3G and Beyond

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3G and Beyond
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Integration of voice and data traffic

• Multimedia applications require both voice and
  data.
• The main feature of 3G cell phone systems is to
  handle both voice and data so users can access
  the Internet and e-mail, listen to music, watch
  movies, use navigation, etc.
• Data oriented systems, e.g., 802.11 need to
  handle voice, too, due to the use of Voice over
  IP.

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Drawbacks of voice oriented systemsunused
capacity

• In TDMA/FDMA, a number of channels are assigned
  to a cell. When the number of active users falls
  below the available number of channels, some
  portion of the available capacity is not used.
• Speech appears in spurts, and two parties dont
  speak simultaneously. A typical two-way
  conversation only use 40 of the connection time.
  

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Drawbacks of data networks

• Quality of Service is not guaranteed. Data are
  transmitted in packets. There can be delays and
  interruptions, which are not tolerated in voice
  transmission

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Evolution of cellular systems (2G)

• 2G
• GSM European TDMA
• D-AMPS (Digital-Advanced Mobile Phone System)
  IS-54 and IS-136 which are TDMA standards used in
  the US and have been replaced by GSM or TDMA2000.
• IS-95 IS-95/cdmaOne, CDMA in the US

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Evolution of cellular systems (2.5G)

• 2.5G
• GPRS (General Packet Radio Service)
• To transmit and receive TCP/IP based data to and
  from GPRS mobile devices
• HSCSD High-speed circuit-switched data, which is
  a part of EDGE and UMTS

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Evolution of cellular systems (2.75G)

• CDMA2000, 3G standard in the US
• EDGE (Enhanced Data for Global Evolution) is a
  method to increase the data rates by introducing
  a new modulation technique and channel coding,
  and thus an add-on to GPRS. EDGE can transmit
  three times as many bits as GPRS during the same
  period of time.
• It uses phase modulation. With 8 phase shift,
  three consecutive bits are mapped onto one
  symbol. Thus the data rate increases 3 times.

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Comparison GPRS and EDGE

• GPRS EDGE
• Symbol rate 270 ksym/s 270 ksym/s
• Modulation bit rate 270 kb/s 810 kb/s
• data rate/time slot 20 kb/s 59,2 kb/s
• data rate/8 time slots 160 kb/s 473,6 kb/s

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Evolution of cellular systems (3G)

• W-CDMA, European 3G
• 1xEV-DO (1xEvolution-Data Optimized)/IS-856,
  developed by Qualcomm in 1999 to meet IMT-2000
  requirements. US 3G provided by Sprint and
  Verizon. Download speed 2.5-3 Mbps.
• TD-SCDMA (Time Division-Synchronous CDMA),
  Chinese 3G

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Evolution of TDMA
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GPRS (General Packet Radio Service)

• Based on GSM
• GPRS does not require permanently allocated
  physical channels (frequencies and time slots).

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GPRS (contd.)

• Phase 2 (2.5G)
• It provides an "always on", high-speed connection
  (up to 171 kbps in theory, typical 56 kbps) to
  packet data networks, which is suited to the
  "bursty" traffic on the Internet and World Wide
  Web, either directly or via operators' portals.
• With GPRS, the core network is enhanced to
  embrace the packet switched domain, adding new
  IP-connected network elements. Crucially, this
  extension lays the foundations of a common core
  network for 2G and 3G.

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EDGE (Enhanced Data rates for GSM Evolution)

• EDGE further enhances GSM/GPRS radio interface by
  adopting new modulation technology to achieve
  higher data rates (180 kbps) using existing GSM
  radio spectrum.
• EDGE is the other pre-3G radio access technology
  directly evolved from GSM. It includes advanced
  Quality of Service mechanisms,
• Limited data rates compared with WCDMA/TD-SCDMA.
  Used to provide 3G services in existing 2G
  spectrum resources.
• WCDMA and TD-SCDMA will not necessarily replace
  GPRS or EDGE, but will in reality co-exist with
  them, and can share one common core network.

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UMTS

• UMTS introduces WCDMA for paired bands (5MHz
  each), as well as TD-SCDMA and TD-CDMA for
  unpaired bands.
• to support High Speed Downlink and Uplink Packet
  Access (HSDPA, sometimes called 3.5G), enabling
  transmission at speeds of up to 14.2 Mbit/s.
• IP Multimedia Subsystem (IMS). It enables
  real-time, person-to-person services, such as
  voice or video telephony, to be provided by means
  of packet switched technology in common with
  non-real-time information and data services.

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UMTS (contd.)

• The ability to work with other networks such as
  Digital Video Broadcasting (DVB) and Digital
  Audio Broadcasting (DAB)
• To take advantage of the content offerings that
  can be delivered efficiently to phones.

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3GPP (Third Generation Partnership Project)

• Established in December 1998
• Represents 437 operators and vendors worldwide.
  It brings together a number of telecommunications
  standards bodies, currently ARIB and TTC (Japan),
  CCSA (China), ETSI (Europe), T1 (USA) and TTA
  (Korea).
• to produce globally applicable Technical
  Specifications and Technical Reports based on
  GSM, FDD and TDD.
• Include GPRS and EDGE.
• Standardize WCDMA and CDMA/TD

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GAN/UMA (Generic Access Network/Unlicensed Mobile
Access)

• Allowing seamless roaming and handover between
  Wi-Fi network and cellular networks
• Advantages
• Cheap way to expand coverage
• Relieves congestion on the cellular spectrum by
  using relatively low cost Internet
• Particularly good for operators that also offer
  Internet services. Can promote both cellular and
  Internet services
• Improve receiving condition at homes

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The future
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CDMA-2000 family

• EV-DV (Evolution-Data and Voice) EV-DV standard
  was less attractive to operators, and has not
  been implemented.
• EV-DO (Evolution-Data Optimized) It is
  standardized by 3rd Generation Partnership
  Project 2 (3GPP2) as part of the CDMA2000 family
  of standards. Data speed can reach 2.4 Mbit/s
  with Rev. 0 and up to 3.1 Mbit/s with Rev. A.