Subject: The throughput that can be provided by wireless networks

From: "P. R. Kumar" <[email-masked]>
Date: Thu, 3 Dec 1998 05:48:01 -0600 (CST)

Dear Colleagues,

I am grateful to Dr. Kimberly King for asking us to make explicit
whether the results on the throughput that can be provided by 
wireless networks even apply when multiple technologies are used for routing.

The results do apply. It does not matter if the channel is split into
several subchannels.

A revised paper showing explicitly that this is the case, 
a well as an additional simple argument for why the
throughput can never grow faster than 
O( 1 /sqrt(n) ) 
even when nodes are optimally located and immobile is available
as a postscript file from:

http://black.csl.uiuc.edu/~prkumar/capacity.ps

If you want a hard copy, just let me know ([email-masked]).

Regards,
Kumar

--------------
P. R. Kumar
Professor, Dept. of Electrical and Computer Engineering, and
Research Professor, Coordinated Science Lab

Univ. of Illinois                       Off: 217-333-7476
CSL                                     Sec: 217-333-0282
1308 West Main St                       Fax: 217-244-1653
Urbana, IL 61801                        WWW: http://black.csl.uiuc.edu/~prkumar

---

From: Ken Carlberg <[email-masked]>
Date: Thu, 03 Dec 1998 09:09:18 -0500

Hello,

at the risk of speaking for kimberly, i have a couple of comments. 
first, thanks. you've given some of us some interesting to chew on
and a tangible notation to play with.

as for the following...

> The results do apply. It does not matter if the channel is split into

i'm not sure i understand the context you speak of when you refer to
'multiple technologies' and splitting _a_ channel to several subchannels.

MANET's charter focuses on IP, implying that the solution space for ad-hoc 
networks is targeted at IP and not a specific subnet technology.  and
granted, the limitations of the physical subnet(s), as in plural, can be 
expected to affect the throughput and effectiveness of a MANET protocol.

but when i think of MANET and different technologies, i think of cases 
where a wireless IP network can be comprised of omni-directional and
directional links (eg, routers that have UHF and L-band interfaces).
certainly, in the military, these type of cases exist today, and i think
a commercial case can be made for this scenario as well.

hence, i think your paper tells us a worst case scenario for a single
technology (i.e., single frequency range) system and all the entities
that reside within it.

cheers,

-ken