[Miguel Monteiro]

Hello all,

I am trying to implement intra-LTE handover in the simulator.
I want to implement it based on RSRP measures and use hysteresis, time to trigger and cell specific offsets. However, I first need to get measurements from all the eNodeBs for each UE.
I noticed that the function link_quality_model allows to measure the SNR and SINR for the eNodeB the UE is connected to.
Is there any way to measure the signal from all the neighbouring eNodeBs for a given UE?

Best Regards,

Miguel

[chuan ma]

Hello Miguel,

I’m also working on the topic of handover now.

You mentioned the function link_quality_model, but I can’t find this function. Could you please tell me where the function is? I’m using LTE_System_Level_1.6_r885_light. Do you use this version or a newer one?

Best Regards,

chuan

[Martin Taranetz]

Dear Miguel and Chuan,

the received signal from all eNodeBs, including the desired one, is calculated by calling the routine obj.get_signal_macroscale_losses, which is performed right at the beginning of the link quality model.

Best regards,
Martin.

[Manikantan Srinivasan]

Dear Martin

Greetings… Looking at this discussion, i have a doubt.

Does the LTE Downlink system level simulator support handovers (in the current releases 1.8r1375+)?

If not, if we simulate with Users being mobile, does it mean the users are always served by their first associated BS (eNodeB) during the entire simulation time?

Best Regards
Manikantan

[Martin Taranetz]

Dear Manikatan,

indeed the simulator supports handover. You can find it in the LTE_sim_main.
Please be aware that specifying a velocity does not mean that the user phyiscally moves over the map. It just serves as an input parameter for the channel model. If you physically move the user, then the simulator checks whether it has moved into an association region of a neighboring eNodeB.

Best regards,
Martin.

[Manikantan Srinivasan]

Dear Martin,

Greetings and thank you for the reply. I am working with the simulator and attempting to understand the simulator better now.
I walked through the code, and currently attempting to understand the mobility support, and in that process came across the handover code.

The code in LTE_sim_main says, “now implements a very simple handover procedure”… I understand this as, the support is related to the data transmission and does not initiate any control signaling etc., Am i right?

I have few questions related to mobility, i will open a new post.

Kind regards
Manikantan

[Yeon Tan]

Dear Martin,

Sorry to interrupt, I just want to ask, does uplink simulator (v1.5) support handover ?

Best regards,
Yeon Tan

[Martin Taranetz]

Dear Manikantan, exactly, the handover is just related to data transmissions. We do not consider any signaling.
Dear Yeon Tan, as far as I know, it does not.

Best regards,
Martin.

[Yeon Tan]

Dear Martin,

Ok, noted. Thanks very much for your reply.

Best regards,
Yeon Tan

[raheleh]

Dear Martin
you say: “the received signal from all eNodeBs, including the desired one, is calculated by calling the routine obj.get_signal_macroscale_losses, which is performed right at the beginning of the link quality model”
but i can’t find “obj.get_signal_macroscale_losses” in link_quality_model of UE.m and nowhere else.I have the same problemو
Would you assist me please?

[Martin Taranetz]

Hi,

the function get_signal_macroscale_losses is also implemented in +network_elements/UE.m.
In my version, it starts at line 284.

Best regards,
Martin.

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