HSN2002 IP-based Radio Access Networks

Transcription

1 HSN2002 -based Radio Access Networks

2 Contents Introduction Transport RAN Open RAN -based RAN TelCo s -based RAN Architecture Technical Study Conclusion

3 Introduction What is -based RAN? Main Benefits of Transport Re-use of potentially available transport infrastructure (e.g. in corporate environments and/or hot spots) as universal transport technology throughout the whole mobile network will bring benefits: sharing of infrastructure similar network management skills for transport functions

4 Introduction -based RAN Concepts Flexible and independent scaling of different network functions Adoption of existing or new IETF protocols to enhance the flexibility, robustness and functionality of the RAN Potential basis for the support of -based network applications and services within the RAN Decisive step towards the long term 3GPP All- vision

5 Introduction RAN Evolution 3G 3.5G 4G Current transport RAN RAN Point-to-point Concentration Routing Transport Point-to-point Node B Link Node B Re-parenting Distributed RRM R99/R4 RRM Iu R5/R6? Iu RRM Iu RRM R? RRM Iu All Network Network Call Server Transport Network Aggregation Location Server Iub Iub Vocoder Pool O&M Iub Iub Iub Iub Node B Node B Node B Node B : Radio Network Controller RRM: Radio Resource Management

6 Transport in UTRAN: 3GPP Transport Requirements Use already standardized protocols, e.g. IETF protocols for related parts RNL shall be independent of the TNL Impact on the RNL shall be minimized but there could be some minor changes to the RNL, e.g. addressing Support coexistence of the -based and -based transport options: Where a UTRAN node does not support both interfaces (R99 and later releases) and interfaces, an TNL interworking function is required Provide QoS: TNL shall provide appropriate QoS requested by the RNL Mechanisms that provide QoS must take into account both UTRAN traffic(control plane, user plane, and O&M) and non-utran traffic Provide utilization of transport resources Iub/Iur protocols shall operate efficiently on low speed point to point links Provide Layer 1/ Layer 2 independence Layer 1 and Layer 2 shall be capable to fullfill the QoS requirements set by the higher layers

7 Transport in UTRAN: 3GPP Transport Requirements (cont d) Provide transport flexibility: No preference to routed vs point-to-point networks Use individual flows addressing Support identification of UTRAN nodes by one or several address Support requirements on signaling bearers

8 Transport in UTRAN: 3GPP User Plane Proposed Solutions Composite (C) Solution Multiple C packets of variable size in one C container for an efficient use of the bandwidth of the links Segmentation/re-assembly mechanism FP PDU FP PDU Segment FP PDU Segment FP PDU Segment C Packet Payload C Packet Payload C Packet Payload Header Header C Packet Header C Packet Payload C Packet Header C Packet Payload C Packet Header C Packet Payload FP PDU is segmented in 3 packets

9 Transport in UTRAN: 3GPP User Plane Proposed Solutions (cont d) Lightweight Encapsulation(LE) Solution / or as transport layer Encapsulated payload of a variable number of multimedia data packet(mdp) and multiplexing header(mh) LE / or encapsulation format PPP/HDLC Framing (20) (8) MH1 (1-3) MDP1 MH2 (1-3) MDP2 MH3 (1-3) MDP3 MH: Multiplexed Header, MDP: Multiplexed Data Payload (20) TID MH1 (1) (1-3) MDP1 MH2 (1-3) MDP2 MH3 (1-3) MDP3 TID: Tunnel Identifier

10 Transport in UTRAN: 3GPP User Plane Proposed Solutions (cont d) PPP-mux based Solution Method to reduce the PPP framing overhead used to transport small packets, e.g. voice frames, over slow links Multiple PPP encapsulated packets in a single PPP frame PPP multiplexed frame options over / over L2TP(TCRTP) PPP-mux frame with multiple subframes HDLC Hdr (1) PPPmux ID (0x59) PPP Header(2) PFF LXT (1-2) Length 1 PPP Prot. Field 1 (0-2) c 1 (2) Payload 1 Information 1 PFF LXT (1-2) Length N PPP Prot. Field N (0-2) c N (2) Payload N Information N CRC (2)

11 Transport in UTRAN: 3GPP User Plane Proposed Solutions (cont d) MPLS Solution Method of forwarding packets, while reusing the existing routing protocols, e.g. OSPF, BGP Advantages of routing with MPLS Coexistence with hop-by-hop routing Traffic engineering capabilities Flexibility due to label semantics and stacking Transparent and fast routing Narrow-band Link /MPLS Network Compress /Decomp. Node Node B Payload Frame Payload Frame Payload Frame Payload Frame Payload Frame Payload Frame c/ c/ MPLS* MPLS* MPLS MPLS Class of Service 1 LSP *:may also be compressed depending on Class of Service 2 LSP the compression technique used. (see2.6) Class of Service 3 LSP

12 Transport in UTRAN: 3GPP Quality of Service QoS Mechanisms At layer, Diffserv, RSVP or over-provisioning considered UTRAN Hop-by-Hop QoS Approach QoS differentiation in the backbone Some problems Definition to inform the edge router about the needed quality classes Edge router functionality that the standard design relies on Interworking of PPP-mux with MC-PPP UTRAN End-to-End QoS Approach QoS differentiation for the UTRAN traffic flows inside UTRAn NEs Composit, LE Tunneling PPP protocol via L2TP(TCRTP) PPP-mux

13 Transport in UTRAN: 3GPP Transport Network Bandwidth Utilization Multiplexing Reducing the impact of the size of the / headers in a packet Multiplexing location: application level, transport level Transport level multiplexing End-to-end multiplexing transparent to intermediate transport nodes Last Mile multiplexing terminated in Edge router Last Mile multiplexing + Routed network multiplexing Resource Management Functions to be considered Admission control Policing Reservation of resources Methods of resource allocation Over-provisioning Allocation of aggregates of flows Allocation per flow Centralized or distributed admission control Signaling(e.g. RSVP) for distributed admission control

14 Transport in UTRAN: 3GPP Transport Network Bandwidth Utilization (cont d) Header Compression Standard compression techniques Compression with differential coding: re-synchronization problem Compression without differential coding: quick recovery from out of synchronization Header Compression(RFC2507): for PDCP(3GPP TS25.323) Compressing //RTP Headers for Low-Speed Serial Links(RFC2508)

15 Transport in UTRAN: 3GPP User Plane Transport Signaling Solution without Access Link Control Application Protocol(ALCAP) Establishment/maintenance/release of user plane transport bearers with TNL signaling protocol Transport bearer termination points: related RANAP message Transport layer address IE: address to be used for user plane transport Iu transport association IE: GTP tunnel endpoint identifier RNL Termination RNL Protocol RNL Termination TNL Termination TNL Protocol (ALCAP) TNL Switching TNL Protocol (ALCAP) TNL Termination LE Solution Point to Point Link /Node B LE Tunnel Cloud /Node B LE Tunnel

16 Transport in UTRAN: 3GPP Layer 1 and Layer 2 Independence Layer 1 and Layer 2 in QoS and/or in transport resource efficiency Layer 2 Options Considerations QoS differentiation (queuing scheme, segmentation and scheduling functionality,..) Efficiency L2 not standardized Provide the most freedom for the operators to build their transport network L2 standardized Restrict flexibility for operators In UTRAn NEs, PPP protocol with its extensions PPP-mux, Multi-Link(ML)/Multi- Class(MC)-PPP

17 Transport in UTRAN: 3GPP Radio Network Signaling Bearer Iub RNL Signaling Bearer Iub signaling bearer protocol stack Iub Iub NBAP NBAP Adaptation Layer 2 Layer 2 Layer 1 Layer 1 without Adaptation Layer with Adaptation Layer RNS Signaling SS7 SCCP-User Adaptation Layer(SUA) protocol SUA// over (or HDLC-PPP, etc)

18 Transport in UTRAN: 3GPP Radio Network Signaling Bearer (cont d) RANAP Signaling Use of to minimize the changes on UTRAN RNL and to reduce the number of different variants of any application signaling protocol RNL signaling bearers on Iu interface: illustration Iu Radio Network Layer NBAP Transport Layer Adaptation Layer 2 Layer 1

19 Transport in UTRAN: 3GPP Radio Network Signaling Bearer (cont d) SCCP/M3UA versus SUA Comparison of SUA with SCCP/M3U: Benefits With M3UA, the signaling point is required to support different flavours of SCCP if it has to inter-operate with different national systems One less protocol layer with elimination of SCCP SUA allows the network to route the messages SUA allows the messages routing using Global Titles without involvement of point codes in - case SUA provides much better scalability and flexibility for signaling network implementation in all network compared to the SCCP/M3UA option The powerful end-to-end addressing and routing capability od SUA can greatly reduce the signaling transfer latency The M3UA nodes need to be addressed by point codes at M3UA layer and by addresses at layer There are some function redundancies in SCCP/M3UA/ stack mode The capabilities of SUA make SCCP and M3UA unnecessary and SUA can be considered preferable in terms of efficiency and implementation complexity Comparison of SUA with SCCP/M3U: Drawbacks SUA doesn t support MTP-3 user protocols such as ISUP ans BICC Interworking between SUA and SCCP/M3UA is introduced In use of common principles, M3UA would be similar to MTP3 network

20 Transport in UTRAN: 3GPP Radio Network Signaling Bearer (cont d) SCCP/M3UA versus SUA (cont d) Comparison of SCCP/M3U with SUA: Advantages The M3UA takes care of other MTP-3 user than SCCP like ISUP, BICC and H.248 No special interworking functions are required for interworking with Rel4 Addition of a new protocol will impose additional cost of training, testing, new equipment(protocol analyzer) and signaling gateway functionality The introduction od SUA as an alternative to M3UA+SCCP will introduce options in implementations, which will sooner or later lead to increased cost The introduction of SUA as an alternative to M3UA+SCCP will introduce options in the networks, and between networks The operators can apply similar principles for network planning, network management and network operation as for the MTP network For the case of a smooth transition towards an network the SCCP+M3UA solution reuses the complex SCCP functionality and to rebuild this functionality can only increase development costs and lead to interworking problems The operator can reuse the GT analysis already provided by data builds in SCCP, which is proven to work in existing networks

21 Transport in UTRAN: 3GPP Radio Network Signaling Bearer (cont d) Interworking of SCCP/M3UA and SUA Interconnecting operator networks with SUA Signaling Point 1 Signaling Point 2 Network Network Signaling Point N Signaling Point 1 Network Network Signaling Point 2 associations SUA Relay SUA Relay associations SUA Relay SUA Relay associations Signaling Point N

22 Transport in UTRAN: 3GPP Transport and Routing Architecture Transport Network Architecture: Example Edge Router Edge Router Node B Edge Router Network of Routers Node B Node B Edge Router Node B

23 Transport in UTRAN: 3GPP Backward Compatibility with R99/Coexistence with Nodes Interworking Cases IWU IWU IWU Node B Node B Interworking Unit(IWU) in Transport Network Layer based based RNL IWU RNL TNL TNL

24 Transport in UTRAN: 3GPP Backward Compatibility with R99/Coexistence with Nodes Transport Network Control Plane Interworking -based IWU -based Q ALCAP ALCAP Q MTP-3b Q MTP-3b Q Q SSCF SSCOP SSCF SSCOP L2 L2 L1 L1 L1 L1 /AAL2

25 Transport in UTRAN: 3GPP Backward Compatibility with R99/Coexistence with Nodes Interworking between External Dual Stack and Rel4/R99 R99 Signaling Gateway R4 RNSAP RNSAP SCCP SCCP SUA SUA MTP-3b MTP-3b SSCF-NNI SSCOP SSCF-NNI SSCOP L2 L2 L1 L1 L1 L1 External Dual Stack R4/R99

26 Transport in UTRAN: 3GPP Security Sec Architecture Protocol providing authentication and integrity protection in two architectures: End-to-end security provisioning between hosts Gateway to gateway Host to host security Transport mode: integrity and authentication cover only transport protocol(above ) and higher protocols Tunnel mode: header is protected Security Features Incorporate a cookie exchange mechanism at association establishment Designed to prevent unauthorized connections to be set up at transport level

27 Transport in UTRAN: 3GPP Iu-CS/Iu-PS Harmonization GTP-U for Iu User Plane Iu-PS domain GTP-U header size: 8 octets, 12 octets GTP s header size: 6 octets GTP-U header whould be defined that is optimized for real-time applications Iu-CS domain GTP-U for Iu-CS interface over transport RTP as alternative to GTP-U RTP for Iu-CS Interface RTP// based Iu-CS user data transport RTP selected used in the 3GPP circuit-switched core network for Nb interface has capability that is needed for real-time services over Iu-CS interface IETF protocol Bandwidth utilization

28 OpenRAN: MWIF Architectural Characteristics and Conceptual Model Open Flexible Distributed Core Network Scalable Access GW Radio Controller Routed Cloud Routed Cloud Radio Frame Routed Cloud Radio Frame Routed Cloud Radio Layer 1 Cell Bearer GW Feb. 21, * 0 # HSN

29 OpenRAN: MWIF Architectural Requirements Support the current 2G and 3G radio technologies Provide at least equivalent functionality to existing RAN architecture Transport bearer and control traffic based on technology Use IETF protocols wherever applicable Support v6 as well as v4 Consist of separated control and bearer function Support distributed control and bearer function Support distribution of cell dependent and UE control and bearer function Support QoSs such as multiple transport and radio QoS levels, including in handoff scenarios application QoS in the RAN and over the air multiple levels of static QoS as well as dynamic QoS Allow optimized use of different wireless access technologies Support necessary functions to ensure that the necessary availability and reliability can be achieved Support deployment within LAN, MAN, WAN environment

30 OpenRAN: MWIF Architectural Requirements (cont d) Use IETF-based standard network management protocols Interoperate with the MWIF core network architecture Support AAA to handle multiple radio channel authentiation protocols to be present in the RAN or provided by core network functions

31 OpenRAN: MWIF Operator Requirements Support open interfaces between any network entities in the OpenRAN Support interoperability with legacy(2g/3g CN and AN) networks Support network deployment in public as well as in enterprise/corporate environments Provide network operators the ability to expand specific RAN functional entities independently of other entities Provide functions to protect its network resources and traffic from unauthorized control access Provide Plug and Play to make easy and reliable equipment installation without specific technical knowledge, reducing the cost for installation to make easy deployment of a distributed network system to make easy and hot exchange of the network equipment when it is broken or version incremented Provide the ability to integrate with legacy RAN and core network infrastructure to allow a smooth migration

32 OpenRAN: MWIF Handoff Requirements Provide equivalent handoff mechanisms that equal or exceed current cellular performance, and work for both voice and data Allow handoff between different radio access technologies on a single RAN for load balancing purposes Meets QoS requirements (e.g. low latency) Minimize transport data loss within the constraints of the medium Support inter-ran handoff by working together with core network mobility management

33 OpenRAN: MWIF Network Architecture Flat, distributed architecture User Plane related Entity CN = Multimedia Subsystem Macro Mobility IFs for C-plane Entities Access NW IF Policy Server Control Plane related Entity OAM&P Profile Server Distributed Control Severs A-GW A-GW Authen. Server Author Server Account Server Wireless Tech. Indepemdent IF RAN = Pure Network Micro Mobility Wireless-Wired IF -addr. Mngr. NRM Name Server RRM AP Node B Node B BSC+α Wireless LAN BTS GSM Other service relating servers: Media Gateway, etc. MT UE UE MS A-GW : Access Gateway NRM : Network Resource Management RRM : Radio Resource Management

34 OpenRAN: MWIF Mapping to the UTRAN Architecture Iub-C C/ S Bearer Plane Control Plane Iub-C Radio L1 Node B Iub-U Common RRM Func Iur-C Cell Controller Cell Bearer Gateway Paging Broadcast UE Geo-location Iur-U Iur-C Mobile Control User Radio Gateway Iur-C Iups-C Iups-U New reference point in MWIF Existing 3GPP reference point

35 OpenRAN: MWIF Mapping to 3GPP2 IOSv4.1 RAN(cdma2000 RAN) Architecture Abis_sig Target BSC Source BSC BSC UE Geo-location A7 Bearer Plane Control Plane Radio L1 BTS Abis_sig Abis_traffic Common RRM Func A3_s Cell Controller Cell Bearer Gateway Paging Broadcast A3_U Mobile Control User Radio Gateway A11 Iups-U New reference point in MWIF Existing 3GPP2 reference point

36 -based RAN Requirements Support of GERAN and UTRAN radio technologies, hooks for possible other radio technologies Open multivendor RAN architecture and interfaces Optimized utilization of the radio interface resources Optimized location of operational and radio functions to maximize performance Co-ordinated management of multi-radio environments Optimized utilization of transmission resources especially on the last mile Distributed architecture enabling maximum modularity and scalability Need to be able to add new transport options without affecting the radio network layer, and the ability to adapt the radio network layer without affecting the transport Evolution of the RAN architecture shall re-use current interface standards and interface principles 3GPP UTRAN interface protocols IETF protocols when applicable

37 -based RAN Requirements (cont d) Transport based on layer services layer 1 / layer 2 independence, provided that layer service level is achieved Quality of Service, mechanisms to support traffic engineering and bandwidth management transport solution based on the UTRAN Rel.4 transport, where applicable Support of location based services Network security and user access security must be guaranteed Interoperability with legacy(2g/3g) networks and mobile terminals Evolution path from existing radio systems towards -based RAN

38 -based RAN Principles of -based RAN Separation of Different Network Functions: User plane function Control plane function Transport plane function Flexible Distributed Architecture which allows for: Flexible deployment Load sharing Redundancy concepts Use of Transport Re-use of IETF Protocols e.g. RAN-internal mobility management based on Mobile mechanisms

39 -based RAN * 0 # * 0 # * 0 # 3GPP -based Mobile Comm. Networks with Legacy RAN MSC/VLR HLR HSS AuC SGSN PSTN Network E D H CAP Uu Node B RNS (UTRAN) Iub F Iu-CS EIR Gf SGSN Gr Gc D/C GGSN CAP SCP CSCF Uu Node B Iub Iur Iu-PS Gn MSC/GMSC server Uu irns ( UTRAN) inode B i iiu-ps iiu-cs (RANAP) Gi Gi Gi Managed Core Network (QoS, COS) Mc ISUP/ Mm PGW T-SGW Internet iiub iiu (RTP) Mr Mg ISUP/ Mc iiub iiur Uu inode B i MGW PSTN Network MRF MGCF UE RAN CN

40 Telco s -based RAN Architecture Nokia s -based RAN Architecture Control Plane Signaling Control Common Radio Resource Management Radio Access Server CRRM Server O&M Server User & GW Plane Interface GW Gb A, Iu-CS IOS(IS-41) Multi-Standard Base Stations - GSM/EDGE - TDMA/EDGE - WCDMA - 1XTREME v6 based Mobility Interface Iu-PS - WLAN v6 Core GW

41 Telco s -based RAN Architecture Simens -based RAN Architecture Radio Network Control Plane Functions Radio Network Control Interworking Functions CN with Rel'99 Iu Control Plane Rel'99 RNS User Plane Transport Plane Core Networks Radio L1 Functions Radio Network User Plane Functions Transport Functions

42 Telco s -based RAN Architecture Alcatel s -based RAN Architecture Core Network - Gateway to Core Network - Mobility anchor point - Dedicated channels: Ciphering, RLC, MAC-d, DHO - Shared channels: Ciphering, RLC, MAC-d Gateway to CN UE-scaled Control Functions UE control - Traffic concentration Network Cell control - Shared channels cell scheduling TNL TNL TNL Cell-scaled Control Functions Node B Node B Node B TNL

43 Technical Study Transport RAN Protocol Stack: example 1 -based Node B -based APP NBAP NBAP UP(CS) APP UP(PS) RANAP RNSAP RRC FP AAL2 PDCP RLC MAC AAL2 BMC SABP TCP GTP-U SCCP M3UA W-CDMA iiub Iu-CS(CP) Iu-CS(UP) Iu-PS Iub-GW Iur-GW Q Q Traffic & Signaling Q Q NBAP Relay SSCF-UNI SSCOP UP Relay FP FP AAL2 AAL2 Signaling Traffic UP Relay GTP-U FP AAL2 RNSAP Relay SCCP SCCP M3UA MTP-3b SSCF-UNI SSCOP iub iub iiub iiur iur iur

44 H.J.Park Technical Study Transport RAN Protocol Stack: example 1a UE irts i other i CBC APP MM/SM/CC APP APP APP APP NBAP NBAP UP(CS) UP(PS) RANAP RNSAP RNSAP RANAP UP S/M/RTP/ RTCP/RSVP PPP RRC RRC PDCP BMC PDCP BMC RLC RLC MAC MAC SABP SCCP SCCP SABP FP FP GTP-U M3UA M3UA GTP-U TCP TCP AAL2 AAL2 WCDMA WCDMA (Radio) Uu E1/STM-1 iiub STM-1 iiur STM-1 Iu-BC R99 RTS Iub-GW isgsn(cn-ps) iggsn(cn-ps) APP NBAP APP (MM/SM/CC) RANAP UP APP UP (Routing) Q Q Q Q Traffic UP Relay Signaling Traffic/Signaling SCCP PPP FP NBAP Relay FP FP M3UA GTP-U GTP-U SSCF-UNI SSCF-UNI SSCOP SSCOP AAL2 AAL2 AAL2 Iub E1/STM-1 iiub E1/STM-1 iiu-ps STM-1 Gn STM-1 Gi from/to Multimedia Networks R99 Iur-GW MGW(CN-CS) imsc(cn-cs) APP APP APP UP(CS) UP(PS) RANAP RNSAP UP RANAP Q Q Q Q RNSAP Relay SABP SCCP UP Relay SCCP SCCP H.248 / MEGACO H.248 / MEGACO SCCP GTP-U MTP-3b GTP-U MTP-3b M3UA GTP-U RTP/RTCP M3UA TCP SSCF-NNI SSCOP AAL2 SSCF-NNI SSCOP AAL2 Iur STM-1 iiur STM-1 iiu-cs(up) STM-1 iiu-cs(cp) STM-1 Mc STM-1

45 Technical Study H.J.Park Transport Mobile Comm. Network Protocol Stack: example 2 iue iutran imsc(cn-cs) MGW(CN-CS) MGW(CN-IM) CBC APP MM/SM/ CC RTS APP APP APP APP APP APP S/M/RTP/ RTCP/RSVP NBAP NBAP UP(CS) UP(PS) RANAP RNSAP RANAP MAP CAP UP UP PPP RRC RRC PDCP BMC PDCP BMC RLC RLC TCAP TCAP MAC MAC SABP SCCP H.248 / MEGACO SCCP SCCP SCCP H.248 / MEGACO H.248 / MEGACO SABP FP FP GTP-U M3UA M3UA M3UA M3UA GTP-U RTP / RTCP RSVP RTP / RTCP RSVP TCP TCP AAL2 AAL2 Time Slot WCDMA WCDMA PCM Uu Uu iiub iiu-ps 1 iiu-cs(up) iiu-cs(cp) Mc iiu-cs(cp) D WIN iiu-cs(up) Nb Mc Nb 2 Mc 1 (Radio) iiu-cs(cp) imsc(cn-cs) Nc igmsc(cn-cs) T-SGW(CN-IM) Mc Mc CAP iue Uu iutran iiu-cs(up) MGW(CN-CS) Nb MGW(CN-IM) 2 PSTN/Legacy/External 1 CBC iiu-ps D isgsn(cn-ps) Gf Gr EIR C Gn Gc CAP Gi iggsn(cn-ps) Gi Gi MRF(CN-IM) Mr Mc Mg Gi 3 MGCF(CN-IM) HSS(CN) Cx CSCF(CN-IM) Mm Multimedia Networks App's & Services(inc. SCP) APP APP APP APP APP(DB) APP APP APP MAP CAP UP RANAP MAP MAP UP (Routing) MAP CAP UP TCAP SCCP TCAP SCCP SCCP TCAP SCCP TCAP SCCP PPP TCAP SCCP TCAP SCCP ISUP ISUP Relay M3UA M3UA GTP-C GTP-U M3UA M3UA M3UA GTP-C GTP-U M3UA M3UA Diameter S ms Diameter ms RTP / RTCP RSVP S H.248 / MEGACO M3UA M3UA MTP-3 TCP TCP TCP MTP-2 Time Slot PCM Gf Gr WIN Gn iiu-ps Gf Gc Gn Gi D Gr Gc WIN Cx Gi Mr Mg Cx Mr Gi Mg Mc 3 3 SS No.7 isgsn(cn-ps) EIR iggsn(cn-ps) HSS(CN) CSCF(CN-IM) MRF(CN-IM) MGCF(CN-IM) T-SGW(CN-IM)

46 Technical Study Handover Scheme in Transport RAN: example Procedures to reduce the inter-rns handover delay Hard handover procedure Control Plane User Plane UE SNode B TNode B S T / MSC SGSN2 / MSC GGSN GGSN GGSN 1. Relocation Required 4. GTP tunnel setup between s ( Port# / Addr) 5. Radio Link Setup Request 6. Radio Link Setup Response 2. Forward Relocation Request 3. Relocation Request 7. Iub data transport bearer setup ( Port# / Addr) 8. Handover Command Stop DL transport and buffering, Data forwarding into T 9. Forward Handover Command 10. Forward Handover Command 11. Physical CH Reconfiguration(DCCH) 12. Detection of UE 13. Physical CH Reconfig. Complete(DCCH) Start DL transport Source UE Target Downlink Traffic Source GGSN GTP tunnel UE Target Downlink Traffic Source UE Target Uplink Traffic Source GGSN UE Target Uplink Traffic

47 Technical Study Handover Scheme in Transport RAN: example (cont d) Procedures to reduce the inter-rns handover delay Hard handover procedure (cont d) Control Plane User Plane UE SNode B TNode B S T / MSC SGSN2 / MSC GGSN GGSN GGSN 14. S Anchored Hard Handover Complete / UL and DL Transmission (Active Mode) 15. from Active Mode to Dormant Mode 16. Relocation Detect 17. Update PDP Context Request Source GTP tunnel UE Target Downlink Traffic GGSN Source GTP tunnel UE Target Uplink Traffic GGSN 17. Update PDP Context Response 18. Relocation Complete 19. Forward Relocation Complete Source GTP tunnel Target Source GTP tunnel Target 20. Release Related Links UE Downlink Traffic UE Uplink Traffic

48 Technical Study Handover Scheme in Transport RAN: example (cont d) Procedures to reduce the inter-rns handover delay Soft handover procedure Control Plane User Plane UE SNode B TNode B S T / MSC SGSN2 / MSC GGSN GGSN GGSN Start UL data receiving 1. Relocation Required 2. Forward Relocation Request 3. Relocation Request 4. GTP tunnel setup between s ( Port# / Addr) 5. New Radio Link Setup Request 6. Radio Link Setup Request 7. Radio Link Setup Response 8. New Radio Link Setup Response 9. Iub data transport bearer setup ( Port# / Addr) 10. Handover Command 11. Forward Handover Command 12. Forward Handover Command 13. DL Synchronization(DCH-FP) 14. UL Synchronization(DCH-FP) Start DL data transmitting Source Source UE GGSN GTP tunnel UE Target Downlink Traffic Target DL Sel. Downlink Traffic UL Sel. Source Source UE GGSN GTP tunnel UE Target Uplink Traffic Target Uplink Traffic

49 Technical Study Handover Scheme in Transport RAN: example (cont d) Procedures to reduce the inter-rns handover delay Soft handover procedure (cont d) Control Plane User Plane UE SNode B TNode B S T / MSC SGSN2 / MSC GGSN GGSN GGSN 15. S Anchored Active Mode 16. Active Setup Update(DCCH) 17. Active Setup Update(DCCH) Complete Dormant Mode 18. Relocation Detect 19. Update PDP Context Request Source GTP tunnel Target Downlink Traffic UE GGSN Source GTP tunnel UE Target Uplink Traffic GGSN 19. Update PDP Context Response 20. Relocation Complete 21. Forward Relocation Complete Source GTP tunnel Target Source GTP tunnel Target 22. Release Related Links UE Downlink Traffic UE Uplink Traffic

50 Conclusion There are many technical problems to be solved for RAN evolution Transport in UTRAN seems to be applied to 3.5G mobile comm. systems in Korea Open RAN(or Virtual RAN) seems to be an influential solution of 4G mobile comm. systems

51 References 3GPP TSG RAN TR , Transport in UTRAN Work Task Technical Report, V1.5.0, Dec MWIF Technical Report MTR-007, OpenRAN Architecture in 3 rd Generation Mobile Systems, V1.0.0, Sep. 4, MWIF Technical Report MTR-006, in the RAN as a Transport Option in 3 rd Generation Mobile Systems, V2.0.0, June 18, GPP TSG RAN W010001, based RAN Architecture, Feb. 5-6, GPP TSG RAN RPW010007, UTRAN Evolution, Ericsson, Feb GPP TSG RAN RPW Status of -Transport in UTRAN Work Item, Alcatel, Feb based UTRAN, Nortel Networks White Paper, Radio Access Network, Nokia s White Paper, 2000.