Decrease CSFB Delay

[mounir34]

dears
please any sugestions to decrease CSFB delay ,

BR
Thanks

[thuti]

dears
please any sugestions to decrease CSFB delay ,

BR
Thanks

Do you mean about "call setup time" in LTE?

[mounir34]

check the below call signaling the delay is high

Extended service request ==> 4G_RRCConnectionRelease	205 ms
4G_RRCConnectionRelease ==> 3G_RRCConnectionRequest	159 ms
RRC Connection Request ==> Call Proceding	1.636 s
Call Proceding ==> RRC Connection Release Complete	600s

Do you mean about "call setup time" in LTE?

[babak1349]

dears
please any sugestions to decrease CSFB delay ,

BR
Thanks

hello
the CS fall back is like as re-selection to another technology and it seems the user re-establish the call in another technology So you have 2 main part
1) reselectiong to another technology and camping on a new cell
2) normal call setup procedure (so you need to check the target technology to see how it is the call setup time over it)

to accelerate the reselection to another technology you might consider to activate RIM ( I think it supported on Release 9 UE's onward)
you might consider to activate measurement-based CSFB instead of blind release and redirect
and also you might consider PSHO-based CSFB
cheers

[mounir34]

thnaks freind for your feedback ,
for flash CSFB based on RIM procedure already activated , the High delay is noticed in 3G part after fall back from LTE ,if you have any switches or parameter highly recommended ,
for PS HO is not recommended because not all users can support the HO based especaily Qualcom chipset also the probability of failure will increase compared by Redirection ,

thanks

hello
the CS fall back is like as re-selection to another technology and it seems the user re-establish the call in another technology So you have 2 main part
1) reselectiong to another technology and camping on a new cell
2) normal call setup procedure (so you need to check the target technology to see how it is the call setup time over it)

to accelerate the reselection to another technology you might consider to activate RIM ( I think it supported on Release 9 UE's onward)
you might consider to activate measurement-based CSFB instead of blind release and redirect
and also you might consider PSHO-based CSFB
cheers

[babak1349]

thnaks freind for your feedback ,
for flash CSFB based on RIM procedure already activated , the High delay is noticed in 3G part after fall back from LTE ,if you have any switches or parameter highly recommended ,
for PS HO is not recommended because not all users can support the HO based especaily Qualcom chipset also the probability of failure will increase compared by Redirection ,

thanks

hello
are you sure about RIM capability and functionality works properly ? the target RAT should be RIM capable and you should have external cell and cell relation defined in enodeB (check rrc connection release message in TEMS to see if the system sends of SyS info of target cells of target RAT)
something else how long takes time to setup a call during CSFB and compare it with a call setup of a user who camped already in 3G ? compare the message flow and their timing (use TEMS)
It could be due time that user spends to camp on target cell so you may manipulate
the RACH related parameters in 3G

cheers

[mounir34]

yes Flash CSFB is working properly

below is the delay for each phase ,

Extended service request ==> 4G_RRCConnectionRelease 205 ms
4G_RRCConnectionRelease ==> 3G_RRCConnectionRequest 159 ms
RRC Connection Request ==> Call Proceding 1.636 s
Call Proceding ==> RRC Connection Release Complete 600s

hello
are you sure about RIM capability and functionality works properly ? the target RAT should be RIM capable and you should have external cell and cell relation defined in enodeB (check rrc connection release message in TEMS to see if the system sends of SyS info of target cells of target RAT)
something else how long takes time to setup a call during CSFB and compare it with a call setup of a user who camped already in 3G ? compare the message flow and their timing (use TEMS)
It could be due time that user spends to camp on target cell so you may manipulate
the RACH related parameters in 3G

cheers

[babak1349]

yes Flash CSFB is working properly

below is the delay for each phase ,

Extended service request ==> 4G_RRCConnectionRelease 205 ms
4G_RRCConnectionRelease ==> 3G_RRCConnectionRequest 159 ms
RRC Connection Request ==> Call Proceding 1.636 s
Call Proceding ==> RRC Connection Release Complete 600s

so the problem is not the cell change from LTE to 3G as you can see it is just 159 ms to send RRC connection request on 3G. it means you don't have radio issue ?
so do you see Alerting on NAS message on 3G ?
why you didn't mention RRC connection setup complete time ?
do you see call setup complete time in TEMS

do you receive RRC connection release during call set up procedure in 3G ???

cheers

[babak1349]

so the problem is not the cell change from LTE to 3G as you can see it is just 159 ms to send RRC connection request on 3G. it means you don't have radio issue ?
so do you see Alerting on NAS message on 3G ?
why you didn't mention RRC connection setup complete time ?
do you see call setup complete time in TEMS

do you receive RRC connection release during call set up procedure in 3G ???

cheers

after call proceeding , RAB assignment and radio bearer setup happens and then alerting (NAS)
and then connect (NAS) so do you see those messages ?

I don't think you have radio issue CSFB is around 159 ms

you may have problem in NAS messages which is core related but you need make sure about the message flows which you see

if call setup is around 2 sec it is good really


cheers

[mounir34]

no Alerting because during the test we called the Operator server that why
if we call normal number the Delay will be much higher

after call proceeding , RAB assignment and radio bearer setup happens and then alerting (NAS)
and then connect (NAS) so do you see those messages ?

I don't think you have radio issue CSFB is around 159 ms

you may have problem in NAS messages which is core related but you need make sure about the message flows which you see

if call setup is around 2 sec it is good really


cheers