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Dear Hyunjeong and all,
Thanks for your question. Yes, I think 16p system should
support 30000 M2M devices in connected state.
In SRD 6.2.9, it says "The 802.16p system shall support large numbers of M2M devices in connected state as well as in
idle state." Unfortunately, it is not clear how "large"
should be. We provide the value of 30000 by our experience. I also agree
with you that 1000 devices could be burden for 16m/16e base station, but I don't
agree 1000 is "large".
I believe this discussion is to seek consensus on
the number of connected devices. If people think 30000 is too large, I
appreciate they could provide their suggestions.
Best Regards,
Yi-Ting
From: Hyunjeong Kang
Sent: Friday, February 11, 2011 1:27 PM
Subject: RE: [STDS-802-16] [802.16p][DEV-RG] - Email Discussion on
M2M device identification Dear Yi-Ting and all, Yi-Ting, Thank you for your information. I have a question based on Yi-Ting’s
information. I understand there are more than 30,000 M2M devices in a cell, but I
wonder it is feasible to assume that 30,000 M2M devices are in connected state.
Because we are discussing the addressing space to be used in connected
state. Do you think that 30,000 M2M devices stay in communication mode with
a base station? In my thought, it is too burden for a base station to manage more
than 1,000 devices in connected state. Regards, Hyunjeong From:
林奕廷 (Lin,
Yi-Ting) [mailto:eating@NMI.III.ORG.TW] Dear
all, Thanks
for Chiwoo's analyses. We agree that, with current 16m feedback
channel design, the maximum number of devices would be 12032.
We would like to
share our experiences on smart meters in Taipei. Please refer to the
file <http://www.3gpp.org/ftp/tsg_ran/WG2_RL2/TSGR2_70/Docs/R2-103269.zip> for
reference. For a cell of 1 km radius, the number of smart meters could be
more than 30000. In practice it is not likely all smart meters attach
to the network at the same time. But, considering various M2M
applications would run simultaneously in a cell, we think the value
of 30000 is reasonable to be the baseline number of supported
devices. Best
Regards, Yi-Ting From: Lim Chiwoo
Sent: Friday,
February 11, 2011 10:08 AM Subject: Re:
[STDS-802-16] [802.16p][DEV-RG] - Email Discussion on M2M device
identification Dear
16p members, As
Kaushik pointed, we couldn’t agree on how many devices we need to support or how many devices we
can currently support. According to addressing issue, it’s required to determine this first. I want
to show my calculations about current feedback capacities of 16m and 16e.
I think
that the size of STID doesn’t need to largely exceed the capacity of feedback channel because
operation is not guaranteed if there is no relevant feedback.
The
results show that the number of supportable user based on feedback channel are
7168/12032/200 in cases of 16m(10MHz)/16m(20MHz)/16e(10MHz), respectively.
I think
that we can consider these results when we determine the number of devices to be
supported in M2M. Please
let me know your opinion. Please
see following calculations. Basic
conditions - DL:UL =
5:3 - One
feedback channel makes 6 HARQ feedback channels. - Maximum
number of LRUs for feedback channel : 16 (4 bits indication)
- Maximum
number of HARQ feedback channel is 30/60 for 10/20MHz, respectively.
- Let’s consider maximum HARQ feedback channel.
- The
report period of fast feedback channel is up to 128 frames (=640ms, 3 bits
indication) - <10MHz case, 16m> There
is a restriction of number of feedback channel. The MAX number is 27.
(per one subframe) 5
feedback channels are used for HARQ feedback channels. (per one DL subframe (one
HARQ feedback region)) There
are 81 (= 27 * 3) feedback channels per one frame. 25
(=5*5) feedback channels are used for HARQ feedback channel.
That
is, there are 56 fast feedback channels in a frame. When we
consider the report period as 8/32/128 frames, the number of supportable
user are 448/1792/7168. <20MHz case, 16m> There
are 48 feedback channels. (per one subframe) 10
feedback channels are used for HARQ feedback channels. (per one DL subframe (one
HARQ feedback region)) There
are 144 (= 48 * 3) feedback channels per one frame. 50
(=10*5) feedback channels are used for HARQ feedback channel.
That
is, there are 94 fast feedback channels in a frame. When we
consider the report period as 8/32/128 frames, the number of supportable
user are 752/3008/12032. <10MHz case, 16e> In 16e,
the report period of CQICH channel is up to 8 frames (= 40ms, 2bits indication)
There
are 35 subchannels per one frame in 10MHz. 6
subchannel shall be used as ranging channel. Therefore, if we assume 25 subchannels for CQICH and 4 subchannels
for ACK/NAK, the number of supportable user is just 200.
BR,
Chiwoo From: Kaushik
Josiam [mailto:kjosiam@STA.SAMSUNG.COM] Dear 16p
members In the
DEV RG conference call today, we wanted to hear the member’s view on how many
devices we need to support in 802.16p systems. We can increase the
addressing space to support a large number of users, but in the conference call,
we couldn’t agree on how many devices we need to support or how many devices we
can currently support. Related
to this issue, do we need to define a new M2M specific IDs for M2M
devices? If you
have any thoughts or proposals on the issue, please share them as a reply to
this thread. We thank
you for your cooperation. Regards Kaushik
& Ming-Hung DEV RG
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