Re: [manet] ZRP simulation results

[Prince Samar <[e-mail]>]

Dear Mehran,

Here are some of my thoughts on your unusual simulation results.

- First a disclaimer: I am not familiar with the particular code for ZRP
that you are using. So, I cannot comment on the accuracy of the
implementation, or rule out bugs in the code.

- We consider ZRP as more of a routing protocol *framework* than "yet
another routing protocol out there." For a fair comparison of ZRP with
AODV, the reactive component (IERP) should be derived from AODV.
Similarly, when comparing ZRP with any other reactive/proactive routing
protocol, the IERP/IARP should be based on that particular routing
protocol. Please refer to [1] and [2] for guidelines to convert a reactive
or proactive routing protocol into IERP or IARP.

- At what network settings (node mobility, call rate etc.) did you compare
the results? And at what values of the routing zone radius for ZRP? If the
ratio of calling rate to mobility in your settings is very low, so that
highly reactive routing is preferred [3], then probably zone radius of 1
(or, 0) would be the optimal setting for ZRP. This setting corresponds to
pure reactive routing. Thus, the performance of ZRP would be at least be
as good as that of AODV, given that AODV is used as the IERP. Also,
clearly at this setting, the contribution of proactive (IARP) component to
routing overhead will be zero.

- Please make sure that the update interval for periodic routing updates
by IARP is set appropriately in relation to the degree of mobility in your
simulation. It sounds like the update interval is set for high mobility
(and thus the high proactive overhead) as compared to the actual degree of
mobility in your simulation settings. Please refer to [4] for a simple
'rule of thumb,' or [5] for a much more efficient scheme for this.

- According to version 4 of the ZRP internet draft, a node does not need
to maintain extended routing zones. Hence, the proactive component of the
routing overhead is considerably reduced in version 4.

- Independent Zone Routing (IZR), an enhancement to ZRP, is proposed in
[3]. IZR enables each node to independently autoconfigure its own optimal
zone radius depending on the network characteristics. Further, it provides
each node the ability to adapt its zone radius over time and space as
local network characteristics change. This significantly increases the
efficiency and scalability of the framework.

- You may find further simulation results on Zone Routing in [4] and [3].

[1] Zygmunt J. Haas, Marc R. Pearlman, Prince Samar, "The Interzone
 Routing Protocol (IERP) for Ad Hoc Networks," IETF Internet Draft, MANET 
 WG, July 2002.
[2] Zygmunt J. Haas, Marc R. Pearlman, Prince Samar, "The Intrazone 
 Routing Protocol (IARP) for Ad Hoc Networks," IETF Internet Draft, MANET 
 WG, July 2002.
[3] Prince Samar, Marc R. Pearlman, Zygmunt J. Haas, "Independent Zone 
 Routing: An Adaptive Hybrid Routing Framework for Ad Hoc Wireless 
 Networks," IEEE/ACM Transactions on Networking,  Vol. 12 ,  Issue 4, pp. 
 595-608, Aug. 2004.
[4] Zygmunt J. Haas, Marc R. Pearlman, "The Performance of Query Control 
 Schemes for the Zone Routing Protocol,"  ACM/IEEE Transactions on 
 Networking, vol. 9, no. 4, pp. 427-438, August 2001.
[5] Prince Samar, Stephen B. Wicker, "On the Behavior of Communication 
 Links of a Node in a Multi-Hop Mobile Environment," in The Fifth ACM 
 International Symposium on Mobile Ad Hoc Networking and Computing 
 (MobiHoc) 2004, Tokyo, May 2004.

Hope this helps.

Regards,
Prince


-------------------
Prince Samar, Ph.D.
Airvana Inc.
[phone]



On Thu, 3 Mar 2005, Mehran Abolhasan wrote:

: Hi All,
: 
: Just wondering, has anyone simulated the ZRP routing protocol? i simulated the 
: ZRP protocol using the code provided for version 2 of protocol (see 
: http://people.ece.cornell.edu/~haas/wnl/wnlprojects.html). I got some strange 
: results, in particular throughput results far less scalable that AODV. I am 
: not sure if there is a bug in this code or are these the actual results. I 
: have also noticed that the IARP routing part produces a lot of overhead. Are 
: there any major changes between version 2 and version 4, which address 
: overhead issues? 
: 
: If anyone has has performed a simulation study of ZRP interms of looking at 
: packet delivery radio, throught, control overhead, could you please refer me 
: to your paper, results or simulation code.
: 
: Kind regards,
: 
: 
: 


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