Bluetooth and java a perfect match

1
Bluetooth and java a perfect match?

• Sean O Sullivan ceo
• Nordic Bluetooth, October 5th, 2001

2
overview

• Introduction to Java
• Java 2 Micro Edition (J2ME)
• The Standard Java Bluetooth APIs
• Jini and Javaspaces Service Discovery
• JXTA Peer to Peer

3
Introduction to Java

• Java is both a language and a platform
• Language
• Object oriented
• No pointers
• Compiled to Bytecode
• Executes on a Virtual Machine (VM)
• Wherever a VM can go so can Java
• The VM aspect of Java underpins the platform

4
Java 2 platform technologies
5
why care about java especially j2me?

• Momentum in the wireless world
• over 30 developers using Java for wireless
  Application Development()
• Equipment vendors backing it
• Nokia 150M Java Phones next 2 years
• Siemens Phones, PDAs shipping now
• Motorola Phones, PDAs shipping now
• Java complements Bluetooth
• provides core abstractions for service discovery,
  peer-to-peer and ad-hoc networking (see later)

Source Evans Data Corporation, 2000
6
Java 2 Micro Edition (J2ME) platform for
wireless

• Focus Wireless and Embedded
• Composed of
• Configurations
• Profiles
• Configuration
• Minimum set of classes and VM features that must
  be present for a category of devices
• Profile
• Targeted at Application Developers
• Layered on top of Configurations
• APIs for a particular set of devices

7
configurations and profiles
Java 2 Micro Edition

• Connected Device Configuration (CDC)
• Connected Limited Device Configuration (CLDC)
• Mobile Information Device Profile (MIDP)
• PDA Profile (PDAP)

8
CLDC is a subset of CDC
9
J2ME architecture key elements

• Profile
• API exposing the functionality on a specific
  class of target devices, and necessary to support
  a particular set of services
• Optional Package
• API exposing a specific functionality includes a
  list of API dependencies must be deployed with a
  profile that supports the dependencies
• Configuration
• the minimal sized, pre existing profile defined
  for the specific VM it is deployed against

10
CDC

• Targeted for devices that have
• 2 MB or more total available memory
• Memory dedicated to J2ME environment
• More than 2 MB ROM/Flash
• More than 512 KB RAM
• Network connectivity
• Full Java 2 VM specification (CVM)

11
smallest consumer devices CLDC and MIDP

• Smallest mobile information devices
• Cell phones, pagers, some PDAs, ...
• Small screensapproximately 100x100
• Limited battery life / low power consumption
• 128K to 512KB for J2ME environment and
  applications
• 16/32 bit processor
• Connectivity to some network, often not IP,
  intermittent

12
CLDC and MIDP

• CLDC provides
• A fast, small footprint virtual machine (the KVM)
• A stripped down Java API subset
• MIDP provides
• A set of User Interface components
• A persistence mechanism
• A HTTP connection capability
• A PDA Profile is being worked on (chaired by
  Palm)
• For use in mobile phones, PDAs and other handheld
  mobile devices.

13
standard Bluetooth APIs in Java JSR82

• Java Community Process (JCP)
• Issues Java Specification Requests (JSRs)
• JSR82
• Expert group to define Standardised Bluetooth
  APIs for Java
• Goal standardize a set of APIs to allow Java
  technology-enabled devices to integrate into a
  Bluetooth environment
• Chaired by Motorola
• Other members Rococo Software, Ericsson, Nokia,
  Extended Systems,
• Due for completion end 2001

14
JSR82 benefits for Bluetooth

• Portability of code
• Standard API allows same code to work on
  different devices, different Bluetooth Stacks
• Increases Bluetooth Adoption, reduces
  time-to-application
• Code in Java versus C, C
• Worlds fastest-growing Dev Community
• 2.5M Java developers worldwide

15
JSR82

• Target Platform
• Devices for the J2ME platform
• API will depend ONLY on CLDC APIs
• Use CLDC Generic Connection Framework
• APIs will work on all platforms that have/will
  have Generic Connection Framework

16
support for profiles

• Number of Bluetooth Profiles keeps growing
• API will provide support for the fundamental
  profiles
• GAP
• SDAP
• Serial Port
• GOEP (generic object exchange protocol)
• API assumes Bluetooth stack supports these
  fundamentla profiles

17
JSR82 profile support

• API to expose core layers and basic profiles
• 1. RFCOMM/SPP
• 2. SDP/SDAP
• 3. L2CAP
• 4. GAP/HCI/Device Management
• 5. GOEP

18
CLDC and Bluetooth architecture
19
CLDC and MIDP and Bluetooth architecture
20
JSR82 status

• Version 0.5 in September
• Community ReviewOct/Nov
• Public ReviewNov/Dec
• Release 1.0 - Jan 2001 (estimated)
• JSR and specification
• http//java.sun.com/aboutJava/communityprocess/jsr
  /jsr_082_bluetooth.html

21
Jini service discovery

• Pronouncing it
• Dont say Jinny, say Genie
• Jini
• Helps build and deploy distributed systems using
  federations of services
• A service can be anything any funtionality that
  a computer, device, person wishes to expose over
  the network

22
Jini architecture
23
Jini a service-oriented view of the world

• Allow late binding between client and service
• Allow services to change
• Enables reliable applications from unreliable
  parts
• Networked object components
• Breaks the tie between
• What is to be done
• Who is going to do it

24
Jini components

• Discovery Protocol
• Join Protocol
• Lookup Service
• Distributed Security System
• Distributed Transaction Interfaces
• Leasing Interface
• Event Notification Interfaces

25
service publishes proxy object
26
Where Jini and Bluetooth meet

• Both facilitate loosely-coupled networks where
  participants
• Join and leave the network regularly
• Discover and use services offered by other
  participants
• Can themselves offer services to the network
• Bluetooth provides the hardware/low-level
  software platform to allow dynamic networks to
  form
• Jini provides the higher level software framework
  to facilitate powerful application development

27
JXTA background

• Goal
• Build a small, lightweight platform as the
  foundation of all peer-to-peer systems
• Originated at Sun quickly moved to a neutral,
  community based organisation, and opensourced
• www.jxta.org

28
JXTA architecture
29
JXTA key concepts

• Peers and groups
• Any entity capable of the necessary protocols
• Advertisement
• Structured XML document
• Messaging
• Unreliable, asynchronous, uni-directional
• Pipe
• Virtual communication channel

30
JXTA protocols

• Discovery protocol
• Find advertisements from other peers
• Resolver protocol
• Locate peers, groups, pipes, etc.
• Information protocol
• Query other peers status

• Membership protocol
• Obtain membership information, apply, receive,
  and update group membership,
• Pipe binding protocol
• Bind a pipe advertisement to an actual endpoint
• Routing protocol
• Find a route to reach a peer

31
where Bluetooth and JXTA meet

• Bluetooth, by its very nature, faciliates
  peer-to-peer collaboration
• JXTA can provide a standard framework for
  peer-to-peer interaction
• JXTA may provide important technology to underpin
  2nd and 3rd generation Bluetooth applications

32
summary

• Java is important for Bluetooth
• Many BT devices will run J2ME as the core
  platform for applications
• Standard APIs for BT will speed new application
  development
• Ad-hoc and peer-to-peer technologies such as
  Jini, JavaSpaces and JXTA will provide software
  infrastructure that allows us to realise the
  potential of Bluetooth networks

33

• for more information contactSean O Sullivan,
  sos_at_rococosoft.com