Re: stds-80220-requirements: System Gain Requirement, 4.1.1

["Marc Goldburg" <marcg@arraycomm.com>]

Folks,

As has been pointed out, a numerical value for tolerable path loss
presupposes 

  - PA sizes and antenna gains which are product issues rather than
    protocol issues

  - receiver sensitivity which is defined elsewhere in the document

  - PERs and FERs which are addressed elsewhere in the document

  - acceptable values for latency (related to packet length), Rayleigh and
    shadowing outages which are scenario parameters to be addressed in the
    evaluation document.

I would argue first for removing section 4.1.1 in its entirety.  Failing
that, I support Reza's approach but would generalize it to handle the MIMO,
SIMO and MISO cases as follows, as well as allowing the definition to
address uplink performance.

  The 802.20 air interface specification is required to provide appropriate
  means to enable future implementations of 802.20 to maximize their system
  gain as defined below. This can be achieved through a combination of
  techniques including improved receiver performance for specific
  modulation schemes at specified bit error probability. It is expected
  that numerical values for system gain and related parameters be provided
  in the air interface evaluation criteria process.

  The "system gain" is defined as the difference, in dB, between the
  transmitter power output and the receiver threshold (sensitivity) for a
  given data rate and frame error rate.  Only that portion of the
  transmitter power intended for the designated receiver is included in the
  system gain calculation.  In the case of MIMO, MISO or SIMO systems,
  transmitter power is calculated as the incoherent sum of powers at the
  output of each power amplifier, and receiver threshold is calculated as
  the incoherent sum of powers at the input of each receiver chain
  corresponding to the target BER or FER following multichannel processing.

Regards,

Marc