Many digital phones are advertised as Internet-ready, coming
with a browser or a connectivity kit. Advertising for Wireless
Internet modems or Internet-ready phones can be very deceiving,
however. If the ad mentions a data rate of 19.2 Kbps, then
it’s CDPD. The phone may be CDMA or TDMA but the data
connection is through either an internal or external CDPD
modem connected to an analog channel. If a TDMA or CDMA
phone has a data connectivity kit, such as a cable to connect
the phone and a laptop, and it does not mention the data rate,
or if the phone has an internal browser, the modem is integrated
into the phone and probably uses the rate of the traffic
channel, 8 Kbps for TDMA and 9.6 or 14.4 Kbps for CDMA.
GSM phones have long used data capabilities built into the
phones so that they connect to a laptop by cable or include
built-in modems to send data in the traffic channel at 9.6
Kbps. In all of these cases except CDPD, the connection is still
circuit-switched for 2G networks.
A second type of modem is essentially a phone without
voice capabilities on a PCMCIA card. There are modems of
this type for every technology. They have an antenna integrated
into them or are connected by a short cable to an antenna.
Again, if the data rate is specified as 19.2 Kbps, it’s CDPD. If
the rate is not specified, it’s probably using a traffic channel.
Some PCMCIA modems offer a data rate of 56 Kbps and mention
wireless in the same sentence. These actually combine two
modems in one: a 56K landline modem and a wireless traffic
channel modem.
With the launch of 2.5G and 3G networks, modems will
become available having much higher data rates. They will fall
into the same two categories: internal to a phone with a cable
connection to a laptop or as a PCMCIA card. GPRS technology
is just being launched in Europe but as with all new technologies,
GPRS modems are still scarce. The United States will see next
generation modems for CDMA and TDMA phones by 2002. The
CDMA phones will use 1xRTT technology, and the TDMA
phones will use GPRS. The CDMA standard 1xEV, with data
rates up to 2.4 Mbps, will not be available until later. Products for
W-CDMA will become available later in 2002 or 2003. 65