White Box Solutions - Response by sdfwerte

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									Some considerations for developing wireless
    (radio) and wireline harmonisation

    Presentation to CENELEC 205a Working
        Group 10 at Rome on 11/10/99
                      by
            Professor Paul A Brown
       Communications Research Centre
           Lancaster University, UK.

                                    PAB/slide 1
  Harmonising wireless (radio) and wireline
                 networks
Introduction

In order to harmonise HF wireless and wireline networks we
need to consider a number of key issues including:
• Spectrum efficiency of wireless and wireline systems
• The physical distribution and location of HF radio links
• The primary function of such links (e.g. broadcast,
   commercial, government, military, civil aviation, maritime,
   amateur etc)
• Proximity factors for wireless and wireline systems (e.g.
   link power budget, antenna factor, service, receiver
   characteristics, radiation efficiency of cables etc)
  N.B. DPL= Digital Power Line System                PAB/slide 2
          HF point to point wireless links…
                      (In 1MHz of spectrum)




                            2400 Baud (Bit/s)

             Node A           x 400             Node B

Assumes, 2.5 kHz channels, no guard bands and uniform distribution
                                                    PAB/slide 3
                  Large scale DPL deployment...
             (Also using the same 1MHz of spectrum)



             Electricity
Electricity & Telecomms
                                                   40,000
      DPL Basestation                            x 50,000
                                                   60,000
                                                    etc...
                               1Mbit/s
                             (multiplexed)

                           A single DPL ‘cell’
                                                  PAB/slide 4
        Wireline enhances spectrum utilisation
• Figure 1 attached illustrates ‘ideal’ HF communications range (shown
  in white, field strength > 30 dBuV/m) for a 1 kW transmitter located at
  Kendal assuming signal propagation via the ionosphere to any
  locations in the UK on a frequency of 6.1 MHz at 1200 UT and for a
  sunspot number of 100.
• If we assume say a I MHz frequency slot (6.1 MHz+/-500 kHz)
  consisting of 400 x 2.5 kHz radio channels (without guard bands)
  running continuously 24 hours per day at 2400 bit/s we have an
  overall maximum HF radio data transmission capability of ~ 10
  Gigabytes per day.
• If we assume 20,000,000 house holds in UK, 200 houses per
  substation and 10% service penetration. Then the instantaneous DPL
  data capacity = 5 Gbit/s. Then over 24 hour period we have ~
  100,000 Gigabytes per day.
• It follows that by cellular re-use of a 1 MHz element of HF
  spectrum a DPL solution is ~ 10,000 times more effective than a
  conventional radio solution, per unit time, per Hz of spectrum.
                                                        PAB/slide 5
              KENDAL [ISOTROPE ] 1kW -1deg 12ut 6.100MHz JUN 100ssn 0.0Q
                                                                                                     DBU
 Transmitter location to grid of Receivers
                                                                                Default/default.I11
      20W             10W                0E               10E                          Version 981015W

                                                                                         ICEPAC
                                                                                          Field Strength
60N                                                                       60N                 Median
                                                                                               [dBu]
                                                                                                     > 35
                                                                                                     > 30
20W
                                                                                                     > 25
                                                                                                     > 20
                                                                                                     > 15
                                                                                                     > 10
                                                                                                     < 10
                                                                                          Min= -15.10
                                                                                          Max= 37.20

                                                                                      USRI coefficients




50N                                                                       50N




                                                                          10E
               10W                        0E
  0     200   400    600    800   1000    1200   1400   1600    1800   2000KM               NTIA/ITS




                            Figure 1                                                            PAB/slide 6
              Developing proximity factors

• In our example we have 400 HF radio channels, without guard bands,
  operating over 1 MHz of continuous spectrum. We now consider the
  issues of the physical distribution of such HF radio links in relation to
  wireline systems.
• Earlier work indicates a 100 to 200m clearance zone required for 20
  dB carriers/noise ratio at each HF link receiver for a 100 Watt link
  transmitter power [1].
• Assuming an ‘average’ distribution of such link sites, i.e. 800 link
  terminals in UK (including Northern Ireland). This gives one link site
  per 303.64 square km [2]. Assuming a protection zone of radius 200
  m around each HF terminal site leaves 242,809 square km [3] for
  cellular powerline deployment.
• We now require to develop more realistic criteria for the number of HF
  link terminals, their relative distributions and the potential number and
  relative distribution of powerline systems per unit area.
                                                                 PAB/slide 7
                        Summary
• We have illustrated, albeit simplistically, that with a 100%
  utilisation of a given frequency slot (1 MHz) by
  conventional HF wireless (radio) communications it is
  possible to further enhance the utilisation of the same
  element of HF spectrum within 99.96% of the same
  geographic area by a factor of 10,000 whilst maintaining
  coexistence between the wireless and wireline solutions.
  More detailed co-existence algorithms now require to be
  developed

• Efficient spectrum management should enable wireless
  and wireline communications to develop and coexist for
  the benefit of all.
                                                PAB/slide 8
          References and calculations
References
[1] Paul Brown, ‘Near field/far field radiated emission
benchmarking’, German Regulatory Working Group, 25th
January 1999
[2] UK Government Statistical Service
(www.statistics.gov.uk)
Calculations
UK land area = 242,910 sq km; therefore we have 303.64 sq
km for each of 800 HF link terminals. Total protection zone
(area) for 800 HF link terminals = 100.53 sq km. Therefore
we have 242809 sq km for powerline deployment.
                                                      PAB/slide 9
Presentation to CENELEC SC205a WG 10

     Brussels, 16th November 1999

 Near field/far field radiated emission
            benchmarking
                 by
       Professor Paul A Brown
     CRC, Lancaster University, UK

                                      Page 1 of 13
                  CRC, Lancaster University, UK
                 On-going research and development

Assessing the near-field effects of high frequency power line signals

                                        210 metres




             Metropolitan / campus area environment

                                                             Page 2 of 13
HF Wide Band Dipole Antenna at Lancaster University
     Communications Research Centre (CRC)




         FWB/2530 from SMC Communications
                                                      Page 3 of 13
           FWB/2530 Wideband HF antenna from SMC
               Communications - Specification
     3.5



     3.0


     2.5



     2.0



     1.5



     1.0
           2.8   4.8   6.8   8.8   10.8   12.8   14.8   16.8   18.8   20.8   22.8   24.8   26.8   28.8




Freq. Range            : 2.5 - 30 MHz
Power Rating           : 1 kW Ave
Max VSWR               : 2.5:1
Gain                   : Up to 3 dBi                                       Page 4 of 13
Input Impedance        : 50 Ohms unbalanced
Construction           : Heavy duty cadmium copper, with galvanised steel and
                         stainless steel fittings
FWB/2530 Wideband HF antenna from SMC
  Communications - Radiating Patterns




                                        Page 5 of 13
HF signal injection equipment configuration

                  50 Coaxial
                   Connector                          13A
                                                     Sockets



                                                HF Coupling Unit
                                                 (With 13A by-
                                                  pass socket)


                                    IEC Mains
              +20 dBm
                                      Lead

                                 Signal
     50                        Generator
    Coaxial        Transient
    Cable         Suppresser
                                                                   Page 6 of 13
Free space path loss from Bowland Tower to HF Antenna CRC




                      Resolution bandwidth 300 Hz
                      Video bandwidth 30 Hz



                                                       Page 7 of 13
        Path loss measurements and calculations

• Calculated 210m free space path loss at 5 MHz (wavelength = 60 metres)         = 33 dB


• Calculated 210m free space path loss at 7.082 MHz (wavelength = 42.36m) = 36 dB


• Measured 210m path loss at 5 MHz = (+ 20 dBm - 80 dBm)                        = 100 dB


• Measured radiation efficiency of building internal wiring, with powerline signal
 injected via power socket in line/phase to earth mode = (100 - 33)            = - 67 dB


• Field strength anticipated at antenna for 1 mW signal injected into building wiring
                                                                             = -9dBuV/m
             N.B. No allowance for dipole as opposed to isotropic antenna
                                                                                 Page 8 of 13
            Assessing the far-field effects of high frequency power line signals

E/F Layer




                           333 Kilometers                           333 Kilometers


                 Single Hop                        300 Kilometers
                 Signal Path


D Layer

                                  288 Kilometers



                     Lancaster                                                  Hitchin



                                                                                          Page 9 of 13
Ionospheric properties on 13/10/98 between 14:06 and 14:08




                                                        Page 10 of 13
       Consider effects on nearby HF link receiver
• Consider voice (single side-band SSB) link on 7.082 MHz

• Transmitter power 100 Watts, antennas 2 x dipoles, path
  length direct = 288 km (Lancaster to Hitchin), height of
  reflective (E/F) layer = 300 km, received signal levels (S 9 + 10
  to 15dB) = - 70 dBm

• Calculated HF link receive power level at (50 ohm) receiver
  antenna port = - 56 dBm

• Difference between measured and calculated values (14 dB)
  possibly due to ionospheric attenuation (D layer),
  measurement inaccuracy etc

• Calculated field strength at receiving antennas = 38dBuV/m
                                                            Page 11 of 13
Effect of near field ‘jammer’ on HF link performance

• HF link receiver antenna subject to 38 dBuV/m field
  strength (calculated) from far-end link transmitter (wanted
  signal). Input power level to local link receiver measured at
  - 70 dBm

• Powerline jammer (1 mW) located 210 metres from local
  HF link antenna produces an interfering signal (calculated)
  of -9dBuv/m at the local receiver antenna. Input power to
  receiver measured (extrapolated) at - 100 dBm

• Therefore measured signal to noise at local victim receiver
  (wanted signal + noise to jammer ratio ) = 30 dB

• Calculated difference in field strengths = 47 dB
                                                         Page 12 of 13
                            Conclusions
• Radiation efficiency of mains wiring (in-building injection, line to earth)
  ~ - 67dB reference isotropic source

• Measured signal to noise (jammer) ratio at victim receiver = 30 dB for
  100 watt, HF link, power budget

• A 100 watt, HF, SSB (voice), link has been observed to operate with a
  30 dB S+N/N ratio (measured) in close proximity (210 metres) to a
  powerline jammer

• The link noise floor (local) was measured at -100dBm in a 300 Hz
  resolution bandwidth. If the injected powerline signal power level was
  < 1 mW then it would not be detectable above the noise floor by the
  victim receiver

• The near field, far field and cumulative effects of such deployments
  now require to be further modeled and measured
                                                                      Page 13 of 13

								
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