Wireless mesh shares MP3 files

Wireless mesh shares MP3 files
You pull up to a light, and the car next to you is playing a song you wish you could hear from the beginning. So you pull out your PDA, type in the title or the artist's name, and about 5 seconds later you are listening to that song. Your MP3 player cannot do that today. Your satellite radio will never do it. But you can do it in a wireless ad hoc peer-to-peer mesh network.

The song was delivered to you as an MP3 file. MP3 technology has led to the creation of new companies and new devices (Apple's iPod, SonicBlue's Rio series and Digit@lway's lipstick-size DMK), and enough litigation to keep a whole generation of lawyers employed. But all these companies fail to address mobile distribution-namely, how to make any audio file available anywhere, anytime.

The MP3 format exploded in popularity primarily because it allowed bandwidth-limited users to share music, particularly important for teenagers using a dial-up connection. But an MP3 player still has a finite amount of memory, so there is only so much music you can download to your PC and then upload into your MP3 player to take with you. In the MP3 format, 1 Mbyte is roughly equivalent to 1 minute of music.

By freeing users from the limited capacity of their local storage, an infinite amount of music becomes available. Streaming MP3s from network-based storage or from other MP3 devices can supplement or even replace the local storage of MP3 files on the device.

Some believe that 2.5- and third-generation cellular, which offer the promise of greater bandwidth than the cellular systems deployed today, may allow them to send and receive highly compressed MP3 files economically. But these cellular architectures will not support the peer-to-peer file swapping inherent to the Internet and existing MP3 swap sites. However, wireless ad hoc mesh networks do.

Our small company has developed a mesh routing technology that can enable mobile ad hoc networks. Each user device acts as a router/repeater for other devices. This means that users cooperate rather than compete for network resources. The device's ability to function as a router/repeater allows users to hop through other users to reach network access points. Hopping increases both the network throughput and the coverage area by leveraging users as part of the network.

This network architecture supports the ability to store MP3 files at home or on a network server, and then stream them wirelessly to cars, laptops, PDAs or wireless MP3 players. Users would also be able to share files directly with other users in an Internet-like wireless environment. We believe that this technology will result in most MP3 players being wirelessly enabled in the future. It also means that expensive, single-function satellite radios could be replaced by much less expensive and much more personal wireless MP3 players.

Mobile routers
Our company's networks operate in a distributed meshed architecture rather than the centralized hub-and-spoke design of traditional cellular telephone networks. This key is that the individual subscriber nodes-in this case, MP3 players, PDAs, laptops, automobiles-also act as mobile router/repeaters for neighboring nodes.

Wireless traffic is routed from the subscriber node to Intelligent Access Points that act as wireless or wired gateways. Traffic from the IAPs then is routed to the Mobile Internet Switching Center, which directs the packets to the voice public switched telephone network or to the Internet as needed. This switching center is also responsible for call control and other back-end operations.

The digital ASIC required for a device to ride on this mesh network is functionally equivalent to an 802.11 baseband chip. That is, it includes the modem, media-access control layer and our Ad Hoc Routing engine, along with resources that support network management and security. The ASIC interfaces to off-the-shelf RF transceiver chip sets on one side, and PC Card or CompactFlash interfaces to the subscriber host device on the other. Designed for battery-operated mobile devices, it operates with a 1.8-volt core and 3.3-V I/O, and includes low-power and sleep modes.

Such a network could improve both distribution and storage of digital audio, giving rise to new business models for the entire recording industry. The traditional value chain flows from artist to recording company, then is distributed to music stores and radio stations, and finally to the end listener. The future audio value chain will flow from artist to studio, then to MP3 clearinghouses and radio stations, and then to the listener. There are potential new revenue opportunities for organizations to act as clearinghouses that legally acquire MP3 files and digitally distribute them to subscribers and radio stations.

The recording industry successfully fought MP3 file sharing with its lawsuit against Napster. However, the recording industry has potential gains in this model, namely, acting as studios and clearinghouses. This will substantially reduce their costs of production, distribution and inventories, thereby considerably improving margins and profitability. The device's owner is known to the network operators. On-demand streaming MP3 also will end the annoyances of DJs, commercials, bad songs or searching for a few favorite tunes among a stack of CDs.

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