ECS 455 Chapter 1 Introduction

Transcription

1 ECS 455 Chapter 1 Introduction 1.3 Spectrum Allocation 1 Dr.Prapun prapun.com/ecs455 Office Hours: BKD, 6th floor of Sirindhralai building Tuesday 14:20-15:20 Wednesday 14:20-15:20 Friday 9:15-10:15

2 Electromagnetic Spectrum 3 MHz 3 GHz 100 m 10 cm m/s c [Gosling, 1999, Fig 1.1 and 1.2] f Wavelength Frequency 2

3 [ Radio-frequency spectrum Commercially exploited bands m/s c f Frequency Wavelength Note that the freq. bands are given in decades; the VHF band has 10 times as much frequency space as the HF band.

4 Cellular Bands Cellular phone networks worldwide use a portion of the radio frequency spectrum designated as ultra high frequency (UHF) (300 MHz to 3 GHz) The UHF band is also used for television, GPS, Wi-Fi, and Bluetooth transmission. Due to historical reasons, radio frequencies used for cellular networks differ in the Americas, Europe, and Asia. Frequency bands that are currently identified for IMT (International Mobile Telecommunications) in all three ITU Regions: MHz MHz MHz MHz MHz MHz Additional frequency bands identified for IMT on a Regional or National basis: MHz (Region 2) MHz (9 countries in Region 3: Bangladesh, China, Rep. of Korea, India, Japan, New Zealand, Papua New Guinea, Philippines and Singapore.) MHz (Over 80 Administrations in Region 1 plus 9 in Region 3 including India, China, Japan and Rep. of Korea). 4 [ ]

5 ITU Regions The ITU divides the world into three ITU regions for the purposes of managing the global radio spectrum. Region 2 Region 1 Region 3 5

6 FDD and TDD LTE frequency bands 6 FDD LTE frequency band allocations WIDTH OF DUPLEX LTE BAND BAND GAP UPLINK (MHZ) DOWNLINK (MHz) BAND SPACING NUMBER (MHZ) (MHZ) (MHZ) / n/a TDD LTE frequency band allocations LTE BAND NUMBER ALLOCATION (MHZ) WIDTH OF BAND (MHZ) [

7 Spectrum Allocation Spectral resource is limited. Most countries have government agencies responsible for allocating and controlling the use of the radio spectrum. Commercial spectral allocation is governed globally by the International Telecommunications Union (ITU) ITU Radiocommunication Sector (ITU-R) is responsible for radio communication. in the U.S. by the Federal Communications Commission (FCC) in Europe by the European Telecommunications Standards Institute (ETSI) in Thailand by the National Broadcasting and Telecommunications Commission (NBTC; คณะกรรมการก จการกระจายเส ยง ก จการโทรท ศน และก จการ โทรคมนาคมแห งชาต ; กสทช.) Blocks of spectrum are now commonly assigned through spectral auctions to the highest bidder. 7

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9 Thailand Freq. Allocations 9 [ ]

10 ตารางก าหนดคล นความถ แห งชาต 10 [ nbtc.go.th/spectrum_management/แผนแม บท/ตารางก าหนดคล นความถ แห งชาต.aspx ]

11 National Table of Frequency Allocation 11 [ nbtc.go.th/spectrum_management/แผนแม บท/ตารางก าหนดคล นความถ แห งชาต.aspx ]

12 Thailand Freq. Allocations Chart 12

13 Spectrum Allocation 13 Spectrum is a scarce resource. Radio spectrum will be the first of our finite resources to run out, long before oil, gas or mineral deposits. Spectrum is allocated in chunks in frequency domain. Chunks are licensed to (cellular/wireless) operators. Within a single cellular operator, the chunk is further divided into many channels. Each channel has its own band of frequency. Mobile networks based on different standards may use the same frequency chunk. For example, AMPS, D-AMPS, N-AMPS and IS-95 all use the 800 MHz frequency chunk. This is achieved by the use of different channels.

14 Oct 2012: Thailand 2.1GHz Auction 4.5bn baht per license (freq chunk) 1 license (chunk) = 5 MHz (UL) + 5 MHz (DL) 450 million baht per MHz 30 million baht per MHz per year 14

15 Nov 2015: Thailand 1800MHz Auction 40bn baht 15 MHz (UL) + 15 MHz (DL) 1.3 billion baht per MHz 74 million baht per MHz per year ( 2.5 ) (15 years) (18 years) 15

16 Dec 2015: Thailand 900MHz Auction 76bn baht 10 MHz (UL) + 10 MHz (DL) 3.8 billion baht per MHz 250 million baht per MHz per year ( 3 ) Nov years Dec years (forfeit) 16

17 Interesting Book Spectrum Wars: The Policy and Technology Debate Designed to help you ensure that your company wins the battle for the spectrum, this text maps out the strategies required for structuring entry and operations in the spectrum. It offers advice on how to master the lobbying, technical, regulatory, legal and political tools needed for success. [Manner, 2003] 17

18 ECS 455 Chapter 1 Introduction 1.4 Unlicensed bands 18 Dr.Prapun prapun.com/ecs455 Office Hours: BKD, 6th floor of Sirindhralai building Tuesday 14:20-15:20 Wednesday 14:20-15:20 Friday 9:15-10:15

19 Unlicensed bands Frequency bands that are free to use according to a specific set of etiquette rules. The purpose of these unlicensed bands is to encourage innovation and low-cost implementation. Many extremely successful wireless systems operate in unlicensed bands, including wireless LANs, Bluetooth, and cordless phones. Major difficulty: If many unlicensed devices in the same band are used in close proximity, they generate much interference to each other, which can make the band unusable. 19

20 20 Unlicensed bands (2) Unlicensed spectrum is allocated by the governing body within a given country. Often countries try to match their frequency allocation for unlicensed use so that technology developed for that spectrum is compatible worldwide. The following table shows the unlicensed spectrum allocations in the U.S. (ISM = Industrial, Scientific, and Medical) 900 MHz 2.4 GHz 5.8 GHz 5 GHz 5 GHz 5.8 GHz (U-NII = Unlicensed National Information Infrastructure)

21 [TseViswanath, 2005, Section 4.1] Licensed vs. Unlicensed Spectra 21 Licensed Typically nationwide. Over a period of a few years. From the spectrum regulatory agency. Bandwidth is very expensive. No hard constraints on the power transmitted within the licensed spectrum but the power is expected to decay rapidly outside. Provide immunity from any kind of interference outside of the system itself. Unlicensed For experimental systems and to aid development of new wireless technologies. Very cheap to transmit on. There is a maximum power constraint over the entire spectrum. Have to deal with interference.

22 Ex. Wi-Fi Standards a/b/g/n operate in the 2.4 GHz band n optionally supporting the 5 GHz band. The new ac standard mandates operation only in the 5 GHz band. 2.4 GHz band is susceptible to greater interference from crowded legacy Wi-Fi devices as well as many household devices. The 5 GHz band has relatively reduced interference and there are a greater number of nonoverlapping channels available (25 non-overlapping channels in US) compared to the 2.4 GHz band (3 non-overlapping channels in the US). 22

23 Section (Channel Numbering of operating channels) of the IEEE Std (2012) states In a multiple cell network topology, overlapping and/or adjacent cells using different channels can operate simultaneously without interference if the distance between the center frequencies is at least 25 MHz. 23 [

24 24 5 GHz Band Channels

25 Unlicensed 60 GHz Frequency Band A lot of bandwidth available Worldwide spectrum availability 25 Even for the smallest allocation, there is more than 3 GHz of bandwidth available, and most regions allow use of at least 7 GHz. In comparison, the 5 GHz unlicensed band has about 500 MHz of total usable bandwidth. The 2.4 GHz band has less than 85 MHz of bandwidth in most regions.

26 ECS 455 Chapter 1 Introduction 1.5 LTE in Unlicensed Spectrum 26 Dr.Prapun prapun.com/ecs455 Office Hours: BKD, 6th floor of Sirindhralai building Tuesday 14:20-15:20 Wednesday 14:20-15:20 Friday 9:15-10:15

27 LTE in unlicensed spectrum The use of the 4G LTE radio communications technology in unlicensed spectrum, such as the 5 GHz band already populated by Wi-Fi devices. (400 MHz 3.8 GHz) LTE (5 GHz) 27

28 LTE Unlicensed has Multiple Flavors LTE in unlicensed spectrum (LTE-U) Based on 3GPP Rel. 12 Target early mobile operators deployments in USA, Korea and India License Assisted Access (LAA) Defined in 3GPP Rel. 13 as part of LTE Advanced Pro Target deployments in Europe, Japan, & beyond. 28

29 LTE-U: Controversy June 2015: Google sent the FCC a protest August 2015: the Wi-Fi Alliance also voiced opposition The technical concern with LTE-U is that LTE is a rude technology. WiFi includes a politeness protocol that LTE lacks. WiFi will back off if it senses interference from other users. Eventually rude LTE operating in WiFi s polite bands could take over the band. 29

30 LAA: Fair Wi-Fi coexistence A better neighbor to Wi-Fi than Wi-Fi itself 30