LTE and WiFi on the LESami Susiaho – Head of Edge Technologies, Sky Business, Sky UK

Cambridge wireless in London 17th September 2015Star Wars: The Empire Strikes Back

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Overall picture of technologies

LTE-U

• Wild west LTE on 5 GHz

• In the US, China, India and Korea

• Ready, but requires hardware update

LAA-LTE

• Potentially polite LTE on 5 GHz

• Global when the standards are ready

• Details yet to be defined

• In the works, ready in 2016

LWA

• LTE using Wi-Fi to boost capacity

• Requires device and core software update only

Carrier Wi-Fi

• What Wi-Fi operators like The Cloud do now

• Best practice in Wi-Fi offload

• Ready, but improving

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LTE-U - the Wild West standard of LTE on Wi-Fi spectrum

• Integration with Licensed LTE: supplemental

downlink (CA with uplink not needed)

• Coexistence with Wi-Fi: dynamic channel

selection and CSAT( based on LTE duty

cycle)

• No support for Listen Before Talk (LBT)

• Based on 3GPP release 10-12

• Not for EU but available in other markets,

such as China, Korea, India and the US

• Fewer changes from licensed LTE

• Earlier commercialization

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LAA-LTE –the yet-to-be stamped future standard of LTE on LE

• Licensed Assisted Access – LTE

• Devices use licensed anchor band when

using Wi-Fi

• Wi-Fi like Coexistence with Wi-Fi: dynamic

channel selection and Listen Before Talk

• Based on 3GPP Release 13

• Compliant with regulatory requirements of

most countries

• Later commercialization

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LWA - LTE and Wi-Fi aggregation or LTE with “Wi-Fi boost”

• Using both LTE and Wi-Fi to achieve the highest

possible capacity for mobile devices

• Proposed technology to be introduced in 3GPP

Release 13

• Uses the same 5 GHz spectrum as LTE-U or

LAA would and additionally, the 2.4 GHz band

• Crucially, LWA would not require any changes

for current Wi-Fi handsets or infrastructure, it

would be a software update

• Uses Wi-Fi only for downlink, LTE carrying all

uplink traffic and potentially, helping with the

downlink

• Both technologies played against their strenghts

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Carrier Wi-Fi

• Carrier grade Wi-Fi has been the hot topic of many conferences and is getting a definition

• It is essentially, a Wi-Fi technology ideally suited for offloading data during peak times

• The Cloud estate is considered one of the most sophisticated Wi-Fi hotspot networks and

as such, often used as an example of a “Carrier grade Wi-Fi” network deployment

• Professionally deployed estate in high demand locations

• Technically advanced with scalable core, dual band Access points with smart antennas,

Passpoint ready, EAP-SIM ready, with central controller and sophisticated user

experience management

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LTE has better spectral efficiency and coverage

• Dynamic link adaptation gives LTE a

slight advantage over Wi-Fi

• Furthermore, comparing IEEE

802.11ac and LTE Rel.12 at 256QAM

gives LTE an 11% advantage, with

WiFi at 6.67bits/symbol and LTE at

7.43bits/ symbol, respectively

• Time to market and market adoption,

scale of deployments and availability

of services being perhaps more

relevant measures

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Co-existence work

• 3GPP work for co-existence with Wi-Fi has just started

• Concerns raised from IEEE/802.11 and WFA how the co-existence use cases are set up

and what scenarios are included

– Co-existence behavior with multiple overlapping deployments should be considered

– Test the networks with multiple clients, wide channels and

– LBT (Listen Before Talk) should be included with exponential back-off, in DL and UL.

– LBT timing rules and thresholds for energy detect that meld with Wi-Fi

– Preamble detection and/or reservation signaling

– KPIs other than just throughput and latency, such as Jitter, Packet loss, Frame retransmission rate,

beacon loss and deferral and power save signaling loss and deferral should be included

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Relevance of 11% in the real world

• Difference between a good AP and a good AP can easily be

50% in performance and the range of minimum quality of

service

• Different configurations in LE deployments can quite easily

gain or lose much more than that

• Having said that, 11% addition to speed or range would be

welcome, but what about cost?

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“Cost” of LTE on LE is unknown

And extremely hard to quantify

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The real world of seamless user experience is a three dimensional

problem, not all of which are always considered

Wi-Fi

LTEOther Wi-Fi

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Final thoughts

Wi-Fi is ready to deploy now

• Excellent coverage and capacity

• Low cost to deploy

• Excellent co-existence mechanisms with other

LE users

• Admission control, band steering, airtime

fairness and fast transition/roaming features

• 802.11ax, 802.11k&r, Passpoint and multiband

• Does not rule out the LTE deployments, or even

the LAA deployments

• Wi-Fi calling

• Perfect neutral host with 100% handset

adoption

LTE on LE is still in the works

• Deployments will likely introduce a hardware

change – further prolonging the adoption

timelines

• Higher cost to design and deploy

• Risk of harming other LE use cases

• Smallcell deployments are Wi-Fi like

Thank you

Star Wars: Return of the Jedi