IEEE P802.15 Working Group for Wireless Personal Area Networks

1
Project IEEE 802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
TG4b MAC backward compatibility Date
Submitted 14Sep2004 Source Phil Beecher
Company CompXs Ltd Address Robert Denholm
House, Bletchingley Road, Nutfield, RH1 4HW,
UK Voice44 1737 822509, E-Mail
pbeecher_at_compxs.com Re 15-04-521-nn-4b Abstr
act Requirements for backward
compatibility Purpose To focus resolutions for
802.15.4 MAC Issues. Notice This document has
been prepared to assist the IEEE 802.15. It is
offered as a basis for discussion and is not
binding on the contributing individual(s) or
organization(s). The material in this document is
subject to change in form and content after
further study. The contributor(s) reserve(s) the
right to add, amend or withdraw material
contained herein. Release The contributor
acknowledges and accepts that this contribution
becomes the property of IEEE and may be made
publicly available by 802.15.
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MAC Backward Compatibility

• Compatibility requirements
• Over air compatibility
• MAC layer primitive compatibility

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Over air compatibility

• Requirements
• At a minimum, a 802.15.4b network must coexist
  with a 802.15.4-2003 network
• This must include the following
• .4 devices must either correctly interpret or
  ignore frames from .4b network and vice versa.
• This implies frames over air must be "compatible
• Current header field assignments must be the
  same.
• New uses of previously unused fields must not
  break .4 definitions/restrictions.
• Changes to Frame header fields must not break
  .4 definitions/restrictions
• MAC commands must retain the same values.
• The order of MAC command parameter fields must
  stay the same.

4
MAC Layer Primitive Compatibility

• Requirement
• to minimise change to existing NHL designs and
  implementations.
• Implication
• The functionality of primitives must either
  remain the same or be enhanced it cannot be
  changed in a way which will necessitate
  structural design change in the NHL.
• Therefore we cannot remove parameters that will
  adversely affect the flow of the next higher
  layer.
• Cannot remove or reduce functionality of MAC
  primitives - any new parameter in .4b primitive
  must have a default value which retains the
  behaviour of .4 primitive.