Subject: RE: [seamoby] draft-ietf-seamoby-paging-problem-statement-02.txt

From: Kulwinder Atwal <[email-masked]>
Date: Sat, 24 Feb 2001 01:14:05 -0500

> -----Original Message-----
> From: James Kempf [mailto:[email-masked]]
> Sent: Friday, February 23, 2001 7:36 PM
> To: [email-masked]; [email-masked]
> Subject: Re: [seamoby]
> draft-ietf-seamoby-paging-problem-statement-02.txt
> 
> 
> Hi Erik,
> 
> >A minor aspect of the problem statement that I hadn't thought about
> >earlier.
> >
> >Why are we restricting the problem of paging to a single last hop?
> >* There could be several IP hops after the mobile link (e.g. a home
> >network)
> >* It is an architectural decision where to implement the paging
> >functionality.
> >
> >The current problem statement assumes it must be in the last 
> hop router.
> >It could also be in an IPv4 FA, distributed in a set of 
> routers (ties in
> >to micromobility)
> >or a hierarchical MIP entity (I forget the acronym used).
> >
> >I propose we remove "last hop" from the definition of paging. 
> 
> Well, the kinds of networks that do paging typically have a last hop
> that is a radio link and I think that is why last hop is there. Paging
> is typically only done over the last hop at L2, and, as the draft
> explains, those are the only kinds of networks that would need any
> L3 paging support.

Bluetooth has L2 support for paging, and there is nothing "typical" about
it.

> 
> 
> So I have some amount of difficulty seeing what removing last 
> hop would
> add to the problem statement, unless there is a case I am missing.
>

I believe we are also restricting the possibility of a mobile router.
For example, a train, car, ship, acting as mobile router containing
laptops/PDAs acting as mobile routers for a headset.  There maybe several
wireless hops:

CASE 1:
- satillite to ship's ANG.
- a shipboard Access Point to Laptop.
- Laptop to PDA.
- PDA to headset

CASE 2:
- Cell tower to train's ANG.
- a train mounted Access Point to Laptop.
- Laptop to PDA.
- PDA to headset.

CASE 3:
- Marine radio network to boat's Mobile Router.
- boat's Access Point to Laptop.
- Laptop to PDA.
- PDA to headset.

CASE 4:
- Cell tower to car's Mobile Router.
- Car's Access Point to Laptop.
- Laptop to PDA.
- PDA to headset.

CASE 5:
- Private Radio tower to car's Mobile Router (Taxi, Police, Ambulance,
Courier Service).
- Car's Access Point to Laptop.
- Laptop to PDA.
- PDA to headset.

CASE 6:
- Satillite to long haul truck's Mobile Router.
- Truck's Access Point to Laptop.
- Laptop to PDA.
- PDA to headset.

CASE 7:
- Cell Tower to Laptop carried by mobile user walking/riding bike.
- Laptop to PDA.
- PDA to headset.

CASE 8:
- Bluetooth/802.11 Access Point on Company premises or at home, to Laptop
carried by mobile user.
- Laptop to PDA.
- PDA to headset.

If we only allow single hops then we are restricting the protocol primarily
to the "typical" case of a commerical cellular tower to cell phone, and
ruling out all kinds of other wireless networks.

- Kulwinder.
 
> 		jak