Subject: Re: IrDA?
To: Pete Bentley <peter.bentley@nomura.co.uk>
From: Jukka Marin <jmarin@pyy.jmp.fi>
List: current-users
Date: 01/28/1999 15:56:18
On Thu, Jan 28, 1999 at 11:30:14AM +0000, Pete Bentley wrote:
> augustss@cs.chalmers.se wrote:
> > > The prices of Nokia 6150 GSM phones are dropping and.. and.. :-)
> > But does it speak IrDA?
> 
> I don't believe it does. According to one source[*] the 6110, 6150, 8110
> and nk702 all require Nokia software.  The Nokia 8810, Ericsson SH888 &
> DI27 all talk IrDA though (IrCOM).

Hmh.. Well, it _had_ to had something wrong with it.. it looks like a nice
toy, but if there's no hope of using it with non-m$ systems.. well.. :-(

> Indeed, although I think some of the timings are a bit tight, so a
> user-level implementation might run slow if it drops packets and
> requires retransmits. 

Well, don't the UART chips buffer the incoming data as always (when an
UART is involved, like in my case)?  Maybe this isn't enough (haven't
studied the IrDA specs too closely - just enough to notice that the
protocol was pretty complex when all you wanted to do was to transfer
bytes from device A to device B (which I am doing using my own protocol
now)).

> On the other hand, given the complexity of the protocols I think the
> free Unix community would benefit from a portable, user-space IrDA stack
> or some sort (perhaps just a daemon that created a mapping from certain
> TCP ports to certain IrDA service end-points).

That would be nice and I guess there would be many users for this stack
outside the NetBSD community, too.

> As far as I know the
> Linux people are going for a kernel implementation, so that's not going
> to be much use to anyone else.

That's how it seems.

> I did make a start on such a thing about 2 years ago, but was hampered
> by the hardware I was using (SS10 + serial IrDA dongle, talking to a
> Psion 3c which doesn't exactly have the best IrDA stack in the world
> anyway) and eventually ran out of time...

Hm..

> I guess the reason no-one else has bothered either is the complexity. 
> To get a simple serial stream from one computer to another you have to
> implement at least 4 layers:-
> * A hardware 'driver' layer to program whatever serial to IR device
> you're using

This is simple when you're using something like the Tekram IrMate 210
(an external IrDA transceiver that connects to a standard serial port).

> * IrLAP - Link access, neighbour discovery, datagram layer
> * IrMUX - Service discovery and connection, "stream" layer
> * IrComm - Serial line emulation over IrMUX

These are the hard part.. ;-) :-(

> IrDA is truly a protocol suite that has suffered badly from being
> designed by a committee...

YES! :-(

> but I still think it would be a cool thing to implement under Unix.

Yes. :-)

> With the rise of IrDA compliant ports on PDAs, phones and printers,
> there are potentially a lot of cool applications (plonk your phone or
> PDA on the desk next to you workstation and it just hot-syncs[**]
> automagically).

Anyone got some extra time they could sell me for cheap?  Something like
10 years or so, delivered next week?

  -jm

On Thu, Jan 28, 1999 at 01:33:35PM +0100, Markus Illenseer wrote:
> 
>  Have a look at this: http://fsinfo.cs.uni-sb.de/~columbus/lirc
> (Yes, Linux, but who cares)

Hmm, the remote controls (and lirc, afaik) use their own simple "protocol",
which has nothing to do with IrDA (except that the same hardware can usually
be used for both).

>  To my knowledge, only the Nokia 8810 (awfully small for my fingers :-) and Ericsson
> SH888 are capable of IrDA and includes a build-in modem. The other mobiles require 
> specific (Windows) software.

Bummer. :-(  There goes my "good reason" for getting a 6150 ;-) :-(

  -jm