Showing posts with label LTE. Show all posts
Showing posts with label LTE. Show all posts
LTE, LTE ARCHITECTURE
Joni Tyagi
1:05 PM
LTE (LONG TERM EVOLUTION) ARCHITECTURE
HISTORY
|
- Two Systems that impacted almost every Human Life
- (i) Mobile Communication Via 2G Networks.
- (ii) Wired & Wireless Data Connectivity via xDSL & WLAN 802.11 a/b/g standards.
- 3G Networks is the first major step towards the convergence of both these technologies
THE WAY TO LTE-3G
LIMITATIONS
•
The
‘Maximum Bit Rates’ are still in the range of
20mbps
•
This is way behind the other popular wireless
technologies like
•
WiFi:
802.11 a/b/g/n
•
WiMax:
802.16 e/m
•
The ‘Latency’ of User Plane Traffic (UMTS
> 30ms) and Resource
• Management Procedures (UMTS > 100ms) is
still too high
•
The
‘Terminal Complexity’ of WCDMA systems is quite high, and resulting
(i)
Expensive Equipment
(ii)
Poor Performance
LTE GOALS
•
The
‘Terminal Complexity’ of WCDMA systems is quite high, and resulting
•
It shall
Compete especially with 802.16e/m in data rates
•
It must
retain the high mobility features of GSM/UMTS
LTE
SAE DIAGRAM AND FEATURES
LTE SAE DIAGRAM
LTE FEATURES:
·
Simplify the RAN: Reduced the number of RAN
Nodes and Interfaces.
·
Reduce Latency.
·
Increase Throughput and Improve Spectrum
Efficiency.
·
Flexibility in using Frequency Bands.
·
Migrate to Optimized PS Domain with no CS
Domain.
·
Flat Architecture: Minimize the risk of
single point of failures in the network.
·
Efficient Inter-working between 3G and Non-3G
specified systems.
·
Improve Terminal Power Efficiency.
·
All IP Transport Network.
WIRELESS
TECHNOLOGY COMPARISON
LTE
/SAE INTERFACE ARCHITECTURE
NETWORK
ELEMENT FUNCTIONS
eNODE B Functons:
·
Only Network Element in EUTRAN.
·
eNB Can Handle Several Cells.
·
Radio Admission Control & Radio Resource
Management(RRM) Dynamic Resource Allocation(Scheduler).
·
Radio Bearer Mgmt: Setup, Modification and
Release.
·
UE Connection State Management and UE-MME
Connection MME Selection at the Attach of the UE.
·
Measurements Collection and Evaluation.
·
Handover Decisions and Triggering. eNB-eNB
Connections to Handle HO Ciphering and Integrity Protection.
·
IP Header Compression and Decompression User
Data Routing between UE and SAE-GW System Information Broadcasting.
·
Transmission of Paging Messages to UEs.
MME Functons:
·
Pure Signalling Entity in EPC. Contains VLR
Functionality with-in!
·
Subscriber Attach/Detach: Non-Access Signalling
(NAS).
·
Idle State Mobility Handling: Tracking Area
Updates.
·
MME-MME Connections to Handle Handovers &
TAUs.
·
Signalling Co-Ordination For SAE Bearer Setup
& Modification & Release.
·
Security (Authentication, Ciphering,
Integrity Protection.
·
Trigger and Distribution of Paging Messages
to Enb.
·
Roaming Control with the Connection to HSS.
·
A UE can use the Services of only one MME At
Any Given Time!
HSS Functons:
·
Permanent and Central subscriber Database.
·
Stores
Mobility and Service Data For Each Subscriber.
·
Contains Authentication Centre Functionality
also.
EIR Functons:
·
IMEI Validation.
·
MME Interacts with EIR to Validate the IMEI
of a UE.
·
Maintains White, Grey, and Black Lists of
IMEIs.
PCRF Functons:
·
QoS Handling Function
·
QoS Policy Negotiation with PDN
·
Validates the QoS of EPS Bearers Requested by
EPC As well
·
Charging Policy: Determines how the Packets
should be Accounted
·
PCRF to Provide Policy and Charging Rules
Every time a Bearer is Se!
SGW Functons:
·
Packet Data Anchoring Function With in EPC.
·
Receives UL Data From eNB/SGSN and Transmits
to PGW.
·
Receives DL Data From PGW and Transmits to
eNB/SGSN.
·
local Mobility Anchor point for inter-eNodeB
handover.
·
Mobility anchoring for inter-3GPP mobility.
·
“End Marker" Notification to Source eNB
or SGSN after Path Switch.
·
Downlink Packet Buffering and Initiation of
Network Triggered Service.
·
Packet Marking W.R.T QOS Implementation
Required for a EPS Bearer.
·
Bearer Binding Functions.
·
A UE can use the Services of only one SGW At
Any Given Time!
PGW Functons:
·
Packet Data Anchoring Function With in EPC
·
Receives UL Data From SGW And Transmits to
PDN
·
Receives DL Data From PDN and Transmits to
SGW
·
Mobility Anchor point for Non-3GPP Mobility
·
DHCP Function: IP Address Allocation TO UE
·
Deal with PCRF for Finalizing PCC Rule for a
EPS Bearer
·
Packet Marking W.R.T QOS Implementation
Required for a EPS Bearer
·
Policy and Charging Enforcement Function
[PCEF]: Billing Generation
·
Bearer Binding Functions
·
UE Can use Services of Many PDN GWs to
Connect to Multiple PDNs
LTE, UE Power ON
Q01. In power on which Layer activate 1st ?
Joni Tyagi
1:16 PM
Q01. In power on which Layer activate 1st ?
Q02. What is the 1st job RRC Layer performed during power on procedure?
Q03. How Physical Layer Scan all Frequencies and pick-up 1 frequency?
Q04. How UE select a Frequency?
Q05. What is cell selection and re-selection procedure in lte?
Q06. How UE guess middle DC frequency of a Bandwidth?
Q07. How NAS layer select PLMN if no’s of PLMN information provided by RRC Layer?
Q08. What is PSS, which sequence is using in PSS?
Q09. What kind of information PSS Carry?
Q10. What is the location of PSS in Type-1 Frame structure?
Q11. What is the location of PSS in Type-2 Frame structure?
Q12. What is SSS, which sequence is using in SSS?
Q13. What kind of information SSS Carry?
Q14. What is the location of SSS in Type-1 Frame structure?
Q15. What is the location of SSS in Type-2 Frame structure?
Q16. How UE calculate PCI?
Q17. After Calculate PCI how UE validate PCI, is it correct or not?
Q18. What is the role of System Information’s in Power on procedure?
Q19. What is the difference between MIB and SIB in LTE?
Q20. What is P-compensation in cell selection procedure?
Q21. What is p-max in p-compensation?
Q22. What do you mean by cell priority in lte?
Q23. How many types of Priority available in lte?
Q24. What is Suitable Cell and Acceptable Cell what is the difference between them?
Q25. What is Barred Cell and Blacklisted Cell and difference between them?
Q26. What are Access Class (AC), How many AC are available in lte?
Q27. From where UE get Barring information?
Q28. What do you mean by Barring Factor, Barring Step, and Barring Time?
Q29. What are the durations of above Barring Information Elements have?
Q30. What kind of Information is carryin MIB==>PHICH?
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