Review of propagation in terrain

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Presentation 15

• Review of propagation in terrain
• Community radio Organizations
• Calculation of Coverage of Community Stations
• Points to cover on National Reports
• Homework 5 due Monday March 10
• Papers on Chinas positions on Telecom.
  Professor Kaili Kahn

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Longley-Rice Propagation Models
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With 300 M tower at 50 km the 1 kW e.r.p. gives
42.5 dBu
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(No Transcript)
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Community Radio Stations

• Nairobi, Kenya April 2005
• AMARC Africas Pan-African Community Radio
  Conference Calls for Community Radio Fund
• More than 100 community radio representatives
  from 27 African countries resolved to create an
  African community radio fund at the just-ended
  3rd Pan African Conference on Community Radio
  held in Nairobi, Kenya. The Community Radio Fund
  will support the sector through equipment
  provision and training.
• Conference deliberations which began on Monday
  April 18th focused on the role of local content
  in bringing about sustainable development in
  communities and on emerging issues in the sector
  such as financing and skills development
• Delegates agreed to strengthen the AMARC Africa
  network through continuing to sensitize and
  empower women from grassroots level about their
  participation in CR so that they can hold
  decision-making and leadership positions in their
  communities.

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Coverage of the 1000 FM radio station

• The 1000 community radio broadcast station works
  at a frequency of 100 MHz. The bandwidth is 180
  kHz and requires 10 dB C/N for good reception.
  The transmit antenna has 4 dB gain. The receivers
  have a total noise temperature of 700 deg. K.
• (a)   How much effective area does the receive
  antenna have? Its gain is 1 dB.
• (b)   What range will you have with the 75-Watt
  FM transmitter?

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Propagationat150 MHz
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The effective area of the dipolewire antennas
at low frequency give large antenna areas
For our case of 1 dB at 100 MHz Aeff l2
Gr/4p l 3 x 108/100x106 3 Meters
G 1 dB gt 1.26 Aeff 3 x 3 x 1.26/ 4p
0.9 M2
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How much power do we need?The FM receiver uses
180 KHz and has a 700 deg noise temperature.B
180kHzgt52.5 dBHz T 700 deg K gt28.4dBK .

• We need kTB C/N -228.6 28.453.5 10
• -136.7 dBw
• The antenna area is .9 M2 gt -0.4 dB
• We need -136.7 (-.4) -136.3 dBW/M2
• But the charts are in dBu not dBW/M2

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Converting Units of Signal Strength

• Power Density W Watts/ M2
• Field Strength E Volts/M
• Power Flow is E x H in free space E is
  Perpendicular to H and H E /120p E /377
• 377 ohms is the free space impedance
• Therefore W E2/120p E sqrt (120p x W)
• dBu means dB relaive to 1 m volt//M
• Power density Wm volt/M (10-6)2/120p
  -145.76
• 0 dBu -145.76 dBw/M2

• We need -136.7 (-.4) -136.3 dBW/M2
• Therefore we want -136.3145.76 9.46 dBu

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What is the EIRP of our station?

• 75 Watt and 4 dB gain transmitter gives an EIRP
  of..
• 18.7 4 22.7 dBW. The charts are for 30
  dBW.
• Therefore were transmitting 30 22.7 7.3
  dB less power than the chart is for.
• Since we want 9.46 dBu signal strength
• On the chart we want 7.3 dB higher power to make
  up for our weaker transmitter or
• 9.46 7.3 16.76 dBu the level on the chart

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For 16.76 dBu(green line)we get range.. tower
height 19 km _at_ 8M ht40 km _at_ 16M ht150 km _at_ 600M
ht note the actual power level is more than
51dB below Free Space propagation(purple line)
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Propagation450Mhzto 1000 MHz
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Homework 5 due Monday, March 10

• I. Find the expected coverage of a WiMax base
  station mounted on a mountain top. It has a power
  of 1 watt a bit rate of 3 Mb/s and an antenna
  gain of 8 dB. Use the propagation charts of 1000
  MHz, above. The modulation is QPSK with Eb/No
  9.5 dB.
• Find the range for a tower height of 150 meters
  and a receiver with an antenna with 2.7 dB gain
  and temperature of 500 deg K.
• Find the range for a tower height of 600 meters
  and a receiver antenna with an effective area of
  ½ meter square and temperature of 500 deg K.
• II. The VHF band had a TV broadcast station with
  2 kW output power on a signal requiring 35 dB
  C/N in a 5 MHz bandwidth.
• Using the 150 MHz chart , what is the coverage to
  a TV receiver with 500 deg K temperature and an
  antenna gain of 20 dB. The transmitter is on a
  hill 300 ft above the terrain.
• What power is needed to reach the same range with
  the 10 Mb/sec transmission with QPSK and 9.5 dB
  Eb/No. The transmitter is on the same hill and
  the receiver antenna and temperature are the same
  as in (a).

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Final Presentations Schedule

• Yousef Qassim Sri Lanka Mar 10
• Krit Supradith ASEAN Markets Mar 10
• Pete Riley Brazil Communities Mar 10
• John Anasis Ghana Mar 10
• N. Mackowski East Timor Mar 12
• Jesus Gonzales-M Mexico Mar 12
• Ernest Ventura Philippines Mar 12
• Phil Miller Africa Union Mar 12
• Cathy Sae-Wong South America Union Mar 12

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Issues for Country Reports

• How does the target rural population do as far as
  education, health and income?
• During the Colonial Era What were the crops or
  minerals of interest to the world traders?
• What constraints are there on them owning and
  operating the farms or mines for export income?
• What value added work could they create with
  their resource advantage?
• What local jurisdiction (national, state, or
  city is most responsive to their interests.)
• Is there an International Peace-keeping Force
  present?

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Cultural Issues

• Give a general description of the culture with
  history and pictures
• What are the local, national and international
  (trade) languages?
• What are the sites and monuments of their
  culture? Does this and/or scenic sites offer
  tourist income opportunities?
• What is the traditional governing structure of
  the society?
• How widespread is the language/culture in the
  nation?
• Are there family links to cities and other
  nations?

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Items for Development Plan

• A network plan to connect the rural region with
  low-cost WIMAX and cell phone links. VSAT where
  needed.Use local labor where possible.
• Public access through roving cell phones and
  internet cafes or kiosks.
• Local Banking (micro) to keep capital in the
  community and bring in remissions and development
  loans
• Commerce based on internet trade with WTO
• Local ownership or regulation with cooperative
  marketing.
• Local radio broadcasting.

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Education and Health Care

• Educational computer supplement to Classrooms.
• Adult education in literacy and local economic
  issues.
• Local Teacher Education
• Online textbook distribution and local printing.
• Local addition of culture to courses with
  enrichment of cultural values.
• Distribution of local supplements Wikipedia
• Training health workers and linking with field
  hospitals

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Prof. Kaili Kan

• Dr. Kaili Kan is currently dean of the School of
  Business Management at Beijing University of
  Posts Telecommunications (BUPT). For over a
  decade, Dr. Kan was in charge of the research,
  recommendation and formulation of Chinas
  telecommunications policy and development
  strategies for the Ministry of Posts
  Telecommunications (MPT) and later the Ministry
  of Information Industries (MII). Dr. Kan received
  his Ph.D. from Stanford University in 1984. Since
  then, he also served in many posts
  internationally in the telecommunication sector,
  including Pacific Bell, ChinaSat, the World Bank,
  as well as operating a consulting agency in the
  US. Dr. Kans current interest is focused on the
  research and development of Chinas
  telecommunication policy and strategies and can
  be reached at kailikan_at_yahoo.com.

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VoIP Driving the Restructuring of
Telecommunications

• Prof. Kaili Kan
• Beijing Univ. of Posts Telecommunications
• ITU Future of Voice Workshop
• Geneva Jan. 16, 2007

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Is VoIP Killing Telecom ?

• Telcos claim
• VoIP is IT invading telecom
• VoIP robs voice revenue from telcos
• VoIP takes a free ride of telcos hard-built
  network infrastructure
• The Martians are coming !
• Telecom sector in turmoil WHY ?

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Current Structure of Telecom

• Vertical integration (OSI 7 layers)
• Network Service
• History background
• Shortage of bandwidth
• Single servicevoice
• However, time has changed.

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Surplus Optical Bandwidth

• Bandwidth telcos core product
• Cost of bandwidth
• Infinite bandwidth over fiber
• Cost approaches zero cross-Atlantic lt
  USD0.0001/min. (ITU 1996)
• Price of bandwidth
• Redundancy Each telco builds its own fiber
  cables for vertical integration
• Price to be driven to zero even faster than cost

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The Killer

• Law of Economics
• oversupply kills supplier
• Telcos killed themselves by oversupplying
  bandwidth
• Why blame it on VoIP ? Nothing to do with VoIP,
  except

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Telcos Options for Survival

• Option 1 Break network service vertical
  integration
• Build less, use more open cable capacity to
  service providers
• Telcos become hollow pipes
• Option 2 Insist on network service vertical
  integration squeeze revenue/profit out of
  inefficient usage of bandwidth,
• Fact many telcos chose Option 2.

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Conditions for Price-Discrimination

• Shortage of supply
• True before copper, 1G, 2G, etc.
• NOT true now fiber, 3G, Wi-Fi/ WiMAX
• Insulation of markets no cross-border smuggling

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Role of VoIP

• Breaks insulation Smuggles voice into
  low-priced broadband market
• Eliminates price-discrimination of voice vs.
  data/video
• Forces telcos to go back to Option 1
• Service providers share telcos fiber cable
• Telcos become hollow pipes
• Vertical network-service integration broken
• However, with fiber cables already over-built,
  too late.

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Future of Telecom

• Internet/IP technology
• Independent of physical network
• Terminator of vertical integration by nature
• Vertical integration broken
• Networks bandwidth, access
• Services liberated
• Telcos
• Fixed network telcos degenerate into hollow
  pipes
• Mobile operators extinction (VoIP Wi-Fi/ WiMAX)

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Vision

• Internet Of the people, by the people, for the
  people
• VoIP restructuring telecom (a revolution)
• Breaking telcos network service vertical
  integration equals to convergence

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China at a Crossroad

• Background
• Telcos State Owned Enterprises (SOEs)
• National security issue
• VoIP situation
• Officially illegal nationwide
• 4 experiments by Telecom and Netcom in own
  territory since mid-2005
• Proliferation in underground / gray market
• VoIP deployment only a matter of time

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Thank You

• kankaili_at_gmail.com

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Comment

• Dr Kahn outlines the overbuild of fiber-optic
  cable networks by telephone corporations around
  the world.
• The excess capacity has been sold competitively
  to Internet suppliers.
• Internet now offers switching and voice service
  as well as data and TV through the low-cost world
  fiber.
• Voice Over Internet Protocol (VoIP) is breaking
  the monopoly the Telcos held and establishing
  very low real service costs.

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An Analysis ofMunicipal Wireless Broadband
Coverage (WBC) Models

• Prof. Kaili Kan
• School of Economics Management, BUPT
• kankaili_at_gmail.com
• CPRsouth Manila Jan.19, 2007

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Development of WBC

• Proliferating throughout the world over the last
  two years
• 40 cities by the end of 2005
• 400 cities by mid-2006
• Especially in Asia-Pacific region Singapore,
  Taiwan, etc.

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WBC Characters

• Goals
• Social development municipal infrastructure
  (5th Utility)
• Social welfare narrow the digital divide
• NOT for profit
• Driving force
• Municipal governments
• NOT telcos

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WBC Characters

• Goals
• Social development municipal infrastructure
  (5th Utility)
• Social welfare narrow the digital divide
• NOT for profit
• Driving force
• Municipal governments
• NOT telcos

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Analysis of Models (1)

• Financed, built and operated by municipalities
• Pros
• Best implements government goals (free-of-charge
  possible)
• Cons
• Burden for the government financial, operational
  and legal (equality of service?)
• No public participation
• No market mechanism
• Rigid planning lacks flexibility

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Analysis of Models (2)

• Financed, built and operated by private industry
• Pros
• No burden for government
• Market mechanism reacts quickly
• Cons
• Deviate from government goals for profit
• Potential spectrum shortage for full competition
• Need to regulate licensing, tariffing, universal
  service, etc.

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Analysis of Models (3)

• Financed, built and operated by government
  contracted private monopoly
• Pros
• Possible to implement government goals
• Cons
• Conflict between government and corporate goals
• Difficulties in regulating a monopoly
• Lack of market dynamics

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Analysis of Models (4)

• Financed, built and operated by grass-root
  communes
• Pros
• Mobilizes public participation
• Best serves social interest (free-of-charge
  possible)
• No burden for government
• Cons
• Hard to reach critical mass for rapid expansion

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The Internet Spirit

• Of the people,
• By the people,
• For the people.
• One for all, all for one.

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WBC Model Approach

• Municipal wireless broadband coverage
• Why do we need telcos?
• Why not by the people?
• Who is leader of the people?
• What is the role of the leader?

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WBC Model Approach

• Municipal wireless broadband coverage
• Why do we need telcos?
• Why not by the people?
• Who is leader of the people?
• What is the role of the leader?

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The Wireless Commune

• Led by the Government,
• Built by the People.
• Active leading role by municipal governments
• Active participation by the people
• Shared network resources
• Competition among telcos for connection

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Example Beijing Commune (1)

• Beijing government for police, traffic control,
  public areas, etc.
• 2,000-3,000 access points (APs)
• Wi-Fi (802.11g) 54 Mbps/AP
• Covers main streets and public areas
• One-time funding USD 2-3M
• For own usage (maintenance)
• Over capacity free access open to public
• Beijing Wireless Commune established

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Example Beijing Commune (2)

• Local entities (e.g., BUPT)
• Campus covered by Wi-Fi hotspots for own staff
  and students
• Open to non-BUPT users (commune members) in
  exchange of
• Free usage of commune APs
• BUPT becomes commune member
• Municipal WBC (commune APs) expands by members
  joining

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Example Beijing Commune (3)

• Individuals
• Set up own AP at home/office
• Open to members in exchange of
• Free usage of WBC (commune APs)
• Becomes commune member
• Municipal WBC further expands

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Example Beijing Commune (4)

• General public (non-members)
• Free access at controlled speed and lower
  priority at commune APs
• Becomes potential member by usage dependence
• Visitors free access for limited period
• Non-member usage (speed, priority, etc.) used as
  control for membership expansion (diminishes as
  WBC grows)

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Example Beijing Commune (5)

• Telcos
• Each member pay for own Internet connection via
  telecom operators
• Telcos compete for connection and maintenance
  businesses
• Telcos transformed into hollow pipes and
  maintenance service providers

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Advantages of Wireless Commune

• Best achieves social goals
• Least risk for governments (financial,
  operational, legal, political, etc.)
• Fast expansion (Beijing estimated to reach
  100,000 APs in 3-5 years)
• Telecom sector restructured
• New players municipal government, end-users
• Telcos being phased out

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Municipal Wireless Broadband CoverageChanging
the World
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Thank youStay in touch

• kankaili_at_gmail.com

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Comments

• Dr Kahn reviews a number of options for Municipal
  Wireland Broadband, MiFi and WiMax, to offer
  services.
• Municipal networks to interconnect government
  services as backbone then subscribed to by
  general public
• Local institutions (colleges etc) with added
  subscribers.
• Community action groups plus subscribers.
• All offer local service interconnected by
  Internet.
• Good model for our rural communications projects
• He makes the point that traditional Telcos are
  obsolete and very expensive
• Well see Telco barriers in rural projects.