Posted as <http://navasgroup.com/tech/sch-8500/>.
NOTE: This information was compiled by the author and is provided as a public service. The author has no connection to Sprint or Samsung except as a customer. The author is not responsible for any errors or omissions, or for any consequential problems that might result. USE AT YOUR OWN RISK.
Email comments and suggestions to John Navas.
The following procedure should enable you to make data connections over
Sprint PCS with a Samsung SCH-8500
phone using a Windows 95/98/ME computer
(e.g., IBM ThinkPad
600 notebook). The descriptions
below assume Windows 98 Second Edition, but the process is similar
for Windows 95/ME.
(You may also be able to adapt these procedures for other Sprint PCS phones
and/or other operating systems.)
If available, you might want to sign up for the initial free months promotion of Sprint
PCS Wireless Web to avoid paying US$0.39/minute for data calls (as of this
writing). To further keep costs down
you should be able to buy a bare data cable direct from
Samsung (888-987-4357) for US$50, rather than pay Sprint US$100 for
the Sprint PCS Wireless Web Connection,
which is just the cable and some user-friendly software that you don't really
need. The Samsung data cable
connects easily to a standard notebook computer DB-9 serial port and
the SCH-8500 phone.
Start by using the following procedure to create a modem entry for the Samsung SCH-8500:
That installs the modem, and should take you back to Modem Properties, which should be closed with OK, followed by closing the Control Panel.
Acknowledgement: Thanks to Bob George for figuring out how to access Sprint PCS QNC!
There are three ways to make a data connection:
To create a DUN (Dial-Up Networking) Connection entry for QNC:
It's important to configure the new Connection. Right-click the new Connection in the DUN window, select Properties, and proceed as follows:
There are three ways to make a data connection:
To create a DUN (Dial-Up Networking) Connection entry for a standard dial-up ISP (e.g., Earthlink):
It's important to configure the new Connection. Right-click the new Connection in the Dial-Up Networking window, select Properties, and proceed as follows:
To make a data connection to QNC or to your ISP:
If everything is set up and working properly, you should first see "Status:
Dialing...", then "Status: Verifying user name and password...", followed by a completed connection.
The SCH-8500 enters data mode automatically when it detects the dial out command from your computer. (Manually setting the phone to "Data/Fax In" mode is only necessary on
incoming data or fax calls.) When in data mode, the SCH-8500 has an informative display of what's going on, both when dialing, and when
connected:
00:00:00 Data @ 14.4 Rec Trx 999-999-9999 |
« duration of connection « data rate « receive and transmit indicators « phone number |
Dark blocks appear to the right of "Rec" and "Trx" when the phone is receiving or transmitting data, respectively, much like a regular external modem.
Don't forget to disconnect the Connection (in your computer) when you're
done or even when not using it for more than a minute or two so as not to waste
air time. (When you disconnect with the computer, the phone should end the
data connection automatically, but check to be sure.)
There are three ways to make a data connection:
Sprint PCS can also be used to make data connections to dial-up services other than the Internet; e.g., so-called bulletin board systems. How to do it depends on the particular communications program. Here is a sample connection to the NIST (National Institute of Standards and Technology) Time Service using HyperTerminal Private Edition (free upgrade to HyperTerminal, downloadable from Hilgraeve):
The SCH-8500 enters data mode automatically when it detects the dial out command from your computer. (Manually setting the phone to "Data/Fax In" mode is only necessary on
incoming data or fax calls.) When in data mode, the SCH-8500 has an informative display of what's going on, both when dialing, and when
connected:
00:00:00 Data @ 14.4 Rec Trx 999-999-9999 |
« duration of connection « data rate « receive and transmit indicators « phone number |
Dark blocks appear to the right of "Rec" and "Trx" when the phone is receiving or transmitting data, respectively, much like a regular external modem.
Don't forget to disconnect the Connection (in your computer) when you're done or even when not using it for more than a minute or two so as not to waste air time. (When you disconnect with the computer, the phone should end the data connection automatically, but check to be sure.)
Latency is pretty bad (even on QNC), many times greater than a dial-up modem connection,
and even worse than a geosynchronous satellite link. Here's an example:
>tracert www.cisco.com Tracing route to www.cisco.com [198.133.219.25] over a maximum of 30 hops: 1 1064 ms 878 ms 899 ms tnt2.wnck11.pbi.net [206.13.11.10] 2 922 ms 918 ms 999 ms pop1-e02.wnck11.pbi.net [206.13.11.9] 3 1035 ms 899 ms 1098 ms core1-a0-0s1.snfc21.pbi.net [206.171.128.177] 4 912 ms 899 ms 1098 ms edge1-ge1-0.snfc21.pbi.net [209.232.130.20] 5 894 ms 998 ms 919 ms sfra1sr3-so-1-1-0-0.ca.us.prserv.net [165.87.161.6] 6 1051 ms 1094 ms 899 ms sfra1br1-ge-1-2-0-0.ca.us.prserv.net [165.87.33.120] 7 928 ms 918 ms 879 ms 165.87.161.201 8 974 ms 899 ms 999 ms 175.at-6-0-0.XR2.SAC1.ALTER.NET [152.63.50.190] 9 904 ms 1058 ms 937 ms 184.ATM7-0.XR2.SJC1.ALTER.NET [152.63.50.82] 10 845 ms 899 ms 2596 ms 192.ATM5-0.GW8.SJC2.ALTER.NET [152.63.49.225] 11 911 ms 999 ms 999 ms cisco.customer.alter.net [157.130.200.30] 12 887 ms 900 ms 996 ms 192.150.47.2 13 914 ms 1017 ms 1198 ms www.cisco.com [198.133.219.25] Trace complete. |
Throughput can be erratic and poor (as measured by FTP download
tests). Although a 14.4 bps connection should be able to sustain
over 1500 cps (characters per second), your speed may fluctuate all over the place, with an average of only about
half that (i.e., 750 cps). To the right is a record of a
relatively good session (at 9:45 AM).
You should be able to surf the web with your computer, and the phone should maintain the data connection. Large pages will of course load more slowly than a regular modem connection. You can speed page loading by:
You should also be able to use all other Internet protocols; e.g., receiving and sending email at your dial-up ISP, accessing Usenet newsgroups, FTP file transfers, ICQ, etc.
No protocol errors should be reported in either PPP or modem logs.
Sprint touts speed "comparable to landline dial-up access of 56.6 kbps" as part of "Sprint PCS Wireless Web for Business" as introduced in August 2000. (See "Sprint Introduces Sprint PCS Wireless Web for Business")
However, this does not appear to really be "comparable to landline dial-up access of 56.6 kbps"
as most people would understand it (e.g., a V.90
dial-up modem) -- it appears to be just data compression
(e.g., V.42bis)
on the existing 14.4 Kbps data service. The key words from Sprint are
"up to" -- 56 Kbps could only be achieved with 4:1
compression, which is very rare in practice (outside of synthetic benchmarks). Based on dial-up modem
performance data, typical compression will rarely exceed 2:1, for a maximum speed of about 28.8
Kbps.
At best this would bring Sprint PCS up to par with old 14.4 Kbps V.32bis
dial-up modems, not current 56K V.90 dial-up modems. In practice
Sprint PCS will still probably be much slower than even 14.4 Kbps V.32bis
(much less V.90) -- Sprint PCS hasn't been able to stream data at anywhere near its rated speed. (See
"The Experience")
To really get respectable data speed, it looks like we'll have to wait for the future.
Currently the data connection a digital link from your computer over the air to Sprint PCS and then by wired digital network to a Sprint PCS out-dial based on conventional modem technology. The Sprint PCS out-dial modem dials and makes a standard analog modem connection. Data must transit both an air link and an analog modem link in both directions, which is at least part of the reason for the high latency (even on QNC).
This works, but is clearly a painful kludge. Something better is needed as wireless networks evolve toward higher speeds and IMT-2000/UMTS/3G.
Accessories
Palm connectivity
Stupid Palm Tricks
by Bob George
(Using a Palm with Sprint PCS QNC service)
Syncable Solutions (cables and adapters)
The Sprint Data Connection Kit (review)
Services
Samsung
Software
TELUS Mobility (better documentation than Sprint PCS)
This section on commands that can be used to control and program the SCH-8500 through the data cable interface was prepared by Mike Milner:
Samsung is not forthcoming with information on the command structure(s) for its CDMA cellphones like the SCH-8500. Unlike GSM cellphones, where commands are specified in a publicly available standard, each CDMA vendor seems to roll its own. As far as I can determine, Samsung uses a subset of V.250 for its AT commands, and a packet-based link-level protocol for low-level access to the memory space of the cellphone. I've found the following AT commands work on my SCH-8500:
Command Function ate[0|1]
atm[0-3]
atq[0|1]
atv[0|1]
atx4
at&c1
at&d2
ats7=60
at+cad?
at+cbc?
at+csq?
at+gcap
at+gmi
at+gmm
at+gmr
at+cfc=0
at+crm=0
at+cdv
at+chv
at+crc?
at+gsncommand echo [off|on]
speaker level
return results code [on|off]
display results codes as [codes|words]
enable additional result codes
carrier detect - follow input
enter command mode on CD on » off
time out if not connected
service type (analog, CDMA)
battery level
signal level
list capabilities of cellphone
cellphone manufacturer
cellphone model
cellphone firmware version
set Um interface fax compression - none
set Rm interface protocol - asynch fax/da
dial following digits as a voice call
hang up a voice call
extended results codes
appears to be an ESNSo far I've found no AT commands that manipulate the internal phone book or provide access to SMS messages. What little I've seen of the lower level protocol suggests that accessing the phone book and/or SMS is done using the cellphone equivalent of "Peek" and "Poke" commands where knowledge of the internal representation of the data being accessed is in an external application driving the serial link to the cellphone. The cellphone just returns the contents of whatever address is requested - no fancy business that might distract the cellphone from its prime directive. The first binary exchange from the application to the cellphone, after AT commands have identified the cellphone as a SCH-8500, is "7F AA DD 7E", repeated 3 times. Subsequent packets always start with "7F" and end with "7E" - flags that look a bit like a LAPB or LAPD ("7E" on both ends). In the Qualcomm DMSS software description, this service seems to be called SURF-PST and is closely related to CAIT. Lacking a Rosetta Stone, that's all I can figure for now.
Given the cost/performance/power budget the cellphones are designed to, my feelings are that a higher level interface/API isn't likely, whereas the lower level interface potentially exposes too much of the cellphone's internals for comfort, leaving vendors unwilling to share the details a programmer would assume are openly available.
Mike welcomes contributions, particularly any information on reading and writing phone book entries, calendar entries, and/or SMS text. He'd particularly like somebody who recognizes the flag bytes in the binary protocol to point him toward some details in that area.
Additional commands contributed by Eric Sandeen:
Command | Function |
AT+IPR=n AT+GMI AT+GMM AT+GMR AT+GSN AT#PMODE=n |
set serial interface to n bps
(where n is a speed returned by "AT+IPR=?") get manufacturer (e.g., ) get product ID (e.g., SCH8500) get firmware (e.g., ) get serial number (e.g., ) (0-1) Program Mode? (e.g., 0 » off, 1 » on) |
Program Mode Command |
Function (must set AT#PMODE=1) |
AT#PBOKR=n AT#PBOKW=n,DATA AT#PCOUT? |
get phone book location (1-229) set phone book location (1-229); see below for DATA (0-1) ? |
AT#PBOKR Command (must set AT#PMODE=1 to use)
DATA » NAME,RINGERTYPE,ENTRY[,ENTRY...]
NAME » name in double quotes (e.g., "John Doe", "Doe,John")
RINGERTYPE » 0-12 (0 » Ring 1, 8 » Ring 9, 9-12 » melodies)ENTRY » LABEL,NUMBER (one to six)
LABEL » 1-6 (1 » home, 2 » work, 3 » mobile, 4 » pager, 5 » fax, 6 » no label)
NUMBER » (1-32 characters from the set [0123456789*#pT]; first ENTRY sets speed dial)Example: 5,"Doe,John",3,2,8005551212,1,8885551212
(Location 5, "Doe,John", Ring 4 [3], work number 8005551212 [speed dial], home number 8885551212)
Additional, undocumented commands contributed by Rick Kunz:
Command | Response |
AT&F AT+CAD=? AT+CAD? AT+CBC=? AT+CBC? AT+CBIP? AT+CDR=? AT+CDR? AT+CDS=? AT+CDS? AT+CFC=? AT+CFC? AT+CFG? AT+CMUX=? AT+CMUX? AT+CQD? AT+CRC? AT+CRM=? AT+CRM? AT+CSQ=? AT+CSQ? AT+CSS=? AT+CSS? AT+CTA=? AT+CTA? AT+CXT=? AT+CXT? AT+DR? AT+DS? AT+EB? AT+EFCS? AT+ER? AT+ES? AT+ESR? AT+ETBM? AT+FBO? AT+FBU? AT+FCC=? AT+FCC? AT+FCLASS=? AT+FCQ? AT+FCR? AT+FCT? AT+FEA? AT+FFC? AT+FHS? AT+FIE? AT+FIS? AT+FLO=? AT+FLO? AT+FLP? AT+FMS? AT+FNR? AT+FNS? AT+FPA? AT+FPI? AT+FPP=? AT+FPP? AT+FPR=? AT+FPR? AT+FPS? AT+FPW? AT+FRY? AT+FSA? AT+FSP? AT+ICF=? AT+ICF? AT+IFC=? AT+IFC? AT+ILRR=? AT+ILRR? AT+IPR=? AT+IPR? AT+MA? AT+MR? AT+MS? AT+MV18R? AT+MV18S? ATE1 ATZ |
OK +CAD: (0,1) +CAD: 1 +CBC: (0,2,3),(0-100) +CBC: 0,100 OK +CDR: (0) +CDR: 0 +CDS: (0),(1),(512-65535),(6-250) +CDS: 0,1,2048,6 +CFC: (0) +CFC: 0 +CFG: "" +CMUX: (1,2) +CMUX: 2 +CQD: 10 +CRC: 0 +CRM: (0-255) +CRM: 0 +CSQ: (0-31,99),(0-7,99) +CSQ: 31,99 +CSS: (A,B,Z),(0-16383,99999) +CSS: B,4186 +CTA: (0-255) +CTA: 0 +CXT: (0,1) +CXT: 0 +DR: 0 +DS: 3,0,2048,6 +EB: 1,0,30 +EFCS: 1 +ER: 0 +ES: 3,0,2 +ESR: 1 +ETBM: 1,1,20 0 0 (0-1),(0-5),(0-4),(0-2),(0-3),(0-1),(0-1),(0-7) 0,1,0,0,0,0,0,0 0,2.0 1,0 0 1E 0 0,0,0,0 0 0 0,1,0,0,0,0,0,0 (0-2) 2 0 0 0,0,0,0 "" "" "" (0,1) 0 (8) 8 1 "" 0 "" 0 +ICF: (3),(3) +ICF: 3,3 +IFC: (0-3),(0-2) +IFC: 2,2 +ILRR: (0) +ILRR: 0 +IPR: (0,1200,2400,4800,9600,19200),(38400,57600,115200) +IPR: 19200 +MA: +MR: 0 +MS: +MV18R: 0 +MV18S: 0,0,0 OK OK |
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