Context-Aware Resource Management for Mobile Servers C. Ververidis, E.C. Efstathiou, S. Soursos and G.C. Polyzos Mobile Multimedia Laboratory Department of Computer Science Athens University of Economics and Business Athens, Greece

HP-OVUA Workshop, Geneva, July 6-9, Outline Technology Trends Location-Based Services The Service Provision Environment Network Architecture Implementation Mechanisms

HP-OVUA Workshop, Geneva, July 6-9, Technology Trends Computing and Telecommunication technologies convergence –From the WWW to the Mobile Web –Need for anytime anywhere access to information Abundant access bandwidth, storage, and processing power at the edges of the network –Emergence of low-cost wireless access technologies, e.g. IEEE Bluetooth –Emergence of Peer-to-Peer (P2P) service models Next-generation terminals –Small devices with server-like features and capabilities

HP-OVUA Workshop, Geneva, July 6-9, Location-Based Services (LBS) Mobile Web and LBS are evolving together The Case for LBS –Innovative, useful services attract new customers enhance customer loyalty to the provider –Revenue increase due to traffic generated by the use of such services Traditional business models for LBS vary depending on the number of participants in the LBS value chain LEVEL OF LBS REVENUE SHARING Mobile operator provides connectivity, positioning and content Mobile operator provides connectivity. Positioning and content are provided by external providers MinMax

HP-OVUA Workshop, Geneva, July 6-9, New LBS Model Mobile Operator provides –Connectivity –Positioning Technologies –Service Advertisement & Discovery Infrastructure Mobile Subscribers provide –Content, possibly sensitive to time and space changes Operators network externalities depend heavily on customers content

HP-OVUA Workshop, Geneva, July 6-9, Service Provision Environment Wireless Access Provider (WLAN or UMTS) –Access Point (AP) or Base Station (BS) covering an area of interest Some Mobile Subscribers can act as servers and offer content –Mobile devices with attached digital cameras Content sensitive to place and time –e.g. photo-series or low length/quality videos that provide information on the traffic conditions in the coverage area Content available only in the specific coverage area –No value outside due to space and time sensitivity and the high costs of transferring it

HP-OVUA Workshop, Geneva, July 6-9, Assumptions Network operator has the infrastructure for Service Advertisement and Discovery –Centralized or de-centralized Network operator possesses a positioning technology –From COO and OTDOA-IDL to GPS –We use a simple approach based on SINR values measured from the AP

HP-OVUA Workshop, Geneva, July 6-9, Example: Traffic Conditions Each mobile server –with the appropriate equipment (e.g. photo camera) –can offer (to other mobile subscribers) traffic condition information (including photos or short videos) The service is only available within the APs coverage area

HP-OVUA Workshop, Geneva, July 6-9, Environment Set-up Single AP Coverage area spreads along a main traffic road Subscribers are informed about the traffic condition of the specific road Extension: Multiple APs Covering and providing traffic information for many roads

HP-OVUA Workshop, Geneva, July 6-9, Architectures Goals Give the mobile server the appropriate uplink bandwidth to serve the requests Provide the mobile subscribers/clients the appropriate transfer rate according to their relative position to the mobile server Keep the content inside the coverage area by favoring content exchanges between mobile servers

HP-OVUA Workshop, Geneva, July 6-9, Architecture Differentiate uplink rates for each server-client pair and according to their relative position UMTS: –At the Radio Resource Management (RRM) located at the Radio Network Controller (RNC) IEEE WLANs: –Software upgrades at the Access Point to support advanced queuing disciplines (other than FIFO) Mobile Server Mobile Client Inner Circle Middle Circle Outer Circle Inner Circle10kbps 20kbps Middle Circle10kbps20kbps50kbps Outer Circle20kbps 50kbps

HP-OVUA Workshop, Geneva, July 6-9, Implementation Need for a QoS context-aware scheme Two approaches: –LBS-DF Based on IETF Differentiated Services –LBS-IS Based on IETF Integrated Services Different implementation for each technology –UMTS vs. IEEE WLAN

HP-OVUA Workshop, Geneva, July 6-9, LBS-DF Approach We define 3 QoS classes (from 1 to 3) –Class 3 is the class with the higher priority –Different transmission rates for each class 3 flow-serving queues at AP with different serving rates Extra packets are dropped or treated as in Assured Service class AP changes the QoS class according to the power readings and transparently to the mobile user Mobile Server Mobile Client Inner CircleMiddle CircleOuter Circle Inner CircleQoS Class 1 QoS Class 2 Middle CircleQoS Class 1QoS Class 2QoS Class 3 Outer CircleQoS Class 2 QoS Class 3

HP-OVUA Workshop, Geneva, July 6-9, LBS-IS Approach Several queues at AP, each serving a flow for a mobile server – client session A Scheduler module keeps an NxM array –N: number of mobile servers –M: number of mobile subscribers CAC in order not to exceed total available bandwidth –~5 Mbps for WLANs and 2 Mbps for UMTS Goal: –Maximize the number of completed file transfers Mobile Clients Mobile Servers ABCD AX10kbps50kbps20kbps C10kbps30kbpsX50kbps D100kbps20kbps40kbpsX

HP-OVUA Workshop, Geneva, July 6-9, UMTS Issues Throughput that a mobile server has on the uplink is based on the chip rate received from the BS Differentiating the chip rate differentiating the transmission rate Proposed QoS classes are different from the UMTS QoS classes –UMTS QoS classes: generic QoS, same for all traffic in our service environment –Proposed QoS classes: lower-level QoS

HP-OVUA Workshop, Geneva, July 6-9, IEEE WLAN Issues Upcoming e standard: –A new MAC layer algorithm (Hybrid Coordination Function – HFC) –WLAN AP acts as a point coordinator and polls mobile stations for data, similar to the UMTS mechanism –Use of CF-Poll messages in HFC: Expected start time of transmission Maximum duration of transmission

HP-OVUA Workshop, Geneva, July 6-9, Summary New mobile technologies and LBS are forming a new business model for service provision Mobile Servers offering content sensitive to place and time changes Network architecture with the AP configuring mobile servers uplink bandwidth –DiffServ vs. IntServ approach –UMTS vs. IEEE WLANs

Thank you! C. Ververidis, E.C. Efstathiou, S. Soursos and G.C. Polyzos Mobile Multimedia Laboratory Department of Computer Science Athens University of Economics and Business Athens, Greece