LONG TERM EVOLUTION
Nagasai Panchakarla Shourov Kumar Roy Binoy Chemmagate Karthik Budigere Ramakrishna
1
AGENDA
LTE Features
3GPP Standards
LTE Key Technologies
LTE Network Architecture
Protocol Architecture
Quality of Service
Security
Roaming Architecture
Connection Management
Future of LTE and Deployments 2
LTE INTRODUCTION
All IP network
High Data rates
Low latency
Reduced cost per bit
Flat network architecture
High performance radio interface
Keeping up with other technologies
Flexibility in frequency allocation
Mobility 3
3GPP
3rd Generation Partnership Project (3GPP) is a collaboration of various telecommunication associations Standardization body and produces Technical Specifications, Technical Reports for 3G systems under the scope of International Telecommunication Union (ITU) 3GPP specifications are based on evolved Global System for Mobile Communications (GSM) specifications. Covers all GSM (including GPRS and EDGE) and W-CDMA specifications. Standards are structured as Releases TSG Structure consists of GERAN(GSM EDGE ), RAN, SA (Service & Systems Aspects), CT (Core Network & Terminals) Different Working groups under each TSG Following a TSG meeting revised versions of 3GPP specifications are published. *http://www.3gpp.org/Specifications
4
STANDARD RELEASES FDD Evolution
WCDMA .
TDD Evolution
TD-SCDMA
3GPP Release
Release 99/4
App year of n/w rollout
2003/4
HSDPA/ HSUPA
HSPA+
.
.
TD-HSDPA
TD-HSUPA
Release 5/6 2005/6-HSDPA 2007/8-HSUPA
Release 7 2008/9
LTE and HSPA+ .
LTE . Advanced
TD-LTE and TD-HSPA+
Release 8 2009/10
3GPP Study Initiated
The standardization process for LTE began at 3GPP Toronto workshop, 2004. Subsequently in December 2004, 3GPP started study to develop framework for evolution to achieve high data rates for both uplink and downlink transmissions, low latency The target was to have data rates three to four times of Release 6 HSDPA levels and two to three times of HSUPA levels. In 2007, E UTRA (evolved UTRA) was approved from study stage to first technical specifications. The first LTE base specifications are specified in 3GPP Release 8, December 2008.
5
STANDARD RELEASES Rel 8 First Release Standard for LTE Dec 2008
Rel 9 2nd Release 2009
Rel 10 LTE Advanced
HSDPA UL: 384 kbps
HSDPA/HSUPA UL: 5.76 Mbps
HSPA+ UL: 11.5 Mbps
LTE UL: 75 Mbps
DL: 14.4 Mbps
DL: 14.4 Mbps
DL: 28 Mbps
DL: 100 Mbps
6
LTE 3GPP REL 8 OVERVIEW
UL: SC-FDMA
DL: OFDMA
Bandwidth: 1.4,3,5,10,15,20 MHz
Modulation: QPSK, 16QAM,64QAM
Subcarrier spacing: 1.5 KHz
Increased spectral efficiency over Release 6 HSPA by a factor of two to four
Operation in both TDD and FDD modes
Coexisting with earlier 3GPP technologies
Optimized performance for 0-15 kmph, high performance for upto 120 kmph and establish communication upto 350 kmph Simplified architecture Interworking with other systems
7
E-UTRA OPERATING BANDS E-UTRA Operating Band
Uplink (UL) operating band BS receive UE transmit FUL_low – FUL_high
1
1920 MHz
–
1980 MHz
2110 MHz
–
2170 MHz
FDD
2
1850 MHz
–
1910 MHz
1930 MHz
–
1990 MHz
FDD
1805 MHz 2110 MHz
–
1880 MHz 2155 MHz
FDD
–
1785 MHz 1755 MHz
–
4
1710 MHz 1710 MHz
–
5
824 MHz
–
849 MHz
869 MHz
–
894MHz
FDD
61
830 MHz
–
840 MHz
875 MHz
–
885 MHz
FDD
7
2500 MHz
–
2570 MHz
2620 MHz
–
2690 MHz
FDD
8
880 MHz
–
915 MHz
925 MHz
–
960 MHz
FDD
1844.9 MHz 2110 MHz
–
1879.9 MHz 2170 MHz
FDD
–
1784.9 MHz 1770 MHz
–
10
1749.9 MHz 1710 MHz
–
11
1427.9 MHz
–
1447.9 MHz
1475.9 MHz
–
1495.9 MHz
FDD
12
698 MHz
–
716 MHz
728 MHz
–
746 MHz
FDD
13
777 MHz
–
787 MHz
746 MHz
–
756 MHz
FDD
14 15 16 17 18
788 MHz
–
798 MHz
758 MHz
–
768 MHz
FDD
Reserved Reserved 704 MHz
–
716 MHz
Reserved Reserved 734 MHz
–
746 MHz
FDD FDD FDD
815 MHz
–
830 MHz
860 MHz
–
875 MHz
FDD
19
830 MHz
–
845 MHz
875 MHz
–
890 MHz
FDD
20 21
832 MHz
–
862 MHz
791 MHz
–
821 MHz
FDD
1447.9 MHz
–
1462.9 MHz
1495.9 MHz
–
1510.9 MHz
FDD
... 33
1900 MHz
–
1920 MHz
1900 MHz
–
1920 MHz
TDD
34
2010 MHz
–
2025 MHz
2010 MHz
–
2025 MHz
TDD
35
1850 MHz
–
1910 MHz
1850 MHz
–
1910 MHz
TDD
36
1930 MHz
–
1990 MHz
1930 MHz
–
1990 MHz
TDD
37
1910 MHz
–
1930 MHz
1910 MHz
–
1930 MHz
TDD
38 39
2570 MHz
–
2620 MHz
2570 MHz
–
2620 MHz
TDD
1880 MHz
–
1920 MHz
1880 MHz
–
1920 MHz
TDD
40
2300 MHz
–
2400 MHz
2300 MHz
–
2400 MHz
TDD
3
9
Downlink (DL) operating band BS transmit UE receive FDL_low – FDL_high
Duplex Mode
FDD
FDD
Note 1: Band 6 is not applicable
• Release 9Technical Specification 3GPP TS 36.101 V9.3.0 (2010-03)
8
LTE LICENSING
First come first seerved
Beauty contest (comparative bidding)
Lottery
Auction (competitive bidding)
Recomendations for LTE Beauty contest and auction are best suited. Commitments concerning coverage. Roll out speed. Financial capacity. Expertise. Resource sharing. Nature of licensing and spectrum pricing.
9
LTE LICENSING
Germany’s LTE auction begins on Monday, April 12, 2010 800MHz, 1.8GHz, 2GHz and 2.6GHz are the four different bands of spectrum offered The auction has been declared as one of its kind in Europe paving way for other such auctions in the continent.
Source: http://wirelessfederation.com/news/24351-germany%E2%80%99s-lte-auction-begins/
10
LTE KEY TECHNOLOGIES
Radio Air Interface
Modulation and spectrum flexibility
MIMO
All IP flat networking architecture
11
LTE RADIO INTERFACE
OFDMA DL and SC-FDMA UL OFDMA has multiple orthogonal subcarriers and bandwidth can be adjustable per user User 1 User 2
Frequency
User 3
User 4 Time
SC-FDMA is similar to OFDMA and since its more power efficient, it can be used in hand held devices with battery power.
Single carrier, time space multiplexing
Consumes less power for transmission
Only a contiguous set of resource blocks can be selected for a user
12
MODULATION AND SPECTRUM FLEXIBILITY
For down modulation QPSK, 16QAM and 64QAM are used for payload channels (spectral efficient) For up modulation BPSK, QPSK, 8PSK and 16QAM are used BPSK and QPSK are used for control channels ( reliability and coverage) Adaptive modulation and coding 180 khz resource block All user equipments must support maximum bandwidth of 20 MHz Increase in wider bandwidth leads to cpmplexity and high power consumption Channel bandwidth BWChannel [MHz]
1.4
3
5
10
15
20
Resource blocks
6
15
25
50
75
100
13
MIMO
•
•
• • •
Tx1
Rx1
Tx2
Rx2
Transmission is done by converting serial bit stream into multiple parallel sub streams and sending via multiple antennas Each receiver sees the output of the channel, which is a combination of the outputs from the transmiters, separates the sub streams from mixed signals. In DL: Tx and Rx Diversity 14 In UL: Rx Diversity Increased complexity
ALL IP FLAT ARCHITECTURE
•
Software architecture evolution
•
Seamless interworking with IP based communication networks with simplified network architecture
•
•
Multimedia and circuit calls are mainly handled through converged IMS (IP Multimedia subsystem) core which is recently termed as VoLTE (voice over LTE) Supports mobility between different networks
15
LTE NETWORK ARCHITECTURE
LTE encompasses the evolution of the radio access through the E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) and is accompanied by an evolution of the non-radio aspects under the term ‘System Architecture Evolution’ (SAE). SAE includes the Evolved Packet Core (EPC) network. Together LTE and SAE comprise the Evolved Packet System (EPS) that contains fully packetswitched core network and radio access network. 16
EPS (EVOLVED PACKET SYSTEM)
EPS= Core Network (EPC) + Access Network (AN) EPS network is comprised of the Core Network and the Access Network, where the core network has many logical nodes and the Access Network has one node named as the evolved NodeB (eNodeB) which connects to the User Equipments (UEs).
17
EPS NETWORK ELEMENTS
18
CONNECTIVITY LAYERS
Internet Connectivity Layer: UE (User Equipment), E-UTRAN and EPC (all together the Evolved Packet System) represent the Internet Protocol Connectivity Layer. This layer is optimized only for IP based connectivity. Services Connectivity Layer: All services will be offered on top of IP. The Services Connectivity layer includes the operator services and internet. IMS (Internet Multimedia Sub-System) can be used in the Services Connectivity Layer to provide services on top of the IP connectivity layer. 19
Figure: System Architecture of LTE Network
20
THE ACCESS NETWORK : E-UTRAN The Access Network (E-UTRAN) simply consists of a network of eNodeBs. eNodeBs: The eNodeB is a radio base station that controls all the radio related functions. Generally the eNodeBs are distributed throughout the networks coverage area. The eNodeB is the termination point of all the radio related protocols. It relays the data between the radio connection and the corresponding IP based connectivity towards the EPC. 21
ENODEB
Figure: Overall E-UTRAN Architecture The eNodeBs are interconnected with each other by the interface X2. EnodeB connects to the EPC by the interface S1. More specifically it can be said that, EnodeB connects to the MME by means of the S1-MME interface and to the S-GW by means of the S1-U interface.
22
E-UTRAN FUNCTIONALITIES The radio related functions for which E-UTRAN is responsible can be summarized briefly as follows, Radio Resource Management: This includes all the functions which are related to radio bearers, such as, Radio bearer control, Radio admission control, Radio mobility control, Scheduling and dynamic allocation of resources to UEs in both uplink and downlink. Header Compression: E-UTRAN does the compression of IP packet headers. Security: Encryption is done when data is sent over the radio interface. Connectivity to the EPC: This includes signaling towards the MME and the bearer path towards the S-GW.
23
THE CORE NETWORK: EPC (EVOLVED PACKET CORE) The core network (EPC) has the following logical nodes: i. Mobility Management Entity (MME) ii. Policy and Charging Resource Function (PCRF) iii. Home Subscriber Server (HSS) iv. Packet Data Network Gateway ( P-GW) v. Serving Gateway (S-GW)
24
EPC: MME i. Mobility Management Entity (MME): MME is the control element in EPC that takes care of the signaling part between the Core Network and UE. MME also handles the security functions for both signaling and user data. The functions of MME can be categorized as follows,
Functions related to bearer management: It includes the establishment, maintenance and release of the bearers. Functions related to connection management: The establishment of the connection and security between the network and UE belong to these functions.
25
EPC: PCRF ii. Policy and Charging Resource Function (PCRF): It is the network element which is responsible for policy control. It also controls the flow-based charging functionalities in the PCEF (Policy Control Enforcement Function) located in the P-GW. The information PCRF provides to the PCEF is called the Policy and Charging Control (PCC) rules. 26
EPC: HSS iii. Home Subscriber Server (HSS): HSS
is the repository of users’ subscription data (EPS-subscribed QoS profile and any access restrictions for roaming etc.). It also contains the information about the PDNs to which the user can connect. The Authentication Center(AuC) can also be integrated with the HSS. 27
EPC: P-GW
iv. Packet Data Network Gateway ( P-GW): P-GW works as the mobility anchor point for the inter-networking with non-3GPP technologies such as CDMA 2000 and WiMAX networks. P-GW is also responsible for the IP address allocation for the User Equipment (UE). It does the QoS enforcement for Guaranteed Bit Rate bearers and flow based charging depending on the PCRF (Policy Control and Charging Rules Function) rules. It also performs the filtering based on TFTs (Traffic Flow Templates). 28
EPC: S-GW v. Serving Gateway (S-GW): S-GW works as the mobility anchor for interworking with other 3GPP technologies such as GPRS and UMTS. When an UE moves between eNodeBs, S-GW serves as the local mobility anchor for the data bearers. It performs some additional functions in the visited network, such as, collecting information (e.g. volume of data sent to or received from the user) for charging and legal interception.
29
EXAMPLE: S-GW
30
Figure: Architecture for 3G UMTS Internetworking
PROTOCOL ARCHITECTURE Protocol stacks User Plane Protocols - Packet Data Convergence Protocol (PDCP) - Radio Link Control (RLC) - Medium Access Control (MAC)
Control Plane Protocols - Radio Resource Control (RRC)
31
Figure ref- www.eventhelix.com/lte/lte-tutorials.htm
PDCP Processes RRC msgs in Control Plane and IP pacckets in User plane
Main functions - Header Compression - Security functions - Handover support - Discard User plane data
Types of data units - PDCP data PDU's Used in control plane and User plane
-PDCP control PDU's Used in feedback information in header compression and status reports in handover 32
Figure ref- www.eventhelix.com/lte/lte-tutorials.htm
PDCP FUNCTIONS(1/2)) Header Compression and decompression -
Robust Header Compression (ROHC)
Main functions - To support VOIP service as in CS-domain - VoIP packet is 32 bytes and Ipv4(40),IPv6(60) - After ROHC overhead is reduced to 4-6 bytes
Security - Ciphering and Deciphering user plane and control plane data. - Integrity protection and verification for control plane data
33
PDCP FUNCTIONS(2/2) Handover When UE moves from one cell to another, Two types are seamless and lossless
Seamless handover
Reasonable loss is tolerable but not delyay eg.VoIP
Lossless handover
Loss is not tolerable, retransmission
Discard user plane data
To avoid the buffer overflow. To prevent execessive delay. Timer expires in transmitter for discarding data.
34
RLC Main Functions
Segmentation and Reassembly
Retransmission
Reordering (HARQ)
RLC Entities
Transparent Mode RLC Entity
Unacknowledged Mode RLC Entity
Acknowledged mode RLC Entity
35
Figure ref- www.eventhelix.com/lte/lte-tutorials.htm
RLC MODES(1/2) Transparent Mode
RRC msgs without RLC configuration
Not used for User plane data transmission
Unidirectional data transfer service (Receiver or Transmitter)
Unacknowledged Mode Unidirectional, delay sensitive, point-multipoint
Segmentation and Concatenation of SDU’s
Reordering of PDU’s
Duplicate detection of PDU’s
Reassembly of SDU’s
36
RLC MODES(2/2) Acknowledged mode Bidirectional
Retransmission of RLC data PDU’s
Re-segementation of retransmitted RLC data PDU’s
Polling
Status Report
Status Prohibit
37
MAC
Multiplexing and Demultiplexing
Amount of data to be transmitted
Size of packets to be provided
Assuring QoS
38
Figure ref- www.eventhelix.com/lte/lte-tutorials.htm
MAC CHANNELS(1/2)
Two Logical channels
Control logical channels (Control data)
Data transfer for RLC
Broadcast Control Channel (BCCH) Paging Control Channel (PCCH) Common Control channel(CCCH) Multicast Control Channel (MCCH) Dedicated Control Channel (DCCH)
Traffic Channels Dedicated Traffic Channel (DTCH) Multicast Traffic Channel (MTCH)
39
MAC CHANNELS(2/2) Two transport channels
Data transfer for Physical layer
Downlink Transport Channels
Broadcast Channel (BCH)
Downlink Shared Channel (DL-SCH)
Paging Channel (PCH)
Multicast Channel (MCH)
Uplink Transport Channels
Uplink Shared Channel (UL-SCH)
Random Access Channel (RACH)
40
Figure ref- www.eventhelix.com/lte/lte-tutorials.htm
MAC FUNCTIONS
Scheduling Scheduling Information Transfer Random Access Procedure Uplink Timing Alignment Discontinous Reception Multiplexing Channel Prioritization
41
CONTROL PLANE PROTOCOLS
Radio Resource Control (RRC) Transfer of Common and dedicated NAS information, Notification of Incoming call Two mode of UE are RRC_IDLE and RRC_CONNECTED
Main Functions
System Information RRC connection Control Network Controlled inter-RAT mobility Measurement Configuration and Reporting Miscellaneous Functions (Dedicated NAS, UE Radio access capability)
42
RRC FUNCTIONS(1/2) System Information Master Information Block (MIB) System Information Block Type 1(SIB1) System Information Block Type 2(SIB2) SIB3-SIB8
RRC connection Control
Security Activation Connection establishment, modification and release DRB establishment, modification and release Mobility within LTE
43
RRC FUNCTIONS(2/2) Inter-RAT mobility
Handover to LTE
Mobility from LTE
Measurement Confugurations and Reporting
Measurement configuration
Measurement report triggering
Measurement reporting
44
DIFFERENT TYPES OF SELECTION
PLMN Selection
Cell Selection
Cell Reselection
Measurement Rules
Frequency/RAT evaluation Cell Ranking Accessiblity verification Speed dependent scaling Cell access restrictions Any Cell selections Closed subscriber Group
45
QUALITY OF SERVICE (QOS) Two types of bearers
Minimum GBR (VoIP)
Non-GBR (Browsing ,File download)
QCI (QoS Class Identifier)
Priority
Packet delay budget
Packet loss rate
ARP ( Allocation and Retenstion Priority )
Call admission control
46
SECURITY Ciphering (both planes) and Integrity Protection (control plane) Key Management
Common secret key KASME (Access Security Management Entity) between HSS and UE Authetication by checksums and keys (random number+ common shared key)
Two types of keys
AS base Key KeNB and AS derived keys
NULL Ciphering algorithm for emergency calls 47
ROAMING ARCHITECTURE
48
ROAMING ARCHITECTURE
Roaming is one of the powerful feature which enables the users to access the mobile network which he is not subscribed to(Different location). LTE supports the roaming feature by establishing the interface between the visited Gateway with the home PDNgateway. This interface is known as S8 Interface.
The S8 interface allows users to access home operators services even from the visited network. There is interface between the visited MME and the HSS(Home Subscriber Serer) called S6a. This is used for billing and updating the location of the user. 49
CONNECTION MANAGEMENT
LTE State Transition 50
INITIAL ATTACH The Initial attach involves the following steps, LTE Cell Search
Primary synchronization signal Secondary synchronization signal
Random Access Procedures RRC Procedures
RRC Connection Establishment Initial Security Activation RRC Connection Reconfiguration Bearer Establishment 51
INITIAL ATTACH PROCEDURE
52
PAGING PROCEDURE
53
S1 BASED HANDOVER PROCEDURE
54
X2 BASED HANDOVER PROCEDURE
55
DEPLOYMENT
The complete migration to LTE is expected to happen by 2015 The best optimal way of deployment is to implement LTE for data-only services and later extend it to voice based services. The worlds first LTE deployment is made by Teliasonera (December 2009) in Sweden and Norway. Ericsson is providing the LTE solutions for it. 130 operators are committed to deploy LTE by 2015. Some of the operators promised for LTE deployment are AT&T, Verizon, Vodafone, DNA, Elisa KT, SKT, NTTDocomo, ZAIN, BSNL and more …. LTE or Wimax … wait n watch
56
FUTURE OF LTE
LTE revenues expected to be $70 billion pa and also over 100 million users by 2014 says the Juniper Research. Main markets will be North America, Europe, Far east and china.
57
LTE ADVANCED
LTE Advanced expected to fulfill the IMT advanced requirements for the 4G technology
LTE Advanced will be included in the 3GPP release 10.
The features in LTE advanced are,
Increased data rates Carrier aggregation Spatial Multiplexing in antennas Coordinated multiple transmitters and receivers Energy Efficiency Relay Functionality
58
LTE VENDORS
LTE Solution Providers
59
LTE VENDORS •
LTE Chipset Providers
60
LTE DEVICES
61
62
