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An overview of how dynamic spectrum access enables the latest generation of Wi-Fi (IEEE 802.11af ) to achieve greater coverage and capacity
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(c) Larkhill Consultancy Limited 2014
Dynamic spectrum and the race for mobile capacity
29th October 2014
(c) Larkhill Consultancy Limited 2014
Agenda
• Increasing role for licence exempt spectrum sharing in serving the growing mobile data demand
• Importance of lower frequencies – significance of TV white spaces and dynamic spectrum access
• What the arrival of 802.11af and triple band access points will mean for Wi-Fi
(c) Larkhill Consultancy Limited 2014
Anytime, anywhere on a mobile device …..• Mobile devices are becoming the
dominant means of access to a growing host of online services
• Tablets and smartphones have broadened Internet use
• As services use higher quality images & video, wireless network capacity needs to rise….
• Spectrum is a key input …
(c) Larkhill Consultancy Limited 2014
Capacity is important but there are other factors
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BroadbandInternet of
ThingsCapacity
Coverage
Flexibility
Resilience
Wireless access networksWAN + LAN
(c) Larkhill Consultancy Limited 2014
Spectrum availability is critical to meeting expectations for wireless
• Access to spectrum is key to extracting value from wireless technology
• Harmonised access enables economies of scale in equipment
• Wider bands enable greater performance – affecting the dimensioning of networks
• Lower frequencies enable better coverage
• Future networks need to straddle multiple bands to deliver the best possible connectivity to users wherever they are
Frequency
2GHz 3.5GHz1GHz
GSM
TV+
802.11afRadio
200 MHz 600 THz
GSM
3GLTE
Wi-FI
LTE
2.4 2.62.11.8.9.8.47-.79 GHz
(c) Larkhill Consultancy Limited 2014
Licence exempt access is now a key tool in meeting mobile demand
• Licence exempt networks have taken an increasing share of mobile data traffic
• Licence exemption (LE) is a powerful tool for wireless innovation
• It enables flexible, ad-hoc and device-to-device direct links
• Until now, LE has been confined to short range applications & higher frequencies
• Dynamic spectrum access technology allows higher transmission power according to location & safe sharing with licensed users
Source: TCS-Sensor Lab
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(c) Larkhill Consultancy Limited 2014
Wi-Fi family tree
802.11b11 Mbps , 20 MHz DSSS,
Band : 2.4 GHz
802.11a54 Mbps, 20 MHz OFDM
Band : 5 GHz
802.11g54 Mbps, 20 MHz OFDM
Band : 2.4 GHz
802.11n600 Mbps, 20/40 MHz, OFDM + MIMO
Bands: 2.4 or 5 GHz
802.11af600 Mbps
Band: TVWS
802.11ac1.3 Gbps
Band: 5 GHz
802.11ad6 Gbps
Band: 60 GHZ
WiGig
.47-.79 (UHF)
2.4 GHz
5 GHz 60
Frequency (GHz)
.47-.79 (UHF)
2.4 GHz
5 GHz 60
Frequency (GHz)
.47-.79 (UHF)
2.4 GHz
5 GHz 60
Frequency (GHz)
.47-.79 (UHF)
2.4 GHz
5 GHz 60
Frequency (GHz)
Source: Mediatek, Larkhill analysis
(c) Larkhill Consultancy Limited 2014
5 GHz is good for adding capacity
Band Capacity(MHz)
Status
5150 to 5250 MHz 100 the “new global band”
5250 to 5350 MHz 100 OK in many regulatory domains
5350 to 5470 MHz ? problematic everywhere
5470 to 5725 MHz 255 OK in EU; radars limit its use elsewhere
5725 to 5825 MHz 100 OK in EU, but limited to 25 mW
5825 to 5925 MHz EU plans to share with road tolling
Source: Mediatek, Larkhill analysis
(c) Larkhill Consultancy Limited 2014
60 GHz – massive additional licence-exempt capacity• Opportunity to deploy
large additional Wi-Fi capacity
• Fits well with urban environments where user density is high and fibre access is widely available
• In-room networks
• Point to point links for backhaul (line of sight)
(c) Larkhill Consultancy Limited 2014
Adding more sub-5 GHz capacity depends on more efficient sharing
• Although spectrum is fully allocated,much is left unused – geographicallyand temporally
• Dynamic spectrum access uses newtechnology to enable opportunistic,licence-exempt access
• This provides a great opportunity toboost the coverage and capacity thatWi-Fi networks can enable
• The Dynamic Spectrum Alliance istaking the technology around the world
OK, you can use channels x, y, z
Geolocationdatabase
My device
I’m in Glasgow
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(c) Larkhill Consultancy Limited 2014
Source: BT R&D
Lower frequencies help fill coverage gaps and enhance capacity
Simulation of coverage with 20% access point
penetration, in a 1 km2
dense urban area in Fulham, London
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Wi-Fi , 5 GHz Wi-Fi , 2.4 GHz TV White Spaces – 600 MHz
(c) Larkhill Consultancy Limited 2014
TV white spaces - global opportunity to access lower frequencies
• UHF frequencies have bee allocated for TV broadcasting (470-790 MHz in EU)
• Unused gaps in these bands are called TV white spaces (TVWS)
• New Dynamic spectrum access technology protects TV reception whilst releasing valuable new capacity for licence-exempt use
• Already commercialised in the US, pilot deployments are underway across the rest of the world, as regulators prepare enabling frameworks
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Image source: Ofcom
(c) Larkhill Consultancy Limited 2014
Dynamic Spectrum Access can enable a full range of business models
Facilitates centralised
infrastructure investment
Scope for innovation
Coexistence of multiple
users/applications
Can protect services
against effects of interference
Enables infrastructure
investment by end users
Wi-Fi LTE
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(c) Larkhill Consultancy Limited 2014
IEEE 802.11af adds TV white spaces to the Wi-Fi band family
• First wireless LAN standard using geo-location databases for access to spectrum• IETF PAWS will be the predominant interface
• Adapted from state-of-the-art 802.11ac PHY• 6,7 or 8 MHz TV channels for global applicability
• < 35 Mbit/s per TV channel (8 MHz)
• < 560 Mbps with 4 TV channels bonded and 4 spatial paths
• Enterprise management of database access• Using a Registered Location Secure Server
• Maintains a local copy of local white space map
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8 8
8 8
Total: 16 MHz
8
Total: 8 MHz
8 88 8
Total: 32 MHz
8 88 8
802.11afchannel configurations
(c) Larkhill Consultancy Limited 2014
Three bands improve scalability of Wi-Fi coverage
Kilometres
TV White Spaces
2.4 GHz5 GHz
Tens of metres
10-20 metres
(c) Larkhill Consultancy Limited 2014
Triple-band Wi-Fi set to become the new norm• Adding 802.11 af to standard Wi-Fi
brings TV white spaces coverage and capacity
• New triple band Wi-Fi will help improve coverage and capacity, in urban and rural locations
• First prototypes were tested in the Glasgow White Spaces Pilot in June 2014
(c) Larkhill Consultancy Limited 2014
Summary
• Increasing personal connectivity is driving demand for more capacity and better coverage
• Spectrum clearance is too slow, so dynamic spectrum access (DSA) technology enables faster access to extra capacity
• DSA will revolutionise spectrum access & management
• 3. Initially, enabling the TV white spaces to fill coverage gaps as well as adding valuable capacity, using the new 802.11af standard
• Providing a foundation for other bands to be added over time (3.5 GHz is currently under discussion in the US)
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Source: Microsoft
(c) Larkhill Consultancy Limited 2014
Thank you
• Contact:
About Larkhill
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(c) Larkhill Consultancy Limited 2014
Further reading
• Background material and information about pilots etc. Dynamic Spectrum Alliance
• The Centre for White Space Communications(University of Strathclyde)
• Microsoft dynamic spectrum access pilots
• White spaces applications in Singapore
• Airties: 802.11ac is not sufficient