Subject: Inconsistency in ns simulation of wireless propagation loss

From: Leonard Miller <[email-masked]>
Date: Wed, 27 Sep 2000 14:15:19 -0400

In the ns simulation of the propagation loss for wireless ad hoc
networks (9/18/00 version), there is an inconsistency in the calculation
of propagation loss, regarding the treatment of the system loss
parameter.  In short, the system loss is applied to the shorter link
distances (for which the model uses free space propagation) and not to
the longer link distances (for which a fourth-power propagation model is
used).  Simulations using ns for which the system loss was assumed to
be  L = 1 (0 dB) are not affected.

Details and recommended changes are given at the following URL:

http://www.isi.edu/nsnam/archive/ns-users/webarch/2000/msg04497.html

--Len Miller
________________________________________________________
*._..*.*_.***__*..*._..*._..*.*._.***._*_***_.*..*...*_*
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Leonard E. Miller, Wireless Commun. Technologies Group
    National Institute of Standards & Technology (NIST)
    100 Bureau Drive Stop 8920, Bldg. 820, Room 445
    Gaithersburg, Maryland 20899-8920
Phone: 301-975-8018        Fax: 301-590-0932
email: [email-masked], [email-masked]
http://w3.antd.nist.gov/wctg/