1. Zone Routing Protocol (ZRP) Update
Zygmunt Haas & Marc Pearlman
Wireless Networks Laboratory
Cornell University

2. Outline ZRP overview Bordercast Upgrade: Unicast to Multicast
bordercast tree
extended routing zone
revised query control
Revised ZRP Architecture
Simulation Models / Open IERP

3. Basic Query Propagation via Flood Searching
Unicasts messages: 36
Single Channel Broadcasts: 9

4. Directing Queries Outward: Routing Zones and Bordercasting
Bordercast (unicast)
Flood Search
LL uni
LL nb
Each node proactively tracks routing zone: set of nodes with min distance no greater than r hops
Forwards queries to peripheral nodes: routing zone members at min dist of r hops

5. Comments and Concerns About Bordercasting
Relaying queries to peripheral nodes may be more efficient but…
Overlapping routing zones lead to redundancy
Resolved by query control mechanisms that identify and discard redundant queries
Bordercasting is more efficient than flooding searching, but why? (not all links traversed, but some links traversed multiple times)
What about single channel neighbor broadcast?

6. Multicasting: A More Intuitive Way to Bordercast
Bordercast (multicast)
Flood Search
LL uni
LL nb
No link is traversed more than once, many never traversed.
Neighbor broadcast can be used to relay messages simultaneously to multiple downstream

7. Multicast Bordercast Options
Append bordercast tree to message.
link state of surrounding r hops (routing zone)
reduced query packets but increase packet length
Each node constructs all the bordercast trees for which it is a forwarding member.
link state of surrounding (r-1) + (r) = 2r-1 hops (Extended routing zone)

8. Forwarding Packets to the “Frontier”
uncovered
frontier covered
non-frontier covered
Only “frontier covered” nodes need to receive message

9. Query Control: Detection / Termination
Detection: For every received message, record
Query ID
Address of bordercasting node
Termination: Do not forward along downstream branch if each downstream peripheral node either:
Lies inside the routing zone of bordercasted node (not frontier covered)
Has been relayed to by this node (just plain redundant)

10. Old ZRP Architecture
Locally proactive IntrAzone Routing Protocol (IARP)
(any localized proactive routing)
Globally reactive IntErzone Routing Protocol (IERP)
(any reactive routing protocol)
bordercasting, query control (and hop-by-hop route computation)
(BRP) IP

11. Route Discovery Protocol Stack In Action
IERP
IERP
BRP
BRP
BRP
BRP IP IP IP IP A B C D
IERP only processes query packet every rth hop
BRP must provide “hop by hop” route discovery processing
Tight integration of routing protocol with BRP

12. Revised Route Discovery Protocol Stack Operation
IERP
IERP
IERP
IERP
BRP
BRP
BRP
BRP IP IP IP IP A B C D

13. Pulling Apart the IERP and BRP3
BRP cache
index
index 2
BRP header
downstream neighbors
packet
packet
BRP 1 4
End up with application independent bordercasting

14. New ZRP Architecture
Locally proactive IntrAzone Routing Protocol (IARP)
(any localized link state protocol)
Globally reactive IntErzone Routing Protocol (IERP)
(any reactive protocol)
route query
Application Ind. Bordercasting
(BRP)
route reply, route error, etc. IP

15. New OPNET and ns-2 Models Available Soon
IARP and BRP as described in draft
Different versions of IERP will be offered (depending on availability of existing models)
AODV
DSR
TORA
Two “flavors”: routing zone aware and unaware