A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns N. A. Fikouras and C. Görg Department of Communication Networks University of Bremen

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Contents  Introduction to Mobile IP  Mobile IP Hand-offs Movement Detection Methods Agent Selection Agent Advertisements Regional Registrations  Complex Movement Patterns  Straight Line  Back & Forth  Simulation Setup  Simulation Results

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Mobile IP  MIP is an extension to IP  Equivalent to the post office forwarding service  Enables IP Roaming  Introduces IP Layer Hand-offs  During Hand-offs the Mobile:  Detects Movement Neighbouring Agent Discovery Agent Selection  Registers  Hand-offs cause Packet Loss

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Movement Detection  Advertisement Based  Requires Periodic Broadcast Agent Advertisements  Agent Discovery = Movement Detection  Hint Based  Requires Link-Layer Hand-off Information  LL Hand-off Hint = Movement Detection  Agents are solicited for Unicast Ads  Periodic Advertising is not needed  Solicited Ads = Agent Discovery

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Agent Advertisements  Optimal Movement Detection requires high advertisement rates  High rates affect link throughput  Advertisements require the presence of Agents  Bibliography considers 100ms as optimal period Throughput of an 914MHz Lucent WaveLAN DSSS radio interface with respect to MIP agent advertisement size and period

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Movement Detection Methods  Advertisement Based  Lazy Cell Switching (LCS) Wait for Serving Agent to expire Agent lifetime is 3 * Advertisement Period (on average: 2,5*period)  Eager Cell Switching (ECS) Hand-off upon Agent Discovery (on average: 0.5*period)  Hint Based  Hinted Cell Switching (HCS) Solicit when „hinted“ Hand-off upon Agent Discovery (Mobile Node – Agent Round Trip Time)

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Simulation Software  Network Simulator:  a discrete event simulator  from UCB/LBNL/VINT  supports Mobile IP  extended to support: LCS, ECS and HCS Agent Selection as per Sun Labs MIP Regional Registrations Screenshot from the Simulation Visualisation with the Network Animator (NAM)

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Simulation Setup  FA-MN link is wirelined + No Wireless Loss  Hand-offs managed through manipulation of links + Controlled Cell Cross time  Simulations terminated at 5% relative error rate  Simulation Traffic  RTP stream  Emulates VAT traffic PCM encoding 78 kbps 200 octets/packet 20 ms inter-packet delay

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Complex Movement Patterns  Simulation Scenarios  29 Location update frequency (locupd) rates (0.1 locupd/sec – 20 locupd/sec)  Mobile roams with a given rate on a per sec basis  Variable time between location updates - uniform(0,2/rate) Represents variable cell size with constant size OR Constant cell size with variable speed  Straight Line Movement (SLM) Simulated topology: 50 FAs in a circle With every completed circle all Agents are reinitialised –Straight line movement without patterns  Back & Forth Movement (BnFM) Simulated topology: 2 FAs

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, SLM – Service Disruption  During MIP Hand-offs a Mobile may not exchange traffic (Service Disruption)  Unsuccessful Agent Selection leads to extended Service Disruption  ECS/HCS outperform LCS/fLCS  ECS/HCS Hands-off upon Agent Discovery  HCS outperforms ECS due to faster Agent Discovery  ECS waits for the next periodic broadcast  HCS is “hinted” movement through LL hints  HCS may solicit for Unicast Ads.

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, SLM – Service Disruption (cont.)

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Agent Selection  Agent Selection is based on the LocalMaTable (Sun Labs MIP v1.2)  Selection Criteria:  LCS (supported by Sun MIP): Always the Serving Agent when active OR Agent with longest lifetime  ECS/HCS: Most Recently Discovered Agent OR Agent with longest lifetime  fast extension (fHCS, fLCS)  Ignore the LocalMaTable  Make Agent Discovery based on Solicitation/Unicast Ads. Agent Selection in Sun Labs MIP v1.2

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, BnFM – Service Disruption  In BnFM Service Disruption may be completed without a prior MIP hand-off  HCS faster Agent Discovery is not useful in BnFM. There are no agents to be discovered. ! Agent Selection based on the LocalMaTable reacts only in the case of Agent Expiration  In HCS and with high lockupds expiration does not occur due to hinted solicitation  fHCS outperforms HCS due to more successful Agent Selection  The fast extension is not based on the LocalMaTable

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, BnFM – Service Disruption (cont.)

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Conclusions (SLM)  MIP hand-offs depend on Movement Detection  MIP Movement Detection involves  Agent Discovery  Agent Selection  LCS/fLCS, ECS are based on Agent Ads. - Slow or unsuccessful Agent Discovery  LCS, ECS are based on the LocalMaTable - Unsuccessful Agent Selection  HCS/fHCS are based on LL hand-off „hints“ + Faster Agent Discovery  In Straight Line Movement HCS outperforms fLCS/LCS, ECS

A Comparison of Wireless Mobile IP Movement Detection Methods for Complex Movement Patterns Workshop: IP in Telekommunikationsnetzen Bremen, Conclusions (BnFM)  In Back & Forth Movement Agent Discovery performance is not as important  There are no new agents to be discovered  Agent Selection is more critical  LocalMaTable based methods depend on Agent Expiration  HCS does not expire agents due to solicitations  fHCS is based on the fast extension  Ignores LocalMaTable + Adapts to local Agent (Known or newly Discovered) + Performs more successful Agent Selection  Packet loss is directly dependent on service disruption  HCS/fHCS demonstrates constant best performance in both Straight Line and Back & Forth Movement Patterns