bluetooth and java technologies in the wireless environment michael t. portwood, ms president &...
TRANSCRIPT
Bluetooth™ and Java™ Technologies
in the Wireless EnvironmentMichael T. Portwood, MS
President & CEO
Exuberance, LLC
Agenda
• What is Bluetooth™ wireless technology– Technology Overview– Weaknesses– Strengths
• What is Jini™ technology• Bluetooth, Jini™ technology, and the Wireless
Environment• Conclusion• Question & Answer
What is Bluetooth™Wireless Technology Overview
• Technology started by Ericsson• Named after 10th century Viking king
(Harald Blatand)• A global wireless technology specification• “Always on” communication• Radio frequency based• Inexpensive• Intended for …
– Portable devices– Desktop machines– Peripherals
Bluetooth™ Wireless Technology Details
• Baseband protocols– Circuit switching– Packet switching
• Uses 24 GHz globally available unlicensed ISM radio band• Effective range is 10 meters• Slow communication rate (721Kbps)• Small number of stations
– 8 devices / piconet– 3 voice channels
• Secure– Spread spectrum
Comparison ofWireless Technologies
Feature & Function Infrared 802.11Wireless LANs
HomeRF Bluetooth™
Connection Type Infrared, narrow beam
Spread spectrum
Spread spectrum
Spread spectrum
Spectrum Optical850 nm
RF
2.4 GHz
RF2.4 GHz
RF
2.4 GHz
Transmission Power 100mW 100mW 100mW 1mW
Data Rate 16Mbps 1Mbps,
2Mbps
1Mbps,
2Mbps
1Mbps
Range 1 meter 100 meters Typical home 3 meters
Supported Devices 2 127 8
Voice Channels 1 VOIP 6 3
Addressing 32 bit physical ID
48 bit MAC 48 bit MAC 48 bit MAC
Bluetooth™ Technology Strengths
• Inexpensive
• Superior range compared with IR
• Omnidirectional, not requiring line of sight
• Designed for ad hoc networking
• Both voice and data channels
• Well defined specification
• Large number of implementing companies
Bluetooth™ Technology Weaknesses
• Slow communication rate (1 Mbps)
• Short networking range
• Limited number of network connections
• Large and complex specification(over 1000 pages)
Bluetooth™ Wireless Technology Application Areas
• Pure computing applications– Presentations– Card Scanning– Synchronizing Data– Remote Synchronization– Printing– Scanners
• Ubiquous Applications– Communicator platforms– Electronic Books– Travel– Home Entertainment
• System Applications– In-vehicle systems
– Payment Systems
– Behavior Enforcement
– Collaboration
– Mobile E-commerce
What is Jini™ Technology
• Jini™ Technology is designed for reliable distributed computing
• Features– Simplicity– Reliability– Scalability
What Jini™ Technology is not
• Jini is not a name server
• Jini is not JavaBeans or Enterprise JavaBeans (EJBs)
• Jini is not RMI
• Jini is not a distributed operating system
Five Key Featuresof Jini™ Technology
• Discovery
• Lookup
• Leasing
• Remote Events
• Transactions
Discovery
• Discovery is the process of finding available lookup services
• The Jini discovery protocol is the means by which Jini-aware code finds Jini communities
Jini™ Discovery Protocols
• Multicast Request Protocol
• Multicast Announcement Protocol
• Unicast Discovery Protocol
Lookup
• Lookup refers to the things that you can do with the lookup services that are determined via discovery
• Lookup is similar to a name server– A process– Keeps track of all services that have joined a Jini
community
• Differs from a name server– Richer set of semantics than provided by traditional
name server
Lookup Actions
• Publishing a Service
• Downloading a Proxy
• Finding a Service
Leasing
• Leasing refers to the process of allocating resources to community members
• Leases are granted for a specified periodof time
• Addresses problems with network fragility
Remote Events
• Remote event is a technique for members of the community to notify one another of change
• Asynchronous notifications
• Consistent with events used in Java
Differences BetweenLocal and Remote Events
Local Events– Easier to deliver events
in the order that they were generated
– Always delivered
– Cost of delivery is low
– The sender knows that it can safely deliver the event to the consumer
Remote Events– Difficult to deliver
events in the order that they were generated
– Events may be undelivered
– Cost of delivery is high– The sender does not
know if it can safely deliver the event to the consumer
Transaction
• A transaction is a unit of work
• Transactions are used to complete complex units of work that may fail before complete
• Two phase commit
• Transactions are not heavily used in Jini™ applications
Transaction (cont.)
• Transaction provide…– Atomicity– Consistency– Isolation– Durability
Jini™ Key Concept Overview
• Discovery and Lookup establish a Jini community• Leasing helps Jini communities ensure stable, self
healing, and resilient networks in spite of inevitable network failure
• Events help Jini communities asynchronously communicate
• Transactions help successfully complete complex operations and provide resolution for incomplete operations
How Bluetooth™ Complements Jini™ Technology
• The key concepts found in Jini™ technology are found in Bluetooth™ wireless technology
• Bluetooth™ technology is hardware what Jini™ technology is to software– Platform independent– A “standard”– Widely accepted
Bluetooth™ and Jini™
• Both Bluetooth and Jini work well together– Ad hoc networking– Hardware specification complements software
specification, and visa versa– Broadly accepted technologies
Using Jini™ Technology
Additional Resources
• Bluetooth™ Wireless Technology– www.bluetooth.com
• Jini™ Technology– www.jini.org– www.javasoft.com
Conclusion
• Bluetooth™ and Jini™ technologies compliment one another
• Bluetooth™ technology excels at short duration ad hoc networking
• Jini™ technology complements Bluetooth™ Wireless Technology
• Many of the features of Jini™ technology can be found within the Bluetooth™ specification
Question & Answer
For Additional Information
• World Wide Web site– www.exuberance4me.com
• Presentation
• Presentation notes
• E-mail contact– [email protected]