IEEE C802.16n-11/0182r1
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Self-coexistence Cycle for 802.16n Advanced Network
Date
Submitted
2011-09-12
Source(s)
Ming-Tuo Zhou1, Xin Zhang1, Liru Lu1,
Hoang Vinh Dien1, Masayuki Oodo2,
Hiroshi Harada1,2
Voice: +65 6771 1007
E-mail: mingtuo@nict.com.sg
National Institute of Information and
Communications Technology
1
: 20 Science Park Road, #01-09A/10
TeleTech Park, Singapore 117674
2
: 3-4, Hikarino-oka, Yokosuka,
Kanagawa, Japan, 239-0847
Re:
Call for Comments for 802.16n AWD
Abstract
802.16n amendment draft
Purpose
To propose AWD text about self-coexistence cycle for 802.16n Advanced network
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IEEE C802.16n-11/0182r1
Self-coexistence Cycle for 802.16n Advanced Network
Ming-Tuo Zhou, Xin Zhang, Liru Lu,
Hoang Vinh Dien, Masayuki Oodo, Hiroshi Harada
National Institute of Information and Communications Technology
Introduction
Self-coexistence is required in 802.16n network due to mobile HR-BS/RS/MS and
relatively long interference distance at VHF frequencies. It can be achieved by sharing
the same channel in time. Particularly, each cell in self-coexistence operates on one or
several frames of a self-coexistence cycle exclusively.
Self-coexistence cycle is a periodical structure repeated along time for channel sharing in
self-coexistence mechanism. A self-coexistence cycle may consist of a number of frames
or superframes (depending on the standard that 802.16n is made amendment to). The
structure of a self-coexistence needs to meet following requirements:

an HR networks in self-coexistence is able to share a minimum number of frames
for data packets transmission

the HR networks in self-coexistence all have transmission opportunities for PA/SA-preambles and superframe headers (SFHs)

the duration of self-coexistence is easy for inter-HR-BS synchronization

the self-coexistence cycle is backward compatible
Based on 802.16m frame/superframe structure and in consideration of the above
requirements, a self-coexistence cycle structure for HR Advanced network is proposed in
this document. It consists of twelve superframes. Structure of superframe is defined in
802.16m, i.e., each superframe consists of 4 frames and duration of each frame is 5 ms.
In normal mode of data service, an HR network transmits PA-/SA-preambles and SFH
normally as that defined in 802.16m, i.e., in each of the twelve superframes of a selfcoexistence cycle, it transmits an SA-preamble, an PA-preamble, and one more SApreamble in the first symbol of the first, the second, and the third frame, respectively.
When self-coexistence mechanism is used in 802.16n network, it may lead to an HRMS/RS loss synchronization to its serving HR-BS if no appropriate method is adopted.
This is because that in the last subframe (self-coexistence zone) of the third frame of a
IEEE C802.16n-11/0182r1
superframe, an HR-MS/RS may receive an A-preamble from a neighbor HR network and
then synchronize to the neighbor, while loss synchronization to its serving HR-BS.
In order to recover synchronization to the serving HR-BS when above case happens, it
proposes that even in normal operation mode, in the first of symbol of the fourth frame of
a superframe, an HR network transmits an SA-preamble.
An example is shown in Fig. 1. In this example, cell_1 operates in normal mode and it
occupies all frames. It transmits an SA-preamble in the first symbol of the first frame of
each superframe, a PA-preamble in the first symbol of the second frame of each
superframe, an SA-preamble in the first symbol of the third frame of each superframe, an
additional SA-preamble in the first symbol of the fourth frame of each superframe, and
SFH in the first subframe of the first frame of each superframe of a self-coexistence
cycle.
Self-coexistence cycle (240ms, 12 superframes)
…...
F0
cell_1
F1
cell_1
SF0
F2
cell_1
SF1
F3
cell_1
SF2
…...
SF3
F0
F1
F2
cell_1
cell_1
cell_1
F3
cell_1
F0
F1
F2
F3
F0
F1
F2
cell_1
cell_1
cell_1
cell_1
cell_1
cell_1
cell_1
SA-preamble
…...
SF11
PA-preamble
F3
cell_1
…...
F0
F1
F2
cell_1
cell_1
cell_1
SFH
Fig. 1 Example of self-coexistence cycle structure for 802.16n cell with WirelessMAN
HR-Advanced air interface operating in normal mode.
In self-coexistence mode of data service, each HR network occupies one or more frames
of a superframe exclusively. However, an HR network needs to transmit PA-/SApreamble and SFH in a superframe as that described in 802.16m, for purpose of backward
compatibility. Otherwise, an AMS is unable to operate under control of an HR-BS.
To meet the requirement of backward compatibility, an HR network needs to transmit a
set of A-preambles and SFH as that described in 802.16m. In another hand, each HR
network occupies one or more frames of superframe exclusively. This leads to a mixed
design of self-coexistence cycle in self-coexistence mode of data service, i.e., inside a
F3
cell_1
IEEE C802.16n-11/0182r1
superframe, each HR network occupies one or more frames exclusively except the
symbols for transmission of A-preambles and SFH, while the HR networks transmit a set
of A-preambles and SFH in turn in superframes of a self-coexistence cycle.
Figure 2 shows an example of structure of self-coexistence cycle where three cells
(cell_1, cell_2, and cell_3) share the same frequency channel by mechanism of selfcoexistence. Cell_1 occupies the first frame (F0) of all superframes of a self-coexistence
cycle. Cell_2 occupies the second frame (F1) of all superframes of a self-coexistence
cycle. Cell_3 occupies the third and the fourth frame (F2 and F3) of all superframes of a
self-coexistence cycle. Cell_1 transmits an SA-preamble in the first symbol of the first
frame (F0), a PA-preamble in the first symbol of the second frame (F1), an SA-preamble
in the first symbol of the third frame (F2), and SFH in the first subframe of the first
frame, of superframe SF0, SF3, SF6, and SF9. Similarly, cell_2 transmits a set of SApreamble, PA-preamble and SFH in SF1, SF4, SF7, and SF10. Similarly, cell_3 transmits
a set of SA-preamble, PA-preamble and SFH in SF2, SF5, SF8, and SF11.
Self-coexistence cycle (240ms, 12 superframes)
…...
SF0
SF1
SF2
SA-preamble
(cell_3, cell_1)
F0
F1
F2
cell_1
cell_2
cell_3
cell_3
SA-preamble
(cell_3)
SFH
(cell_1)
PA-preamble
(cell_1, cell_2)
SA-preamble
(cell_1)
F3
F0
SA-preamble
(cell_1, cell_3)
cell_1
SFH
(cell_3)
cell_2
SFH
(cell_2) PA-preamble
(cell_2)
SA-preamble
(cell_2, cell_1)
…...
SF11
PA-preamble SA-preamble
(cell_3, cell_2)
(cell_3)
F0
F1
…...
SF3
cell_1
F2
F1
F2
F3
cell_2
cell_3
cell_3
F3
cell_3
cell_3
SA-preamble
(cell_3)
F0
F1
F2
cell_1
cell_2
cell_3
SA-preamble
SA-preamble
(cell_1)
PA-preamble
cell_3
SA-preamble
(cell_3)
SFH
(cell_1)
PA-preamble
(cell_1, cell_2)
SA-preamble
(cell_2, cell_3)
F3
SA-preamble
(cell_1, cell_3)
…...
F0
F1
F2
cell_1
cell_2
cell_3
SFH
(cell_3)
PA-preamble
(cell_3, cell_2)
SA-preamble
(cell_3, cell_1)
F3
cell_3
SA-preamble
(cell_3)
SA-preamble
(cell_3)
SFH
Fig. 2 Example of self-coexistence cycle structure for 802.16n cells with WirelessMAN
HR-Advanced air interface operating in self-coexistence mode: cell_1, cell_2, and cell_3
share the same frequency channel.
In above example, an 802.16m station in any of the three HR cells is able to receive Apreambles and SFH.
In above mixed design of self-coexistence cycle in self-coexistence mode, an HR
network still needs to transmit addition preambles for synchronization among its HR
stations. This is because that in a frame that an HR network does not occupy, the
subordinate HR stations may loss synchronization to the serving HR-BS since in the first
IEEE C802.16n-11/0182r1
symbol of that frame, another HR network may transmit A-preambles normally. A
solution to this issue is that the HR network transmits additional A-preamble in the first
symbol of this frame. If this frame is the first, third or the fourth frame of a superframe,
then the HR network transmits additional SA-preamble. If the frame is the second frame
of a superframe, then the HR network transmits additional PA-preamble.
In above, if two HR networks in self-coexistence are from the same cell ID segment, then
it may introduce interference each other when one of them transmits additional SApreamble in a symbol that another transmits SA-preamble normally. To solve this issue,
the HR network transmitting additional SA-preamble transmits additional substitute SApreamble, instead of transmitting its SA-preamble. A substitute SA-preamble is a SApreamble corresponds to a substitute cell ID, which is an cell ID in a segment different
from the one of the HR network. The method to choose a substitute cell ID is as
following:
If the original segment is n, then the cell chooses segment of the substitute cell ID
segment as j=MOD((n+1), 3). MOD represents operation of modulo. And it
chooses the substitute cell ID as cell_ID_sub = j*256 + MOD(cell_ID_org, 256),
cell_ID_org is the original cell ID.
The subordinate HR stations will be informed the selected substitute cell ID.
Proposed Text for the 802.16n Amendment Working Document (AWD)
Note:
The text in BLACK color: the existing text in the 802.16n Amendment Draft Standard
The text in RED color: the removal of existing 802.16n Amendment Draft Standard Text
The text in BLUE color: the new text added to the 802.16n Amendment Draft Standard
Text
[------------------------------------------Start of Text Proposal------------------------------------]
17.3.11.1 Self-coexistence cycle
TBD
IEEE C802.16n-11/0182r1
A self-coexistence cycle of consists of twelve superframes. Structure of superframe is
described in WirelessMAN Advanced, i.e., each superframe consists of 4 frames and
duration of each frame is 5 ms.
17.3.11.1.1 Self-coexistence cycle structure in normal mode
When an HR cell operates in normal mode, it occupies all frames of a superframe,
and transmits SA-preamble, PA-preamble, and SFH (superframe header) in every
superframe of a self-coexistence cycle as that described in WirelessMAN Advanced.
In addition to transmitting SA-preambles and PA-preamble as described in
WirelessMAN Advanced, an HR cell transmits an SA-preamble in the first symbol
of the fourth frame of each superframe.
An example is shown in Fig. xx01. Cell_1 operates in normal mode and it occupies
all frames. It transmits an SA-preamble in the first symbol of the first frame of each
superframe, a PA-preamble in the first symbol of the second frame of each
superframe, an SA-preamble in the first symbol of the third frame of each
superframe, an additional SA-preamble in the first symbol of the fourth frame of
each superframe, and SFH in the first subframe of the first frame of each
superframe of a self-coexistence cycle.
Self-coexistence cycle (240ms, 12 superframes)
…...
F0
cell_1
F1
cell_1
SF0
F2
cell_1
SF1
F3
cell_1
SF2
…...
SF3
F0
F1
F2
cell_1
cell_1
cell_1
F3
cell_1
F0
F1
F2
F3
F0
F1
F2
cell_1
cell_1
cell_1
cell_1
cell_1
cell_1
cell_1
SA-preamble
…...
SF11
PA-preamble
F3
cell_1
…...
F0
F1
F2
cell_1
cell_1
cell_1
SFH
Figure xx01 Example of self-coexistence cycle structure for HR cell operating in
normal mode.
17.3.11.1.2 Self-coexistence structure in self-coexistence mode
F3
cell_1
IEEE C802.16n-11/0182r1
In self-coexistence mode, each HR cell occupies one or several frames of a
superframe exclusively and the cells transmit SA-preambles, PA-preamble, and SFH
normally as described in WirelessMAN Advanced in turn. In the first symbol of a
frame that an HR cell occupies, it transmits an additional A-preamble if it does not
normally transit an A-preamble in that symbol. If in that symbol, a neighbor HR
cell transmits an SA-preamble normally, in order to avoid interference, the HR cell
transmits a substitute SA-preamble if the two HR cells are in the same cell ID
segment.
17.3.11.1.2.1 Transmitting A-preambles and SFH normally
To normally transmit a set of SA-preamble, PA-preamble and SFH means that an
HR cell transmits an SA-preamble in the first symbol of the first frame of a
superframe, a PA-preamble in the first symbol of the second frame of a superframe,
an SA-preamble in the first symbol of the third frame of a superframe, and SFH in
the first subframe of the first frame of a superframe, as that described in
WirelessMAN Advanced.
HR cells in self-coexistence transmit normally a set of SA-preamble, PA-preamble
and SFH in the twelve superframes of a self-coexistence cycle in turn. In case that
there are two HR cells in self-coexistence, one HR cell transmits normally a set of
SA-preamble, PA-preamble and SFH in SF0, SF2, SF4, SF6, SF8 and SF10,
respectively, and the other HR cell transmits normally a set of SA-preamble, PApreamble and SFH in SF1, SF3, SF5, SF7, SF9 and SF11, respectively. In case that
there are three HR cells in self-coexistence, the first cell transmits normally a set of
SA-preamble, PA-preamble and SFH in SF0, SF3, SF6 and SF9, respectively, the
second HR cell transmits normally a set of SA-preamble, PA-preamble and SFH in
SF1, SF4, SF7, and SF10, respectively, and the third cell transmits normally a set of
SA-preamble, PA-preamble and SFH in SF2, SF5, SF8 and SF11, respectively. In
case that there are four HR cells in self-coexistence, the first HR cell transmits
normally a set of SA-preamble, PA-preamble and SFH in SF0, SF4 and SF8,
respectively, the second HR cell transmits normally a set of SA-preamble, PApreamble and SFH in SF1, SF5 and SF9, respectively, the third HR cell transmits
normally a set of SA-preamble, PA-preamble and SFH in SF2, SF6 and SF10,
respectively, and the fourth HR cell transmits normally a set of SA-preamble, PApreamble and SFH in SF3, SF7 and SF11, respectively.
Figure xx02 shows an example of structure of self-coexistence cycle where three HR
cells (cell_1, cell_2, and cell_3) share the same frequency channel by mechanism of
self-coexistence. Cell_1 occupies the first frame (F0) of all superframes of a selfcoexistence cycle. Cell_2 occupies the second frame (F1) of all superframes of a selfcoexistence cycle. Cell_3 occupies the third and the fourth frame (F2 and F3) of all
superframes of a self-coexistence cycle. Cell_1 transmits an SA-preamble in the first
symbol of the first frame (F0), a PA-preamble in the first symbol of the second
IEEE C802.16n-11/0182r1
frame (F1), an SA-preamble in the first symbol of the third frame (F2), and SFH in
the first subframe of the first frame, of superframe SF0, SF3, SF6, and SF9.
Similarly, cell_2 transmits normally a set of SA-preamble, PA-preamble and SFH in
SF1, SF4, SF7, and SF10. Similarly, cell_3 transmits normally a set of SA-preamble,
PA-preamble and SFH in SF2, SF5, SF8, and SF11.
Self-coexistence cycle (240ms, 12 superframes)
…...
SF0
SF1
SF2
SA-preamble
(cell_3, cell_1)
F0
F1
F2
cell_1
cell_2
cell_3
cell_3
SA-preamble
(cell_3)
SFH
(cell_1)
PA-preamble
(cell_1, cell_2)
SA-preamble
(cell_1)
F3
F0
SA-preamble
(cell_1, cell_3)
cell_1
SFH
(cell_3)
cell_2
SFH
(cell_2) PA-preamble
(cell_2)
SA-preamble
(cell_2, cell_1)
…...
SF11
PA-preamble SA-preamble
(cell_3, cell_2)
(cell_3)
F0
F1
…...
SF3
cell_1
F2
F1
F2
F3
cell_2
cell_3
cell_3
F3
cell_3
cell_3
SA-preamble
(cell_3)
F0
F1
F2
cell_1
cell_2
cell_3
SA-preamble
SA-preamble
(cell_1)
PA-preamble
cell_3
SA-preamble
(cell_3)
SFH
(cell_1)
PA-preamble
(cell_1, cell_2)
SA-preamble
(cell_2, cell_3)
F3
SA-preamble
(cell_1, cell_3)
…...
F0
F1
F2
cell_1
cell_2
cell_3
SFH
(cell_3)
PA-preamble
(cell_3, cell_2)
SA-preamble
(cell_3, cell_1)
Figure xx02 Example of self-coexistence cycle structure for HR cells operating in
self-coexistence mode: cell_1, cell_2, and cell_3 share the same frequency channel.
Figure xx03 shows one more example of structure of self-coexistence cycle where
cell_1 and cell_4 share the same frequency channel. Cell_1 occupies the first, the
second, and the third frame of all superframes of a self-coexistence cycle. Cell_2
occupies the fourth frame of all superframes of a self-coexistence cycle. Similar to
previous example, cell_1 normally transmits a set of SA-preamble, PA-preamble,
and SFH in SF0, SF2, SF4, SF6, SF8 and SF10, of a self-coexistence cycle. Cell_4
normally transmits a set of SA-preamble, PA-preamble, and SFH in SF1, SF3, SF5,
SF7, SF9, and SF11 of a self-coexistence cycle.
cell_3
SA-preamble
(cell_3)
SA-preamble
(cell_3)
SFH
F3
IEEE C802.16n-11/0182r1
Self-coexistence cycle (240ms, 12 superframes)
…...
SF0
SF1
SF2
PA-preamble
(cell_1)
SA-preamble
(cell_1)
F0
F1
F2
cell_1
cell_1
cell_1
cell_4
SA-preamble
(cell_4)
SFH
(cell_1)
PA-preamble
(cell_1)
SA-preamble
(cell_1)
F3
F0
SA-preamble
(cell_1)
cell_1
F0
SFH
(cell_1)
F1
cell_1
cell_1
F2
SA-preamble
(cell_4, cell_1)
F2
cell_1
cell_1
cell_4
SA-preamble
(cell_4)
F3
F3
F0
F1
F2
cell_1
cell_1
cell_1
cell_4
SA-preamble
(cell_4)
SFH
(cell_4)
PA-preamble
(cell_1, cell_4)
SA-preamble
(cell_4, cell_1)
SA-preamble
…...
SF11
SA-preamble
(cell_1)
F1
cell_1
cell_4
SA-preamble
(cell_4)
SFH
(cell_4) PA-preamble
(cell_1, cell_4)
…...
SF3
SA-preamble
(cell_4, cell_1)
PA-preamble
SA-preamble
(cell_4, cell_1)
F3
…...
F0
F1
F2
cell_1
cell_1
cell_1
cell_4
SA-preamble
(cell_4)
SFH
(cell_4)
PA-preamble
(cell_1, cell_4)
SA-preamble
(cell_4, cell_1)
SA-preamble
(cell_4, cell_1)
SFH
Figure xx03 Example of self-coexistence cycle structure for HR cells operating in
self-coexistence mode: cell_1 and cell_4 share the same frequency channel.
17.3.11.1.2.2 Transmitting additional A-preambles
If an HR cell occupies a frame and it does not transmit an A-preamble normally as
that described in 17.3.11.1.2.1, it transmits an additional A-preamble in the first
symbol of the frame.
In above, if the frame is the second frame (F1) of a superframe, then the cell
transmits additional PA-preamble in the first symbol of this frame.
In above, if the frame is the fourth frame (F3), then the cell transmits an additional
SA-preamble in the first symbol of the frame.
In above, if the frame is the first (F0) or the third frame (F2) of a superframe, and
the cell ID of this HR cell is in different cell ID segment as the HR cell that transmits
A-preambles normally in this superframe as that described in 17.3.11.1.2.1, then this
HR cell transmits an additional SA-preamble in the first symbol of the frame.
In above, if the frame is the first (F0) or the third frame (F2), and the cell ID of this
HR cell is in the same cell ID segment of the HR cell that normally transmits Apreamble in this superframe as described in 17.3.11.1.2.1, then this HR cell
transmits an additional substitute SA-preamble in the first symbol of the frame. An
additional substitute SA-preamble carries a substitute cell ID that is in different cell
F3
IEEE C802.16n-11/0182r1
ID segment of the HR cell that normally transmits A-preambles in this superframe.
The method that a cell chooses a substitute cell ID and determines substitute SApreamble is described in 17.3.11.1.2.3.
In example shown in Fig. xx02, cell_1 transmits additional (substitute) SA-preamble
in the first symbol of the first frame of superframe SF1, SF2, SF4, SF5, SF7, SF8,
SF10, and SF11, cell_2 transmits additional PA-preamble in the first symbol of the
second frame of superframe SF0, SF2, SF3, SF5, SF6, SF8, SF9, and SF11, cell_3
transmits additional (substitute) SA-preamble in the first symbol of the third frame
and additional SA-preamble in the first symbol of the fourth frame, of superframe
SF0, SF1, SF3, SF4, SF6, SF7, SF9, and SF10.
In example shown in Fig. xx03, cell_1 transmits additional (substitute) SA-preamble
in the first symbol of the first and the third frame of superframe SF1, SF3, SF5,
SF7, SF9, and SF11, and it transmits additional PA-preamble in the first symbol of
the second frame of the same superframe, cell_4 transmits additional SA-preamble
in the first symbol of the fourth frame of superframe SF0, SF2, SF4, SF6, SF8, and
SF10.
17.3.11.1.2.3 Choosing substitute cell ID and determining substitute SA-preamble
The method to choose a substitute cell ID is as following:
If the original segment is n, then the cell chooses segment of the substitute cell ID
segment as j=MOD((n+1), 3). MOD represents operation of modulo. And it chooses
the substitute cell ID as cell_ID_sub = j*256 + MOD(cell_ID_org, 256), cell_ID_org
is the original cell ID.
The substitute SA-preamble is corresponding to the substitute cell ID: the carrier set
of the SA-preamble is the segment ID j. When the cell transmits a substitute SApreamble, it uses the carrier set j.
The selected substitute cell ID cell_ID_sub and its segment ID j are distributed to all
of its subordinate stations.