APRIL, 2002 PARIS IPCN02 M.ERGEN FAST HANDOFFS with GPS for MOBILE IP by Mustafa ERGEN Authors: Mustafa Ergen, Sinem Coleri, Baris Dundar, Anuj Puri, Pravin Varaiya Berkeley WOW Group Department of Electrical Engineering and Computer Science University of California Berkeley WW O B E R K E L E Y

APRIL, 2002 PARIS IPCN02 M.ERGEN Motivation for Fast Handoff in Mobile IP Previous Work on Fast Handoff Location Based Fast Mobile IP Protocol  Protocol Description  Control Messages  Security Simulation and Implementation System Extensions Conclusion Outline

APRIL, 2002 PARIS IPCN02 M.ERGEN Primary Aim of Mobile IP  Robust communication between mobile users Major Problem in Mobile IP  Achieving QoS requirements of real-time applications Solution:  High bandwidth through smaller cells Motivation

APRIL, 2002 PARIS IPCN02 M.ERGEN Small Wireless Cells  Advantage: More number of users  Diameter of cell decreases by N  number of cells in a certain area increases by N²  number of available channels increases by N²  Disadvantage: Mobile host crosses cells more often  More number of handoffs Motivation

APRIL, 2002 PARIS IPCN02 M.ERGEN HA CH time Hand Over Begins New FA Detection Registration_Request Registration_Reply Receive Packet MH New FA Registration Ends Max_Time_One_Beacon_Period Packet Beacon Time Diagram of a Hand_off Basic Mobile IP Handoff

APRIL, 2002 PARIS IPCN02 M.ERGEN Previous Work on Fast Handoff Basic Mobile IP  Performs basic functions Transparency and Handoff Support  Not optimized for handoff Internet HA DFA FA MH FA

APRIL, 2002 PARIS IPCN02 M.ERGEN Previous Work on Fast Handoff Optimization in Mobile IP Hand-off  Through domains Decreases overhead by localization of registration Still suffers from delay and packet loss in intra-domain handoff Leaves inter-domain movement to the basic Mobile IP  Through multi-cast addresses Assigning multi-cast address to current access point and handoff targets Manual determination of handoff targets Requires continuous messaging to learn about new multi-cast addresses Multi-cast address conflicts Internet HA DFA FA MH FA

APRIL, 2002 PARIS IPCN02 M.ERGEN Location Based Fast Mobile IP Protocol Goals of the Protocol:  Support uninterrupted operation of real-time applications Lower Handoff Delay, less Packet Loss  Decrease messaging burden of fast handoff  Avoid manual configuration for fast handoff  Avoid possible address conflicts

APRIL, 2002 PARIS IPCN02 M.ERGEN Location Based Fast Mobile IP Protocol Structure of the internet

APRIL, 2002 PARIS IPCN02 M.ERGEN Intra-domain  Uses geographical information.  Finds adjacent FAs of the current attached FA.  Send the datagram to the adjacent FAs besides current FA.  Reduces handoff time and packet loss. Inter-domain  Gives HA functionality to a DFA “Local Home Agent (LHA)”.  Does not bother HA for movements within a geographical radius.  Reduces handoff time and control messaging.  Distribute HA database dynamically. Location Based Fast Mobile IP Protocol

APRIL, 2002 PARIS IPCN02 M.ERGEN Intra-Domain Handoff Example Soda Hall 3 rd Floor

APRIL, 2002 PARIS IPCN02 M.ERGEN Intra-Domain Handoff Internet HA DFA FA MH FA CH FA DFA Takes packet from HA or CH. Decapsulates packet and checks its visitor list. Sends the packet to the related branches according to Location FA table. FA If it is current FA, send the packet to MN. Else If it is an adjacent FA, buffer the packets. Else send the packet to the related branches according to Location FA table.

APRIL, 2002 PARIS IPCN02 M.ERGEN Inter-Domain Handoff Current inter-domain handoff compared to our system DFA MHMH FAFA FAFA MHMH FAFA FAFA HA DFA FAFA FAFA Fast Inter-domain handoff necessary due to  Increase in the battery power of laptop computers  Tiling of the world into small wireless cells

APRIL, 2002 PARIS IPCN02 M.ERGEN Inter-Domain Handoff Current inter-domain handoff compared to our system DFA MHMH FAFA FAFA MHMH FAFA FAFA HA DFA FAFA FAFA Procedure of Inter-domain handoff in Basic Mobile IP:  MH sends registration request to a FA in a new domain  FA sends request to DFA  DFA sends request to HA  HA sends registration reply to MH Disadvantage of Basic Mobile IP:  Delay and packet loss due to wasteful trip of registration messages

APRIL, 2002 PARIS IPCN02 M.ERGEN Inter-Domain Handoff Current inter-domain handoff compared to our system DFA MHMH FAFA FAFA MHMH FAFA FAFA HA DFA FAFA FAFA Procedure of Fast Inter-domain handoff:  MH sends registration request to a FA in a new domain  FA sends request to DFA  DFA sends request to HA or local home agent  HA or local home agent sends registration reply to MH Advantage of Fast Inter- Domain Handoff:  Decrease in delay and packet loss due to registration

APRIL, 2002 PARIS IPCN02 M.ERGEN Inter-Domain Handoff How do we decide whether to register to a local home agent or HA ?  Register to old LHA instead of HA as long as DFA of MH is inside the circle  Angle d1: Distance between LHA (DFA) and HA d2: Distance between LHA and Current DFA R : Movement range without changing LHA

APRIL, 2002 PARIS IPCN02 M.ERGEN Messaging: Registration Messages TYPE HOME AGENT GEOGRAPHICAL LOCATION LOCAL HOME AGENT GEOGRAPHICAL LOCATTON LOCAL HOME AGENT IP ADDRESS IDENTIFICATION TARGETED DOMAIN FOREIGN AGENT ADDRESS HOME ADDRESS CARE OF ADDRESS OTHER EXTENSIONS…… LIFETIME TYPECODELIFETIME HOME ADDRESS TARGETED DOMAIN FOREIGN AGENT ADDRESS IDENTIFICATION LOCAL HOME AGENT IP ADDRESS LOCAL HOME AGENT GEOGRAPHICAL LOCATION OTHER EXTENSIONS Registration Request Format Registration Reply Format

APRIL, 2002 PARIS IPCN02 M.ERGEN Messaging: Location Advertisement Messages Aim:  Eliminate manual configuration Distribute the location of each FA to other FAs inside domain Content:  Location and CoA of the FA that it originates Procedure:  Every FA advertises its CoA and position to its neighbors  Every router sends the incoming LAM to its neighbors

APRIL, 2002 PARIS IPCN02 M.ERGEN Security Uses security features of current Mobile IP(IPSec etc…) Requires security association between DFAs New FA delivers buffered datagram to MH only after finishing secure registration

APRIL, 2002 PARIS IPCN02 M.ERGEN Simulation: Intra-Domain Handoff DFA MH FA Intra- Domain Handoff Scenario Packet audio source Packet inter-arrival time: 20ms Average packet size: 200bytes Constant traffic to MH

APRIL, 2002 PARIS IPCN02 M.ERGEN Handoff Time = Discovery Time + Registration Time Maximum Discovery Time = Beacon Period Link: 2 Mbps, 4ms Simulation: Intra-Domain Handoff

APRIL, 2002 PARIS IPCN02 M.ERGEN Human ear can tolerate approximately 200 ms delay at maximum *We achieved 141ms max inter-arrival time* Link: 2 Mbps, 4ms 5 Mobile Node Buffer Size 10 Simulation: Intra-Domain Handoff

APRIL, 2002 PARIS IPCN02 M.ERGEN Simulation: Inter-Domain Handoff Distance α Number of nodes in between Delay DFA MH FAFA FAFA DFA MH FAFA FAFA HA DFA FAFA FAFA Inter- Domain Handoff Scenario

APRIL, 2002 PARIS IPCN02 M.ERGEN  = arcsin 1/5 Simulation: Inter-Domain Handoff

APRIL, 2002 PARIS IPCN02 M.ERGEN Implementation: Intra-Domain Handoff HA Software  Two threads Registration protocol  Listens for UDP registration requests  Updates Binding Table upon request Tunneling Protocol  Listens to traffic in home network  Sends packets for MH to its current CoA

APRIL, 2002 PARIS IPCN02 M.ERGEN Implementation: Intra-Domain Handoff DFA, FA Software Process 1: Agent Advertisement Protocol  Sends out agent advertisements periodically Process 2  Thread1: Registration Protocol Updates Binding Table upon registration Sends all buffered packets if any  Thread 2: Tunneling Protocol Sends packets to handoff targets Buffers incoming packets if adjacent FA

APRIL, 2002 PARIS IPCN02 M.ERGEN Implementation: Intra-Domain Handoff MH Software Thread1: Listening thread  Listens for MAC layer packets to get the source address and sequence number of last packet Thread 2: Registration Protocol  Listens for agent advertisement messages  Registers to new FA

APRIL, 2002 PARIS IPCN02 M.ERGEN Implementation: Intra-Domain Handoff Basic Mobile IP  Unrecoverable throughput decrease during handoff  Longer handoff period Our Fast MIP scheme  Decrease in throughput compensated by sending the packets missed during handoff  Shorter handoff period

APRIL, 2002 PARIS IPCN02 M.ERGEN Implementation: Intra-Domain Handoff Basic Mobile IP  Number of lost packets is constant for the same sending rate No buffer used  Number of lost packets increases as sending rate increases Our Fast MIP scheme  Packet loss can be eliminated by choosing enough buffer size.  Required buffer size increases as sending rate increases

APRIL, 2002 PARIS IPCN02 M.ERGEN System Extensions Determining the location of indoor access points (FAs).  GPS support for only outdoor settings  Location support for indoor environments via Use of infrared signals (Active Badge Location System) Use of concurrent radio and ultrasonic signals (Cricket)

APRIL, 2002 PARIS IPCN02 M.ERGEN System Extensions Roaming at the boundary of the domain  Introductory message to adjacent DFA with CoA and location  Forwarding of packets to handoff targets by adjacent DFA FA Domain A Domain B DFA

APRIL, 2002 PARIS IPCN02 M.ERGEN System Extensions Avoiding Ping-pong effect  Registration to new access point like a registration update Packets are already in new FA FA MH Data Registration time

APRIL, 2002 PARIS IPCN02 M.ERGEN Conclusion Goal  QoS for Wireless Real Time Application  Distributing Home Agent Functionality Intra-domain Handoff  Sends packets to handoff targets Inter-domain Handoff  Geographical Boundary and Local Home Agent Messaging Security Simulation  Registration time, Packet inter-arrival time Implementation  Instantaneous throughput, Buffer size System extensions