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Topic: State of Cell Phone Internet (as I see it) (Read 3 times) previous topic - next topic
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State of Cell Phone Internet (as I see it)
Yahoo Message Number: 19537
[You may want to skip this unless you are interested in the details of Internet over cellphones.]
 Those of us that want our Internet fix while on the road are caught in the middle of incompatible standards and evolving technology.  Maybe a little background will help.  Cellular service in North America got started with a system called "AMPS".  This is a simple system to send the voice signal over a cellular radio channel.  This is also what is called "analog" service.  In order to increase capacity, a new technology was introduced (somtimes called D-AMPS) which digitizes the sound and uses TDMA (Time Division Multiple Access) to carry up to three phone calls on each cellular channel.  Each call gets a sequence of time slices to send its data.  Later CDPD (Cellular Digital Packet Data) came along which offers real digital data capabilities.

Meanwhile over in Europe things took off in a different direction.
Over there a set of standards was developed for using a more complex way of sending digitized voice over a TDMA network.  These standards are known as GSM (Global System Mobile) and are used all over Europe.
Europe also uses different radio frequency allocations than North America.

At the same time, Qualcomm developed a completely different way of sending information over a digital cellular network called CDMA (Code Division Multiple Access).  While being even more complex, CDMA offers higher efficiencies using the limited radio spectrum.

Looking toward the future, all the major players have picked CDMA based technology for future, high speed services (3G).  But the GSM world is developing something called WCDMA and in North America, CDMA2000.
 Currently ATT probably has the largest network, but much if it is AMPS (analog) and large areas of D-AMPS.  To my knowledge, ATT does not offer any true digital data service on this network.  To get data over this network, requires using a modem to convert the data to "sound" and send it in analog mode over the cellular network to another modem.
And modems running over a cellular call can typically only manage a 4800-9600bit/sec connection.  To migrate towards the future, ATT has embraced GSM (since it is also based on a TDMA infrastructure) and is slowly rolling out a GSM "overlay" on its existing network.  One of the services available now on GSM networks is GPRS (General Packet Radio Services).  This offers true digital data service.  The problem is that D-AMPS and GSM require different phones.  Since GSM is still limited, most ATT phones are TDMA (D-AMPS).

Verizon and other CDMA carriers offer two modes for digital data.
Most (probably all) of the Verizon digital towers offer "circuit switched data".  This is what Verizon's Mobile Office product offers.
It essentially still places a "phone call", but the network is aware that the call is carrying data.  Verizon bills these calls like any other cellular calls which use up plan minutes.  This service is limited to a 14.4kbit/sec data rate. Verizon provides their own Internet access by calling #777, or you can call your own ISP's access numbers.  More recently, Verizon has started rolling out phase one of their CDMA2000 plan.  They sell this as their "Express Network" service.  Since this is a new technology, it is only supported by the newest phones (and a couple of PC Card devices).  This (like GPRS) is a pure data service and is billed by data traffic amount.  The 1xRTT protocol used in Express Network can run up to 144kbit/sec, though typical useage is reportedly more in the 30-50kbit/sec range.
 Most newer cell phones can offer access to any digital data services using only a data cable to connect it to the laptop (either via a serial port, or increasingly via a USB port).  But out in a rural area where only analog service is available, these do no good.  This is where the Ositech cards are good for RV travelers.  With the correct phone, they will use digital service if available, or automatically switch to modem-over-analog if that is all that is available.  The down side is that Ositech only supports a very limited number of phone models and don't create new products as fast as the phones are coming out.

IMO, the Verzon network currently provides the best digital data service, but in rural areas ATT may have more analog coverage.  With the Verizon National Single Rate plan, I can get Verizon's digital service where available, and roam onto ATT's analog network without cost if I need to.

Hope this of interest to someone, Art
Art and Barbara
Settled in Atterdag Village of Solvang
2015-2022 fulltime in a 2016 Tiffin Allegro Bus 37AP
2002-2015 2002 LD MB
Art's blog
Re: State of Cell Phone Internet (as I see it)
Reply #1 –
Yahoo Message Number: 19540
This someone is very interested.  Thanks for the info, Art.  Your last sentence certainly caught my eye.  Is that as good as it sounds or is there a catch? Steve T

With
Re: State of Cell Phone Internet (as I see it)
Reply #2 –
Yahoo Message Number: 19541
Quote
IMO, the Verzon network currently provides the best digital data service, but in rural areas ATT may have more analog coverage.  With the Verizon National Single Rate plan, I can get Verizon's digital service where available, and roam onto ATT's analog network without cost if I need to.

Hope this of interest to someone, Art
Also of great interest to me, Art.  Thanks to you and others who responded to my Internet/AT&T/Motorola set-up questions.  I now wish I had investigated the cellphone capability before I bought it.

Chris Horst
Formerly: 2002 30' IB
Re: State of Cell Phone Internet (as I see it)
Reply #3 –
Yahoo Message Number: 19542
---> IMO, the Verzon network currently provides the best digital data
 
Quote
service, but in rural areas ATT may have more analog coverage.  With the Verizon National Single Rate plan, I can get Verizon's digital service where available, and roam onto ATT's analog network without cost if I need to.
Good analysis and I too having been using the Verizon National Single Rate plan for the last two years. Very Satisfied!

Tom
Re: State of Cell Phone Internet (as I see it)
Reply #4 –
Yahoo Message Number: 19543
Quote
This someone is very interested.  Thanks for the info, Art.  Your last sentence certainly caught my eye.  Is that as good as it sounds or is there a catch? Steve T
Well the two biggest catches I can think of are these.

First, the NSR plan costs more for a certain number of plan minutes than their Americas Choice plan.  Also, they only offer extra weekend minutes with NSR, no nighttime minutes and certainly no unlimited N&W options.  But we are often in areas without cell service, much less Verizon or their extended network.  If I can get any service, I don't want to worry about roaming charges.

Second, the PRL (Preferred Roaming List) in the phone will favor Verizon or the extended network partners, even if that signal is weaker than others available.  This can mean the phone always attempting to place a call with a tower than provides too weak a signal for a reliable data connection.

Art
Art and Barbara
Settled in Atterdag Village of Solvang
2015-2022 fulltime in a 2016 Tiffin Allegro Bus 37AP
2002-2015 2002 LD MB
Art's blog
Re: State of Cell Phone Internet (as I see it)
Reply #5 –
Yahoo Message Number: 19544
Can the PRL be modified?  I think I recall some mention of that in some form on this forum a while back.
Steve T
Re: State of Cell Phone Internet (as I see it)
Reply #6 –
Yahoo Message Number: 19551
Quote
Can the PRL be modified?  I think I recall some mention of that in some form on this forum a while back.
I don't know if the hard core phone hackers can put customized PRLs into their phones, but what many people do is to just not update theirs.  It is currently a user initiated operation to load the newest PRL into your phone (you have to do this in your "home" area).  If you like the coverage you have based on the old PRL, just don't change it.
This preserves the coverage you have, but has a couple of potential downsides.
First, a network in the old PRL may no longer be part of the extended network and depending on your plan may become subject to roaming fees (though it appears Verizon has been very lenient when it comes to roaming with ex-partners).  Second, the phone may be inhibited from roaming onto a new partner and instead continue to roam on a network that has always charged roaming.

Art
Art and Barbara
Settled in Atterdag Village of Solvang
2015-2022 fulltime in a 2016 Tiffin Allegro Bus 37AP
2002-2015 2002 LD MB
Art's blog