計畫主持人：許蒼嶺 ( 國立 中山大學 電機工程學系 ) 授課教師 ：萬欽德 ( 國立高雄第一科技大學 電腦與通訊工程系 )

1. 教育部補助「行動寬頻尖端技術跨校教學聯盟第二期計畫--行動寬頻網路與應用--小細胞基站聯盟中心」EPC核心網路系統設計課程單元 05：Data Services in EPS 計畫主持人：許蒼嶺 (國立中山大學 電機工程學系) 授課教師：萬欽德 (國立高雄第一科技大學 電腦與通訊工程系)

2. Growing Mobile Data Traffic • Mobile data traffic is growing exponentially, caused by mobile internet offerings and improved user experience with new device types. • LTEperspective • Long term evolution perspective for 2G and 3G networks based on WCDMA/HSDPA, GSM/EDGE, TD-SCDMA, and CDMA2000 technologies. EPC核心網路系統設計

3. EPC核心網路系統設計

4. Evolution of Radio Access Technologies EPC核心網路系統設計

5. Consideration for LTE • Definition began: Nov. 2004 • 3GPP (3rd Generation Partnership Project) began a project to define the Long-Term Evolution (LTE) for Universal Mobile Telecommunications System (UMTS) cellular technology • Considerations: • Higher performance • Backwards compatible • Wide applications EPC核心網路系統設計

6. Data Services in EPS • EPS is a faster, lower latency mobile broadband solution. • Primarily with IP connectivity and data services • 1990s (on GPRS) • Wireless Access Protocol (WAP) • Low successful rates • 2000s • High Speed Packet Access (HSPA) • Indication of high demand for mobile broadband EPC核心網路系統設計

7. Global Traffic in Mobile Networks • The launch of the first “smartphone” in 2007 – the iPhone – changed everything. • Mobile Internetand application-centric ecosystem. EPC核心網路系統設計

8. IP Connectivity • Smartphones, tablets, and app stores are just the beginning of the changes that mobile broadband will deliver through data services. • Essential elements in users’ lives: • Roads • Electricity • Connectivity EPC核心網路系統設計

9. Data Services • Two aspects– • Messaging services • Short Messaging Service (SMS) - GSM • Multimedia Messaging Service (MMS) • Machine-to-Machine communication • Industrial and Corporate Uses • Big Data Analysis and Management EPC核心網路系統設計

10. Subscriptions: Fixed vs. Mobile EPC核心網路系統設計

11. Messaging Support with EPC • Using an IP-based solution (IMS-based messaging or SMS-over-IP) • Messages are sent transparently through the network from a messaging server to the client, and are treated just like any IP packet by the EPC. • Using the circuit-switched infrastructure that is normally used to deliver SMS messages over GSM and WCDMA. • Noted that LTE is a packet-only radio access EPC核心網路系統設計

12. Options for Messaging Services • The MME interacts with the MSC Server when the CS infrastructure is used. • The MSC Server is normally connected to a messaging center for delivery of SMS messages over control channels in GSM and WCDMA, and via the interaction with MME. • Messages are included in NAS signaling messages between MME and the mobile device. This solution supports only SMS text messaging. • Other types of messages (e.g., MMS) need to be based on IP. EPC核心網路系統設計

13. Machine-to-Machine (M2M) Communication • Private cars • communicating service needs • car’s position (retrieved using GPS) • receiving up-to-date traffic data for traffic guidance systems • Water or electricity meters • remote control and/or remote meter reading • Taxi cars • validating credit cards EPC核心網路系統設計

14. Machine-to-Machine (M2M) Communication (cont’d) • Street-side vending machines • communicating when goods are out of stock or when enough coins are present • Delivery cars • fleet management, including optimization of delivery routes and confirming deliveries • Ambulances • sending life-critical medicine data to the hospital prior to arrival • Surveillance cameras • home or corporate security EPC核心網路系統設計

15. M2M and Data Analysis EPC核心網路系統設計

16. 3GPP Architecture Domains The Core Network can be divided into multiple domains (Circuit Core, Packet Core, and IMS). 行動寬頻EPC核心網路與應用

17. 3GPP Architecture Domains (cont’d) The subscriber data management domainprovides coordinated subscriber information and supports roaming and mobility between and within the different domains. 行動寬頻EPC核心網路與應用

18. Domains • Circuit Core domainprovides support for circuit-switched services over GSM and WCDMA. • Packet Core domainprovides support for packet-switched services (primarily IP connectivity) over GSM, WCDMA, and HSPA. • The IMS domainprovides support for multimedia sessions based on SIP (Session Initiation Protocol), and utilizes the IP connectivity provided by the functions in the Packet Core domain. 行動寬頻EPC核心網路與應用

19. 行動寬頻EPC核心網路與應用

20. Logical and Physical Interfaces • The physical implementation of a particular interface may not run directly between two nodes. • it may be routed via another physical site. • Example: • X2 interface, connecting two eNodeBs, may physically be routed from eNodeB A together with the S1 interface (which connects an eNodeB to an MME in the core network) to a site in the network with core network equipment. From this site, it would be routed back onto the radio access and finally to eNodeB B. 行動寬頻EPC核心網路與應用

21. Logical and Physical InterfacesAn Example: 行動寬頻EPC核心網路與應用

22. Basic IP Connectivity over LTE Access • To optimize the handling of the user data traffic itself, through designing a “flat” architecture. • To separate the handling of the control signaling (shown as dotted lines) from the user data traffic 行動寬頻EPC核心網路與應用

23. Separation of Control Signalingfrom User Data Traffic • Factors: • The need to allow independent scaling of control and user plane functions • Control data signaling tends to scale with the number of users • User data volumes may scale more depending on new servicesand applications, as well as the capabilities in terms of the device (screen size, supported codecs, etc.). 行動寬頻EPC核心網路與應用

24. Separation of Control Signalingfrom User Data Traffic • Factors (continued): • Flexibility in terms of network deployment • the freedom of locating infrastructure equipment handling user data functions in a more distributed way in the networks • allowing for a centralized deployment of the equipment handling the control signaling • Minimization of delaysin real-time services such as voice or gaming • Optimized operational costs(having the functions at separate physical locations in the network) 行動寬頻EPC核心網路與應用

25. eNodeBs in the Network • In a reasonably sized network scenario, there may be several thousandeNodeBsin the network. • Many of these eNodeBsmay be interconnected via the X2 interface in order to allow for efficient handovers. • All eNodeBsare connected to at least one MME (Mobility Management Entity) over the S1-MME logical interface. 行動寬頻EPC核心網路與應用

26. Mobility Management Entity • Handling all LTE-related control plane signaling • Mobility and security functions for devices and terminals • Managing all terminals that are in idle mode Support for Tracking Area management and paging • Relying on the existence of subscription-related user data for all users trying to establish IP connectivity over the LTE RAN. • For this purpose, the MME is connected to the HSS (the Home Subscriber Server) over the S6a interface. 行動寬頻EPC核心網路與應用

27. HSS (Home Subscriber Server) • HSS manages user data and related user management logic for users accessing over the LTE RAN • Subscription data includes credentials for authentication and access authorization • HSS supports mobility management within LTE as well as between LTE and other access networks 行動寬頻EPC核心網路與應用

28. Serving GW and PDN GW • The user data payload (the IP packets) flowing to and from the mobile devices are handled by two logical nodes: • Serving Gateway (Serving GW) • PDN Gateway (Packet Data Network GW) • The Serving GW and PDN GW are connected over an interface • Interface S5 (if the user is not roaming, i.e. the user is attached to the home network) • Interface S8 (if the user is roaming, i.e. attached to a visited LTE network) 行動寬頻EPC核心網路與應用

29. Serving GW • The Serving GW terminates the S1-U user plane interface towards the base stations (eNodeBs) • The Serving GW constitutes the anchor point for intra-LTE mobility, as well as (optionally) for mobility between GSM/GPRS, WCDMA/HSPA and LTE. • The Serving GW buffers downlink IP packets destined for terminals that happen to be in idle mode. • For roaming users, the Serving GW always resides in the visited network, and supports accounting functions for inter-operator charging and billing settlements. 行動寬頻EPC核心網路與應用

30. PDN GW • The PDN GW is the point of interconnection to external IP networks through the SGi interface. • Functionality: • IP address allocation, charging, packet filtering, and policy-based control of user-specific IP flows • supporting QoS for end-user IP services • handles the packet bearer operations • supports transport-level QoS(by marking IP packets with appropriate DiffServ code points based on the parameters associated with the corresponding packet bearer) 行動寬頻EPC核心網路與應用

31. Split of S-GW and PDN-GW (1/4) • S8 interface connecting the Serving GW in the visited network and the PDN GW in the home network. 行動寬頻EPC核心網路與應用

32. Split of S-GW and PDN-GW (2/4) • When a user wants to connect to more than one external data network at the same time, and not all of these can be served from the same PDN GW. All user data relating to the specific user will then always pass the same Serving GW, but more than one PDN GW. 行動寬頻EPC核心網路與應用

33. Split of S-GW and PDN-GW (3/4) • When a user moves between two LTE radio base stations that does not belong to the same service area, the Serving GW needs to be changed, while the PDN GW will be retained in order not to break the IP connectivity. 行動寬頻EPC核心網路與應用

34. Split of S-GW and PDN-GW (4/4) • When an operator’s deployment scenario causes the operator to have their PDN GWs in a central location whereas the Serving GWs are distributed closer to the LTE radio base stations (eNodeBs). 行動寬頻EPC核心網路與應用

35. S11 interface • Control plane signaling between the MME and the Serving GW • One of the key interfaces in the EPC architecture. • Establishing IP connectivity for LTE users through connecting Gateways and radio base stations • Providing support for mobilitywhen users and their devices move between LTE radio base stations 行動寬頻EPC核心網路與應用

36. Advanced Functionality for LTE Access • Some more interfaces • Some additional advanced features targeting the control of end-user IP flows • IP flow: a web browsing session or a TV stream • Three new logical nodes: PCRF, the OCS, and the OFCS • PCC (Policy and Charging Control) • Designed to enable flow-based charging • Online credit control • Policy control: support for service authorization and QoSmanagement 行動寬頻EPC核心網路與應用

37. Advanced Functionality for LTE Access (cont’d) • How the data will be charged for or what QoS will be awarded to the service? • The PCRF contains policy control decisions and flow-based charging control functionalities. • Both the charging and the policy control functions rely on all IP flows being classified (in the PDN GW/ Serving GW) using unique packet filters that operate in real time on the IP data flows. 行動寬頻EPC核心網路與應用

38. 行動寬頻EPC核心網路與應用