1. Mobile Videophone Lauri Mäkinen April 26, 2007

2. Outline • Videophones in Fixed Networks • Mobile Videophone • Overview of Standards • Operator Business • User Perspective

3. Videophones in Fixed Networks (1) ”Just around the corner!” for 80 years

4. Videophones in Fixed Networks (2)- History • Video calling booths (1960s) • Booked in advance • $16 for a 3 minute call • Desktop videophones (1960s-1970s) • Picturephones I & II • $13.50 / minute (long distance, 10 times a regular voice call) • Videoconferencing (1970s-1980s) • Rentable rooms at $2340 per hour • Initial cost of $117 500 to own a room • Videophones for the masses (1980s-1990s) • Japanese enter the market • Regular phonelines • Employed video compression • Cost no more than regular voice call

5. Videophones in Fixed Networks (3)- Reasons for failure • Ahead of its time • Too expensive • Technology-centric (advanced features) • Early videophones required several regular phonelines • No consumer need • Although market research showed huge interest • Low quality • Standalone-technology • Network effect • Metcalfe’s law: value of a networked service is proportinal to (n2-n)/2 where n=number of users

6. Mobile Videophone • Technically very different than any other type of video service • Requires: • Very low latency • Synchronicity • To meet these requirements • Efficient but computationally light compression/decompression • Circuit switched data transfer

7. The standard - 3G-324M • Modified version of H.324 (the standard for modem based video telephony) • Added error resilience by enforcing some optional features of H.324 • Main parts: • H.223 – Multiplexing of different media types (voice, video, data) • Several levels, each adding error resilience • H.245 – Call control • Handles non telephone related call controls • Logic channel signalling, mode request, capability exchange • Video codecs • H.263 – Mandatory (considered legacy) • Doesn’t handle error prone bearer too well • MPEG-4 Visual codec (simple profile at level 0) – Recommended • Provides error resilience and cocealment

8. 3G-324M – Architecture Overview

9. Use Perspective • Purpose – sharing experiences and emotions • ”See-Me” • ”See-What-I-See” – thanks to mobility • Used with people close to you • Downsides • Less discrete than pure voice • Uncomfortable pose • Increased cognitive load • Sometimes people just don’t want show their faces

10. Operator Business • Helps to drive the adoption of 3G networks and services • Finnish operators offer video calls by default to all 3G customers • No opening fee • Charged by use • Example of deployment • Saunalahti – first in Finland (Janury 2005) • Price around 0.20€ / minute

11. Success Factors • Interoperability • The 3G-324M standard embraced by both 3GPP (UTMS) and 3GPP2 (CDMA2000) • Interoperable with VoIP by using gateways • Helps reduce network effect • Not a standalone product • Videotelephony is a part of the 3G offering • Synergy: 3G-324M used for mobile TV • Easy to use • Doesn’t require any setup • Reasonably priced • Quality of Service satisfactory (?)

12. Conclusions - SWOT