IEEE 802.15 WPAN Low Rate Alternative PHY Task Group 4a (TG4a)



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The IEEE 802.15 Low Rate Alternative PHY Task Group (TG4a) for Wireless Personal Area Networks (WPANs) has defined a project for an amendment to 802.15.4 for an alternative PHY.

The principle interest is in providing communications and high precision ranging / location capability (1 meter accuracy and better), high aggregate throughput, and ultra low power; as well as adding scalability to data rates, longer range, and lower power consumption and cost. These additional capabilities over the existing 802.15.4 standard are expected to enable significant new applications and market opportunities.


In March 2004, 802.15.4a became an official Task Group; with its committee work tracing back to November 2002. The committee has completed its efforts to draft an alternate PHY specification for the applications identified in accordance with the project timeline adopted at start of the task group.

In March 2005, TG4a selected a baseline specification without enacting our down-selection procedures, and as a result, confirmed the baseline with 100% approval. The baseline consisted of two optional Phys consisting of a UWB Impulse Radio (operating in unlicensed UWB spectrum) and a Chirp Spread Spectrum (operating in unlicensed 2.4GHz spectrum).

On  December 2005 TG4a sent the draft standard to Working Group letter ballot with the final recirculation ending on 24 August 2006 with a cumulative vote of 158 affirmative votes, 19 negative votes, and 19 abstentions; the ballot carried allowing the draft to be sent to Sponsor Ballot.

On the 31 August, P802.15.4a went out to Sponsor Ballot with the final recirculation closing on 27 January 2007.  Since the cumulative vote on P802.15.4a was 96 affirmative votes, 2 negative votes, and 13 abstentions the ballot carried and P802.15.4a was allowed to proceed to RevCom for review.

On the 22 March 2007; P802.15.4a was approved as a new amendment to IEEE Std 802.15.4-2006 by the IEEE-SA Standards Board.

Current Status

P802.15.4a is complete and requires no further TG4a effort.  The editor staff of TG4a will work with the IEEE-SA standards group to publish this standard with the target date of end of June 2007

How to participate

There are no further scheduled meetings or conference calls for this activity.

The final draft standard document is available on the member only section of this website.

Who to contact with questions


The Institute of Electrical and Electronics Engineers, Inc.





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(Modified: 30-Mar-2007), Rev. 0.5 by Rick Alfvin