Cell Relay Archive

[albert.e.manfredi@boeing.com]

In article <199802261706.JAA15904@thranduil.trillium.com.trillium.com>,
  rajeev@trillium.com (Rajeev Gupta) wrote:
>
> > From: albert.e.manfredi@boeing.com
> >
> > If each mobile station has a globally-unique MAC-like address (i.e. flat
> > space), then in principle, whenever such a station comes on line, it can
> > retrieve its temporary prefix (autoconfiguration) from the nearest
available
> > WATM switch.
>
> This would be equivalent to the temporary routing address to reach the
> mobile terminal at its current location.

Precisely so. But I really think that the ultimate solution is to make each
mobile unit a stand-alone unit, just as stationary hosts are. So I think the
real goal here is to make this temporary routing information available in
real time, as a permanent, global service.

> > As one moves about, the prefix assigned to your MAC-like address changes.
So
> > the trick is to have a sort of DNS-like network that keeps track, in real
> > time, of the mapping between all of these MAC-like unique addresses and
their
> > temporary prefix.
>
> The DNS-like network can be as simple as a single home location server
> for that mobile terminal and the current visited switch where the mobile
> is. The HLR keeps a mapping of the mobile's permanent address and it
> current temporary address (among other things).

The biggest problem with "home server" is that if I am traveling in
Keflavik, I sure as hell don't want someone from Helsinki have to call
me via a server in Johannesburg. I want to achieve a true mobile
capability, where calls are placed as efficiently as stationary unit
telephone calls.

Let's call this address lookup a Directory Service. The only problem I can
see, for a _global_ solution to mobile hosts, is that this temporary routing
that you mentioned will never settle down in time for units moving about. By
the time the mobile host in New Delhi has made its routing info available to
Seattle, the mobile host has possibly reached Bombay.

The answer is to have very few hosts maintain the mapping of mobile host flat
address to their entire, temporary hierarchical address. How? By using a
constellation of geosynchronous satellites ONLY to provide comms for this
Mobile Unit Directory Service. A few computers around the world could be kep
in synch pretty easily, I would think, if that's _all_ they have to do. And
the time lag is no big problem, since it only affects that first call setup.

> It is unlikely that there will be single network that will have to keep
> track of all mobile terminals. Usually, mobile terminals are associated
> with a home network (much like cellular networks).The home location
> registers in the home network keep track of the mobiles that belong
> to that network. All other networks/switches route calls for the
> mobile terminal towards the home network, just as they would any
> normal call. Note that the routing of the initial call is based on
> the mobile's directory number (not a name that needs to be resolved
> using DNS-like mechanisms). The home network, that recognizes the
> mobile's directory number, can then translate that into *another*
> routable (temporary) address to complete the call.

Rajeev, I really believe that the cellular phone "solution" is a kludge that
should be fixed. Don't you? To me, we should get past this "home network"
concept if possible. I think one should be able to:

1. Dial the unique, flat, address of a mobile unit, from anywhere on the
planet (request for mobile location could be identified with an AFI),

2. Have that request for mobile location (full, hierarchical, temp address)
routed to the closest earth-based uplink,

3. Have the request query a satellite-served mobile Directory Service,

4. Receive the full temorary address of that mobile unit,

5. And place the normal call, using the entire address, as any other call.

What do you think?

Bert
manfredi@arl.bna.boeing.com

-----== Posted via Deja News, The Leader in Internet Discussion ==-----
http://www.dejanews.com/   Now offering spam-free web-based newsreading