Transcript PPT_692430028

WLAN-GPRS INTEGRATION FOR
NEXT-GENERATION MOBILE
DATA NETWORKS
通訊工程所 蔡名岳
692430028
Outline
1. INTRODUCTION
2. INTEGRATED WLAN AND CELLULAR
3.
4.
5.
6.
7.
DATA NETWORKS
INTERWORKING ARCHITECTURES
CURRENT STANDARDIZATION
ACTIVITIES
A TIGHT COUPLING ARCHITECTURE
A LOOSELY COUPLED ARCHITECTURE
CONCLUDING REMARKS
1.INTRODUCTION
• More necessity and less luxury on the
ability to communicate
• 2G -> 2.5G (GPRS) -> 3G
• Delay of 3G cellular networks
– offerings with “3G-like” services in efforts to
generate new revenue stream in today’s
environment.
2.INTEGRATED WLAN AND
CELLULAR DATA NETWORKS
• ROAMING
• SESSION MOBILITY
• ENHANCED MOBILE APPLICATIONS
2.INTEGRATED WLAN AND
CELLULAR DATA NETWORKS
• Cellular data network provide
– low-speed data service
– over a large coverage area.
• WLAN provides
– high-speed data service
– over a geographically small area.
2.INTEGRATED WLAN AND
CELLULAR DATA NETWORKS
2.INTEGRATED WLAN AND
CELLULAR DATA NETWORKS
• ROAMING: ownership/management
•
problem
Cellular owned WLAN
– operators are able to enhance their data service
capabilities with high-speed data connectivity
• WISP owned WLAN
– The WISP may partake in revenue sharing with the
cellular operator, based on the particular roaming
agreements between the two parties.
2.INTEGRATED WLAN AND
CELLULAR DATA NETWORKS
• SESSION MOBILITY
– An evolutionary step from roaming in this
integrated environment.
– Session is defined here as a flow of IP packets
between the end user and an external entity
– EX:FTP,HTTP
2.INTEGRATED WLAN AND
CELLULAR DATA NETWORKS
• ENHANCED MOBILE APPLICATIONS
– The possibility of cellular customers being connected
to two different access networks, a number of
enhanced applications can be enabled.
– take advantage of the fact that the end user is always
connected through a low-speed cellular network and
sometimes connected through a high-speed WLAN.
– EX: a mobile email application that schedules the
delivery of large files when the mobile is connected to
the WLAN network, and delivers only synopses of
emails when the mobile is connected to the GPRS
network.
3.INTERWORKING
ARCHITECTURES
• loose coupling and tight coupling
4.CURRENT STANDARDIZATION
ACTIVITIES
1. Common billing and customer care
2. 3GPP system-based access control and
3.
4.
5.
6.
charging
Access to 3GPP GPRS-based services
Service continuity
Seamless services
Access to 3GPP
5.A TIGHT COUPLING
ARCHITECTURE
• Tight coupling architecture provides a novel
solution for interworking between 802.11 WLANs
and GPRS
–
–
–
–
–
–
–
Seamless service continuation across WLAN and GPRS
Reuse of GPRS AAA.
Reuse of GPRS infrastructure
Support of lawful interception for WLAN subscribers
Increased security
Common provisioning and customer care
Access to core GPRS services
5. A TIGHT COUPLING ARCHITECTURE
6. A LOOSELY COUPLED
ARCHITECTURE
• In tight coupling, the WLAN data traffic
does not pass through the GPRS core
network but goes directly to the operator’s
IP network
6. A LOOSELY COUPLED ARCHITECTURE
6. A LOOSELY COUPLED
ARCHITECTURE
• AUTHENTICATION
• An authentication similar to GPRS may occur
•
within the WLAN network, depending on the
particular implementation.
Where the GPRS operator owns the WLAN
– the operator will reuse SIM-based authentication
(within the WLAN environment.
– for a subscriber to access services provided by a
GPRS operator over any WLAN access network,
regardless of whether the WLAN is owned by a GPRS
operator, (U)SIM-based authentication may be used.
6. A LOOSELY COUPLED
ARCHITECTURE
• ENCRYPTION
– A commonly believed weakness of the 802.11 WLAN
standard is in its encryption technology.
– Wired Equivalent Privacy (WEP) has been shown to
be a relatively inefficient encryption scheme, if used
as is as the only form of encryption.
– With the use of EAP, WEP may be enhanced by the
use of a unique session key for each user of the
WLAN.
6. A LOOSELY COUPLED
ARCHITECTURE
• BILLING
– Integrated billing is achieved via the billing mediator
function in the loosely coupled architecture of Fig.8
• SESSION MOBILITY
– Mobile IP (MIP) can be used to provide session
mobility across GPRS and WLAN domains. The MIP
framework consists of a MIP client (the MS), a foreign
agent (FA), and a home agent(HA).
CONCLUDING REMARKS
CONCLUDING REMARKS
CONCLUDING REMARKS