I mean that certain BS should not have the
option of being and Anchor. Some sort of mechanism for the anchor to be other
than the currently connected BS would be needed to support FBSS or soft
handoff. But a Pico cell with limited backhaul would not be a good candidate
for the anchor. Some type or rating in the AI messages to tell the MSS that
this station cannot do this possibly even recommending another BS for the
purpose.
-----Original Message-----
From: Mary Chion
[mailto:mchion@ztesandiego.com]
Sent: Tuesday, August
03, 2004 5:07 PM
To: Mcginniss, Dave S [NTK];
STDS-802-16-MOBILE@listserv.ieee.org
Subject: RE: [STDS-802-16-MOBILE]
[Harmonization] Question for FBSS
I think the issues you
raised are cruicial ones. I would like to try to address some of them here.
1. H_Add and H_Delete are
parameters included in DCD message. They are set by the network and broadcast
to all the MSS in the BS.
2. Active set is part of
of contribution for FBSS and SHO and it is adopted in the 802.16e.
3. You are correct, there
should be a limit in the number of BSs allowed in the active set. It can
be done by one of the two ways:
a)
Since the BS is involved in the HO process, the BS can limit the number of
BSs in the active set without changing the standard. When the MSS send MOB-MSSHO-REQ
message to the BS, the BS will send the new active set information to the MSS
in MOB-BSHO-RSP message and BS can limit the number of BS in the active set in
the message. It is stated in the standard that "the actual Active Set chosen by the
MSS shall be a subset of those listed in MOB_xxxHO-RSP and shall be indicated
in MOB-HO-IND".
b) We can
specify the maximum number of BSs in active set in the standard. But, this
might not be necessary.
4. An Anchor BS is defined as one of the BSs in the active
set. The role of Anchor BS in Fast BS Switching is to be the only BS
communicating with the MSS. What's added in the standard is only
addressing the over-the-air interface. I'm not sure if I fully understand what
you mean by excluding a BS to be the anchor BS. For FBSS, an anchor BS is
necessary for the HO scenario. I agree with you, if the same data are sent to
all BSs in the active set BS instead of just to the anchor BS, there
will be a major impact on backhaul capacity (especially for services
with high speed data) and it might not even be an accpetable implementation. This
is an important issue for network design. However, I don't think we can address
this issue in 802.16e since 802.16e only defines the over-the-air interface. This
should be resovled at system implentation.
Please let me know what
you think. Thanks.
-----Original
Message-----
From: Mcginniss, Dave S [NTK]
[mailto:david.s.mcginniss@mail.sprint.com]
Sent: Tuesday, August
03, 2004 5:08 PM
To: Mary Chion;
STDS-802-16-MOBILE@listserv.ieee.org
Subject: RE: [STDS-802-16-MOBILE]
[Harmonization] Question for FBSS
In the entire example for
Fast Cell Switching and Soft Handoff I had assumed the anchor was analogous to
a BSC/APC (base station controller/Access Point Controller) Only in a
decentralized implementation without this element would a BS/AP serve as an
anchor. I think the original question posed by Jay form LG is a crucial
one. If all the BS in the active set are served the same data for the MSS
by the Anchor (BS/BSC) this could be a significant impact on backhaul
requirements. Is there a concrete methodology for limiting the active
set? I see the H_ADD and H_Delete messages but cant see where they are
set. The Neighbor list can have 255 BS in it. The 802.16E/D4 has a
lot of information to support FBSS and soft handoff has the active set been
adopted? Should there be a value to set a limit on the number in the
active set? Also should there be a parameter that if set precludes a BS
form becoming an anchor. As an operator I would not want a Pico cell end
node with little backhaul serving as an anchor. If you can set an option
that a BS cannot serve as an anchor and FBSS is to be supported then in
6.3.20.2.6 “When operating in FBSS, the MSS only communicates with the
Anchor BS for UL and DL unicast messages and traffic” is an
incorrect statement.
-----Original Message-----
From:
owner-stds-802-16-mobile@listserv.ieee.org
[mailto:owner-stds-802-16-mobile@listserv.ieee.org] On Behalf Of Mary Chion
Sent: Monday, August
02, 2004 9:21 AM
To:
STDS-802-16-MOBILE@listserv.ieee.org
Subject: Re: [STDS-802-16-MOBILE]
[Harmonization] Question for FBSS
This is
Mary Chion. Sorry about the late reply.
In
FBSS, only one BS will be communicating with the MSS at any time instance
(the anchor BS). The BS can choose one of the BS in the active set to be the
anchor BS through MOB-BSHO-REQ/RSP message. Once the MSS confirms the HO
with MOB-HO-IND, The MSS should only expect trasmission from the anchor BS.
Regarding
the question of which BS have the data, it's really an implementation
issue, it also depends on what kind of network architecture you will be using.
If your network architecture includes a control point for the BSs (i.e. BSC),
the control point can buffer the data and only send to current anchor
BS. When a new anchor BS is chosen, the conotrl point will just
redirect the traffic. With distributed system, the anchor BS should be resposible
for the data. When the ahcnor BS is changed, the old anchor BS can forward
data to the new anchor BS. The above scenarios are only examples, the
implementatios can be different from each company and should not be specified
in the standard.
-----Original
Message-----
From:
owner-stds-802-16-mobile@LISTSERV.IEEE.ORG
[mailto:owner-stds-802-16-mobile@LISTSERV.IEEE.ORG]On Behalf Of Inkyu Paek
Sent: Monday, August
02, 2004 7:00 AM
To:
STDS-802-16-MOBILE@LISTSERV.IEEE.ORG
Subject: Re: [STDS-802-16-MOBILE]
[Harmonization] Question for FBSS
To my knowledge, all BS's in an active set share same
data for an MSS.
----- Original Message -----
Sent: Monday, August 02, 2004 5:26 PM
Subject: [STDS-802-16-MOBILE] [Harmonization]
Question for FBSS
I have a quick question for my clarification.
I wonder which BSs are responsible for having Data for
an MSS in FBSS(Fast BS Switching).
Do all BSs in active set have to share same data for
an MSS?
Only a serving BS has data for an MSS then forwards
the data to an anchor BS?
Thanks in advance.
Best regard.
jay
--------------------------------------------
Yongseok (jay) Jin
Research Engineer
Standards & System Research Group
Mobile Communication R&D Center, LG Electronics Inc.
--------------------------------------------
Phone:+82-(0)31-450-7187
Mobile:+82-(0)11-9953-3149
Fax:+82-(0)31-450-7912
e-mail: jayjay@lge.com
---------------------------