Network-Centric Architecture for Context- Aware Information Delivery Services in 3G Mobile Networks Eiji Kamioka 1, Shigeki Yamada 1 and Takako Sanda 2 1 National Institute of Informatics 2 The Graduate University for Advanced Studies 1 {kamioka, 2

Introduction Ubiquitous Computing Ubiquity Invisibility --- Context Awareness Context-Aware Computing Context-aware information delivery services At Any time and anywhere From LAN to WAN From indoor to outdoor From stationary to mobile environments CAIDS: Context-Aware Information Delivery System

Context-Aware Service Scenarios Tour guide in Paris I want to visit the Eiffel Tower! How can I get there? Personal communication service Context Location: on an airplane Activity status: sleeping Available device: headset

Functional Requirements of Context-Aware Services Context-Awareness Captures and updates users context The captured context is stored in a context database Deals with frequent changes and reuse of the context. Information Binding Analyzes and interprets the context Binds the context to the content Information Provision Converts the media content into one adapted to the receivers communication environment, if necessary. Delivers the (converted) content to the receiver at the right time in the right way Context Content binding

System Architecture Function Modules UIN (Universal Information delivery Navigator) DA (Directory Agent) UMD (User Management Database) MPS (Media Processing Server) UIN UMD DA MPS MT Content Server context authentication Query of content discovery Location of content server content Query of download Conversion if necessary MT: Mobile Terminal

WLAN MTR ISP network AP PS-CN RNCBSMT IMS I-CSCF SGSN UTRAN P-CSCF HSS GGSN T-SGW S-CSCF MGCF MGW R InternetPSTN/ISDN UMTS Release 5 WLAN UMTS Release 5 Architecture Integrated with WLAN Access Network for CAIDS

Communication Receiver Communication Sender CAIDS User Content Server EAPEC CAIDS Network Communication Context User Context Media Contents Analysis Adaptation Conversion Analysis Adaptation Conversion Comparison between CAIDS and EAPEC

PS-CN RNCBSMT IMS SGSN UTRAN WLAN MT R ISP network AP Content Server Internet LAN P-CSCF R I-CSCF S-CSCF UMD MPS DA CAIDS (1) (2) (3) (7) [5,10] (4,9) [6] (8) (11) [12] [13] [14] [15] [16] UIN CAIDS Architecture with Access Network GGSN R HSS User information is managed by the UMD through GGSN

I-CSCFS-CSCFMTUMDUIN DA P-CSCF REGISTER OK Content Server HTTP GET HTTP OK (download) (1)(2) (3) (4) [5] [6] (7) (8) (9) [10] (11) [12] [13] [14][15][16] Authentication + Get S-CSCF Refer to UMD + Get location of content server Response time Information Flow in CAIDS SIP SLP Based on the 3GPP specification

ParametersTraffic Distribution Values for Calculation and Simulation Wireless-Released Delay either in MT, UTRAN and PS-CN or in MT, WLAN and ISP network Normal Distribution 10 ms, as an average 3 ms, as an standard deviation IP Network Delay in the IMSNormal Distribution 10 and 20 ms, as averages 3 and 4 ms, as standard deviations Processing Time in Application Servers Exponential Distribution 10 and 50 ms per IP packet Utilization of Application ServerConstantFrom 0.1 to 0.9 with the interval of 0.1 IP Packet Arrival RatePoisson Distribution Arrival rates are determined so as to satisfy the specific utilizations of application servers Processing Time in MTConstant10 ms Performance Model Parameters Values for Calculating and Simulating the Response Times

Response time under server processing time of 10ms and network delays of 10ms and 20ms [ND]: Network Delay (ms) [PT]: processing time (ms) Response time under server processing time of 50ms and network delays of 10ms and 20ms Performance Results and Analysis

Conclusion CAIDS: Context-Aware Information Delivery System Concept System architecture Disposition of function modules Including personal communication services Preliminary performance evaluation Future work Implementation of CAIDS prototype into test bed network