Grant wrote: >>>>> Nice, I'm very glad to hear it works so well. I guess >>>>> something like that would work even over an analog connection. >>>>> >>>> On a true analog (800MHz AMPS service) cell phone, I've had >>>> pretty decent success using MNP5 modems up to about 2400 baud. >>>> The standard CCITT error dectection/correction schemes used on >>>> landline modems isn't resilient enough for RF links. Good luck >>>> finding MNP5 analog modems. ;) Multitech in St. Paul was the >>>> last vendor I knew about that sold them, and that was 10+ >>>> years ago. >>>> >>>> If you're talking about an analog connection to a digital >>>> phone, it just won't work. The Codecs that digital phones use >>>> are optimized for human speech and won't pass QPSK (or even >>>> FSK) modem signals in a usable manner. >>>> >>> What I meant there was that I should be able to dial up in >>> this manner even if the signal is reported to be analog >>> instead of digital. Is that true? >>> >> I still don't understand what you're asking. Unless you're >> 800MHz AMPS service, it's all digital. There is no analog >> signalling on the network. >> >> If you're using an 800MHz AMPS service, then the "voice" >> channel is an analog FM link band-limited to 300-3KHz with C >> message weighting (just like a landline phone connection). You >> can push an analog modem signal through that voice channel, but >> the channel quality varies a lot and you need a really >> bullet-proof error-correction scheme like MNP5. >> > > What I'm trying to determine is, if AT&T or T-Mobile have the type of > service you're describing: > > 1. will it work in both "analog" and "digital" service areas > 2. does the phone need to support anything in particular to use it > > >>> Are you saying it depends on whether or not the phone is >>> capable of 800MHz AMPS service? >>> >> I guess so. The carriers are going to shut down AMPS service >> soon anyway. >> >> >>>> It's just passing on digital data that's carried by the >>>> wireless protocol in use (GSM/TDMA or 1xRTT/CDMA). When you >>>> "dial up a landline" with a digital cell phone, the wireless >>>> carrier actually has to connect a modem to a landline at the >>>> carriers switch and dial the number. The digital data from the >>>> cellphone is then routed to that modem. >>>> >>>> If you're using the wireless carrier as the ISP, then there are >>>> no modems involved at all: the digital data from the modem is >>>> simply routed onto the Internet. >>>> >>> I see. So the only ways you know of to get a laptop online >>> with a cell phone are with a data plan in a digital service >>> area, or with any Verizon plan in either an analog or digital >>> service area? >>> >> If you're using analog service, you can use any carrier that >> allows normal phone calls to access a dial-up modem. You just >> need a phone with a phone jack into which you can plug an >> analog modem. Motorol "bag" style phones used to have a >> accessor that plugged between the handset and the radio which >> provided a modem jack. I don't think you're going to find too >> many current phones that provide an analog modem jack. >> > > I don't think I'll have any luck finding a cell phone with an analog > modem jack. Were you using an analog modem plugged into your cell > phone with the service you were first describing? > > >> Sprint also apparently has a free low-speed Internet access >> service similar to Verizon's "QNC" service. I don't know if >> Sprint's free low-speed service allows you dial up a >> landline-modem or not. >> >> FWIW, I just plugged my VX4400 into my laptop, and Verizons >> low-speed QNC service is still working. There are rumors >> that Verizon is about to pull the plug on QNC, but those rumors >> have been around for years. >> > > I've got to go with GSM. If both Sprint and Verizon offer it, there > is probably a good chance that AT&T and/or T-Mobile do too. > Neither Sprint nor Verizon offer GSM, they use CDMA, thus you can't travel anywhere (that I know of) with those phones. If you are looking for a "world phone", get a quad-band GSM phone, Cingular/AT&T or T-Mobile carries them in the US, in Europe everyone carries them.
-Gabriel > - Grant > -- [EMAIL PROTECTED] mailing list
