The Use of Unliscenced Spectrum for Wireless Communications Past, - - PowerPoint PPT Presentation

The Use of Unliscenced Spectrum for Wireless Communications Past, Present, and Future

Osama Aboul-Magd

• amagd@gmail.com

1

• Disclaimer: This presentation represents my

views, not those of my employer.

2

Introduction

• What is the Radio Spectrum?

– The range of electromagnetic frequencies from approximately 300 KHz to 300 GHz

• Used for military and public safety

applications, broadcast television, navigation and aviation communications, radar, and GPS devices.

• Regulated and managed by government

3

4

Licensed Spectrum

• The term licensed spectrum refers to

frequency bands that can be used exclusively by a licensed operation.

• A license defines the frequency range

and geographic locations in which the spectrum can be utilized.

• License are usually obtained by

government-held auction

– Through the end of 2008, spectrum auctions have raised $54 billion in revenue to the US government.

5

Unlicensed Spectrum

• Unlicensed spectrum refers frequency bands

for which no exclusive licenses are granted

• Unregistered users potentially may operate

wireless devices without authorization as long as adhering to the regulations, e.g. maximum power leve; in-door, out-door, or both.

• Users are subject to interference with by other

users.

6

The Past

7

Unlicensed Spectrum Allocation

• Before 1985 devices were approved on a case-

by-case regulatory process.

– Wireless Microphones, garage door opener, remote control, cordless phone, etc.

• In 1985, The FCC (in the US) eliminated the

case-by-case regulatory process.

• Opened up new spectrum for unlicensed use

at < 1 GHz (902-928 MHz), 2400 – 2483.5 MHz, and 5725 – 5850 MHz.

8

Allocation of Unlicensed Spectrum is not Globally Uniform

902 928 MHz 917 923.5 929.7 779 787 863 868.6 8 MHz 5.6 MHz 26 MHz 6.5 MHz China (max erp <= 10 mW) EU US (max erp <=1 W) Korea Japan (Max BW = 1MHz)

Region Tx power regulations US Max e.r.p. <= 1 W EU max erp <=14 dBm PSD <= -4.5 dBm/100KHz (863~868.6MHz) PSD <= 6.2 dBm/100KHz (865~868MHz) Korea 3 mW or 10 mW (920.6~923.5MHz and six 200 KHz channels below 920.6 MHz) China Max e.r.p. <= 10 mW Japan 1mW , 20 mW or 250 mW (915.9~929.7MHz) Max BW <= 1 MHz

915.9 928 MHz 13.8 MHz

9

WLAN Channelization in the 5 GHz

10

140 136 132 128 124 120 116 112 108 104 100 165 161 157 153 149 64 60 56 52 48 44 40 36 IEEE channel # 20 MHz 40 MHz 80 MHz 5170 MHz 5330 MHz 5490 MHz 5710 MHz 5735 MHz 5835 MHz

Channelization in US

Emerging of New Technologies

• The availability of spectrum for unlicensed use

has eliminated the barrier for the introduction

• f new technologies
• enabled the emergence of new technologies

– IEEE 802.11 WLAN and Wi-Fi – IEEE 802.15 WPAN and Blue Tooth/Zigbee

• Wi-Fi Distinguished itself by allowing

inexpensive wireless internet access.

11

The Way We Were

• Attending a conference

required the collection

• f multi-volume

proceedings.

12

The Way We Were

• Meetings were

conducted using projector and transparencies

• No way to check news,

weather, or even change travel arrangement.

13

The Story of Wi-Fi

14

…A humble start

15

The Story of Wi-Fi

• The standardization of Wi-Fi started as a sub-committee
• f 802.4 (Token Bus)

– 802.4c – From July 1988 to July 1990

16

From 802.4 to 802.11

• During the spring 1990 it became clear that the

Token Bus protocol could not adapt to a radio channel.

• IEEE 802.11 WG was born in 1990

17

My First Encounter with Wi-Fi

• During the 49th IETF meeting in San Diego (December

2000), Cisco was offering WLAN cards for rent.

– The meeting was attended by about 2800 engineers – Effective way to introduce new technology

WLAN Card for rent Price $50

18

The Present

19

During the next few years the use

• f Wi-Fi continued to grow in its

traditional unlicensed bands (mainly 2.4 GHz) and its traditional markets consumer and enterprise, but hardly any new spectrum

20

IEEE 802.11 PHY Technologies

IEEE 802.11 Legacy A/B/G HT, VHT, HEW N AC AX mmWave AD AY White Spaces AF Sub 1 G AH

21

802.11 Architecture Overview

• Multiple Over the Air PHY options
• One common MAC based on CSMA/CA

802.11 MAC b g n ac ad a af ah ax

22

23

Band Max Rate Wavefor m MIMO Channel Width Coding Range

a 5 GHz 54 Mb/s OFDM N/A 20 MHz BCC 100 m b 2.4 GHz 11 Mb/s DSSS N/A 20 MHz BCC 100 m g 2.4 GHz 54 Mb/s OFDM N/A 20 MHz BCC 100 m n 2.4 and 5 GHZ 600 Mb/s OFDM 4x4 20/40 MHz BCC and LDPC 100 m ad 60 GHz5 7 Gb/s OFDM N/A 2 GHz BCC and LDPC 10 m ac 5 GHz 6.9 Gb/s OFDM 8x8 20/40/80/ 160 MHz BCC and LDPC 100 m af 700 MHz 569 Mb/s OFDM 4x4 6,7, and 8 MHz BCC and LDPC 1 Km ah <1 GHz 346 Mb/s OFDM 4x4 1/2/4/8/1 6 MHz BCC and LDPC 1 Km ax 2.4 and 5 GHz ?? OFDMA ?? Same as in ac BCC and LDPC 100 m

802.11ax is work in progress

Then Something happened

24

…and everything has changed

Traffic grew exponentially and Continues to grow

25

Forcing carriers to rely on Wi-Fi (unlicensed spectrum) to off-load data

In 2014 Wi-Fi Traffic was 16 times the Cellular one

26

1209 PB 1440 PB 74 PB 44PB 400 800 1200 1600

Wi-Fi Cellular

UK Data carried in PB per month

Infrastructure Report, June 2014 Cisco VNI, 2014 average 602 MHz available 602 MHz available 538.5 MHz available 538.5 MHz available

Source: Andy Gowans (UK regulator) presentation: https://mentor.ieee.org/802.18/dcn/16/18-16-0016-01-0000-ofcom- future-spectrum-requirements.pptx

Economic Impact of Unlicensed Spectrum

27

Source: Assessment of The Economic Value of Unlicensed Spectrum in the United State – Dr Rauk Katz, Feb. 2014 Conclusion: Dr. Katz’s study concludes that unlicensed spectrum generated $222 billion in value for the US economy in 2013 and contributed $6.7 billion to US GDP over the same period

The Future

28

Everything looks cool; where is the problem?

29

Someone came up with a brilliant idea: Let’s run LTE in the unlicensed spectrum

The Birth of unlicensed LTE

• 3 Variations

– LTE-U: a pre-standard solution based on a duty cycle. – LTE-LAA a standard solution developed at the 3 GPP and employs an access procedure similar to Wi-Fi (listen before talk and backoff – MulteFire developed by few industry players with no anchor channel in a licensed band.

30

LTE-U and LTE-LAA Operation

• Using LTE carrier aggregation aggregating channels in the licensed

and unlicensed bands

• Control and synchronization information are transmitted over the

licensed channel.

31

And Let’s not forget the

5G

32

And they all plan to operate in the 5GHz band

33

144 140 136 132 128 124 120 116 112 108 104 100 165 161 157 153 149 64 60 56 52 48 44 40 36 Channel # 20 MHz 40 MHz 80 MHz 160 MHz UNII-1 UNII-2 UNII-2 Extended UNII-3 5250 MHz 5350 MHz 5470 MHz 5725 MHz 96 92 88 84 80 76 72 68 169 173 177 181 5825 MHz 5925 MHz

Available TDWR channels To become available Set of indicated channels as Full 5GHz Band

A Couple of Trends

• Unlicensed bands are expected to become

more crowded with increasing role in 5G.

• Pending successful coexistence, Wi-Fi is not

expected to be the only networking technology in the unlicensed band(s)

• On the other hand, Wi-Fi services is offered by

Wi-Fi proponents as an alternative to cellular, e.g. Google Fi.

34