December 12, 2000, 4:09 PM —
Do your bandwidth-intensive
applications need more than the 11 Mbps supplied by the href="http://mithras.itworld.com/articles/columns/net-geier-0323.html">IEEE 802.11b-
compliant devices I wrote about in my last?
You may have a long wait before the higher data rate offerings of 802.11a are
available. Though I am and always have been a strong supporter of 802.11, I recommend
that you consider HiperLAN-based products, which
currently offer the fastest wireless LANs available worldwide, while you wait.
What's HiperLAN? It began life in Europe as a specification (EN 300 652) ratified in
1996 by the European Telecommunications Standards
Institute (ETSI) Broadband Radio Access
Network organization. HiperLAN/1, the current version, operates in the 5 GHz radio
band at speeds as high as 24 Mbps.
Like Ethernet and 802.11, HiperLAN/1 uses a carrier sense multiple access protocol
to give wireless LAN access to end-user devices. CSMA regulates traffic on the LAN by
having devices listen for other transmissions and transmit data only when no other
device is transmitting. HiperLAN/1 also provides quality-of-service (QoS) support for
the varying needs of data, video, voice, and images. Proxim's href="http://www.proxim.com/">
RangeLAN5 product family was the first HiperLAN offering available in the US, and I
haven't seen any other US-based wireless LAN manufacturers follow.
What other choices do you have for high-speed wireless LANs based on an approved
standard? None. Companies are currently developing IEEE 802.11a-compliant devices with
data rates as high as 20 Mbps, but it will probably be the end of 2000 before any are
available on the market.
ETSI is currently developing HiperLAN/2 under an organization called the
href="http://www.hiperlan2.com/">HiperLAN/2 Global Forum, or H2GF.
HiperLAN/2 will operate in the 5 GHz band at speeds as high as 54 Mbps using a
connection-oriented protocol for sharing access among end-user devices. HiperLAN/2 will
include QoS support and be capable of carrying Ethernet frames, ATM cells, and IP
packets. Don't expect to see products that make use of these capabilities until early
Not sure which wireless LAN standard fits your needs today? Consider the following
when deciding whether to use HiperLAN or IEEE 802.11 products:
Analyze your need for network bandwidth. Do you really need the
higher speed of HiperLAN, or can you get by with the 11 Mbps provided by 802.11b? The
higher the utilization, the more bandwidth you'll need. If you need to transmit video
or large images, you should also lean towards toward HiperLAN.