IEEE 802.15 <MAC-Management_Slots>

1
Project IEEE P802.15 Working Group for Wireless
Personal Area Networks (WPANs) Submission Title
IEEE802.15.3 Management Slots in the 802.15.3
MAC. Date Submitted 19 September,
2001 Source Dr. William Shvodian Company
XtremeSpectrum Address 8133 Leesburg Pike, Suite
700, Vienna, Virginia 22182 Voice
1.703.269-3047, FAX [phone], E-Mail
bshvodian_at_xtremespectrum.com Re Abstract
This proposal describes the use of Management
Slots for the 802.15.3 MAC. Purpose To
provide an improvement to the current version of
the 802.15.3 MAC Notice This document has been
prepared to assist the IEEE P802.15. 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 P802.15.
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Overview

• 802.15.3 currently has no restrictions on traffic
  in the CAP Data, Commands (Association and
  other), EPS
• The impact the amount of traffic in the CAP has
  not been assessed in terms of the size of the
  CAP, the overhead it will cause and the
  probability of collision.

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Overview

• Getting Management traffic (commands) out of the
  CAP can reduce the size of the CAP
• This proposal shows a straightforward way to
  reduce the amount of traffic in the CAP by
  putting command frames into Management GTS slots

4
New Information Element in the Beacon

• CAP Control Mode Information Element
• Data in the CAP (allowed/not allowed)
• EPS in CAP (allowed/not allowed)
• Commands in the CAP (allowed/not allowed) Note
  Does not included Association
• Association in the CAP (allowed/not allowed). If
  Association is not allowed in the CAP,
  Association shall be sent in an MTS with the PNC
  as the destination and the unassigned address as
  the source. Slotted Aloha will be the access
  mechanism in this slot.

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CAP Control Mode Information Element
1 octet
1 octet
1 bit
1 bit
1 bit
12 bits
1 bit
Assoc. In CAP
Element ID
Length
Data in CAP
EPS In CAP
Reserved
Commands In CAP

• CAP Control Mode Information Element sent in
  Beacon if Data, Commands or EPS frames are not
  allowed in the CAP.
• Default is that Data, Commands, Association and
  EPS are allowed in CAP
• PNC can minimize the needed CAP size by
  disallowing Data and Commands in the CAP
• Also, Disallowing Data and commands in the CAP
  allows stations to not listen to the CAP

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Commands in Management Slots

• If Commands are not allowed in CAP, they are sent
  in Management Slots
• The PNC allocates one or more GTS slots as
  Management Slots. Management slots are simply
  GTS slots, where the PNC address (zero) is either
  the SA or the DA.
• The PNC can change the assigned station for
  management slots in any beacon.

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Management Slot Options
Contention Access Period
Contention Free Period
Beacon
1
2
4
5
3

• A single management slot can be used where the SA
  can be assigned to different DEVs, including PNC,
  each superframe. The DA will be the PNC DA
  except when PNC address is the SA

Contention Access Period
Contention Free Period
Beacon
1
2
4
5
3
6

• Slot 1 can be assigned to DEV SAs with PNC DA for
  DEV to PNC commands, with Slot 2 assigned to PNC
  SA with DEV DAs for PNC to DEV commands

Contention Access Period
Contention Free Period
Beacon
1
2
3
4
5
7
8
6
9

• PNC may allocate multiple management GTS slots
  for commands

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Summary

• New CAP Control Mode Information Element in the
  Beacon to control the type of frames allowed in
  the CAP.
• If the PNC disallows command frames in the CAP,
  management GTS slots are used to transmit command
  frames