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Re: [STDS-802-16] [802.16n][MM][MultiMode] Discussion on Relay Function for HR-BS for OFDMA Air Interface



Hi Eunkyung, All

 

Thanks for initiating the discussion, please see my comments below. Hope this helps,

 

Eldad

Office   +1 631 622 4134

Mobile +1 631 428 4052

Based in NY area

 

From: Eunkyung Kim [mailto:ekkim@etri.re.kr]
Sent: Thursday, April 14, 2011 9:07 AM
To: STDS-802-16@LISTSERV.IEEE.ORG
Subject: Re: [STDS-802-16] [802.16n][MM][MultiMode] Discussion on Relay Function for HR-BS for OFDMA Air Interface

 

Hi Anh Tuan, Alina and multimode fans,

 

Thank you, Alina, for initiating the email discussion and Anh Tuan, for clarification the issues.

I agree with Anh Tuan that we need technical element discussion at first.

Please see my inline comment and let me know anything is missed or wrong.

 

Best Regards,

Eunkyung Kim

Electronics & Telecommunications Research Institute (ETRI)

 

-----Original Message-----
From: Hoang Anh Tuan [mailto:athoang@I2R.A-STAR.EDU.SG]
Sent: Thursday, April 14, 2011 12:42 AM
To: STDS-802-16@LISTSERV.IEEE.ORG
Subject: Re: [STDS-802-16] [802.16n][MM][MultiMode] Discussion on Relay Function for HR-BS for OFDMA Air Interface

 

 

Dear Alina,

 

Thank you for initiating the discussion. I think we may not want to work directly on the proposed text, as it will be difficult to manage if different people want to modify the same text in different ways. Rather, I propose that we focus on underlying technical elements of the topic. For multi-mode, we may need to collect opinions on:

 

- What are the trigger conditions of mode changes, and who can initiate the changes?

[ekkim] condition may be issues of implementation. However, following is reasonable condition, I think.

-          When backhaul is unavailable temporally or some specific time (which is the condition for HR-BS acting as HR-RS)

-          When there is no infrastructure station [Eldad: and no forwarding HR-MS]  (which is for HR-MS acting as HR-BS)

-          When it is needed to relay some data between stations (which is for HR-MS acting as HR-RS)[Eldad: this in itself isn't a sufficiently clear condition as normally the HR-BS can forward the data if those two HR-MS are attached to it. A better definition should be helpful here]

 

- What is a mode change anyway? Is it a clean switch between two (BS/RS/MS) roles or a station can perform a combined/dual role?

[ekkim] we need to define the topologies at first. However, HR-MS acting as HR-RS/HR-BS has to maintain MS and RS/BS functionalities at the same time.

[Eldad] I’m not sure what is the functionality of HR-MS that has to be maintained while it is an HR-BS or HR-RS. The only one that comes to mind is the ability to provide local source and sink. Is that your intention? It has always been my opinion that local source and sink capability doesn’t require a standards change. We do however already have this requirement for the HR-RS.

 

- What are the supported topologies after a mode change, assuming 16e or 16m baselines?

[ekkim] What I think the backward compatibility is the main concern. Thus, even the role changes, the topology should be a line of 16e or 16m.

 

- What are the steps taken during/after a mode change?

[ekkim] HR-BS or HR-MS acting as HR-RS is a little clear relatively comparing with HR-MS acting as HR-BS.

Following is the expected steps for mode change to relay station.

Step1. Informs subordinate stations that  mode change starts

Step2. Establishes relay link including configuration

Step3. Informs explicitly or implicitly subordinate stations that mode change is done

In addition, HR-MS acting as HR-BS may start BS operation by itself when any base station is not detected. Any other condition is FFS.

 

- Should mode change always be regarded as temporary? and if that is the case, what is the time scale, in comparison to that of a MS connection?

[ekkim] I don’t catch what you mean.

[Eldad] My thinking is that role change isn't permanent i.e. an HR-station that has changed its role can revert to its original role. I think the decision and conditions to do so should be left to implementation. We may choose to specify signaling to support it though.

 

That is just my opinion, and I am open to other approaches.

 

Very sorry for the plain text message as I have difficulty in sending HTML mail through Outlook Web Access. I am trying to fix this.

[ekkim] Thanks and I am looking forward to fixing it asap. :)

 

Best regards,

Anh Tuan

 

 

 

________________________________

 

From: Lu Liru, Alina [mailto:liru@nict.com.sg]

Sent: Wed 4/13/2011 4:01 PM

To: STDS-802-16@LISTSERV.IEEE.ORG

Subject: [STDS-802-16] [802.16n][MM][MultiMode] Discussion on Relay Function for HR-BS for OFDMA Air Interface

 

 

 

 

 

Dear 16n participants,

 

 

 

This email is to initiate the discussion for Multi-mode operation for the topic Relay Function for HR-BS for OFDMA Air Interface

 

The following texts in Blue provides the consolidated texts based on each party's proposal for the above topic. If you disagree certain point, please highlight the texts. and provide alternative texts in different color subsequently. If you want to insert texts, please use INSERT[***]. Please make the modification based on the VERSION I texts provided below. We shall work on the same version of texts and I will collect all your inputs and form a VERSION II if any. Thank you for your cooperation!

 

 

 

********************************************************** VERSION I:  <<Relay function for HR-BS>>**********************************************************

 

17.2.1.a HR-MS Multi-mode capability registration

 

A HR-MS that is capable of role change to HR-RS and/or HR-BS shall register this capability to the super-ordinate HR-BS at network entry, together with the basic capability negotiation phase. HR-MS should indicate to the super-ordinate HR-BS if it is unavailable to perform a role-change.

 

 

 

17.2.1.b Relay function for HR-BS

 

HR-Network shall support HR-BS communication with another HR-BS in order to support the relaying function to provide continuous network connectivity.

 

HR-BS shall operate a relay function to support the relaying of messages when its backhaul communication is unavailable or when relay support is requested from HR-MS. The HR-BS acting as RS mode can operate in either TTR mode or STR mode.

 

The procedures for RS mode change consist of three steps:

 

a) inform subordinate MSs that backhaul services are unavailable

 

b) establish a relay link with a neighbor HR-BS

 

c) reconfigure the physical frame

 

Prior to/during/and after carrying out mode switching, the HR-BS shall perform appropriate PHY-level configurations and MAC-level control/signaling to maintain connectivity for its subordinate stations.

 

The origin cell HR-BS shall use its relay function to communicate with the HR-BS in the destination cell to enable the communication between stations covered within two cells. HR-BS shall maintain its BS functionality such as central scheduling even when it is operating its relay function. If the HR-BS recovers from the failure of backhaul, it informs network or notifies neighbour HR-BS through the backhaul network interface.

 

The HR-BS may transmit MAC context information (e.g., path information) of the HR-MSs during establishing relay link to neighbour HR-BS to allow HR-MS to select alternative path.

 

 

 

********************************************************** ENG of VERSION I:  <<Relay function for HR-BS>>**********************************************************

 

 

 

 

 

Best regards,

 

 

 

Alina Liru LU (? ??), Ph.D

 

Research Scientist

 

Wireless Communications Laboratory

 

National Institute of Information and Communications Technology

 

Tel: (65) 6771 1006

 

Fax: (65) 6779 5753