Subject: MobiCom'98 Paper results

From: Wang Qiang <[email-masked]>
Date: Tue, 9 Jan 2001 22:27:54 +0800

Hello ns users,

I have a question regarding the simulation results presented in CMU's
MobiCom'98 paper "A performance comparison of multi-hop wireless ad hoc
network routing protocols".  I'm trying run the simulation for DSDV-SQ, DSR,
AODV-LL and TORA as mentioned in the paper and see if the results could be
reproduced.
I'm using ns-allinone-2.1b7 package installed on RedHat Linux 7.0.  So far
the results for DSDV-SQ and DSR are close to those presented in the paper.
However, I CAN'T get the same output for AODV-LL protocol!  I set the
following constants as listed in the paper:

#define AODV_LINK_LAYER_DETECTION

#define MY_ROUTE_TIMEOUT  	600
#define ACTIVE_ROUTE_TIMEOUT 	300
#define REV_ROUTE_LIFE		3
#define BCAST_ID_SAVE		3

#define NETWORK_DIAMETER	50

#define NODE_TRAVERSAL_TIME	0.04

#define HELLO_INTERVAL		1
#define ALLOWED_HELLO_LOSS	3
#define BAD_LINK_LIFETIME	3

#define RREP_WAIT_TIME		6.0
#define LOCAL_REPAIR_WAIT_TIME 0.15
#define MAX_RREQ_TIMEOUT	10.0

#define TTL_START			1
#define TTL_THRESHOLD		7
#define TTL_INCREMENT		2

#define MaxHelloInterval 	( 1.25 * HELLO_INTERVAL )
#define MinHelloInterval 	( 0.75 * HELLO_INTERVAL )

But after a few runs using the same scenarios files and movement pattern
files as used for DSDV-SQ and DSR, at 20m/s max. speed, 0s pause time and 20
CBR sources, the AODV_LL packet delivery ratio value is around 97.2%, BUT
the routing overhead value insists to be around 55489.5, which is an order
of magnitude less than the value of over 120,000 presented in the paper!!!
Even after I changed MY_ROUTE_TIMEOUT to 60 and ACTIVE_ROUTE_TIMEOUT to 50,
the outcome remain the same!  Could someone please give me some help?  How
should I set those parameters to produce the same settings as in the
MobiCom'98 paper?
Your help is sincerely appreciated!

Wang Qiang

---

From: "Samir R. Das" <[email-masked]>
Date: Tue, 9 Jan 2001 16:10:03 -0500

Hello Wang,

The simulation model of AODV-LL that you are using is not the same as
the one used by the CMU group for their MobiCom98 work. The model
implementation has been improved much over the implementation they
used. Also the protocol specs changed and reflect a later version of
the protocol.

So I am not surprised that you are seeing much less routing overhead.
This probably is due to a better pacing of route discoveries and use
of expanding ring search.

Samir Das

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of Wang Qiang
> Sent: Tuesday, January 09, 2001 9:28 AM
> To: [email-masked]
> Subject: MobiCom'98 Paper results
>
>
> Hello ns users,
>