stds-802-16-tg3: Summary of RSSI/CCI Conf Call 10 Oct 2001
A brief summary of 10 October 2001 RSSI and CCI Conference Call.
A number of MAC layer messages exist which can be used to initiate requests
and make responses for RSSI and CCI measurements. Some of these messages
are in the TG1 spec
(as pointed out by Yigal); other messages are proposed in the TG3/4 Air
Interface Standard. The MAC delivery mechanism for RSSI/CCI will be sorted
out in the TG3/4 MAC meetings, and though important, was not the focus of
these PHY layer discussions.
Anader Benyamin-Seeyar pointed out, the ETSI BRAN has dealt extensively
with the issue of RSSI and CCI measurement. There are also some
algorithmic procedures identified for RSSI and CCI measurements in the in
the TG1 document (see Para 18.104.22.168.1.2). Walt Roehr also mentioned that
the TDMA standard ( IS 54/136 ?) deals extensively with the issue of RSSI
measurement over a number of channels and that there may be useful
information in this standard applicable to our own.. Please call these
gentlemen if you want more details.
The CC resolved that the RSSI measurement should be a long term mean that
is determined from multiple measurements done on the downlink broadcast
frames, as they will be set at maximum EIRP. The subscriber terminal will
be responsible for taking such a measurement and estimating a dBm value of
received channel power. Additionally, a measurement of the variance on the
estimate will be undertaken. Issues such as the averaging interval,
resolution bandwidth used, and other technical issues dealing with sampling
are left to the commentators to propose and discuss. It has also been
suggested that there be a MAC layer instruction which would cause the PHY
layer to restart a calculation of the long term mean RSSI.
For CCI is was felt that the best estimator of co-channel interference
would be a measurement of the Bit Error Rate (prior to the decoders) and/or
calculation of the Mean Square Error. This (these) measurement, along with
the RSSI value, would allow the terminal to determine the co-channel +
thermal noise interference level on the channel. These measurements are to
be carried out in the subscriber terminal. CCI would be sent as a dBm
received channel power level value. Also, it was decided that
the variance of the mean CCI estimate be calculated and sent.
It is now left to the commentators to propose how to best execute the
measurements within the OFDM., OFDMA, and SC schemes.. Submission are due
on the 19 th of October. 2001. We will discuss the comments in Austin.
I will endeavor to find out exactly what section of the proposed PHY
standard document these comments should be directed toward, and will pass
this information to you ASAP.
Thanks to all for participating. Thanks to Durga Satapathy and Sprint for
hosting the CC
Research Broad Band Wireless
Communications Research Centre
3701 Carling Avenue