[srslte-users] Iperf

[Fateme Rezaee]

Dear all,
I have some question about  connecting a UE and running the iperf with
different inputs.
For instance, with the following setups for the bandwidth ,(The output from
the DCI formation is sth as follows (from the function int
sched_ue::generate_format1(dl_harq_proc *h,
                         sched_interface::dl_sched_data_t *data,
                         uint32_t tti,
                         uint32_t cfi)))
1.
 iperf3 -c 192.168.3.2 -p 5202 -u -t 150 -b 0


SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=180648,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=180519,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=181070,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=181621,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=181492,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=182043,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=181914,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=180961,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=183015,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=27, tbs=3963, nof_prb=50, req_bytes=182062,
cell.nof_prb = 50

2.
 iperf3 -c 192.168.3.2 -p 5202 -u -t 150 -b 5M
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=100705,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=97166,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=24, tbs=2961, nof_prb=44, req_bytes=93628,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=90670,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=87131,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=83592,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=24, tbs=2961, nof_prb=44, req_bytes=80054,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=23, tbs=3182, nof_prb=50, req_bytes=77096,
cell.nof_prb = 50

3.
 iperf3 -c 192.168.3.2 -p 5202 -u -t 150 -b 15M

SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=104244,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=100705,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=97166,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=24, tbs=2961, nof_prb=44, req_bytes=93628,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=90670,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=87131,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=25, tbs=3542, nof_prb=50, req_bytes=83592,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=24, tbs=2961, nof_prb=44, req_bytes=80054,
cell.nof_prb = 50
SCHED: Alloc format1 new mcs=23, tbs=3182, nof_prb=50, req_bytes=77096,
cell.nof_prb = 50


1. My main question is that why the nof_prb which is the output of the
following function almost the same with the cell.nof_prb? Does it mean that
the connected UE uses all the available PRBs regardless of the iperf input?
what happened if I could connect another UE? Is it possible that the PRBs
in one tti be allocated to both of them?
 uint32_t nof_prb = format1_count_prb(h->get_rbgmask(), cell.nof_prb);

2. when for the iperf, -b is set as (5,10,15 -M), for the srslte, the rate
for the downlink is some how similar to the iperf log, but when -b is set
(20M), the rate in srslte is the same as when -b is set to 15M. however,
when -b is set 0 (unlimitted), the rate in srslte is about 30Mbs. Why this
is so?

3. When I try to connect another Ue, for the Iperf if I use the default
value for -b( it is 1Mbs), both the UEs will be connected but their rates
are low. If I change the value of -b and set it as 5M, just one UE could be
connected? why?

Thank you.
-- 
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Best regards,

Fatemeh.Rezaei

Ph.D. Student in Communication Systems Engineering

Department of Electrical and Computer Engineering, Yazd University

Yazd, Iran

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