criteria using OfW49 Alessandra Lees Joint Radio Company Ltd - - PowerPoint PPT Presentation

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk Alessandra Lees Joint Radio Company Ltd Alessandra.Lees@JRC.co.uk Tel: 02077065196 Skype: alexlees_jrc

JRC current assignment criteria using OfW49

ST(17)006 ST(17)006

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

JRC assignments key points

• Generally follow ACP including non-adjacent

cell channels for additional capacity.

• No longer assign inter-leave channels – not

compatible with digital equipment. Some existing systems still use them.

• Cross polar discrimination also used.
• Standard outstations are those with 12element

Yagi

• Non-standard outstations not used in

calculations of systems EIRP or interference.

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

Basic 12 cell repeat pattern Worst case 150km cell centre to cell centre. Worst case 200km interference check

Figure 1 taken from OfW49 document: https://www.ofcom.org.uk/__data/assets/pdf_file/0026/77336/tfac_ofw49.pdf

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

Figure 2 taken from OfW49 document: https://www.ofcom.org.uk/__data/assets/pdf_file/0026/77336/tfac_ofw49.pdf

Maximum path loss assigned = 143dB Total path loss = free space loss + terrain obstruction loss+ clutter loss Clutter loss limited to 20dB, up to 30dB considered on case by case basis.

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

Figure 6 taken from OfW49 document: https://www.ofcom.org.uk/__data/assets/pdf_file/0026/77336/tfac_ofw49.pdf

Maximum end to end circuit loss assigned = 134dB EECL= total path loss + (total scanner losses – scanner gain) + (total

• utstation losses – outstation gain)

Total scanner/outstation losses include: Feeders Other losses: Other miscellaneous loss Connector loss Feeder tail loss Antenna tail loss

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

Assigning path: End to End Circuit Loss (EECL)

Information taken from JRC authorisation document

Minimum EIRP limited to -20dBW Exceeds EECLmax

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

EIRP Receiver input port level = -122dBW (-117dBW duplicated equipment with common antenna) Calculate EIRP: Scanner EIRP = Outstation receiver input port level + Loss to Outstation

• Loss to Outstation = EECL - Sc Feeder Loss – Sc other loss + Sc gain
• If the worst outstation EECL is > EECLmax then use EECLmax

Outstation EIRP = Scanner receiver input port level + Loss to Scanner

• Loss to Scanner = EECL – Os Feeder Loss – Os other loss + Os gain
• If the worst outstation EECL is > EECLmax then use EECLmax

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

2011

Loss to Outstation = EECLmax - Sc Feeder Loss – Sc other loss + Sc gain 123.9dB - 3dB – 1dB + 8.1dB = 128dB Scanner EIRP = Receiver input port level + Loss to Outstation = -122.0dBW + 128dB = 6dBW

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

2011

Maximum transmitter output powers for the assigning path:

(unprotected or protected two aerial working)

Scanner: Tx power (dBm) = outstation wanted signal (-92 dBm) + EECLmax (-30 for dBW) Outstation: Tx power (dBm) = scanner wanted signal + Individual EECL (or EECLmax) A protected single common aerial system has an extra 5dB receive signal level (-87dBm)

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

Figure 3 taken from OfW49 document: https://www.ofcom.org.uk/__data/assets/pdf_file/0026/77336/tfac_ofw49.pdf

Extra 5dB passive splitter for receive path

Joint Radio Company: Making the spectrum and technology work for your business www.JRC.co.uk

Summary of current OfW 49

Assignment Criteria Current OfW 49 Unfaded wanted signal

• 92dBm

Interference + Noise 99.9% ≤ -114 dBm Unfaded W/U 22dB Maximum path loss 143dB Maximum EECL 134dB