Millimeter wave opportunities & challenges: an industry ...

Millimeter wave opportunities & challenges: an industry perspective

Carlos Cordeiro

Senior Director/Senior Principle Engineer

Intel Corporation

Data demand

Source: Cisco VNI

2021 data demand forecast

Why millimeter wave (mmWave)?

Primary mmWave spectrum allocation for mobile usages

60 GHz band

57

64

Frequency

(GHz)

E-

band

71

76

28

GHz

band

39

GHz

band

27.5

Unlicensed Licensed

37 GHz

band

E-

band

81

8628.35 37 38.6 40

10-20x greater spectrum availability compared to <

6 GHz

More capacity, lower latency

Improved UX

Where are we in mmWave standardization?

• mmWave (60 GHz) standardization started in IEEE over 10 years ago• The only commercial, consumer mmWave products are based on 11ad

– Proof that major technological barriers have been overcome

• IEEE 802.11ay is the next generation standard after 802.11ad– Under development; currently in draft 1.0

• 3GPP mmWave specifications are still in development• In the remainder of this presentation, we focus on 11ay

– Technical improvements over 11ad– Challenges: technical and market– Where do we go from here?

Item Feature 802.11ad 802.11ay additions

MAC

Net. architecture Infra-BSS, IBSS, PBSS Same

Medium access Scheduled and contention access Multiple channel operation and MIMO

Power saving Adv. power saving techniques Power saving for channel bonding and MIMO

Aggregation A-MPDU and A-PPDU Segmentation and reassembly

Block Ack (BA) Fixed 64 bits BA bitmapCompressed BA

Up to 1024 BA bitmapMulti-TID BA & Unsolicited BA

Security GCMP, multi-band RSNA Fast authentication & association mode

PHY

Modulation SC and OFDM: BPSK, QPSK, 16-QAM, 64-QAM

Non-uniform constellation8-PSK

Channelization Single channel (2.16 GHz) operation

2.16 GHz, 4.32 GHz, 6.48 GHz, 8.64 GHz, 2.16+2.16 GHz and 4.32+4.32 GHz channels

Number of streams One (SISO) Up to 8, supporting SU-MIMO and MU-MIMO

Max data rate 7 Gbps 275 Gbps (4 channels, 8 SSs, short GI, 64-QAM 7/8)

LDPC 672 bits codeword 1344 bit codeword

GI Normal Short, normal and long

Beamforming

Protocol Sector level sweep (SSW) and beam refinement (BRP)

Short SSW, BRP TXSS, Asymmetric BF, Group BF and MIMO BF, first path BF

TRN Single channel training Multiple channel operation and MIMO training

Summary of 11ay enhancements on top of 11ad

Main 11ay PHY enhancements over 11ad

• Channel bonding requires new:– Channelization and TX masks– Packet format– Channel access– Beamforming

• Channel aggregation– Possibly different waveforms for each aggregated

channel– 2.16 GHz + 2.16 GHz and 4.32 GHz + 4.32 GHz,

adjacent or non-adjacent channels

• 11ay (EDMG) packet format– Consists of pre-EDMG modulated fields and EDMG modulated fields

11ay packet format and backward compatibility with 11adED

MG

mo

du

late

d

P

re-E

DM

G m

od

ula

ted

Ncb = 2 Ncb = 3 Ncb = 4

Main 11ay PHY enhancements over 11ad

• SU and downlink MU MIMO– Unique requirements given radio

propagation characteristics, transceiver architecture, and need for directional transmissions

– Value of antenna polarization– Requires changes to beamforming and

channel access

Example without polarization Example with polarization

• Training field– Support channel bonding and MIMO– Support implementations of different

complexities

Main 11ay BF enhancements over 11ad

• MIMO BF– SU- and DL MU-MIMO

training

• BF for asymmetric links– Addresses cases in which

devices have different antenna gains

Beamformed pattern

10log10(n) dB

15dB CPHY compensationMissing Link Margin

Omni Pattern

Main 11ay BF enhancements over 11ad

• BRP TXSS– Sector sweep using BRP

frames– “One stop” training for

TX/RX settings of both stations

• First path beamforming– Positioning applications– 11ay: wide BW Fine

positioning/tracking– Reduce bias in range and

angle measurementsIn

itiat

orRe

spon

der

EDMGBRP-TX packet

feedback

Antenna 1(quasi-omni)

Ant

enna

1

Ant

enna

3

setupEDMGBRP-TX packet

EDMGBRP-TX packet

setup

EDMGBRP-TX packet

Ant

enna

1

Ant

enna

2

Ant

enna

3

EDMGBRP-TX packet

EDMGBRP-TX packet

Antenna 2(quasi-omni)

Ant

enna

2

ackEDMGBRP-RX packet

EDMGBRP-TX packet

Antenna ANT_init

(quasi-omni)

Ant

enna

1

EDMGBRP-TX packet

Ant

enna

2

feedback

EDMGBRP-RX packet

ANT_RX_resp

AWV_RX_resp

AWV_RX_init

ANT_TX_respAWV_TX_resp

ANT_init AWV_TX_init

Ant

enna

A

NT_

init

(AW

V_TX

_ini

t)

Ant

enna

A

NT_

TX_r

esp

(AW

V_TX

_res

p)

AntennaANT_RX_resp

Antenna ANT_init

Remaining (open) challenges are non-technical

Significant path loss compared to lower bands

Significant penetration loss

Lower coverage compared to lower bands

NLOS transmissions

Blockage

Power consumption

Cost

Killer app (for high volume)

Placement in small form factor devices (e.g., phones)

Industry has shown that these have been overcome

or can be dealt with

Progress has been made, but market is not there yet

Significant progress, but more remains towards mass market

Standards evolution

• 11ay offers a significant evolution compared to 11ad– Rates in excess of 100 Gbps– Latencies < 1ms

• A natural question is what are the next “moonshot” technologies

• Too early to say, but in my personal view they include:– New modulations (e.g., OFDMA, SC-FDMA)– UL MU-MIMO– Spatial reuse improvements– New applications: radar, gesture detection, location, etc.

• mmWave has come a long way in the last 10-15 years• Market is interested in adopting mmWave for a variety

of use cases – Commercially products based on 11ad are available today

(e.g., for VR/AR applications, networking, backhaul)– 5G mmWave gaining steam

• IEEE and 3GPP standards can/should collaborate• However, mmWave is not out of the woods yet

– Market is maturing, but non-technical challenges remain

Conclusions

• Tutorials:– C. Cordeiro and S. Nandagopalan, “Next Generation Multi-Gbps

Wireless LANs and PANs,” in IEEE Globecom, Dec 2010.– C. da Silva and C. Cordeiro, “IEEE 802.11ay: Introduction to the first

standard for 100 Gbps Wi-Fi,” in IEEE Globecom, Dec 2017.

• Survey papers:– T. Nitsche, C. Cordeiro, A. Flores, E. Knightly, E. Perahia, J. Widmer,

“IEEE 802.11ad: directional 60 GHz communication for multi-Gigabit-per-second Wi-Fi,” in IEEE Communications Magazine, Dec 2014.

– Y. Ghasempour, C. da Silva, C. Cordeiro, E. Knightly, “IEEE 802.11ay: Next-Generation 60 GHz Communication for 100 Gb/s Wi-Fi,” in IEEE Communications Magazine, Dec 2017.

References