270 likes | 640 Views
Vertical Handover Strategies. Presented by – Bulbul Ahamed 012112004 Rasel Ahmed 012112033 Tamim Anam 012112020 AKM Ashraful Hasan 012112021. Key Points. Introduction Vertical Handover (VH) Evolution of Cellular Communication
E N D
Vertical Handover Strategies Presented by – Bulbul Ahamed 012112004 Rasel Ahmed 012112033 TamimAnam 012112020 AKM AshrafulHasan 012112021 Vertical Handover Strategies
Key Points • Introduction • Vertical Handover (VH) • Evolution of Cellular Communication • VH in Heterogeneous Network • Handover Initiation Techniques • Fundamental Structure of USHA • Smart Decision Model • Technical Features of VHO • Limitations of VH Vertical Handover Strategies
Introduction In order to sustain connection and service in heterogeneous wireless environment, vertical handover is necessary. Now-a-days research focus is to optimize vertical handover so that optimized and application specific handover can be made possible. Vertical Handover Strategies
Vertical Handover • Vertical handover refers to automatic switching the communication/data session from one technology to the other. • Vertical handover may be referred to a process of transferring call connected to a network/data session from one channel connected in a cell to the core network of another. Vertical Handover Strategies
Evolution of Cellular Communication Vertical Handover Strategies
VH in Heterogeneous Network To access multiple wireless networks in heterogeneous wireless network, the mobile station or mobile devices will equipped with different network interfaces. The process through which user maintain his call without any interruption, when he moves across one network to another network is referred to as handoff or handover process. Vertical Handover Strategies
Horizontal Handoff BSS BSS AP AP Internet Vertical Handover Strategies
Vertical Handoff WCDMA WLAN AP BS Internet Vertical Handover Strategies
Handover Initiation Techniques On the bases of Received Signal Strength (RSS) from current and neighbouring Base Station (BS), it is determined that when to request the handover. Vertical Handover Strategies
Handover Initiation Techniques … Four different handover initiation techniques: • Relative Signal Strength • Relative Signal Strength with Threshold • Relative Signal Strength with Hysteresis • Relative Signal Strength with Hysteresis and Threshold Vertical Handover Strategies
Fundamental Structure of USHA • Universal Seamless Handover Architecture (USHA) proposed in, to supports the both handover techniques (Horizontal and Vertical Handover) with smaller change in its infrastructure. • USHA get the seamless handover process instead of using new transport protocol or new session layer by middleware design strategy. • USHA also works on upper layer. USHA occurs only on overlaid networks with various Internet access methods called soft handover. Vertical Handover Strategies
Smart Decision Model • In Vertical handover the Smart Decision Model (SDM) is used for reliable configuration. • The Handover Control Centre (HCC) describes the four components i.e. Device Monitor (DM), System Monitor (SM), Smart Decision (SD) and Handover Executer (HE). Vertical Handover Strategies
Smart Decision Model Process Normal phase • Collect the information from DM on each wireless interface in the subscriber list. • Get the status of current system from SM component. • To obtain the score of each wireless interface from subscriber list use the score function. Vertical Handover Strategies
Smart Decision Model Process… Priority Phase • Add the available interfaces in the subscriber list. • Delete the user specified devices from the subscriber list. • If subscriber list is empty then removed the devices from the step 1. Vertical Handover Strategies
Technical Features of VHO • The Technical feature of Vertical handover. describes three main categories: • Mobility Engineering, • Resource Management and • Service Management Vertical Handover Strategies
Difference between Vertical/Horizontal Handover Vertical Handover Horizontal Handover Access Technology Changed Not changed QoS Parameters May be hanged Not changed IP Address Changed Changed Network Interface May be change Not Changed Network Connection More than on connections Single connection Vertical Handover Strategies
Limitations of VH • It handles all the connections in same manner. When all TCP/IP connection automatically transfers from one interface to another, in this situation only one wireless interface (the best one) is used at that moment. • The second limitation of vertical handover is that vertical handover need the same network interface. All the wireless interfaces must be used as part of the same Mobile IP and DNS infrastructure because mobile nodes and peers must be able to reach the Mobile IP and DNS server. Vertical Handover Strategies
Any Questions? Vertical Handover Strategies