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 oamagd@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 8 MHz 5.6 MHz 26 MHz 779 787 863 868.6 902 928 MHz US (max erp <=1 W) China EU 6.5 MHz (max erp <= 10 mW) Korea Region Tx power regulations 917 923.5 US Max e.r.p. <= 1 W 13.8 MHz EU max erp <=14 dBm PSD <= -4.5 dBm/100KHz (863~868.6MHz) Japan PSD <= 6.2 dBm/100KHz (865~868MHz) 929.7 915.9 928 MHz Korea 3 mW or 10 mW (920.6~923.5MHz and six (Max BW = 1MHz) 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 9

WLAN Channelization in the 5 GHz 5170 5330 5490 5710 5735 5835 MHz MHz MHz MHz MHz MHz 100 104 108 120 124 128 132 136 140 149 153 157 161 165 112 116 IEEE channel # 36 40 44 48 52 56 60 64 20 MHz 40 MHz 80 MHz Channelization in US 10

Emerging of New Technologies • The availability of spectrum for unlicensed use has eliminated the barrier for the introduction of 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 of 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 of 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 WLAN Card for rent Price $50 • During the 49 th 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 18

The Present 19

During the next few years the use of 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 HT, VHT, White Legacy mmWave Sub 1 G HEW Spaces A/B/G N AF AH AD AC AY AX 21

802.11 Architecture Overview • Multiple Over the Air PHY options • One common MAC based on CSMA/CA a ad af ah ax b g n ac 802.11 MAC 22

Band Max Wavefor MIMO Channel Coding Range Rate m Width 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 5 600 Mb/s OFDM 4x4 20/40 BCC and 100 m GHZ MHz LDPC ad 60 GHz5 7 Gb/s OFDM N/A 2 GHz BCC and 10 m LDPC ac 5 GHz 6.9 Gb/s OFDM 8x8 20/40/80/ BCC and 100 m 160 MHz LDPC af 700 MHz 569 Mb/s OFDM 4x4 6,7, and 8 BCC and 1 Km MHz LDPC ah <1 GHz 346 Mb/s OFDM 4x4 1/2/4/8/1 BCC and 1 Km 6 MHz LDPC ax 2.4 and 5 ?? OFDMA ?? Same as in BCC and 100 m GHz ac LDPC 802.11ax is work in progress 23

Then Something happened …and everything has changed 24

Traffic grew exponentially and Continues to grow Forcing carriers to rely on Wi-Fi (unlicensed spectrum) to off-load data 25

In 2014 Wi-Fi Traffic was 16 times the Cellular one UK Data carried in PB per month 538.5 MHz 1600 available 538.5 MHz available 1200 Wi-Fi 800 1440 PB Cellular 1209 PB 400 602 MHz 602 MHz available available 74 PB 44PB 0 Cisco VNI, 2014 average Infrastructure Report, June 2014 Source: Andy Gowans (UK regulator) presentation: https://mentor.ieee.org/802.18/dcn/16/18-16-0016-01-0000-ofcom- 26 future-spectrum-requirements.pptx

Economic Impact of Unlicensed Spectrum 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 27

The Future 28

Everything looks cool; where is the problem? Someone came up with a brilliant idea: Let’s run LTE in the unlicensed spectrum 29

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 100 104 108 112 116 120 124 128 132 136 140 144 149 153 157 161 165 169 173 177 181 36 40 44 48 52 56 60 64 68 72 76 80 84 88 92 96 Channel # 20 MHz 40 MHz 80 MHz 160 MHz UNII-2 Extended UNII-3 UNII-1 UNII-2 5250 5350 5470 5725 5825 5925 MHz MHz MHz MHz MHz MHz Available TDWR channels To become available Set of indicated channels as Full 5GHz Band 33

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