Re: PPC modem
From: Almon B. Strowger (strowger_at_NOSPAM.kook.com)
Date: 09/14/04
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Date: Mon, 13 Sep 2004 18:33:37 -0700
Hi,
Thanks for the info. I'll check out the website.
I'm not an OEM now, but hey--Maybe I'll
reconsider that given the new opportunities.
BTW--How CPU intensive is the soft modem
on CE--Can it work with, say older Pocket
PC 2000 models?
Almon B. Strowger
KOOK Pocket Software
"darrin Garrett" <dgarrett@airbiquity.com> wrote in message
news:41463261.2010000@airbiquity.com...
> No not a regular PC modem, but a C++ library that interfaces to an
> Application and also the audio device in the system, basically a soft
> modem but runs in the application program memory, not a device driver.
>
> 4.8k CELP definitely not, I don't know of any digital cell networks that
> still use this. VSELP is only used on TDMA and GSM (Europe) and at full
> rate on TDMA it works. It also works on the following:
> ACELP, AMR (12.2k-7.4k), QCELP13K and EVRC (our modulation scheme forces
> them into full rate, and EVRC is the most widely deployed vocoder in the
> US), and SMV full rate only. Most of these have been tested with the
> bit exact code as well as bench and drive tested across the US and Canada.
>
> The effective data throughput is very low with our retry scheme and
> acknowledged service delivery about 110 baud even though its a 400 baud
> modem. This is do to the fact that the protocol is designed to work in
> CDMA and EVCR which is the worst in terms of cellular network signaling.
> This is good enough to get for example all of the following: GPS,
> vehicle ID, Air bag deploy(vehicle state), user ID and security key
> within 1.4 seconds.
>
> As far as OnStar is concerned, we are under contract not to say any
> thing in the form of a press release or advertise our relationship with
> out their consent, so I would have to say no.
>
> We do have the modem ported to various DSPs as well but why go there.
> They are not sold in retail form as of yet, hopefully soon because I am
> actively working on that. If you are an OEM then this is something we
> could do now.
>
> www.airbiquity.com
>
> Almon B. Strowger wrote:
> > Hi,
> >
> > Excellent--I thought you meant using a regular PC modem.
> > Or did you? (Thinking of a different product.)
> > (Now you'll tell me that there are some standard modems
> > that you reflash the DSP code to make them work, right? :)
> > I can think of some uses for it even at the slow rate.
> > So what's the typical data throughput (given that you have
> > CRC and ECC)?
> > Do you sell them retail? Website? So it's your modem
> > that is used in OnStar?
> > So can you still get pretty consistently correctable data
> > with the 'worst' (most highly voice optimized) vocoders?
> > Can it work with 4.8k CELP? Or is 8k VSELP its limit?
> >
> > Almon B. Strowger
> > KOOK Pocket Software
> >
> >
> > "darrin Garrett" <dgarrett@airbiquity.com> wrote in message
> > news:4145D067.605@airbiquity.com...
> >
> >>It seems like you know a thing or two about modems. The reason I
> >>originally posted this question was to see if there were any
> >>alternatives to the modem that we make here at my work, and I have not
> >>found any yet. Any constant FSK frequency (which is required for TX/RX
> >>synchronization for Bell and V. modem) will be filtered out by both
> >>noise cancellation software in the cell phone and cellular network
> >>Vocoders. Not only that, the cell tower to phone signaling (iDEN,
> >>TDMA, CDMA, and a little bit with GSM) removes audio and inserts control
> >>info like power adjustment, cell tower handoff info, and other stuff.
> >>When this happens bits are corrupted, so Bell 103 wont work at any
> >>frequency. What we have is a full duplex send and receive modem with
> >>forward error correction, CRC, retry and acknowledgement, and we make
> >>the frequency look like voice to the cellular network. It’s a 400 baud
> >>modem so only applications like telematics (GPS/location services,
> >>vehicle diagnostics, asset tracking, telemetry…) would make sense. No
> >>more monthly data service, and yes it has been ported to WinCE and PPC.
> >>
> >>
> >>Almon B. Strowger wrote:
> >>
> >>>Hi,
> >>>
> >>> Well then you have your own answer regarding
> >>>a typical PC modem. Do BOTH Bell 103 and V.21
> >>>fail to work? And do they fail in BOTH directions?
> >>>(Some modems can be told to turn off / ignore carrier.)
> >>>If you use choose a modem that can be tweaked, or one
> >>>that can go into TTY/TDD mode (look for V.18), then
> >>>you may have something--But you may be stuck with
> >>>45.45, 50, 75, or 110 baud (Also check out Ultratec
> >>>turbo code.) If the standard 300 baud full duplex modem
> >>>frequencies won't work, the TTY frequencies of 1400Hz
> >>>and 1800Hz might. (You may end up being forced into
> >>>half-duplex mode.) Also, since it is carrier-less, it may be
> >>>more robust for cell phone use. Have you looked into
> >>>using V.23 at the 600 bps rate? (I'd be surprised if this
> >>>worked anywhere, but hey...) But anyway, if you do
> >>>use modems for the PC end that have V.18, you will be
> >>>able to get something to work--Not sure if the data rate
> >>>will be acceptable to you though.
> >>>
> >>>Hope this helps...
> >>>
> >>>Almon B. Strowger
> >>>KOOK Pocket Software
> >>>
> >>>P.S. By the way...Did you have a specific application
> >>>in mind, or is it just the general idea of sending data
> >>>over the voice channel to save money?
> >>>
> >>>
> >>>"darrin Garrett" <dgarrett@airbiquity.com> wrote in message
> >>>news:4141D26C.1030400@airbiquity.com...
> >>>
> >>>
> >>>>Well, I know 300 baud will not work, that is what Onstar ( of General
> >>>>Motors) used for their data comm to the car but had to switch to a
> >>>>different modem when they switched from AMPS to digital embedded cell
> >>>>phone in the car. The Vocoders in the digital networks filter out the
> >>>>300 baud modem tones. I know what they are using but I can not
> >>>>advertise this, but I can tell you it is a special modulation/protocol
> >>>>scheme, one of a kind.
> >>>>
> >>>>Almon B. Strowger wrote:
> >>>>
> >>>>
> >>>>
> >>>>>Hi,
> >>>>>
> >>>>>So, to avoid digital charges, and since AMPS is going extinct,
> >>>>>you want to see if an old-style 300 baud modem will work
> >>>>>with the various vocoder schemes? In your original post, did
> >>>>>you mean the desktop PC / server would be using a typical
> >>>>>standard modem? If so, all you can get is 300 baud, if anything.
> >>>>>I'd suggest patching in a real modem to the cell phone first.
> >>>>>(using 300 baud) to see if it's feasible first.
> >>>>>
> >>>>>Hope this helps...
> >>>>>
> >>>>>Almon B. Strowger
> >>>>>KOOK Pocket Software
> >>>>>
> >>>>>
> >>>>>"darrin Garrett" <dgarrett@airbiquity.com> wrote in message
> >>>>>news:413E44F1.8040903@airbiquity.com...
> >>>>>
> >>>>>
> >>>>>
> >>>>>>Interesting,
> >>>>>>I thought that if you were to use the voice channel that today’s
> >>>>>>cellular vocoders (CDMA, GSM) would not allow a modem to work. Are
> >
> > you
> >
> >>>>>>sure you are not going through the control/data channel and not the
> >>>>>>voice channel. You can test this by using your "external modem"
cell
> >>>>>>phone and calling another phone. When you answer with the other
phone
> >>>>>>listen to see if you can hear any modem tones.... like you would if
> >
> > you
> >
> >>>>>>were calling out with a land line V.90 modem in a PC.
> >>>>>>
> >>>>>>
> >>>>>>David Gonzales [MS] wrote:
> >>>>>>
> >>>>>>
> >>>>>>
> >>>>>>>Windows Mobile does not support USB Host. However, a few Pocket PCs
> >>>
> >>>have
> >>>
> >>>
> >>>>>a
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>custom implementation of it (i.e. the manufacturer has added their
> >
> > own
> >
> >>>>>>>support for USB Host).
> >>>>>>>
> >>>>>>>Also, modem functionality is not a part of Pocket PC (i.e. the
Pocket
> >>>
> >>>PC
> >>>
> >>>
> >>>>>>>acts as a modem peripheral for a desktop PC), but again some
> >>>>>
> >>>>>manufacturers
> >>>>>
> >>>>>
> >>>>>
> >>>>>>>have added modem feature to thier Pocket PC Phone Edition device.
> >>>>>>>
> >>>>>>>Any Pocket PC should be able to use an IR-enabled cell phone as a
> >>>
> >>>modem.
> >>>
> >>>
> >>>>>>>David
> >>>>>>>------
> >>>>>>>This posting is provided "AS IS" with no warranties, and confers no
> >>>>>
> >>>>>rights.
> >>>>>
> >>>>>
> >>>>>
> >>>>>>><r_z_aret@pen_fact.com> wrote in message
> >>>>>>>news:dqmjj05qejenvv65a46po564m15il9qe6n@4ax.com...
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>
> >>>>>>>>I have a Motorola StarTac cell phone (> 2 years old) that includes
> >>>>>>>>some sort of modem. I bought a serial data cable, and now the cell
> >>>>>>>>phone "looks" like an external modem. It works with any software
> >
> > that
> >
> >>>>>>>>supports external modems. I've used it with a laptop (Win 98) and
> >
> > with
> >
> >>>>>>>>an HPC Pro (version 2.11 of the Windows CE operating system). No
> >>>>>>>>special driver needed. No special program. No data service needed
> >
> > from
> >
> >>>>>>>>my cell phone carrier. Top speed is only 19.2K, but that is better
> >>>>>>>>than 0. I _think_ newer phones can do something similar with USB,
> >
> > but
> >
> >>>>>>>>that would require at least USB host support, which isn't
available
> >>>>>>>>for older Windows CE devices (I _think_ it is supported for Pocket
> >
> > PC
> >
> >>>>>>>>2003).
> >>>>>
> >>>>>
> >>>>>
> >>>
> >
> >
>
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