2008年7月6日星期日
比较多信道多接口ns2扩展: “Aguero.C.R” VS “MW-Node”
I try in this post to sum up and explicit the main differences between
the approach proposed by R.Aguero et al. in their how-to and ours with
the MW-Node. I hope it helps you choosing what better fits your needs.
1) R.Aguero et al., "Adding Multiple Interface Support in NS-2"
(document, http://personales.unican.es/aguerocr)
This document describes changes to enable support of multiple
interfaces. By to support multiple interfaces they mean to allow to have
more than one wireless stack below a single routing agent on a
MobileNode. All the wireless stacks are identical (same Mac/Phy). The
routing agent code has to be modified to handle more than one wireless
stack. This applies only to AODV-like routing agents, that is routing
agents using the standard MobileNode, not the SRNode (DSR) or the
AODVUUNode (AODV-UU) for example.
This functionality is basically what is provided by Hyacinth
(http://www.ecsl.cs.sunysb.edu/multichannel/), some flexibility added.
To this respect their contribution is to me very similar to the
resources available at http://www.cse.msu.edu/~wangbo1/ns2/nshowto8.html
2) Module-based Wireless Node (MW-Node patch + documentation,
http://www.q2s.ntnu.no/~paquerea/ns.html)
In the following, I focus on the main features of the MW-Node. For
implementation details and design choices please refer to the documentation.
A MW-Node is a standard Node (not a MobileNode) with capabilities -
wireless, mobility, (energy support, not functional yet) - added by
means of modules.
The purpose of this new design of wireless and mobile networking support
in ns2 is twofold:
- to support new features such as multiple channels/multiple interfaces, and
- to provide a common basis for implementation of any wireless routing
protocol instead of having each routing protocol as a particular case
(not to say a particular node object) as it is with the MobileNode.
We distinguish between:
- multiple channels: one single routing object handling several wireless
interfaces possibly on different channels, and
- multiple interfaces: several interfaces, possibly of different types
(e.g different Mac/Phy), with one routing object handling one interface.
Following these definitions, R.Aguero et al. how-to discusses multiple
channels support only, not multiple interfaces support. The MW-Node
supports both.
Note that routing agents cannot be used directly with the MW-Node, even
in the case of a node with a single interface, and need to be converted.
Some guidelines are provided in the documentation.
Also, the layout of the MW-Node differs from the layout of a standard
MobileNode and therefore from the layout proposed by R.Aguero et al.
In the MW-Node, the routing object lies before the address classifier.
This is to enforce that data packets pass through the routing object.
This is not the case with a standard MobileNode at the destination or at
a portal (wired-wireless) node.
Finally, a new network interface object is provided and enables:
- per interface operation control (e.g. bring up/down one of two
interfaces only)
- better wired/wireless integration.
Regards,
Laurent Paquereau
Q2S Centre of Excellence, NTNU
转自:
http://mailman.isi.edu/pipermail/ns-users/2007-February/058759.html
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