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Re: [STDS-802-16] Broadcast



I believe we don't require a well-known broadcast CID in the DL. This is
mostly because, as DJ pointed out, broadcast is a service associated with
the CS, and it is highly possible than on the same BS you have terminals
that support one CS using one broadcast CID, and other terminals,
supporting a different CS, using another broadcast CID.
 
In addition to that, the well-known broadcast CID buys you
nothing, because a broadcast connection will still have to be established
on a per terminal basis (because not all terminals need it, and it
interferes with sleep and idle modes, etc.). So if you are already
establishing the connection, there is little extra overhead in providing
a CID to go along with it. This way you keep at the flexibility in terms
of what modulation to use on a broadcast connection, how many of them to
establish, etc.
 
Yigal Leiba
      -----Original Message-----
      From: owner-stds-802-16@LISTSERV.IEEE.ORG
      [mailto:owner-stds-802-16@LISTSERV.IEEE.ORG]On Behalf Of
      Johnston, Dj
      Sent: Wednesday, April 21, 2004 10:14 PM
      To: STDS-802-16@LISTSERV.IEEE.ORG
      Subject: Re: [STDS-802-16] Broadcast

      The issue of data broadcast needs to be understood in the
      context of what CS service you are providing.

       

      Broadcast data (as opposed to broadcast management) is a
      feature of the CS service. So for example 802.1 defines
      broadcast behaviour within the context of 802. This is not
      completely trivial, the behaviour of 802 broadcast data on an
      802 network is subject to a number of rules. The behavior at
      the 802.16 MAC CPS layer is the multicast service.

       

      At present it is the job of the CS to map between the CS
      broadcast service and the MAC CPS multicast service. I
      submitted a few comments about the need to clarify the CS
      broadcast behavior in order to make both ends of the link
      behave the same.

       

      So if a CS is presenting and 802 broadcast service, it needs
      to know who is in the 802 broadcast group and set up a
      multicast group to all these SSs. You may be doing something
      different to the default. There may be VLANs or provider
      bridging or distinct, isolated 802 networks being served to
      users.

       

      So in 802.16, broadcast data is not broadcast data. It is a
      specially managed aspect of the MAC CPS multicast service to
      provide an equivalent to a CS layer broadcast service.

       

      If we want to go down a route of defining broadcast data in
      the MAC CPS, then we need to have a reason.

      E.G.

          A MAC CPS layer broadcast service will enable CS layer
      broadcast service with lower on air management messaging

      or

          A MAC CPS layer broadcast service will prevent redundant
      specification of broadcast behaviour in multiple CS specs.

       

      I don't see that either of these is true. Therefore I don't
      see a need for a broadcast CID on the downlink.

      On the uplink, there is no broadcast. Data goes only to the
      BS, since that is what the PHY layer supports. The CS is free
      to create a multicast CID to provide that function.

       

      So I see no need to a broadcast CID in the MAC CPS.

       

      DJ

       

       
            -----Original Message-----
            From: owner-stds-802-16@listserv.ieee.org
            [mailto:owner-stds-802-16@listserv.ieee.org] On
            Behalf Of Ken Stanwood
            Sent: Wednesday, April 21, 2004 8:48 AM
            To: STDS-802-16@listserv.ieee.org
            Subject: Re: [STDS-802-16] Broadcast

            The basic situation is this:

             

            1.  The "Broadcast" connection that currently
            exists was intended for MAC usage.  There is now
            way to indicate a user service over it.

            2.  Multicast polling groups are just that,
            polling groups, not connections.  The "CID" is a
            replacement for the SS's Basic CID which is
            actually used in maps a a shortened SS ID rather
            than really a connection ID.

            3.  Terminals are unaware whether a connection is
            multicast or unicast, with the exception of it
            having a different security association.

            4.  A broadcast DL connection would be
            established today by setting up a connection with
            the same parameters to all SS's.  It's data would
            need to be transmitted in a region that all SS's
            could listen to, or be re-broadcast to sets of
            SS's if no such region existed as could possibly
            happen with AAS or DL OFDMA.

             

            We should consider whether a true broadcast
            well-known connection would be useful.  If so, I
            recommend putting it in 16e since it's an extra
            feature.

             

            Ken


________________________________________________________________________________

            From: owner-stds-802-16@listserv.ieee.org
            [mailto:owner-stds-802-16@listserv.ieee.org] On
            Behalf Of Pedro Neves
            Sent: Wednesday, April 21, 2004 4:42 AM
            To: STDS-802-16@listserv.ieee.org
            Subject: Re: [STDS-802-16] Broadcast

            The draft does not specify one broadcast and one
            multicast connection for sending data from the BS
            to the SS's?

             

            As Vladimir said, multicast polling groups are
            used, but what about data transfer from the BS to
            the SS's? I thought CIDs were allocated for this
            type of transmissions.

             

             

            Regards,

            Pedro Neves

             

            --------------------------------------------------------------------

            Pedro Miguel Naia Neves

            Instituto Telecomunica^Í^Ûes
            - http://www.av.it.pt

            Aveiro - Portugal

            Phone: +351 234 377 900

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________________________________________________________________________________

            From: owner-stds-802-16@listserv.ieee.org
            [mailto:owner-stds-802-16@listserv.ieee.org] On
            Behalf Of Vladimir Yanover
            Sent: quarta-feira, 21 de Abril de 2004 12:06
            To: STDS-802-16@listserv.ieee.org
            Subject: Re: [STDS-802-16] Broadcast

             

            Eyal,

            Seems that the standard does not preclude from
            sending data over broadcast connection. Another
            question is whether 

            we may establish a service flow associated
            with  broadcast connection. I think, we cannot,
            then there is no way 

            for data entering CS SAP to be routed to
            broadcast connection.

            By the way, multicast connections are not
            related to multicast [polling] groups.

            Vladimir
                  -----Original Message-----
                  From: Eyal Verbin
                  [mailto:everbin@AIRSPAN.COM]
                  Sent: Wednesday, April 21, 2004 1:39
                  PM
                  To: STDS-802-16@LISTSERV.IEEE.ORG
                  Subject: [STDS-802-16] Broadcast

                  Section 6.1 of the standard states
                  that " In addition to individually
                  addressed messages, messages may also
                  be sent on multicast connections
                  (control messages and video
                  distribution are examples of
                  multicast applications) as well as
                  broadcast to all stations."

                   

                  Correct me if I'm wrong, but
                  broadcast transmission is limited to
                  MAC management messages (MAPs,
                  DCD,...) and can't be used to
                  transfer data. Therefore, the only
                  way to broadcast data is to form a
                  multicast group containing all SS's


                  Eyal

                   

                   -----Original Message-----
                  From:
                  owner-stds-802-16@listserv.ieee.org
                  [mailto:owner-stds-802-16@listserv.ieee.org]On
                  Behalf Of Don Leimer
                  Sent: Monday, April 19, 2004 8:26 PM
                  To: STDS-802-16@listserv.ieee.org
                  Subject: Re: [STDS-802-16]
                  Clarification regarding SS power
                  level control

                  Only one more comment.  The final 4dB
                  of error will also be reduced by
                  subsequent BS commands, and relative
                  error diminishes to +/- 0.5dB for the
                  final error (relative to the BS's
                  capability to measure power)
                        -----Original
                        Message-----
                        From: Raja Banerjea
                        [mailto:RBanerjea@PROXIM.COM]
                        Sent: Monday, April 19,
                        2004 9:14 AM
                        To:
                        STDS-802-16@LISTSERV.IEEE.ORG
                        Subject: Re:
                        [STDS-802-16]
                        Clarification regarding
                        SS power level control

                        The power control method
                        is a closed loop method
                        where the Base station
                        asks for further power
                        control corrections if
                        required. If the base
                        station requests the
                        subscriber station in the
                        RNG-RESP to increase the
                        power level by 30dB the
                        SS should increase it by
                        30dB with a relative
                        accuracy of 4dB.

                        If the Base station is
                        going to increase the
                        power of the SS
                        in 5 steps and the
                        BS requests the SS to
                        increase the power by 8dB
                        the SS will increase it
                        by 8dB with a relative
                        accuracy of 4dB. In the
                        subsequent RNG-RESP
                        message the BS instead of
                        requesting a power
                        increase of 8dB will
                        request for 8dB+(relative
                        accuracy).
                        Therefore after each
                        increase requested from
                        the BS the relative
                        accuracy should be 4dB.

                        This assumes that the BS
                        can make an accurate
                        measurement of the SS's
                        power increase.

                        Any comments ?

                        Regards,

                        -Raja

                         
                              -----Original
                              Message-----
                              From:
                              Crozier,
                              Eugene
                              [mailto:Eugene_Crozier@SRTELECOM.COM]
                              Sent: Monday,
                              April 19,
                              2004 6:26 AM
                              To:
                              STDS-802-16@listserv.ieee.org

                              Subject: Re:
                              [STDS-802-16]
                              Clarification
                              regarding SS
                              power level
                              control

                              My
                              understanding
                              of this is
                              that the step
                              size should
                              be greater
                              than 1 dB but
                              less than 8
                              dB (I'd
                              assumed for
                              the relative
                              accuracy that
                              the 50% of
                              the step size
                              can be no
                              more than 4
                              dB), but the
                              number of
                              steps is
                              based on the
                              step size and
                              the relative
                              accuracy to
                              achieve the
                              minimum
                              control
                              range, so for
                              1 dB steps,
                              the number of
                              steps can be
                              between 60
                              and 20
                              (30/0.5 and
                              30/1.5) for a
                              30 dB range,
                              and for 8 dB
                              step size the
                              number of
                              steps between
                              8 and 3 for
                              the 30 dB
                              range.

                               

                              Regards

                               

                              Eugene
                              Crozier
                                    -----Original
                                    Message-----
                                    From:
                                    Eyal
                                    Verbin
                                    [mailto:everbin@AIRSPAN.COM]
                                    Sent:
                                    Monday,
                                    April
                                    19,
                                    2004
                                    8:22
                                    AM
                                    To:
                                    STDS-802-16@listserv.ieee.org
                                    Subject:
                                    [STDS-802-16]
                                    Clarification
                                    regarding
                                    SS
                                    power
                                    level
                                    control

                                    Power
                                    level
                                    control
                                    for
                                    the
                                    OFDM
                                    PHY
                                    is
                                    defined
                                    in
                                    section
                                    8.3.9.1:

                                    " For
                                    an
                                    SS
                                    not
                                    supporting
                                    subchannelization,
                                    the
                                    transmitter
                                    shall
                                    support
                                    a
                                    monotonic
                                    power
                                    level
                                    control
                                    of
                                    30
                                    dB
                                    minimum.
                                    For
                                    an
                                    SS
                                    supporting
                                    subchannelization,
                                    the
                                    transmitter
                                    shall
                                    support
                                    a
                                    monotonic
                                    power
                                    level
                                    control
                                    of
                                    50
                                    dB
                                    minimum.
                                    The
                                    minimum
                                    step
                                    size
                                    shall
                                    be
                                    no
                                    more
                                    than
                                    1
                                    dB.
                                    The
                                    relative
                                    accuracy
                                    of
                                    the
                                    power
                                    control
                                    mechanism
                                    is
                                    +/-50%
                                    of
                                    the
                                    step
                                    size
                                    in
                                    dB,
                                    but
                                    no
                                    more
                                    than
                                    4
                                    dB.
                                    As
                                    an
                                    example,
                                    for
                                    a
                                    step
                                    size
                                    of
                                    5
                                    dB
                                    the
                                    relative
                                    accuracy
                                    is
                                    2.5
                                    dB.
                                    For
                                    a
                                    BS,
                                    the
                                    transmitter
                                    shall
                                    support
                                    a
                                    monotonic
                                    power
                                    level
                                    control
                                    of
                                    10
                                    dB
                                    minimum." 

                                    Looking
                                    at
                                    the
                                    SS
                                    (subchannelization)
                                    for
                                    example,
                                    it
                                    is
                                    possible
                                    to
                                    go
                                    from
                                    Min
                                    power
                                    to
                                    Max
                                    power
                                    either
                                    in
                                    5
                                    steps
                                    of
                                    8
                                    dB
                                    or
                                    in
                                    a
                                    single
                                    step
                                    of
                                    50dB.
                                    In
                                    the
                                    first
                                    option
                                    the
                                    accumulated
                                    offset
                                    can
                                    reach
                                    5*4dB
                                    (20dB)
                                    wheras
                                    in
                                    the
                                    second
                                    option
                                    the
                                    tolerance
                                    is
                                    limited
                                    to
                                    4dB.

                                    Does
                                    anyone
                                    have
                                    a
                                    more
                                    clear
                                    interpretation
                                    of
                                    this
                                    text?

                                    Eyal
                                    Verbin 



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