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Re: [STDS-802-16-MOBILE] [handoff]Periodic Scanning

Dear Avi.
 
First of all, thanks for your reply, and you can call me kihyoung, it's my given name. =)
I agree with you in that 'BS controlled handover' shows better performance in load balancing, management of BS's radio resource and so on. It is also ture that most well known cellular systems such as 3GPP and 3GPP2 adopt this philosophy. But, onething I'm afraid is that we don't have any entity, such as BSC or RNC, which can control each BS. I think that we have to discuss the network architecture before opening the issue of 'BS controlled handover'.(network architecture will be discussed in Network Management group. right?)
Regarding the parameters such as SCAN DURATION, NORMAL OPERATION PERIOD, and SCAN ITERATION..( the last two are proposed parameters in my contribution, A method of scanning neighbor BSs periodically-rev2.pdf, which is in server)
Yes, those parameters will change rather slowly depending on the mobile speed. But, I think that because every MSS suffers different channel changes, every different MSS may request different value. Of course final value will be decided by BS. The MSS only gives some information about its preference.
It seems to me that most values(scan duration, sleep interval, listening interval..) in IEEE802.16e are firstly requested by MSS and then decided by BS. I think that those proposed parameters, NORMAL OPERATION PERIOD and SCAN ITERATION, are also similarly treated with other parameters.
 
B.R
kihyoung
--------------------------------------------
Kihyoung Cho
Research Engineer
Standards & System Research Group
Mobile Communication R&D Center, LG Electronics Inc.
--------------------------------------------
Phone:+82-(0)31-450-2945
Mobile:+82-(0)11-738-3895
Fax:+82-(0)31-450-7912
e-mail: kihyoung@lge.com
---------------------------
----- Original Message -----
Sent: Sunday, June 20, 2004 6:01 AM
Subject: Re: [STDS-802-16-MOBILE] [handoff]Periodic Scanning

Dear  Kihyoung, (or should I say ''dear  Cho", you must tell me sometime)
I believe that leaving the decision for HO entirely to the MSS, or letting the BS do it based on partial information (not including the exact RSSI and CINR but only the rank or a list of preferred BS's)  will lead to sub optimal, if not worst, results. The BS (or rather the system behind it) has better information about the load of other BS's, and can make better decision as  to which BS the MSS should be handed to (or which BS should be added to the active set). It might be OK to allow MSS initiated HO but still, we don't have to encourage it.  I would like to see in the standard a positive statement about the scanning result report. As for the SCAN DURATION and other parameters, these are really parameters that change rather slowly. In my opinion there is no need for them to be adapted to channel conditions in time scales that are smaller than the time it takes for a BS control cycle . Again I think that it is better and simpler to leave it all to the discretion of the BS alone.
Avi
 
----- Original Message -----
From: kihyoung
Sent: Saturday, June 19, 2004 11:10 AM
Subject: Re: [STDS-802-16-MOBILE] [handoff]Periodic Scanning

Dear Feedman.
 
The report of the CINR and RSSI of serving BS can aid in such processes as BS selection/assignment and burst adaptive profile selection as specified in the setion 8.3.8.1 of IEEE802.16d. But, I don't think that the measurements should be ALWAYS reported to the serving BS whenever the MSS measures the CIRN and RSSI. Even though the MSS does not report the results of measurements, those results can be used to decide downlink burst which is request via DBPC-REQ or RNG-REQ. I'm not saying that the report of CINR and RSSI of serving BS is not necessary, but sayng that the result of measurement is meaningful in an MSS without reproting.
--------------------------------------------
Kihyoung Cho
Research Engineer
Standards & System Research Group
Mobile Communication R&D Center, LG Electronics Inc.
--------------------------------------------
Phone:+82-(0)31-450-2945
Mobile:+82-(0)11-738-3895
Fax:+82-(0)31-450-7912
e-mail: kihyoung@lge.com
---------------------------
-----Original Message-----
From: owner-stds-802-16-mobile@LISTSERV.IEEE.ORG [mailto:owner-stds-802-16-mobile@LISTSERV.IEEE.ORG] On Behalf Of Avi Freedman
Sent: Saturday, June 19, 2004 1:43 PM
To: STDS-802-16-MOBILE@LISTSERV.IEEE.ORG
Subject: Re: [STDS-802-16-MOBILE] [handoff]Periodic Scanning

The case the MSS does not report the CINR and RSSI to the BS is not an option. The results of measurements of a single MSS are virtually meaningless.
----- Original Message -----
From: bcihm
Sent: Friday, June 18, 2004 10:36 AM
Subject: [STDS-802-16-MOBILE] [handoff]Periodic Scanning

 

Dear Prakash and all

 

In the last Telecon, the contribution "A method of scanning neighbor BSs periodically-rev2" got some comments.

Regarding the length of the fields in MOB-SCN-REQ message, SCAN DURATION(12bits), NORMAL OPERATION PERIOD(8bits), SCAN ITERATION(8bits), I think that the 12 bits for SCAN DURATION is too long. Because, as it was described in the contribution, 12 bits means approximately 20 seconds for ONE scanning. In my opinion, 8bits are large enough for SCAN DURATION. I think the tens of mille second is proper duration for an MSS to scan ONE neighbor BS, if the length of frame is assumed to 5ms. And also, if we assume that the maximum number of neighbor BSs which should be scanned by an MSS is 19(2 Tiers), the duration for ONE scanning will be less than 950 ms (190 frames = 19x50ms).

In WCDMA-GSM handover of 3GPP, it is recommended for UE(User Equipment) to measure the channel quality of GSM twice in 8 frames. It can be interpreted into that the UE iteratively measures with the period of 40 ms. Real value for the period of scanning should be decided by conformance test, but I think the 8 bits for the NORMAL OPERATION PERIOD is enough(8bits = 1.28ms).

Regarding the reason why the MSS can select the length of NORMAL OPERATION and SCAN ITERATION, in case the MSS does not report CINR or RSSI to serving BS, only the MSS knows the change of the channel. So in this case, the MSS can request the scan related parameters more adaptively to channel change. I guess the other existing parameter such as SCAN DURATION can be also requested by MSS even though the BS allocates final value referring to the requested value.

 

I expect any comment on this issue.

 

B.R

kihyoung

 

--------------------------------------------
Kihyoung Cho
Research Engineer
Standards & System Research Group
Mobile Communication R&D Center, LG Electronics Inc.
--------------------------------------------
Phone:+82-(0)31-450-2945
Mobile:+82-(0)11-738-3895
Fax:+82-(0)31-450-7912
e-mail: kihyoung@lge.com
---------------------------