Johnny Dixon - BT and 5GHz Topic Lead 5GHz Band UK Spectrum Policy Forum, Cluster 1 event https://www.techuk.org/about/uk-spectrum-policy-forum

1. 5 GHz Band
Johnny Dixon
BT Group Strategy

2. © British Telecommunications plc
Agenda
• Bands currently identified for RLANs
• Potential new bands for RLANs
• European Work on 5 GHz bands
• SPF Document (Janette Stewart)
• Discussion
• Wrap up

3. © British Telecommunications plc
Bands currently identified for RLANs (i)
• 5150 – 5350 MHz
– Limited to indoor operation, 200mW EIRP, DFS (in 5250 – 5350
MHz) and TPC
• 5470 – 5725 MHz
– Limited to 1W EIRP, DFS and TPC

4. © British Telecommunications plc
Bands currently identified for RLANs (ii)
• Image from Ofcom Consultation Document

5. © British Telecommunications plc
Bands currently identified for RLANs (iii)
• International agreement at the ITU WRC-03 (in 2003),
operating “in accordance with ITU-R Resolution 229”
• ECC Decision (04)08 on the harmonised use of the 5 GHz
frequency bands for the implementation of Wireless
Access Systems including Radio Local Area Networks
(WAS/RLANs)
• Commission Decision 2005/513/EC as amended by
Decision 2007/90/EC on the harmonised use of radio
spectrum in the 5 GHz frequency band (5150 - 5350 MHz
and 5470 - 5725 MHz) for the implementation of wireless
access systems including radio local area networks
(WAS/RLANs)

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Bands currently identified for RLANs (iv)
• ITU-R Resolution 229 references DFS as operating in
accordance with ITU-R Recommendation M.1652, which
sets the radar detection threshold
– “The DFS mechanism should be able to detect interference
signals above a minimum DFS detection threshold of –62 dBm
for devices with a maximum e.i.r.p. of < 200 mW and –64 dBm
for devices with a maximum e.i.r.p. of 200 mW to 1 W
averaged over 1 μs”
• The manner in which RLAN devices should apply the radar
detection threshold is defined in ETSI EN 301 893

7. © British Telecommunications plc
Bands currently identified for RLANs (v)
• Problems / Challenges
– Generally works well at present, but …
– 455 MHz => 19 x 20 MHz channels, or
9 x 40 MHz channels, or
4 x 80 MHz channels
– DFS constrains operation, particularly due to false triggering
(radar detection threshold was set in 2003 and has not been
reviewed since)
– Indoor restriction in lower band (what is “indoors”?)
– Mixed views on power limitation in lower band

8. © British Telecommunications plc
Bands currently identified for RLANs (vi)
• We are all making significantly increased use of the 5 GHz
band
• New BT Home Hubs have had 5 GHz for more than 3 years
• All Sky hotspots, and most of their Wi-Fi traffic is on 5 GHz
• More mobile data traffic over Wi-Fi than over cellular
networks
• Most broadband connections in the home are over Wi-Fi

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Discussion

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Potential new bands for RLANs (i)
• 5350 – 5470 MHz
– Currently used by EESS, Radiolocation/Radionavigation, Space
Research
• 5725 – 5850 MHz
– Currently used by Fixed Satellite, Radiolocation, Amateur, plus
BFWA, SRDs & TTT
• 5850 – 5925 MHz
– Currently used by Fixed, Fixed Satellite, plus SRDs & ITS
• These were originally considered in the wider context of
IMT, for WRC-15

11. © British Telecommunications plc
Potential new bands for RLANs (ii)
• Image from Ofcom Consultation Document

12. © British Telecommunications plc
Potential new bands for RLANs (iii)
• Image from Ofcom Consultation Document

13. © British Telecommunications plc
European Work on 5 GHz bands
– European Commission & CEPT (i)
• “Mandate to CEPT to study and identify harmonised
compatibility and sharing conditions for Wireless Access
Systems including Radio Local Area Networks in the bands
5350 - 5470 MHz and 5725 - 5925 MHz ('WAS/RLAN
extension bands') for the provision of wireless broadband
services” (2 September 2013)
• “The CEPT is hereby mandated to undertake the following
tasks:
– Task 1 – identification of compatibility and sharing scenarios
– Task 2 – Development of compatibility and sharing conditions
– Task 3 – Review of compatibility and sharing conditions after
WRC-15”

14. © British Telecommunications plc
European Work on 5 GHz bands
– European Commission & CEPT (ii)
• The EC Mandate requested 2 Reports from CEPT
• First Report to address Tasks (1) & (2) by March 2015
– Issued as CEPT Report 57
• Second Report to provide assessment of Tasks (1) & (2)
following WRC-15, and results of Task (3), by July 2016
– Work was undertaken by CEPT FM55
– About to be issued as CEPT Report 64
– Also uses results from ECC Report 244 on “Compatibility
studies related to RLANs in 5725-5925 MHz”
• Work for WRC-19 Agenda Item 1.16 will continue in CPG
PT D

15. © British Telecommunications plc
European Work on 5 GHz bands
– ETSI BRAN (i)
• BRAN is developing 3 Technical Reports to identify the
feasibility of operating RLANs in the new bands
• TR 103 317 - Mitigation techniques to enable sharing
between RLANs and EESS in the 5350 - 5470 MHz band.
Considers the use of
– 1. Geo-location databases
– 2. Enhanced Dynamic Frequency Selection
– 3. Dedicated Signal Detectors/Collaborative Detection
– 4. Reduced EIRP in combination with bandwidth restrictions

16. © British Telecommunications plc
European Work on 5 GHz bands
– ETSI BRAN (ii)
• TR 103 318 - Additional mitigation techniques to enable
sharing between RLANs and Radiolocation Systems in the
5350 - 5470 MHz and 5725 - 5850 MHz bands.
Considers the use of
– a) Dedicated Radar Signal Detectors/Collaborative Detection
– b) Enhanced DFS
– c) Reduced EIRP in combination with bandwidth restrictions
• TR 103 319 - Mitigation techniques to enable sharing
between RLANs and Road Tolling and Intelligent Transport
systems in the 5725 - 5925 MHz band

17. © British Telecommunications plc
Discussion
• Existing bands
– Changes to the existing regulations?
• New bands
– Feasibility of RLANs sharing with incumbents?
• Any Recommendations from this group for the SPF?

18. © British Telecommunications plc
SPF Document (Janette Stewart, Analysys)

19. © British Telecommunications plc
Wrap up
• Any messages to carry forward?
• Any Recommendations we want to make?