Audio Networking

1. Audio Networking Bob Moses AES Vice President Western Region USA/Canada Updated: May 21, 2002

2. Presentation Outline • Why Network Audio? • How? • Ramifications • Listening Tests

3. Why Network Audio? Put an engineer, marketing exec., business development mgr, and consumer in a room and ask them “why network your audio system?” • Engineer:“Because we can” • Marketing:“To exploit new opportunities” • BizDev:“To make lots of money” • Consumer:“To access every recording ever made, instantly”

4. Engineering Perspective • Digital Audio systems benefit by being networked • Share resources • Lowers cost • Increases performance • Provide a modular upgrade path • Partition the system so that only those things that need to change must change • Enhanced user interface • Graphical • Single and multiple points of control

5. Engineering – Anatomy of a modern audio widget

6. Evolution – the PC meets Darwin Jim Reekes, Founder of Kebango: “A general-purpose computer is an instrument of torture. They do many things, but nothing very well. They paradoxically implement a continually changing set of standards. Of the top 10 selling software packages, 6 cure problems created by other programs.“

7. Introducing the “Home Network” • Carries all types of data • Files (TCP/UDP, SCSI, etc.) • Audio streams (MP3, Real, WMA, Dolby/DTS, Redbook, 24/96, multichan, etc.) • Video streams (Real, MPEG4, uncompressed SD & HD, MPEG PS or TS, DV, etc.) • Control & monitoring protocols (RC5, AVC, ASCII, JAVA/Jini, UPnP, proprietary, etc.) • Transparent to the data • Quality of service for streaming A/V exceeds human perception (bounded latency, low jitter, no drop outs) • Guaranteed delivery with handshaking, retries, time outs, etc. • Consumer friendly • Low cost • Easy to set up and use • Robust • Secure, but not finicky

8. Many Contenders for the Home Network • IEEE 1394 • Ethernet • IEEE 802.11a • HomeRF • HomePNA • HomePlug • Etc. More details later….

9. IEEE 1394 in A/V System Ethernet in Home Office Ethernet or Wireless 1394 backbone Broadband Internet Gateway Example Home Network

10. Marketing – New products! • Information Appliances Personal computers • Home Internet terminals • Personal digital assistants • Digital mobile telephones • Boom boxes • Digital Jukeboxes • Internet Radios • Set top boxes • Wrist watches • Etc., etc.

11. Business Development – More money! • 41% of US households are now online (US Dept Commerce, 2002) • 71% of U.S. households will be online by 2003 (Forrester) • 18,000,000 people have broadband at home now; grew 121% in 2000-2001 (Arbitron/Edison Media) • 34% of U.S. population regularly streams music today (Arbitron/Edison Media) • 40% of U.S. population will be listening to Internet radio by 2003 (Webnoize) • Digital downloads will grow from 3% of online music sales in 2001 to 30% in 2006 (Jupiter Media Metrix) • The market for smart handheld devices will grow from 12.9 million units in 2000 to over 63.4 million by 2004 (IDC) • The worldwide market for information appliances will exceed 89 million units, or $17.8 billion, in 2004, up from a market of 11 million units and $2.4 billion in 1999 (IDC) • Napster enlisted more users in 1 year than AOL did in 15 years.

12. Broadband – The Next “Big Thing” • Broadband Internet access is booming • 51% of the 2.3 billion hours spent online in the month of January 2002 were via broadband, outpacing dial-up Internet access for the first time. • Forrester Research predicts that 38 million European homes will have broadband Internet access by 2006. • An estimated 13.4 million homes in North America have high-speed connections now, and the US Government is being heavily lobbied to raise that to 80% by the end of 2003. • Many devices want access to Broadband services,necessitating a home network • Multiple PCs for various members of the family • Streaming and downloadable media (MP3, Real Video, etc.) • Music metadata look up services (e.g. CDDB) • Gaming • Intelligent appliances

13. Home Networking is on the Rise • 12 million homes expected to have home networks by 2004 (Parks Associates) • Most popular reasons for a home network (HomeRF) • Sharing high speed internet – 39.1% • Sharing dial up internet account – 37.2% • Sharing printers – 34.7% • Sharing audio – 33.3% • Sharing files – 31.8% • Sharing drives – 26.4%

14. Where did this come form? • The Internet found a killer app – digital music • immediate gratification! • transcends all cultures, ages, and personal preferences • portable, cheap, low power, tremendous access • Convenience vs quality • Leverage advances in • Larger/cheaper memory • faster CPU speed • broadband Internet access • portability • Convergence • Computer industry trying to entice consumers • Consumer industry trying to sell new products • Music enthusiasts trying to access vast amounts of music • Musicians trying to reach listeners (95% of the music is owned by five large companies. Only 5-10% of the money you pay for a CD goes to the artists. )

15. New Business Models • The CEO of the Consumer Electronics Association recently stated, “The content industry wants to turn the ‘Play’ button into a ‘Pay’ button” • Subscription services (AOL, MSN, Napster, etc.) • Music lockers (my.mp3.com) • Peer to peer networking • Napster • Fastrack / MusicCity/Grokster (1.5 billion illegal downloads in Sept 2001!) • Gnutella • Audio Galaxy • Hardware is a loss leader • What does that mean for audio quality? • Brick and Mortar stores – are they going away?

16. Online Music Services • Real Networks • MSN Music • mp3.com • Live365 • Shoutcast • Icecast • Loudeye Radio • Yahoo Music • Napster • etc.

17. How do we network Audio? • Two methods: Streaming and File Delivery • Streaming – synchronous, uninterruptible flow of audio • File Delivery – asynchronous, interruptible • Streaming is higher quality, but places higher demands on the network • File transfer is easy and cheap, but requires compression of the audio data for practical systems (today)

18. Networks that Stream • IEEE 1394 • Simple, cheap, consumer-oriented • Short distances (<1km) • Super high performance • Cobranet (Ethernet) • Proprietary • Expensive • Pro audio applications only • ATM • Expensive • Lack of standards for applications • Optimized for wide area

19. Networks that transfer files • Ethernet • IEEE 802.11 • HomePlug • HomePNA • IEEE 1394

20. Home Networking Technologies – Ethernet • Supports: • Ubiquitous - 300 million Ethernet nodes worldwide! • Supports speeds up to 10 Gbps • CSMA/CD protocol allows asynchronous transport, breaks down during heavy networking loading • Like 1394, Ethernet supports: • Most physical media – copper, fiber, wireless • A peer to peer architecture that allows any node to communicate with any other node, without PC intervention • Low cost chipsets from many silicon vendors

21. 10 Mbps 100 Mbps Gigabit 10 Gigabit CAT UTP 100 m 100 m 100 m no STP / Coax 500 m 100 m 25 m no Multi mode fibre 2 km 412 m (half duplex) 2 km (full duplex) 550 m 300 m Single mode fibre 25 km 20 km 5 km 40 km Home Networking Technologies – Ethernet

22. Standard Frequency Band Available Spectrum Data Rate Range & Data Rate IEEE 802.11b 2.4GHz 83.5 MHz 11 Mbps 100 meters @ 11 Mbps IEEE 802.11a 5.6 GHz 300 MHz 54 Mbps 50 meters @ 9 Mbps IEEE 802.11gOFDM 2.4GHz 83.5 MHz 54 Mbps 100 meters @ 12 Mbps IEEE 802.11gPBCC 2.4GHz 83.5 MHz 33 Mbps 100 meters @ 11 Mbps Home Networking Technologies – IEEE 802.11 • Wireless Ethernet • Collision sensing multiple access / carrier avoidance protocol • “Wired Equivalent Privacy” (WEP) security via authentication and encryption. There have been recent reports that this security has been compromised by hackers. • Several Flavors:

23. Home Networking Technologies – HomeRF • Competes with IEEE 802.11 for wireless Ethernet applications • Uses Shared Wireless Access Protocol (SWAP) • Operates in 2.4 GHz band, up to 100 meters, up to 10 Mbps.  • Supports up to 8 simultaneous voice connections with 10 ms bounded latency. • 128-bit encryption with tamper-resistant 32-bit initialization vector

24. Home Networking Technologies – IEEE 1394 • Nearly ideal for home networking • Up to 400Mbps (1394a), or 3.2Gbps (1394b) • Up to 63 nodes per bus, and up to 1023 buses connected via bridges (per 1394.1 standard) • Isochronous transport handles up to 64 isoch streams per bus • Asynchronous transport addresses up to 256 terabytes on every node • Supports most physical media – copper, fiber, wireless • Peer to peer architecture allows any node to communicate with any other node, without PC intervention • Supports international standard protocols for all relevant audio / video formats, TCP/IP, storage devices, device control, and so on. • Adopted by hundreds of companies and most industry consortiums for next-generation digital appliances • Low cost chipsets available from many silicon vendors

25. 1394b Distance 100 Mbps 200 Mbps 400 Mbps 800 Mbps 1.6 Gbps 3.2 Gbps CAT-5 100m X POF 50m X * HPCF 100m X * GOF 100m X X X X X X STP 4.5m X X X X X X Home Networking Technologies – IEEE 1394 • Physical Constraints * Against the rules, but it works

26. Home Networking Technologies – Wireless IEEE 1394 • IEEE 802.11a carries 1394 isoch and async traffic • Or, HiperLAN2 can be used too • 54Mbps, good enough for 1 or 2 MPEG streams and lots of audio channels • Currently under development, demos have been made for several years at various trade shows

27. Home Networking Technologies – HomePNA • Home Phoneline Networking Alliance (HomePNA) • 4MHz – 10MHz band (well above POTS) • 25 devices, up to 500 feet apart, in buildings up to 10,000 square feet • HPNA 1.0: Data rate up to 1 Mbps • HPNA 2.0: Data rate up to 10 Mbps • Interoperable with Ethernet and IEEE 802.11 / HomeRF

28. Home Networking Technologies – HomePlug • Home Plug Alliance selected Intellon technology for HomePlug specification: • Operates over regular 2 phase power circuits • OFDM in the 4.3MHz – 20.9MHz band. • Data rate up to 10 Mbps • MAC protocol is a variant of the well-known CSMA/CA protocol. • Up to 256 devices can be connected in homes up to 5,000 SQFT • Security is provided by encryption and signal attenuation. However, powerline technologies are often accessible to neighbors sharing the same transformer.

29. Which Network(s) Should I Use? • Data: Ethernet, 1394, 802.11, HomePNA, HomePlug • Audio: • Compressed: Ethernet, 1394, 802.11, HomePNA, HomePlug • Streaming: 1394 • Video: • Compressed: Ethernet, 1394, 802.11, HomePNA, HomePlug • Streaming: 1394

30. Heterogeneous Networks • No network is perfect, and no single network will win universal adoption • Heterogeneous networks are comprised of two or more network technologies • Bridges and gateways are crucial devices for connecting “subnets” • Bridges connect two or more networks running the same protocol stack (e.g. HomePNA to Ethernet) • Gateways connect networks that use different protocols (e.g. Ethernet to 1394) • Heterogeneous networks allow us to add functionality to the home network incrementally • e.g. begin with an Ethernet PC LAN • Add 802.11 or HomePNA to reach remote zones • Add 1394 to distribute A/V • Replace original Ethernet with 1394b to increase speed and QoS

31. Ramifications • Systems evolve from autonomous devices to communities of devices. • Control becomes decentralized and migrates to the edge devices. • This is a revolutionary change (not evolutionary)

32. Paradigm Shifts • Once there is too much information to own, we must evolve methods to access and organize it. • Today’s systems are equipment-centric, and very complex. • Tomorrow’s systems need to be content-centric, and very simple. • The distinction between ownership, and renting, and a service is already blurred in the video industry. That’s likely to happen in the music industry as well. • Duplicating and distributing plastic disks is barbaric.

33. The user interface gets really cool!

34. Content-Based Searching Chris Weare & Ted Tanner: • Breakthroughs in machine learning, pattern recognition, and feature extraction can be applied to audio to characterize the similarity between two recordings. • A neural network was trained with data from over 115,000 songs to produce a commercial system that provides over 90% success. • Humans no longer need to listen to music because computers can be trained to listen for them!

35. Content Protection • Copy inhibit bits (SCMS) • Watermarking • Fingerprinting • SDMI • DTCP Do any of these technologies truly work? Should we create technical solutions to legal problems, or legal solutions to technical problems?

36. Metadata Elizabeth Cohen: • We generate terabytes of new music data each day • The machine and format I record on today won’t be around in 20 years. • It’s important to preserve the music experience itself, not just the bitstream “How do you record and regenerate an experience”? • Some of our audio treasures might be lost when future devices are unable to play them back. • Elizabeth Cohen recommends that if a device leaves a footprint on the audio, the content must describe it via metadata.

37. Don’t forget about the Creative Team During Encoding! Bob Clearmountain: • Producing content for the Internet is not merely a file transfer process – creative decisions must be made in the mastering process that ultimately affect the listening experience. • The process of compressing audio for the low bandwidth of the Internet is very similar to the old days of squeezing music into a plastic groove of a vinyl LP during mastering, and that the compromises involved should be a creative process involving the creative team. • Internet mix should also be considered in addition to the CD, radio, extended dance mix, and other mixes.

38. Most important ramification – Audio Quality • Better or worse? • Streaming networks promise to carry data between devices in their original format without A/D and D/A conversion. • File delivery systems must compress the data. This is a violent process that significantly changes what we hear!

39. Compression Formats • Required for asynchronous networks • MPEG-1 Layer 3 (MP3) • MPEG 2, 4, MPEG 7 • AAC • Windows Media • Real Audio/Video • Quicktime • Ogg Vorbis • VQF • Beatnik • etc.

40. Listening Tests • Edward II: Wicked Men • Track #7: She’s Gone to California • Original (44.1kHz, 16-bit) • Compressed Formats • MP3 • WMA 7.0 • Real Audio 6.0 • (AAC can not be played back due to copy protection glitch) • 160Kbps • Random ordering • 64Kbps • Random ordering