Question: Cell utilization is low but I am still getting more half rate traffic.

[janpamp]

Hi Experts,

How do you increase Full rate traffic in a lowly utilized cell? and why is this happening?
Traffic channel should always be on full rate since I have low utilization right?

Thank you

[SHIVAM]

Hi,

I believe you need to check the Thresholds for Triggering Call from Full Rate to Half Rate & vice versa. In Nokia, they are known by name "FRL-FRU, AFRL-AFRU".

[janpamp]

I already adjusted the FRL-FRU to 26-28.. Still FR penetration is low. Any other suggestions to increase FR traffic?

[linhhy]

Check initial HR threshold please.

[janpamp]

Check initial HR threshold please.

where can i get that initial HR threshold? what is its equivalent parameter in nok

[linhhy]

What's your vendor equipment.

[janpamp]

What's your vendor equipment.

nokia is the equipment sir

[SHIVAM]

Hi Janpamp,

Please share the number of TRX available and HR/FR percentage in 1 sample cell. Also, the type of TCH configured:- TCHF/TCHD or TCHH

Since your cell is less utilized, can you try to disable the Packing/Unpacking by keeping FRL>FRU in the sample cell and see any change.

[linhhy]

nokia is the equipment sir

Based on your configuration, you can set difference threshold to trigger HR channel. Normally HR can be allocated when #FR channel < 4 with cell 2 TRXs, and #FR channel < 6 with cell 4 TRXs. Try it first, see the result, after that you can optimize packing and unpacking HR channel.

HR is controlled by two parameters that determine the values of the upper and the lower limit for FR TCH load in a cell. The limit parameters are given as relative amounts of free FR TCH resources in proportion to working FR TCH resources. The parameters can be defined on both the BSC level and the SEG level.

lower limit for FR TCH resources

BSC level: lower limit for FR TCH resources (HRL)

SEG level: lower limit for FR TCH resources (FRL)

The parameter gives the lower limit percentage value of the relative amount of free FR TCH resources. The limit includes permanent and DR types together. If a FR TCH was chosen the previous time the rate determination dependent on cell load was applied, the relative amount of free FR TCH resources must be above this limit for a FR TCH to be allocated. If the relative amount of free FR TCH resources is below the lower limit, a HR TCH has to be allocated.

upper limit for FR TCH resources

BSC level: upper limit for FR TCH resources (HRU)

SEG level: upper limit for FR TCH resources (FRU)

The parameter gives the upper limit percentage value of the relative amount of free FR TCH resources. If a HR TCH was chosen the previous time the rate determination dependent on cell load was applied, the relative amount of free FR TCH resources must be below this limit for a HR TCH to be allocated. If the relative amount of free FR TCH resources is above the upper limit, a FR TCH has to be allocated.

[janpamp]

Hi Janpamp,

Please share the number of TRX available and HR/FR percentage in 1 sample cell. Also, the type of TCH configured:- TCHF/TCHD or TCHH

Since your cell is less utilized, can you try to disable the Packing/Unpacking by keeping FRL>FRU in the sample cell and see any change.

All in busy hour (6pm-10pm)
HR traffic: 89.99
FR traffic: 12.17
TRX: 4
GTRX: 2
Channel config: All in TCHD
FRL: 20
FRU: 25
AFRL: 20
AFRU: 25

What would you recommend values for FRL/FRU to disable unpacking?

[linhhy]

It's better if you provide information only on busy hour.

[janpamp]

It's better if you provide information only on busy hour.

Its the busy hour already

[linhhy]

Its the busy hour already

You mean 90 Erl with 4 TRX on peak hour? --> It cant happen.
4 TRx with 100%HR ~60 TCH HR --> cant carries more than 50 Erl with Gos 2%.

[linhhy]

There are some features to help us understanding when HR channel is allocated and how optimize it.

[janpamp]

You mean 90 Erl with 4 TRX on peak hour? --> It cant happen.
4 TRx with 100%HR ~60 TCH HR --> cant carries more than 50 Erl with Gos 2%.


Apologies it is 8 TRX

[janpamp]

There are some features to help us understanding when HR channel is allocated and how optimize it.
kindly email at janpamp@yahoo.com i cant download it sir.

[linhhy]

Apologies it is 8 TRX

Let calculate with 8 TRX:
Total Timeslot: = 8 x8 =64 TS.
1 BCCH
6 SDCCH
4 Dedicated PDCH (assumption)
--> # Timeslot TCH FR (voice) = 64-1-6-4=53 TS.
~ 53x2=106 HR channel.
With 106 HR channel (maximum), you carries ~ 100 Erlang (90HR+10FR), it's very high utilization of course.

[linhhy]

kindly email at janpamp@yahoo.com i cant download it sir.
Share some your good documents and try to give some useful information. It's not much difficult to get permission download.