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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 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

John Sydor
Research Broad Band Wireless
Communications Research Centre
3701 Carling Avenue
Ottawa, Canada
K2H 8S2
Ph. 613-998-2388