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Exploring a Framework for Developing the Future Internet: Lessons from the Y-Comm Architecture

Exploring a Framework for Developing the Future Internet: Lessons from the Y-Comm Architecture. Glenford Mapp Principal Lecturer, Middlesex University. Outline of the Talk. Motivation for the work Our approach Introduction to Y-Comm Peripheral Framework Areas of Work Conclusions.

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Exploring a Framework for Developing the Future Internet: Lessons from the Y-Comm Architecture

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  1. Exploring a Framework for Developing the Future Internet: Lessons from the Y-Comm Architecture Glenford Mapp Principal Lecturer, Middlesex University

  2. Outline of the Talk • Motivation for the work • Our approach • Introduction to Y-Comm • Peripheral Framework • Areas of Work • Conclusions

  3. Motivation (looking backward) • Originally we started with ubiquitous handover. • Fore-runner was work on the Cambridge Wireless network which looked how you do handover between different wireless systems • James Scott, Leo Patanapongpibul, Pablo Vidales • YComm ended up looking at ubiquitous handover, Quality-of-Service, Security and Application environments/Service Platforms

  4. Lesson -1.0 • Each of these are big areas in themselves • Can study each area on its own and that is what a lot of people are doing. • End up with good papers but not something that you could take and build a real system • We took the opposite viewpoint. • Try to describe the big picture first • Develop the mechanisms but keep always keep the big picture in view

  5. Lesson -0.5 • Don’t be foolish • Invent things only when you need to • Y-Comm is not trying to invent new technologies for the sake of it • Use standards or new technologies • Be futuristic • Take a guess but realize you could be wrong • Allow evolution • Be conservative

  6. Futuristic Assumption 1: Network Evolution • The Internet will evolve in a physical sense • Core of the network • Super-fast backbone (optical switching, etc) • Fast access networks (MPLS, ATM) • Peripheral Wireless Networks • Errors due to fading, etc; not just congestion • Handover • Consequences • Degradation of end-to-end arguments

  7. Internet Evolution BACKBONE ACCESS NETWORKS WIRELESS NETWORKS

  8. Futuristic Assumption 2: Heterogeneous Devices • Devices will have more than one wireless interface. • Vertical handover – switching between different network interfaces to provide seamless connectivity • Vertical handover is good but it introduces a lot of QoS issues because the different wireless networks have different qualities of service

  9. Vertical Handover (Sideffects) • Affects your connections • Some protocols react badly with respect to handover. • Affects your applications • Need to think through how Quality-of-Service affects applications • Encapsulate these ideas in a Framework

  10. Layer 5: Slow Adaptation of TCP After LAN->GPRS Handover

  11. Lesson 0.0 • New framework • We need to control network interfaces generically • Make mobility support explicit • Vertical handover can have tsunami effects • Merge network and transport services • Make QoS support explicit • Provide a way for applications to negotiate with the network

  12. The Complete Y-Comm Framework CORE NETWORK PERIPHERAL NETWORK APPLICATION ENVIRONMENTS SAS SERVICE PLATFORM QBS QOS LAYER NETWORK QOS LAYER CORE TRANSPORT END SYSTEM TRANSPORT NTS NAS NETWORK MANAGEMENT POLICY MANAGEMENT VERTICAL HANDOVER (RE)CONFIGURATION LAYER NETWORK ABSTRACTION (MOBILE NODE) NETWORK ABSTRACTION (BASE STATION) HARDWARE PLATFORM (MOBILE NODE) HARDWARE PLATFORM (BASE STATION)

  13. Y-Comm Group • Middlesex University • Mathematical modelling of vertical handover (TBVH) and the Stream Bundle Layer for Downward QoS (Fatema Shaikh) • Transport protocol and network architecture issues in Peripheral networks (Glenford Mapp) • Security (Mahdi Aiash) • Mobile Services (Fragkiskos Sardis) • University of Cambridge • Proactive knowledge- based policy mechanisms for handover (David Cottingham) • Networking issues (Jon Crowcroft)

  14. Y-Comm Group • University of Sao Paulo (ICMC San Carlos) • Ontological services for vertical handover • SoHand Middleware (Edson Moreira and Renata Vanni) • Core Network Management (Mario Augusto) • Federal University of San Carlos • Testbed based on IEEE 802.21 • Loughborough University • Security Framework in Y-Comm (Raphael Phan)

  15. This talk • Can’t explain everything about Y-Comm • It’s too big • Concentrate on the Peripheral Network • See Y-Comm Research Webpage: • http://www.mdx.ac.uk/research/areas/software/ycomm_research.aspx

  16. The Peripheral Framework APPLICATION ENVIRONMENTS LAYER QOS LAYER END TRANSPORT SYSTEM POLICY MANAGEMENT LAYER VERTICAL HANDOVER LAYER NETWORK ABSTRACTION LAYER HARDWARE PLATFORM LAYER

  17. Hardware Platform Layer Defines the physical requirements for a particular wired or wireless technology Expanded physical layer Includes electromagnetic spectrum Modulation and channel reservation algorithms Incompatibility issues Two technologies may be incompatible and cannot be used simultaneously Layer 1: Hardware Platform Layer

  18. Hardware Platform Layer Represented as Vertical Components 3G WLAN 802.11 WiMax 802.16 UltraWideBand

  19. But all this is about to change! • Need to make more efficient use of the electromagnetic spectrum • Cognitive Radio • A radio that is aware of and can sense its environment, learn from its environment, and adjust its operation according to some objective function

  20. Cognitive Radio (CR) • Technology • Software Defined Radio (SDR) • Wide spectrum receiver • Do the processing in real-time • Intelligent Signal Processing (ISP) • Allows it to detect interference and move to another part of the spectrum • Ideal cognitive Radio – Mitola Radio > 2030 • Mitola radio uses CR as the physical layer of a communications model • That’s why CR is part of Y-Comm

  21. Cognitive Radio SPECTRUM MANAGEMENT 3G WLAN WiMax UltrawideBand INTELLIGENT SIGNAL PROCESSING SOFTWARE DEFINED RADIO WIDE SPECTRUM REECIVER

  22. Layer 2: Network Abstraction layer • Network abstraction Layer • An abstraction that allows us to define, control and manage any wireless network on a mobile host • Key issues: data path functions; data formats (Link-layer), turning features on and off • Need to generate L2 triggers when a new network is detected or when an old network is no longer detectable • Build on 802.21

  23. Link Layer Triggers State Change Predictive Network Initiated Applications (VoIP/RTP) Connection Management Handover Policy Handover Management Network Information Available Networks Neighbor Maps Network Services Mobility Management Protocols IETF 802.21 MIH Function Handover Commands Client Initiated Network Initiated Vertical Handovers Smart Triggers Handover Messages Information Service IEEE 802.21 Handover Messages Information Service L2 Triggers and Events Protocol and Device Hardware WLAN Cellular WMAN 802.21 Overview 802.21: Key Services 802.21 uses multiple services to Optimize Vertical Handovers

  24. Layer 3: Vertical Handover Layer • Layers that define the mechanism for vertical handover. • Support for different types • Network-based • Client-based

  25. Client-Based Handover • More scalable for heterogeneous networks • Mobile node can monitor the status of all its network interfaces via the network abstraction layer • Can take into account other factors such as the state of TCP connections • Don’t want to do a handover during the start and termination of TCP connections

  26. Lesson 1.0 handover is complicated HANDOVER ALTERNATIVE IMPERATIVE SERVICES NETPREF CONTEXT REACTIVE USERPREF PROACTIVE UNANTICIPATED ANTICIPATED MODEL-BASED KNOWLEDGE-BASED

  27. Layer 4: Policy Management layer • Decides if, when and where vertical handover should occur. • Must be able to deal with all cases of handover • Reactive done • Proactive – most favourable but hard

  28. Reactive Policy: PROTON HIGHER LAYERS Interface Information L2 Triggers INPUT/OUTPUT LAYER POLICY LAYER (PONDER) HANDOVER EXECUTION LAYER LAN WLAN GPRS

  29. Layer 4: Proactive Policies • Proactive Policy Management • The mobile node can know or estimate the network state at a given point before it arrives at that point • Proactive Policies allow us to maximize the use of available channels provided you know the amount of time a channel will be available. • That time is known as: • Time before vertical handover (TBVH) • Can significantly reduce packet loss during all vertical handovers

  30. Layer 4: Proactive policies • Proactive policies can themselves be divided into 2 types • Proactive knowledge-based systems • Knowledge of which local wireless networks are operating at a given location and their strengths at that point • We also need a system to maintain the integrity, accessibility and security of that data

  31. Proactive Policies • Knowledge-based approach • Gather a database of the field strengths for each network around Cambridge • Need to maintain the database and also know how the results might be affected by seasonal effects

  32. Knowledge-Based Policy Management (Cambridge)

  33. Proactive Policies – Modelling Approach (Middlesex) • Using a simple mathematical model • Define a radius at which handover should occur • Find out how much time I have before I hit that circle, given my velocity and direction • Calculate TBVH • Used simulation (OPNET) • Can be used in the real world as well as in simulation

  34. The Model-Based Handover

  35. Predictive Mathematical Model for TBVH(Simple Case) Movement of MS under BBS coverage (upward vertical handoff) • Introduction of additional functionality to Base Station at network boundary (BBS). • Distance between MS and BBS derived from location co-ordinates or • Estimated TBVH

  36. Simulation and Results TBVH simulation in OPNET Modeler:

  37. Combining Transport and Communications to determine the optimum handover NET A A NET B S NET C B C T

  38. Analysis shows that it is possible to calculate these key points with some degree of accuracy C1 E1 Y2 Z1 A Y1 Y3 H1 C2 S B E2 C H3 E3 H2 T Z2 Z3

  39. This is getting interesting • Because we can not only work out TBVH • You can also calculate the amount of time a mobile node will be in a given network • Try to optimize handovers when networks overlap • Depends on the velocity (affects the exit radius) and adaptation time

  40. Vertical Handover GPS Location, Speed, direction Connections (QoS) TBVH New QoS New IP Polling CORE NETWORK Done NETWORK MANAGEMENT LAYER Send to Mobile TOPOLOGY, RESOURCES, QoS POLICY MANAGEMENT LAYER DECISION HANDOVER (BASE-STATION, 3G, QOS, TBVH) DO IT RECONFIGURABLE LAYER ACQUIRE CHANNEL (3G, BASE-STATION, QOS) VERTICAL HANDOVER LAYER ACQUIRE RESOURCES ( 3GCHAN, BASE-STATION, QOS) DO IT NETWORK ABSTRACTION LAYER BASE-STATION NETWORK ABSTRACTION LAYER DATA CHANNNEL = 3G 3G=ACTIVE WLAN=PASSIVE WiMAX= PASSIVE CHANNEL ACQUIRED L2 events Media Info 3G WLAN WiMax 3G WLAN WiMax

  41. Lessons 2.0: We need to move to Location-based Information infrastructure • Leads to better handover • Leads to a much better use of network infrastructure • It needs to tell the mobile node about individual networks • Power of the transmitter, where the access points are located. • It also needs to know about the relationships between the individual networks.

  42. Layer 5: End User Transport System • Specifies how data is routed to individual hosts and transport protocols for error correction, reliability and Quality-of-Service requirements • Encompasses Layer 3 and Layer 4 in the OSI model • Different approaches • Keep the same protocols as in the core network • Keep TCP/IP, but modify TCP • Don’t modify TCP but try to get it to respond more quickly to network outages • Try a completely new protocol suite

  43. Layer 5: The case for a new transport Infrastructure • A new transport system could be more suited for wireless networking • Do all machines have to have an IP address to use the Internet? • No.. Look at Network Address Translation (NAT) • Translation is done between a private address and port to a global address and port at the NAT server

  44. Layer 5: Continued • A global IP address in the case of NAT is really being used as an endpoint in the core network • So we can use another network scheme in the peripheral network once we can specify how we map it to TCP/IP or UDP/IP in the core network

  45. Y-Comm’s view of the Future PERIPHERAL WIRELESS NETWORK CORE NETWORK QoS, Secure Connection PERIPHERAL WIRELESS NETWORK Core Endpoints In Access Network

  46. View corresponds with other ideas • Faster LAN systems • Optimize DNS, streaming video from local caches • Integrate protocol with applications • Tuneable transport • Remove the user/kernel limitations • Use as a local signalling protocol • Encapsulates TCP packets

  47. Simple Protocol DEST_ID SRC_ID CHKSUM PK_TYPE PRI CB Flags TOTAL_LEN PBLOCK TBLOCK MESS_ACK_NO MESS_SEQ_NO SYNC_NO WINDOW_SIZE

  48. The Simple Protocol • DEST_ID (16) – identifying remote end • SRC_ID (16) – from source end • PK_TYPE (4) - packet type • PRI (2) - supports 4 priority levels • CB (2) – supports ECN • CHKSUM (16) – sixteen bit checksum • TOTAL_LEN (16) – total packet length • PBLOCK (8) – the present block • TBLOCK (8) – the total number of blocks • MESS_SEQ_NO (16) – last message sent • MESS_ACK_NO (16) – last message received • SYNC_NO (8) – the last ACK received • WINDOW_SIZE (24) – the window size

  49. Lesson 3.0: Local support is now essential to the Future Internet • Presence of heterogeneous networks • Support for mobility • Need for local signalling • Need for local transports • Don’t need to change TCP • Need for local knowledge • Can’t ignore that any more

  50. Heterogeneous Networking and Multi-homing • Because devices will have several interfaces, there will be multi-homing issues • Solutions such as Mobile IP which depend on Home and Care-of-Addresses are not scalable • SCTP helps but works on the transport level only • Need to look at the network addressing scheme

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