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      ATM Forum Document Number: ATM Forum/96-1268

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      Title: MIMO Frame Latency Metric - Revised Definition

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      Abstract:

      MIMO  latency  is  extended to cover the case of discontinguous input
      frames.


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      Source:

      Raj Jain, Gojko Babic
      The Ohio State University
      Department of CIS
      Columbus, OH 43210
      Phone: 614-292-3989, Fax: 614-292-2911, Email: Jain@cse.wustl.edu

      The presentation of this contribution at ATM Forum is sponsored by NASA.

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      Date: October 1996

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      Distribution: ATM Forum Technical Working Group Members (TM, TEST)

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      Notice: This contribution has been prepared to assist the ATM  Forum.
      It  is  offered  to  the Forum as a basis for discussion and is not a
      binding  proposal  on  the  part   of   any   of   the   contributing
      organizations.   The  statements  are  subject  to change in form and
      content after further study.  Specifically, the contributors  reserve
      the right to add to, amend or modify the statements contained herein.

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      The MIMO latency as currently defined in the baseline document is:

      MIMO = Min{LILO, FILO - NFOT}

      Where:
      LILO = Last-bit in to last-bit out time for the frame
      FILO = First-bit in to the last-bit out time
      NFOT = Normalized frame output time = Frame size/output link rate

      This definition assumes that the input to the network is  contiguous.

      In  the  last  ATM  Forum  meeting,  the issue of discontiguous input
      frames was brought up. To handle this case, NFOT needs to be  defined
      as follows:

      NFOT  =  Normalized  Frame  Output Time = FILI*Input Link Rate/Output
      Link Rate

      Where,
      FILI = First-bit in to last-bit in time (includes all gaps)

      This  modified  definition  works  for  contiguous  and  discontigous
      inputs.  In  particular,  note that if the input frame is contiguous,
      FILI*Input Link Rate is equal to  frame  size  and  so  the  previous
      definition is a special case of this more general definition.

      A list of all possible cases and how this modified definition handles
      them will be presented at the forum.