14-12-2012, 04:53 PM
Vertical and Horizontal Handoff in Wireless Internet Access
Vertical and Horizontal.ppt (Size: 1.05 MB / Downloads: 93)
Wireless Internet Access
Different wireless networks available
E.g. GSM/GPRS, UMTS, WiFi, WiMAX
Mobility is Essential
Changes the users’ behavior
Internet access from any wireless device
Always best connected
Multi-mode equipment
Handover in WiFi
Mobile terminal-controlled, network assisted handover
The mobile node chooses new AP to re-associate with
The network exchanges information after re-association
Handover in four parts
Handover UMTS-WiFi
Open coupling
No common subscriber database and billing
Poor handover performance
Loose coupling
Common subscriber database and billing
Improved handover performance
Tight coupling
UMTS core network interface must be supported single operator
Improved handover performance
Mobile IP
Changing the point of connection may change the IP-address
Disrupting the on-going session
Mobile IP is a network-layer mobility management solution
Hides the mobile node’s movement from its corresponding node
Two IP-addresses involved
Home Address: the point of contact for corresponding nodes
Care-of-Address: the current point of connection
Two agents involved
Home Agent: acts as a proxy and forwards packets to the CoA
Foreign Agent: allows mobile nodes to register in ”foreign” subnets
Unlicensed Mobile Access (UMA)
3GPP standard for cellular systems and unlicensed wireless networks handover
A mobile centric version of IEEE 802.21
The UMA Network Controller (UNC)
Provides an interface into mobile operators core network
Secure transport of mobile signaling over IP
Extends a mobile operator’s services over IP-based access networks
Use WiFi to improve coverage and performance of 3G services
CALM
ISO approved framework for continuous communication across various interfaces and media for vehicular users
ISO TC204/WG16 – Wide Area Communications
IEEE 802.11/11p/15/16e/20, 2G/3G, and ITS systems
Application support
In-vehicle Internet access
ITS applications (focus on Vehicle Safety Communication)
V2V communication
Vertical handover based on IPv6 protocols (ISO 21210)