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SEMINAR REPORT ON GENERIC ACCESS NETWORK (GAN) By: Karan Kukreja 109/B.Tech(CSE)/ASET/2005 Submitted for: PARTIAL FULFILLMENT OF THE AWARD OF THE DEGREE OF B.TECH. (CSE) Under the Guidance of: Mr. Amrit Nath Thulal DEPARTMENT OF INFORMATION TECHNOLOGY, AMITY SCHOOL OF ENGINEERING AND TECHNOLOGY [AFFILIATED TO G.G.S.I.P.UNIVERSITY] OCTOBER, 2008
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Page 1: Seminar Report Generic Access Network Gan

SEMINAR REPORT

ON

GENERIC ACCESS NETWORK

(GAN)

By:

Karan Kukreja

109/B.Tech(CSE)/ASET/2005

Submitted for:

PARTIAL FULFILLMENT OF THE AWARD OF THE DEGREE OF

B.TECH. (CSE)

Under the Guidance of:

Mr. Amrit Nath Thulal

DEPARTMENT OF INFORMATION TECHNOLOGY,

AMITY SCHOOL OF ENGINEERING AND TECHNOLOGY

[AFFILIATED TO G.G.S.I.P.UNIVERSITY]

OCTOBER, 2008

Page 2: Seminar Report Generic Access Network Gan

TABLE OF CONTENTS

1. Abstract

2. Introduction

3. Theoretical Description

3.1 How does this dual mode service work

3.2 Basic requirements for using GAN services

3.3 Participating companies and vendors of the GAN

3.4 A note on the history of the GAN (also called as the UMA)

4. Technical Details

4.1 GAN functional architecture

4.1.1. GANC(GAN Controller)

4.1.2. Security gateway

4.1.3. Authentication, Authorization and Accounting (AAA) infrastructure

4.1.4. Dual mode handset

4.1.5. Standard Wi-fi access point

4.2 Modes of operation

Page 3: Seminar Report Generic Access Network Gan

5. Advantages

5.1 For Carrier

5.2 For Subscriber

6 . Disadvantages

7. GAN/UMA beyond the dual mode

7.1 Femtocell

7.2 Analog Terminal Adapter

7.3 Soft Mobile

8. Similar Technology

9. Conclusion

10. References

Page 4: Seminar Report Generic Access Network Gan

1. ABSTRACT

Generic Access Network (GAN) is a telecommunication system which extends mobile

services voice, data and IP Multimedia Subsystem/Session Initiation Protocol (IMS/SIP)

applications over IP access networks.

This report will attempt to discuss the details of the GAN, its evolution, its services,

architecture, and other implications.

Page 5: Seminar Report Generic Access Network Gan

2. INTRODUCTION

The Generic Access Network (GAN) is an evolving wireless communications system in

which mobile phone sets function seamlessly between local area networks (LANs) and

wide-area networks (WANs). Using GAN technology, a cell phone subscriber can

communicate by voice, data and multimedia. As GAN technology is implemented,

cellular telephone subscribers can expect improved coverage, the ability to use a single

phone set for all their voice communications and perhaps cheaper rates with a single bill

for Internet and voice communications.

Main application of this GAN/UMA is the Dual-mode Handset service.

Page 6: Seminar Report Generic Access Network Gan

3. THEORETICAL DESCRIPTION

3.1 How does this dual-mode service work

With dual-mode services(GSM and Wi-fi), subscribers make calls from outside the home

as they would ordinarily, using the GSM radio network at the standard tariff rate. But

inside the home, the call travels over the subscriber’s wireless broadband connection,

so the operator can enjoy a similar economic structure as VoIP-over-broadband

provider.

Page 7: Seminar Report Generic Access Network Gan

3.2 Basic requirements for using GAN services

To offer GAN dual-mode services, mobile operators need handsets, network controllers,

call control, the security to protect the mobile operator voice network from

Internet-based threats, and wireless access points for their subscribers.

3.3 Participating companies and vendors of the GAN

Alcatel

British Telecom

Cingular

Ericsson

Kineto Wireless

Motorola

Nokia

Nortel Networks

O2

Research in Motion

Rogers Wireless

Siemens

Sony Ericsson

T-Mobile US

Page 8: Seminar Report Generic Access Network Gan

3.4 A note on the history of the GAN (also called as the UMA)

In September 2004, the participating companies published the initial UMA

specifications and formally introduced them to the 3rd Generation Partnership Project

(3GPP) standards body.

In April 2005, an unprecedented eight months later, the UMA specifications were

incorporated into the 3GPP release 6 specifications. While referred to as "Generic

Access Network" or GAN, within the 3GPP specifications.

In mid 2006, mobile operators around the world began announcing their intention to

deploy dual-mode handset (DMH)-based UMA services.

Throughout 2007, there were constant announcement of new UMA-enabled dual-mode

phones to support the commercial service offers.

In early 2008, the first commercial UMA-based fixed line VoIP service appeared as well

as the first UMA-enabled softmobile client.

Page 9: Seminar Report Generic Access Network Gan

4. TECHNICAL DETAILS

4.1 GAN functional architecture:

As seen in the figure the GAN functional architecture consists of 5 basic components :

4.1.1. GANC(GAN Controller)

4.1.2. Security gateway

4.1.3. Authentication, Authorization and Accounting (AAA) infrastructure

4.1.4. Dual mode handset

4.1.5. Standard Wi-fi access point

Page 10: Seminar Report Generic Access Network Gan

4.1.1.GANC :

The GANC provides dual-mode handsets with alternative access

to GSM voice and GPRS data services.

For voice traffic, the GANC integrates directly into an

operator Mobile Switching Center (MSC) through the

A interface.

For data traffic, the GANC integrates directly into an

operator serving GPRS support node (SGSN) through

the Gb interface.

4.1.2. Security gateway :

The introduction of a GAN solution into an operator network raises

numerous security implications and vulnerabilities inherent in an

IP-based architecture. The security gateway provides two important

security roles in the GAN:

Secure authentication (through Extensible Authentication

Protocol–SIM [EAP-SIM] or EAP–Authentication and Key

Agreement [EAP-AKA]) of mobile subscribers

Termination of secure tunnels (through IP Security [IPSec])

with InternetKey Exchange Version 2 [IKEv2]) from the

handset.

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4.1.3. Authentication, authorization, and accounting (AAA) infrastructure:

The AAA infrastructure interacts with numerous elements in the GAN

architecture, including:

Security gateway : The AAA infrastructure interacts

directly with the security gateway to validate mobile

credentials during IPSec tunnel establishment. This

includes the use of EAP mechanisms for SIM-based

authentication using either EAP-SIM or EAP-AKA.

HLR: The AAA infrastructure includes a MAP Gateway

function for communication to the operator HLR using the

SS7 transport protocol. During authentication, the AAA

infrastructure is responsible for converting RADIUS

authentication messages from the security gateway into

SS7 MAP Invoke messages to the HLR. This allows the

existing HLR to verify a user on the GAN using the

IMSI/triplets sequence that is standard for GSM/GPRS

authentication.

Page 12: Seminar Report Generic Access Network Gan

4.1.4. Dual-mode handset:

The dual-mode handset allows an end user to connect to either a public

GSM radio network or a private Wi-Fi or Bluetooth radio network and

maintain the same service capabilities.

4.1.5. Standard Wi-Fi access point:

A standard Wi-Fi access point (or hotspot) is used to provide Wi-Fi access

to a dual-mode handset. This Wi-Fi access point may be enhanced with

specific Quality of Service (QoS) and security mechanisms, such

as rate-limiting for uplink traffic, Call Admission Control to

limit the number of dual-mode handsets that may associate with it,

802.1x encryption, etc.

Page 13: Seminar Report Generic Access Network Gan

4.2 Modes of operation:

A typical UMA/GAN handset will have four modes of operation:

GERAN-only: uses only cellular networks.

GERAN-preferred: uses cellular networks if available,

otherwise the 802.11 radio.

GAN-preferred: uses a 802.11 connection if an access

point is in range, otherwise the cellular network.

GAN-only: uses only the 802.11 connection.

In all cases, the handset scans for GSM cells when it first turns on, to determine its

location area. This allows the carrier to route the call to the nearest GANC, set the

correct rate plan, and comply with existing roaming agreements.

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5. ADVANTAGES

For the Carriers :

Instead of erecting expensive base stations to cover every nook and cranny of a

neighbourhood, GAN allows carriers to add coverage using low cost 802.11 access

points. When at home, subscribers have very good coverage.

In addition, GAN relieves congestion on the GSM or UMTS spectrum by removing

common types of calls and routing them to the operator via the relatively low cost

Internet

GAN makes sense for network operators that also offer internet services. Operators can

leverage sales of one to promote the other, and can bill both to each customer.

Some other operators also run networks of 802.11 hotspots, such as T-Mobile. They will

be able to leverage these hotspots to create more capacity and better coverage in many

populous areas.

Subscribers, not the network, pay directly for much of the costs associated with the

service. They pay for a connection to the Internet, effectively paying the expensive part

of the cost of routing calls from their location.

For the Subscribers :

Subscribers do not rely on their operator's ability to roll out towers and

coverage, allowing them to fix some types of coverage blackspot themselves

(such as in the home or office.)

Page 15: Seminar Report Generic Access Network Gan

The cheaper rates for 802.11 use, coupled with better coverage at home, make it

more affordable and practical to use cellphones instead of land lines.

GAN is currently the only commercial technology available that combines GSM

and 802.11 into a service that uses a single number, a single handset, single set

of services and a single phone directory for all calls.

6.DISADVANTAGES

Handsets must support 802.11 network access which requires additional space,

power and complexity and may affect the size, weight and battery performance

of the phone.Increasingly, consumers take advantage of unlimited or otherwise

high-volume data tariffs to make VoIP calls via SIP, as with Skype.

GAN will mean that this type of usage is more likely to be charged on a per-

minute or unit basis as with voice calls, which may increase the cost of mobile

calls made over IP.

Page 16: Seminar Report Generic Access Network Gan

7. GAN/UMA BEYOND THE DUAL MODE

While UMA is nearly always associated with dual-mode GSM/Wi-Fi services, it is actually

a ‘generic’ access network technology. It provides a generic method for extending the

services and applications in an operator’s mobile core (voice, data, IMS) over IP and the

public internet.GAN defines a secure, managed connection from the mobile core (GANC)

to different devices/access points over IP.

7.1 Femtocells:

Femtocells are small cellular base stations, typically designed for small

household or business environment. The GAN standard is currently used

to provide a secure, managed, standardized interface from a femtocell to

the mobile core network.

7.2 Analog Terminal Adaptor:

Recently T-Mobile announced a commercial trial of a fixed line VoIP

service. Similar to Vonage, consumers can port their fixed phone number

to T-Mobile, then T-Mobile associates that number with an ATA (analog

terminal adaptor). The consumer plugs the ATA into their home

broadband network and begins receiving calls to the fixed number over

the IP access network. Linksys developed a UMA-enabled ATA specifically

for this application.

Page 17: Seminar Report Generic Access Network Gan

7.3 Softmobile :

Consumers have started to use telephony interfaces on their PCs.

Applications like Skype offer a low cost, convenient way to access

telephony services while traveling. Now mobile operators can offer a

similar service with a UMA-enabled softmobile client. Developed by

Vitendo, the client provides a mirror interface to a subscriber’s existing

mobile service. For the mobile operator, services can now be extended to a

PC/laptop, and they can give consumers another way to use their mobile

service.

Page 18: Seminar Report Generic Access Network Gan

8. SIMILAR TECHNOLOGY

GAN/UMA is not the first system to allow the use of unlicensed spectrum to connect handsets

to a GSM network. The GIP/IWP standard for DECT provides similar functionality, but requires a

more direct connection to the GSM network from the base station. While dual-mode DECT/GSM

phones have appeared, these have generally been functionally cordless phones with a GSM

handset built-in (or vice versa, depending on your point of view), rather than phones

implementing DECT/GIP, due to the lack of suitable infrastructure to hook DECT base-stations

supporting GIP to GSM networks on an ad-hoc basis. GAN/UMA's ability to use the Internet to

provide the "last mile" connection to the GSM network solves the major issue that DECT/GIP has

faced. Had GIP emerged as a practical standard, the low power usage of DECT technology when

idle would have been an advantage compared to GAN. There is nothing preventing an operator

from deploying micro- and pico-cells that use towers that connect with the home network over

the Internet. Several companies have developed so-called Femtocell systems that do precisely

that, broadcasting a "real" GSM or UMTS signal, bypassing the need for special handsets that

require 802.11 technology. In theory, such systems are more universal, and again require lower

power than 802.11, but their legality will vary depending on the jurisdiction, and will require the

cooperation of the operator.

Page 19: Seminar Report Generic Access Network Gan

9. CONCLUSION

GAN dual-mode services to the home give mobile operators the opportunity for a

significant competitive advantage by accelerating fixed-mobile substitution, increasing

penetration, and reducing turnover. The GAN architecture provides an essential

prerequisite for dual-mode services—protecting the mobile operator’s voice network

from threats originating from the Internet. Because the security infrastructure that is

used to offer dual-mode services can be reused for other services, including IMS, the

investment in the GAN solution provides a competitive advantage for tomorrow’s

service as well as today’s.

Page 21: Seminar Report Generic Access Network Gan

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