Cellular IP - A Local Mobility Protocol

Transcription

1 1 ellular IP - A Local Mobility Protocol András. Valkó ricsson Traffic Analysis and Network Performance Lab, and enter for Telecommunications esearch, olumbia University, New York andras@comet.columbia.edu Andrew T. ampbell, Javier omez enter for Telecommunications esearch, olumbia University, New York [campbell,javierg]@comet.columbia.edu

2 2 "One can think of as solving the "macro" mobility management problem. It is less well suited for more "micro" mobility management applications -- for example, handoff amongst wireless transceivers, each of which covers only a very small geographic area...."

3 3 vs. Hierarchical mobility management Internet w/ base station mobile Internet w/ mobile access network base station mobile - faster handoffs within a mobile access network - less load in the global Internet

4 4 equirements for a mobile access network protocol: Simple, cheap base stations Simple algorithms in mobile hosts ast handoff Smooth interworking with obustness (failures and radio channel problems) fficient use of the radio resource Little load by location management of idle mobile hosts Scalability and vertical handoffs

5 5 Mobile Access Networks as Wireless Overlay Networks metropolitan area mobile access network Internet w/ campus area mobile access network Mobile Access Networks will typically overlap allowing users to select the access network that actually gives best performance.

6 6 Mobile Access Network Internet w/ foreign agent A global Internet Mobile Access Network ellular IP - IP compatible - simple - scalable - robust

7 7 Uplink packets: shortest path Internet w/ foreign agent host A

8 8 ownlink packets: centralized location management approach vs. ellular IP s distributed data bases Internet w/? foreign agent host A Internet w/??? foreign agent A host?? - no tunnelling - nodes need no network-level view - control messaging minimized

9 9 ellular IP: Uplink packets create location information Internet w/ foreign agent host A Node is self-sufficient :

10 10 ellular IP: Handoff is automatical Internet w/ foreign agent host A - edirected uplink packets create new downlink path - Optimal reuse of previous path - No handoff control messaging

11 11 ontrol packets in uplink if no data Internet w/ foreign agent host A - ontrol packets are regular IP packets with no payload - They update routing entries - iscarded before reaching the Internet

12 12 ellular IP esign principles Location data base distributed Location information gained from mobile originated packets Soft state management Advantages Simple, self-sufficient nodes Simple mobile: just send control packets when no data No control messaging at handoff Soft states give built-in fault tolerance Handoff or faults do not differ from normal operation Problem (?) Load from control packets

13 13 Idle host location management trade-off total cost cost of maintaining location information cost of finding host when it has data location information on idle mobile hosts

14 14 ellular IP: Location management of idle hosts Internet w/ foreign agent host A - ache maintained in just some selected nodes - Local broadcast where no location information - Longer timeouts, less frequent control packets - omplete routing information established asap

15 15 ellular IP Summary istributed location data base Location information established by uplink IP packets Soft state management Location management of idle hosts is separated from active hosts urrent research xtension to ns2 ready, simulation studies now focus on performance Testbed on S platform being implemented ellular IP draft to be presented at next IT meeting