1. SM2215 Genres Part 3 – The Internet Mark Green School of Creative Media

2. Introduction  The Web is the main form of Internet media, but there are other forms  Many of these forms are accessed through a browser, so they are often confused with the Web  Look at some of the more popular forms and their artistic, cultural and political applications

3. Streaming Media  Started with compression  Compressed video and audio, more efficient to send over network, basic file transfer  If compression is good enough can transfer in real time, a second of media can be transferred in less than a second  Only need to reconstruct it

4. Streaming Media  Two things are required: Real time transfer Real time transfer Real time reconstruction Real time reconstruction  The un-compression algorithm must be fast enough to run in real time  Be able to transmit and reconstruct the signal at the same rate it should be played

5. Streaming Media  Two modes of operation: On demand On demand Live Live  On demand: client connects to server and requests a particular media clip  Server then streams the clip to the client  Only two parties involved in the transfer

6. Streaming Media  Live: server is broadcasting a live event to a group of clients  Event could be an Internet radio station or a sports event  The media hasn’t been previously recorded, it is being sent as it is generated  many clients getting the same content at the same time

7. Streaming Media  On demand is easier and can be higher quality  Can preprocess the media, just transmit to single client when requested  Can adjust quality to available network bandwidth, tune the transmission to what the network can deliver

8. Streaming Media  Live involves the server sending a real time stream to many clients  Server must compress the stream as it occurs in real time  Then needs to send to all of the clients  Can require much more bandwidth and can’t tune the transmission to each client’s network connection

9. Streaming Media  Live broadcasts can go to thousands of clients, can’t have a separate connection for each client  Multicasting allows server to send one copy, automatically routed to the clients that want it  Much more efficient use of network bandwidth

10. Pirate Radio  Unlicensed radio stations: No government control No government control No royalties paid to record companies No royalties paid to record companies  Quite an old idea, based on low power transmitters that are easy to move  Most countries will try to shut down pirate radio stations, often work off shore

11. Pirate Radio  Why? Political message not popular with current government Political message not popular with current government Music that isn’t popular on commercial radio Music that isn’t popular on commercial radio Grass roots access to media Grass roots access to media Fun Fun  Transmitter based can be dangerous and difficult, moving to network radio

12. Pirate Radio  Stream from a server, could be a connection from a web page, or IP address distributed by email  Server can be in different country, or moved regularly to prevent blocking  Harder to find and shut down than transmitter based stations

13. Web Radio  Regular radio has limited range, can only reach local listeners  must be able to get large audience from local area  may not be possible for some types of music  music styles vary from one part of the world to another

14. Web Radio  Web radio removes regional restrictions, much larger population to draw on  two main implications: can build up audience for less popular styles can build up audience for less popular styles reach listeners outside of normal geographical area reach listeners outside of normal geographical area  can be exposed to a wider range of cultures  can send our culture further

15. Web Radio  Issues: are advertisers willing to pay? Most radio ads are local, need to look at global audience are advertisers willing to pay? Most radio ads are local, need to look at global audience royalties, where are they paid, who gets them? royalties, where are they paid, who gets them? How do we measure audience size, this is important for advertising and royalties How do we measure audience size, this is important for advertising and royalties  how should web radio be funded? Is advertising the right model

16. Business Models  How do we make money on internet services?  Advertising is the broadcast / print media solution, is it best for the internet?  Many sites use various forms of advertising and click throughs  seems to work for a few very popular sites

17. Business Models  Problems with advertising: software to remove adverts, not sure that user ever sees them software to remove adverts, not sure that user ever sees them developing a negative image, too much will chase users away developing a negative image, too much will chase users away hard to measure number of viewers, standard charging mechanism for adverts hard to measure number of viewers, standard charging mechanism for adverts how do local advertisers fit into the picture? how do local advertisers fit into the picture?

18. Business Models  Other possible models: sponsorship, have a small number of large companies sponsor the web site, minimal advertising sponsorship, have a small number of large companies sponsor the web site, minimal advertising subscription, each viewer pays a certain amount per year, best if voluntary subscription, each viewer pays a certain amount per year, best if voluntary donations and annual appeals, has worked well for public broadcasting in North America donations and annual appeals, has worked well for public broadcasting in North America

19. Peer to Peer  Most Internet services are based on the client-server model  There is a server that contains the information, multiple clients connect to it to receive information  The server is the central resource, stores all of the information

20. Server Model Server client

21. Server Model  Encourages broadcast, central server has all the content, sent to the clients on request  clients have no content  the server controls the interaction, the client plays a more passive role

22. Peer to Peer  In the peer to peer model there is no central server, or its plays a minimal role  The clients are directly connected together and share information  More of a two way flow of information, no centralized coordination, no special nodes in the system

23. Peer to Peer Model client

24. Peer to Peer Model  More of a communications model  one node doesn’t have control over the content, no monopoly on content  all nodes contribute to the content  applications tend to concentrate on communications, tend to be real time interactive

25. How is it Used?  Most high profile use is file sharing, originated with Napster, but there are other applications: file sharing file sharing resource sharing resource sharing communications communications

26. File Sharing  Napster allowed people to exchange MP3 files, share their music files with others  each user had a library of music files that they could share  problem was finding who had what file  Napster used a centralized model, a server maintained a list of who had which files

27. File Sharing  To find a file, send a message to the server  server responds with list of people with the files  connect to one of these computers, directly transfer the file from that computer  Napster server never stored any MP3 files, just served as a directory or search engine

28. File Sharing  Napster system had two benefits: no storage of MP3 files meant they were not directly guilty of copyright infringement no storage of MP3 files meant they were not directly guilty of copyright infringement did not need all of the disk space to store all the files did not need all of the disk space to store all the files  Napster still had major legal problems, but formed the model for future systems

29. File Sharing  Napster wasn’t the first file sharing system, Usenet started in 1979, used for both messaging and file sharing  based on newsgroups, each group is a sequence of messages on similar topics  newsgroups forms a hierarchy, but rarely more than 3 or 4 levels

30. File Sharing  New newsgroups are formed by a democratic process  group is proposed and anyone with an email account can vote on its creation  if vote passed, newsgroup is created  in the alt hierarchy anyone can create a new group, a form of organized anarchy

31. File Sharing  Usenet has no central server, no central storage  every system on Usenet exchanges messages with the systems it is directly connected to, messages spread over Usenet  message header ensure messages aren’t sent back to systems that already have them

32. File Sharing  Gnutella and similar systems get around one of Napster’s problems  no central server with file directory, the directory is shared by all the clients  each client maintains list of other Gnutella clients it knows about, can change dynamically

33. File Sharing  To find a file, send a message to other clients on our list  if a client has the file, responds with its address, otherwise it passes the request on to all the the clients it knows of  eventually will get responses with the clients that have file (if it exists anywhere on the network)

34. Resource Sharing  Can share more than files, can also share computer time  most of the time home computers aren’t used, they are idle, could be used for other purposes  the basic idea behind the SETI@home program

35. Resource Sharing  SETI is the search of extra terrestrial intelligence  based on recording signals from radio telescopes and then trying to find intelligence in them, some form of communications  requires very large amounts of computation, not available to researchers

36. Resource Sharing  SETI@home uses home computers to process the data  home computer requests a small part of the data, analyzes the data, and sends the results back to central site, repeats process  large network of home computers is more powerful than largest computers, and its free

37. Resource Sharing  Possible model for funding network services  provide a few hours of computing time in exchange for a service, i.e. web radio  some large computations are commercially important, companies will pay for time  sponsor services in exchange for computations

38. Communications  Instant messaging and similar systems provide a form of peer to peer communications  most of these systems are at least partially server based, but they support communications between two or more clients  in real time they can be peer to peer

39. Communications  Why do they need a server? Need to know how to contact other users, can roam between computers Need to know how to contact other users, can roam between computers need to know who is online need to know who is online store messages for users who aren’t currently online store messages for users who aren’t currently online  except for last point, the server can play a rather minor role

40. Communications  Without message storage, server only needs to know who is connected and how they can be contacted  this could probably be distributed in the same way as Gnutella, broadcast requests to known clients, etc  once friend is found directly connect to their client

41. Communications  Most instant messaging systems are commercial: server based, can keep track of users, charging is possible server based, can keep track of users, charging is possible proprietary protocols, can only talk to people on the same system, can’t send messages between systems proprietary protocols, can only talk to people on the same system, can’t send messages between systems  most systems are limited to text

42. Communications  Jabber: Open source protocol for instant messaging  originally developed as a bridge between other instant messaging systems  Jabber can support other media, such as sound and video, not clear whether any of the standard clients support this  could develop custom clients for art projects

43. Social and Political Issues  Sometime a political agenda associated with these services  political commentary in countries with tight media control  expression of unpopular opinions, possible legal or economic problems associated with views

44. Social and Political Issues  Two main concerns: censorship of online information sources censorship of online information sources anonymity for controversial messages anonymity for controversial messages  with a central server its very easy to block messages and web content, domain name and IP are well known  with many peers this isn’t possible, IP can change dynamically from day to day

45. Social and Political Issues  Only problem is knowing the current IP address, this can be done through email or through a broadcast mechanism like Gnutella  anonymous mailing systems make it impossible or difficult to trace origin of messages, can be used to hide the author’s identity

46. Social and Political Issues  With regular email can trace the author, can trace message back to machine where the message was created  to send an anonymous message, send to a special server, hides sender’s identity  can even reply to anonymous email, through the same server that sent it

47. Social and Political Issues  Can be used to protect people with important, but sensitive messages, assist political groups, etc  but, there is a negative side, same technology can be used by terrorists and criminals  can also be used to hide their activities, becomes a moral and ethical issue

48. Artistic Applications  Can we use this technology in an artistic way?  There are at least two applications: broadcast, distribution of art work broadcast, distribution of art work collaboration and performance collaboration and performance  Napster used to distribute commercial MP3s, why not use it to distribute other art works?

49. Artistic Applications  Could use file sharing systems to distribute video and music pieces  no need to have formal distribution channels, good for new artists and less popular art forms  avoid issues of censorship and artistic tastes

50. Artistic Applications  Instant messaging for artistic purposes?  Be able to collaborate in real time on creation of artistic pieces  easy to see with text, but this might not be the most interesting  adding sound and video gives a much richer environment, could use the same technology