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Gruppepresentasjon Virtual Transparent Directory with Mobile Ad-Hoc Networking. Henning Berg Jon Oldevik Lars Kristian Snellingen Bye Mansur Ali Abbasi Sven Jørgen Karlsen. Virtual Transparent Directory with Mobile Ad-Hoc Networking. Objectives Learning to ”ad-hoc” - PowerPoint PPT Presentation
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Gruppepresentasjon
Virtual Transparent Directory withMobile Ad-Hoc Networking
Henning BergJon Oldevik
Lars Kristian Snellingen ByeMansur Ali Abbasi
Sven Jørgen Karlsen
Virtual Transparent Directory withMobile Ad-Hoc Networking
• Objectives– Learning to ”ad-hoc”– Implementing a simple solution to ad-hoc file sharing
• Approach– Reading theory; books and articles– Defining a prototype
• File Sharing on a virtual ad-hoc network– Analysing usage areas– Implementing the prototype
• Expected results– Knowledge on mobile ad-hoc networking and bluetooth…
• Technology: J2ME, Bluetooth• Usage
– An implemented prototype– Documentation of results
Mobile Ad-Hoc Networking
• About ad-hoc– Latin phrase: for this purpose
– Also: refer to an improvised and often impromptu event or solution
• In computer networking– Ad-hoc is mostly associated with wireless devices.
– Requires no base station.
– Devices discover others within range to form a network
– Connections are possible over multiple nodes
– Devices out of range can be found by forwarding
– Routing protocols provide stable connections even if nodes are moving around.
• Example: Sony's PlayStation Portable uses Ad-Hoc connection for wireless
multiplayer gaming.
MANETMANET
More about MANETs
• Self-configuring network of mobile terminals connected by wireless links
– Which form an arbitrary topology.
• The terminals are free to move randomly and organise themselves arbitrarily;
• May operate standalone or be connected to a larger (Inter)net.
• Minimal configuration and quick deployment – Natural or human-induced disasters, military conflicts,
emergency medical situations etc.
• Earliest MANETs were called packet radio networks
– Sponsored by DARPA in the early 1970s..
a short range alternative for ad-hoc
HiMoNN (Highly Mobile Network Node)• Example of ad-hoc application for tactical and rescue services etc.
Prototypeapplikasjon –Transparent Virtual Directory (TVD)
• Fildelingstjeneste der alle nodene i et ”tilfeldig” nett skal kunne dele filer med hverandre ved bruk av Bluetooth-kompatible enheter
• Skal brukes som grunnlag for resonnering om ad-hoc nettverk
• Flere problemområder knyttet til ”spontane” nettverk. Blant annet: – Master/slave-problematikk (server/klient)– Ruting– Filreplikering og eierskap av filer– Lastbalansering– Filforwarding
Virkemåte til TVDTre scenarioer som kan beskrive de fleste situasjoner (ved å kombinere disse):
1. To noder i et nett hvor ‘node A’ ønsker å laste ned to filer som befinner seg fysisk på ’node B’Tre noder i et nett hvor ‘node A’ ønsker å laste ned en fil fra ‘node B’ og en fil fra ‘node C’Tre noder i et nett hvor ’node A’ og ’node B’ er innenfor rekkevidde av hverandre, og ’node B’ og ’node C’ er innenfor rekkevidde av hverandre. ’Node A’ ønsker å laste ned en fil fra ’node C’.
Scenario 1: To noder, ’node A’ ønsker å laste ned to filer fra ’node B’
Scenario 2: Tre noder, ’node A’ ønsker å laste ned en fil fra hver av de to andre nodene i nettet
Scenario 3: Tre noder, ’node A’ ønsker å laste ned en fil fra en node som ikke er direkte tilgjengelig for ’node A’
Problemområder:
-
Master/slave-problematikk, ruting, lastbalansering og filforwarding:
- JSR82 som spesifiserer bruken av Bluetooth i J2ME-applikasjoner indikerer en master/slave-kategorisering av enheter- Mange noder i et nett kan føre til at mye av båndbredden blir brukt til kontrollpakker- Mobiler og PDAer har begrenset med prosessorkapasitet og minne, og store, tunge rutingsprotokoller kan bli et problemVi tror en reaktiv point-to-point (hop-by-hop) rutingprotokoll vil være best for TVD. En gitt rute blir funnet når den trengs Vil trolig benytte JBAN – et rammeverk som fjerner master/slave-problematikken, lastbalansering og har innebygd ruting
Problemområder:
Filreplikering og eierskap av filer
- Vil begrense oss til at kun én node i et nett kan dele ut en fil med et gitt filnavn. Andre noder som laster ned denne filen vil ikke uten videre dele denne ut
Usage areas of Ad Hoc networking
• Social services– Dating, chatting
• Work related / ”useful” areas– Emergency areas
– Military operations
– Sensor Networks
• Entertainment– Gameplay
• Information sharing– File sharing
– Streaming media services
– Commercial and sales
Usage areas of TVD
• Sharing of image and music files• Comercials / product information• Work situasions
– Document sharing
– Collecting data from nodes
Example usage scenario of TVD
• Document sharing between coworkers at a meeting:– No papers
– No possibility to forget / loose links
– Don’t need to bring a big laptop, the cell phone is enough.
BEDD (Bringing People Together)
• BEDDmates
• BEDDpic
• BEDDbay
• BEDDtalk
• BEDDfish
• BEDDbuddieshttp://www.bedd.com
Other Related Ad-Hoc Bluetooth Applications
• Mobiluck (http://www.mobiluck.com/)
– Sending messages and photos other to bluetooth users
• ProximityMail (http://www.inventop.com/index.htm)
– Group-based message sending / subscription
• MeetingPoint (http://www.net-cell.com/MP/index.html)
– Channel-based contact application (messaging)
• Freejack and sMan– ”Bluejacking” software
Bluetooth - background• Bluetooth is a wireless standard for interconnecting devices, using
short -range, low-power, inexpensive radios. – Radio: 2.4 Ghz ISM band, license-free. 79 (23) channels of 1 Mhz. Gross rate <= 1
Mbits– Original idea: To get rid of the cables between devices (similar to infrared
networks)Soon expands in scope and overlaps with WLAN and IR networks.
– 13 profiles (applications) built on stacks of more than 9 protocols.
• History:– 1994: Ericsson initiated a SIG (special interest group) together with IBM, Intel,
Nokia and Toshiba, to std. connecting mobile phones with other devices without cables.
• Named after Harald Blåtann II (940-981), a danish Viking king who unified Denmark and Norway (a brief period, between Harald Hårfagre and Olav the Saint).
– 1999: V1.0 released in 1500 pages (!). Triggers a parallell effort in IEEE 802.15, which looks at WPANs, but only std. the physical and data link layers. Purpose: Open std. managed by a neutral body.
– 2002: 802.15.1 approved by IEEE.– 2004: V2.0 Core spec. with EDR (up to 3 Mbits speed) released.– Present/Future: The two stds. will converge?
Bluetooth - architecture
• Piconet: basic building block of a Bluetooth system– One master node, and up to7 active slave nodes (up to 255 parked nodes), <= 10 meters apart. – All communication goes through the master, direct slave-slave is not possible. The slaves are fairly dumb,
basically just doing doing whatever their master tells them to do.– Technical note: a piconet is a centralized TDM system, with the master controlling the clock and allocating
time slots.
• Scatternet: interconnected piconets, via bridge nodes.
Bluetooth – protocol stack
• Service Discovery Protocol (SDP): Inquire about services, find out how to access● Object exchange (OBEX) Support “object exhanges”, basis for Synchronization Profile and File Transfer Profile.● Radio Frequency Communication (RFComm): Emulates the std. serial port (RS-232) on PCs for integration with legacy devices.● Logical link control adaptation protocol (L2CAP) Packet intf. to higher layers (m/s roles hidden at this layer), packet segmentation and reassembly. Multiplexes several logical channels over one physical link.
J2ME – Java Platform, Micro Edition
• What is it?– A set of technologies and specifications for small devices
– Small-footprint subsets of Java SE components
– Smaller virtual machine and leaner APIs targeted at consumer and embedded devices
• Why suitable for us?– Java Bluetooth API
– Open, non-proprietary standard for bluetooth application development
– Hides complexity of Bluetooth and allows focus on application development
J2ME – Java Platform, Micro Edition
Not so MICRO after all…?
JBAN – A potential pain reliever?
• Pain:– The process of forming a scatternet out of piconets is usually not dynamic and practical– The scatternets formed are not robust– Routing and network management causes a lot of headache for the developer
• Pain relief:– JBAN: a open source Java library for Bluetooth networking– Provides a new way to form an ad-hoc network at the Java application level– Allows unlimited devices to form a network dynamically– More robust networks, no distinction between master and slave nodes– Routing and network management is performed at high level
• Possible pitfalls:– JBAN is relatively new (more or less a bundle of code in jar-file)– “Released” February 2006, no documentation, no reported experiences– May require some “hacking” to make it work the way we want it to
• To use or not to use?– No pain no gain…JBAN may help increase the gain and reduce the pain– Decision: Let’s try it out!
Project status
• So far so good:– Focused on background reading and understanding the technology
and tools– Evaluated and abandoned several ideas before TVD:
• Triangular positioning of Bluetooth nodes• Solutions for crisis management / emergency warnings
– Now have a well elaborated, feasible idea: TVD– No external collaboration = free, independent development
• The path forward:– Ready to embark on coding / implementation
• Work in smaller subgroups, iterative• Testing in a Bluetooth network simulator?
– Will result in greater theoretical and practical insight into Mobile Ad-Hoc Networking and especially Bluetooth+J2ME
– If successful in implementation and testing, further development may be interesting (perhaps as a open source project)
Future of Bluetooth
• Advancements in progress– Larger range
– Higher transfer speeds
– QoS improvements
– Will become more feasible for more sophisticated use