IEEE C802.16p-11/0068
Project
IEEE 802.16 Broadband Wireless Access Working Group <http://ieee802.org/16>
Title
Time-Sharing STID Addressing Scheme
Date
Submitted
2011-05-08
Source(s)
Ming-Hung Tao, Ying-Chuan Hsiao
E-mail: mhtao@itri.org.tw
ITRI
*<http://standards.ieee.org/faqs/affiliationFAQ.html>
Re:
[STDS-802-16] 802.16p (M2M) AWD Call for Comments
Abstract
This contribution proposes a new STID addressing scheme for M2M devices.
Purpose
To be discussed and agreed in IEEE 802.16p AWD.
Notice
Release
Patent
Policy
This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It
represents only the views of the participants listed in the “Source(s)” field above. It is offered as a basis for
discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material
contained herein.
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution,
and any modifications thereof, in the creation of an IEEE Standards publication; to copyright in the IEEE’s name
any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s sole
discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The
contributor also acknowledges and accepts that this contribution may be made public by IEEE 802.16.
The contributor is familiar with the IEEE-SA Patent Policy and Procedures:
<http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and
<http://standards.ieee.org/guides/opman/sect6.html#6.3>.
Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and
<http://standards.ieee.org/board/pat>.
Time-Sharing STID Addressing Scheme
Ming-Hung Tao, Ying-Chuan Hsiao
ITRI
1 Introduction
As mentioned in current AWD, the STID is used to identify the M2M devices in the domain of the ABS.
However, the current addressing scheme associated with the 12-bit STID could make it very difficult to satisfy
the requirement of “Large Number of Devices” in IEEE 802.16p. Therefore, a new addressing scheme without
changing the length of STID is desired for IEEE 802.16p.
1
IEEE C802.16p-11/0068
2 Time-Sharing STID Addressing Scheme
The base station can recognize a device as an M2M device through the capability negotiation process, and
assign the STID to the M2M device through the registration process. During the registration process, the base
station shall send the AAI-REG-RSP message including at least ‘STID’, ‘Valid Periodicity’, and ‘Valid Offset’
parameters to the M2M device message as the response to the AAI-REG-REQ message, as shown in Figure 1.
In case that the base station decides to assign a STID which is already assigned to or is going to be assigned to
other M2M devices, it shall assign a value which is larger than ‘1’ to Valid Periodicity; otherwise, the base
station shall assign the value ‘1’ to the Valid Periodicity . The base station shall always assign a value which is
smaller than Valid Periodicity to the Valid Offset. It should be noticed that for the M2M devices sharing the
same STID, their Valid Periodicity values shall be identical, and their Valid Offset values shall be different from
each other.
M2M Device
Base Station
Capability
Negotiation
Key
Exchange
AAI-REG-REQ
AAI-REG-RSP
(STID, Valid Periodicity,
Valid Offset)
Figure 1. Message exchanges between the M2M device and the BS during the network entry procedure.
If a STID is shared by multiple M2M devices, each M2M device can only apply this STID as its device
identifier in certain time periods (frames), depending on its assigned Valid Periodicity and Valid Offset values.
To be more specific, the M2M device can apply the STID as its device identifier whenever the following
condition is met.
Framenum mod Valid_Peri odicity  Valid _ Offset
,
(1)
where Framenum denotes the current frame sequence number of the system. The M2M device shall not use the
STID if condition (1) is not met.
To receive unicast downlink traffic, an M2M device will monitor the assigned STID at the frame where
the STID is valid for the M2M device according to condition (1). On the other hand, whenever the BS has
unicast downlink traffic pending for an M2M device, it shall allocate the traffic to the M2M device at the frame
where the STID is valid to the M2M device. If the BS is going to allocate an uplink transmission opportunity to
an M2M device, it shall also allocate the opportunity to the M2M device via STID at the frame where the STID
is valid for the M2M device.
If an M2M device needs more bandwidth for uplink transmission, according to the IEEE 802.16m
standard, it shall firstly signal a ranging code to request an uplink transmission opportunity for submitting its
bandwidth request message. After successfully decoding the ranging code, the BS will grant an uplink
transmission opportunity to the device signaling the ranging code; then the device can utilize the opportunity to
submit its bandwidth request message including the STID of the device and the size of the required bandwidth.
2
IEEE C802.16p-11/0068
The bandwidth request message also includes a Valid Offset parameter so that the BS can know which M2M
device is requesting the bandwidth while the STID is shared by multiple M2M devices. After recognizing which
M2M device is requesting the bandwidth and how much bandwidth the device needs, the BS then grants the
corresponding uplink transmission opportunity to the M2M device at the frame where the STID is valid to the
M2M device. Figure 2 illustrates the example for the bandwidth request procedure.
M2M Device
Base Station
(Valid Periodicity = 5, Valid Offset = 1)
Ranging code
frame #10
Opportunity for BR
BR message
(STID, BR size, Valid Offset)
frame #11
.
.
.
Opportunity for uplink traffic
frame #16
Uplink traffic
(16 mod 5 =1)
Figure 2. Bandwidth request procedure for M2M device.
Whenever a BS receives a packet from an M2M device, it shall determine the Valid Periodicity and
Valid Offset of the device based on the STID and the current frame sequence number. Then if the BS has any
response to the received packet, it shall wait a time period equal to n * Valid Periodicity frames and then
transmits the response to the M2M device, where n > 0.
BS receives a packet from an M2M device at
frame #i, and determines the Valid Periodicity
and Valid Offset of the M2M device.
If the BS has a response/ack to the received
packet, it shall wait n*Valid Periodicity frames
then send the response to the M2M device (n>0).
generate response
BS
M2M
device
RSP
RSP
Valid Periodicity * n
frame i frame i+1
frame i + n * Valid Periodicity
Figure 3. BS transmits the response to the M2M device for the received packet.
The BS may be able to know the application type of an M2M device during or before the registration
process. Some M2M applications can tolerate long traffic delay while some M2M applications can allow only
3
IEEE C802.16p-11/0068
very limited traffic delay. Therefore, the BS should assign the value of Valid Periodicity to an M2M device
according to device’s application type. The BS should assign a small Valid Periodicity to the M2M device with
delay-sensitive application and assign a large Valid Periodicity to the M2M device with delay-tolerable
application. Once the BS associates a STID with a Valid Periodicity value, the other M2M devices sharing the
same STID will be assigned the same Valid Periodicity value. Since the Valid Offset for each M2M device
sharing the same STID shall be unique, we can say that the value of Valid Periodicity represents the maximum
number of M2M devices that can share the STID.
3 Text Proposal
Adopt the following text modifications (insert the blue text) to IEEE P802.16p AWD:
--------------------------
Begin Text Proposal
-------------------------------
[Remedy #1: Insert the following text to page 3, line 20]
16.2.1.2 Logical Identifiers
16.2.1.2.1 Station Identifier (STID)
The STID is used to identify the M2M devices in the domain of the ABS. The ABS may assign the same STID
to multiple M2M devices.
In addition to STID, the ABS also assigns Valid Periodicity and Valid Offset parameters to the M2M device to
indicate in which frames the STID is valid to the M2M device. The M2M device recognizes the STID assigned
by the ABS as its STID only when the following condition is met.
Framenum mod Valid_Periodicity = Valid_Offset,
where Framenum denotes the current frame sequence number of the ABS. The M2M device shall not use the
STID if the above condition is not met.
[Remedy #2: Insert the following text to page 3, line 40]
16.2.2.1.3.1 Bandwidth Request (BR) with STID Header
Syntax
Valid Offset
Table 657—BR with STID header format
Size (bit)
Notes
TBD
Valid Offset of the M2M device which
requests UL bandwidth
[Remedy #3: Insert the following text to page 3, line 61]
16.2.3.9 AAI-REG-RSP
Field
Valid Periodicity
Table 686—AAI-REG-RSP message Field Description
Size (bits) Value/Description
Condition
TBD
The Valid Periodicity together
Shall be included when an M2M
with Valid Offset indicates at
device is performing initial
which frames the assigned STID
network entry or an M2M device
is valid for the M2M device
has no STID pre-assigned when
4
IEEE C802.16p-11/0068
Valid Offset
TBD
The Valid Offset together with
Valid Periodicity indicates at
which frames the assigned STID
is valid for the M2M device
----------------------------- End Text Proposal
it is performing network reentry
precedure
Shall be included when an M2M
device is performing initial
network entry or an M2M device
has no STID pre-assigned when
it is performing network reentry
precedure
----------------------------------
4 Reference
[1] IEEE 802.16p-10/0004r2: IEEE 802.16p Machine to Machine (M2M) System Requirements Document
(SRD).
[2] IEEE 802.16p-10/0018r1: IEEE P802.16p Amendment Working Document (AWD).
[3] IEEE 802.16p-10/0005r1: Machine to Machine (M2M) Communications Technical Report.
[4] IEEE P802.16m/D12, Draft Amendment to IEEE Standard for Local and Metropolitan area Networks.
5