Summary report of the July 1999 meeting of
IEEE 802.11
Our July 1999 meeting was held at the Queen Elizabeth Hotel, Montreal,
Province of Quebec, Canada. In addition to using the Wireless Network in
the 802.11 group, we provided a test-site to the Executive Committee members.
In fact also people in 802.15 and 802.3 were using the network.
A small group in the Executive Committee has been established to find
the best way to go forward and how to purchase equipment.
Meeting schedule
A Teleconference has been scheduled to review comments received on the
2nd Sponsor Recirculation Ballots on 11a
and 11b. The date is August 2, 1999, 10-12 AM EDT. Participants will be
invited through the 802.11 reflector to register for a conference port.
This meeting will be canceled on short notice if it turns out that there
is no business to discuss.
An interim meeting has been scheduled
Work in the 5 GHz band
"Task Group a" working on the high data-rate PHY in the 5 GHz band, project
802.11a, processed comments from it's First Sponsor Recirculation Ballot.
There is only 1 "no" votes remaining (98% support!). The editor already
implemented the resolved comments into draft D6.2, and the IEEE started
the second Sponsor Recirculation Ballot. The outcome of this ballot will
be reviewed at a teleconference, scheduled for August 2, 1999, if needed.
The Sponsor Executive Committee has given conditional approval to submit
the draft to the September meeting of the IEEE Standards Board.
The group prepared a liaison statement to ETSI BRAN and MMAC, Ethernet
Working Group, to report the last changes made and to provide feed back
on their comments. The differences between 802.11 and ETSI-BRAN are only
related to the differing requirements imposed by the respective Access
Protocols. The MMAC, Ethernet Working Group adopted the 802.11 MAC and
the 802.11a PHY.
The draft 802.11a standard is based on Orthogonal Frequency Division
Multiplexing (OFDM) to modulate the data. The main benefit OFDM modulation
is its robustness to multipath echoes, which are typical to the indoor
and mobile environments. Each OFDM symbol is composed of 52 subcarriers,
of which 48 carry data and 4 subcarriers serve as phase reference pilots.
The specifications of the Physical Layer encompass data rates from 6 Mbit/s
up to 54 Mbit/s, with 20 MHz spacing between adjacent channels. All implementations
are required to support 6, 12 and 24 Mbit/s. Optional extensions are for
9, 18, 36, 48 and 54 Mbit/s. The range of data rates is provided to match
the wide range of radio channel characteristics in both indoor and outdoor
environments. The multirate mechanism of the MAC protocol ensures that
all devices communicate with each other at the best data rate in the present
channel.
Work in the 2.45 GHz band
"Task Group b" working on the extension of the 1 and 2 Mbit/s data rates
in the 2.45 GHz band with 5.5 and 11 Mbit/s, project 802.11b, processed
comments from it's First Sponsor Recirculation Ballot. There are 6 "no"
votes remaining (still good for 92 % support!). The editor already implemented
the resolved comments into draft D6.1, and the IEEE started the second
Sponsor Recirculation Ballot. The outcome of this ballot will be reviewed
at a teleconference, scheduled for August 2, 1999, if needed. The Sponsor
Executive Committee has given conditional approval to submit the draft
to the September meeting of the IEEE Standards Board.
The modulation used is Complementary Code Keying (CCK). CCK is the mandatory
mode of operation for the (draft) standard, it is derived from the Direct
Sequence Spread Spectrum (DSSS) technology. The multirate mechanism of
the Medium Access Control (MAC) warrants that the 11 Mbit/s operation can
switch back to 5.5 Mbit/s if the radio channel is below the required value
because of the distance between the stations or because of interference.
Stations that are even further away could switch back to the 2 and 1 Mbit/s
capablities of the DSSS modulation.
Work on update of Regulatory domains
The PAR for 802.11d, the subject
of Task Group was approved, so the group could start the work now.
It reviewed two documents for
hop-sequences in various domains. For the next meeting, the group is requesting
contributions on Algorithmic determination of hop sequences, International
Mobility and Direct Sequence requirements.
New
work on Enhancements of 802.11
The group decided to start a study
group under the chairmanship of John Fakatselis to prepare a possible PAR
and 5 Criteria document for enhancements to the 802.11 standard. Elements
could include such functions as improvement of isochronous services, improved
privacy by longer keys and better authentication mechanisms, etc.
The group is looking for people
interested to do the work and calls for submissions on the topics of additional
markets served by better isochronous services, ischronous services on 802.11
using the PCF, new functionality required to support isochronous services,
stronger privacy requirements, and needs for stronger authentication.
Regulatory activities
The group prepared two documents:
-
Comments opposing the Wide Band Frequency Hopping proposal in response
to the FCC Notice of Proposed Rule Making, ET Docket No. 99-231, Proposal
to change the rules of Spread Spectrum.
-
Comments to precise IEEE 802's position in the proceeding of FFF's ET Docket
No. 98-42: 1998 Biennial Regulatory Review, Amendment of Part 18 of the
Commission’s Rules to Update Regulations for RF
Lighting Devices.
Both documents have received approval from the WG, The Sponsor Executive
Committee of IEEE 802 and the IEEE USA Activities Board.