Re: [STDS-802-16] [802.16p][DEV RG] Reliability of Multicast Operation for M2M

[Jeongki Kim <jeongki.kim@LGE.COM>]

Dear Kaushik and 16p members,

 

Kaushik, thanks a lot for your efforts.

 

As Kaushik mentioned, I have already been discussing the issue of multicast operation for 16p with other contributors (0006, 0029) in order to make basic harmonized texts on this issue.

 

Regarding the reliable multicast transmission,

My opinion for both methods which Kaushik mentioned is as follows:

1.       Method 1: Retransmission without feedback (e.g., N-th time repetitions like 16e MBS)

A.        Advantage: Reliability may be provided without any feedback overhead

B.       Disadvantage:

                                     i.              Increase the fixed DL resource overhead by N-th TX. That is, although all devices belonging to a multicast group receive the multicast data successfully, multicast data will be retransmitted.

                                   ii.              Incomplete reliability. Due to no feedback ABS does not know who received the data successfully. That is, some AMS devices may miss the data.

C.       Desirable applications: Pre-scheduled real-time traffics such as MBS (e.g., video service (TV), audio service (Radio), etc.)

2.       Method 2: Retransmission with feedback

A.        Advantage

                                     i.              Efficient resource usage. Retransmission happens only when there is feedback.

                                   ii.              Providing full reliability.

B.       Disadvantage

                                     i.              Need UL feedback overhead (I think this overhead is not big because robust MCS is basically used for multicast transmission.)

C.       Desirable applications: Multicast traffic which needs full reliability like M2M multicast data. E.g.) Application management data to control the all devices belonging to a group remotely, software update data, etc.

 

Please note that the method 2 is not an alternative solution of method 1. Regardless of using method 1, method 2 needs to be used for reliable M2M multicast transmission.

For example, when a device does not receives the N-th retransmitted multicast data without feedback, if the device informs BS of it and BS again transmits the multicast data, the better reliability will be provided for the multicast transmission.

 

Thanks,

Jeongki

 

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From: Kaushik Josiam [mailto:kjosiam@STA.SAMSUNG.COM]
Sent: Thursday, February 10, 2011 5:30 AM
To: STDS-802-16@LISTSERV.IEEE.ORG
Subject: [STDS-802-16] [802.16p][DEV RG] Reliability of Multicast Operation for M2M

 

Dear 16p members,

There was general consensus on multicast operation for 16p.  Mr. Jeongki Kim of LGE has volunteered to lead the harmonization efforts to come up with a basic text for Multicast operation working with other contributors to the topic.  

He will advise the group when the harmonized text is ready, so we can review it.

 

In discussing multicast operation for M2M today, we agreed that the reliability should be a key feature for M2M downlink multicast.   In particular, there were two approaches outlined for making multicast operation reliable – one with feedback and one with repetition and no feedback.  If you have proposals for the group to consider on this issue, please share and discuss them in this email chain.

 

Thank you for your cooperation

 

Regards

Kaushik & Ming-Hung

DEV RG Chairs