1 End-to-End QoS Provisioning in UMTS networks -Midterm Presentation Group 995 Haibo Wang Devendra Prasad Supervisors: Hans-Peter Schwefel Oumer Teyeb

2 Presentation outline 1. Motivation 2. Background 3. Problem Delimitation 4. Preliminary Simulation 5. Proposed QoS algorithms 6. Future work

3 What is End2End QoS? Quality of Service Quality of Service is a set of requirements to be met by the network while transporting a traffic flow. Only the QoS perceived by end-user matters [1] Only the QoS perceived by end-user matters [1] 1.Motivation

4 QoS provision mechanisms and QoS control mechanisms [2]: QoS provision mechanisms include parameters mapping, admission and resource reservations schemes. QoS provision mechanisms include parameters mapping, admission and resource reservations schemes. QoS control mechanisms consist of traffic shaping, scheduling, policing and control. QoS control mechanisms consist of traffic shaping, scheduling, policing and control. QoS mechanisms Delay Delay Jitter Jitter Loss Rate Loss Rate Throughput Throughput These parameters reflect the traffic flow through the network. These parameters reflect the traffic flow through the network. End2End QoS Parameters

5 Offered QoS through SLA QoS can be offered by network service provider in terms of Service Level Agreement (SLAs) QoS can be offered by network service provider in terms of Service Level Agreement (SLAs) i) Network Availability ii) Guaranteed bit-rate iii) Payment model iii) Payment model iv) Other legal necessities iv) Other legal necessities

6 Why is QoS needed in UMTS? A main challenge for UMTS is to convey various types of traffics on the same medium while meeting their different QoS requirements, especially for real-time applications. UMTS Release 4 UMTS Release 5 Note: UMTS core networks evolution to all IP backbone.

7 The E2E UMTS QoS case we are investigating UEs UTRAN SGSNGGSN Internet Application Servers Two domain involved form end-2-End QoS point of view: UMTS domain QoS and IP domain QoS 2. Background

8 2.1 UMTS QoS Domain: End2End QoS Architecture 3GPP layered structure [1] 3GPP layered structure [1]

9 UMTS QoS - UMTS QoS classes Traffic classConversational class conversational RT Streaming class streaming RT Interactive class Interactive best effort Background Background best effort Fundamental characteristics -Preserve time relation (variation) between information entities of the stream Conversational pattern (stringent and low delay ) -Preserve time relation (variation) between information entities of the stream -Request response pattern -Preserve payload content -Destination is not expecting the data within a certain time -Preserve payload content Example of the application -voice-streaming video-Web browsing-background download of s

10 UMTS QoS provisioning Existing UMTS QoS mechanisms: Existing UMTS QoS mechanisms: - QoS profile - Traffic Flow Template (TFT) - PDP context What is missing in 3GPP standardization? What is missing in 3GPP standardization? - UTRAN part: QoS parameters mapping to Radio Resource Management strategies - UMTS core network part: IP layer transport mechanisms on the Gn and Gi interface

IP QoS DiffServ and InterServ comparison Integrated services Differentiated services State in routers (e.g., scheduling buffer management) Per-flow Per- Aggregate Traffic classification basis Several header fields The DS field (6 bits) of the IP header Admission control Required Required for absolute differentiation only Signaling protocol Required (RSVP) Not required for relative schemes; absolute schemes need semi-static reservations or broker agents Coordination for service differentiation End-to-end Local (per-hop) Scalability Limited by the number of flows Limited by the number of classes of service Network management Similar to circuit- switched networks Similar to existing IP networks

12 3. Problem Delimitation Network Architecture for QoS Conceptual Models

13 Problem Statement 1.External IP network: IETF standard QoS mechanism – DiffServ or InterServ 2.UMTS network domain: 1) QoS classes mapping between External IP QoS classes and UMTS QoS classes, and UMTS Bear Service (BS) attributes mapping to Core Network (CN) BS and Radio Access Bearer (RAB) and further to Radio BS and Iu BS. 2) Call Admission Control in every multiplexing point (GGSN, SGSN, etc) 3) GGSN policing: check downlink flow and filter it according to TFT 4) Scheduling and congestion mechanisms in CN transmission (I,e, WFQ, WRED, etc) 5) QoS differentiation implementation in RRM 3) Other open issues: Application level End2End QoS provisioning, i.e, SIP signalling

14 State of the Arts 1. Advanced Radio Resource Management for Wireless Services(ARROW) : This project aims at providing advanced Radio Resource Management (RRM) and Quality of Service (QoS) management solutions, for both UTRA-TDD and UTRA-FDD modes. It includes packet access, Asymmetrical traffic and high bit rate (2 Mbit/s) services for multimedia IP based applications. based applications. Although ARROWS concentrates on the QoS aspects of UTRAN, a global QoS framework is proposed, which is relevant with our work. 2. Advanced Services by Mastering UMTS (SAMU) : paris.com paris.comwww.samu.crm- paris.com The innovative work in QoS from SAMU includes UMTS/IP QoS mapping architecture and UMTS link layer optimization for TCP. The architecture includes both mapping between IP DiffServ and UMTS bearer and mapping from UMTS bearer to lower layer. from UMTS bearer to lower layer. We refer to the mapping between IP DiffServ and UMTS Bearer from this project.

15 3. Simulation of Enhanced UMTS Access and Core Networks (SEACORN) : Development, and implementation of resource management algorithms enabling QoS provisioning and differentiation while optimizing resource efficiency This project contribute a system level UMTS network simulator based on NS-2, named Enhanced UMTS Radio Access Network Extensions (EURANE), which named Enhanced UMTS Radio Access Network Extensions (EURANE), which We chose as the base of our simulator. Contributions and drawbacks of these related works: Contributions and drawbacks of these related works: a). Many E2E QoS frameworks were proposed but solid implementation and simulation output are still missing. b). QoS attributes mapping are designed but not implemented. c). These work more focused on the RRM implementation, no core network QoS mechanisms are considered. c). These work more focused on the RRM implementation, no core network QoS mechanisms are considered. d). None of the framework gives a clear picture about the impact of mixing real-time and non-realtime traffics on the QoS aspects.

16 Problem Delimitation Traffic: Mixed types of user data (real-time and non-real-time) flow from external application servers to UMTS User Equipments (UEs). And we only focus on downlink traffic flow. Traffic: Mixed types of user data (real-time and non-real-time) flow from external application servers to UMTS User Equipments (UEs). And we only focus on downlink traffic flow. For Internet/External network QoS -> IETF DiffServ approach was chosen. For Internet/External network QoS -> IETF DiffServ approach was chosen. Reason: more scalable and easy to manage when more than one network operator involved. Reason: more scalable and easy to manage when more than one network operator involved. In UMTS Core Network side: In UMTS Core Network side: 1) Mapping mechanism from DiffServ QoS classes to UMTS QoS classes in GGSN 2) Call Admission Control in GGSN considering required QoS profile and available equivalent bandwidth 2) Call Admission Control in GGSN considering required QoS profile and available equivalent bandwidth 3) Scheduling and queuing mechanisms to differentiate different UEs according to their UMTS service classes (Conversational, Streaming, Interactive, Background)

17 Simulation Tool – Network Simulator version 2 (NS-2) and its UMTS extension No PDP Context Functionality. No PDP Context Functionality. SGSN and GGSN are “Routers” from standard NS-2. SGSN and GGSN are “Routers” from standard NS-2. DiffServ functionalities are available DiffServ functionalities are available Some buffer management algorithms are available for congestion control, i.e. Random Early Discard (RED) Some buffer management algorithms are available for congestion control, i.e. Random Early Discard (RED)

18 4. Preliminary Simulation Simulation Scenarios: 1. Network Topology UE2 UE3 UE1 Node BSGSNRNCGGSN Appl. Server1 Appl. Server2 Appl. Server3 2Mb 10Mb 1Mb 10Mb

19 2. Traffic Model Constant Bit Rate (CBR) source for real-time applications Constant Bit Rate (CBR) source for real-time applications Exponential traffic source for non-realtime applications Exponential traffic source for non-realtime applications All traffic is working on UDP protocol All traffic is working on UDP protocol 3. Mobility Model none none 4. Propagation Model Ideal, Ideal, Standard NS-2 error model to be set in future 5. QoS mechanism Best Effort Best Effort

20 Simulation Result 1 User throughput when the total traffic load is lower then the bandwidth in Core network (SGSN-GGSN)

21 Simulation Result 2 User throughput when the total traffic load is higher then the bandwidth in Core network (SGSN-GGSN) Slightly overloadHeavily overload

22 Conclusion In case of Best Effort transmission, the real-time traffics will suffered from the mixing with non-realtime Traffics in case of network congestion.

23 5. Proposed End2End QoS algorithms CAC Mapping PDP Context generation through event based Database (At the time of event Generator and use it for CAC GGSNSGSN UE1 UE2 UE3 Edge Router Core Router DS 1

24 PDP Context generation through event based Event based PDP generation, Event based PDP generation, Acknowledgement based database for PDP Context Acknowledgement based database for PDP Context Event based Traffic generation, Event based Traffic generation, 1,2,3,4 is Available Bandwidth and 6 is an acknowledgement 1,2,3,4 is Available Bandwidth and 6 is an acknowledgement UE Node B Database: UE id,APN,BW Available, RNC SGSNGGSN Acknowledgement AS Total Duration : 60ms Duration : 50ms Duration : 55ms 2

25 Mapping UMTS QoS Attributes are Guaranteed Bit Rate and SDU size. UMTS QoS Attributes are Guaranteed Bit Rate and SDU size. IP QoS Attributes are burst size and arrival rate stored in traffic profile of the SLA. [2] IP QoS Attributes are burst size and arrival rate stored in traffic profile of the SLA. [2] Differentiated Services considered. Differentiated Services considered. IPv4 header field TOS is used for DSCP. IPv4 header field TOS is used for DSCP. Assured Forwarding is considered for the traffic class buffering. Assured Forwarding is considered for the traffic class buffering.

26 Mapping - continue Assumptions are IPv4, AF for PHB Assumptions are IPv4, AF for PHB Traffic Profile: Burst Size, Arrival Rtes Core Router: PHB Scheduling,Buffering DS1 GGSN Guaranteed Bit rate, SDU Size

27 Call Admission Control 1.Incoming Traffic class, 2.Check with the Database for the Resource reservation, 3.Set priority based on the Available BW and Traffic class, I.e Real-time: High priority, Non Real-time: Low Priority, 4.Scheduling, policy setting database GGSN ER SGSN External Net 3

28 Conclusion The most of technical paper or EU funded project proposed the the concept but none with the E2E aspect. The most of technical paper or EU funded project proposed the the concept but none with the E2E aspect. As the emphasis is on the Multimedia Services, Hence the mapping between the UMTS and the IP Network is the highest priority. As the emphasis is on the Multimedia Services, Hence the mapping between the UMTS and the IP Network is the highest priority. The proposed algorithm will offset the limitation of an available simulator with the implementation of Event based PDP Context and traffic generation. The proposed algorithm will offset the limitation of an available simulator with the implementation of Event based PDP Context and traffic generation. The purpose of the proposed topology is to design the algorithm which deals the End to End QoS aspect including mapping,Scheduling and resource reservation. The purpose of the proposed topology is to design the algorithm which deals the End to End QoS aspect including mapping,Scheduling and resource reservation. The proposed algorithm will reduce the end2end delay and packet loss probability The proposed algorithm will reduce the end2end delay and packet loss probability

29 Future Work Implementation of proposed topology and validation of proposed algorithm. Implementation of proposed topology and validation of proposed algorithm. To show that the mix of non real time application makes the real time application to suffer. To show that the mix of non real time application makes the real time application to suffer. To show the proposed queuing and scheduling technique will improve the real time application When it mix with non real time application. To show the proposed queuing and scheduling technique will improve the real time application When it mix with non real time application. To show the Guaranteed bit rate per user can be achieved even during the congestion. To show the Guaranteed bit rate per user can be achieved even during the congestion.

30 References [1] 3GPP TS [2] SAMU project, QOS Deliverable SP2-D1,

31 Backup Proposed Mapping in ASMU project [2]