Fundamentals Dr. Kun Yang University of Essex, Colchester

Lecture #1

Network & Service Convergence -- Fundamentals

Dr. Kun Yang University of Essex, Colchester, UK

Thursday 14th October 2010 @ NII, Tokyo

Agenda

Network Convergence Wireless + wireless Wired + wireless (fixed + mobile) Service Convergence Converged Services for Mobile Devices Converged Services for core networks Q&A

1 Driving Forces

There are many different types of wireless access networks. There will be no perfect wireless system in terms various factors such as mobility, capacity, coverage, and cost. Instead, these networks, each with its unique features, will co- exist. IEEE802.11a/b/g/n IEEE802.15.1 IEEE802.15.3a (Wireless LAN) (Bluetooth) (UWB) IEEE802.15.4 RF-tag (ZigBee) DVB-H IEEE802.15.4a (low-rate UWB) DVB-T Wireless Access Networks IEEE802.16-2004 Satellite (Fixed Wireless MAN) 3G Cellular (UMTS, CDMA2000, IEEE802.16e TD-SCDMA) (Mobile Wireless MAN) 2.5G (GPRS) 2G Cellular IEEE802.21 IEEE802.20 2.75G (EDGE) (GSM, etc) (MIH) (Mobile BWA) There is a historic shift from PC’s to mobile devices for Internet access. Technologies that enable users to seamlessly and easily use these networks are needed. 3

A Heterogeneous Wireless Network: UMTS+WiFi

Current cellular systems are As a result, some cells limited in flexibilities in that could be congested cellular architectures are fixed because of temporary and bandwidth allocation events, such as traffic cannot dynamically adapt to accidents and sports instant network change. events.

Proposal: introduce MANET over cellular networks to divert traffic.

Existing work: iCAR: diversion station has only cellular interface UCAN: high-date rate, within a cell 4

2 Physical Characteristics of the HWN system

MH2

Traffic Diversion Station #1

Mobile Host #1 TDS3 TDS2 Base Station #1 BS2 MH4 MH3 MH5

Cellular Interface Ad Hoc Interface BS: no change from the current UMTS BS TDS: with both cellular and ad hoc interfaces, deployed close to the borders of a cell MH: with only A-interface, C-interface, or both interfaces. 5

Adaptive Routing

Start End

Not needed in normal routing MHs initiates a request Transmit data from MHs but blocked using route r

YES MH j releases channel; Is there a TDS next MH ’ uses the channel; Source Selection to MHs? NO NO Destination Selection YES Is MH ’ empty? Source Selection Procedure : Route discovery & find a MH j in the same cell as MHs selection Route Selection YES Procedure: r=r Is MH j empty? failure k

NO NO

MH ’=MHs; YES MHs=MH j; Is R empty?

Route Discovery Destination Selection Procedure: Procedure discover route 6

R={ rk|k=1,..,| R|}

3 QoS: QoS Mapping Heterogeneous Wireless Network Home WLAN BS TDS IP Internet aDSL (RSVP/DiffServ/ Router AP Egress MPLS) Router

Home Server (video) C-interface C-to-A A-to-C A-interface mapping mapping Wired HWN QoS Routing Internet QoS Routing interface

End-to-end QoS K. Yang, et. al. “ QoS-Aware Routing in Emerging Heterogeneous Wireless Networks ”, IEEE Communications Magazine , Feb. 2007. Page(s): 74-80.

Further Integration with DVB

Focus is on the DVB-H: Digital Video Broadcast-Handheld DVB Base Station network architecture and its service-driven • Three types of nets • Unicast+broadcast adaptation and mngt. • Uplink for DVB via cellular net. MH9 MH2 Cellular MH5 Cell

DVB MH1 Cell MH4 Base Station #1 BS2 MH8 MH6 MH3 MH7

Cellular Interface DVB-H Downlik Ad Hoc Interface It utilizes a policy-based mngt (PBM) approach in combination with fuzzy control theory, aiming to maximize the 8 overall effectiveness, flexibility, and robustness of the network.

4 Overall architecture UWD ServiceUWD Gateway

WLAN overlays UMTS. UMTS and DVB-H networks operate separately but connected via a pair of signalling gateways. UWD Service Gateway monitors the UWD network status and conducts network selection and configuration to satisfy user-perceived services. K. Yang, et al. “ A Flexible QoS-aware Service Gateway for Heterogeneous Wireless Networks ”, IEEE Networks , March 2007. Page(s): 6-12. 9

Operations

How the three types of networks collaborate to fulfill a service as coordinated by the USG.

5 Agenda

Network Convergence Wireless + wireless Wired + wireless (fixed + mobile) Service Convergence UEssex Research Test-bed Q&A

K. Yang, et al. “The Convergence of Ethernet PON and IEEE 802.16 Broadband Access Networks and its QoS-aware Dynamic Bandwidth Allocation Scheme”, IEEE JSAC, Volume 27, Number 2, February 2009: 101-116. 11

Background

IEEE 802.16 provides wireless broadband access with high bandwidth capacity, large network coverage, strong QoS support. But how to backhaul its traffic? -> EPON (Ethernet Passive Optical Network), a point-to-multipoint optical access network technology. The most popular EPON topology is tree-based architecture where transmission occurs between an optical line terminal ( OLT ) and multiple optical network units ( ONUs ). The OLT is usually connected to the core networks whereas each ONU locates at either curb (thus the so called fiber-to-the curb or FTTC), within a residential building (i.e., fiber-to-the-building or FTTB), or even to the home (i.e., fiber-to-the- home or FTTH). Of course, an ONU can be connected to an IEEE 802.16 base station (BS).

6 Illustration of an EPON Network Backhauling IEEE 802.16 Access Networks

OLT ONU BS SS

ONU 802.16 BS ... VOD Client SS C ore 1: n O NU 802.16 BS OLT splitter ... SS

SS VOD Server ONU Residential Building

We assume that an EPON ONU is integrated with an 802.16 BS into a converged box called Virtual ONU-BS (VOB) .

Partially funded by TSB/EPSRC Project: HIPnet 13

Why this Convergence?

Firstly, most 802.16 BSs are equipped with Ethernet interface as such can be easily connected to EPON. Secondly, both technologies share many similarities in terms of bandwidth request/allocation and QoS supporting mechanisms. Thirdly, EPON and 802.16 also complement each other in that the convergence of two has the potential to combine the bandwidth advantage of optical networks with the mobility feature of wireless communications. Furthermore, this integration enables the design of joint bandwidth allocation/reservation, connection admission control and transmission scheduling schemes. These collaborative schemes are more likely to provide a close-to-optimal solution to system’s overall resource management, including both wired optical resources and wireless radio resources. In return, a better support of end-to-end QoS guarantee and improvement of overall system performances such as throughput and delay can be expected. But how to design such schemes is still an open and challenging issue! We endeavor to make a first-step attempt towards this challenge by focusing on 14 bandwidth allocation.

7 A bit of state-of-the-art on FMC

Application Layer: IMS (IP Multimedia Sub-system)/SIP (Session Initiation Protocol) -> loads of work Physical Layer: Radio over Fibre (RoF) -> tons of work MAC Layer C. Qiao. et al. appears to consider FMC in a layer other than physical layer or application layer. However, this seminal work does not reflect too much the flavor of 802.16 networks. IEEE OFC March 2006 – seminal work Shen et al. recently summarize the architecture issues arising in the integration of EPON and 802.16. but not concrete algorithm details presented. Ref. IEEE ComMag, Aug. 2007 – work at roughly the same timeline as ours. Our work endeavors to design a QoS-aware dynamic bandwidth allocation (DBA) scheme at the MAC layer for a converged network of EPON and 802.16.

Technical Focus

Firstly, to propose converged network architecture of EPON and 802.16 (especially the concept of VOB) and identify the unique research issues as a result of this convergence. Secondly, to investigate a DBA scheme that is specifically designed for the WEN networks. This DBA scheme takes into consideration the specific features of the converged network to enable: (1) a smooth data transmission across optical and wireless networks, (2) an end-to-end differentiated service to user traffics of diverse CoS (Class of Service) requirements. Here the end-to-end means from a connection originated from an 802.16 SS to the OLT. • This QoS-aware DBA scheme shall ensure certain fairness under network traffic saturation condition along both station dimension and CoS dimension. • CoS fairness specifically means that the low-priority traffic (such as best effort traffic) shall not be significantly disadvantaged under network saturation condition. The proposed DBA scheme, called WE-DBA for WiMAX-EPON DBA 16

8 Virtual ONU-BS (VOB) Box

logical architecture

hardware layout

Bandwidth Request & Grant

• The VOB queues are presented as virtual queues by dashed lines because these queues represent the bandwidth requested instead of the real data. • EPON: Multi-Point Control Protocol (MPCP); IEEE 802.16 has similar mechanism and procedure. • These standardised mechanisms have defined the precise format for bandwidth request and grant messages as well as their processing. However, no DBA algorithm is specified. • Note that VOBs employ MPCP for bandwidth request and the 802.16 mechanism for bandwidth grant. 18

9 Illustration of Bandwidth Request and Allocation

Grant per CoS

Refer to the IEEE JSAC paper for technical details and discussion. 19

DBA at OLT

(T EPON − n ×T ) × R n: # of VOBs; Tg : guard time Bavg = cycle g VOB 8 × n R Mbps: EPON trans. rate

3 req = req i: VOB; j: CoS Bi ∑Bi, j j =1

n excess = avg − req avg > req B ∑(BVOB Bi (|) BVOB Bi ) i=1

g = avg + excess req Bi min( BVOB Bi , Bi )

len = g × Written in the MPCP GRANT message ti (Bi /)8 R 20

10 DBA at VOB

min = α × avg BBE BBE avg = BBE ,r+1 Traffic BE ,r avg = avg + BBE ,r +1 (BBE ,r −1 Traffic BE ,r 2/)

Evaluation Design

Benchmarks: DBA1: both the OLT and VOBs statically allocate bandwidth (equal share) to its client stations. DBA2: EPON static whereas 802.16 dynamic (the other way round is less common) Test design: To evaluate against benchmark to show the benefit of dynamic • in terms of throughput and delay To evaluate itself under different conditions. • In terms of throughput and delay under different serving cycles, types of services, channel utilization, and BE windows

11 Overall Throughput of WEN under different DBA schemes

Average Delayof WEN under different DBA schemes

12 Thoughput under different Serving Cycles

Delay under different Serving Cycles

13 Average Delay for Types of Services

Channel Utilization

14 Effect of minimum bw allocated to BE

Conclusions

PON+802.16 at MAC appears to be beneficial though just some very limited preliminary work being carried out. However, this is a massive research topic and much more effort is needed. Other topics such as scheduling and admission control, a comparative study on the performance differences between a centralized control mechanism (carried out by the OLT) and a cascading decision making strategy. Investigation into the effect of mobility on network performance. Long-term work includes research into a fully unified hardware VOB.

15 Agenda

Network Convergence Wireless + wireless Wired + wireless (fixed + mobile) Service Convergence Converged Services for Mobile Devices Converged Services for core networks Research Test-bed Summary, Q&A

Pervasive Service Engineering

Service Creation generates EPSRC Project: PANDA Policies Pervasive Service Module BT Project: MOSE Registers context Pervasive Service Information Model A range of research issues Static Service Creation concerning the whole lifecycle of Dynamic Service events PS Ad hoc Service Execution/Adaptation Context Monitoring pervasive service engineering: Module Adaptation Discovery Module Module Service Description, Service Java Virtual Machine Creation, Service Deployment, Network APIs Service Discovery, Service

Active Passive Composition, Service Sensor IP IP 3G/4G Network Sink Router Router handset Adaptation. Fixed IP WiFi mobile Node Node Basic methodology: - saturated to every stage of the PSE lifecycle Policy-based : more flexibility, and matching with the network management method Model-driven (OMG MDA-Model-driven Architecture): platform-, language- and middleware-neutral features, and open source from Eclips. Context-awareness 32

16 A GUI for Pervasive Service Creation

2 1

PS Execution Environment

Android Version

PC/PDA Version

17 Demo (source code free downloading)

Service Convergence at Core Networks

EU FP7 ICT Project – GEYSER (Generalised Architecture for Dynamic Infrastructure Services), 4th call, starting on 1 st Jan. 2010. to support 'Optical Network + Any-IT' resource provisioning; green issues

36 With Prof. Dimitra Simeonidou ([email protected])

18 Contact ，Q&A

Dr Kun Yang, Reader School of Computer Science & Elec. Eng. (CSEE), University of Essex, Wivenhoe Park, Colchester, CO4 3SQ, UK Email: [email protected] http://privatewww.essex.ac.uk/~kunyang/