1 Ubiquitous Computing in Home Networks Henning Schulzrinne, Columbia University Stefan Berger, IBM Research IEEE Communication Magazine 2003

2 Everyone can communicate to Everything Everywhere E-E-EE-E-E

3 Ubiquitous Computing Multimedia Device integration Event-based Location-aware Privacy-conscious Invisible to user

4 System Architecture The context around the user Location information Multimedia resource The intelligent end system the user hold Retrieves the location and resource information Transfers the information to SIP server Control the resources

5 Ubiquitous Computing System Architecture

6 System Architecture The core of the intelligent end system Location sensing Resource discovery and management Call control

7 Location Sensing Self determines GPS Useless indoor The field strength of wireless access point Need two APs Location beacon Bluetooth IR/RF DHCP Server

8 Location-Based Service Triggers automated behavior Selects watchers Governs communication behavior

9 Location-Based Service Two control mode User centric Selects the types of devices for witch the user has defined preference Device centric Device subscribe to user presence and store preference

10 Resource Discovery and Control Back-to-back user agent A logical entity that receives a request and processes as a user agent server(UAS) And acts a user agent server(UAC) to determine how to answer the request and generates requests

11 Call Control Event-triggered actions Received from the location sensing Service discovery Inbound or outbound call

12 Control Messaging Using SIP Text-based message XML HTTP Encode as URI parameter SOAP(Simple Object Access Protocol) More powerful More complex

13 Access Control Explicitly registered to local server RADIUS or DIAMETER (AAA) Location information

14 Prototype Implementation The CINEMA system Columbia InterNet Extensible Multimedia Architecture SIP proxy, redirect, registration server(SIPD) SIP voice mail SIP conference service Service logic execution environment(SLEE)

15 SIP-based ubiquitous computing in a hotel Visited domain

16 Conclusion Presented a global-scale ubiquitous computing architecture Based on standard SIP and SLP Implementation CINEMA system