[STDS-802-16] [HO] Usage of "network assisted HO supported flag"
Hi,
I have one question about the usage of Network
Assisted HO supported flag in MOB_BSHO-REQ message and MOB_BSHO-RSP
message. In my understanding, if Network Assisted HO supported flag is
set to "1" in MOB_BSHO-REQ or MOB_BSHO-RSP message, MS may perform a
handover to any BS among the recommended BSs without MOB_HO-IND.
However, according to section 6.3.2.3.55 of IEEE 802.16e-2005, an MS
"shall" transmit a MOB_HO-IND message for final indication that it is
about to perform a HO. It seems that there is conflict between the
usage of MOB_HO-IND and the usage of Network Assisted HO supported
flag.
There are two possibilities of the above issue:
(1) An
MS shall transmit a MOB_HO-IND message for final indication even though
the Network Assisted HO supported flag is set to "1", i.e. MS behavior
has no difference between Network Assisted HO supported flag is set to
0 and 1. In this case, why we still need Network Assisted HO supported
flag? What does it mean to MS?
(2) An MS may perform a handover to any BS among the
recommended BSs without MOB_HO-IND. Note that in this case, the MS MAY
send MOB_HO-IND with target BS ID = "0x00000000" as an acknowledgement
to the MOB_BSHO-REQ message but may not send MOB_HO-IND during actual
HO. However, this case incurs another issue: if there is no MOB_HO-IND
before MS starts HO, how does the Resource retain timer work in this
case? Without Resource retain timer, how can the MS decide that it can
cancel HO except in the drop case?
I appreciate any comments and discussion on this issue.
thanks,
==========================================
Chi-Chen Lee
Design Engineer
Wireless System Technology Div.,
SoC Technology Center(STC),
Industrial Technology Research Institute
Tel: +886-3-5914579
Fax: +886-3-5829733
E-mail: jjlee@itri.org.tw
http://www.stc.itri.org.tw/
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