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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”
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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” • 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 MANET • 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.
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.. • HiMoNN (Highly Mobile • Network Node) • Example of ad-hoc application for tactical and rescue services etc. a short range alternative for ad-hoc
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): • 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 • BEDDbuddies http://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