Interference on Idle (IOI) — Планирование и оптимизация сетей GSM

[QIP]

Hi all!

i am an RF planning and Optimization engineerr at Fastlink - Jordan
I vae come a cross some Radios where i get difference IOI values per time Slots in a micro (motorola equipment)

ie
Time Slot 0|1|2|3|4|5|6|7
Radio 1 IOI 1|1|1|1|0|0|1|1
Radio 2 IOI 1|1|1|1|0|0|1|1

not exactly s and zeros but the IOI on thr 4th and 5th time slots is really minimal... as if there is no traffic on those 2 time slots on both radios..

what i cant understand is that why isntthere any traffic on those radios? they do not have high tch loss values as well!!

any idea?

[Denis Insane]

I don`t speak english
Measurement is spent when the ts is free. If the ts has been "busy" five minutes ago, then IOI is "five minutes ago" for this ts and "real-time IOI" for idle ts. And "numbers" of the ts can be such because of strategy of allocating of channels.
Radio 1 and Radio 2 - is 2 RF in 1 cell with hopping?

[QIP]

Hopping is disabled on all RTFs/Radios and both Radios are in 1/single cell!!

I know IOI is measured while in Idle mode, the values i posted where taken along 1 full day!

the thing is; both radios have very low IOI values on the same TSs (4 and 5)
all TSs have IOI values of around 5; where as those TSs IOI value is less than 1

i suspect hardware problem somehow,,, but its quite extra ordinary to have same hardware problems in 2 or more radios on the same cell! isnt?

[Nartin]

Check those TSs (if it is TCH) by locking all others TCH and performing a test call. I think that it's a software problem because all TRX must be with the same value of IOI in case of hardware error.
By the way, what logical channels are used on those TSs?

[QIP]

Its a 4-Radios Microcell

Logical configuration is:

TS4|TS5
BCCH radio TCH|GPRS switchable
TCH Radio 1 TCH|TCH
TCH Radio 2 TCH|TCH
TCH Radio 3 TCH|TCH

[barker]

I don`t know motorolla micro but I heard that at nokia BTS exists such socalled "sleepy" (or "sealed") TSs phenomenon.
Locking and unlocking radios again helps in most cases.

What about call blocking and traffic in the cell? Are they correlate with Erlang B Table?

[QIP]

Nothing, we work on 0.02 blocking rate, there is not blocking/ congestion on the site.

yesterday after a reset to the Micro the low IOI values switched to TSs 6 and 7.

[barker]

Strange.
Do you exactly know that threre are no traffic at those TSLs?

I think it`s a good idea to lock all TSLs independently except "strange" one and see the TCH occupance, isn`t it?

[Waveman]

You have no IOI measuremnts on TS4,5 because, may be, they are configured as ЗВЕСР (GPRS switchable or reserved). On PDTCH channels IOI doesn't measures. After reset, PDTCH moves on TS6, 7 thats why you have zero IOI on this Timeslots . Best regards!

[QIP]

I already mentioned in my 3rd reply above that those time slots were configured as TCH channels only - no GPRS reserved nor switchable.

those 2 radios had a power amplifier alarm after a week, and were replaced with new ones, not sure if it that no ioi was a side effect or something,