7.1 Cellular Networking Price and Performance
Cellular networking offers the following downstream speeds (for activities such as receiving email, downloading files via FTP, and surfing the Web):
19.2 Kbps on first generation (1G) networks. Cellular Digital Packet Data (CDPD) is a once-popular 1G service that cellular providers are hoping to phase out.
30-70 Kbps on early third-generation (3G) networks (often referred to as 2.5G), sometimes peaking to 144 Kbps. General Packet Radio Services (GPRS) is the leading 2.5G service. AT&T Wireless uses GPRS for its mMode consumer-oriented data plans and its Mobile Internet business-oriented data plans. T-Mobile uses GPRS for its T-Mobile Internet data plans. Cingular also uses GPRS on their GSM network.
144 Kbps and higher on 3G networks. CDMA2000, Enhanced Data GSM Environment (EDGE), and UMTS are emerging 3G technologies. The first phase of CDMA2000 is 1x Radio Transmission Technology (1xRTT), which is used by Verizon's Express Network and Sprint's PCS Vision. At the time of this writing, EDGE is not widely available, but has reportedly been quietly deployed by AT&T Wireless and Cingular.
Upstream speeds (for activities such as sending email, using FTP to upload files, and uploading documents to web sites) are generally less than the downstream speeds, anywhere from 9.6 Kbps to about half the downstream speed.
One of the fundamental limits on cellular networking is the price of data. Typical packages offer a bucket of data with coverage charged per kilobyte over the limit. Table 7-1 shows some examples based on current U.S. pricing.
|
Data quantity |
1G |
2.5G and 3G |
|---|---|---|
|
Unlimited |
$40-$60/month |
$80 or more per month for 1xRTT or GPRS service. At the time of this writing, T-Mobile is the only GPRS provider offering cheap unlimited data plans ($20.00/month). |
|
5 MB |
n/a |
$15-$20 per month |
|
20 MB |
n/a |
$35-$55 per month |
A busy user can easily blow through 20 MB in just a couple of hours of web surfing and email. Heavy users should opt for an unlimited pricing plan, or carefully plan out their usage to take advantage of (free, if possible) Wi-Fi hotspots and use the cellular service only when absolutely necessary (such as sending out an urgent email while sitting on a runway).
Even with a data allotment that you're comfortable with, service can be spotty, though coverage is most comprehensive in densely populated areas (especially Europe and Asia). However, in a densely populated area such as New York City, buildings can interfere with the signals, and many simultaneous users can limit the performance of the network in a given area.
As tempting as it is to chalk up performance problems to early adoption doldrums, the old maxim still stands: let the buyer beware. If you knowingly purchase poor service in the hopes that it will improve over time, keep in mind that there is no guarantee that it will. When in doubt, seek the opinions of others. Howard Forums (http://www.howardforums.com) is an excellent resource. Also, the Usenet hierarchy alt.cellular has many newsgroups devoted to specific carriers where you can read about peoples' experiences (you can read and post to these newsgroups through Google Groups at http://groups.google.com/). Be sure to get service from a provider who offers a complete refund, no questions asked, within a reasonable trial time (some providers offer 15 days, which is too little, so try pressuring the salesperson for a 30-day trial).
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