Telecommunications Basics in ZA

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Telecommunications Basics in ZA

• International Standards
• The Existing Networks in ZA
• Telkoms PMA packet mode architecture
• Politics and Money who owns whom
• Telkoms IPO listed at R28, now around R42.
• Deregulation SNO and TNO
• Some key current issues

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International Standards

• European Telecommunications Standards Institute
  (ETSI) defines Synchronous Digital Hierarchy. SDH
  tells us how to frame and carry 2Mb / 34Mb /
  140Mb digital streams over fiber with basic
  transmission rate of 155.52Mb.
• American National Standards Institute (ANSI)
  defines SONET Synchronous Optical Network
  standards, which carries T11.5Mb / 2.0Mb/ 6Mb /
  T345Mb streams on fiber with transmission based
  on 51.84Mb units.

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Other standards bodies

• ITU - International Telecommunications Union

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In ZA

• We use mainly European standards they are our
  major trading partners. (PAL TV, GSM, 240 volt
  power)
• 2Mb (E1) is our basic logical building block in
  our telecomms
• Siemens (Germany) and Alcatel (France) have been
  two preferred suppliers for Telkom network.
  Both have big return investment in ZA. The
  Alcatel hardware manufacturing plant in Boksburg
  was a world-class facility, but closed about 2
  years ago after Telkom cut capital expenditure.

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A fixed-line network logical view

• Access network customer to the local exchange.
• Core network long distance transmission and
  switching
• In USA, when Bell was broken up, operators were
  not allowed to have interests in both market
  segments. So the Local Exchange Centers (LECs)
  are separate companies from the long distance
  operators like Sprint, Bell, etc.
• A LEC runs the access network, with a local
  exchange, and little white vans with ladders on
  the roof.

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The Access Network

• Access network has vast copper infrastructure.
  Recently concerned with technologies like
• DECT last-hop radio transmitters,
• ADSL squeezing fast access speeds from existing
  copper,
• Line-of-sight infrared transmitters,
• Carrying signals on galvanized farm fence wire,
• Spread Spectrum radio technologies over short
  distances,
• Carrying data on electricity power lines,
• Low Earth Orbiting Satellite systems for local
  access.
• Youll often hear the term The last mile.
• It is the really tough bit and half the cost of
  a network!

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The Core Network

• Traditionally split into two functions. These
  are separate divisions within Telkom.
• Switching. How do we get the call set up, and
  send the data to the right place?
• Transmission. All the long-haul fiber optics,
  microwaves, undersea cables, etc.
• The network is reliable. Most of this comes from
  redundancy i.e. two of everything. This is
  not cheap.

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Similar dual-ring redundancy in SDH plant in ZA
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SDH / SONET recovery
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Signalling is on a separate network

• ITU Standard for signalling is SS7
• Signalling runs between Service Switching Points
  (SSP) processors which then control the
  switches.
• Now we prefer to separate controller and switch
  using a protocol like MGCP, so they need not live
  together.
• TCP/IP doesnt have separate signalling paths
• It drops packets as their main signalling
  mechanism!
• In-band signalling (current loop on old
  telephones) is slower, and is open to fraud.
  (Flanagan signalling tut pg 8)

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Our network is based on STM (Synchronous
Transfer Mode)

• This is an established (i.e. older) technology.
• STM defines how 30 voice calls are put into a 2Mb
  data stream. (e.g. Rhodes PABX does this.)
• Recall that a 2Mb stream is the basic E1 speed,
  the building block for switching and
  transmission.
• The switches accept multiple incoming E1 streams
  and switch calls into multiple outgoing E1
  streams.
• Everything is synchronous.

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How voice calls work in STM

• Voice is sampled at 8000 x 8-bit samples per sec
  64Kb
• 8000 frames, each 32 bytes, are sent per second.
  
• (8000 x 32) bytes per second is one 2Mb E1
  stream.
• Each voice call only gets to use one byte per
  frame.
• So a single E1, which can be carried on a copper
  pair, has 32 call slots. 2 are used for
  protocol overheads,
• We carry 30 voice calls in each E1 stream.
  Rhodes PABX has (had?) one copper pair to Huntley
  Street exchange, and could have 30 calls in
  progress at any time.

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How does the switching work?

• Circuit switched exchanges pre-allocate the
  frame slots during call setup, and the circuit
  remains allocated for call duration.
• So an exchange can switch traffic very
  efficiently.
• No buffering is needed in switches.
• Data is fixed size, regular, it stays in
  sequence.
• Problems
• Bandwidth is reserved whether you use it or not.
• Very inefficient for bursty, non-voice traffic.

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The switching
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For data streams across STM

• A 64Kb ISDN line just uses one slot per frame.
• A 384Kb ISDN connection would get allocated 6
  slots in every frame.

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The Transmission

• Microwave connections commonly carry 1920 or 7680
  voice calls.
• 128 Mbit , or 512 Mbit

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The Transmission on SDH

• We dont really use microwave for voice much now,
  
• But the same principles of multiplexing apply
  we have to combine the basic E1 2-Mb streams into
  bigger transmission speeds that will carry over
  our current fiber-based SDH network.
• A huge cost involves equipment that simply
  packages the data for transmission and unpacks
  it at the other end.
• Youll hear lots about add/drop multiplexors
  (muxes) that can add or extract slower data
  streams without unpacking and rebuilding the fast
  stream.

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Spectacular advances in Physics

• 1966 Experiments show that eliminating impurities
  from glass will minimize light loss. First time
  we realized glass could be used to carry data.
• 1967 Losses are 1000 dB/Km - (12 meters could
  work)
• 1970 Losses are 20 dB/Km - (600 meters could
  work)
• 1976 Losses are 0.5 dB/Km - (24Km)
• 1979 Losses are 0.2 dB/Km - (60Km)
• 1987 Losses are 0.16 dB/Km - (75Km)
• 1988 - 10Gb/sec (150 000 voice calls) over 80Km.

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Even more optics advances

• ITU-T set standard for 24 colour (lambda)
  division multiplexing.
• But 80 lambdas now seen in Dense Wave Division
  Multiplexing (DWDM). It allows upgraded
  bandwidth by just improving equipment on the
  edges.
• Installed fiber plant delivering much more
  bandwidth than was catered for in original
  business models.
• Light amplifiers need no power can position
  amplifier about 2/3 of way on fiber, and inject
  extra light source used to amplify from short
  end. Usable fiber spans well in excess of
  100km.
• Company with DW Lambda technology (cross-connects
  and wavelength converters) snapped up by Nortel.
• Cross-connects are done slowly (e.g. in msecs)
  using mirror technology using electrostatic
  charges to distort substrate and position
  mirrors.

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Some optics research

• Broadband backbone demand tripling each year.
  (Bay News TV program). New company getting major
  backing for technology that somehow decentralizes
  fast central optical switching in favour of small
  cheaper switches and light packets that find
  their own way around.
• Glen Kramer (UC _at_ Davis) working on cheap passive
  component for tails in fiber-to-kerb solution
  1 GB fiber broadcast to 16 apartments, gives 64Mb
  per home. Downstream broadcast and filter,
  upstream TDM. Claims present bottleneck all in
  access net, backbones are awash with bandwidth.

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Techwatch

• A company with DW Lambda technology
  (cross-connects) snapped up by Nortel.
• Cross-connects are done slowly (e.g. in msecs)
  using mirror technology using electrostatic
  charges to distort substrate and position
  mirrors.
• New soliton waveguide / pulse generation
  technique solves dispersion problem, now getting
  8000Km on fiber without repeaters in labs.

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Microelectromechanical Systems (MEMS)
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TCP/IP networks

• Packet switched network, no circuits.
• Packets are variable size, can be big.
• Each packet has to carry its destination address.
• These stay with the packet.
• We need quite tricky routing. Routers have to
  understand the address, and provide buffering.
• Each packet routed independently of others in the
  stream.
• Packets may arrive out of order.
• Problems cannot predict delays, hopeless for
  traffic that needs guarantees of bandwidth and
  response time.

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We need control and monitoring

• Telkom has Network Operations Centre (NOC)
• The ITU defines some standards to help monitoring
  equipment talk to switches. (TMM is a standard).
• But switch manufacturers like to use their own
  tools.
• Telkom and Telcordia presently in court over
  contract to provide management software. One
  sticking point was getting Telcordia software
  talking to Alcatel and Siemens switches switch
  manufacturers dont want to give their management
  secrets to competitors

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Telkoms PMA

• Packet switching is much cheaper and more
  efficient, but TCP/IP has unreliable Quality of
  Service (QoS).
• Telkom announced Packet Mode Architechture (PMA)
  project.
• The Cisco core switches will use MPLS (more in
  later lecture) to try to provide the
  circuit-like QoS.

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Emerging ZA Telecomms Landscape

• Fixed-Line
• Telkom
• SNO Second National Operator
• TNO Third National Operator
• Mobile
• Vodacom
• MTN, owned mainly by M-Cell
• Cell-C
• International
• What is Sentechs role?

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Politics and Money

• Deregulated 7 May 2002, Telkom lose monopoly.
• ICASA is regulatory body.
• Recent government award of third mobile operator
  licence to Cell-C, (with damage to everyones
  reputation, confidential out of court
  settlement),
• Sept 2001 govt said two new fixed-line operators
  would be licenced. Surprised the market because
  they previously said just one more And they
  made other concessions which weakened the
  position of existing players

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The Telkom IPO

• M-Cell, who hold MTN, lost R6bn in market
  capitalization on the announcement of the extra
  TNO (share price loss x number of issued shares)
• Analysts said the Telkom IPO expectation was now
  only 50-60 of previous value, because of the
  extra TNO.
• Thintatu CEO Tom Barry (also Telkom CEO) warned
• We have contract to prevent you selling more than
  20 in an IPO.
• We can contribute half the IPO shares if we wish
  to.
• So perhaps well sell our 10. Govt can then
  only sell 10
• (my interpretation We dont like your
  announcement. IPO share price will dive if we
  sell our 10. We can wreck your privatization
  program. Reconsider, and give us a licence to
  print money!)

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• Less than 2 weeks after announcing the Third
  Network Operator, the Minister did an about turn
• But the damage was done.

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• 7 May 2002 Telkom is ready to compete as it
  shrugs off its monopoly mantle Today marks the
  end of Telkom's five-year exclusivity period, and
  the Company is ready to hold its own in a
  competitive market where South Africans will soon
  be able to choose their fixed-line communications
  supplier. "Telkom has spent the past five years
  preparing for this, and I am confident that we
  can stand on our own in the market. And it's not
  just we who are saying this - our shareholders
  and most of our customers are seeing a very
  different Telkom today from the Telkom of five
  years ago," said Telkom's CEO, Sizwe Nxasana.
  He added that Telkom was satisfied that it had
  achieved the turnaround it had been mandated by
  Government to do since 7 May 1997.

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The Telkom IPO

• Govt sold 30 of Telkom to Telcom Malaysia and
  Southwest Bell (SBC) about 5 years ago, for
  R5.6bn. Local umbrella company is Thintana.
• They planned to sell 20 more by Q1 of 2002 in a
  public IPO.
• They hoped to raise R14bn, needed to pay loans
  etc.
• BUT, dilly-dally policy initiatives and an
  unexpected 2002 announcement about two new
  competitors had a devastating effect

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Govt initially wanted R14bn for 20 - total
valuation R70bn Govt then said R10bn. Finally
it sold for R4bn. Did SA lose R10bn because of
gross political ineptitude? Listed at R28 in
March, now about R42 per share.
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Other Telkom-related issues

• Internetworking charges. Telkom withheld R34M
  from Vodacom in 2001. Of a R1.64
  cell-to-fixedline call, they were getting 21c.
  Reverse direction, they paid about R1.12 to the
  cell operators. They managed to force the
  regulator to review the contract. Details are
  now confidential.
• They introduced a pilot 1007 service for own
  staff the prefix routes calls into their
  international VOIP network, to the UK, then back
  to SA and then to the cell network. The UK to
  SA-Cell agreement is much more favourable to
  Telkom. This was a veiled threat to the
  regulator and the cell operators.

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ISPs fight Telkom

• ISPs are offering VOIP, undercutting Telkoms
  income.
• It is probably illegal. Within one organization
  and between different organizations have
  different regulations.
• Exactly what constitutes a value added service
  is vague.
• Telkom respond by refusing to deploy extra
  bandwidth for ISP growth.
• The regulator is out to lunch on this (my
  opinion)

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Some other hot spots

• Tariff rebalancing vs low-cost local calls.
• Role of wireless. What does the Sept 2001
  announcement really mean? What about PDAs? Car
  navigation systems? Seems like wireless
  protection for cell operators may be strictly
  only for cellphones. ICASA have not been willing
  to clarify.
• Threat of competition only entering jewel
  markets. How do we fix social concerns for
  universal access?

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• Feb 07 2003 Icasa may challenge minister on phone
  bid As Goldleaf withdraws its legal action and
  will instead submit a fresh bid.
• THE Independent Communications Authority of SA
  (Icasa) is examining whether to challenge
  government over concerns that its powers may have
  been usurped by a new bidding process ...
• Feb 21 2003 Matsepe-Casaburri outlines thinking
  on new process Committee to be formed under
  chairmanship of communications deputy
  director-general Pakamile Pongwana. FOR the
  first time, Communications Minister Ivy
  Matsepe-Casaburri has detailed government's
  rationale in establishing a new process... March
  03 Phone bid still on hold as talks delayed
  THERE is growing uncertainty about the ability
  of government to fast-track the second phone
  operator licence amid opposition from the
  regulator, with one key deadline having already
  been missed.... June 19 2003 Minister places the
  ball firmly in Icasa's court This time, the
  bidding process for a majority stake in a second
  operator has been swift and smooth Editor at
  Large WITH her acceptance of two recommended bids
  for a 51 stake in the planned second national
  telephone operator, Communications Minister...

All from Business Day site
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