBS Spectral Masks Out of Band Emissions from the LBS and UBS are In-band or co-channel to the MBS. The Downconverter cannot do a thing about it. OOBE from Base Stations in the LBS and UBS will protect the MBS Noise Floor. A4B4 C4 J Lower Band Segment J
11 Interference Mitigation - MBS Spectral Masks Handsets and CPE OOBE must also protect the MBS. 67 + 10 Log (p) = -37 dBm Free space loss for 100 feet at 2600 MHz = - 70.44 dB The total = -107.44 dBm which 6 dB + below the noise floor. A4B4 C4 J Lower Band Segment 43 + 10 Log (p) At Block Edge 55 + 10 Log (p) 5.5 MHz Away 67 + 10 Log (p) In any MBS Channel
12 Interference Mitigation - MBS A word about Spectral Masks…. X +10 Log (P) Masks are an absolute value. An absolute value represents an absolute distance at an absolute frequency. Interference prediction is then absolute !!! A4B4 C4 J Lower Band Segment 43 + 10 Log (p) At Block Edge 55 + 10 Log (p) 5.5 MHz Away 67 + 10 Log (p) In any MBS Channel
Proposed Technical Rule Changes in the MBS Streamlining Part 74.x
14 Streamlining Part 74.x For analog transmissions, 45 dB co-channel D/U ratio should be maintained. For digital transmissions, 32 dB D/U ratio should be allowed. Based on 26 dB requirement for 64 QAM. Relaxed co-channel D/U ratio for precise frequency offset analog operations at 38 dB. If utilized transmitters must have + or - 10,010 precision frequency offset with + or - 3 Hz stability. If PSAs Overlap, the “football” formed is split. Interference calculations will only be done at points within a PSA/GSA that receive a desired signal level of -80 dBm or greater in a 6 MHz bandwidth or equivalent.
15 Streamlining Part 74.x The undesired signal must be above –106.2 dBm to be considered interference in a 6 MHz bandwidth or equivalent. Adopt a “ di minimis ” interference exception of no more than 0.5 % of the GSA area. Border protection of -73 dBW/m2 at the Grandfathered MBS PSA boundary. §74.903 (2) Adjacent Channel of –10 dB has been proposed. Desired signal is calculated using 4/3 earth curvature terrain – sensitive propagation model. Cross Polarization –26 dB rather than – 20dB.
16 Streamlining Part 74.x MBS OOBE – Unchanged but filters may be upgraded by the LBS and UBS operators. No more than 100 nanoseconds delay – analog. No more than 20 nanoseconds delay – digital. Equipment upgrades – Continued allowance for antenna upgrades subject to zoning, structural and environmental restrictions. Upstream operations in the MBS channels must have written consent from all other licensees in the 2.5 to 2.7 GHz band within 150 miles. Licensees who operate in the MBS in a upstream manner must accept interference from those downstream operations in the MBS.
17 Conclusions High Power, High Site systems can co- exist with Low Site Cellular Architecture with: The Coalition’s Band Plan; Properly Engineered MBS Downconverters; Proposed protection from Out of Band Emissions. Future ITFS Receive Sites are protected. PSA to GSA overlap solution enables “no mans land” to finally be served. Part 74.x of the Rules for the MBS has been streamlined and now makes sense.