THESIS PRESENTATION

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THESIS PRESENTATION

• Real Time Transport Protocol Processing in a
  Voice over IP Network

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SUPERVISORS

• Supervisor Sven-Gustav Häggman
• Instructor
• Tapio Savunen(Head of RD, Nokia Networks)

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FACTS ABOUT THESIS

• Work done in year 2001 (for Nokia Networks) with
  almost 6-8 months of full-time (and more) effort
• Thesis report completed in 2005

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FACTS ABOUT THESIS

• A VoIP prototype system implemented
• Workd done from implementation specifications to
  code development, module testing and successful
  demonstration of voice calls (individual and
  group).

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PROTOTYPE ARCHITECTURE

• Architecture consists of Control Plane server,
  User Plane server, and LAN client (simulating
  Nokia Mobile terminals.
• Specifications for interface between Terminal,
  Control plane server, User plane server have been
  finalized in advance

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PROTOTYPE ARCHITECTURE

• Desktop PCs used with Linux OS (RedHat) as
  control plane and user plane servers
• Laptop used as LAN client, with Wireless LAN in
  order to simulate air-interface feeling

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PROTOTYPE ARCHITECTURE

• SIP protocol used as interface between User
  Terminal and Control Plane server (and between
  Control Plane servers). SIP works with Control
  Plane (identify and manage calls by contexts)
• RTP protocol used as interface between User
  Terminal and User Plane server (and between User
  Plane servers). RTP works with User Plane
  (identify and manage calls by IP)

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PROTOTYPE ARCHITECTURE

• MEGACO protocol used as interface between Control
  Plane server and User Plane server
• IPv4 Network

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PROTOTYPE ARCHITECTURE
MS User Terminal U-UPF, G-UPF User Plane
Servers U-CPF, G-CPF Control Plane Servers
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POC CONCEPT

• POC is Push to Talk (PTT) over Cellular
• User must always press PTT (push-to-talk) button
  in order to talk
• This prototype demonstrates POC-like service
  using VoIP

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WHAT USER CAN DO WITH THIS PROTOTYPE?

• User(s) can login into system
• User can make individual call to another user
• User can make group call

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WHAT USERS CAN DO WITH THIS PROTOTYPE?

• User(s) can join to a predefined Talk-Group
• User can talk/listen in a Talk-Group
• User can log-off

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USE CASE USER LOGIN

• MS sends SIP message to Control Plane with
  terminal information
• Control Plane does basic checkings, remembers
  this data and sends MEGACO message to User Plane
• User Plane memorizes terminal information and
  sends MEGACO reply to Control Plane
• Control Plane sends SIP message back to MS
  informing successful login (if so!)

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USE CASE INDIVIDUAL CALL

• MS (caller) sends RTP call setup (with callee
  info) message to User Plane
• User Plane does necessary checking and informs
  control plane (MEGACO)
• Callers Control plane contacts Callees Control
  plane (SIP) to find if callee is able to accept
  call

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USE CASE INDIVIDUAL CALL

• After positive acknowledgment, Callers control
  plane informs Callers User-plane (MEGACO)
• Caller user-plane sends RTP (positive
  acknowledgement) to MS
• MS can now press PTT and start sending audio

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THESIS WORK

• There are 31 Use-cases implemented in this
  prototype
• Actual Thesis Work Implementing these 31
  Use-cases for USER PLANE server (in addition to
  specifying such use cases testing bug-fixing
  demonstration)

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THESIS WORK

• Other teams were involved in developing
  counter-part use-cases for Control Plane server,
  MS (LAN client)
• MS Word used for documentation
• Linux, C, C, GNU Tools for SW development

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WORK CONTINUES...

• This prototype served as first proof of concept
  to demonstrate POC-like service using VoIP
• Full scale network is now running in some of
  major Mobile Operators worldwide who now provide
  PoC sevice to consumers

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THANK YOU