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  1. 1. LTE Network and Radio Planning Design Ali Al Sarraf Ali Al Sarraf 1
  2. 2. • • • • • LTE Introduction and Architecture Overview. The LTE Radio Interface and Channels. LTE Link Budgets. Capacity Planning Principles. CPE Testing Procedure. Ali Al Sarraf Course Outline 2
  3. 3. Ali Al Sarraf LTE Introduction and Architecture Overview 3
  4. 4. • • • • • • • • • • • • • • • • • • • • 3GPP (3rd Generation Partnership Project) GSM (Global System For Mobile Communication) EDGE (Enhanced Data rates for GSM Evolution) HSDPA (High Speed Downlink Packet Access) HSUPA (High Speed Uplink Packet Access) MBMS (Multimedia Broadcast-Multicast Services) LTE (Long Term Evolution) SMS (Short Message Service) CS (Circuit Switch) MSC (Mobile Switching Centers) GMSC (Gateway Mobile Switching Center) PSTN (Public Switched Telephone Network) HLR (Home Location Register) GPRS (General Packet Radio Service) PS (Packet Switched) SGSN (Serving GPRS Support Nodes) GGSN (Gateway GPRS Support Nodes) GTP (GPRS Tunneling Protocol) IMS (IP Multimedia Subsystem) SIP (Session Initiation Protocol) Ali Al Sarraf Important Shortcut 4
  5. 5. • • • • • • • • • • • • • • • • • • UE (User Equipment) MIMO (Multiple Input Multiple Output) E-UTRAN (Evolved Universal Terrestrial Radio Access Network) EPC (Evolved Packet Core) eNodeB (Evolved Node B) S-GW (Serving Gateway) P-GW (Packet Data Network Gateway) MME (Mobility Management Entity) RRM (Radio Resource Management) QoS (Quality of Serving) HSS (Home Subscriber Server) SAE (System Architecture Evolution) EPDG ( Evolved Packet Data Gateway) MIP (Mobile IP) PMIP (Proxy Mobile IP) AAA Server (Authentication, Authorization and Accounting) SON (Self Organizing Networks) EPS (Evolved Packet System) Ali Al Sarraf Important Shortcut 5
  6. 6. Ali Al Sarraf Global Broadband Subscribers 6
  7. 7. • • • • • • Access-independent Internet applications. Web 2.0. Streaming services. Interactive remote gaming. Quadruple play. Mobile office. Ali Al Sarraf Typical Next Generation Services 7
  8. 8. • • • • • • • • High peak user data rates. High average data throughput rates. Low latency. Guaranteed radio coverage. Individual quality of service (QoS). Service continuity between access networks. Single sign-on to all network access. Competitive prices, flat-rate fees. Ali Al Sarraf Typical Enablers for Next Generation Services 8
  9. 9. • The next child in a long generation of 3GPP standards LTE “Long Term Evolution” GSM WCDMA GPRS HSDPA EDGE HSUPA E-EDGE HSPA+ LTE 4G LTE Advanced Ali Al Sarraf What is LTE ? 9
  10. 10. What Is 3GPP: Ali Al Sarraf • The 3rd Generation partnership project ( 3GPP) is a collaboration that was established in December 1998. The collaboration agreement brings together a number of telecommunications standards bodies which are known as “Organizational partners”. The current Organizational partners from Asia, Europe, and North America. 10
  11. 11. • To produce technical specifications and technical reports for a 3G Mobile system based on evolved GSM core networks and radio access technologies that they support. • The scope was amended to include the maintenance and development of the global system for mobile communication (GSM) technical specifications and technical reports including evolved radio access technologies (e.g. General Packet Radio Service (GPRS) and Enhanced Rates for Evolution (EDGE)). Ali Al Sarraf 3GPP Scope 11
  12. 12. • Release 99: defined the original UMTS system, supporting circuit voice services as well as theoretical peak date rates of up to 2 Mbps. • Release 4: defined a bearer-independent circuit-switched architecture, separating switched into gateways and controllers. • Release 5: defined High Speed Downlink Packet Access (HSDPA), which boosted packet data rates to 14 Mbps on the downlink. Release 5 also completed the design of IMS. • Release 6: Increased data rated to more than 5 Mbps on the uplink with High Speed Packet Access (HSUPA) and introduced support for multimedia broadcast/multicast services (MBMS). • Release 7: provided further enhancement to HSDPA and HSUPA, called HSPA+, support for higher-order modulation and ( MIMO) antenna systems offers a significant increase in data rates, potentially up to 42 Mbps. • Release 8: defined the long term Evolution (LTE) systems, starting the transition to 4G technology. Ali Al Sarraf 3GPP Releases 12
  13. 13. • The global system of mobile communication (GSM) is the most popular 2G standard for mobile communication. It is estimated that over 80% of the global market uses GSM. Standardized in two phases in 1992-1995, GSM initially supported circuitswitched voice services, circuit-switched data at 2.4,4.8 and 9.6 Kbps, and introduced Short Message Service (SMS). • GSM release 96 introduced higher speed circuit-switched data rates. • The 2G GSM network uses a 200 KHz air interface, and a Circuit Switched (CS) domain for digital voice/signaling . The CS domain consists of one or more Mobile Switching Centers (MSC) and Telephone Network (PSTN). • The Home Location Register (HLR) contains the subscriber records, including authentication information and services associated with a subscriber. Ali Al Sarraf Global System for Mobile Communication (GSM) CS Domain RAN BTS BSC MSC GMSC PSTN 200 KHz 13 HLR, AUC
  14. 14. General Packet Radio Service (GPRS) SGSN MSC BTS GMSC PSTN BSC 200 KHz • Introduced in GSM release 97, General Packet Radio Service (GPRS) is a 2.5G packet data network that shares the radio access network with GSM but has a separate Packet Switch (PS) core network. • In a GSM/GPRS network, data traffic is forwarded through the PS domain, while voice and SMS traffic goes through the CS domain. • GPRS consists of Serving GPRS Support Nodes (SGSN) and Gateway GPRS Nodes (GGSN). SGSNs and GGSNs support IP mobility tunnels based on the GPRS Tunneling Protocol (GTP),GPRS has theoretical data rates between 56 and 114 Kbps. Ali Al Sarraf RAN SGSN External Data Network 14
  15. 15. Enhanced Data Rates For GSM Evolution (EDGE) Ali Al Sarraf • Introduced in release 99, Enhanced Data Rates For GSM Evolution (EDGE) provides coding and modulation improvements to GPRS that support minimum 3G data rates from 236 Kbps to 473 Kbps depending on coding and modulation techniques used. EDGE does not introduce any changes to the network other than coding and modulation enhancements to the air interface to increase data speed. PS Domain GGSN SGSN RAN BTS External Data Network GMSC PSTN HLR AuC BSC MSC CS Domain 15
  16. 16. • UMTS release 5 (R5) introduced big changes to the UMTS network. Beginning in R5, all traffic is transported via the PS domain using IP. Because all traffic is now forwarded by the PS domain, release 5 removes the circuit switch domain from the network architecture. • Critical circuit switched functions, such as voice call setup, interconnecting with PSTN, and so on, are preformed by the IP Multimedia Subsystem (IMS). An R5 compliant UE must communicate with IMS using Session Initiation Protocol (SIP) signaling, and generate and receive voice over IP traffic within the subscriber device. • UMTS R5 also introduced High Speed Downlink Packet Access (HSDPA), and it is increased peak downlink throughput to 14.4 Mbps. SGSN Ali Al Sarraf UMTS Release 5 IMS GGSN Voice, Data over IP External Data Network HSS RAN 5 MHz Node B RNC PSTN MSC Server 16 BICC WCDMA MGW MGW PSTN
  17. 17. • With the introduction of High Speed Uplink Packet Access (HSUPA), UMTS release 6 increased the peak uplink speed to 5.76 Mbps. UMTS R6 also enhanced IMS, and introduced Multimedia Broadcast Multicast Services (MBMS) to support broadcast services such as Mobile TV. • MBMS offers broadcast and/or multicast, unidirectional, point to multipoint , multimedia flows. • Broadcast and multicast are two completely different services. A broadcast service is transmitted to all user devices which have the service activated in their equipment. A service provider does not attempt to charge for limit the broadcast transmission. • In contrast, a multicast service is subscription-based. A UE must have subscribed to the service and explicitly joined the multicast group to receive the multicast transmission. A service provider may track, control, and charge for multicast transmission. • Examples of possible MBMS applications include audio/video streaming, audio/video downloading, file downloading, and text/image distribution. Ali Al Sarraf UMTS Release 6 17
  18. 18. UMTS Release 6 MBMS RAN 5 MHz WCDMA HSUPA Node B IMS RNC HSS External Data Network Ali Al Sarraf PS Domain SGSN GGSN PSTN 18
  19. 19. UMTS Release 7 MBMS PS Domain SGSN GGSN RAN 5 MHz WCDMA HSPA+ MIMO Node B Ali Al Sarraf • Along with enhancing IMS, UMTS Release 7 introduced Multiple Input Multiple Output (MIMO) antenna technology and High Speed Packet Access+ (HSPA+). MIMO antenna systems significantly improve radio network throughput and coverage. HSPA+ with 2X2 MIMO increases uplink speeds to 11.5 Mbps and downlink speeds to 22Mbps. IMS RNC HSS External Data Network PSTN 19
  20. 20. • UMTS release 8 introduce the Evolved Universal Terrestrial Radio Access Network (E-UTRAN) And the Evolved Packet Core (EPC). • To reduce latency, the E-UTRAN collapsed the UMTS Node B and RNC functionality into the evolved NodeB ( eNodeB). In addition to 5Mhz, the EUTRAN radio access network supports 1.4,3,10,15 and 20MHz Channels. • R8 with 2X2 MIMO and 64 QAM modulation increases UL speeds to 23 Mbps, and DL Speeds to 42 Mbps. • In the evolved packet core, the SGSN and GGSN are Replaced by the Serving Gateway (S-GW) and Packet Data Network Gateway (P-GW). The Mobility Management Entity (MME) manages UE mobility and paging functions. Ali Al Sarraf UMTS Release 8 (LTE) 20
  21. 21. UMTS Release 8 (LTE) MBMS HSS MME RAN Node B 1.4 – 20 MHz S-GW P-GW IMS PSTN Ali Al Sarraf Evolved Packet Core External data network Evolved UTRAN 21
  22. 22. • The UMTS release 8 architecture consists of the EPC, E-UTRAN, and user entities (UEs). • The Evolved Universal Terrestrial Access Network (E-UTRAN) is defined by UMTS Release 8 as Long Term Evolution (LTE). • System Architecture Evolution (SAE) defines the Evolved Packet Core (EPC). The EPC is an all IP, packet switched network. • The Evolved Packet System (EPS) includes the EPC, LTE, and the user terminals called User Equipment (UE). MME S-GW Ali Al Sarraf EPS Architecture P-GW 22 UE eNodeB eNodeB UE
  23. 23. Evolved UMTS Radio Access Network (E-UTRAN) S1 MME/S-GW S1 S1 Ali Al Sarraf MME/S-GW S1 X2 E-UTRAN X2 X2 23
  24. 24. • Radio Recourse Management (RRM): like radio bearer control and radio admission control. • IP header compression and encryption od the users data stream. • Uplink/Downlink radio resource allocation in both the pulink and downlink. • Transfer of paging messages over the air. • Transfer of broadcast information over the air. • Selection of the MME when attached to network. • Handover management. MME S-GW P-GW Ali Al Sarraf eNodeB Functions External Data Network 24 eNodeB
  25. 25. • Evolved UMTS Radio Access Network (E-UTRAN) contains a single elements known as the evolved Node B (eNB). The eNB supports all the user plane and control plane protocols to enable communication with the UE. It also supports radio resource management, admission control, scheduling , uplink QoS enforcement, cell broadcast, encryption and compression /decompression of user data. • The eNB is connected to the core network on the S1 interface. The S1 interface allows the eNB to communicate with Mobility Management Entity (MME) via the S1-MME a many to many relationship between eNB and SGW/MME. • The eNB are also networked together using the X2 interface, the X2 interface is based on the same set of protocols as the S1 and is primarily in place to allow user plane tunneling of packets during handover to minimize packet loss. Ali Al Sarraf eNodeB Functions 25
  26. 26. X2 Interface Multi-cell RRM (Radio Recourse Management) Handover functions: handover cancellation. Uplink load Management. Tunneling of user packets. Ali Al Sarraf • • • • X2 eNodeB eNodeB X2 X2 eNodeB Evolved -UTRAN 26
  27. 27. User Equipment Ali Al Sarraf The User Equipment (UE) must preform the following functions: • Signal network entry and other state changes. • Report its tracking area location while in idle mode. • Request UL grants to transmit data while in active mode. MME S-GW P-GW External Data Network 27 eNodeB
  28. 28. The Evolved Packet Core network is an all IP, packet switched network. The EPC consists of: • Mobility Management Entity (MME) : key control node for the LTE access network. • Serving Gateway (S-GW) : routes and forwards data packets. • Packet Data Network Gateway (P-GW) : provides connectivity to external packet data networks. External Data P-GW Network EPC MME Ali Al Sarraf EPC Components S-GW 28 eNodeB
  29. 29. Mobility Management Entity (MME) Idle mode UE tracking and paging. Bearer activation/deactivation. Chooses S-GW for UE. Authentication with HSS. Assigns temporary identity to UE. MME S-GW Ali Al Sarraf • • • • • P-GW External Data Network 29 eNodeB
  30. 30. Mobility Management Entity (MME) The primary signaling node in the EPC. Managing and storing UE context. Idle-state mobility control. Distributing paging (Communicate with UE when the network does not know the cell location for UE) massages to eNBs. • Security control. • Roaming , Authentications. • Admission control and communication with the home HSS on the S6a interface. MME S-GW P-GW Ali Al Sarraf • • • • External Data Network 30 eNodeB
  31. 31. Serving Gateway • • • Internet S5 Interface Ali Al Sarraf • • There are two Gateways in the EPC: One facing towards the E-UTRAN (the S-GW). One facing towards the external packet data network (the P-GW). S-GW functions: Anchoring the user plane for inter-eNB handover. Anchoring the user plane for inter -3GPP mobility (LTE with 3G). Packet routing and forwarding. S1 Interface eNodeB 31 X2 Interface
  32. 32. • • • • • • P-GW functions: Provide connectivity to the PDN and Packet routing for the UE. Allocates IP addresses to the UE. The entry and exit point for UE connectivity with external data networks. Accounting and QoS. Anchor the user plan during MME/SGW handover and during 3GPP-to Non3GPP handover. Ali Al Sarraf Packet Data Network Gateway 32
  33. 33. • The HSS is a user database that stores subscription-related information to support other call control and session management entities. • It’s a storehouse for user identification, numbering , service profiles and location. • It is mainly involved in user authentications and authorization. • Generates security-related information. Ali Al Sarraf Home Subscriber Server (HSS) 33
  34. 34. LTE SAE Reference Points IMS SGI S2a P-GW S3 MME S11 Ali Al Sarraf SGI UMTS Non-3GPP access Internet S5 S-GW S1-MME S1-U X2 34 eNodeB eNodeB
  35. 35. S1 Interface Ali Al Sarraf • • • • S1 Functionalities are split into C-Plane and U-plane Functionalities : The S1 Control Plane: Delivering a signaling between the eNB and MME. Handover signaling procedure. Paging procedure. NAS transport procedure. The S1 User plane: • Responsible for delivering user data between the eNB and S-GW. MME S-GW S1-MME P-GW SGi S1-U Uu 35 Uu UE eNodeB X2 eNodeB UE
  36. 36. • S2a/b: it provides the user plane with related control and mobility support between a trusted/ not-trusted non-3GPP Ip access and the SAE anchor. • S2a ( Between Trusted Non 3G and LTE P-GW) • S2b( Between Non- Trusted Non 3G and LTE P-GW) • S3: it enables user and bearer information exchange for inter 3GPP access system mobility in idle and/or active state. It is based on Gn reference point defined between SGSNs. • SGI: it is the reference point between the inter AS anchor and the packet data network, packet data network may be an operator external public or private packet data network or an intra operator packet data network. Ali Al Sarraf LTE Reference Points 36
  37. 37. Interworking with trusted 3GPP & Non 3GPP Networks • Trusted Non-3GPP Access • Non-3GPP IP access describes access to the EPC by technologies not defined by 3GPP. Non-3GPP access technologies include WiFi, WiMAX, fixed access such as cable or DSL, and so on. System Architecture Evolution (SAE) describes trusted and untrusted non-3GPP IP access. • The individual carrier must decide if a non-3GPP network is trusted or untrusted. This is a business decision and dies not depend on the access network technology. Ali Al Sarraf • Serving GPRS Support Node (SGSN) • In 2G and 3G systems, the Serving GPRS Support Node (SGSN) is responsible for the delivery of data packets to and from UEs within its geographical service area. The SGSN provides the interfaces between the MME and S-GW in the EPC. 37
  38. 38. Interworking with trusted 3GPP & Non 3GPP Networks PCRF SGSN S4, S12 GERAN, UTRAN HSS MME S-SW P-GW Ali Al Sarraf S3 S2a/S2c UE eNodeB Trusted non-3GPP Access 38
  39. 39. Evolved Packet Data Gateway (ePDG) • The evolved Packet Data Gateway (ePDG) connects the LTE network to an untrusted, non-3GPP network. To access the LTE network, the non-3GPP subscriber must establish an IP Security (IPSec) tunnel via the ePDG. The ePDG is the encapsulation- de capsulation point for Mobile IP / Proxy Mobile IP (MIP/PMIP). • The ePDG also authenticates, authorizes, and enforces QoS policies in conjunction with the 3GPP AAA server. 3GPP AAA Server • The 3GPP AAA server provides authentication, authorization, and accounting services for untrusted non-3GPP IP access. Ali Al Sarraf Interworking with Untrusted 3GPP networks 39
  40. 40. Interworking with Untrusted 3GPP networks HSS MME S-SW Ali Al Sarraf PCRF P-GW S2a/S2c ePDG 3GPP AAA UE eNodeB UnTrusted non-3GPP Access 40
  41. 41. Two additional interfaces are specified, S3 and S4: • S3 supports the user and bearer information exchange so the SGSN and the MME during handover/cell reselection. • QoS and user context will be exchange so the target system has all the information required to re-establish the bearer on the new cell. • S3 is based on the IP GN interface designed for 2G/3G core architecture. • S4 carries the user plane data between the SGSN and the S-GW. • The S-GW play the role of the mobility anchor in inter-system exchanges, it has a very similar role to the GGSN in 2G/3G networks. • The S4 interface is also based on the Gn interface. Ali Al Sarraf Inter working with 2G/3G Networks 41
  42. 42. Trusted access (the operator owns and operates the WLAN network): • The user data sent directly to the P-GW via the IP based S2 interface. • Information relating to subscriber profiles, authentication vectors, network identity, charging and QoS information may all be provides to the WLAN access via the Ta interface. • The information is provided via the 3GPP AAA server which acts as an interworking point between the 3GPP and IETF worlds. • The main purpose of the 3GPP AAA server is to allow end to end interaction, such as authentications to take place using 3GPP credentials stored in the HSS via the Wx interface. Non-trusted case (a corporate entity has its own WLAN network): • The ePDG (evolved Packet Data Gateway) element carried all the traffic from the WLAN via a secure tunnel (IPSec) over the Wn interface. • The Wn interface allows the user related data from the HSS via the 3GPP AAA server, to be exchanged, ensuring proper tunneling and encryption between the user terminal and the P-GW. Ali Al Sarraf NON-3GPP Access 42
  43. 43. • HeNB deployed as small E-UTRAN cells in domestic, small office etc. • HeNB interconnects with the evolved Packet Core, over a fixed broadband access network. • Support for full mobility into and out of a HeNB Coverage including service continuity where applicable. • Operators and owners of HeNB will be able to control access to the resources provided. Ali Al Sarraf LTE Femto Cells 43
  44. 44. • Femto Functions: • HNB and HeNB deployed as small UTRA and E-UTRAN cells, respectively, in domestic, small office and similar environments. • The HNB and HeNB interconnects with the 3G core and evolved Packet Core, respectively, over a fixed broadband access network. • Support for full mobility into and out of a HeNB coverage including service continuity where applicable. • Operators and owners of HeNB and HNB will be able to control access to the resources provided. Ali Al Sarraf Femto Cell 44
  45. 45. Handover • Source eNB configures UE measurements. • Source eNB receives UE measurement reports. • HO decision is made and target eNB is selected by the source eNB. S-GW S1-MME S1-U Source eNodeB Control plane User plane User data Ali Al Sarraf MME X2 eNodeB Target Measurements 45 UE
  46. 46. Handover • HO request sent from source eNB to target eNB. • Target eNB performs admission control and accespts the HO request. • HO Ack. Sent to source eNB from target eNB. S-GW S1-MME Ali Al Sarraf MME S1-U HO Request Source eNodeB Control plane User plane User data HO ACK. eNodeB Target Measurements 46 UE
  47. 47. Handover • HO command is sent to the UE ( RRC connection reconfiguration including the mobility control info. • Data forwarding initiated towards the target eNB. S-GW S1-MME S1-U Source eNodeB Control plane User plane User data Ali Al Sarraf MME X2 eNodeB Target HO Command 47 UE
  48. 48. Handover • UE accesses the target eNB and confirms the HO (RACH procedure is initiated and RRC connection reconfiguration complete is sent) S-GW S1-MME Source eNodeB Ali Al Sarraf MME S1-U eNodeB Target X2 HO Confirm Control plane User plane User data 48 UE
  49. 49. • • • • • • Target eNB requests EPC to switch the data path eNB MME : path switch request. MME S-GW: modify bearer request. S-GW MME: modify bearer response. MME eNB: path switch request ACK. Target eNB notifies the source eNB that UE resources can be released. MME S-GW S1-MME Source eNodeB Ali Al Sarraf Handover S1-U eNodeB Target X2 HO Confirm Control plane User plane User data UE 49
  50. 50. Handover MME S-GW S1-MME Source eNodeB Control plane User plane User data Ali Al Sarraf • Path is switched. • Source eNB finishes , forwarding packets (one completed UE context can be cleared and resources freed). • HO is complete. S1-U X2 eNodeB Target 50
  51. 51. Self Organizing Networks Automatic software management Self test. automatic neighbor relation configuration. Tracking area planning . Existing eNodeB Physical cell ID planning. Load balancing. Handover optimaisations. New eNodeB DHCP/DNS S-GW MME OSS Ali Al Sarraf • • • • • • • Configuration And performance 51
  52. 52. • The objective of the self- configuration SON functionality is to reduce the amount of human intervention in the overall installation process by providing “plug and play” functionality in the eNodeBs. • Self-Configuration of eNodeBs will reduce the amount of manual processes involved in the planning, integration and configuration of new eNodeBs. • This will result in a faster network deployment and reduced costs for the operator. Ali Al Sarraf Self Organizing Networks (SON) 52
  53. 53. SON Processing • After switching in eNB, its called Self Configuration starts. • The eNB is already physically connected with the network, but the RF is still switched off. An IP address and a connection to an O&M is assigned to the eNB. • After an authentication in the network, the eNB gets an association to the MME and S-GW, and the connections to the core (S1)and to the neighbored eNBs (X2) are established. Ig available there may be a software update. • Also the physical cell identities (PCI) for all supported cells in the eNB are assigned here, as these are required to go on air. Self configuration Ali Al Sarraf SON Processing Self Optimization 53 Self Healing Switch on RF
  54. 54. SON Processing The Self Optimization: • This stage starts by switching in the RF. • Mobiles may now connect with the cells and return feedback to improve the initial radio configuration and also to adopt the to traffic load or measured propagation conditions. • For this feedback, existing RRC measurements have been extended. Self configuration Ali Al Sarraf • After these basic setup procedures, the eNB gets the initial radio configuration. This is comprised by the initial neighbor list, the coverage and capacity related parameter configuration like transmission power, antenna tilt, and all remaining parameters for operation. These parameters are finally optimized at the next stage, the Self optimization. Self Optimization 54 Self Healing Switch on RF
  55. 55. SON Processing Self Healing: In the case of a failure, the so called Self Healing applies. In case of a hardware failure, the eNB switches to a spare part. In case of a failure was caused by a not properly running software update, the eNB reloads a former software. • When none of these remaining eNBs change their setting in order to fill the coverage gap created by the failure. Self configuration Ali Al Sarraf • • • • Self Optimization 55 Self Healing Switch on RF