1. Radio Waves: Spectrum as a Resource Week 10 (Wednesday) JMCO 235

2. Radio Wave ITU’s Definition: “Radio waves are electromagnetic waves of frequencies arbitrarily lower than 3 000 GHz, propagated in space without artificial guide.” International Telecommunication Union (ITU) Radio Regulation: http://www.itu.int/publ/R-REG-RR-2004/en http://www.itu.int/publ/R-REG-RR-2004/en

3. Characteristics of a Wave Amplitude and Frequency Radio wave is also a type of ‘wave.’ (And electromagnetic wave is also a type of ‘wave’)

4. What is Amplitude? Amplitude ( 진폭 ) is the magnitude of change in the oscillating variable, with each oscillation, within an oscillating system. In physics, the amplitude of a sound wave or electrical signal is its strength.

5. What is Frequency? Frequency ( 진동수 / 주파수 ) is the number of occurrences of a repeating event per unit time. In physics, the frequency of a sound wave or a radio wave is the number of times it vibrates within a specified period of time.

6. Frequency vs. Amplitude

7. Frequency vs. Time Question: KBS 2FM's frequency is 89.1 MHz. What does this mean, and what period does this correspond to? Solution: The metric prefix M- is mega-(millions). The radio waves emitted by KBS 2FM station's transmitting antenna vibrate 89.1 million times per second. This corresponds to a period of T (period) = 1/f = 0.011 x 10 -6 sec. = 1.11x10 -8 sec. This example shows the reason why we normally speak in terms of frequency rather than period: it would be painful to have to refer to such small time intervals routinely. Of course, you can abbreviate by telling people that KBS 2FM's period is 11.1 nanoseconds, but most people are more familiar with the big metric prefixes than with the small ones.

8. How Data is Transmitted There are a few ways of transmitting data. Most traditional ways are AM and FM. AM stands for amplitude modification ( 진 폭변조 ) FM stands for frequency modification ( 주파수변조 )

9. Data Transmission: AM vs. FM

10. Three Phenomena of Radio Waves Radio waves interact with objects in three principle ways: 1.Reflection – A radio wave bounces off an object larger than its wavelength. 2.Diffraction – Waves bend around objects. 3.Scattering – A radiowave bounces off an object smaller than its wavelength.

11. Back to Radio Waves and Frequency Higher frequency radio waves tend to propagate straight. Lower frequency radio waves tend to reflect and diffract easily.

12. Typical usage by band Notice that higher bands are used for complex data transmission and lower bands are for audio transmission

13. Radio Wave as a Common Resource Radio wave is a common resource. It does not exhaust after usage (different from oil and coal) But it cannot be used by too many users at the same time (interference; 혼신 ) Certain bandwidths are more popular (e.g., VHF, UHF) For this reason, most countries regulate how radio wave is used by allocation.

14. Process of Radio Wave Management in Korea 1. Secure Resource Allocation (deciding for what purpose each spectrum is used) by WRC (World Radiocommunication Conference; organized by ITU) ITU (WRC) allocates spectrum for three regions (1: Europe & Africa, 2: the Americas & Pacific islands, 3: Asia & Australia) Last WRC was held in 2007.

15. Process of Radio Wave Management in Korea 2. Local Allocation & Assignment KCC (Korea Communications Commission) determines details for spectrum allocation. KCC also assigns spectrum: Offers license to a particular user to use certain spectrum

16. Process of Radio Wave Management in Korea 3. Management & Maintenance (by KCC & subsidiaries) KCC Issues license to stations ( 무선국 허가 ) Radio Research Agency ( 전파연구소 ) certificates, tests, and conducts follow-up management of broadcasting and communications equipment ( 인증 ) Central Radio Management Office ( 중앙전파관리소 ): Inspection of Radio Stations (with Korea Radio Promotion Agency), Investigation of interferences, Monitoring of mobile radio frequencies, Investigation of radio frequency spectrums (for interference and illegal usage), etc.

17. Price for Assignment Based on Radio Wave Act Section 2, 10, 11, & 12 ( 전파법 제 2 조, 10-12 조 ), KCC assigns spectrum(s) to a user. KCC reviews the economical value of the spectrum, the impact of the proposed business, needs for the spectrum, etc. when it assigns a spectrum. The usual price is within 3% of the expected sales made. In certain cases, allocation is done for free.

18. Examples of Assignment by KCC Assignment for Price  IMT-2000 (‘03. 12) Lease of 40MHz for 15 yrs. SKT: KRW 1.3 Trillion KTF: KRW 1.3 Trillion LGT: KRW 1.15 Trillion LGT returned its spectrum (‘06. 7)  Satellite DMB (‘04. 7) Lease of 25MHz for 12 yrs. SKT: KRW 7.8 Billion  WiBro (‘05. 4) Lease of 100MHz for 7 yrs. SKT: KRW 125.8 Billion KT: KRW 117 Billion Assignment for Free  Cellular (‘83) SKT 50MHz SKT’s megerger of Shinsegi Telecom.  PCS (‘97) KTF 40MHz KTF’s merger of Hansol Mobile KRW: Korean Won

19. Changing Environment - 1 Past: Radio Waves were exclusively used for telecommunication. Today: Virtually all machines use radio waves (e.g., wireless mouse, Bluetooth equipment, RF card, etc.) This calls for effort to prevent interference (to prevent malfunction)

20. Changing Environment - 2 Past: Telecommunication service provided either voice or data. Today: Multimedia service (which requires more data to be transmitted) Higher demand for higher spectrum is expected. ITU predicts stronger demand for mobile communication in the 1.28-1.72GHz spectrum by 2020.

21. Changing Environment - 3 Digital convergence allows different services (voice, broadcast, Internet, wireless communication) to be provided by one single service provider. This makes hard for the government to estimate the value created by any given spectrum (and hard to set the price for spectrum allocation)

22. Changing Environment - 4 Shift from Analog to Digital Television means that the spectrum used for analog television will become available. Old analog television technology used a broad spectrum, while digital television uses smaller spectrum. This large spectrum should be re-allocated wisely.

23. Trend 1: Reassign & Reallocate Under-utilized spectrums are returned and reassigned for new services (such as 4G mobile communication) –U.S.: Military use spectrum (1.7/2.1GHz) is now assigned for 3G mobile comm. –Japan: Reassignment of 800-900 MHz spectrum. Old analog TV spectrums will be reallocated and/or reassigned. (U.S., Japan, United Kingdom) Reassigning popular spectrums (under 1GHz) to new players to encourage competition –U.K., France: Part of the spectrums returned by established businesses are allocated to new businesses. –Germany: Part of 900MHz spectrum used by military is now allocated to new businesses.

24. Trend 2: Market-Driven Solution Other countries are auctioning off spectrums. FCC of the U.S. has been doing this since 1993: http://wireless.fcc.gov/auctions/default.htm?job=auctions_home http://wireless.fcc.gov/auctions/default.htm?job=auctions_home New Zealand (1989-), Australia (1993), Sweden (2007), Norway (2007) are also auctioning off spectrums.

25. Trend 3: Flexibility to Users More flexibility for using spectrum is given to users. However, this is done in the way the market is not distorted. In the past: “Use this spectrum only for ABC purpose” Today: “Use this spectrum within the range of ABC, DEF, or GHI purposes” U.S., U.K., Australia are doing this (for certain spectrums)

26. Golden Spectrum: 800-900MHz Lower frequencies means easier reflection and defraction. 800-900MHz requires less stations/towers. This means less money for running the business.

27. Tension Surrounding the Golden Spectrum By June 2011, SKT’s 20MHz (of 50MHz) in the 800 MHz spectrum will be returned to the government (KCC). 20MHz in the 900 MHz spectrum (currently used by public agencies) will also be returned. LG Telecom, (newly merged) KT, and other small/new companies are aruging that they should get this frequency. KCC considers auctioning of these spectrums.

28. Auctioning Spectrums in Korea In the past, government officials determined the value of spectrums and set the price for lease. (This led to corruption in PCS, and too high pricing for IMT-2000) The update of Radio Wave Act ( 전파법 개정 안 ) is being delayed at the congress. This delay is making some think that auctioning/reassignment of some spectrums (e.g., 800MHz and 2.1GHz) not possible this year. Delay in reassignment means delay in planning business.

29. What should happen? Hopefully, update of the radio wave act will happen early enough. (Again, hopefully,) auction will allow businesses to write a reasonable price for their business. (In some cases, they don’t)

30. Appendix: Names of Band by Freuqency ULF (30 ~ 300Hz, ultra low frequency) ELF (300 ~ 3000Hz, extremely low frequency, 극초장파 )) VLF (3 ~ 30KHz,very low frequency, 초장파 ) LF (30 ~ 300KHz, low frequency, 장파 ) MF (300 ~ 3000KHz, medium frequency, 중파 ) HF (3 ~ 30MHz, high frequency, 단파 ) VHF (30 ~ 300MHz, very high frequency, 초단파 ) UHF (300 ~ 3000MHz, ultra high frequency, 극초단파 ) SHF (3 ~ 30GHz, super high frequency, 마이크로파 ) EHF (30 ~ 300 GHz, extremly high frequency, 밀리미터파 ) Band: 주파수대역