This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
SUN J2EE, W3C-XML, MS-.Netrevolution leading to web services
“Presence” a paradigm shift in Real Time Communications and CollaborationNet attached Consumer Electronics and Gaming appliances emergingApplications assuming always on connectivity
anytime, anywhere, anyhow accessibilityTerminal, Personal & Session mobility
end-device has a unique identifier communication independent from location realized by radio networks mechanisms: handover, location managementenables the user to utilize services from both stationary end-devices or from mobile end-devices
Individual mobility Concept realized by UPT (Universal Personal Telecommunication)
participant has a number identifying him uniquelycommunication independent from location and end-device participant can use any end-device to receive and to issue calls
Session mobilityparticipant can interrupt his session and later on continue at a different location
Deja Vu: Remember Infra-Red?A short-range wireless technology: a couple of meters Low-cost, reasonable data rate: 4 MBit/s (IRDA 2.0)Pushed by Hewlett-PackardMost laptops adopted itLots of cellphones and most palmtops have itBut no software for general connectivityEven HP printers don’t have IR ports!MORAL: a very nonlinear process
Value is low until most devices have it (cf. adoption of fax)People won’t bother with it until probability of benefit is high
+ cheap technology+ no license required - low transmission range (a couple of meters)
(large transmission range possible only with laser in point-to-point mode)
A little bit of historyThe Bluetooth SIG (Special Interest Group) was formed in February 1998 by 5 promoter companies
Ericsson,IBM, Intel, Nokia, ToshibaThe Bluetooth SIG went “public” in May 1998The Bluetooth SIG work (the spec: 1,600+ pages) became public on July 26, 1999 (ver. 1.0A)
ver. 1.0B was released on December 6, 1999ver. 1.1 was released on March 1, 2001
The promoter group increased in December 1999 to nine
added: 3Com, Lucent, Microsoft, MotorolaThere are 2,164 adopters (as of 3/15/2001)
adopters enjoy royalty free use of the Bluetooth technology
Topology Supports up to 7 simultaneous links Each link requires another cable
Flexibility Goes through walls, bodies, cloths... Line of sight or modified environment Data rate 720 Kbps Varies with use and cost Power 0.1 watts active power 0.05 watts active power or higher
Size/Weight 25 mm x 13 mm x 2 mm, several grams
Size is equal to range. Typically 1-2 meters. Weight varies with length (ounces to pounds)
Cost Long-term $5 per endpoint ~ $3-$100/meter (end user cost)
Range 10 meters or less Up to 100 meters with PA
Range equal to size. Typically 1-2 meters
Universal Intended to work anywhere in the world
Cables vary with local customs
Security Very, link layer security, SS radio Secure (its a cable)
Operates in the 2.4 GHz band at a data rate of 720Kb/s.Uses Frequency Hopping (FH) spread spectrum, which divides the frequency band into a number of channels
2.402 - 2.480 GHz yielding 79 channels Radio transceivers hop from one channel to another in a pseudo-random fashion, determined by the master. Supports up to 8 devices in a piconet (1 master and 7 slaves). Piconets can combine to form scatternets.
What is a Piconet?A collection of devices connected in an ad hoc fashion. One unit will act as a master and the others as slaves for the duration of the piconet connection.Master sets the clock and hopping pattern.Each piconet has a unique hopping pattern/ID Each master can connect to 7 simultaneous or 200+ inactive (parked) slaves per piconet
What is a Scatternet?A Scatternet is the linking of multiple co-located piconets through the sharing of common master or slave devices. A device can be both a master and a slaveRadios are symmetric (same radio can be master or slave)High capacity system, each piconet has maximum capacity (720 Kbps)
To enable the existence of a broad range of interoperable consumer devices, by establishing an open industry specification for unlicensed RF digital communications for PCs and consumer devices anywhere, in and around the home.
It is Targeted at home usersIntegration of voice and dataMultimedia supportBased on RFUnnecessary
2.4 GHz Frequency Hopping50 Hops per second radioOptimized for Voice & Data~1 Mbps real data rate (1.6 Mbps raw)Distance: 50m (House & Yard)4 near line quality voice linksUnlimited device links per basePeer-to-Peer networking"Native" TCP/IP supportLow power paging modeLower transmit power possibleBased on 802.11FH, OpenAir& DECTwww.homerf.org> 100 members (open IP but $4,800 fee)
Bluetooth (1.0A)2.4 GHz Frequency Hopping1600 Hops per second radioOptimized for Cell Phone, Mobile300-400 Kbps real data rateDistance: 10m (in-room Wire Replacement)3 near line quality voice links7 device links per baseMulti point-to-point connectionsPoint-to-point TCP/IP supportLow power standby modeHigher transmit power possibleBased on non-IP prototypewww.bluetooth.com> 1,000 members (It’s FREE !!!)
History1990 foundation of IEEE 802.11 Committee1991 first IEEE workshop "Wireless LAN"
1997 - 802.11 up to 2 Mbits (900 MHz)1999 - 802.11b 2.4GHz and up to 11 Mbits1999 - 802.11a 5 GHz and up to 54 Mbits200x - 802.11g 2.4GHz and up to 54 Mbits200x - 802.11x New Security
Wireless Technical TermEHF: Extremely High FrequencySHF: Super High FrequencyUHF: Ultra High FrequencyVHF: Very High FrequencyWLAN : Wireless LANIEEE: Institute of Electrical EngineeringARIB: Association of Radio Industries and BusinessCCK: Complementary Code KeyingOFDM: Orthogonal Frequency Division MultiplexingHIPERLAN: High Performance Radio LANETSI: Europe Telecommunications Standards InstituteBRAN: Broadband Radio Access NetworkWATM: Wireless ATMMMAC: Multimedia Mobile Access Communication SystemsMEDIAN: Wireless Broadband CPN (Computer Premises Network)/ LAN for Professional and Residential Multimedia ApplicationsFWA: Fixed Wireless Access
mobile IP adds mobility to the Internetdeveloped by the Internet Engineering Task Force (IETF)published as proposed standard in 1996 (RFC 2002), currently refined as RFC2002-bis
Mobile Node (MN):modifies access point in the Internet and currently running communicationsuses permanent IP address
Home Agent (HA):router in the home network of the mobile hostknows the mobile hosts, witch are not "at home" at the momentknows the current location of the mobile hosttunnels IP packets for and re-routes them to the mobile host’s location
Foreign Agent (FA): router in the foreign networkmobile hosts log on to the foreign agentsunpacks tunneled IP packets and re-routes them to their respective mobile hostassigns addresses (CoA) to the visiting Mobile Node
Correspondent Node (CN): Communication partner
Care of Address (CoA): Tunnel endpoint of the Mobile Node while abroad