Subject: RE: research topics

From: "Groten, D." <[email-masked]>
Date: Tue, 30 Jan 2001 17:18:52 +0100

Hi,

Robin Poss wrote:
>(...)
>Second idea:
>-------------
>How about a "dual" mobile phone, able to switch
>between a normal cellphone mode and an ad-hoc mode,
>the decision to swich being based, for example, on
>maximizing battery life, or minimizing bandwidth
>usage? In ad-hoc mode, the phone would use a chain of
>other phones not to reach the party called, but to
>reach the nearest (or otherwise clerverly chosen) base
>station.
>(...)
>I think "3G TR 25.924 ,Opportunity Driven Multiple
>Access" deals with a similar idea.

Let me add some information about ODMA, as proposed in 3G TR 25.924. In a
CDMA system (which 3G is), the total power of multiple users at a receiver
determines the noise floor after decorrelation. Therefore, power control is
of crucial importance to all CDMA systems. ODMA aims to reduce the power per
call by finding the optimum communication opportunity in an intelligent
network. It is proposed to be an added feature of the UMTS-TDD mode
(unpaired frequency band). Initial simulations by Vodaphone have shown that
a significant increase in capacity can be obtained, mostly in environments
with many obstacles, where shadowing from buildings can be avoided through
multi-hopping.
In summary, ODMA is a method to increase the capacity of a UMTS cell, not a
proper ad hoc networking method (all calls are finally routed to the base
station).

I would like to add, Robin, that operators such as KPN are actively
investigating the possibilities offered by ad hoc networking and that the
scenarios you sketch are not to be rejected just because they may threaten
our income. On the contrary, facilities to get cheap access to internet or
communicate cheaply between devices only increases the demand on mobile data
services...

One last question, Robin, could you maybe tell us about your background?
Which company or institution do you work for? I am always interested to
share ideas in this field.

Greetings,
Dirk.

------------------------------------------------------------------
Dirk Groten	      	             KPN  Research		
------------------------------------------------------------------	
P. O. Box 421		       Tel: +31 6 53747220
2260 AK Leidschendam	       Fax: +31 70 3326477
The Netherlands	             E-mail: [email-masked]

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From: Miguel Sanchez <[email-masked]>
Date: Tue, 30 Jan 2001 09:53:15 -0800

Hi Dirk,

I have recenlty learned  that Vodaphone is no longer interested in ODMA, so it
is out of 3G.

I think the idea can also be adapted for WLANs and it sounds like a good idea to
me (HIPERLAN standard includes something similar: Forwarding nodes). However
there are some MAC issues in 802.11 that  do not allow implementation based on
current standard (two different coordination functions).

Nice to learn that KPN is wise enough to consider this approach.

Regards,

Miguel

--
Miguel Sanchez

International Computer Science Institute
1947 Center St, suite 636
Berkeley, CA, 94704
USA

voice: (510) 666 2906
email: [email-masked]

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From: Saurabh Tewari <[email-masked]>
Date: Tue, 30 Jan 2001 19:00:58 -0600

> communicate cheaply between devices only increases the demand on mobile data

My first reaction to the original mail was that with this, operators would make
even more money i.e. there is no reason to give "83% of last sentence" free
even if it was in a fully-adhoc mode when you can charge for all of it. Operator

may pass on some infrastructure cost saving to the subscriber. I don't know if
I will believe an operator when he says my monthly bill is x as I was on adhoc
mode 20% of the time and not 50% of the time even if the operator decided to
bill based on the mode.

Can I, as a subscriber, know when I am in adhoc mode and when I am not?

Would I know if my phone/PDA is being used for someone else's transmission?

I am assuming that in future we'll be using same device for voice conversation
and internet access and that the same device will act as a router in the adhoc
network (is that a valid assumption?). Since I would like to receive calls, I
would
probably not turn off my phone and if I my phone can be a router and I cannot
tell if my phone is being used as a router, no one needs to compensate me for
my being cooperative in letting others use up my phone battery. Only thing I
can do is to not buy these dual-mode PDA-phones but then I won't be able to
get the cheaper rate either since my phone can never be in adhoc mode...

Saurabh

* Disclaimer - These are just my thoughts, not Alcatel's position/opinion on
this. *