The Future: Good News and Bad News
What innovations can we look forward to, and what problems might we
face?
A.11.1 Good News: New Standards to Help
Standards that allow coexistence between current and upcoming
protocols are in development.
A.11.1.1 802.11h
This IEEE group (802.11h) is developing
transmission power control (TPC) and
dynamic frequency selection (DFS)
protocols. These protocols will use the band more efficiently and be
required for European deployment.
The standard is expected to be available soon. Atheros
Communications, Inc. is already starting to ship 802.11a chipsets
with these features.
A.11.1.2 802.15: WPAN (Bluetooth)
The 802.15 IEEE task group is developing a set of
"Coexistence Mechanisms" that will
facilitate the coexistence of WLAN and
WPAN
devices with methods such as "Data Rate
Scaling."
A.11.1.3 802.16.2
The subgroup of "Working Group on Broadband Wireless
Access Standards" for
Metropolitan Area Networks (MANs) is
called "Coexistence of Fixed Broadband Wireless
Access Systems." This group is researching what it
takes to deploy a MAN and to solve interference issues.
A.11.2 The Bad News
New sources of interference and organized opposition to wireless
community networks may make deployment more difficult.
A.11.2.1 Radio frequency (RF) lighting
Some companies have experimented with excited sodium lamps that use
RF energy from 2.4 to 2.4835GHz. Such lamps have a broader and more
contiguous spectrum than mercury vapor. They are also four times more
efficient.
ISM band users are concerned that this type of lamp could add
considerable noise to the 2.4GHz band. Short- and long-range 802.11b
could be crippled.
A.11.2.2 Will other folks try to shut down 802.11,or will they accept it?
The ARRL is very active in commenting on proposed rules that would
give more spectrum to unlicensed users. They are particularly
concerned about spectrum that is currently used by amateurs. Some
insight can be gained at the ARRL's page on Part 15
devices at http://www.arrl.org/tis/info/part15.html.
The NTIA/IRAC is
concerned about this spectrum, because they also use it. However, the
exact use may be secret; it isn't really defined
anymore than "radionavigation"
(read: RADAR). They are also very concerned about future Ultra Wide
Band developments and have sent out a number of
"hand slaps" to the FCC for their
recent rulemaking on UWB. It is likely that they see the ISM and
U-NII bands for what they are and have given up on it and moved any
low EIRP communications from it.
Some people are also concerned that 3G license holders may be
actively working against 802.11 use, which can be seen as very cheap
competition to the very expensive 3G spectrum development and
deployment. We haven't seen anything definitive, but
keep an eye on this possible conflict.
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