Wireless Local Area Networks (WLAN) fall into two primary categories: public and
private. In 2003, public wireless LAN locations, known as "hotspots," numbered
approximately 30,000, but research suggests the number will more than quadruple
by 2006. Private wireless LANs are also becoming increasingly common in corporate
environments to meet the changing definition of a mobile employee: from someone
out in the field to someone who moves around the corporate complex and needs
to retain network access as he or she roams from place to place. The technology
is being driven by four major standards.
- Bluetooth. Bluetooth wireless technology provides links between mobile
computers, mobile phones, and portable handheld devices, as well as connectivity
to the Internet. Bluetooth operates at 2.4 GHz, and has a range of about 10 meters.
- IEEE 802.11b "WiFi." WiFi runs in the 2.4 GHz range, and has a
maximum speed of 11 megabits per second. 802.11b has a range of about 100 meters
indoors and 300 meters outside. It is prone to interference from 2.4 GHz cordless
phones and microwave ovens.
- IEEE 802.11a. 802.11a runs in the 5 GHz range, and has a
maximum speed of about 54 megabits per second. 802.11a is not prone to interference like
WiFi because it is in a largely unused frequency range. However, 802.11a has a
shorter range and requires more access points to cover the same area. It is also
not backwards compatible with WiFi.
- IEEE 802.11g. 802.11g supports a higher transmission speed of
54 megabits per second, is completely backwards compatible with WiFi, and benefits
from the longer range of WiFi. However, 802.11g operates in the 2.4 GHz band, so
it does have the same interference problems as WiFi.
WiFi and the other IEEE 802.11 standards were developed as local area networking technologies.
They were never designed to cover wide areas and support true mobility by allowing roaming
from one access point to another without service interruption. For the most part, developments
in the field of wide area data networking remain the domain of the telecommunications
industry, and these players view public WLAN implementations like WiFi hotspots as an
encroachment on their territory. The industry argues that you wouldn't need hotspots if
wireless data access was as comprehensive as cellular voice. Vendors are pushing WiFi in
the short-term to drive market demand, but expect to eliminate the need for WiFi hotspots
in the future.
The telecommunications industry is focused on developing third generation wireless systems
(known as 3G) to deliver high-speed, wide-are coverage. Three important technologies will play
an important role in the development of 3G:
- Universal Mobile
Telecommunication System (UMTS). UMTS
extension of the existing Global System
for Mobile Communications (GSM) network that uses the Wideband Code Division Multiple
Access (WCDMA) air interface to deliver broadband quality transfer speeds over wide areas.
- Code Division Multiple
Access (CDMA) 2000. The second generation
of the CDMA standard (IS-95) is CDMA 2000. The first version provides transfer
speeds of up to 614 kilobits per second, but a new data-optimized version promises
much higher transfer speeds.
- Time Division
Synchronous Code Division Multiple Access (TD-SCDMA).
TD-SCDMA systems can be connected to existing GSM networks, which allows simple and
cost-effective internetworking between 2G and 3G network operations. Data can be
sent and received while traveling at very high speeds of up to 150 mph.
For more information on choosing the right wireless solution for your
company, please read our Wireless
Go to Bitpipe Research Guide: Wireless.