APPLICATION PROGRAMMING: MOBILE COMPUTING [ INEA00112W ] Marek Piasecki PhD Mobile Multimedia Services (W14/2013)

Transcription

1 APPLICATION PROGRAMMING: MOBILE COMPUTING [ INEA00112W ] Marek Piasecki PhD Mobile Multimedia Services (W14/2013)

2 3G Enables New Services The bandwidth and location information available to 3G devices gives rise to applications not previously available to mobile phone users: Mobile TV a provider redirects a TV channel directly to the subscriber's phone. Video on demand a provider sends a movie to the subscriber. Video conferencing subscribers can see and talk to each other. Tele-medicine a medical provider monitors or provides advice to the potentially isolated subscriber. Location-based services: provider sends localized weather or traffic conditions to the phone, phone allows to find nearby businesses or friends.

3 What do the Mobile Users Want? Information? Entertainment? Communication? Games? Education? Shopping?...?

4 Research Results Proposed services: Live events enables following live events when the participants are not able to watch the event at home/pub, e.g soccer fun at a bus stop. News and weather provides a very recent news and/or weather update Disaster management e.g. temperature map of an urban area and the traffic diversion map Mobile TV and radio PVR (Personal Video Recorder) allows for recording of favourite programmes on the handset, would record similar shows based on previous choices Dating users would receive profiles of other potentially compatible users. The service might also include video clips of people introducing themselves. Language courses supplement to regular language courses that would help participants maintain and improve their language skills. Provide extra practice in the language of study.

5 The Multimedia Babel Tower

6 Mobile Multimedia Computing Requirements Example Video for wireless multimedia: Quarter size video 10 fps, encoded at kbps, requires transmission capacity of 2-50 voice conversations Full size video,at 30 fps, requires 32 GSM channels

7 Different Service Paradigms (1) Conventional Broadcasting Unidirectional Point to multipoint Real-time or not Low delay but not critical High quality Generic content Centralized content production model Several channels and networks Interactive Broadcasting Bidirectional but asymmetric Point to multipoint and pointto point Real-time or not Critical reaction delay High quality Generic content Centralized content production model Several channels and networks Storage Local, no transmission High storage capacity Very high quality Low delay Generic content Centralized content production model Mainly optical storage

8 Different Service Paradigms (2) Personal Communications Bidirectional and symmetric Point to point Real-time Critical delay Low or medium quality Specific content Several channels and networks Games Storage (or bidirectional) Point to point (or multipoint) Real-time Critical delay High quality/realism Synthetic and natural content mix Centralized content production model Mainly optical storage Monocasting Sharing Bidirectional but asymmetric Downloading and streaming Point to point Real-time (down) and no realtime (up) Critical delay Large range of qualities Distributed content production model (prosuming) Sharing approach Social networking Several channels and networks

9 Victorious i-mode Service (Japan, Year 2000)

10 Do Communications Over The Mobile Network In the year 2010, 54 millions subscribers to FOMA, first 3G mobile service (launched in 2001)

11 DoCoMo - mode Architecture

12 Messaging Migration from SMS to Mobile Multimedia All messaging services including SMS, MMS & collected under one application Pictures and videos can be stored in one photo album MMS messaging can combine text, pictures, video and audio The address formats supported are global phone numbers and simple addresses

13 MMS (Multimedia Messaging Service) Allows for the exchange of messages containing multimedia elements to and from mobile phones, extends the core SMS(Short Message Service) capability (which only allowed exchange of text messages up to 160 characters), as a slide show, MMS can be composed of: text, pictures, audio, video, ringtones the most popular use is to send photographs from camera-equipped handsets, popular method of delivering news / entertainment / advertisement standard developed by the Open Mobile Alliance(OMA), in cooperation with 3GPP and WAP groups.

14 MMS Supported Formats Depends on device type minimum is to support US-ASCII, apart from that could be: Adaptive Multi-Rate (AMR) codec for natural audio, Motion Picture Experts Group (MPEG) video, Audio Layer-3 (MP3), Musical Instrument Digital Interface (MIDI) Joint Photographic Experts Group (JPEG) Graphics Interchange Format (GIF) Wireless bitmap (WBMP) Synchronized Multimedia Integration Language (SMIL) Wireless Markup Language (WML) Hypertext Markup Language (XHTML)

15 MMS Reference Architecture

16 MMS Delivery Process MMS messages are delivered in a different way than SMS: 1. Sending device encodes the multimedia content similarly to sending a MIME (MIME content formats are defined in the MMS Message Encapsulation specification) 2. The message is then forwarded to the carrier's MMS store and forward server, known as the MMSC. 3. If the receiver is on another carrier, the relay forwards the message to the recipient's carrier using the Internet. 4. MMSC server determines if the receiver's handset is MMS capable (that is it supports the standards for receiving MMS). 5. If so, the content is extracted/converted (into a format suitable for the receiver) and sent to a temporary storage server with an HTTP front-end. 6. An SMS control message containing the URL of the content is then sent to the recipient's handset 7. Received control message, triggers the receiver's WAP browser to open and receive the content from the embedded URL.

17 Mobile TV (bringing video and audio content/services to mobile devices)

18 Mobile TV Technologies Two main approaches can be distinguished: unicast / streamed Mobile TV e.g. a UMTS or HSDPA connection could be used to stream a specific TV channel to an individual terminal ideal for on-demand personalised video services however, it is costly and not feasible for very large numbers of users broadcasted TV all viewers get access to the same channels unlimited numbers of users can access the service

19 Streamed Mobile TV Mobile TV via down-streaming of TV or media channels over mobile networks like UMTS, WiFi, WiMAX It is particularly suited for personalised services, like video on demand and pay-per-view services, interactive, mobile network-related services where audio-visual media are used (e.g. advertisements, location-/web- based services, virtual tourist guide). has videly been offered as commercial service by various service providers, such as Orange and Vodaphone Simultaneous transmission of TV content through live video streams could rapidly become problematic due to network congestions It will probably develop into a kind of niche market for personalised and on-demand video streaming

20 Broadcasted TV Main technologies considered for mobile broadcasting (terrestrial or via satellite) are: DVB-H(Digital Video Broadcasting Handhelds) DMB(Digital Multimedia Broadcasting) other technologies MediaFLO(Forward-Link-Only), developed by Qualcomm ISDB(Integrated Services Digital Broadcasting) are less important

21 DVB-H (Digital Video Broadcast for Handhelds) DVB-H is the extension of existing DVB-T(terrestrial) standard to support digital broadcasting of video streams to multiple handheld mobiles Formally accepted as the ETSI (European Telecommunications Standard Institute) in November 2004 DVB-H provides additional support optimized for mobile handheld reception, better battery saving mechanisms (using time-slicing), improved error protection for increased robustness of the transmission paths (support of devices with a smaller antenna) DVB-H could provide about 30 different TV channels over one full UHF channel, The biggest obstacle for DVB-H is the lack of available free UHF channels. In Europe DVB-H is strongly supported by important mobile device manufactures Seems to be THE WINNER!

22 Standards for DVB DVB-H Broadcasting to Handled extension of DVB-T with some backwards compatibility for the transmission to handheld receivers such as mobile telephones and PDAs. DVB-SH Satellite services to Handled Mobile TV over advanced Hybrid Satellite/Terrestrial Networks. Designed to deliver video/audio and data services to vehicles and handheld devices Services based on a TDM/OFDM radio interface and derived from the terrestrial broadcast DVB-H radio interface technology DVB-IPDC Internet Protocol Datacast Specifications for the Delivery of Mobile TV Services. DVB-IPDC is a set of systems layer specifications which define what is delivered, how it is delivered, how it is described, and how it is protected. DVB-T/DVB-T2(version 2) terrestrial (stationary) digital broadcasting DVB-S satelite based digital broadcasting

23 DMB (Digital Media Broadcast) An enhancement of the Eureka 147-DAB (Digital Audio Broadcast)standard, which was largely deployed (the coverage in Germany was about 80%). DMB uses a DAB channel with a bandwidth of about 1.5 MHz.This allows a simultaneous transmission of 3 to 4 TV channelswith a zapping time of roughly 0,5 seconds between channels Introduced in South Koreain May 2005, More than 7 million handsets, laptops, car navigators and other gadgets that are equipped with T-DMB receivers are in use. Used in Chinafor mobile TV services at the Beijing Olympics in Problems: Weak industry support in Europe and power consumption concerns.

24 MediaFLO (Forward-Link-Only) Is based on the Forward Link Only (FLO) specification for Terrestrial Mobile Multimedia Multicast (standardized as TIA-1099). MediaFLO is an end-to end system that enables broadcasting of video streams, audio-only streams,clip-cast media, and data-casting, to mobile devices, including handheld receivers Developed by Qualcomm. Very popular in USA.

25 Comparison of Competing Mobile TV Technologies

26 Mobile TV in Poland Telecommunication operator is INFO-TV-FM Limited Liability Company (established 2003) Provides its services for both public and commercial radio /television broadcasters. Made a head start of DVB-H services in September 2009 Info.: