Long Term Evolution (LTE) and System Architecture Evolution (SAE) 3 May 2007 www.nethawk.fi Long Term Evolution (LTE) and System Architecture Evolution (SAE)

Contents Why LTE/SAE? LTE Overview 3 May 2007 www.nethawk.fi Contents Why LTE/SAE? LTE Overview LTE technical objectives and architecture LTE radio interface RAN interfaces SAE architechture [3GPP TS 23.401] Functions of eNB Functions of aGW GTP-U tunneling Non-3GPP access tunneling Testing challenges with LTE LTE standardisation status

Why LTE/SAE? Packet Switched data is becoming more and more dominant 3 May 2007 www.nethawk.fi Why LTE/SAE? Packet Switched data is becoming more and more dominant VoIP is the most efficient method to transfer voice data  Need for PS optimised system Amount of data is continuously growing  Need for higher data rates at lower cost Users demand better quality to accept new services High quality needs to be quaranteed Alternative solution for non-3GPP technologies (WiMAX) needed LTE will enhance the system to satisfy these requirements.

LTE Overview 3GPP R8 solution for the next 10 years 3 May 2007 www.nethawk.fi LTE Overview 3GPP R8 solution for the next 10 years Peaks rates: DL 100Mbps with OFDMA, UL 50Mbps with SC-FDMA Latency for Control-plane < 100ms, for User-plane < 5ms Optimised for packet switched domain, supporting VoIP Scaleable RF bandwidth between 1.25MHz to 20MHz 200 users per cell in active state Supports MBMS multimedia services Uses MIMO multiple antenna technology Optimised for 0-15km/h mobile speed and support for up-to 120-350 km/h No soft handover, Intra-RAT handovers with UTRAN Simpler E-UTRAN architecture: no RNC, no CS domain, no DCH

LTE technical objectives and architecture 3 May 2007 www.nethawk.fi LTE technical objectives and architecture User throughput [/MHz]: Downlink: 3 to 4 times Release 6 HSDPA Uplink: 2 to 3 times Release 6 Enhanced Uplink Downlink Capacity: Peak data rate of 100 Mbps in 20 MHz maximum bandwidth Uplink capacity: Peak data rate of 50 Mbps in 20 MHz maximum bandwidth Latency: Transition time less than 5 ms in ideal conditions (user plane), 100 ms control plane (fast connection setup)

Mobility: Optimised for low speed but supporting 120 km/h 3 May 2007 www.nethawk.fi Mobility: Optimised for low speed but supporting 120 km/h Most data users are less mobile! Simplified architecture: Simpler E-UTRAN architecture: no RNC, no CS domain, no DCH Scalable bandwidth: 1.25MHz to 20MHz: Deployment possible in GSM bands.

From Ericsson, H. Djuphammar 3 May 2007 www.nethawk.fi LTE radio interface New radio interface modulation: SC-FDMA UL and OFDMA DL Frequency division, TTI 1 ms Scalable bandwidth 1.25-20MHz TDD and FDD modes UL/DL in either in same or in another frequncy OFDMA has multiple orthogonal subcarries that can be shared between users quickly adjustable bandwith per user SC-FDMA is technically similar to OFDMA but is better suited for uplink from hand-held devices Single carrier, time space multiplexing Tx consumes less power From Ericsson, H. Djuphammar

LTE/SAE Keywords aGW Access Gateway eNB Evolved NodeB 3 May 2007 www.nethawk.fi LTE/SAE Keywords aGW Access Gateway eNB Evolved NodeB EPC Evolved Packet Core E-UTRAN Evolved UTRAN IASA Inter-Access System Anchor LTE Long Term Evolution of UTRAN MME Mobility Management Entity OFDMA Ortogonal Frequency Division Multiple Access SC-FDMA Single Carrier Frequency Division Multiple Access SAE System Architecture Evolution UPE User Plane Entity

RAN interfaces X2 interface between eNBs for handovers 3 May 2007 www.nethawk.fi RAN interfaces eNB X2 interface between eNBs for handovers Handover in 10 ms No soft handovers Interfaces using IP over E1/T1/ATM/Ethernet /… Load sharing in S1 S1 divided to S1-U (to UPE) and S1-C (to CPE) Single node failure has limited effects S1 aGW eNB X2 S8 aGW X2 eNB

SAE architecture [3GPP TS 23.401] 3 May 2007 www.nethawk.fi SAE architecture [3GPP TS 23.401] GERAN HSS PCRF Gb UTRAN GPRS Core Iu S6 Rx+ S7 X1 S3 S4 Operator IP services (including IMS, PSS, ...) eNB MME UPE SAE GW PDN SAE GW SGi S1 S11 S5 X1 X2 aGW S2 Evolved Packet Core eNB Non-3GPP IP Access Evolved RAN

SAE architechture [3GPP TS 23.401] 3 May 2007 www.nethawk.fi SAE architechture [3GPP TS 23.401] TBD eNB HSS PCRF S1 S7 S6a aGW S5 PDN SAE GW S11 SAE GW TBD eNB X2 IASA S8 SGi S11 aGW Operator IP service, including IMS TBD Short descriptions of the LTE interfaces [Source: ] eNB aGW = MME/UPE Evolved RAN

3 May 2007 www.nethawk.fi Functions of eNB Terminates RRC, RLC and MAC protocols and takes care of Radio Resource Management functions Controls radio bearers Controls radio admissions Controls mobility connections Allocates radio resources dynamically (scheduling) Receives measurement reports from UE Selects MME at UE attachment Schedules and transmits paging messages coming from MME Schedules and transmits broadcast information coming from MME & O&M Decides measurement report configuration for mobility and scheduling Does IP header compression and encryption of user data streams

3 May 2007 www.nethawk.fi Functions of aGW Takes care of Mobility Management Entity (MME) functions Manages and stores UE context Generates temporary identities and allocates them to UEs Checks authorization Distributes paging messages to eNBs Takes care of security protocol Controls idle state mobility Control SAE bearers Ciphers & integrity protects NAS signaling

Takes care of User Plane Entity (UPE) functions 3 May 2007 www.nethawk.fi Takes care of User Plane Entity (UPE) functions Terminates for idle state UEs the downlink data path and triggers/initiates paging when downlink data arrive for the UE. Manages and stores UE contexts, e.g. parameters of the IP bearer service or network internal routing information. Switches user plane for UE mobility Terminates user plane packets for paging reasons

3 May 2007 www.nethawk.fi Functions S1

LTE Control Plane NAS NAS PDCP PDCP RRC RRC RLC RLC MAC MAC PHY PHY UE 3 May 2007 www.nethawk.fi LTE Control Plane UE eNB aGW NAS NAS PDCP PDCP RRC RRC RLC RLC MAC MAC PHY PHY S1

LTE User Plane IP IP PDCP PDCP RLC RLC MAC MAC PHY PHY UE aGW eNB S1 3 May 2007 www.nethawk.fi LTE User Plane UE eNB aGW IP IP PDCP PDCP RLC RLC MAC MAC PHY PHY S1

Header compression & encryption 3 May 2007 www.nethawk.fi GTP-U tunneling Header compression & encryption UE UPE X1 eNB S1 S11 SAE GW S5 PDN SAE GW SGi Server Radio L1 MAC PDCP IPv6/v4 u Application TCP/UDP RLC IPv6/v4 TCP/UDP Application IP UDP GTP-U L2 L1 Radio L1 MAC RLC PDCP ENC IP UDP GTP-U L2 L1 IP UDP GTP-U L2 L1 L1 L2 IP UDP GTP-U L1 L2 L2 L1

Non-3GPP access tunneling 3 May 2007 www.nethawk.fi Non-3GPP access tunneling UE AP PDN SAE GW HA Server WLAN S2 SGi Application TCP/UDP IPv4/6 IPv4/6 MIP MIP UDP UDP IP IPv6/v4 IP IP IP IP L1 L2 L1 L2 L2 IP L1 L2 L2 L2 L2 L1 L1 L1 L1

Testing challenges with LTE 3 May 2007 www.nethawk.fi Testing challenges with LTE How to optimize radio interface? No radio measurement data available since no ”Iub-like” interface Increased complexity of eNB need for analysis of internal traffic need for internal debugging need for analysis of protocol data How to test inter-eNB handovers? How to test inter-system handovers? How to test voice and video broadcast? 10x higher throughput  How to verify eNB performance? How to test application level QoS? How to verify SLA? How to handle network management challenges?

LTE standardisation status 3 May 2007 www.nethawk.fi LTE standardisation status Specification work done by 3GPP TS RAN. First 3GPP specs expected 3Q2007 First trials expected 2008 Commercial release expected 2009 NetHawk is member in 3GPP and follows closely the standardisation work 2007 2008 2009 Commercial Release Specification Trials First 3GPP specs expected 3Q/2007

3 May 2007 www.nethawk.fi