LTE Training

3G Network Solutions

LTE/IMS/IoT/5G Telecom Centre

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LIVE Projects on TEMS tools

1. Conformance Test for all Protocol Stack Modules
2. Field Test and trial of Handphone Modules or eNB Modules
3. Analysis of Calls at Message Levels, IE Levels and Bit/Bytes Level
4. Optimization of Network Throughput with RRC/PHY Layer Parameters tuning
5. Intra and Inter-RAT verification etc..
6. Comparisons of Dongle/UE performance and reporting areas of improvements

Conformance Testing (36.523)

Conformance Testing with respect to:
1.36.304
2.36.331
3.36.321
4.36.322
5.36.323
6.24.301
And End-to-End Call processing tests.

Project Development&Testing- Hands-ON

Course attendees participate in one or more of the following projects with C/Linux and LTE Protocol Stack development. Testing is done for these software  with respect to 3GPP based unit test and conformance test.

eNB-RRC Design (36.331,36.304)
RRC implementation is to design a simplified RRC with UE-RRC communicating with eNB RRC. The L2 and L1 is bypassed by direct L3-L3 messaging. NAS is also simplified to make the L3-RRC running. eNB-RRC design is simplified by implementing limited functionalities. Interprocess communication is achieved by MessageQueues. Here are the Functions, Process and Messages.

Processes: 

Main-Init 
     UE Contexts,
     L1-L2Config
     RAB Manager
     RadioRes
SI Broadcast
Paging Handler
RRC_Msg
Call_Proc 

S1-AP Handler
Uu-AP Handler

Messages Received
NASPaging

    RRCConnectionRequest
    RRCConnectionSetupComplete
    ... Other messages later...
Messages Sent: 
    MIB

    SIB1
    SchedulingInfo
    RRCPaging
    RRCConnectionSetup
    RRCRelease
    ... Other messages later...

Implementation of eNB-RRC

Initial implementation will be achieved by the following Process sequence:

Main_Init -
This is the first task and it will launch (fork) other main tasks - SI broadcast, Paging & RRC_Msg. Holding all database, ready to supply any data to any process by IPC. The very frequently required data by many processes will be implemented by SharedMemory. Also fork 3 communication Processes (S1-AP, Uu-AP and X2-AP). 


SI Broadcast – Read the SI default database from File. Initialise all the structures. Send MIB and SIB1 in appropriate times. Connect this process with MAC simulator. Send MIB and SIB1. Form all the other SIBs(SIB2 to SIB13) periodicity and window. Design the timings in such a way that they do not overlap and no clash and define the respective SchedulingInformations(SI). For verification, print the Frame/Subframe numbers and the SI/SIBs being transmitted.

Paging Handler
– Receive the NAS Paging from RRC_Msg_Handler or directly from S1-AP. Calculate the Paging Frame and Paging Occasions for all types of UE-Ids. Buffer the incoming Pagings until the respective UE-Ids PO comes. Connect this process with MAC simulator. Compile the paging records of same PO into one buffer and send them to MAC for transmission.


RRC_Msg – This process will receive the messages from S1-AP and Uu-AP both. Some messages may be simply forwarded to the destination, marked by Protocol discriminator. If the messages is for itself, then call the respective function or pass it on to the respective process. If there is no entry for this message in context table, make entry and process when RRC-Connected.
 
S1-AP(Tx/Rx)
– It will receive messages from NAS as well as RRC. Ignore the lower layer software now and simply forward to the destination.


Uu-AP(Tx-Rx)
– It will receive messages from RRC, SI Broadcast, Paging as well as PDCP. Ignore the lower layer software now and simply forward to the destination.

 Figure 1.1 – High level Inter Process Communication among eNB-RRC Modules.



 

UE-RRC Design (36.331, 36.304)

Process: The limited processes are implemented to keep the design simple. The main processes are
Main_Init
                     i.    default Config,
                     ii.    Timers& Constants,
                    iii.    RAB-Resource Mapping
                    iv.    CSG List
                     v.    Own Context,
       RRC Msg Proc,
       SI Reception
       IdleModeTask
      Paging Handler
      Measurement

Message send:
      RRC Connection Request
      RRC ConnectionSetupComplete,
Message Receive:
    Paging Receive,
    RRC Connection Setup
    RRC Release Receive,
    Receive MIB,
    Receive SIB1 &
    Receive SI.

Implementation of UE-RRC
Initial implementation will be achieved by the following Process sequence:

Main_Init Proc - Holding all database, ready to supply any data to any process by IPC. The very frequently required data by many processes will be implemented by SharedMemory. From Main_Init, fork RRC_Msg_Proc, SI_Receive, IdleModeTask, Paging and Measurement.
SI Reception – Read MIB and SIB1 in appropriate times. According to the SI in SIB1, all the other SIBs(SIB2 to SIB13) are received as per their periodicity and window. determine the timings of each SIB. For verification, print the Frame/Subframe numbers and the SI/SIBs being received.
IdleModeTask- PLMN selection, Cell selection and Re-Selection are part of this task. This will check barred/reserved status of cell and avoid entering barred cells. If not barred then evaluate S & R criteria, speed factors, CSG membership and determine ranking to move to the best cell. Tracking Area Update and Paging are handled by another Process.
Paging Handler – Receive Paging from Physical layer in its PF and PO timings. Inform NAS and let NAS activate the receive of the call through RRC_Msg_Proc

Measurement
- UE continuously measures signal level RSRP and RSRQ for its own and rest of the Neighbouring cells. Report these if required or log them.

Figure 1.2 – High level Inter Process Communication among UE-RRC Modules.