Outline. Introduction End-to-end QoS in heterogeneous networks User-centric, cross-layered approach User-centric QoS in PLC Networks Conclusions

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1 Managing the User-Perceived QoS in Heterogeneous Networks Pedro M. Ruiz Project Manager Agora Systems S.A. Madrid 2003 Global Summit

2 Outline Introduction End-to-end QoS in heterogeneous networks User-centric, cross-layered approach User-centric QoS in PLC Networks Conclusions Pedro M. Ruiz Madrid 2003 Global Summit 2

3 Vision on Heterogeneous Convergent Networks Traditional IP-based networks SGSN PSTN Cable GGSN Core Network PLC SGSN DSL GSM/GPRS/ UMTS Mobility enabled Access Network Access Router Wireless Routers Mobile Routers Pedro M. Ruiz Madrid 2003 Global Summit 3

4 End-system QoS End-to-end QoS is more than network-layer QoS User-perceived QoS End-system QoS Session Link QoS Content presentation Session and Capabilities Negotiation Network-layer QoS Link QoS Link QoS Link QoS Session The chain is no stronger than its weakest link User-perceived-QoS = min(end-system QoS, Network-Layer QoS, min(link QoS)) Pedro M. Ruiz Madrid 2003 Global Summit 4

5 Problems affecting user-perceived QoS in heterogeneous networks At the link and physical layers... Not every technology is able offer strict QoS guarantees Some technologies are not QoS aware Link quality not always under control (e.g. PLC, WLAN,..) At the network layer... QoS mechanisms not unique among transport domains Difficult QoS orchestration among administrative domains Not real flow-awareness at the network layer ( may help!) At the upper layers... Terminal capabilities might be different (CPU, memory, battery, etc) Scarcity of local resources User requirements need to be mapped to network layer parameters There is a need for vertical cross-layered QoS mechanisms Pedro M. Ruiz Madrid 2003 Global Summit 5

6 Where to place these cross-layer QoS functions? UMTS Rel6 (IMS) WLAN Power Line Wired LAN Ad hoc W-CDMA b PLC-MAC Ethernet?? Media Gateways User-perceived QoS Mmedia fcns Profile & Policy Mgmt Signalling to L2 coupling Overall orchestration TCP UDP Serv.. provision Mmedia fcns Pedro M. Ruiz Madrid 2003 Global Summit 6 TCP UDP

7 Overall user-centric cross-layered QoS provision architecture Requirements PDP QoS broker Proxy User profiles b b Ethernet Ether POS POS POS POS Ether Ethernet b The QoS broker acts similar to a proxy-cscf in the IMS part of UMTS The QoS broker accepts only requests matching the user s profiles The QoS broker dictates general rules, which s map to specific parameters In varying network conditions, applications will adapt to provide a high user-perceived QoS Pedro M. Ruiz Madrid 2003 Global Summit 7

8 Application of the paradigm to provide QoS in PLC networks Pedro M. Ruiz Madrid 2003 Global Summit 8

9 How does a PLC access network look like? Ethernet CPE 220v lines Head End Core Network CPE Access Router CPE 220v lines Head End CPE CPEs & HEs may act both as bridges or routers RPTs could be placed between HE and CPEs Traditional equipments from HE to core network Pedro M. Ruiz Madrid 2003 Global Summit 9

10 Link-layer issues PLC link-layer capacity is highly variable 1 Mb 637 Kb 318 Kb Pedro M. Ruiz Madrid 2003 Global Summit 10

11 Link-layer solutions Implementation of different priority L2 queues (Control, CBR, VBR, UBR) Mapping from BW parameters to specific L2 PLC parameters (channel %, etc.) Mapping from session_ids to L2 label => L2 queues (IP, port) Flow label, etc. Variability left to upper layers COPS QoS Broker & Policy server Incoming SNMP Selector Labeler Classifier Scheduler Outgoing Pedro M. Ruiz Madrid 2003 Global Summit 11

12 Network layer QoS in PLC networks Network QoS based on QoS mechanisms messages will be used as implicit QoS signaling The in the access router will mark packets with DSCPs according to the QoS broker instructions (or even MPLS labels) The in intermediate routers will establish appropriate queuing disciplines The in the egress router will re-mark (if needed) according to SLAs with neighboring domains Ethernet CPE 220v lines QoS Broker & Policy server Core Network CPE Head End (bridge) marking Access Router Eggress Router Re-mark? COPS Pedro M. Ruiz Madrid 2003 Global Summit 12

13 Adaptive multimedia applications QoS violations may still occur due to the link variability Adaptive applications will adapt to the new network conditions in such resource scarcity periods Type % Lost Delay User Preferences Estimated BW App. Layer QoS signaling QoS signaling App. Layer Adaptation Logic Net. Layer Mon Net.Layer Mon Adaptation Logic Audio Video... Slides Audio Video... Slides TCP/UDP IP MAC PHY TCP/UDP IP MAC PHY Pedro M. Ruiz Madrid 2003 Global Summit 13

14 User-perceived QoS Traditional adaptive applications only adapt in terms of bandwidth and packet losses How does it affect the user s perception of QoS? Many application settings may reduce bandwidth consumption. Which one is the best? Is it possible to model the user-perceived QoS? The goal is to implement intelligent adaptation mechanisms, being able to offer efficient multimedia adaptation without compromising user-perceived QoS Pedro M. Ruiz Madrid 2003 Global Summit 14

15 Operation over an -enabled Power Line access network Control traffic pre-configured as highest priority Implicit QoS signaling using, QoS requirements inside SDP part QoS broker accepts/rejects according to profile, availability, etc. If accepts, reservation is established (COPS) both at L2 & L3 Else -CANCEL is sent back QoS violations are dealt with at app. layer Ethernet CPE QoS Broker & Policy server Core Network CPE 220v lines Head End (bridge) Access Router Eggress Router COPS Pedro M. Ruiz Madrid 2003 Global Summit 15

16 Conclusions QoS mechanisms and signaling will be key integration pieces in the next generation Internet Flexibility at the different layers will be the answer to many of the challenges in future heterogeneous networks Software defined radio Policy Based Network Management Flexible and active Networks Real-time adaptive multimedia services... Cross-layer tightly-coupled approaches offer excellent performance in unpredictably changing networks in which network-layer QoS alone is not enough Future QoS mechanisms should be user-centric, and their target should be the maximization of the overall user-perceived QoS. Pedro M. Ruiz Madrid 2003 Global Summit 16