Multimedia%20Broadcast%20/%20Multicast%20Service%20from%20GERAN%20Physical%20Layer%20Point%20of%20View

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Multimedia Broadcast / Multicast Service from
GERAN Physical Layer Point of View
Thesis Work Presentation 17.01.2006

• Henri Virta
• Supervisor Prof. Sven-Gustav Häggman
• Instructor M.Sc. Toni Majuri

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Contents

• Background
• Objectives Methodology
• Introduction to MBMS
• Competing technologies
• MBMS from PH Reselection point of view
• Summary and conclusions

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Background information

• Multimedia Broadcast Multicast Service (MBMS) is
  a new feature specified in 3GPP Release-6
• Method of delivering the same multimedia contents
  to several recipients in the service area
• Main idea behind the MBMS development is to
  provide multimedia contents simultaneously to
  several users, while preserving the network and
  radio resources

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Objectives Methodology

• Objectives
• Introduce the MBMS service
• Compare the MBMS service to other available
  solutions
• Analyze the MBMS service from GERAN/Physical
  Layer and specifically from PH reselection point
  of view
• Methodology
• Literary study based on 3GPP and ETSI
  specifications and change requests
• MBMS related conference papers and research
  articles
• Discussions within the Nokia organization on MBMS
  related issues

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Introduction to MBMS (1/2)

• The main idea behind broadcast/multicast services
  is the possibility to save resources in the radio
  and core networks, by sharing the transmission
  path
• All MBMS services can be provided with cellular
  point-to-point (P-t-P) connections, but MBMS is
  more efficient if the same contents is delivered
  to several recipients in the same area
• The MBMS service is a solution for transmitting
  light video and audio clips, although it can also
  be used for real time streaming videos as well

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Introduction to MBMS (2/2)

• MBMS bearer service offers two modes
• Broadcast Mode
• All users in the broadcast area can receive the
  broadcast service
• Multicast Mode
• Only users who have subscribed to the specific
  multicast service and have joined the multicast
  group can receive the multicast service
• The subscribers can receive services, such as
  streaming video in a more economical manner.
• The Operator will control the MBMS service and
  content and can also control the QoS for the MBMS
  services
• For the Operator, MBMS will allow more efficient
  delivery and flexible pricing of existing
  point-to-point multimedia services

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MBMS Procedures
Multicast mode
Broadcast mode
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MBMS architecture

• MBMS architecture is designed so that the
  existing network elements could be re-used as
  efficiently as possible.
• A new component Broadcast/Multicast Service
  Center (BM-SC) is needed in Core Network
• BM-SC serves as an entry point to content
  providers and is responsible for enabling the
  MBMS services to be provided to the end users via
  the Core and GERAN / UTRAN networks.

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MBMS User Services

• The underlying MBMS technology is transparent to
  the end-user
• MBMS is planned for Low-to-Medium bit rate
  multimedia services in areas where several users
  are receiving the same service
• 3GPP specifies three different service types
• Streaming includes time synchronization
• File download high reliability is required
• Carousel a combination of streaming and file
  download. Typical carousel service uses still
  images and text that are updated periodically.

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Other available solutions

• DVB-H (Digital Video Broadcast Handheld)
• High bit rate multimedia services
• Efficient wide-area delivery
• No uplink access and other arrangements are
  needed
• 3G Point-to-Point Connections
• Low-to-high bit rate multimedia services
• Efficient only when delivering content to a few
  individual recipients in a geographical area
• Uplink easily accessible
• CBS (Cell Broadcast Service)
• Kind of a pioneer in mobile broadcast services
• Low bit rate messaging (SMS service)
• Uplink easily accessible

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Comparison to 3G P-t-P connection

• MBMS advantage over traditional P-t-P connections
  is clear when there are several recipients of the
  same multimedia data
• Resources can be spared in the Core Network as
  well as in the Radio Interface
• The advantage of the MBMS bearer service is
  greatest if several users are receiving the same
  service at the same time

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Comparison to DVB-H

• DVB-H provides digital television to mobile
  handsets
• DVB-H is a solution to provide DVB-T(errestrial)
  programs to mobile users. The programs are sent
  to the mobiles in bursts by using IP data
  casting.
• Time slicing technique is used to achieve better
  battery saving percentage
• MPE-FEC error correction mechanism for additional
  robustness and mobility
• More efficient for delivering high bit rate
  multimedia services to wide areas, however uplink
  access not available
• MBMS has a possibility to limit transmissions
  only to areas populated by recipients
• DVB-H pilot programs already in use

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MBMS Service Positioning

• Bearers competing with MBMS
• 3G Point-to-Point bearers
• DVB-H multicasting
• MBMS vs. 3G Point-to-Point competition in
  sharing-type services
• MBMS vs. DVB-H competition in publishing-type
  services
• What is the overall feasibility of the MBMS
  service?
• What are the boundaries between competing
  bearers?

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MBMS from Reselection point of view (1/2)

• MBMS NEIGHBOURING CELL INFORMATION
• During MBMS the network may send MNCI messages,
  containing information about the neighbouring
  cells that are providing the same MBMS session.
• Delayed Reselection During MBMS
• If the mobile has not received the correct MNCI,
  the reselection is delayed for 1 second or until
  the correct MNCI is received
• Neighbour cell measurements
• If feedback is in use the mobile needs to report
  6 strongest neighbour cells to the network in
  MBMS Ack/Nack message

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MBMS from Reselection point of view (2/2)

• Reselection without the neighbour cell
  information
• The MS must first camp to the new cells control
  channels
• The MBMS service can be requested again from the
  new cell
• Fast reception resumption
• The MS moves directly to the new cells traffic
  channel (PDTCH) and continues to receive the MBMS
  session there.
• While receiving the MBMS session, the camping
  procedure is completed in the new cell by
  receiving the required (P)SI messages.
• SI2n
• A new system information message introduced in
  3GPP Rel-6
• Contains the necessary reselection parameters for
  the neighbour cells
• MBMS data transfer does not need to be
  interrupted for neighbour cell (P)SI reception

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MBMS delayed reselection scheme

• A simplified flow chart of the delayed
  reselection scheme

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Summary and Conclusions

• MBMS is a new bearer service that provides an
  efficient way of transmitting multimedia
  information to several users simultaneously
• MBMS is most efficient when several users are
  receiving the same service at the same time in a
  localized area
• MBMS will be competing with 3G P-t-P and DVB-H
  connections
• From reselection point of view, a big challenge
  will be the Fast reception resumption feature,
  since it changes the reselection and camping
  procedure
• Future Work
• Further studies and analysis of the MBMS
  features, before starting any design or
  implementation for MBMS

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Thank you!
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Additional information

• 3GPP Specifications on MBMS
• TS 22.146 Multimedia Broadcast/Multicast Service
  (MBMS)
• TS 22.246 Multimedia Broadcast/Multicast Service
  (MBMS) user services
• TS 23.246 MBMS Architecture and functional
  description
• TS 26.346 MBMS Protocols and codecs
• TS 43.246 Multimedia Broadcast Multicast Service
  (MBMS) in the GERAN
• Other useful 3GPP Specification
• 3GPP TS 45.008, Radio Access Network Radio
  subsystem link control (Release 6)
• 3GPP TS 44.060 General Packet Radio Service
  (GPRS) Mobile Station (MS) Base Station System
  (BSS) interface, Radio Link Control/Medium Access
  Control (RLC/MAC) protocol (Release 6)
• This material is available from the 3GPP
  homepage www.3gpp.org

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Backup information

• The MBMS service is analyzed from the Physical
  Layer (PH) point of view presented on the right
  hand side of the figure below