22 November 2005 Interactive Mobile TV: Group and Resource Management Haitham Cruickshank University of Surrey

1. 22 November 2005 Interactive Mobile TV: Group and Resource Management Haitham Cruickshank University of Surrey

2. Introduction • Multicast concept attracts growing attentions from mobile operators due to its capability of efficient service delivering: • Unlike unicast in which data are send to individual receivers, in multicast one copy of data is transmitted from source to multiple receivers. • Unlike broadcast (such as TV service), multicast distribution focused on group services. • Interworking of multicast-enabled networks is an interesting solution for Beyond 3G systems. • Examples of multicast services: • Audio and video streaming: such as on demand video and web TV/radio • Content delivery: such as electronic newspaper and notification system for sport news, up-to-date business information e.g. stock rates • Multiplayer games

3. UMTS Core DVB Distribution Network WLAN Core U: UMTS D:DVB W:WLAN U/D/W U/W U/D/W U/D U Challenges for Multicast User Services Content Provider External PDN / Internet DVB-T/H SRAN UTRAN WLAN AP (W) (U) (D) (D) (U)

4. Requirements for Successful Interworking • Advanced resource management and session management functionality to achieve desired multicast delivery coordination. • Mechanism that allow: • Selection of suitable delivery networks • Selection of appropriate service flows • Dynamically act on network conditions, e.g. load balancing • Awareness of interested receivers and their heterogeneity expressed by receiver context information. • Scalable mechanisms for network initiated: • Multicast bearer establishment and release • Vertical network handover for groups of receivers • Flow handover for groups of receivers

5. Resource Management Conceptsfor Interworking Networks

6. Resource Management – Objectives • Provide efficient multicast services delivery in a heterogeneous infrastructure comprising multicast-enabled wireless networks. • Provide efficient multicast services to heterogeneous receivers with various QoS capabilities and network interfaces. • To maximize “profit” for the network operator,while respecting the user’s preference (e.g. acceptable level of delay and QoS).

7. Resource Management - mechanisms • Service Scheduling: • Batch multiple requests for the same content into a group for a specific batching duration and then serve them over one common channel • Dynamic Access Network Selection: • Select the suitable access network and transmission QoS, which satisfies the user’s QoS requirements whilst offering the highest “profit” for the service provisioning

8. Resource Management Architecture Home Network Content request RM MSS Other cooperative networks NS/QoSA RM 3 RM 2 RM 1 Selected access network and QoS RCC GM LM service profile user profile RM: resource manager MSS: multicast service scheduling NS: network selection QoSA: QoS adaptation RCC: resource cost calculation GM: group manager LM: local monitor

9. Service Scheduling Signalling RM NS& QoSA GM ISS User requests Scheduling request (content and user profiles) Service scheduling Construct content delivery request Content delivery request (content and user profiles)

10. cooperating network providers Network Selection Signalling home network provider LM NS& QoSA RCC LM RCC RCC LM RCC LM Content delivery request Require network status Require network status Network selection and QoS adaptation Content delivery reply Network resources reservation and configuration for contents delivery

11. Group Management Conceptsfor Interworking Networks

12. Group Management - Objectives • Assist resource management by aggregating useful context information of interested receivers of a multicast user service. • Provide mechanisms to implement resource management decisions efficiently by: • Network initiated multicast bearer establishment/release • Network initiated vertical network handover for groups of receivers • Flow handover for groups of receivers • Scalable delivery of interworking signalling to large receiver groups.

13. Application Multicast Middleware UDP IGMP IP Group Management Architecture User side Network side GMs in cooperating networks Group manager (GM) Signalling CH SCF IGMII GMMF NMF Group Subscription, e.g. via HTTP IIGI Device Presence Service Network entities Resource Management Group Manager Functional Blocks: SCF: Session Control Function GMMF: Group Membership Management Function NMF: Network Management Function Interfaces: MSC: Multicast Signalling Channel IGMII: Interworking GM Interaction Interface IGII : Interworking Internal Gateway Interface

14. Multicast Signalling Channel • Motivation • Reduce signalling cost - efficient delivery of control signalling for required interworking to a large group of receivers • Principles • Instead of sending separate message to every receiver, control signalling is delivered to a group via a multicast signalling channel (MSCH) • Each user for a multicast user service subscribes to the IoN-MSCH for the duration of a session • Novel mechanism for efficient receiver subset addressing of receivers on the IoN-MSCH to minimise required signalling load: • Based on context information receivers have in common

15. Signalling Example: Session Setup Access Router Group Manager UE UE GMMF SCF RM Service Announcement/Discovery Group Subscription Scheduling and network selection IGMP join (MSC) Establish control plane ESTABLISH (IP Multicast Address, Network) IGMP join (IP Multicast Address) Establish user plane IGMP join (IP Multicast Address)

16. Signalling Example: Vertical Handover AR old AR new Group Manager UE UE GMMF SCF RM Load balancing decision MIGRATE (IP Multicast Address, new Network) IGMP join (IP Multicast Address) Switch user plane IGMP leave (IP Multicast Address)

17. Multicast Middleware (on user terminal) • Provides transparently a seamless multicast socket service to application. • On group subscription, it starts listening to a multicast signalling channel to receive control information from group manager. • Manages multicast session over terminal interfaces as requested by GM: • Establishment, release, migration of multicast bearers by remote subscription approach • Flow mobility • Forwards incoming data flows to application.

18. Not Just Concepts:Implementation Demonstration

19. What is required from the network to perform interworking ?

20. Implementation Demonstration: Scheduling and Network Selection • Each group membership subscription triggers scheduling function: • Scheduling either size- or time-based • When threshold is reached Network Selection is invoked • GMMF provides Network Selection with user group and relevant context information. • Network Selection algorithm selects appropriate QoS and network for each user in the group. • Network Selection notifies Session Control Function in group manager to initiate session establishment.

21. Implementation Demonstration : Session Control Signalling • Session Control Function (SCF) determines subgroups based on selected networks and QoS. • Extracts common context information for receivers of each subgroup and creates addressing expression uniquely identifying each subgroup. • Sends a control message for establishment/release for each subgroup via the Interworking-MSCH for the multicast user service

22. What is required from the terminal to perform interworking ?

23. Implementation Demonstration : Bearer Setup on Receiver • Multicast middleware in receiver obtains control message via interworking-MSCH. • Middleware evaluates addressing expression: • it joins the identified multicast group on the specified network interface. • Incoming multicast session data is forwarded by the middleware to the application.

24. Implementation Demonstration : Multicast Middleware • Middleware for session layer functionality • Based on TESLA toolkit (same as Migrate) • Dynamic library interposition principle • Code complexity ~ 2000 LoC (Lines of Code) Application Multicast Middleware Tesla C-library/OS

25. Middleware: Bearer Establishment - 1 1, Gets IP multicast address/port of Interworking-MSCH via announcement 2. Opens and binds socket Application Multicast Middleware (MM) C-library/OS 3. Multicast middleware opens real socket using provided IP multicast address/port 4. Starts listening to commands from group manager

26. Middleware: Bearer Establishment - 2 7. Starts forwarding incoming data to application Application Interworking-MM C-library/OS 6. Establishes multicast socket on Identified interface for data plane 5. Receives establish request (IP Multicast address/port/network)

27. Middleware: Vertical Handover - 1 3. Still forward data from old socket until data from new one arrives Application Interworking-MM C-library/OS 1. Receives migrate request Old and new (IP Multicast address/port/network) 2. Establishes new multicast socket on Identified interface for new data plane

28. Middleware: Vertical Handover - 2 6. Application receives data from new socket Application Interworking-MM C-library/OS 5. Old data plane is released 4. New data arrives

29. What is the complexity to perform interworking ?

30. University of Surrey: Wireless Network Testbed

31. Implementation Demonstration: Network Architecture

32. Implementation Demonstration: Network Equipment • Network infrastructure • 2 Cisco routers (2600 series) • 1 GigabitEthernet Layer3 switch • Layer 2 switches • 1 WLAN access point • Servers • Interworking gateway (GM/RM) • Streaming servers • Web server • Clients • 3 Laptops with Ethernet/WLAN card • Fedora Core 3 Linux

33. Implementation Demonstration: Gateway Implementation • Implementation language C++ and QT library: • Portable to any platform • Code complexity ~ 8000 LoC • Features: • Multithreaded group management server • Service Manager for service creation • Each service provides: • its own grouping, and up to 2 different service flows • scheduling (size and timeout based) • network selection function (by the RM function) • its own Interworking-MSCH (messages XML based) • User context information data base and browser

34. Other components • Webserver • Apache 2 • HTML fronted for user subscription • Python script as subscription backend to group manager • Streaming Server • Video LAN Client (VLC) as video server • Currently streaming UDP however RTP also possible • User request simulation • Python script

35. Conclusions

36. Resource and Group Management: Conclusions • In interworked heterogeneous wireless networks: • Resource management focuses on service scheduling, and network selection • Group management focuses on aggregation of receiver context information to support RM in its decision making • Close interaction between resource and group management during set-up and handover. • Combined interworking and multicast is a promising solution to extended services in existing wireless networks.

37. Thank you !