Re: [STDS-802-16] 802.16 multicast / broadcast support

[Mark Thomas <mthomas@AIRSPAN.COM>]

Hi,

It's useful to remember that DSX messages are sent as unicast management
messages, even when they are used to set up a multicast connection. It
the BS needs to delete a service flow that is associated with a
multicast connection, the BS must generate one DSD exchange for each
participating SS.

Mark 

-----Original Message-----
From: Pedro Neves [mailto:pneves@AV.IT.PT] 
Sent: 19 December 2005 00:45
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] 802.16 multicast / broadcast support

Jeff Mandin wrote:

>Pedro,
>
>Where do you see that "DSA-REQ message requires the MAC address of the
>SS to which the service flow is going to be created"?   6.3.2.3.10
>describes DSA-REQ fields and does not include the SS MAC address.
>
>  
>
Sorry for the mistake. In fact the SS MAC address is only used on the
MAC_CREATE_SERVICE_FLOW.request primitive sent by the CS layer to the
MAC layer. Then, as you said, the DSA-REQ message does not contain the
SS MAC address. But it contains an identifier of the SS to which the
reservation should be done - the SS's Primary Management CID in the
Generic MAC Header. If you look at section "/6.3.13 - Establishment of
multicast connections/", it describes the following: "/The BS may
establish a downlink multicast service by creating a connection with
each SS to be associated with the service. Any available traffic CID
value may be used for the service (i.e., there are no dedicated CIDs for
multicast transport connections). To ensure proper multicast operation,
the CID used for the service is the same for all SSs on the same channel
that participate in the connection./" It makes sense because if you do
not somehow specify the destination SS, how does the BS knows to whom
the reservation should be done? Please, let me know what I am doing /
thinking wrong on order to clarify my mind.

Thanks.

Pedro

>- Jeff
>
>On 12/18/05, Pedro Neves <pneves@av.it.pt> wrote:
>  
>
>>Hello Jeff,
>>
>>Thanks for the prompt answer.
>>
>>Please see inline.
>>
>>Jeff Mandin wrote:
>>
>>    
>>
>>>Pedro hi,
>>>
>>>
>>>On 12/18/05, Pedro Neves <pneves@av.it.pt> wrote:
>>>
>>>
>>>      
>>>
>>>>Dear all,
>>>>
>>>>I have a doubt related with multicast / broadcast and I was not able

>>>>to understood it from the standard. Suppose that I have one Base 
>>>>Station
>>>>(BS) and three Subscriber Stations (SS1, SS2 and SS3). Suppose that 
>>>>I am using 802.3 classification and I want to forward a multicast 
>>>>flow through SS1 and SS3. From what I understood from the standard, 
>>>>I must establish a service flow between the BS and SS1 with, for 
>>>>example, CID = 1. This service flow between BS and SS1 is 
>>>>established based on the multicast MAC address of the multicast 
>>>>flow. Then, I must establish an identical service flow between the 
>>>>BS and the SS3 also with CID = 1 and with the same classification 
>>>>procedure (multicast MAC address of the multicast flow). Is this
correct or am I wrong?
>>>>
>>>>
>>>>
>>>>        
>>>>
>>>Basically correct.  But it's a single SF that you make available to 
>>>each of the 3 SS (not 3 SFs).
>>>
>>>
>>>      
>>>
>>I see. But I still have a doubt. From the standard, we can see that 
>>the DSA-REQ message requires the MAC address of the SS to which the 
>>service flow is going to be created. Thus, I thought that each service

>>flow was created to a specific SS and not to a group of SSs. I was not

>>aware that the BS could create a service flow without indicating the 
>>SS that the service flow is for. How can we do it? Not indicating the 
>>MAC address of the SS in the DSA-REQ message? But we should somehow 
>>indicate which are the SSs that should belong to the multicast group.
>>
>>    
>>
>
>
>
>  
>
>>Once again, thanks for the help.
>>
>>Regards,
>>Pedro Neves
>>
>>    
>>
>>>      
>>>
>>>>Concerning broadcast, should the procedure be the same? Should I 
>>>>establish one service flow between the BS and each one of the SSs 
>>>>with the same CID and using the FF:FF:FF:FF:FF:FF MAC address?
>>>>
>>>>
>>>>
>>>>        
>>>>
>>>Yes.
>>>
>>>
>>>
>>>      
>>>
>>>>Thanks in advance for your help.
>>>>
>>>>Best Regards,
>>>>Pedro Neves
>>>>
>>>>
>>>>
>>>>        
>>>>
>>    
>>