GENERIC ACCESS NETWORK

1
Chapter 5

• GENERIC ACCESS NETWORK
• TOWARD FIXEDMOBILE
• CONVERGENCE

2

• Unlicensed Mobile Access (UMA) is different from
  other technologies that deliver voice and data
  over IP/Wi-Fi.
• Offering a completely seamless service to the end
  user as he moves between the macro Global System
  for Mobile (GSM) access network and Generic
  Access Network (GAN).
• GAN is part of 3GPP R6 standards.

3
Section 5.1

• TRENDS IN THE INDUSTRY

4
5.1 TRENDS IN THE INDUSTRY

• UMA allows operators to deliver GSM/General
  Packet Radio Service (GPRS) services over a fixed
  broadband network to a dual-mode Wi-Fi handset in
  a completely seamless manner.
• Mobile and broadband networks also show
  drawbacks
• Difficult for the normal GSM network to provide
  good enough coverage using limited, licensed
  spectrum.

5
Section 5.2

• STANDARDIZATION

6
5.2 STANDARDIZATION

• How to deliver a GSM service over an IP
  connection?
• How to spread out GSM coverage into homes without
  investing in spectrum licenses and expensive and
  work-intensive base station installations?
• The user has the same number and same service
  when roaming between public radio access and
  Wi-Fi network
• The specifications have since been adopted by
  3GPP.

7
Section 5.3

• GAN OVERVIEW

8
5.3 GAN OVERVIEW
????"Technologies for Home Networking". Edited by
Sudhir Dixit and Ramjee Prasad, published by John
Wiley, 2008.
9
5.3 GAN OVERVIEW

• Moving between these three access networks,
  should
• Remain connected to the same mobile core network
• Enjoy the same services be reachable on the same
  number, and so forth
• Experience no break in service when moving
  between a GAN coverage area and, for example,
  GERAN

10
5.3 GAN OVERVIEW
????"Technologies for Home Networking". Edited by
Sudhir Dixit and Ramjee Prasad, published by John
Wiley, 2008.
11
5.3.1 Security

• Based on the security mechanisms defined for the
  3GPP Interworking WLAN IP Access scenario.
• IKEv2 , EAP/SIM, EAP-AKA
• All defined in Internet Engineering Task Force
  (IETF) specifications.

12
5.3.2 Discovery and Registration

• Used to allocate the best possible GANC for the
  handset in the current location.
• Discovery
• Used between the handset and the Provisioning
  GANC, which is the initial point-of-contact in
  the GAN.
• Provisioning GANC is to allow access to the GAN
  and allocate a Default GANC to each mobile
  station (MS), which is main point-to-contact for
  handset in GAN.

13
5.3.2 Discovery and Registration

• Handset tries to access GAN from a new location,
  it will initiate Registration to the Default
  GANC.
• When registration is accepted, the Serving GANC
  returns the GAN System Information to the
  handset.
• Serving GANC connect to the Mobile-services
  Switching Center (MSC) , support handovers
  between the GAN and the macronetwork.

14
5.3.3 Rove In and Rove Out

• Used in the GAN standard for roaming between the
  WLAN coverage and GERAN/UTRAN.
• Rove in means the handset starts communicating
  actively using the protocols in the Up interface
  and these protocols start serving the upper
  layers in the Handset.
• Rove out means the handset stops communicating
  using the protocols in the Up interface and the
  relevant GERAN/UTRAN protocols are used instead
  and serve also the upper layers in the Handset.

15
5.3.4 Transparent Access to Services in the
Mobile Core Network

• The Up interface protocols provide transparent
  support for services in the mobile core network.
• This is achieved by tunneling all the upper-layer
  messages, like mobility management, SMS, call
  controletc
• Over the Up interface and then interworking these
  to the existing mechanisms in the A and Gb
  interfaces.

16
5.3.5 GPRS Support in GAN

• The Up interface also supports transport of GPRS
  control signaling and user plane traffic using
  specific procedures.
• Allow the network to support a very large number
  of handsets.
• No need to keep handset-specific data in the GPRS
  part of GANC for idle handsets.

17
5.3.6 Location Services

• Handset indicates to the GANC the current camped
  GERAN or UTRAN cell.
• Handset includes the MAC address of the WLAN AP
  being used, and the GANC can use an external
  database to map these to an exact geographic
  location of the AP.

18
5.3.7 Emergency Services

• Placed over GERAN/UTRAN or over GAN.
• Over GERAN/UTRAN existing location determination
  services are used
• Over GAN Location determination mechanisms are
  used to guide the core network in routing to the
  right Public Safety Answering Point (PSAP)

19
5.3.8 GAN Protocol Architecture

• Generic Access Circuit Switched Resources
  (GA-CSR)
• Mobility management (MM)
• Base Station System Application Part (BSSAP)
• Message Transfer Part (MTP)
• Signaling Connection Control Part (SCCP)
• Direct Transfer Application Part (DTAP)

20
5.3.8 GAN Protocol Architecture
????"Technologies for Home Networking". Edited by
Sudhir Dixit and Ramjee Prasad, published by John
Wiley, 2008.
21
5.3.9 Bluetooth or Wi-Fi?

• Particularly with Wi-Fi equipped handsets
• There seems to be consensus that Wi-Fi will
  prevail.
• GAN is an opportunity to offer a voice service
  over local WLAN networks with good coverage while
  ensuring that the traffic remains controlled in
  their core networks.

22
Section 5.4

• BENEFITS WITH THE GAN TECHNOLOGY

23
5.4 BENEFITS WITH THE GAN TECHNOLOGY

• No radio license is required, because GAN
  operates in the license-free spectrum.
• No radio planning is required. Current
  license-free technologies such as Bluetooth and
  IEEE 802.11 are self-planning.
• Range is limited compared with the macro
  technologies of GERAN and UTRAN. Typically, one
  can expect 2030 m indoors and up to 100 m
  outdoors or larger indoor spaces.

24
5.4 BENEFITS WITH THE GAN TECHNOLOGY

• GAN utilizes WLAN access points that are either
  already in place or set up for the purpose. These
  are typically around the 50100 USD price point,
  or even lower.
• GAN uses IP as its bearer service It may be
  delivered over DSL, cable, Ethernet, or other
  networks already in place to homes and offices.

25
5.4.1 Operators

• Deploy mobile voice services over the broadband
  networks that are now becoming broadly deployed.
• With GAN, a converged end-user offering can be
  constructed that both leverages mobile telephony
  and broadband.

26
5.4.2 End User

• If typical market mechanisms prevail, some of
  these benefits will be passed on to the end user.
• With GAN, the end user experience remains the
  same in the WLAN domain as in the wide area radio
  domain.
• End user has one phone with one number
  independently of access method and location
• The end user experiences functionality
  transparency (same services independently of
  network) and seamless mobility between the two
  domains with roaming and handover in both
  directions.

27
5.4.3 Terminal Availability

• Standardization is a key element while
  introducing new protocols into the handsets as
  this guarantees interoperability between the
  handsets and the infrastructure.
• Terminal and network vendors have taken an active
  part in the 3GPP GAN standardization process.
• The standard minimizes the impact on the terminal
  and leverages on already existing implementations
  in the handsets.

28
Section 5.5

• PRACTICAL EXPERIENCES

29
5.5 PRACTICAL EXPERIENCES

• Setting up the service, plugging in the access
  point, registering the handset, and so forth, are
  usually straightforward, a plug and play
  experience.
• Coverage, even with early pre-UMA handsets with
  low-power Bluetooth radio,is sufficient for
  residential uses and comparable with normal
  cordless phones.
• Service and user experience is indistinguishable
  from what is found via the macronetwork, except
  for battery life, which with some early
  implementations was significantly lower with UMA
  enabled.

30
Section 5.6

• IMPACT ON NETWORKS AND PROCESSES

31
5.6 IMPACT ON NETWORKS AND PROCESSES

• Operators will probably need to change certain
  configuration data in order to facilitate. (e.g.,
  Handover between GAN and GERAN.)
• The key components of the GAN itself need to be
  installed (e.g., the GANC, the security gateway,
  etc)
• GANC is largely going to appear as just another
  BSC. This impact is probably going to be modest
  compared with the work involved in launching a
  completely new type of service.

32
Section 5.7

• DISCUSSION

33
5.7 DISCUSSION

• Voice over WLAN protocols do not deliver the
  same transparency, as they rely on the user being
  served by a different core network when in
  WLAN-mode.
• On the business side, GAN offers many compelling
  features
• Allows broadband operators to combat
  fixed-to-mobile substitution by offering a
  full-spec mobile service to their customer base.

34
Section 5.8

• EVOLUTION OF GAN

35
5.8 EVOLUTION OF GAN

• IMS is a core network evolution that will offer
  current voice and data services, as well as new
  combinations of these, through different access
  networks.
• IMS is an evolution of the core and service
  layers, whereas UMA is an evolution of the mobile
  access network.
• Evolution to 3G is another topic often discussed
  in relation to GAN.

36
Section 5.9

• CONCLUSIONS

37
5.9 CONCLUSIONS

• GAN is backed by a number of dominant handset and
  system providers on the market.
• This technology is proved to work and the
  protocols are standardized, there are no
  technical barriers for success.