Further Reading - Specs to Refer

Which spec to refer and for what?

Further reading

• TR 36.806 Evolved Universal Terrestrial Radio Access (E-UTRA); Relay architectures for E-UTRA (LTE-Advanced)
• TR 36.808 Evolved Universal Terrestrial Radio Access (E-UTRA); Carrier Aggregation; Base Station (BS) radio transmission and reception
• TR 36.814 Evolved Universal Terrestrial Radio Access (E-UTRA); Further advancements for E-UTRA physical layer aspects
• TR 36.815 Further Advancements for E-UTRA; LTE-Advanced feasibility studies in RAN WG4
• TR 36.817 Evolved Universal Terrestrial Radio Access (E-UTRA); Uplink multiple antenna transmission; Base Station (BS) radio transmission and reception
• TR 36.819 Coordinated multi-point operation for LTE physical layer aspects
• TR 36.823 Evolved Universal Terrestrial Radio Access (E-UTRA); Carrier Aggregation Enhancements; UE and BS radio transmission and reception
• TR 36.826 Evolved Universal Terrestrial Radio Access (E-UTRA); Relay radio transmission and reception
• TR 36.871 Evolved Universal Terrestrial Radio Access (E-UTRA); Downlink Multiple Input Multiple Output (MIMO) enhancement for LTE-Advanced
• TR 36.912 Feasibility study for Further Advancements for E-UTRA (LTE-Advanced)
• TR 36.913 Requirements for further advancements for Evolved Universal Terrestrial Radio Access (E-UTRA) (LTE-Advanced)
• TS 36.101 Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio transmission and reception
• TS 36.211 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation
• TS 36.212 Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding
• TS 36.213 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures
• TS 36.216 Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer for relaying operation
• TS 36.221 Evolved Universal Terrestrial Radio Access (E-UTRA); Medium Access Control (MAC) protocol specification
• TS 36.300 Evolved Universal Terrestrial Radio Access (E-UTRA) and Evolved Universal Terrestrial Radio Access Network (E-UTRAN); Overall description; Stage 2
• TS 36.306 Evolved Universal Terrestrial Radio Access (E-UTRA); User Equipment (UE) radio access capabilities
• TS 36.331 Evolved Universal Terrestrial Radio Access (E-UTRA); Radio resource Control (RRC) protocol specification

NAS Procedure

1. NAS Prcodeure?
A. According 24.301 (NAS) There are two types of procedure which can be seen on NAS layer.

      EMM (EPS Mobility Management) Procedure.     Three types of ESM procedures can be distinguished.

1.  EMM common procedures:
    An EMM common procedure can always be initiated whilst a NAS signalling connection exists.
   
   The procedures belonging to this type are:
                             Initiated by the NW: -
                                          GUTI reallocation; -
                                          Authentication; -
                                          Security mode control; -
                                          Identification; -
                                          EMM information. 
2. EMM specific procedures:
   At any time only one UE initiated EMM specific procedure can be running.
   The procedures belonging to this type are:
                             Initiated by the UE:
                                           Attach: -
                                           Detach:-
                                           Tracking Area Update:-
                                                        Normal and periodic tracking area updating procedure
                                                        Combined tracking area updating procedure
                             Initiated by the NW:
                                           Detach:- 
3. EMM connection management procedures (S1 mode only):
                             Initiated by the UE: -
                                          Service request
                             Initiated by the UE/NW: -
                                          Transport of NAS Messages
                                          Generic transport of NAS messages procedure
   
                               Note:  Not sure why two different kind of transport of NAS messages?
                                          Need to check in detail about their work and differences and need.
   
                             Initiated by the NW: -
                                          Paging Procedure              
   

MAC Procedure

1. What are all the procedure in MAC?
A. According 36.321 (MAC) below are the procedure which belongs to MAC.

1. 5.1 Random Access procedure
1. 5.1.1 Random Access Procedure initialization
2. 5.1.2 Random Access Resource selection 
3. 5.1.3 Random Access Preamble transmission
4. 5.1.4 Random Access Response reception 
5. 5.1.5 Contention Resolution 
6. 5.1.6 Completion of the Random Access procedure  
2. 5.2 Maintenance of Uplink Time Alignment 
3. 5.3 DL-SCH data transfer 
1. 5.3.1 DL Assignment reception
2. 5.3.2 HARQ operation 
3. 5.3.3 Disassembly and demultiplexing  
4. 5.4 UL-SCH data transfer 
1. 5.4.1 UL Grant reception
2. 5.4.2 HARQ operation
3. 5.4.3 Multiplexing and assembly 
4. 5.4.4 Scheduling Request 
5. 5.4.5 Buffer Status Reporting 
6. 5.4.6 Power Headroom Reporting 
5. 5.5 PCH reception 
6. 5.6 BCH reception 
7. 5.7 Discontinuous Reception (DRX) 
8. 5.8 MAC reconfiguration 
9. 5.9 MAC Reset 
10. 5.10 Semi-Persistent Scheduling 
1. 5.10.1 Downlink
2. 5.10.2 Uplink  
11. 5.11 Handling of unknown, unforeseen and erroneous protocol data             

RACH Procedure in LTE

1. What is full form of RACH?
A. Random access Channel Request.

2. What are the types of RACH?
A. Contention based and Non Contention based.

3. Where to use contention based and where to use non contention based RACH?
A.
Non Contention based:
                                     During handover non contention based RACH to be used as HO is time                                                intolerant and if contention based RACH used then call drop might be                                                    observed.
Contention based:
                                     All Other time contention based RACH can be used.

4. Why do we need RACH?
A. Whenever UE want's to establish a RRC Connection , it needs to perform the RACH procedure.
     This procedure helps UE to get synced with the NW and perform the desired action over the                established RRC Connection.

5. When do we need RACH?  
A. According Spec:

• Initial Access - UE is trying to access the network in RRC idle state.
• During RRC connection re-establishment procedure .
• Handover
• When uplink synchronization is lost :- It means from a certain duration network has not received anything from UE in uplink.
• When UE does not have any PUCCH resources available for SR(Scheduling Request) .
• When timing advance is needed for positioning purpose in RRC connected state for UE.

6. Steps for Random Access Procedure?
A. From 3GPP TS 36.321(MAC) Segment 5.1

1. 5.1.1 Random Access Procedure initialization
2. 5.1.2 Random Access Resource selection 
3. 5.1.3 Random Access Preamble transmission
4. 5.1.4 Random Access Response reception 
5. 5.1.5 Contention Resolution 
6. 5.1.6 Completion of the Random Access procedure  

Reference:

3GPP TS 36.300 segment10.1.5.1

3GPP TS 36.331(RRC) segment 5.3.3.3

3GPP TS 36.321(MAC) segment 5.1.5